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Sample records for spiny-cheek crayfish orconectes

  1. Evaluation of different marking methods for spiny-cheek crayfish (Orconectes limosus

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    Buřič M.

    2008-10-01

    Full Text Available Different methods of marking were evaluated for Orconectes limosus (CL = carapace length, 12–37 mm under laboratory conditions: the use of passive integrated transponders, visible implant elastomers, visible implant alphanumeric tags, and cauterization. High survival (> 90% was obtained with all methods tested. Tag retention and readability were evaluated immediately after marking, before and after ecdysis, with moult increments and number of moults been recorded. Marking using cauterization negatively affects the percent moult increment (PMI of crayfish. The average PMI of 15 ± 0.88% did not differ between males (15 ± 1.41 mm and females (15 ± 1.12 mm. It was found that PMI gradually decreased with an increase in CL. Sixty-one moults were observed, with 12 crayfish (6 juveniles and 6 adults presenting two moults. Time between moults varied from 3 to 7 weeks. CL was increased with over 28 ± 2.68% due to two moults. Three females moulted twice after successful hatching and carrying of juveniles.

  2. Heavy Metals Bioaccumulation in Tissues of Spiny-Cheek Crayfish (Orconectes limosus) from Lake Gopło: Effect of Age and Sex.

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    Stanek, Magdalena; Dąbrowski, Janusz; Różański, Szymon; Janicki, Bogdan; Długosz, Jacek

    2017-06-01

    The aim of the present work was to assess the concentrations of metals in the abdominal muscle and exoskeleton of 3-year-old males and 4-year-old females and males of spiny-cheek crayfish (Orconectes limosus) collected from Lake Gopło. A total of 93 males and 35 females were collected in autumn (October 2014). The analyzes of heavy metals were conducted by means of atomic absorption spectroscopy with a PU9100X spectrometer. The content of mercury was determined using AMA 254 mercury analyser. As analyses indicated heavy metals accumulated in the muscle and exoskeleton in the following sequence: Zn > Cu > Pb > Mn > Ni > Hg and Mn > Pb > Zn > Ni > Cu > Hg, respectively. Statistically significant differences between 3- and 4-year-old males were found for all analyzed metals. Gender dependent differences were calculated only for Ni in the muscle tissue and for Mn and Hg in the exoskeleton. In comparison with the study carried out 2 years ago notably higher concentrations of Pb were found in the muscle and a higher content of Zn, Pb, Mn and Ni was determined in the exoskeleton.

  3. Temporal variation in the prevalence of the crayfish plague pathogen, Aphanomyces astaci, in three Czech spiny-cheek crayfish populations

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    Matasová K.

    2011-06-01

    Full Text Available North American crayfish species are natural hosts of the crayfish plague pathogen Aphanomyces astaci. The spiny-cheek crayfish Orconectes limosus, widespread in Central Europe, is the main reservoir of A. astaci in Czech Republic. We tested if there are temporal changes in the prevalence of infected individuals (i.e., the proportion of individuals in which the pathogen is detected in spiny-cheek crayfish populations. Crayfish from three populations shown previously to be infected to different extents (high, intermediate and low, were repeatedly sampled in different years (2004–2010 and seasons. The presence of A. astaci in the soft abdominal crayfish cuticle was tested by specific amplification of the pathogen DNA. There was no substantial temporal variation in pathogen prevalence in the highly and very lowly infected populations. However, a significant long-term as well as seasonal decrease was found in the intermediately infected population. This decline could be related to a decrease in population density over the studied years, and to crayfish seasonal moulting, respectively. A reliable estimate of pathogen prevalence in American crayfish populations thus requires repeated monitoring over years, preferably during the same season before the main period of crayfish moulting.

  4. Temporal variation in the prevalence of the crayfish plague pathogen, Aphanomyces astaci, in three Czech spiny-cheek crayfish populations

    Czech Academy of Sciences Publication Activity Database

    Matasová, K.; Kozubíková, E.; Svoboda, J.; Jarošík, Vojtěch; Petrusek, A.

    -, č. 401 (2011), s. 1-9 ISSN 1961-9502 R&D Projects: GA MŠk LC06073 Institutional research plan: CEZ:AV0Z60050516 Keywords : crayfish plague * molecular methosd * dominance Subject RIV: EH - Ecology, Behaviour Impact factor: 1.520, year: 2011

  5. Preliminary Data on the Ecological Requirements of the Invasive Spiny-Cheek Crayfish in the Lower Danube

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    Pîrvu Mălina

    2014-12-01

    Full Text Available Water quality and properties of the riverbed often shape the community structure of aquatic ecosystems, occasionally sustaining the expansion of non-native species. This study aims to provide preliminary data on the ecological preferences of the invasive species Orconectes limosus, its control, and the protection of the native stock is an European priority. In order to assess the species ability to colonize small river systems, relevant tributaries in the invaded Danube sector were monitored. Statistical test indicates a preference for deep and warm rivers, low water velocity and also high concentrations of calcium.

  6. Tritium uptake kinetics in crayfish (Orconectes immunis)

    International Nuclear Information System (INIS)

    Patrick, P.H.

    1985-06-01

    Uptake of tritiated water (HTO) by Orconectes immunis was investigated under laboratory conditions. Tritium uptake in the tissue-free water fraction (TFWT) was described using an exponential model. When steady-state was reached, the ratio of TFWT to HTO was approximately 0.9. Uptake of tritium in the organically-bound fraction (OBT) proceeded slowly, and had not reached steady-state after 117 days of culture. Although steady-state was never reached, the maximum observed ration of OBT to TFWT in whole animals was approximately 0.6. However, this ratio exceeded unity in the exoskeleton. Specific activity ratios of OBT between crayfish and lettuce (food source) were less than or at unity for various test conditions

  7. Invasion of an occupied niche by the crayfish Orconectes rusticus: potential importance of growth and mortality.

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    Hill, Anna M; Sinars, Damon M; Lodge, David M

    1993-06-01

    We are exploring mechanisms of an invasion that contradicts the oft-cited generalization that species invade vacant niches. In northern Wisconsin lakes, the introduced crayfish Orconectes rusticus is replacing two ecologically similar resident congeners, O. virilis and O. propinquus. In laboratory experiments, we compared growth and mortality of individually maintained crayfish offered one of five ad libitum diets: invertebrates, macrophytes, dentritus, periphyton or all items combined. Mortality was highest for O. virilis and lowest for O. rusticus. Macrophyte diets yielded the highest mortality. All three species grew best on invertebrate and combination diets but grew little or not at all on diets of periphyton, detritus or macrophytes. O. rusticus and O. virilis grew more than O. propinquus. O. rusticus grew more quickly and/or was better able to survive overall than its congeners. Therefore, O. rusticus would probably have advantages over O. virilis and O. propinquus in competitive interactions, reproductive success and avoiding size-selective fish predation. Subtle interspecific differences may interact strongly with other ecological factors and contribute to the displacement of resident species from a well-occupied niche.

  8. Increased microsporidian parasitism of the crayfish Orconectes virilis in an experimentally acidified lake. [Thelohania contejeani

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    France, R.L.; Graham, L.

    1985-10-01

    Orconectes virilis has been identified as a host of the microsporidian Thelohania contejeani in four lakes in the Experimental Lakes Area (ELA), northwestern Ontario. Prevalence of parasitism increased from 1.7% in autumn 1979, to 6.5% and 7.7% in autumns 1980 and 1981 concomitant with experimental acidification of Lake 223 to pH 5.1. By comparison, mean infection rates observed within three reference lakes were between 0.3 to 0.6%. Enhanced microsporidosis is believed to have contributed to a reduction in annual crayfish survival rates for the Lake 223 population of 8% in 1979 and 18% in 1980 compared to averages calculated for the non-acidified lakes. Hypotheses to explain the ten-fold increase in Thelohania parasitism in Lake 223 over background levels for the ELA region include a) increased probagative ability due to elevated rate of crayfish cannibalism or low pH-favored parasite life cycle, and b) decreased host resistance when under sublethal stress.

  9. Laboratory and field assessment of uranium trophic transfer efficiency in the crayfish Orconectes limosus fed the bivalve C. fluminea

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    Simon, Olivier; Garnier-Laplace, Jacqueline

    2005-01-01

    At present, ecotoxicological information regarding the impact of natural uranium (U) on freshwater ecosystems via the trophic contamination route is scarce. We generated an experimental trophic food chain involving the prey species, Corbicula fluminea, and a predator, Orconectes limosus, for a 10-day and a 30-day feeding periods (food ration: one whole soft body/day/crayfish). We studied the efficiency of U trophic transfer and the distribution of U in the predator. During the test, we varied the quantity of dietary U (from beforehand contaminated bivalves at concentrations ranging from 0.9 ± 0.1 to 20.2 ± 9 μg/g fw provided to each crayfish over the 10 days) applying a daily feeding rate equal to 3.9 ± 0.8% fw. The efficiency of U trophic transfer from clams to crayfish varied between 1 and 13% depending on the prey exposure modalities. Accumulation of U was observed in the digestive gland but also in gills, in the muscle, and in the molt of the crayfish after trophic exposure treatments. Under high-level exposure conditions, the digestive gland was the main target-organ, however a significant accumulation was also observed in the stomach. With regard to low levels of trophic exposure, accumulation of U in gills, in the stomach, and in the digestive gland was of the same order of magnitude. Longer exposure period which incorporated a crayfish molt, resulted in a decrease of trophic transfer ratio and a modified U tissue distribution

  10. Differences found in the macroinvertebrate community composition in the presence or absence of the invasive alien crayfish, Orconectes hylas

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    Freeland-Riggert, Brandye T.; Cairns, Stefan H.; Poulton, Barry C.; Riggert, Chris M.

    2016-01-01

    Introductions of alien species into aquatic ecosystems have been well documented, including invasions of crayfish species; however, little is known about the effects of these introductions on macroinvertebrate communities. The woodland crayfish (Orconectes hylas (Faxon)) has been introduced into the St. Francis River watershed in southeast Missouri and has displaced populations of native crayfish. The effects of O. hylas on macroinvertebrate community composition were investigated in a fourth-order Ozark stream at two locations, one with the presence of O. hylas and one without. Significant differences between sites and across four sampling periods and two habitats were found in five categories of benthic macroinvertebrate metrics: species richness, percent/composition, dominance/diversity, functional feeding groups, and biotic indices. In most seasons and habitat combinations, the invaded site had significantly higher relative abundance of riffle beetles (Coleoptera: Elmidae), and significantly lower Missouri biotic index values, total taxa richness, and both richness and relative abundance of midges (Diptera: Chironomidae). Overall study results indicate that some macroinvertebrate community differences due to the O. hylas invasion were not consistent between seasons and habitats, suggesting that further research on spatial and temporal habitat use and feeding ecology of Ozark crayfish species is needed to improve our understanding of the effects of these invasions on aquatic communities.

  11. The Impacts of flow alterations to crayfishes in Southeastern Oklahoma, with an emphasis on the mena crayfish (orconectes menae)

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    Brewer, Shannon K.; Dyer, Joseph J.

    2016-01-01

    Human activities can alter the environment to the point that it is unsuitable to the native species resulting in a loss of biodiversity. Ecologists understand the importance of biodiversity and the conservation of vulnerable species. Species that are narrowly endemic are considered to be particularly vulnerable because they often use specific habitats that are highly susceptible to human disturbance. The basic components of species conservation are 1) delineation of the spatial distribution of the species, 2) understanding how the species interacts with its environment, and 3) employing management strategies based on the ecology of the species. In this study, we investigated several crayfish species endemic to the Ouachita Mountains in Oklahoma and Arkansas. We established the spatial distributions (i.e., range) of the crayfish using Maximum Entropy species distribution modeling. We then investigated crayfish habitat use with quantitative sampling and a paired movement study. Finally, we evaluated the ability of crayfish to burrow under different environmental conditions in a controlled laboratory setting. Crayfish distribution at the landscape scale was largely driven by climate, geology and elevation. In general, the endemic crayfish in this study occurred above 300-m elevation where the geology was dominated by sandstone and shale, and rainfall totals were the highest compared to the rest of the study region. Our quantitative data indicated crayfish did not select for specific habitat types at the reach scale; however, crayfish appeared to continue to use shallow and dry habitat even as the streams dried. Movement by passive integrated transponder (PIT) tagged crayfish was highly variable but crayfish tended to burrow in response to drought rather than migrate to wet habitat. Controlled laboratory experiments revealed smaller substrate size (pebble) restricted crayfish burrowing more than larger substrates (cobble). We also found excess fine sediment restricted

  12. Toxicological studies of cadmium and zinc on the crayfish Orconectes virilis

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    Mirenda, R.J.

    1985-01-01

    The acute toxicities of cadmium and of zinc to the crayfish Oronectes virilis were determined. Adult, intermolt crayfish were exposed to a series of concentrations of either cadmium or zinc for a two week period. Cadmium was found to be a cumulative poison to the crayfish; LC50 values decreased from 6.1 mg Cd/I for 96 hours to 0.7 mg Cd/I for two weeks. An incipient LC50 was also estimated to be 0.0604 mg Cd/I. Zinc was found to have a relatively low toxicity to O. virilis under the present exposure conditions. Whole animal and tissue analyses for cadmium or zinc were performed on the crayfish used in the acute toxicity tests. Whole animals concentrations both for cadmium and for zinc exhibited a linear relationship to exposure concentrations (r = 0.85 and 0.87, respectively). The gills had the highest concentrations (r = 0.85 and 0.87, respectively). The gills had the highest concentrations of cadmium and zinc, and displayed a linear relationship to exposure concentrations (r = 0.82 and 0.87 respectively). The hepatopancreas displayed a plateau in metal concentrations and is probably the main storage site for both metals in the crayfish. The relationship of cadmium concentration to exposure concentration in the antennal glands also showed linearity (r = 0.65), while zinc levels reached a steady state level. All the remaining tissues analyzed exhibited a plateau in metal concentration

  13. Ultrastructural observations of target-organs of the crayfish Orconectes limosus exposed to metallic pollutants: application to uranium

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    Grasset, G.; Simon, O.; Floriani, M.

    2004-01-01

    Using electron microscopy associated with energy dispersive X-ray microanalysis (EDAXTEM), ultrastructure and elemental analysis in subcellular micro-localization can bring understanding to both metabolic cycle of a metallic pollutant and its potential effects at the subcellular scale. The approach consists in comparing both structures and micro-localization in various tissues/organs ultrathin sections (70-140 nm thickness) obtained from control organisms (i.e. not exposed to a given metal) and exposed organisms. However, the observations of ultrastructural effects of metal exposure involved robust comparison to reference subcellular and cellular organization. Consequently, preliminary developments presented in this poster have been performed from the non-contaminated freshwater crayfish Orconectes limosus (adult at inter-moult state). Studies of ultrastructural images and elemental composition of subcellular mineral deposits were carried out on target organs of uranium accumulation such as the digestive gland, the gills, the intestine and the antennal gland, organs participating in the detoxification, primary accumulation and depuration mechanisms. Observations indicated cell-specific architecture (identification of main organelles, frequency, length of cells), the range of natural variation of the cell organisation between individuals and identification of cellular types. Information will allow then to focus on these identified specific organization after metallic exposure. These ultrastructural observations performed on reference organisms constitute necessarily a first set of data for the cellular metallic effects analysis. (author)

  14. INTERACTION BETWEEN NATIVE AND ALIEN SPECIES OF CRAYFISH IN AUSTRIA: CASE STUDIES

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    PÖCKL M.

    2002-07-01

    Full Text Available In Austria, three indigenous crayfish species occur: the noble crayfish (Astacus astacus, the stone crayfish (Austropotamobius torrentium, and the white-clawed crayfish (Austropotamobius pallipes. It is not known if Astacus leptodactylus is autochthonous in the very eastern part of Austria, near the border with Hungary and Slovakia. In other parts of Austria the Turkish crayfish has been transplanted into several gravel pits and ponds. Up to now, the red swamp crayfish (Procambarus clarkii is not known to occur in the wild, but can be bought alive in fish markets, restaurants, and the aquarium trade. The Nearctic spiny-cheek crayfish (Orconectes limosus and the signal crayfish (Pacifastacus leniusculus have been introduced since the 1970s by crayfish farmers because these species are resistant to the crayfish plague fungus (Aphanomyces astaci. There are just a few populations of O. limosus, and the species is not spreading actively. However, P. leniusculus is widespread all over Austria, and was illegally introduced from one water body to another. It can be characterized as an aggressive, invasive North American species, spreading actively and acting as a vector of the crayfish plague. Unfortunately the habitat requirements of the native noble crayfish and the alien signal crayfish are nearly the same. Case studies are given in the following chapters: the first group of examples refers to water bodies where the alien signal crayfish is most probably the cause of displacement of the indigenous noble crayfish: 1 Hintersee, 2 Irrsee (« Zeller See », 3 north-western Lower Austria (« Waldviertel », 4 Merzenstein (aquacultural enterprise, 5 Neufelder See. The second group of examples refers to water bodies where alien and indigenous species are able to coexist: a the confluence of the main course of the Danube River, the Ölhafen and the Neue Donau in the southeast part of Vienna, b the Schönauer Wasser, a backwater of the Danube River downstream

  15. Characterization of a molt-inhibiting hormone (MIH) of the crayfish, Orconectes limosus, by cDNA cloning and mass spectrometric analysis.

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    Bulau, Patrick; Okuno, Atsuro; Thome, Elke; Schmitz, Tina; Peter-Katalinic, Jasna; Keller, Rainer

    2005-11-01

    The structure of the precursor of a molt-inhibiting hormone (MIH) of the American crayfish, Orconectes limosus was determined by cloning of a cDNA based on RNA from the neurosecretory perikarya of the X-organ in the eyestalk ganglia. The open reading frame includes the complete precursor sequence, consisting of a signal peptide of 29, and the MIH sequence of 77 amino acids. In addition, the mature peptide was isolated by HPLC from the neurohemal sinus gland and analyzed by ESI-MS and MALDI-TOF-MS peptide mapping. This showed that the mature peptide (Mass 8664.29 Da) consists of only 75 amino acids, having Ala75-NH2 as C-terminus. Thus, C-terminal Arg77 of the precursor is removed during processing, and Gly76 serves as an amide donor. Sequence comparison confirms this peptide as a novel member of the large family, which includes crustacean hyperglycaemic hormone (CHH), MIH and gonad (vitellogenesis)-inhibiting hormone (GIH/VIH). The lack of a CPRP (CHH-precursor related peptide) in the hormone precursor, the size and specific sequence characteristics show that Orl MIH belongs to the MIH/GIH(VIH) subgroup of this larger family. Comparison with the MIH of Procambarus clarkii, the only other MIH that has thus far been identified in freshwater crayfish, shows extremely high sequence conservation. Both MIHs differ in only one amino acid residue ( approximately 99% identity), whereas the sequence identity to several other known MIHs is between 40 and 46%.

  16. A review of ecological interactions between crayfish and fish, indigenous and introduced

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    Reynolds J.D.

    2011-05-01

    Full Text Available Crayfish (decapods and fish are both long-lived large members of freshwater communities, often functioning as keystone species. This paper reviews interactions between these, with emphasis on the European context. Native crayfish and fish are in ecological balance, which may involve mutual predation, competition and sometimes habitat disturbance. This balance is disrupted by range extensions and translocations of native fish or crayfish into exotic situations. Some fish and crayfish have been translocated globally, chiefly from North America to other continents. Non-indigenous crayfish species (NICS may impact on native fish, just as introduced fish impact on indigenous crayfish species (ICS. Competition between ICS and NICS may result in making the former susceptible to various mechanisms of interaction with fish, indigenous or introduced. In Europe, long-established NICS – signals, spiny-cheek and red swamp crayfish – may occur in greater densities than ICS; they are more tolerant and aggressive and show more interactions with fish. More recent introductions, still restricted in distribution, have not yet received enough study for their impacts to be assessed. Interactions between fish and crayfish in North and South America, Madagascar and Australasia are also explored. Mechanisms of interaction between fish and crayfish include mutual predation, competition for food and spatial resources, food-web alteration and habitat modification. Resultant changes in communities and ecosystems may be physical or biotal, and affect both ecosystem services and exploitation potential.

  17. Predicting probability of occurrence and factors affecting distribution and abundance of three Ozark endemic crayfish species at multiple spatial scales

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    Nolen, Matthew S.; Magoulick, Daniel D.; DiStefano, Robert J.; Imhoff, Emily M.; Wagner, Brian K.

    2014-01-01

    Crayfishes and other freshwater aquatic fauna are particularly at risk globally due to anthropogenic demand, manipulation and exploitation of freshwater resources and yet are often understudied. The Ozark faunal region of Missouri and Arkansas harbours a high level of aquatic biological diversity, especially in regard to endemic crayfishes. Three such endemics, Orconectes eupunctus,Orconectes marchandi and Cambarus hubbsi, are threatened by limited natural distribution and the invasions of Orconectes neglectus.

  18. Systematics and biogeography of Orconectes, subgenus Trisellescens, in the southeastern United States, a test of morphology-based classification

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    Christopher A. Taylor; Susan B. Adams; Guenter A. Schuster

    2014-01-01

    Diagnosable taxonomic units are fundamental to conservation biology and management of resources and the need for sound science in both fields is more pressing for aquatic ecosystems. Within freshwater crayfishes, the North American genus Orconectes is one of the most diverse in the World. Accurate assessments of species level relationships and species boundaries within...

  19. A review of the ever increasing threat to European crayfish from non-indigenous crayfish species

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    D.M. Holdich

    2009-01-01

    Full Text Available Non-indigenous crayfish species (NICS in Europe now outnumber indigenous crayfish species (ICS 2:1, and it has been predicted that they may dominate completely in the next few decades unless something is done to protect them. Of the ten NICS introduced at least nine have become established in areas occupied by four of the five ICS. A decline in stocks of ICS has been recorded in many countries in the face of increasing populations of NICS. Most European countries retain at least one ICS but all are under threat from habitat loss, deteriorating water quality, overfishing, climate change, and most importantly from NICS and crayfish plague. The threat to ICS is so great in some countries that “ark”sanctuary sites are being established.The three most widely-spread NICS are the North American species: Pacifastacus leniusculus, Orconectes limosus and Procambarus clarkii. These can be considered as “Old NICS”, which were introduced before 1975, compared with the “New NICS”, which were introduced after 1980, such as the North American species: Orconectes immunis, Orconectes juvenilis, Orconectes virilis, Procambarus sp. and Procambarus acutus; and the Australian species: Cherax destructor and Cherax quadricarinatus, all of which have much narrower ranges in Europe. The North American species are potentially capable of acting as vectors of crayfish plague. Outbreaks of this disease occur regularly where there are high concentrations of vectors.In addition to the NICS currently established in the wild, a further threat exists through the aquarium trade, where many American and Australian species are available via the internet and in aquarist centres. Owners of such species may discard them into the freshwater environment when they grow too big as with some Cherax spp. and Orconectes spp., or multiply too frequently as with Procambarus sp. (a parthenogenetic species. A conceptual model is presented as a possible way forward for protecting the

  20. Impacts of drought and crayfish invasion on stream ecosystem structure and function

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    Magoulick, Daniel D.

    2014-01-01

    Drought and seasonal drying can be important disturbance events in many small streams, leading to intermittent or isolated habitats. Many small streams contain crayfish populations that are often keystone or dominant species in these systems. I conducted an experiment in stream mesocosms to examine the effects of drought and potential ecological redundancy of a native and invasive crayfish species. I examined the effects of drought (drought or control) and crayfish presence (none, native crayfish Orconectes eupunctus or invasive crayfish Orconectes neglectus) on stream mesocosm structure and function (leaf breakdown, community metabolism, periphyton, sediment and chironomid densities) in a fully factorial design. Each mesocosm contained a deep and shallow section, and drought treatments had surface water present (5-cm depth) in deep sections where tiles and leaf packs were placed. Drought and crayfish presence did not interact for any response variable. Drought significantly reduced leaf breakdown, and crayfish presence significantly increased leaf breakdown. However, the native and invasive crayfish species did not differ significantly in their effects on leaf breakdown. Drought significantly reduced primary production and community respiration overall, whereas crayfish presence did not significantly affect primary production and community respiration. Neither drought nor crayfish presence significantly affected periphyton overall. However, drought significantly reduced autotrophic index (AI), and crayfish presence increased AI. Inorganic sediment and chironomid density were not affected by drought, but both were significantly reduced by crayfish presence. O. eupunctus reduced AI and sediment more than O. neglectus did. Neither drought nor crayfish species significantly affected crayfish growth or survival. Drought can have strong effects on ecosystem function, but weaker effects on benthic structure. Crayfish can have strong effects on ecosystem

  1. Different aspects of reproduction strategies in crayfish: A review

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    Yazicioglu B.

    2016-01-01

    Full Text Available Study of the reproductive strategy of crayfish species is of great importance in the current astacological world. Crayfish are among the largest freshwater invertebrates, and as keystone species, they are able to regulate the structure of the benthic fauna in the freshwaters, demonstrating different ecological strategies and life spans ranging up to 20+ years. In order to bring together the various pieces of information related to this issue, this overview of published scientific reports was conducted. The majority of crayfish species studied show sexual dimorphism, with approximately equal numbers of males and females. However, over some decades numerous observations have been made for a few species that may have different modes of reproduction, such as hermaphroditism or intersex (e.g. Cherax quadricarinatus, Samastacus spinifrons, Parastacus virilastacus and Pacifastacus leniusculus and parthenogenesis (only Procambarus fallax f. virginalis. A recent study showed a new case of parthenogenesis as apomictic parthenogenesis (only Orconectes limosus. In addition, there are many investigations into the reproduction biology of crayfish, including using eyestalk ablation or androgenic gland ablation under various lab conditions and hybridization under natural conditions (e.g. Astacus astacus X Astacus leptodactylus, Orconectes rusticus X Orconectes propinquus. There are also some chemical factors which could possibly affect the reproduction system of crayfish in the wild.

  2. Invasive crayfish in the Pacific Northwest

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    Pearl, Christopher A.; McCreary, Brome; Adams, Michael

    2011-01-01

    Invasive species directly threaten freshwater biodiversity, particularly in regions of high aquatic richness like the Pacific Northwest (PNW). Crayfish are among the most impactful of aquatic invasive species. Invasive crayfish are considered ecosystem engineers due to their ability to alter basic wetland properties, such as reducing vegetation and bank integrity and increasing turbidity. In areas where invasion is advanced, crayfish pose major economic and ecological problems. Crayfish have been widely introduced for aquaculture and can become established in a wide range of habitat conditions. They also may be spread by anglers who use them as bait. Several non-native crayfish are established in the PNW, but the extent of their invasion is not well known. At least two groups are known from scattered sites in the PNW, and both have proven problematic for native species in other parts of the world: Red swamp crayfish (Procambarus clarkii) and several members of the genus Orconectes. Both groups are native to areas of the eastern United States. Both are identified globally as invasives of high concern and appear on the Oregon Department of Fish and Wildlife's "10 Most Unwanted" and the U.S. Forest Service's "Primary Species of Concern" lists for stream systems in the PNW. Despite the presence of introduced crayfish in the PNW and their high potential for negative effects, the scope of their invasion and effects on aquatic systems are not well known. The U.S. Geological Survey (USGS), along with local groups and state agencies, is working to clarify crayfish distribution and to outline which basins may not yet be invaded. Other goals are to improve understanding of habitat associations of invasive crayfish and their potential effects on native crayfish.

  3. Effects of depth and crayfish size on predation risk and foraging profitability of a lotic crayfish

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    Flinders, C.A.; Magoulick, D.D.

    2007-01-01

    We conducted field surveys and experiments to determine whether observed distributions of crayfish among habitats were influenced by differential resource availability, foraging profitability, and predation rates and whether these factors differed with crayfish size and habitat depth. We sampled available food resources (detritus and invertebrates) and shelter as rock substrate in deep (>50 cm) and shallow (<30 cm) habitats. We used an enclosure-exclosure experiment to examine the effects of water depth and crayfish size on crayfish biomass and survival, and to determine whether these factors affected silt accrual, algal abundance (chlorophyll a [chl a]), and detritus and invertebrate biomass (g ash-free dry mass) differently from enclosures without crayfish. We conducted tethering experiments to assess predation on small (13-17 mm carapace length [CL]) and large (23-30 mm CL) Orconectes marchandi and to determine whether predation rates differed with water depth. Invertebrate biomass was significantly greater in shallow water than in deep water, whereas detritus biomass did not differ significantly between depths. Cobble was significantly more abundant in shallow than in deep water. Depth and crayfish size had a significant interactive effect on change in size of enclosed crayfish when CL was used as a measure of size but not when biomass was used as a measure of size. CL of small crayfish increased significantly more in enclosures in shallow than in deep water, but CL of large crayfish changed very little at either depth. Silt, chl a, and detritus biomass were significantly lower on tiles in large- than in small- and no-crayfish enclosures, and invertebrate biomass was significantly lower in large- than in no-crayfish enclosures. Significantly more crayfish were consumed in deep than in shallow water regardless of crayfish size. Our results suggest that predation and resource availability might influence the depth distribution of small and large crayfish. Small

  4. Identification of exotic North American crayfish in Europe by DNA barcoding

    Directory of Open Access Journals (Sweden)

    Filipová L.

    2011-05-01

    Full Text Available Several alien crayfish of North American origin have become established in Europe in recent decades, but their identification is often confusing. Our aim was to verify the taxonomic status of their European populations by DNA barcoding. We sequenced the cytochrome c oxidase subunit I (COI gene fragment of individuals representing all American crayfish known from European waters, and compared the results with reference sequences from North America. Our results confirm the morphological identification of Orconectes juvenilis from a population in eastern France, and of the marbled crayfish (Marmorkrebs, i.e., a parthenogenetic form of Procambarus fallax, from south-western Germany. Sequences of most individuals of presumed Procambarus acutus from the Netherlands were similar to American P. cf. acutus, but one was divergent, closer to a sequence of a reference individual of P. cf. zonangulus. However, divergences among three American P. cf. zonangulus samples were also high, comparable to interspecific variation within cambarid species complexes. The divergence between O. immunis from Europe and America also reached values corresponding to those observed among distinct Orconectes species. Genetic variation in the American range of these crayfish should therefore be further studied. Our study shows that DNA barcoding is useful for the rapid and accurate identification of exotic crayfish in Europe, and also provides insights into overall variation within these taxa.

  5. Effects of mining-derived metals on riffle-dwelling crayfish in southwestern Missouri and southeastern Kansas, USA

    Science.gov (United States)

    Allert, Ann L.; DiStefano, Robert J.; Schmitt, Christopher J.; Fairchild, James F.; Brumbaugh, William G.

    2012-01-01

    Riffle-dwelling crayfish populations were sampled at 16 sites in 4 tributaries of the Spring River located within the Tri-State Mining District in southwest Missouri. Crayfish density, physical habitat quality, and water quality were examined at each site to assess the ecological effects of mining-derived metals on crayfish. Metals (lead, zinc, and cadmium) were analyzed in samples of surface water, sediment, detritus, and whole crayfish. Sites were classified a posteriori into reference, mining, and downstream sites primarily based on metal concentrations in the materials analyzed. Three species of crayfish (Orconectes neglectus neglectus, O. macrus, and O. virilis) were collected during the study; however, only O. n. neglectus was collected at all sites. Mean crayfish densities were significantly lower at mining sites than at reference sites. Mean concentrations of metals were significantly correlated among the materials analyzed and were significantly greater at mining and downstream sites than at reference sites. Principal component analyses showed a separation of sites due to an inverse relationship among crayfish density, metals concentrations, and physical habitat quality variables. Sediment probable-effects quotients and surface-water toxic unit scores were significantly correlated; both indicated risk of toxicity to aquatic biota at several sites. Metals concentrations in whole crayfish at several sites exceeded concentrations known to be toxic to carnivorous wildlife. Mining-derived metals have the potential to impair ecosystem function through decreased organic matter processing and nutrient cycling in streams due to decreased crayfish densities.

  6. Effects of historical lead–zinc mining on riffle-dwelling benthic fish and crayfish in the Big River of southeastern Missouri, USA

    Science.gov (United States)

    Allert, A.L.; DiStefano, R.J.; Fairchild, J.F.; Schmitt, C.J.; McKee, M.J.; Girondo, J.A.; Brumbaugh, W.G.; May, T.W.

    2013-01-01

    The Big River (BGR) drains much of the Old Lead Belt mining district (OLB) in southeastern Missouri, USA, which was historically among the largest producers of lead–zinc (Pb–Zn) ore in the world. We sampled benthic fish and crayfish in riffle habitats at eight sites in the BGR and conducted 56-day in situ exposures to the woodland crayfish (Orconectes hylas) and golden crayfish (Orconectes luteus) in cages at four sites affected to differing degrees by mining. Densities of fish and crayfish, physical habitat and water quality, and the survival and growth of caged crayfish were examined at sites with no known upstream mining activities (i.e., reference sites) and at sites downstream of mining areas (i.e., mining and downstream sites). Lead, zinc, and cadmium were analyzed in surface and pore water, sediment, detritus, fish, crayfish, and other benthic macro-invertebrates. Metals concentrations in all materials analyzed were greater at mining and downstream sites than at reference sites. Ten species of fish and four species of crayfish were collected. Fish and crayfish densities were significantly greater at reference than mining or downstream sites, and densities were greater at downstream than mining sites. Survival of caged crayfish was significantly lower at mining sites than reference sites; downstream sites were not tested. Chronic toxic-unit scores and sediment probable effects quotients indicated significant risk of toxicity to fish and crayfish, and metals concentrations in crayfish were sufficiently high to represent a risk to wildlife at mining and downstream sites. Collectively, the results provided direct evidence that metals associated with historical mining activities in the OLB continue to affect aquatic life in the BGR.

  7. Partition of ruthenium-106 between the fresh water environment and crayfish

    International Nuclear Information System (INIS)

    Berg, G.G.; Ginsberg, E.

    1976-01-01

    Crayfish of two species, Orconectes obscurus and Cambarus robustus, were identified in West Valley, New York, in streams contaminated with radioactive wastes. 106 Ru accounted for over 90% of the gamma radioactivity in specimens collected in 1972, and had higher concentrations in the crayfish than in fish from that site. Crayfish are suggested as indicator organisms for 106 Ru. In subsequent aquarium experiments, crayfish exposed to water labeled with inorganic complexes of 106 Ru concentrated the dissolved ruthenium an average of 9 x and accumulated 50% of the equilibrium body burden in approximately 10 hr, with the bulk of the isotope bound at the surface of the exoskeleton. If food was also exposed to the labeled water, uptake was faster and high concentrations were found in the digestive gland, which showed concentration factors in excess of 25 x. Releases were slower and bimodal, with approximately 10% of body burden remaining after 1 or 2 months in repeated changes of water. Data describe the partition of 106 Ru to colloidal aggregates and organically-bound sediments, and its availability for bioconcentration. (author)

  8. A comparison of two gears for quantifying abundance of lotic-dwelling crayfish

    Science.gov (United States)

    Williams, Kristi; Brewer, Shannon K.; Ellersieck, Mark R.

    2014-01-01

    Crayfish (saddlebacked crayfish, Orconectes medius) catch was compared using a kick seine applied two different ways with a 1-m2 quadrat sampler (with known efficiency and bias in riffles) from three small streams in the Missouri Ozarks. Triplicate samples (one of each technique) were taken from two creeks and one headwater stream (n=69 sites) over a two-year period. General linear mixed models showed the number of crayfish collected using the quadrat sampler was greater than the number collected using either of the two seine techniques. However, there was no significant interaction with gear suggesting year, stream size, and channel unit type did not relate to different catches of crayfish by gear type. Variation in catch among gears was similar, as was the proportion of young-of-year individuals across samples taken with different gears or techniques. Negative binomial linear regression provided the appropriate relation between the gears which allows correction factors to be applied, if necessary, to relate catches by the kick seine to those of the quadrat sampler. The kick seine appears to be a reasonable substitute to the quadrat sampler in these shallow streams, with the advantage of ease of use and shorter time required per sample.

  9. Do environmental changes or juvenile competition act as mechanisms of species displacement in crayfishes?

    Science.gov (United States)

    Westhoff, Jacob T.; DiStefano, R.J.; Magoulick, D.D.

    2012-01-01

    The Big Creek Crayfish, Orconectes peruncus, is native to the St. Francis River drainage in Missouri, USA and is often absent where the introduced Woodland Crayfish, Orconectes hylas, has established. We performed a field experiment to determine whether effects of current abiotic conditions and interspecific competition with O. hylas were responsible for displacement of O. peruncus from parts of their former range. We examined growth and survival of juvenile male O. peruncus exposed to juvenile male O. hylas in enclosures at two sites in the former range of O. peruncus. Enclosures contained 8 (low density) or 16 individuals (high density) and had O. peruncus only (control) or both species (interspecific treatment). Juvenile O. peruncus were able to survive and grow in portions of their former range, implicating biotic versus abiotic factors in the displacement of O. peruncus. Survival rates of O. peruncus did not differ among treatments at either site. Orconectes peruncus showed significant growth in all treatments and interspecific effects were not greater than intraspecific effects on O. peruncus growth rates. High-density treatments showed significantly reduced O. peruncus growth rates compared to low-density treatments, except in Carver Creek interspecific treatments. When considered in the context of previous studies examining the effects of O. hylas on O. peruncus, results suggest that neither direct competition between juvenile males of the two species or abiotic change are responsible for the decreased range of O. peruncus. Additional research is required to determine the mechanism(s) driving the displacement of O. peruncus. ?? 2011 Springer Science+Business Media B.V.

  10. Crayfish impact desert river ecosystem function and litter-dwelling invertebrate communities through association with novel detrital resources.

    Directory of Open Access Journals (Sweden)

    Eric K Moody

    Full Text Available Shifts in plant species distributions due to global change are increasing the availability of novel resources in a variety of ecosystems worldwide. In semiarid riparian areas, hydric pioneer tree species are being replaced by drought-tolerant plant species as water availability decreases. Additionally, introduced omnivorous crayfish, which feed upon primary producers, allochthonous detritus, and benthic invertebrates, can impact communities at multiple levels through both direct and indirect effects mediated by drought-tolerant plants. We tested the impact of both virile crayfish (Orconectes virilis and litter type on benthic invertebrates and the effect of crayfish on detrital resources across a gradient of riparian vegetation drought-tolerance using field cages with leaf litter bags in the San Pedro River in Southeastern Arizona. Virile crayfish increased breakdown rate of novel drought-tolerant saltcedar (Tamarix ramosissima, but did not impact breakdown of drought-tolerant seepwillow (Baccharis salicifolia or hydric Fremont cottonwood (Populus fremontii and Gooding's willow (Salix goodingii. Effects on invertebrate diversity were observed at the litter bag scale, but no effects were found at the cage scale. Crayfish decreased alpha diversity of colonizing macroinvertebrates, but did not affect beta diversity. In contrast, the drought-tolerant litter treatment decreased beta diversity relative to hydric litter. As drought-tolerant species become more abundant in riparian zones, their litter will become a larger component of the organic matter budget of desert streams which may serve to homogenize the litter-dwelling community and support elevated populations of virile crayfish. Through impacts at multiple trophic levels, crayfish have a significant effect on desert stream ecosystems.

  11. Habitat and co-occurrence of native and invasive crayfish in the Pacific Northwest, USA

    Science.gov (United States)

    Pearl, Christopher A.; Adams, Michael J.; McCreary, Brome

    2013-01-01

    Biological invasions can have dramatic effects on freshwater ecosystems and introduced crayfish can be particularly impacting. We document crayfish distribution in three large hydrographic basins (Rogue, Umpqua, Willamette/Columbia) in the Pacific Northwest USA. We used occupancy analyses to investigate habitat relationships and evidence for displacement of native Pacifastacus leniusculus (Dana, 1852) by two invaders. We found invasive Procambarus clarkii (Girard, 1852), in 51 of 283 sites and in all three hydrographic basins. We found invasive Orconectes n. neglectus (Faxon, 1885) at 68% of sites in the Rogue basin and provide first documentation of their broad distribution in the Umpqua basin. We found P. clarkii in both lentic and lotic habitats, and it was positively associated with manmade sites. P. leniusculus was positively associated with lotic habitats and negatively related to manmade sites. In the Rogue and Umpqua basins, O. n. neglectus and P. leniusculus were similar in their habitat associations. We did not find a negative relationship in site occupancy between O. n. neglectus and P. leniusculus. Our data suggest that P. clarkii has potential to locally displace P. leniusculus. There is still time for preventive measures to limit the spread of the invasive crayfish in this region.

  12. ORCONECTES LIMOSUS COLONISES NEW AREAS FAST ALONG THE DANUBE IN HUNGARY

    Directory of Open Access Journals (Sweden)

    PUKY M.

    2006-01-01

    Full Text Available Introduced species are one of the most important anthropogenic impacts on freshwater ecosystems with many direct and indirect effects on native taxa. Among other invasive groups, such as plants, mussels and fish, several alien Decapoda species have also spread successfully in Europe in the last 110 years. In Hungary three native (Astacus astacus, Astacus leptodactylus, Austropotamobius torrentium and three alien Decapoda species, namely Orconectes limosus, Pacifastacus leniusculus and Eriocheir sinensis are known to be present. O. limosus, which had been tried for use in crayfish farming in the 1950s, was the first to occur in the country’s natural waters. Initially it was found in the Danube at river km 1,653 at Budapest in 1985. Since then, it has been spreading fast and populations have reached high abundances. By 1998, it was already in the Gemenc section of the river colonising five 50 km × 50 km UTM squares. In the early 2000s it was also found at Mohács (and further downstream in Croatia, in canals in the Great Hungarian Plain and in the River Ipoly, which added three new 50 km × 50 km UTM squares to its previously known distribution area in the Carpathian Basin. On the basis of the available records from the past 20 years, the downstream colonisation speed of this decapod was calculated to be more than 13 km yr–1, but if its presence at Kopácsi rét/Kopacki rit in Croatia is also taken into consideration, it is over 16 km yr–1. It is unknown, however, how much this process was helped by deliberate introductions, if at all. Besides the main watercourse of Hungary, O. limosus is also common in its lowland tributaries and spreading towards Lake Balaton along the Sió canal. However, it has not been recorded entering mountain streams in the Danube Bend, where A. torrentium lives, which is important for the conservation of that native species. If O. limosus spreads with the same speed and distribution pattern in the Carpathian Basin

  13. The Sensitivity of the Crayfish Reward System to Mammalian Drugs of Abuse.

    Science.gov (United States)

    Shipley, Adam T; Imeh-Nathaniel, Adebobola; Orfanakos, Vasiliki B; Wormack, Leah N; Huber, Robert; Nathaniel, Thomas I

    2017-01-01

    The idea that addiction occurs when the brain is not able to differentiate whether specific reward circuits were triggered by adaptive natural rewards or falsely activated by addictive drugs exist in several models of drug addiction. The suitability of crayfish ( Orconectes rusticus ) for drug addiction research arises from developmental variation of growth, life span, reproduction, behavior and some quantitative traits, especially among isogenic mates reared in the same environment. This broad spectrum of traits makes it easier to analyze the effect of mammalian drugs of abuse in shaping behavioral phenotype. Moreover, the broad behavioral repertoire allows the investigation of self-reinforcing circuitries involving appetitive and exploratory motor behavior, while the step-wise alteration of the phenotype by metamorphosis allows accurate longitudinal analysis of different behavioral states. This paper reviews a series of recent experimental findings that evidence the suitability of crayfish as an invertebrate model system for the study of drug addiction. Results from these studies reveal that unconditioned exposure to mammalian drugs of abuse produces a variety of stereotyped behaviors. Moreover, if presented in the context of novelty, drugs directly stimulate exploration and appetitive motor patterns along with molecular processes for drug conditioned reward. Findings from these studies indicate the existence of drug sensitive circuitry in crayfish that facilitates exploratory behavior and appetitive motor patterns via increased incentive salience of environmental stimuli or by increasing exploratory motor patterns. This work demonstrates the potential of crayfish as a model system for research into the neural mechanisms of addiction, by contributing an evolutionary, comparative context to our understanding of natural reward as an important life-sustaining process.

  14. The Sensitivity of the Crayfish Reward System to Mammalian Drugs of Abuse

    Directory of Open Access Journals (Sweden)

    Adam T. Shipley

    2017-12-01

    Full Text Available The idea that addiction occurs when the brain is not able to differentiate whether specific reward circuits were triggered by adaptive natural rewards or falsely activated by addictive drugs exist in several models of drug addiction. The suitability of crayfish (Orconectes rusticus for drug addiction research arises from developmental variation of growth, life span, reproduction, behavior and some quantitative traits, especially among isogenic mates reared in the same environment. This broad spectrum of traits makes it easier to analyze the effect of mammalian drugs of abuse in shaping behavioral phenotype. Moreover, the broad behavioral repertoire allows the investigation of self-reinforcing circuitries involving appetitive and exploratory motor behavior, while the step-wise alteration of the phenotype by metamorphosis allows accurate longitudinal analysis of different behavioral states. This paper reviews a series of recent experimental findings that evidence the suitability of crayfish as an invertebrate model system for the study of drug addiction. Results from these studies reveal that unconditioned exposure to mammalian drugs of abuse produces a variety of stereotyped behaviors. Moreover, if presented in the context of novelty, drugs directly stimulate exploration and appetitive motor patterns along with molecular processes for drug conditioned reward. Findings from these studies indicate the existence of drug sensitive circuitry in crayfish that facilitates exploratory behavior and appetitive motor patterns via increased incentive salience of environmental stimuli or by increasing exploratory motor patterns. This work demonstrates the potential of crayfish as a model system for research into the neural mechanisms of addiction, by contributing an evolutionary, comparative context to our understanding of natural reward as an important life-sustaining process.

  15. Concentrations of elements in fish fillets, fish muscle plugs, and crayfish from the 2007 Missouri Department of Conservation General Contaminant Monitoring Program

    Science.gov (United States)

    May, Thomas W.; Walther, Michael J.; Brumbaugh, William G.; McKee, Michael J.

    2009-01-01

    This report presents the results of a contaminant monitoring survey conducted annually by the Missouri Department of Conservation to examine the levels of selected elemental contaminants in fish fillets, fish muscle plugs, and crayfish. Fillets of channel catfish (Ictalurus punctatus), bass (Micropterus salmoides, Micropterus dolomieu, Morone chrysops), walleye (Sander vitreus), common carp (Cyprinus carpio), lake sturgeon (Acipenser fulvescens), northern hog sucker (Hypentelium nigricans), and rainbow trout (Oncorhynchus mykiss) were collected from 21 sites as part of the Department's Fish Contaminant Monitoring Program. Long-pincered crayfish (Orconectes longidigitus) were collected from one site to assess trophic transfer of metals to fish. Fish muscle plugs were collected from smallmouth bass (Micropterus dolomieu) at two different locations from one site.

  16. Method for aquatic multiple species toxicant testing: acute toxicity of 10 chemicals to 5 vertebrates and 2 invertebrates. [Pimephales promelas; Carassius auratus; Ictalurus punctatus; Lepomis macrochirus; Salmo gairdneri; Orconectes immunis; Aplexa hypnorum

    Energy Technology Data Exchange (ETDEWEB)

    Phipps, G.L.; Holcombe, G.W.

    1985-01-01

    A method was developed to simultaneously ascertain 96 h LC/sub 50/ values for seven freshwater species in a single flow through test with measured concentrations. It allows interspecific comparisons, easy determination of the most sensitive species, and cuts cost of labor, materials and chemical analysis for measured concentration tests. Species tested included fathead minnows Pimephales promelas, goldfish Carassius auratus, channel catfish Ictalurus punctatus, bluegill Lepomis macrochirus, rainbow trout Salmo gairdneri, crayfish Orconectes immunis and snails Aplexa hypnorum. Compounds tested were pentachlorophenol, 2-chloroethanol, 2,4-pentanedione, hexachloroethane, ..cap alpha..-bromo-2',5'-dimethoxyacetophenone, benzaldehyde, 1,3-dichloro-4,6-dinitro-benzene, dursban, sevin and cadmium chloride. The LC/sub 50/ values from these multiple species tests compared favourably with those determined using single species tests at this laboratory, usually within 20%.

  17. Effect of uranium chronic exposure on the moult in crayfish

    International Nuclear Information System (INIS)

    Simon, O.; Camilleri, V.; Garnier-Laplace, J.

    2004-01-01

    Throughout any ecological risk assessment, one can try to establish a link between pollutant in the ecosystem and adverse biological effects. A number of methodological approaches are based on the development of the use of bio-markers such as the enzyme activity measurements (biotransformation enzymes, antioxidant enzymes) and/or bioaccumulation markers (metal in target-organs). These data allow obtaining an early-warning signal of exposure and potential involved effects and help risk management. However, the effects at higher hierarchical levels (organism or population) are not frequently considered because they tend to occur after longer exposure periods. On the basis of previous results obtained to quantify uranium biokinetics in the crayfish Orconectes limosus and to understand the influence of the exposure pathway, a chronic exposure experiment was performed for 100 days at an environmentally relevant uranium concentration in water (low level concentration ranging from?? to 100 nM). The main effect studied was focused on the moult; moulted animals being the most sensitive to pollutants. Effects on the moult process were assessed in terms of occurrence, delay, and success. Preliminary results that indicated no induction of the moult by U exposure and better survival rate to uranium exposure must be confirmed. Simultaneously, both enzymatic bio-markers of effect quantifying the oxidative status (catalase, superoxide dismutase and glutathione peroxidases) and markers of exposure (uranium distribution at organs and cellular levels and MET observations) were studied. Results obtained from complementary experiments on the uranium fluxes all over moult states were used to discuss the link between bio-markers responses and observed effects on the moult. (author)

  18. Effect of uranium chronic exposure on the moult in crayfish

    Energy Technology Data Exchange (ETDEWEB)

    Simon, O.; Camilleri, V.; Garnier-Laplace, J. [CEA Cadarache (DEI/SECRE/LRE), Laboratory of Radioecology and Ecotoxicology, Institute for Radioprotection and Nuclear Safety, 13 - Saint-Paul-lez-Durance (France)

    2004-07-01

    Throughout any ecological risk assessment, one can try to establish a link between pollutant in the ecosystem and adverse biological effects. A number of methodological approaches are based on the development of the use of bio-markers such as the enzyme activity measurements (biotransformation enzymes, antioxidant enzymes) and/or bioaccumulation markers (metal in target-organs). These data allow obtaining an early-warning signal of exposure and potential involved effects and help risk management. However, the effects at higher hierarchical levels (organism or population) are not frequently considered because they tend to occur after longer exposure periods. On the basis of previous results obtained to quantify uranium biokinetics in the crayfish Orconectes limosus and to understand the influence of the exposure pathway, a chronic exposure experiment was performed for 100 days at an environmentally relevant uranium concentration in water (low level concentration ranging from?? to 100 nM). The main effect studied was focused on the moult; moulted animals being the most sensitive to pollutants. Effects on the moult process were assessed in terms of occurrence, delay, and success. Preliminary results that indicated no induction of the moult by U exposure and better survival rate to uranium exposure must be confirmed. Simultaneously, both enzymatic bio-markers of effect quantifying the oxidative status (catalase, superoxide dismutase and glutathione peroxidases) and markers of exposure (uranium distribution at organs and cellular levels and MET observations) were studied. Results obtained from complementary experiments on the uranium fluxes all over moult states were used to discuss the link between bio-markers responses and observed effects on the moult. (author)

  19. REINTRODUCTION OF NOBLE CRAYFISH ASTACUS ASTACUS AFTER CRAYFISH PLAGUE IN NORWAY

    Directory of Open Access Journals (Sweden)

    TAUGBØL T.

    2004-01-01

    Full Text Available The Glomma and Halden watercourses in Norway were hit by crayfish plague in 1987 and 1989. Reintroduction of the noble crayfish started in 1989 in the Glomma and in 1995 in the Halden watercourse. Norway has especially good conditions for reintroduction of the native crayfish after crayfish plague, as there is no alien plague-carrying crayfish species in the country. In the Glomma watercourse, approx. 15 000 adult crayfish and 10 000 juveniles have been stocked while in the Halden watercourse the figures are 19 000 adults and 26 500 juveniles. All stocking sites were previously regarded as very good crayfish localities. Four years after stocking, natural recruitment was recorded at all adult crayfish stocking sites in the Glomma watercourse and at most sites in the Halden watercourse. Current crayfish density is, however, much lower than pre-plague densities even at the sites where population development has been in progress for more than 10 years. Extensive post-stocking movements were recorded among adult crayfish. Some sites seemed more suitable for settling, resulting in a great variation in CPUE between the different test-fishing sites. Juveniles seem more appropriate as stocking material if the goal is to re-establish a population in a particular area, due to their stationary behaviour, which seems to remain as they grow larger.

  20. Garden ponds as potential introduction pathway of ornamental crayfish

    Directory of Open Access Journals (Sweden)

    Patoka J.

    2014-01-01

    Full Text Available The private stocking of ornamental crayfish in garden ponds was discussed in previous studies, but there is a lack of detailed analysis for better understanding of this introduction pathway. The Czech Republic is one of leading EU countries in trade with ornamental crayfish and private garden ponds are popular among people. The crayfish keepers in the country were interviewed by self-administered questionnaire to gather data about principal characteristics of the keepers and detailed information about crayfish breeding that are of interest for conservation managers. Besides of releasing crayfish into garden ponds, alarming illegal behavior such as releasing of juvenile crayfish into the wild, and capturing of indigenous crayfish from wild populations, were registered. Therefore focusing on public education to increase awareness of possible unwanted consequences of crayfish release and introduction of an obligation to inform customers about hazardousness of non-indigenous crayfish species for retailers and wholesalers is recommended.

  1. Field and laboratory tests on acute toxicity of cadmium to freshwater crayfish

    Energy Technology Data Exchange (ETDEWEB)

    1986-09-01

    Environmental regulatory standards for cadmium (EPA 1980), like those for most pollutants, are based on acute, laboratory toxicity tests of single species. Such tests can be conducted rapidly and inexpensively in comparison to acute or chronic field studies, but their validity has often been questioned. Laboratory-based criteria are subject to two criticisms: (1) chemical and physical conditions differ greatly in degree and variability from laboratory to field, and (2) species are not isolated, but live in an ecosystem of interacting taxa and biofeedback. To investigate the validity of basing field toxicity standards on laboratory data, the authors subjected the freshwater crayfish Orconectes immunis for 96 h to various levels of cadmium in laboratory aquaria and experimental ponds. The study was designed to evaluate in part the first criticism of lab-based criteria. The studies were conducted concurrently with similar short-term experiments on the fathead minnow, Pimephales promelas, and coincided with studies of chronic cadmium stress on fathead minnows in experimental ponds.

  2. Freshwater crayfish invasions in South Africa: past, present and ...

    African Journals Online (AJOL)

    Freshwater crayfish invasions have been studied around the world, but less so in Africa, a continent devoid of native freshwater crayfish. The present study reviews historical and current information on alien freshwater crayfish species introduced into South Africa and aims to indicate which areas are at risk from invasion.

  3. The influence of coarse-scale environmental features on current and predicted future distributions of narrow-range endemic crayfish populations

    Science.gov (United States)

    Dyer, Joseph J.; Brewer, Shannon K.; Worthington, Thomas A.; Bergey, Elizabeth A.

    2013-01-01

    1.A major limitation to effective management of narrow-range crayfish populations is the paucity of information on the spatial distribution of crayfish species and a general understanding of the interacting environmental variables that drive current and future potential distributional patterns. 2.Maximum Entropy Species Distribution Modeling Software (MaxEnt) was used to predict the current and future potential distributions of four endemic crayfish species in the Ouachita Mountains. Current distributions were modelled using climate, geology, soils, land use, landform and flow variables thought to be important to lotic crayfish. Potential changes in the distribution were forecast by using models trained on current conditions and projecting onto the landscape predicted under climate-change scenarios. 3.The modelled distribution of the four species closely resembled the perceived distribution of each species but also predicted populations in streams and catchments where they had not previously been collected. Soils, elevation and winter precipitation and temperature most strongly related to current distributions and represented 6587% of the predictive power of the models. Model accuracy was high for all models, and model predictions of new populations were verified through additional field sampling. 4.Current models created using two spatial resolutions (1 and 4.5km2) showed that fine-resolution data more accurately represented current distributions. For three of the four species, the 1-km2 resolution models resulted in more conservative predictions. However, the modelled distributional extent of Orconectes leptogonopodus was similar regardless of data resolution. Field validations indicated 1-km2 resolution models were more accurate than 4.5-km2 resolution models. 5.Future projected (4.5-km2 resolution models) model distributions indicated three of the four endemic species would have truncated ranges with low occurrence probabilities under the low-emission scenario

  4. [A new method of therapy for branchiobdellosis in crayfish].

    Science.gov (United States)

    Lohniský, K

    1979-02-01

    Crayfish (Astacus fluviatilis Fabricius, 1793) were treated three times with a bath of diluted ammonia water and proflavine for four and six minutes at a temperature of 18 degrees C to get rid of the ectoparasitic worms of Branchiobdella parasita Henle, 1835; the hatching ability of the Branchiobdella parasita eggs was stopped after the treatment. No lethal effect of the bath on the crayfish of 5 to 14 cm was observed, the lethal effect on the young crayfish borne on the uropods of the female crayfish cannot be eliminated: during the baths the young crayfish died (the death rate was approximately 6% of the average fertility of crayfish); the young crayfish may have been damaged during the treatment operations with the crayfish. The bath of diluted ammonia water and proflavine may be recommended for the treatment of branchiobdellosis in crayfish to be planted, or after several-hour storage of crayfish supplied to the market. One replication of the above cycle is sufficient according to the results obtained. The ammonia content in the ammonia water depends also on the duration of storage and on the storage temperature--it can drop during the storage. Therefore the ammonia water should be used as soon as possible after the despatchment from the place of production; the ammonia content should be determined by means of titration before preparing the bath, and according to this content the dilution ratio should be adjusted.

  5. Status and management of noble crayfish Astacus astacus in Estonia

    Directory of Open Access Journals (Sweden)

    T. Paaver

    2009-01-01

    Full Text Available Noble crayfish Astacus astacus (L. is an indigenous and the only crayfish species in Estonia. It is potentially endangered by invasion of alien species, diseases and habitat deterioration but does not have legal protected status and is fished only for recreational purpose. Crayfish Working Group of Ministry of Environment and Department of Aquaculture of the Estonian University of Life Sciences have developed crayfish conservation and management plan. Since 1994 standardized test fishing with traps (which catch only crayfish over 7 cm TL has been carried out and database of these fishings shows, that crayfish is dwelling in more than 255 sites in the lakes, rivers, streams, artificial reservoirs. In 52% of monitored sites populations are weak, catch per trap night is below 1 specimen. Exceptionally rich is the stock on the island Saaremaa, where in 59% of populations catch per trap night is over 4 and can reach 50. Licensed recreational catch is allowed in regions, where monitoring data show good status of crayfish stock. It is not allowed to sell the crayfish caught on recreational license. Crayfishing season is limited with August, size limit in recreational fishery is 11 cm TL. There are 10 operating crayfish farms and 15 are under construction. The farms produce yearly around 1000 kg of commercial size crayfish for export to Finland. Over 200000 juveniles are produced for restocking yearly. Restocking projects e.g. restoration of populations, which have been lost because of plague have been successful. The main threat factor is crayfish plague. In 2006–2007 it destroyed the stock of crayfish farms of companies Veteko, Pähkla, Astacus and wild population of Põduste river on the island Saaremaa.

  6. Comparing macrophyte herbivory by introduced Louisiana crayfish ...

    African Journals Online (AJOL)

    The omnivorous Louisiana crayfish, Procambarus clarkii, has caused significant changes to macrophyte communities worldwide and may have similar negative effects in Kenya if used as a biological control agent for snails harbouring human schistosomes. Here we examine how herbivory by the introduced Louisiana ...

  7. Distribution of crayfish species in Hungarian waters

    NARCIS (Netherlands)

    Mercédesz, Ludányi; Peeters, E.T.H.M.; Kiss, B.; Roessink, I.

    2016-01-01

    Three native crayfish species, i.e.~Astacus astacus, Astacus leptodactylus and Austropotamobius torrentium, occur in Hungary. Lately, however, non-indigenous crustaceans have also invaded the country Their most recent distribution and impact on the occurrences of the native species is not clear.

  8. Exponential increase of signal crayfish in running waters in Sweden – due to illegal introductions?

    Directory of Open Access Journals (Sweden)

    Bohman P.

    2011-07-01

    Full Text Available Sweden has only one indigenous species of crayfish, the noble crayfish (Astacus astacus, Fabricius. There has been a steady decline of noble crayfish populations in Sweden since 1907, mainly due to the crayfish plague. To substitute the noble crayfish fishery lost, the Swedish government launched a large-scale introduction of the signal crayfish (Pacifastacus leniusculus Dana. Today, the signal crayfish is regarded as a chronic carrier of the crayfish plague, and an expansion of the species may seriously threaten the noble crayfish. This paper examines the decrease of noble crayfish populations, and the concurrent expansion of signal crayfish in running waters. Data from the Swedish Electrofishing RegiSter (SERS was used. We found that in 1980–1984 the noble crayfish occurred in 4.5% of the studied river sections. In 2008–2009 the occurrences had decreased to 1.9%. In contrast, the signal crayfish had increased in occurrence, from 0.2% (1980–1984 to 11.8% in (2008–2009. We studied the number of stocking permits for signal crayfish introductions, and the available signal crayfish population from the open fishery in Lake Vättern, as possible causes of this expansion. A negative correlation between stocking permits and increased occurrence in streams, and a positive correlation between the availability of crayfish in Lake Vättern and the occurrence in streams was found. This suggests that the expansion of signal crayfish may be due to illegal introductions, further endangering the endemic noble crayfish.

  9. SHELTER COMPETITION BETWEEN TWO INVASIVE CRAYFISH SPECIES: A LABORATORY STUDY

    Directory of Open Access Journals (Sweden)

    ALONSO F.

    2006-01-01

    Full Text Available Alien crayfishes represent a common threat to aquatic ecosystems. Their spread in Europe is leading to more frequent contacts between different invasive species populations. Shelter can be an important factor in the resulting interactions. A laboratory experiment was designed to analyse the competition for shelter in similarly sized males of two species that show an invasive behaviour in Spain, Pacifastacus leniusculus and Procambarus clarkii. We carried out 24 heterospecific, six-hour trials, with 30 min behavioural observations per hour. Most often, red swamp crayfish were both the first (70.8% and the long-term winner (62.5%. Usually, the long-term winner was the first winner. Whenever shelter was occupied, a passive behaviour by unsheltered individuals was more frequent in signal crayfish than in red swamp crayfish. When both were unsheltered, signal crayfish displayed more often a passive behaviour. Although the observed behaviour might be explained as the result of dominance by the red swamp crayfish over the signal crayfish, shelter availability and class, as well as different growth patterns and population size structures, could change the intensity and the outcome of the encounters in the wild, where signal crayfish usually reach larger sizes than red swamp crayfish.

  10. Monitoring of noble, signal and narrow-clawed crayfish using environmental DNA from freshwater samples

    DEFF Research Database (Denmark)

    Agersnap, Sune; Larsen, William Brenner; Knudsen, Steen Wilhelm

    2017-01-01

    human assisted expansion of non-indigenous signal crayfish Pacifastacus leniusculus that carry and transmit the crayfish plague pathogen. In Denmark, also the non-indigenous narrow-clawed crayfish Astacus leptodactylus has expanded due to anthropogenic activities. Knowledge about crayfish distribution...

  11. A new ostracod (Entocytheridae, Notocytherinae) on New Guinea crayfish1)

    NARCIS (Netherlands)

    Hart, D.G.; Hart, C.W.

    1970-01-01

    In 1967 we examined the crayfish collections in the Rijksmuseum van Natuurlijke Historie, Leiden, to determine if the crayfishes collected in New Guinea in 1954 by Dr. L. B. Holthuis, Dr. L. D. Brongersma, and Dr. M. Boeseman (Boeseman, 1963) were hosts to commensal ostracods. Of the collections

  12. Parasites of crayfish ( P. clarki ) and lobsters ( Macrobrachium ...

    African Journals Online (AJOL)

    Studies on parasites of crayfish and lobsters as indicators of metal pollution in Great Kwa River, Nigeria was evaluated using appropriate instruments for determination of Physicochemical parameters and detection of metals. Formol ether centrifugation method was used for isolation of parasites. A total of 150 crayfish and ...

  13. MINIMISING LOSS OF CRAYFISH AND HABITATDURING WORKS ON WATERCOURSES

    Directory of Open Access Journals (Sweden)

    PEAY S.

    2003-04-01

    Full Text Available Works in watercourses with white-clawed crayfish Austropotamobius pallipes cause temporary or permanent loss of habitat and crayfish. Past modifications can also leave waterbodies unfavourable for crayfish, but sometimes there is scope to improve them. Mitigation measures can reduce the impact and reinstate or even improve habitat. Various case studies show measures used during engineering works and some of the problems. Good planning and supervision are vital. The big issues at river and catchment scales (non-indigenous crayfish, disease, water quality and landuse may be higher priorities than provision of habitat at site or reach level; e.g. fencing in pastures improves riparian areas for crayfish and other species. If necessary, there are various options for natural and artificial refuges, but their success depends on flow characteristics, substrate and accessibility. Microhabitat can make the difference between success and failure.

  14. Acute toxicity of chlorantraniliprole to non-target crayfish (Procambarus clarkii) associated with rice-crayfish cropping systems.

    Science.gov (United States)

    Barbee, Gary C; McClain, W Ray; Lanka, Srinivas K; Stout, Michael J

    2010-09-01

    Chlorantraniliprole, a novel anthranilic diamide insecticide, was recently introduced into the United States where rice-crayfish crop rotations are practiced to control rice water weevil (Lissorhoptrus oryzophilus Kuschel) infestations. Chlorantraniliprole has high margins of mammalian safety and excellent insecticidal efficacy, but its toxicity to non-target crayfish is uncertain. In this study, the acute toxicity of chlorantraniliprole to the red swamp crayfish Procambarus clarkii Girard was determined using aquatic and feeding assays. The aquatic 96 h median lethal toxicity (LC(50)) data indicate that technical-grade chlorantraniliprole is highly toxic (US EPA category) to crayfish with an LC(50) of 951 microg L(-1) (95% CL = 741-1118 microg L(-1)). A no observed effect concentration (NOEC) of 480 microg L(-1) was recorded. Neither the 36 day chronic feeding study, where crayfish fed on chlorantraniliprole-treated rice seed in aquaria, nor the 144 h acute feeding test, where crayfish fed on rice seeds treated with chlorantraniliprole, produced mortality or abnormal behavior. Chlorantraniliprole is three orders of magnitude less acutely toxic to P. clarkii than lambda-cyhalothrin and etofenprox, two pyrethroid insecticides also used in rice, and is less likely to cause acute crayfish toxicity in rice pond ecosystems. Based on acute toxicity data, the use of chlorantraniliprole should be more compatible with rice-crayfish crop rotations than pyrethroids. (c) 2010 Society of Chemical Industry.

  15. Practical disinfection chemicals for fishing and crayfishing gear against crayfish plague transfer

    Directory of Open Access Journals (Sweden)

    Jussila J.

    2014-01-01

    Full Text Available We tested four commercial disinfectants against crayfish plague (Aphanomyces astaci spores in both aquatic solutions and with material mimicking fishing and crayfishing gear, e.g. traps, ropes, mesh, etc. The tested disinfectants were Proxitane®5:14, Proxitane®12:20, Wofasteril®E400, Virkon®S and hydrogen peroxide. The effects of the chemicals were initially tested in liquid zoospore cultures and the effective concentrations were then further tested using clean and dirty model materials (PP sheet, nylon rope, cotton fabric contaminated with A. astaci spore solutions. The disinfectants effective against infective crayfish plague spores with both clean and dirty model materials were Proxinate®5:14 (effective concentration was 30 mg·L-1 of PAA and Virkon®S (3 g·L-1, while Proxinate®12:20 (10 mg·L-1 of PAA and Wofasteril®E400 (30 mg·L-1 of PAA worked only with clean model materials. Hydrogen peroxide was not effective in the tested concentrations and conditions. Based on the results, the disinfectants most suitable for the fishing and crayfishing gear disinfection would be Proxitane®5:14 and Virkon®S, with the condition that all the gear should be thoroughly cleaned of organic matter to ensure inactivation of A. astaci spores.

  16. DISTRIBUTION OF CRAYFISH IN EUROPE AND SOME ADJOINING COUNTRIES

    Directory of Open Access Journals (Sweden)

    HOLDICH D. M.

    2002-07-01

    Full Text Available The distribution of crayfish in Europe is examined using information from a variety of sources mainly for the last two decades. All European countries have at least one indigenous crayfish species (ICS, many with large stocks, and most countries in Western Europe have at least one non-indigenous crayfish species (NICS. Some species termed indigenous in certain countries may have been introduced in relatively recent times. However, the meaning of the term indigenous (native varies between countries. NICS continue to expand their ranges and present a continued threat to ICS through competition and transmission of diseases, notably crayfish plague. The current high level of interest in crayfish means that many countries are monitoring their crayfish situation and, where necessary, taking steps to renew stocks of threatened indigenous species, some of which are apparently on the verge of extinction. A more regular monitoring programme for European crayfish as a whole is needed if the demise of indigenous species is to be prevented.

  17. A synthetic phylogeny of freshwater crayfish: insights for conservation

    Science.gov (United States)

    Owen, Christopher L.; Bracken-Grissom, Heather; Stern, David; Crandall, Keith A.

    2015-01-01

    Phylogenetic systematics is heading for a renaissance where we shift from considering our phylogenetic estimates as a static image in a published paper and taxonomies as a hardcopy checklist to treating both the phylogenetic estimate and dynamic taxonomies as metadata for further analyses. The Open Tree of Life project (opentreeoflife.org) is developing synthesis tools for harnessing the power of phylogenetic inference and robust taxonomy to develop a synthetic tree of life. We capitalize on this approach to estimate a synthesis tree for the freshwater crayfish. The crayfish make an exceptional group to demonstrate the utility of the synthesis approach, as there recently have been a number of phylogenetic studies on the crayfishes along with a robust underlying taxonomic framework. Importantly, the crayfish have also been extensively assessed by an IUCN Red List team and therefore have accurate and up-to-date area and conservation status data available for analysis within a phylogenetic context. Here, we develop a synthesis phylogeny for the world's freshwater crayfish and examine the phylogenetic distribution of threat. We also estimate a molecular phylogeny based on all available GenBank crayfish sequences and use this tree to estimate divergence times and test for divergence rate variation. Finally, we conduct EDGE and HEDGE analyses and identify a number of species of freshwater crayfish of highest priority in conservation efforts. PMID:25561670

  18. Comparative analysis of crayfish marketing in selected markets of ...

    African Journals Online (AJOL)

    Comparative analysis of crayfish marketing in selected markets of Akwa Ibom and Abia States, Nigeria. ... It specifically looked at market integration, costs and return, marketing margin, marketing ... EMAIL FULL TEXT EMAIL FULL TEXT

  19. Visual shape recognition in crayfish as revealed by habituation.

    Directory of Open Access Journals (Sweden)

    Cinzia Chiandetti

    2017-08-01

    Full Text Available To cope with the everyday challenges that they encounter in their evolutionary niche, crayfish are considered to rely mainly on chemical information or, alternatively, on tactile information, but not much on vision. Hence, research has focused on chemical communication, whereas crayfish visual abilities remain poorly understood and investigated. To fill in this gap, we tested whether crayfish (Procambarus clarkii can distinguish between two different visual shapes matched in terms of luminance. To this aim, we measured both the habituation response to a repeated presentation of a given shape, a downright Y, and the response recovery when a novel shape was presented. The novel shape could be either a Möbius or the same Y-shape but upright rotated. Our results demonstrate that, after habituation to the downright Y, crayfish showed a significantly higher response recovery to the Möbius as compared to the upright rotated Y. Hence, besides relying on chemo-haptic information, we found that crayfish can use sight alone to discriminate between different abstract geometrical shapes when macroscopically different. Failure to discriminate between the downright Y and its inversion or a generalization from the presence of a shape with three points creating a simple category, are both likely parsimonious explanations that should be investigated systematically in further studies. A future challenge will be understanding whether crayfish are capable of generalized shape recognition.

  20. Habitat associations of three crayfish endemic to the Ouachita Mountain Ecoregion

    Science.gov (United States)

    Dyer, Joseph J.; Brewer, Shannon K.

    2018-01-01

    Many crayfish are of conservation concern because of their use of unique habitats and often narrow ranges. In this study, we determined fine-scale habitat use by 3 crayfishes that are endemic to the Ouachita Mountains, in Oklahoma and Arkansas. We sampled Faxonius menae (Mena Crayfish), F. leptogonopodus (Little River Creek Crayfish), and Fallicambarus tenuis (Ouachita Mountain Crayfish) from wet and dry erosional channel units of 29 reaches within the Little River catchment. We compared channel-unit and microhabitat selection for each species. Crayfish of all species and life stages selected erosional channel units more often than depositional units, even though these sites were often dry. Accordingly, crayfish at all life stages typically selected the shallowest available microhabitats. Adult crayfish of all species and juvenile Little River Creek Crayfish selected patches of coarse substrate, and all crayfish tended to use the lowest amount of bedrock available. In general, we showed that these endemic crayfish used erosional channel units of streams, even when the channel units were dry. Conservation efforts that protect erosional channel units and mitigate actions that cause channel downcutting to bedrock would benefit these crayfish, particularly during harsh, summer drying periods.

  1. The potential for using red claw crayfish and hybrid African catfish as ...

    African Journals Online (AJOL)

    The potential of red claw crayfish and hybrid African catfish (Clarias gariepinus and Clarias ngamensis) as predators for Schistosoma host snails was evaluated in 2014 by monitoring the consumption of snails by crayfish and catfish in experimental tanks over time under laboratory conditions. After 15 days, both crayfish and ...

  2. Expansion of the marbled crayfish in Slovakia: beginning of an invasion in the Danube catchment?

    Directory of Open Access Journals (Sweden)

    Boris Lipták

    2016-01-01

    Full Text Available The marbled crayfish, Procambarus fallax f. virginalis, is a taxon widely available in the aquarium pet trade, which has been introduced to open waters in several European countries and in Madagascar. Recent studies confirmed this parthenogenetically reproducing crayfish as a high-risk invasive species, and vector of the crayfish plague pathogen, Aphanomyces astaci. It has been first discovered in Slovakia in 2010, but the status of the local population was not studied since then. Due to enlarged sampling area around the first report and one locality, where we presupposed the crayfish occurrence, we identified new marbled crayfish populations. Here, we report presence of three newly established marbled crayfish populations in Slovakia. Two populations are located critically close to the Váh River, a major tributary of the Danube River; one of them being directly connected to the Váh River via a side channel during occasional floods. The third established marbled crayfish population was found at the mouth of a thermal stream flowing into the Nitra River, a tributary of the Váh River. In this stream, crayfish coexist with other exotic fish and gastropod species of aquarium origin. We presume that the reported localities may serve as a source for further expansion of the marbled crayfish in the mid-part of the Danube catchment. Floods, active dispersal (including overland, passive dispersal by zoochory or anthropogenic translocations are among the major drivers facilitating the marbled crayfish colonization. We have not detected the crayfish plague pathogen in any of the studied populations. However, if spreading further, the marbled crayfish will encounter established populations of crayfish plague carriers in the Danube River, in which case they may acquire the pathogen by horizontal transmission and contribute to spread of this disease to indigenous European crayfish species.

  3. Comparative acute toxicity of neonicotinoid and pyrethroid insecticides to non-target crayfish (Procambarus clarkii) associated with rice-crayfish crop rotations.

    Science.gov (United States)

    Barbee, Gary C; Stout, Michael J

    2009-11-01

    Most insecticides used to control rice water weevil (Lissorhoptrus oryzophilus Kuscel) infestations are pyrethroids. However, pyrethroids are highly toxic to non-target crayfish associated with rice-crayfish crop rotations. One solution to the near-exclusive reliance on pyrethroids in a rice-crayfish pest management program is to incorporate neonicotinoid insecticides, which are insect specific and effective against weevils but not extremely toxic to crayfish. This study aimed to take the first step to assess neonicotinoids as alternatives to pyrethroids in rice-crayfish crop rotations by measuring the acute toxicities of three candidate neonicotinoid insecticides, clothianidin, dinotefuran and thiamethoxam, to juvenile Procambarus clarkii (Girard) crayfish and comparing them with the acute toxicities of two currently used pyrethroid insecticides, lambda-cyhalothrin and etofenprox. Neonicotinoid insecticides are at least 2-3 orders of magnitude less acutely toxic (96 h LC(50)) than pyrethroids to juvenile Procambarid crayfish: lambda-cyhalothrin (0.16 microg AI L(-1)) = etofenprox (0.29 microg AI L(-1)) > clothianidin (59 microg AI L(-1)) > thiamethoxam (967 microg AI L(-1)) > dinotefuran (2032 microg AI L(-1)). Neonicotinoid insecticides appear to be much less hazardous alternatives to pyrethroids in rice-crayfish crop rotations. Further field-level neonicotinoid acute and chronic toxicity testing with crayfish is needed. (c) 2009 Society of Chemical Industry.

  4. FEEDING PREFERENCES OF THE INVASIVE CRAYFISH, PROCAMBARUS CLARKII

    Directory of Open Access Journals (Sweden)

    Gherardi Francesca

    2007-10-01

    Full Text Available This laboratory study analyzes feeding preferences of a crayfish species with high invasive potentials, the red swamp crayfish Procambarus clarkii. We first conducted a series of multiple-choice tests among fresh plants (3 tests, one per each of three seasons, i.e. spring, summer, and autumn and animals (1 test in summer. In the first tests, crayfish were simultaneously offered fresh pieces of seven plants of different growth forms and taxonomic groups, selected on the basis of their availability in the habitat. In the second test, the offered animals were dead earthworms, rainbow trout fry, and toad tadpoles. Then, a binary choice test was run in autumn between the most preferred plant (Urtica sp. and earthworms. The percentages of organic C and N contents were measured for each food category using a gas-chromatography technique and the assimilation efficiency of both dry mass and organic content was assessed in a dedicated experiment. The results showed that P. clarkii is selective when offered fresh plants, consuming a relatively larger biomass of Urtica (in the three seasons examined, green algae (in spring, and Polygonum (in summer and autumn. Surprisingly, crayfish did not exhibit preference for any animal prey. Also, P. clarkii’s feeding decisions seemed not to be associated with either the availability of plants in the habitat or their occurrence in the gut contents of wild crayfish. Neither did their ingested biomass depend on the organic content or assimilation efficiency. Procambarus clarkii preferred Urtica sp. over earthworms, notwithstanding the higher nutritional value and assimilation efficiency of the latter. The above results might suggest that feeding preferences of the species often depend on factors other than nutritional value and digestibility. Future studies will analyze all the possible factors together in order to unravel the rules that govern feeding preferences in crayfish. In the case of invasive species, such

  5. Intensive removal of signal crayfish (Pacifastacus leniusculus) from rivers increases numbers and taxon richness of macroinvertebrate species.

    Science.gov (United States)

    Moorhouse, Tom P; Poole, Alison E; Evans, Laura C; Bradley, David C; Macdonald, David W

    2014-02-01

    Invasive species are a major cause of species extinction in freshwater ecosystems, and crayfish species are particularly pervasive. The invasive American signal crayfish Pacifastacus leniusculus has impacts over a range of trophic levels, but particularly on benthic aquatic macroinvertebrates. Our study examined the effect on the macroinvertebrate community of removal trapping of signal crayfish from UK rivers. Crayfish were intensively trapped and removed from two tributaries of the River Thames to test the hypothesis that lowering signal crayfish densities would result in increases in macroinvertebrate numbers and taxon richness. We removed 6181 crayfish over four sessions, resulting in crayfish densities that decreased toward the center of the removal sections. Conversely in control sections (where crayfish were trapped and returned), crayfish density increased toward the center of the section. Macroinvertebrate numbers and taxon richness were inversely correlated with crayfish densities. Multivariate analysis of the abundance of each taxon yielded similar results and indicated that crayfish removals had positive impacts on macroinvertebrate numbers and taxon richness but did not alter the composition of the wider macroinvertebrate community. Synthesis and applications: Our results demonstrate that non-eradication-oriented crayfish removal programmes may lead to increases in the total number of macroinvertebrates living in the benthos. This represents the first evidence that removing signal crayfish from riparian systems, at intensities feasible during control attempts or commercial crayfishing, may be beneficial for a range of sympatric aquatic macroinvertebrates.

  6. Conservation status of crayfishes of the United States and Canada

    Science.gov (United States)

    Christopher A. Taylor; Melvin L. Warren; J. F. Fitzpatrick; Horton H. Hobbs; Raymond F. Jezerinac; William L. Pflieger; Henry W. Robinson

    1996-01-01

    The American Fisheries Society (AFS) Endangered Species Committee herein provides a list of all crayfishes (families and Cambaridae) in the United States and Canada that includes state provincial distributions; a comprehensive review of the conservation status of all taxa; and references on biology, conservation, and...

  7. Natural crayfish clone as emerging model for various biological ...

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Biosciences; Volume 36; Issue 2. Marmorkrebs: Natural crayfish clone as emerging model for various biological disciplines. Günter Vogt. Mini-review Volume 36 Issue 2 June 2011 pp 377-382. Fulltext. Click here to view fulltext PDF. Permanent link:

  8. Short Note Invasive Australian crayfish Cherax quadricarinatus in ...

    African Journals Online (AJOL)

    Most crayfish were between 50 and 59.9 mm carapace length. Males (average 82.6 g) were significantly heavier than females (37.2 g) and males were larger in carapace length, carapace width, chela length and chela width. A feral population of C. quadricarinatus is now established in the Sanyati Basin. Possible modes of ...

  9. Potential impacts of alien freshwater crayfish in South Africa | de ...

    African Journals Online (AJOL)

    The habitat preferences and life history characteristics of four alien species of freshwater crayfish (Cherax tenuimanus, C. destructor, C. quadricarinatus and Procambarus clarkii) are reviewed. The potential impact of these species on South African freshwater ecosystems is assessed and the desirability of allowing their ...

  10. Crayfish: a newly recognized vehicle for vibrio infections.

    Science.gov (United States)

    Bean, N H; Maloney, E K; Potter, M E; Korazemo, P; Ray, B; Taylor, J P; Seigler, S; Snowden, J

    1998-10-01

    We conducted a 1-year case-control study of sporadic vibrio infections to identify risk factors related to consumption of seafood products in two coastal areas of Louisiana and Texas. Twenty-six persons with sporadic vibrio infections and 77 matched controls were enrolled. Multivariate analysis revealed that crayfish (P Vibrio parahemolyticus infection (OR 9.24, P vibrio infection.

  11. Crayfish Behavior: Observing Arthropods to Learn about Science & Scientific Inquiry

    Science.gov (United States)

    Rop, Charles J.

    2010-01-01

    This is a set of animal behavior investigations in which students will practice scientific inquiry as they observe crayfish, ask questions, and discuss territoriality, social interactions, and other behaviors. In doing this, they hone their skills of observation, learn to record and analyze data, control for variables, write hypotheses, make…

  12. Phylogenetic species delimitation for crayfishes of the genus Pacifastacus.

    Science.gov (United States)

    Larson, Eric R; Castelin, Magalie; Williams, Bronwyn W; Olden, Julian D; Abbott, Cathryn L

    2016-01-01

    Molecular genetic approaches are playing an increasing role in conservation science by identifying biodiversity that may not be evident by morphology-based taxonomy and systematics. So-called cryptic species are particularly prevalent in freshwater environments, where isolation of dispersal-limited species, such as crayfishes, within dendritic river networks often gives rise to high intra- and inter-specific genetic divergence. We apply here a multi-gene molecular approach to investigate relationships among extant species of the crayfish genus Pacifastacus, representing the first comprehensive phylogenetic study of this taxonomic group. Importantly, Pacifastacus includes both the widely invasive signal crayfish Pacifastacus leniusculus, as well as several species of conservation concern like the Shasta crayfish Pacifastacus fortis. Our analysis used 83 individuals sampled across the four extant Pacifastacus species (omitting the extinct Pacifastacus nigrescens), representing the known taxonomic diversity and geographic distributions within this genus as comprehensively as possible. We reconstructed phylogenetic trees from mitochondrial (16S, COI) and nuclear genes (GAPDH), both separately and using a combined or concatenated dataset, and performed several species delimitation analyses (PTP, ABGD, GMYC) on the COI phylogeny to propose Primary Species Hypotheses (PSHs) within the genus. All phylogenies recovered the genus Pacifastacus as monophyletic, within which we identified a range of six to 21 PSHs; more abundant PSHs delimitations from GMYC and ABGD were always nested within PSHs delimited by the more conservative PTP method. Pacifastacus leniusculus included the majority of PSHs and was not monophyletic relative to the other Pacifastacus species considered. Several of these highly distinct P. leniusculus PSHs likely require urgent conservation attention. Our results identify research needs and conservation priorities for Pacifastacus crayfishes in western

  13. Double blow: Alien crayfish infected with invasive temnocephalan in South African waters

    Directory of Open Access Journals (Sweden)

    Louis du Preez

    2013-09-01

    Full Text Available Trade in live, freshwater crayfish for ornamental markets, as well as for aquaculture, has grown rapidly and has become the major pathway for the introduction of non-indigenous crayfish species to several countries worldwide. Here we report on the first record of the Australian "redclaw" Cherax quadracarinatus in the natural waters of a game reserve in South Africa. To compound the situation, these redclaw crayfish were infected with a non-indigenous temnocephalan flatworm parasite. Both crayfish and temnocephalan were in full breeding condition, with young. Further spreading of this crayfish to the subtropical, water-rich, northern KwaZulu-Natal Province of South Africa and southern Mozambique is predicted. Not only might the crayfish compete with indigenous aquatic invertebrates but the non-host-specific temnocephalan might transfer to local decapods, such as freshwater crabs.

  14. A Trial of Natural Habitat Enclosure Traps as a Sampling Tool for Juvenile Crayfish

    OpenAIRE

    Fjälling, Arne; Engdahl, Fredrik; Edsman, Lennart; Bohman, Patrik; Sandström, Alfred

    2013-01-01

    Recruitment is a vital factor in the assessment, management and population dynamics of decapods. Since the juvenile stages of crayfish often prefer heterogeneous habitats, sampling with quantitative and reproducible methods have so far been challenging. We evaluate a new quantitative sampling method for juvenile crayfish; the enclosure trap. A field test was carried out during two consecutive years on a population of signal crayfish, Pacifastacus leniusculus, in littoral areas of Swedish Lake...

  15. A REVIEW OF INTERNATIONAL BIOSECURITY POLICY DEVELOPMENT IN RELATION TO MOVEMENTS OF FRESHWATER CRAYFISH

    Directory of Open Access Journals (Sweden)

    EDGERTON B. F.

    2002-07-01

    Full Text Available Freshwater crayfish are frequently traded, both alive (for human consumption or for fisheries/aquaculture stocking and as processed products (e.g. fresh or frozen, cooked or uncooked. As the experience in Europe with crayfish plague has shown, there can be significant risks of translocating pathogens with such trade. Such risks can be assessed in an import risk analysis process. This paper will concentrate on describing the principles of import risk analysis (IRA with particular reference to freshwater crayfish.

  16. UNDERSTANDING AND MANAGING BIODIVERSITY IN RELATION TO NATIVE CRAYFISH POPULATIONS IN EUROPE

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    GHERARDI F.

    2003-04-01

    Full Text Available The loss or diminution of European crayfish populations because of both habitat deterioration and competition with alien crayfish – also responsible for the dissemination of the crayfish plague – would reduce the biodiversity at the species level. The topic “What is meant by biodiversity?” in the context of native freshwater crayfish in Europe was discussed during the Kilkenny CRAYNET meeting in order to make the point about the varied meanings of biodiversity from genes and individuals to population levels.

  17. MANAGEMENT STRATEGIES, YIELD AND POPULATION DEVELOPMENT OF THE NOBLE CRAYFISH ASTACUS ASTACUS IN LAKE STEINSFJORDEN

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    SKURDAL J.

    2002-07-01

    Full Text Available Lake Steinsfjorden is the most important noble crayfish locality in Norway. The crayfish population has been monitored annually since 1979 including data on total trapping effort, yield and population composition before and after the catching season. The harvest has ranged from 0.7-4.7 kg.ha-1. The catch per trap night decreased prior to 1991 and the yield was reduced by some 50% over the years 1987-1992 as compared to 1979-1986. This was due to removal of small crayfish, high exploitation and the establishment of dense stands of Canadian pondweed (Elodea canadensis. Baited traps catch a large fraction of crayfish < 95 mm total length minimum size. These should according to the regulations immediately be released into the lake. However, it is apparent from the size composition that release of these small crayfish was rather incomplete. In 1983, trap mesh size was increased from 17.5 mm to 21 mm to reduce the fraction of undersized crayfish in the trap catches, yet no effects of this increased mesh size on crayfish size distribution were observed. The legal season has been reduced three times during the study period. In 1983, the closing date was changed from 31 December to 15 September. In 1989 the legal season was further reduced to two weeks and finally in 1995 to 10 days. This reduced total trap effort by 45%. The shorter season allow many crayfish to moult twice instead of once between seasons and the fraction of large crayfish has thus increased and so has the catch per trap night. Canadian pondweed has established dense annual stands and thus has made large parts of the shallow areas unsuitable for crayfish, causing an overall decrease in crayfish population size and production.

  18. Invasive crayfish threaten the development of submerged macrophytes in lake restoration.

    Science.gov (United States)

    van der Wal, Jessica E M; Dorenbosch, Martijn; Immers, Anne K; Vidal Forteza, Constanza; Geurts, Jeroen J M; Peeters, Edwin T H M; Koese, Bram; Bakker, Elisabeth S

    2013-01-01

    Submerged macrophytes enhance water transparency and aquatic biodiversity in shallow water ecosystems. Therefore, the return of submerged macrophytes is the target of many lake restoration projects. However, at present, north-western European aquatic ecosystems are increasingly invaded by omnivorous exotic crayfish. We hypothesize that invasive crayfish pose a novel constraint on the regeneration of submerged macrophytes in restored lakes and may jeopardize restoration efforts. We experimentally investigated whether the invasive crayfish (Procambarus clarkii Girard) affects submerged macrophyte development in a Dutch peat lake where these crayfish are expanding rapidly. Seemingly favourable abiotic conditions for macrophyte growth existed in two 0.5 ha lake enclosures, which provided shelter and reduced turbidity, and in one lake enclosure iron was added to reduce internal nutrient loading, but macrophytes did not emerge. We transplanted three submerged macrophyte species in a full factorial exclosure experiment, where we separated the effect of crayfish from large vertebrates using different mesh sizes combined with a caging treatment stocked with crayfish only. The three transplanted macrophytes grew rapidly when protected from grazing in both lake enclosures, demonstrating that abiotic conditions for growth were suitable. Crayfish strongly reduced biomass and survival of all three macrophyte species while waterfowl and fish had no additive effects. Gut contents showed that crayfish were mostly carnivorous, but also consumed macrophytes. We show that P. clarkii strongly inhibit macrophyte development once favourable abiotic conditions for macrophyte growth are restored. Therefore, expansion of invasive crayfish poses a novel threat to the restoration of shallow water bodies in north-western Europe. Prevention of introduction and spread of crayfish is urgent, as management of invasive crayfish populations is very difficult.

  19. Investigation of plutonium concentration and distribution in burrowing crayfish from the White Oak Creek floodplain

    Energy Technology Data Exchange (ETDEWEB)

    Delaney, M.S.; Dahlman, R.C.; Craig, R.B.

    1979-01-01

    The White Oak floodplain was contaminated with several radionuclides, including /sup 239/Pu, during the Manhattan Project in 1944. Plutonium distribution in the soil is nonhomogeneous. An investigation was conducted to deterine Pu accumulation in a resident animal population. Crayfish were chosen because they complete their life-cycle within the contaminated environment, they directly contact contaminated muds, and they function in a food chain of significance to man. Two major conclusions of the research were that Pu concentrations in contaminated crayfish typically exceed those of control crayfish by two orders of magnitude and that if an incident were to occur in which a standard man ingested the soft tissues of ten crayfish from the floodplain, an insignificant whole body dose would accrue over the subsequent 50 years of life. The digestive tract of contaminated crayfish contained 21 to 33% of the Pu body burden, soft tissues contained 11 to 31% of the Pu body burden, and 48 to 62% of the Pu body burden of contaminated crayfish was associated with the carapace. Therefore, at a molt a large proportion of its accumulated Pu is deposited in the environment. A supplementary laboratory investigation using /sup 237/Pu included a chronic Pu uptake study by uncontaminated crayfish. In these crayfish, from 64 to 82% of the /sup 237/Pu was associated with the body tissues. Complementary data for /sup 237/Pu associated with the carapace ranged from 18 to 37% of the distribution. An inventory of /sup 239/Pu in crayfish at two sites on the floodplain was calculated by multiplying the estimated biomass of the crayfish by their average /sup 239/Pu concentration. This evaluation of Pu associated with the crayfish population was compared to an inventory of /sup 239/Pu in the soil in which they burrow and was found to be eight orders of magnitude less.

  20. Investigation of plutonium concentration and distribution in burrowing crayfish from the White Oak Creek floodplain

    International Nuclear Information System (INIS)

    Delaney, M.S.; Dahlman, R.C.; Craig, R.B.

    1979-01-01

    The White Oak floodplain was contaminated with several radionuclides, including 239 Pu, during the Manhattan Project in 1944. Plutonium distribution in the soil is nonhomogeneous. An investigation was conducted to deterine Pu accumulation in a resident animal population. Crayfish were chosen because they complete their life-cycle within the contaminated environment, they directly contact contaminated muds, and they function in a food chain of significance to man. Two major conclusions of the research were that Pu concentrations in contaminated crayfish typically exceed those of control crayfish by two orders of magnitude and that if an incident were to occur in which a standard man ingested the soft tissues of ten crayfish from the floodplain, an insignificant whole body dose would accrue over the subsequent 50 years of life. The digestive tract of contaminated crayfish contained 21 to 33% of the Pu body burden, soft tissues contained 11 to 31% of the Pu body burden, and 48 to 62% of the Pu body burden of contaminated crayfish was associated with the carapace. Therefore, at a molt a large proportion of its accumulated Pu is deposited in the environment. A supplementary laboratory investigation using 237 Pu included a chronic Pu uptake study by uncontaminated crayfish. In these crayfish, from 64 to 82% of the 237 Pu was associated with the body tissues. Complementary data for 237 Pu associated with the carapace ranged from 18 to 37% of the distribution. An inventory of 239 Pu in crayfish at two sites on the floodplain was calculated by multiplying the estimated biomass of the crayfish by their average 239 Pu concentration. This evaluation of Pu associated with the crayfish population was compared to an inventory of 239 Pu in the soil in which they burrow and was found to be eight orders of magnitude less

  1. First evidence of crayfish plaque agent in populations of the marbled caryfish (Procambarus fallux forma virginalis)

    NARCIS (Netherlands)

    Keller, N.S.; Pfeiffer, M.; Roessink, I.; Schulz, R.; Schrimpf, A.

    2014-01-01

    The introduction of non-indigenous species and associated diseases can cause declines in indigenous flora and fauna and threaten local biodiversity. The crayfish plague pathogen (Aphanomyces astaci), carried and transmitted by latent infected North American crayfish, can lead to high mortalities in

  2. Range extensions of three crayfishes (Faxonius yanahlindus, F. placidus, and F. erichsonianus) into Mississippi

    Science.gov (United States)

    Susan B. Adams; Robert L. Jones

    2018-01-01

    We report 3 new state crayfish records from the Tennessee River drainage in Tishomingo County, Mississippi: 1 is a re-identification of previously published material, and 2 are from unpublished collections. Faxonius yanahlindus (Spinywrist Crayfish), recently described from the middle Tennessee River drainage in northwest Alabama and southern...

  3. ZEBRA MUSSEL COLONIZATION OF RUSTY CRAYFISH IN GREEN BAY, LAKE MICHIGAN

    Science.gov (United States)

    In August, 1995 six rusty crayfish colonized with zebra mussels were captured in small-meshed fyke-nets sets set apart as of a fish sampling effort at Peter's Marsh and Long-Tail Point Wetland in lower Green Bay. Mussels colonized virtually all areas of the crayfish bodies, but ...

  4. Signal crayfish as zoogeomorphic agents: diel patterns of fine sediment suspension in a crayfish-affected river and the implications for fine sediment fluxes and dynamics

    Science.gov (United States)

    Rice, Stephen; Johnson, Matthew; Reeds, Jake; Longstaff, Holly; Extence, Chris

    2013-04-01

    The signal crayfish (Pacifasticus leniusculus) is a formidable invasive species that has had a deleterious impact on native freshwater fauna across Europe. We contend that the impact of this animal extends beyond ecology into geomorphology and hypothesise that crayfish are significant agents of fine sediment recruitment and mobilisation, with potentially profound impacts on water quality, substrate quality and fine sediment fluxes. Building on pioneering work by colleagues at Queen Mary University, London this poster considers the role of crayfish in fine sediment suspension in a lowland, gravel-bed river. The hypothesis that nocturnal increases in crayfish activity are associated with a greater frequency of sediment suspension events and increases in ambient turbidity, is tested. Strong diel fluctuations in water turbidity were recorded at several sites on the Brampton Arm of the River Nene in England, a river heavily populated by signal crayfish, during August and September 2012. With the exception of three summer flood events, stage measurements during the same period were essentially flat, ruling out a hydraulic cause for overnight rises in turbidity. Water samples collected at midnight and at midday at one site confirm this diel pattern for suspended sediment concentration. Higher mean turbidity values overnight are associated with an increase in the magnitude and frequency of isolated turbidity spikes or events and this is consistent with crayfish nocturnalism. In particular, we suspect that turbidity events are caused by the construction and maintenenance of burrows and by interactions between crayfish and the river bed while foraging, fighting and avoiding each other. Tying the diel SSC signal directly to crayfish activity proved difficult, but several lines of argument presented here suggest that crayfish are the most likely cause of the diel pattern. These results provide substantial support for the idea that signal crayfish are important zoogeomorphic

  5. Are the effects of an invasive crayfish on lake littoral macroinvertebrate communities consistent over time?

    Directory of Open Access Journals (Sweden)

    Ruokonen T. J.

    2016-01-01

    Full Text Available Management of invasive species requires assessment of their effects on recipient ecosystems. However, impact assessment of invasive species commonly lacks a long-term perspective which can potentially lead to false conclusions. We examined the effects of the invasive signal crayfish (Pacifastacus leniusculus Dana on the stony littoral macroinvertebrate communities of a large boreal lake and assessed the extent to which the patterns observed in previous short-term studies were stable over time. We used temporal macroinvertebrate data collected in five consecutive years from a site with a well-established crayfish population, a site with no crayfish and a site where crayfish had been recently introduced. Our results revealed that signal crayfish had temporally rather consistent negative effects on the benthic macroinvertebrate assemblages but that the effects might be limited to certain taxa, in particular Gastropoda and Coleoptera. We also observed increases in Gastropoda density and taxa richness following a decline in crayfish density, indicating that the recovery of invertebrate assemblages might be fast. Hence, negative effects on benthic macroinvertebrates can likely be minimized by effective control of the signal crayfish population.

  6. THE FRESHWATER CRAYFISH AUSTROPOTAMOBIUS PALLIPESIN SOUTH TYROL: HERITAGE SPECIES AND BIOINDICATOR

    Directory of Open Access Journals (Sweden)

    FÜREDER L.

    2003-04-01

    Full Text Available Rapid decline of crayfish in European freshwaters and continuing threat necessitate integrated actions in conservation and management of native crayfish populations. Besides biological reasons (diseases, plague, the impact of toxic and harmful substances (fertilisers, herbicides or wastewater effluents, habitat alteration or fragmentation have been responsible for their decline in some regions. The same is true for the region of South Tyrol, where compared to previous investigations, only 10 of a former total of 15 crayfish locations in the water bodies could be affirmed. Although two new populations of the non-indigenous Astacus astacus were detected, the native Austropotamobius pallipes continues to decline. While many investigations have focused accurately on causal coherences for the decline of native populations, the properties of crayfish facilitate to reverse the situation. In a few examples, the potential of Austropotamobius pallipes, the native crayfish in South Tyrol, as “surrogate species” for effective biological conservation is discussed. Given the various adequate attributes of freshwater crayfish as surrogate species (including indicator species, umbrella species and flagship species qualities, they may help to advance not only the crayfish situation itself but also freshwater ecosystem properties in general.

  7. Do culverts impact the movements of the endangered white-clawed crayfish?

    Directory of Open Access Journals (Sweden)

    Louca V.

    2014-01-01

    Full Text Available Culverts can impact the migration and dispersal of aquatic animals and result in population fragmentation, increasing the risk of local extinction for endangered species such as the white-clawed crayfish Austropotamobius pallipes. This study used radio telemetry and passive integrated transponder (PIT telemetry to determine whether existing and experimental covered culverts affect the upstream and downstream movements of adult white-clawed crayfish. Daily crayfish movement rates did not differ significantly between an unlit 363-m long culvert and open stream channel sections. Crayfish moved into dark, covered sections volitionally. However, limited upstream movement occurred at sudden transitions of bed height or smooth-concrete box culvert sections with fast flow, suggesting partial barrier effects. In the 20-m long experimental in-stream culvert, also dark, but with natural stream bed, 70% of radio-tagged crayfish released downstream entered the culvert, as did 60% of those released upstream. Overall 35% passed through, with similar numbers in each direction. We conclude that dark culverts up to several hundred metres do not inhibit dispersal of white-clawed crayfish, provided stream slope, bed type and water velocity are amenable for movement and refuge. Care is required to ensure that culverts are bioengineered to ensure that average water velocity is sufficiently low and local hydraulic variation high, the bed and/or sidewalls contain refuge structures, and there are no cross-channel steps in bed level. Smooth-bedded box culverts are unlikely to be suitable for white-clawed crayfish.

  8. Continental-wide distribution of crayfish species in Europe: update and maps

    Directory of Open Access Journals (Sweden)

    Kouba A.

    2014-01-01

    Full Text Available Recently published astacological studies substantially improved available data on distribution of crayfish in various European regions. At the same time, spread of invasive species has been recorded, additional non-indigenous species became established in various countries, and losses of populations of native species due to crayfish plague and other negative factors were observed. We overview recent advances in this knowledge, and provide updated colour maps of the distribution of all crayfish species present in Europe. These maps are originally based on the data from the Atlas of Crayfish in Europe published in 2006 as a result of the CRAYNET project, and were further updated from more recently published reports, grey literature, and especially thanks to contributions and feedback of over 70 specialists from 32 countries. Separate maps are available for all indigenous crayfish species in Europe as well as for three most widespread non-indigenous crayfish species. Additionally, two maps give locations of known findings of crayfish species introduced to Europe after 1980. These newly established alien species have so far restricted distributions; however, the frequency of recent reports suggests that findings of such species resulting from releases of aquarium pets will further increase.

  9. Antibacterial activity of hemocyanin from red swamp crayfish (Procambarus clarkii).

    Science.gov (United States)

    Qin, Zhendong; Babu, V Sarath; Wan, Quanyuan; Muhammad, Asim; Li, Jun; Lan, Jiangfeng; Lin, Li

    2018-04-01

    Hemocyanins (HMC): the copper-containing respiratory proteins present in invertebrate hemolymph, which plays many essential roles in the immune system. Currently, little is known about the HMC domains of Procambarus clarkii (P. clarkii) and their function in antimicrobial immune response. In this present study, we comparatively studied the expression pattern of native PcHMC with the three recombinant proteins of variable domains of crayfish hemocyanin (PcHMC-N, N-terminal domain of hemocyanin; PcHMC-T, tyrosinase domain of hemocyanin; PcHMC-C, C-terminal domain of hemocyanin). The results showed that three purified recombinant proteins had a strong binding to various bacteria and lipopolysaccharides that further highly agglutinated. The HMCs recombinant proteins showed strong antibacterial activity against V. parahaemolyticus and S. aureus by bacterial growth inhibition, phenoloxidase (PO) and phagocytosis assays. Specifically, rPcHMC1-T and rPcHMC1-C inhibited both the bacteria efficiently, rPcHMC1-T was highly upregulated the PO activity than the other recombinant proteins. Whereas, recombinant proteins pretreated crayfish hemocytes participated in phagocytosis activity, rPcHMC1-N and rPcHMC1-C proteins had a profound effect than the rPcHMC1-T on S. aureus and V. parahaemolyticus phagocytosis. The crayfish hemocyanin domains clearly exhibited antibacterial and phagocytic activities against both the bacteria, suggesting that its variable domains of hemocyanin have the different function on specific pathogen during the assault of pathogens. Copyright © 2018 Elsevier Ltd. All rights reserved.

  10. WHITE-CLAWED CRAYFISH IN MUDDY HABITATS: MONITORING THE POPULATION IN THE RIVER IVEL, BEDFORDSHIRE, UK

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    PEAY S.

    2006-01-01

    Full Text Available White-clawed crayfish Austropotamobius pallipes are usually associated with stony substrates, tree roots, or refuges in submerged banks. The River Ivel has the last known population of white-clawed crayfish in Bedfordshire. Prior to 2005, much of the bed comprised uniform silt, plus leaf-litter. Stands of reedmace Typha latifolia and other emergent vegetation were localised in less shaded areas. Initial survey results suggested a population at low abundance. A low-cost monitoring strategy was started in 2001 and continued three times a year to 2005, using engineering bricks, which offer artificial refuges. Crayfish are counted when bricks are lifted periodically. De-silting of c. 430 m river was carried out in February 2005, to improve habitat and to maintain the flood capacity in the channel upstream of a mill weir. Additional bricks were deployed a few weeks in advance of de-silting, then bricks and crayfish were lifted prior to dredging and were returned the next day. Starting upstream, soft, wet mud was dredged out, placed on the bank and searched manually for crayfish. Banks, tree roots and shallow margins were left undisturbed. In all, 4,142 crayfish were found in dredgings from a 430 m length of the mid channel. Crayfish were strongly associated with emergent vegetation, but many were present below the surface of the silt. Crayfish released in the dredged channel immediately burrowed into the silt retained on the channel margins. Monitoring after dredging showed no change in abundance in the main area with in-bank refuges and lots of bricks, but there was an increase in occupancy of bricks in an area where most crayfish had been in emergent vegetation.

  11. Mitochondrial cytochrome oxidase I gene analysis indicates a restricted genetic background in Finnish noble crayfish (Astacus astacus stocks

    Directory of Open Access Journals (Sweden)

    Makkonen J.

    2015-01-01

    Full Text Available The IUCN Red List indexes the noble crayfish (Astacus astacus as vulnerable, with a declining population trend. The main threats to the species are the crayfish plague caused by the oomycete Aphanomyces astaci and the introduced North American crayfish that act as the carriers of this disease. In Finland, the noble crayfish is considered as a native species, which original distribution area covers the southern part of the country, but the species distribution has been dispersed to cover almost the whole country. The aim of this study was to survey the genetic diversity among the Finnish noble crayfish populations. The mitochondrial cytochrome oxidase I (COI-gene was sequenced from 742 individuals representing 59 populations from Finland and Estonia. As a result, only a single haplotype was found. Based on these results, the genetic diversity of noble crayfish in its Northern distribution range is remarkably low. The observed lack of variation can result from several mechanisms including small size of the founder population and the intense spreading of the species by manmade stockings. The restricted diversity can also be caused by eradication of the original populations due to crayfish plague epidemics and spreading of the invasive crayfish species carrying the crayfish plague. It is also possible that all contemporary Finnish noble crayfish populations originate from stockings with no variation in respect to COI-gene.

  12. Status of the white-clawed crayfish, Austropotamobius pallipes (Lereboullet, 1858, in Spain : distribution and legislation

    Directory of Open Access Journals (Sweden)

    ALONSO F.

    2000-01-01

    Full Text Available The white-clawed crayfish, Austropotamobius pallipes, is the only native species of freshwater crayfish in Spain. This species sustained a first-magnitude inland fishery up to the end of 1970's, when the crayfish plague struck the Spanish waters. It is detected an overall loss of distribution area of populations inhabiting the medium and lower reaches of the main river catchments, especially in Southern and Central Spain. The number of surviving populations can be estimated in ca. 700. Remaining native crayfish populations currently inhabit marginal areas. The populations are very fragmented, occupy short stretches, and are frequently isolated from the main river system. The current distribution is the result of a sum of different factors, i.e. crayfish plague, habitat alterations, extreme climatic drought, etc. The incidence and relative importance of each one varied during the last 15 years, with crayfish plague being a predominant negative factor in the seventies and eighties, and climatic drought in the nineties. The current trend of disappearance is a sufficient reason to consider the native crayfish as at risk of extinction. However neither the national legislation nor most of the regional government legislations have listed this species as endangered. An analysis of the legislation dealing with freshwater crayfish in Spain shows : (a an uneven and generally low level of protection given to the native species and (b a very complex fishing and commercialization regulations for crayfish that show significant changes from one region to another. This complex legislation, complemented with a general lack of data on crayfish populations, low levels of management and public involvement, and different strategies in regional governments regarding restocking programs with exotic species, makes a confusing situation. In order to decrease the general tendency of regression of A. pallipes a conservation program for this species needs to be implemented

  13. CRAYFISH AND ITS CULTURE IN UKRAINE. THEMATIC REFERENCES LIST

    Directory of Open Access Journals (Sweden)

    I. Hrytsyniak

    2014-09-01

    Full Text Available Purpose. To compile a thematic references list on the problems of biology, physiology, pathology and crayfish breeding in Ukraine. Methodology. As the search base for the realization of the purpose was the scientific library stock of the Institute of Fisheries NAAS. The methods that have been preferred were both integrated and selective. Findings. We prepared a thematic reference list of the main scientific works, such as collections of scientific papers, proceedings of international scientific conferences, articles and candidate’s thesis abstracts on the biology of crustaceans and their cultivation in Ukraine, including the literature sources since 1958. The bibliography contains 37 publications of the Institute of Fisheries NAAS scientific library stock, in alphabetical order, and described according to DSTU GOST 7.1:2006 «System of standards on information, librarianship and publishing. Bibliographic entry. Bibliographic description. General requirements and rules». Practical value. The list may be helpful for experts, scientists, students, who are interested in problems of crayfish biology and culture.

  14. Distribution of native and exotic branchiobdellidans (Annelida: Clitellata) on their respective crayfish hosts in northern Italy, with the first record of native Branchiobdella species on an exotic North American crayfish.

    OpenAIRE

    Joy N. RAYBURN; Giovanni B. DELMASTRO; Stuart R. GELDER

    1999-01-01

    Branchiobdellidans were found on crayfish at the 18 sites examined in northern Italy. At 15 of the sites the native crayfish, Austropotamobius pallipes, was collected and all supported specimens of Branchiobdella italica. A few specimens of B. parasita were found at only two of these sites and no specimens of B. hexodonta were observed during the survey. The North American Louisiana red swamp crayfish, Procambarus (Scapulicambarus) clarkii has been found in three additional sites around Carma...

  15. Spatial dynamics of the noble crayfish (Astacus astacus, L. in the Paklenica National Park

    Directory of Open Access Journals (Sweden)

    G.I.V. Klobucar

    2008-07-01

    Full Text Available The aim of this work was to analyse the spatial dynamics of a noble crayfish population inhabiting the Velika Paklenica Stream (Paklenica National Park, Croatia. The study was conducted in July 2000, and between March and September 2002. Crayfish were trapped by baited LiNi traps and hand-made traps at two localities over 25 nights. We recorded the precise position of the captured crayfish, their sex, and total length. Crayfish were individually marked and then released back into the stream at the same spot where they were caught. Spatial analyses included determination of movement direction, distribution type, home range, total distance travelled, and mean daily movement. A mean home range of approximately 19 m was calculated. No difference in home range between the sexes was found. There was a large individual variation in the extent of movement without any effect of sex or size.

  16. ROUNDTABLE SESSION 3: PHYLOGENY OF EUROPEAN CRAYFISH – IMPROVING THE TAXONOMY OF EUROPEAN CRAYFISH FOR A BETTER CONSERVATION

    Directory of Open Access Journals (Sweden)

    SCHULZ H. K.

    2005-07-01

    Full Text Available This paper summarizes the various themes discussed in a roundtable session on the uses and usefulness of genetics for conservation of our European crayfish heritage. After reviewing the importance of characterizing the different genetic stocks (ESU: Evolutionary Significant Units of a species, where morphological criteria used for taxonomy, are utilizable with caution, the present state of knowledge of the phylogeny of European species was determined, in particular for the genus Austropotamobius which occupies most studies. There was a lively debate on the elevation to species rank of A. italicus. The status of knowledge of the taxonomy of Astacus astacus has been presented. Finally, given a major increase in works describing the genetic variability of natural populations of European crayfish, it was evident that an up to date inventory of the different research teams in this field should be developed, for several reasons – (i to describe these teams and their managers (thus facilitating contact (ii to list the species studied and the markers used (iii to give some recommendations on standardizing the use of certain markers or genes so as to allow comparison between the results collected by the various teams, and to apply them on a broader geographic scale.

  17. Stream permanence influences crayfish occupancy and abundance in the Ozark Highlands, USA

    Science.gov (United States)

    Yarra, Allyson N.; Magoulick, Daniel D.

    2018-01-01

    Crayfish use of intermittent streams is especially important to understand in the face of global climate change. We examined the influence of stream permanence and local habitat on crayfish occupancy and species densities in the Ozark Highlands, USA. We sampled in June and July 2014 and 2015. We used a quantitative kick–seine method to sample crayfish presence and abundance at 20 stream sites with 32 surveys/site in the Upper White River drainage, and we measured associated local environmental variables each year. We modeled site occupancy and detection probabilities with the software PRESENCE, and we used multiple linear regressions to identify relationships between crayfish species densities and environmental variables. Occupancy of all crayfish species was related to stream permanence. Faxonius meeki was found exclusively in intermittent streams, whereas Faxonius neglectus and Faxonius luteushad higher occupancy and detection probability in permanent than in intermittent streams, and Faxonius williamsi was associated with intermittent streams. Estimates of detection probability ranged from 0.56 to 1, which is high relative to values found by other investigators. With the exception of F. williamsi, species densities were largely related to stream permanence rather than local habitat. Species densities did not differ by year, but total crayfish densities were significantly lower in 2015 than 2014. Increased precipitation and discharge in 2015 probably led to the lower crayfish densities observed during this year. Our study demonstrates that crayfish distribution and abundance is strongly influenced by stream permanence. Some species, including those of conservation concern (i.e., F. williamsi, F. meeki), appear dependent on intermittent streams, and conservation efforts should include consideration of intermittent streams as an important component of freshwater biodiversity.

  18. Are Chinese consumers at risk due to exposure to metals in crayfish? A bioaccessibility-adjusted probabilistic risk assessment.

    Science.gov (United States)

    Peng, Qian; Nunes, Luís M; Greenfield, Ben K; Dang, Fei; Zhong, Huan

    2016-03-01

    Freshwater crayfish, the world's third largest crustacean species, has been reported to accumulate high levels of metals, while the current knowledge of potential risk associated with crayfish consumption lags behind that of finfish. We provide the first estimate of human health risk associated with crayfish (Procambarus clarkii) consumption in China, the world's largest producer and consumer of crayfish. We performed Monte Carlo Simulation on a standard risk model parameterized with local data on metal concentrations, bioaccessibility (φ), crayfish consumption rate, and consumer body mass. Bioaccessibility of metals in crayfish was found to be variable (68-95%) and metal-specific, suggesting a potential influence of metal bioaccessibility on effective metal intake. However, sensitivity analysis suggested risk of metals via crayfish consumption was predominantly explained by consumption rate (explaining >92% of total risk estimate variability), rather than metals concentration, bioaccessibility, or body mass. Mean metal concentrations (As, Cd, Cu, Ni, Pb, Se and Zn) in surveyed crayfish samples from 12 provinces in China conformed to national safety standards. However, risk calculation of φ-modified hazard quotient (HQ) and hazard index (HI) suggested that crayfish metals may pose a health risk for very high rate consumers, with a HI of over 24 for the highest rate consumers. Additionally, the φ-modified increased lifetime risk (ILTR) for carcinogenic effects due to the presence of As was above the acceptable level (10(-5)) for both the median (ILTR=2.5×10(-5)) and 90th percentile (ILTR=1.8×10(-4)), highlighting the relatively high risk of As in crayfish. Our results suggest a need to consider crayfish when assessing human dietary exposure to metals and associated health risks, especially for high crayfish-consuming populations, such as in China, USA and Sweden. Copyright © 2016 Elsevier Ltd. All rights reserved.

  19. Assessing the importance of food for improving noble crayfish culture conditions

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    Rusch J.C.

    2015-01-01

    Full Text Available Captive breeding and crayfish culture are considered important measures in species protection activities. Thus, knowledge on optimal feeding of crayfish in captivity is needed in order to secure minimal mortality and prevent detrimental effects to health. To optimize conditions of crayfish prior to subsequent stocking, feeding trials were conducted with the aim of investigating the connection between food intake, food preference and temperature under near natural conditions. During a five-month period, noble crayfish were fed on fish, carrots, algae and chironomid-larvae according to a pre-defined rotation system, whereby the ambient water temperature ranged from 5 °C to 13 °C, following the natural temperature regime. The results of these feeding trials demonstrate a direct correlation between rising temperature and increasing food intake for water temperatures exceeding 8 °C. Food intake is further influenced by the variety of food items available at any one time. The results also confirm that Astacus astacus has a strong preference for fish and that alternation of food types has an impact on consumption. Our results prompt the following recommendations for optimized feeding conditions of crayfish in captivity prior to their release: (1 a balanced diet containing not only plant tissue but also a significant proportion of animal tissue and (2 the amount of available food must be adjusted according to the carapace length of the crayfish.

  20. EXPERIMENTAL EVIDENCE FOR HOMING IN THE RED SWAMP CRAYFISH, PROCAMBARUS CLARKII

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    BARBARESI S.

    2006-01-01

    Full Text Available The red swamp crayfish, Procambarus clarkii, is an efficient burrower, but its burrow fidelity has been recently questioned. In this study, we aimed at investigating whether individuals of this species are capable to learn the position of a goal (a wet burrow hidden to their sight in experimental tanks and to make more efficient with time their oriented movement towards it. We also analyzed crayfish behavior after having closed one of the two accesses to the goal. Indeed, in successive trials we recorded the crayfish tendency to reduce the distance covered to reach the goal and the time taken, except when they were already familiar to the experimental setting. Memory of the spatial configuration lasted for 16 hours at least and crayfish learned and maintained individual trajectories. The interruption of their usual path always caused a drastic increase of distance and time that however decreased in the successive trials. This study provided also some information of the sensory channels used by P. clarkii to orient. This crayfish, which can be active also during daytime, seemed to adopt a combination of tactile and visual information, together with the possible use of cues (i.e. humidity cues emitted by the goal. Future studies should clarify the paradox of a crayfish species whose individuals, although being physiologically capable to home, seem not to return to the previously occupied burrows at the end of their foraging excursions, notwithstanding the time and energy expended to excavate them.

  1. Incomes, Attitudes, and Occurrences of Invasive Species: An Application to Signal Crayfish in Sweden

    Science.gov (United States)

    Gren, Ing-Marie; Campos, Monica; Edsman, Lennart; Bohman, Patrik

    2009-02-01

    This article analyzes and carries out an econometric test of the explanatory power of economic and attitude variables for occurrences of the nonnative signal crayfish in Swedish waters. Signal crayfish are a carrier of plague which threatens the native noble crayfish with extinction. Crayfish are associated with recreational and cultural traditions in Sweden, which may run against environmental preferences for preserving native species. Econometric analysis is carried out using panel data at the municipality level with economic factors and attitudes as explanatory variables, which are derived from a simple dynamic harvesting model. A log-normal model is used for the regression analysis, and the results indicate significant impacts on occurrences of waters with signal crayfish of changes in both economic and attitude variables. Variables reflecting environmental and recreational preferences have unexpected signs, where the former variable has a positive and the latter a negative impact on occurrences of waters with signal crayfish. These effects are, however, counteracted by their respective interaction effect with income.

  2. STUDIES ON THE WHITE-CLAWED CRAYFISH (AUSTROPOTAMOBIUS PALLIPES ASSOCIATED WITH MUDDY HABITATS

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    HOLDICH D. M.

    2006-01-01

    Full Text Available The white-clawed crayfish, Austropotamobius pallipes, is usually found associated with stony habitats containing obvious refuges in the form of gaps between and under rocks, macrophytes and marginal tree roots, particularly in streams and lakes with clear water and little marginal mud. If the banks are composed of suitable material, then they may also construct and live in burrows. However, the white-clawed crayfish is also found to be abundant in streams, rivers, canals and millraces with deep, anoxic mud and with very little aquatic vegetation. Foraging on the surface of mud may be the only way they can obtain sufficient food in the form of macroinvertebrates and decaying plant matter. Where do crayfish live in this restricted habitat? Dewatering such waterways for essential engineering works, such as desilting, bridge and weir repairs, bank reinforcements, and maintenance of outfalls can provide an excellent opportunity to study the available habitat and the crayfish populations, in addition good estimates of population size and age class distribution can be obtained, although, as with other methods, juveniles tend to be underrepresented. A number of case studies will be given to illustrate the fact that white-clawed crayfish are able to colonize muddy habitats in some numbers. The value of retaining trees with their roots hanging into waterways as a refuge for both crayfish and small fish is highlighted.

  3. Glutamatergic postsynaptic block by Pamphobeteus spider venoms in crayfish.

    Science.gov (United States)

    Araque, A; Ferreira, W; Lucas, S; Buño, W

    1992-01-31

    The effects of toxins from venom glands of two south american spiders (Pamphobeteus platyomma and P. soracabae) on glutamatergic excitatory synaptic transmission were studied in the neuromuscular junction of the opener muscle of crayfish. The toxins selectively and reversibly blocked both excitatory postsynaptic currents and potentials in a dose-dependent manner. They also reversibly abolished glutamate-induced postsynaptic membrane depolarization. They had no effect on resting postsynaptic membrane conductance nor on postsynaptic voltage-gated currents. The synaptic facilitation and the frequency of miniature postsynaptic potentials were unaffected by the toxins, indicating that presynaptic events were not modified. Picrotoxin, a selective antagonist of the gamma-aminobutyric acid (GABA)A receptor, did not modify toxin effects. We conclude that both toxins specifically block the postsynaptic glutamate receptor-channel complex.

  4. Red swamp crayfish: biology, ecology and invasion - an overview

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    Tainã Gonçalves Loureiro

    Full Text Available ABSTRACTAlien species have been transported and traded by humans for many centuries. However, with the era of globalization, biological invasions have reached notable magnitudes. Currently, introduction of alien species is one of the major threats to biodiversity and ecosystem functioning. The North American crayfish Procambarus clarkii is one of the most widely introduced freshwater species in the world, especially due to its high economic importance. It is responsible for great modifications in invaded environments causing irreparable ecological and economic damages. Its impressive ability to successfully colonize a wide range of environments is a consequence of its behavioural and biological characteristics that can adapt to features of the invaded location, conferring to this species a notable ecological plasticity. This review summarizes the available information regarding P. clarkii's biology and invasive dynamics around the world in order to contribute to the understanding of the threats posed by its establishment, as well as to support management and impact mitigation efforts.

  5. Crayfish Self-Administer Amphetamine in a Spatially Contingent Task

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    Udita Datta

    2018-05-01

    Full Text Available Natural reward is an essential element of any organism’s ability to adapt to environmental variation. Its underlying circuits and mechanisms guide the learning process as they help associate an event, or cue, with the perception of an outcome’s value. More generally, natural reward serves as the fundamental generator of all motivated behavior. Addictive plant alkaloids are able to activate this circuitry in taxa ranging from planaria to humans. With modularly organized nervous systems and confirmed vulnerabilities to human drugs of abuse, crayfish have recently emerged as a compelling model for the study of the addiction cycle, including psychostimulant effects, sensitization, withdrawal, reinstatement, and drug reward in conditioned place preference paradigms. Here we extend this work with the demonstration of a spatially contingent, operant drug self-administration paradigm for amphetamine. When the animal enters a quadrant of the arena with a particular textured substrate, a computer-based control system delivers amphetamine through an indwelling fine-bore cannula. Resulting reward strength, dose-response, and the time course of operant conditioning were assessed. Individuals experiencing the drug contingent on their behavior, displayed enhanced rates of operant responses compared to that of their yoked (non-contingent counterparts. Application of amphetamine near the supra-esophageal ganglion elicited stronger and more robust increases in operant responding than did systemic infusions. This work demonstrates automated implementation of a spatially contingent self-administration paradigm in crayfish, which provides a powerful tool to explore comparative perspectives in drug-sensitive reward, the mechanisms of learning underlying the addictive cycle, and phylogenetically conserved vulnerabilities to psychostimulant compounds.

  6. KEYNOTE PRESENTATION AND ROUNDTABLE SESSION 4. CRAYFISH PATHOLOGY IN EUROPE:PAST, PRESENT AND A PROGRAMME FOR THE FUTURE

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    EDGERTON B. F.

    2004-01-01

    Full Text Available The devastating affects of disease on European freshwater crayfish are well known as epizootics in wild populations have occurred throughout much of Europe since the mid XVIIIe s. After protracted and rigorous debate, the cause of the disease named crayfish plague was proved to be the fungus Aphanomyces astaci in 1934. In the last 70 years, much of the research conducted in the field of crayfish pathology has concentrated on fungi, especially improving diagnostic techniques for A. astaci. Similarly, diagnostic responses to epizootics in European crayfish have concentrated almost entirely on fungal isolation and/or identification. On the other hand, viruses have proved to be the most important pathogens in the growing global crustacean aquaculture and fishery industries. Rickettsia-like organisms (RLO are also important. Critically, diagnostic techniques necessary to detect the full range of potential pathogens of crayfish are rarely utilized in the field of crayfish pathology in Europe. Histopathological analysis, required for the diagnosis of infections by viruses and RLOs, is absent from most European studies. Epizootics unrelated to A. astaci in European crayfish and epizootics in introduced American crayfish species highlight the inadequate current state of knowledge in the field. Presently, the field is ill-equipped to determine the cause(s of these epizootics. Moreover, crayfish conservation strategies may be undermined and even detrimental to the longterm goals; eg., stocking programs may spread undetected pathogens. Therefore, critical limitations in the field of crayfish pathology have major repercussions in management of freshwater crayfish. Guiding principles and a concept for a trans-European Community research and education program were developed to address this serious issue and are presented herein.

  7. Distribution of native and exotic branchiobdellidans (Annelida: Clitellata on their respective crayfish hosts in northern Italy, with the first record of native Branchiobdella species on an exotic North American crayfish.

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    Joy N. RAYBURN

    1999-02-01

    Full Text Available Branchiobdellidans were found on crayfish at the 18 sites examined in northern Italy. At 15 of the sites the native crayfish, Austropotamobius pallipes, was collected and all supported specimens of Branchiobdella italica. A few specimens of B. parasita were found at only two of these sites and no specimens of B. hexodonta were observed during the survey. The North American Louisiana red swamp crayfish, Procambarus (Scapulicambarus clarkii has been found in three additional sites around Carmagnola, south of Torino. The exotic Cambarincola mesochoreus was recovered from red crayfish at two sites. However, no specimens of C. mesochoreus were found at the third site, but specimens B. italica and B. parasita were identified. This is the first record of native Branchiobdella spp. on an exotic and wild crayfish in northern Italy.

  8. Diet of the crayfish Paranephrops zealandicus in bush and pasture streams : insights from stable isotopes and stomach analysis

    International Nuclear Information System (INIS)

    Hollows, J.W.; Townsend, C.R.; Collier, K.J.

    2002-01-01

    Crayfish (Paranephrops zealandicus White) stomachs from streams in both native bush (mainly tree leaves and dicotyledonous seeds) and exotic pasture settings (mainly grass stems and monocotyledonous seeds) were dominated by allochthonous material. More detritus occurred in stomachs in autumn-winter than in spring-summer, but quantities were similar in crayfish from native bush and pasture streams. The stomachs of larger crayfish contained a significantly greater proportion of detritus than smaller individuals. Aquatic invertebrates were the second most abundant dietary category by volume, with highest values in winter, but there were no significant differences between land uses or crayfish size classes. A wide range of invertebrates was eaten by crayfish, with mayfly nymphs, chironomid larvae, and snails predominating. The latter were numerically more prominent in crayfish from bush than pasture streams. Terrestrial invertebrates were recorded from 4% of stomachs, but there were no significant differences in relation to land use, season, or crayfish size class. Despite aquatic invertebrates making up 13 C and perhaps of microfloral origin, seems to be an important energy source for crayfish in both stream types. (author). 52 refs., 5 figs., 2 tabs

  9. REVIEW OF THE NATIONAL RESTOCKING PROGRAMME “ACTIVE PROTECTION OF NATIVE CRAYFISH IN POLAND” 1999-2001

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    ŠMIETANA P.

    2004-01-01

    Full Text Available After the first spread of crayfish plague (aphanomycosis at the end of the nineteenth century, the formerly abundant populations of native crayfish in Poland declined drastically. Analysis of historical data on the occurrence and distribution of crayfish in Poland led to the conclusion that without human intervention the native crayfish species would be at high risk of being made extinct. The largest programme concerning crayfish monitoring and restocking in Poland was “Active protection of native crayfish in Poland” conducted by the Inland Fisheries Institute, the Department of Ecology, University of Szczecin, the Department of Zoology, Warsaw Agricultural University and the University of Warmia and Mazury that was funded by the EkoFundusz Foundation and Inland Fisheries Institute in 1999-2001. One of the main objectives and results of this programme was the determination of indigenous crayfish distribution in Poland (mainly Astacus astacus and Astacus leptodactylus and the restocking of suitable habitats with indigenous crayfish. The densest populations (> 2 500 adult individuals per hectare were used as a source of restocking material. Restocking was performed in 54 water bodies using a total of 45 200 individuals of A. astacus and 9 800 of A. leptodactylus. Between 2001-2002, the success of the restocking programme was monitored. According to the results obtained so far, the restocking exercise has been successful in at least 60.8% of the cases.

  10. CRAYFISH PREDATION EXPERIMENTS ON THE INTRODUCED ZEBRA MUSSEL, DREISSENA POLYMORPHA, IN IRELAND, AND THEIR POTENTIAL FOR BIOCONTROL.

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    REYNOLDS J. D.

    2001-04-01

    Full Text Available The zebra mussel Dreissena polymorpha, native to the Aralo-Caspian region, has spread across Europe in the last 180 years. Although it reached England in 1820, it only arrived in Ireland in around 1995, probably attached to the hull of pleasure boats, and since then has spread through the lowland Shannon and Erne systems, which are linked by canal. While White-clawed crayfish Austropotamobius pallipes (Lereboullet occur in these systems, Dreissena has not yet colonized sites with large crayfish populations. In laboratory experiments crayfish of both sexes ranging in size from 32-48 mm carapace length (CL were offered zebra mussels in 7 size classes spanning a range from 3-17 mm total length. Crayfish fed most on small mussels, although there was some correlation between size of crayfish and largest mussels attacked. When eaten mussels were not replaced, crayfish shifted to larger sizes. In the presence of alternative prey, experienced crayfish ate mussels and alternative foods in similar amounts while those who had never encountered zebra mussels nearly always chose the alternative foods first. The possibility of crayfish exerting significant controlling impacts on expanding mussel populations is discussed.

  11. The potential for using red claw crayfish and hybrid African catfish as biological control agents for Schistosoma host snails

    NARCIS (Netherlands)

    Monde, C.; Syampungani, S.; Rico, A.; Brink, van den P.J.

    2017-01-01

    The potential of red claw crayfish and hybrid African catfish (Clarias gariepinus and Clarias ngamensis) as predators for Schistosoma host snails was evaluated in 2014 by monitoring the consumption of snails by crayfish and catfish in experimental tanks over time under laboratory conditions. After

  12. Accumulation of Heavy Metals in Crayfish and Fish from Selected Czech Reservoirs

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    Iryna Kuklina

    2014-01-01

    Full Text Available To evaluate the accumulation of aluminium, cadmium, chromium, copper, lead, mercury, nickel, and zinc in crayfish and fish organ tissues, specimens from three drinking water reservoirs (Boskovice, Landštejn, and Nová Říše and one contaminated site (Darkovské moře in the Czech Republic were examined. Crayfish hepatopancreas was confirmed to be the primary accumulating site for the majority of metals (Cu > Zn > Ni > Cd > Cr, while Hg and Cr were concentrated in abdominal muscle, and Al and Pb were concentrated in gill. Metals found in Nová Říše specimens included Cu > Zn > Ni and those found in Boskovice included Zn > Hg > Cr. Cd concentrations were observed only in Landštejn specimens, while contaminated Darkovské moře specimens showed the highest levels of accumulation (Cu > Al > Zn > Pb. The majority of evaluated metals were found in higher concentrations in crayfish: Cu > Al > Zn > Ni > Cr > Cd > Pb, with Hg being the only metal accumulating higher in fish. Due to accumulation similarities of Al in crayfish and fish gill, differences of Hg in muscle, and features noted for the remaining metals in examined tissues, biomonitoring should incorporate both crayfish and fish to produce more relevant water quality surveys.

  13. Cadmium-binding proteins in midgut gland of freshwater crayfish Procambarus clarkii

    Energy Technology Data Exchange (ETDEWEB)

    Del Ramo, J.; Pastor, A.; Torreblanca, A.; Medina, J.; Diza-Mayans, J.

    1989-02-01

    Metallothioneins, metal binding proteins, were originally isolated and characterized by Margoshes and Vallee. These proteins have a high affinity for various heavy metals, particularly cadmium and mercury and have extensively been studied in mammals. Metal binding proteins have been observed in a variety of marine invertebrates; however, there is very little information available on metal binding proteins in freshwater invertebrates, and particularly in freshwater crustaceans. Cadmium is an ubiquitous non essential element which possesses high toxicity to aquatic organisms. Cadmium binding proteins observed in invertebrates have similar characteristics to mammalian metallothioneins. In 1978, the American red crayfish appeared in Albufera Lake and the surrounding rice fields (Valencia, Spain). Albufera Lake and the surrounding rice fields waters are subjected to very heavy loads of sewage and toxic industrial residues (including heavy metals) from the many urban and wastewaters in this area. In previous reports the authors studied the toxicity and accumulation of cadmium on Procambarus clarkii of Albufera Lake. This crayfish shows a high resistance to cadmium and a great accumulation rate of this metal in several tissues, including midgut gland. Since Procambarus clarkii shows a high resistance to cadmium, the presence of cadmium binding proteins (Cd-BP) in midgut gland of these crayfish would be expected. This report describes results on the characterization of Cd-BPs obtained from cadmium exposed crayfish Procambarus clarkii, demonstrating their presence in this freshwater crayfish.

  14. Bioaccumulation of lead nitrate in freshwater crayfish (Astacus leptodactylus) tissues under aquaculture conditions.

    Science.gov (United States)

    Naghshbandi, N; Zare, S; Heidari, R; Soleimani Palcheglu, S

    2007-09-15

    The aim of this research was to evaluate the amount of lead in the tissue of Astacus leptodactylus especially in their muscle which the consumed part of their body. In this study the crayfish was exposed to intermediate concentration of lead nitrate (500 microg L(-1)) for periods up to 3 weeks. In the first, second and third weeks bioaccumulation in various tissues was under investigation. The data of toxicological analysis obtained by the method of atomic absorption revealed that the levels of bioaccumulation of metal are different in various tissues of this crayfish. The accumulation of the lead in gills was the highest and in muscles was lowest degree. The amount of heavy metals in the tissues of crayfish was as follow. Gills>exoskeleton>hepatopancreas (digestive glands)>digestive tract>green gland>testis and ovary>muscles.

  15. Differences in aggression, activity and boldness between native and introduced populations of an invasive crayfish

    Science.gov (United States)

    Pintor, L.M.; Sih, A.; Bauer, M.L.

    2008-01-01

    Aggressiveness, along with foraging voracity and boldness, are key behavioral mechanisms underlying the competitive displacement and invasion success of exotic species. However, do aggressiveness, voracity and boldness of the invader depend on the presence of an ecologically similar native competitor in the invaded community? We conducted four behavioral assays to compare aggression, foraging voracity, threat response and boldness to forage under predation risk of multiple populations of exotic signal crayfish Pacifastacus leniusculus across its native and invaded range with and without a native congener, the Shasta crayfish P. fortis. We predicted that signal crayfish from the invaded range and sympatric with a native congener (IRS) should be more aggressive to outcompete a close competitor than populations from the native range (NR) or invaded range and allopatric to a native congener (IRA). Furthermore, we predicted that IRS populations of signal crayfish should be more voracious, but less bold to forage under predation risk since native predators and prey likely possess appropriate behavioral responses to the invader. Contrary to our predictions, results indicated that IRA signal crayfish were more aggressive towards conspecifics and more voracious and active foragers, yet also bolder to forage under predation risk in comparison to NR and IRS populations, which did not differ in behavior. Higher aggression/voracity/ boldness was positively correlated with prey consumption rates, and hence potential impacts on prey. We suggest that the positive correlations between aggression/voracity/boldness are the result of an overall aggression syndrome. Results of stream surveys indicated that IRA streams have significantly lower prey biomass than in IRS streams, which may drive invading signal crayfish to be more aggressive/voracious/bold to acquire resources to establish a population. ?? 2008 The Authors.

  16. Effects of Different Social and Environmental Conditions on Established Dominance Relationships in Crayfish.

    Science.gov (United States)

    Herberholz, Jens; Swierzbinski, Matthew E; Birke, Juliane M

    2016-04-01

    Like most social animals, crayfish readily form dominance relationships and linear social hierarchies when competing for limited resources. Competition often entails dyadic aggressive interactions, from which one animal emerges as the dominant and one as the subordinate. Once dominance relationships are formed, they typically remain stable for extended periods of time; thus, access to future resources is divided unequally among conspecifics. We previously showed that firmly established dominance relationships in juvenile crayfish can be disrupted by briefly adding a larger conspecific to the original pair. This finding suggested that the stability of social relationships in crayfish was highly context-dependent and more transient than previously assumed. We now report results that further identify the mechanisms underlying the destabilization of crayfish dominance relationships. We found that rank orders remained stable when conspecifics of smaller or equal size were added to the original pair, suggesting that both dominant and subordinate must be defeated by a larger crayfish in order to destabilize dominance relationships. We also found that dominance relationships remained stable when both members of the original pair were defeated by larger conspecifics in the absence of their original opponent. This showed that dominance relationships are not destabilized unless both animals experience defeat together. Lastly, we found that dominance relationships of pairs were successfully disrupted by larger intruders, although with reduced magnitude, after all chemical cues associated with earlier agonistic experiences were eliminated. These findings provide important new insights into the contextual features that regulate the stability of social dominance relationships in crayfish and probably in other species as well. © 2016 Marine Biological Laboratory.

  17. Calcium transport mechanism in molting crayfish revealed by microanalysis

    International Nuclear Information System (INIS)

    Mizuhira, V.; Ueno, M.

    1983-01-01

    Crayfish provide a good model in which to study the transport mechanism of Ca ions. During the molting stage, decalcified Ca ions are transferred into the blood and accumulate in the gastrolith epithelium, after which a gastrolith is formed on the surface of the epithelium. The gastrolith is dissolved in the stomach after molting, and the Ca is reabsorbed and redistributed throughout the newly formed exoskeleton. We studied the mechanism of Ca transport by cytochemical precipitation of Ca ions and by electron microanalysis, including X-ray microanalysis (EDX) and electron energy-loss spectroscopy (EELS), with a computer. In EDX analysis, the fine precipitates of K-antimonate in the gastrolith mitochondria clearly defined Ca with antimony; we also observed a large amount of Ca-oxalate in the mitochondria, and Ca-K X-ray pulses were clearly defined. Ca-K X-rays were also detected from fresh freeze-substituted mitochondria. Finally, we succeeded in taking a Ca-L EELS image from the mitochondria of fresh freeze-substituted thin sections. Only a very small amount of Ca was detected from the cell membrane and other organelles. Ca-adenosine triphosphatase (ATPase) and Mg-ATPase activity was also very clearly demonstrated in the mitochondria. These enzymes may play an important role in Ca metabolism

  18. Response Function of the Crayfish Caudal Photoreceptor to Hydrodynamic Stimuli

    Science.gov (United States)

    Breite, Sally; Bahar, Sonya; Neiman, Alexander; Moss, Frank

    2002-03-01

    In its abdominal 6th ganglion the crayfish houses 2 light-sensitive neurons (caudal photoreceptors, or CPRs). It is known that these neurons work in tandem with a mechanosensory system of tiny hairs spread across the tailfan, which make synaptic contact with the photoreceptors. A stochastic resonance effect has been shown in this system in which light enhances the transduction of a weak, periodic mechanosensory (hydrodynamic) stimulus. It is not known, however, whether an optimal response from the CPR is induced by a single sine wave cycle or some other waveform. We have experimentally investigated this favorable waveform by driving a tailfan preparation with mechanical 10 Hz correlated Ornstein-Uhlenbeck noise and calculating the response function from the spike-triggered average of the applied noise waveform. We will discuss differences in the shape of the optimal waveform under dark and light conditions, as well as what seems to be a noticeable difference in the magnitude of the animals' response to a noisy stimulus in comparison with a periodic stimulus.

  19. Effect of calcium on excitatory neuromuscular transmission in the crayfish

    Science.gov (United States)

    Bracho, H.; Orkand, R. K.

    1970-01-01

    1. The effects of varying the external Ca concentration from 1·8 to 30 mM/l. (⅛-2 times normal) have been studied at the in vitro crayfish excitatory neuromuscular junction. Electrophysiological techniques were used to record transmembrane junctional potentials from muscle fibres and extracellular junctional currents from the vicinity of nerve terminals. 2. The excitatory junctional potential amplitude was proportional to [Ca]0n, where n varied between 0·68 and 0·94 (mean 0·82) when [Ca]0 was varied from 1·8 to 15 mM/l. 3. The increase in junctional potential amplitude on raising [Ca]0 resulted primarily from an increase in the average number of quanta of excitatory transmitter released from the presynaptic nerve terminal by the nerve impulse. 4. The size of the quanta, synaptic delay, presynaptic potential and electrical properties of the muscle membrane were little affected by changes in calcium concentration in the range studied. PMID:5498460

  20. REDUCING THE THREAT TO CONTROL INVASIVE SIGNAL CRAYFISH REDUCING: THE POTENTIAL USE OF PHEROMONES

    Directory of Open Access Journals (Sweden)

    STEBBING P. D.

    2003-04-01

    Full Text Available The need for an effective method of controlling invasive species of crayfish is of utmost importance given the plight of Europe’s native crayfish species. Many techniques have been applied to the growing problem with little success. Pheromones have been used to control terrestrial insect pests for a number of years with many success stories. The concept of applying pheromone control methods to the aquatic environment is by no means new, but has not been previously developed. This paper discusses the preliminary results from field trials testing traps baited with Pacifastacus leniusculus pheromones, and the potential application of the pheromones in controlling P. leniusculus populations.

  1. Photodynamic damage of glial cells in crayfish ventral nerve cord

    Science.gov (United States)

    Kolosov, M. S.; Duz, E.; Uzdensky, A. B.

    2011-03-01

    Photodynamic therapy (PDT) is a promising method for treatment of brain tumors, the most of which are of glial origin. In the present work we studied PDT-mediated injury of glial cells in nerve tissue, specifically, in abdominal connectives in the crayfish ventral nerve cord. The preparation was photosensitized with alumophthalocyanine Photosens and irradiated 30 min with the diode laser (670 nm, 0.1 or 0.15 W/cm2). After following incubation in the darkness during 1- 10 hours it was fluorochromed with Hoechst 33342 and propidium iodide to reveal nuclei of living, necrotic and apoptotic cells. The chain-like location of the glial nuclei allowed visualization of those enveloping giant axons and blood vessels. The level of glial necrosis in control preparations was about 2-5 %. Apoptosis was not observed in control preparations. PDT significantly increased necrosis of glial cells to 52 or 67 % just after irradiation with 0.1 or 0.15 W/cm2, respectively. Apoptosis of glial cells was observed only at 10 hours after light exposure. Upper layers of the glial envelope of the connectives were injured stronger comparing to deep ones: the level of glial necrosis decreased from 100 to 30 % upon moving from the connective surface to the plane of the giant axon inside the connective. Survival of glial cells was also high in the vicinity of blood vessels. One can suggest that giant axons and blood vessels protect neighboring glial cells from photodynamic damage. The mechanism of such protective action remains to be elucidated.

  2. Genetic characterization of Western European noble crayfish populations (Astacus astacus) for advanced conservation management strategies

    NARCIS (Netherlands)

    Schrimpf, A.; Piscione, M.; Cammaerts, R.; Collas, M.; Herman, D.; Jung, A.; Ottburg, F.; Roessink, I.; Rollin, X.; Schulz, R.; Theissinger, K.

    2017-01-01

    One central goal of conservation biology is to conserve the genetic diversity of species in order to protect their adaptive potential. The main objective of this study was to identify management units (MUs) for the threatened noble crayfish (Astacus astacus) in Western Europe by utilizing

  3. ANNUAL ACTIVITY OF THE NOBLE CRAYFISH (ASTACUS ASTACUS IN THE ORLJAVA RIVER (CROATIA

    Directory of Open Access Journals (Sweden)

    FALLER M.

    2006-07-01

    Full Text Available We studied the annual activity of the noble crayfish (Astacus astacus at three sites along the Orljava River, in the continental part of Croatia, between August 2003 and September 2004. Each site represented the typical characteristics of the upper, middle and lower section of the river (5, 24 and 37 km from the spring, respectively. The biggest population size was recorded on the most upstream site, with greatest structural variability of bottom, high biotic index, and the lowest mean water temperature. Males dominated in catch during the whole research period (total sex ratio was 1.77 males: 1 female. The number of caught crayfish fluctuated during the year and their activity was positively correlated with the water temperature. The crayfish catch within the two downstream sites was dramatically lower in the autumn 2004 then the year before. No obvious reason could be found; therefore we concluded that this was probably result of natural fluctuations in population. Males were significantly longer than females on all three sites. Males and females had similar percentages of injuries, mainly on claws and antennae. Crayfish were active during the whole year, even when water temperature was just 1°C. Phases of life cycle (moulting, active cement glands, mating, hatchlings occurred a month later in our population than in the Northern Europe populations, probably as a consequence of differences in the climate.

  4. Fishes, mussels, crayfishes, and aquatic habitats of the Hoosier-Shawnee ecological assessment area

    Science.gov (United States)

    M. Burr Brooks; Justin T. Sipiorski; Matthew R. Thomas; Kevin S. Cummings; Christopher A. Taylor

    2004-01-01

    The Hoosier-Shawnee Ecological Assessment Area, part of the Coastal Plain and Interior Low Plateau physiographic provinces, includes 194 native fish species, 76 native mussel species, and 34 native crayfish species. Five of the subregions (e.g., Mississippi Embayment) that make up the assessment area were recently ranked as either globally or bioregionally outstanding...

  5. A global review of freshwater crayfish temperature tolerance, preference, and optimal growth

    Science.gov (United States)

    Westhoff, Jacob T.; Rosenberger, Amanda E.

    2016-01-01

    Conservation efforts, environmental planning, and management must account for ongoing ecosystem alteration due to a changing climate, introduced species, and shifting land use. This type of management can be facilitated by an understanding of the thermal ecology of aquatic organisms. However, information on thermal ecology for entire taxonomic groups is rarely compiled or summarized, and reviews of the science can facilitate its advancement. Crayfish are one of the most globally threatened taxa, and ongoing declines and extirpation could have serious consequences on aquatic ecosystem function due to their significant biomass and ecosystem roles. Our goal was to review the literature on thermal ecology for freshwater crayfish worldwide, with emphasis on studies that estimated temperature tolerance, temperature preference, or optimal growth. We also explored relationships between temperature metrics and species distributions. We located 56 studies containing information for at least one of those three metrics, which covered approximately 6 % of extant crayfish species worldwide. Information on one or more metrics existed for all 3 genera of Astacidae, 4 of the 12 genera of Cambaridae, and 3 of the 15 genera of Parastacidae. Investigations employed numerous methodological approaches for estimating these parameters, which restricts comparisons among and within species. The only statistically significant relationship we observed between a temperature metric and species range was a negative linear relationship between absolute latitude and optimal growth temperature. We recommend expansion of studies examining the thermal ecology of freshwater crayfish and identify and discuss methodological approaches that can improve standardization and comparability among studies.

  6. Interactions between crayfish, benthic invertebrates, macrophyte roots and sediment in a littoral zone

    Czech Academy of Sciences Publication Activity Database

    Ságová-Marečková, Markéta

    2002-01-01

    Roč. 155, č. 4 (2002), s. 645-665 ISSN 0003-9136 Grant - others:GA the Center for Limnology of the UW-Madison(XX) BSR8514330 Institutional research plan: CEZ:AV0Z5020903 Keywords : predation * food * crayfish Subject RIV: EE - Microbiology, Virology Impact factor: 1.195, year: 2002

  7. Effects of chronic cocaine, morphine and methamphetamine on the mobility, immobility and stereotyped behaviors in crayfish.

    Science.gov (United States)

    Imeh-Nathaniel, Adebobola; Rincon, Natalia; Orfanakos, Vasiliki Bessie; Brechtel, Leanne; Wormack, Leah; Richardson, Erika; Huber, Robert; Nathaniel, Thomas I

    2017-08-14

    The worth of crayfish as a model system for studies of addiction was not previously recognized because a drug-reward phenomenon had not been documented in this model system. In our previous experiments, we demonstrate that the crayfish natural reward pathways are sensitive to human drugs of abuse. This finding supports crayfish as a suitable model to characterize specific behaviors that are relevant in drug addiction research, and the current study builds on our previous findings. The aim of the present study was to investigate unconditioned neurobehavioral effects of repeated treatment regimens using cocaine, morphine, and methamphetamine for three consecutive days. We analyzed mobility, immobility and characterized stereotypic behaviors following intracardial infusions of 2.0μg/g or 10.0μg/g doses of cocaine, morphine, and methamphetamine for three days. The results showed that systemic cocaine, morphine, and methamphetamine increased mobility at a low dose of 2.0μg/g more effectively than a high dose of 10.0μg/g, while simultaneously showing that the high dose exerted a more prominent effect in increasing immobility. Moreover, systemic cocaine, morphine, and methamphetamine injections have discerning effects towards a group of defined unconditioned stereotyped behavioral patterns associated with each drug, rather than a shared universal behavioral effect. These findings provide insight into the behavioral and pharmacological basis responsible for the unconditioned effects of these drugs in crayfish. Copyright © 2017. Published by Elsevier B.V.

  8. A multigear protocol for sampling crayfish assemblages in Gulf of Mexico coastal streams

    Science.gov (United States)

    William R. Budnick; William E. Kelso; Susan B. Adams; Michael D. Kaller

    2018-01-01

    Identifying an effective protocol for sampling crayfish in streams that vary in habitat and physical/chemical characteristics has proven problematic. We evaluated an active, combined-gear (backpack electrofishing and dipnetting) sampling protocol in 20 Coastal Plain streams in Louisiana. Using generalized linear models and rarefaction curves, we evaluated environmental...

  9. Cadmium accumulation in the crayfish, Procambarus clarkii, using graphite furnace atomic absorption spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Diaz-Mayans, J.; Hernandez, F.; Medina, J.; Del Ramo, J.; Torreblanca, A.

    1986-11-01

    Lake Albufera and the surrounding rice-field waters are being subject to very heavy loads of sewage and toxic industrial residues (including heavy metals and pesticides) from the many urban and wastewaters in this area. The American red crayfish Procambarus clarkii is native to the Louisiana marshes (USA). In 1978, the crayfish appeared in Lake Albufera near Valencia (Spain), and presently, without adequate sanitary controls, the crayfish is being fished commercially for human consumption. In view of this interest, it is important to have accurate information on concentrations of cadmium in natural waters and cadmium levels of tissues of freshwaters animals used as human food, as well as the accumulation rates of this metal in this animal. In the present study, the authors investigated the accumulation of cadmium in several tissues of the red crayfish, P clarkii (Girard) from Lake Albufera following cadmium exposure. Determinations of cadmium were made by flameless atomic absorption spectroscopy and the standard additions method. Digestion of samples was made by wet ashing in open flasks with concentrated HNO/sub 3/ at 80-90/sup 0/C.

  10. Determination of lead in treated crayfish Procambarus clarkii: accumulation in different tissues

    Energy Technology Data Exchange (ETDEWEB)

    Pastor, A.; Medina, J.; Del Ramo, J.; Torreblanca, A.; Diaz-Mayans, J.; Hernandez, F.

    1988-09-01

    The continual loading of trace metals into our environment represents a water pollution problem due to their toxic effects on aquatic biota. In addition, metal ions can be incorporated into food chains and concentrated by aquatic organisms to a level that affects their physiological state. There are several investigations on the toxic effects and bioaccumulation of lead in fishes, molluscs, and crustaceans. Lake Albufera (Valencia, Spain) and the surrounding rice-field waters are subjected to large loads of sewage and toxic industrial residues (including heavy metals) from many urban wastewaters in the area. In 1978, the American red crayfish Procambarus clarkii (Girard) appeared in Lake Albufera. The crayfish have reached a high density producing ecological and agricultural economic problems in rice crops. The crayfish is being fished commercially for human consumption without adequate protection to human health. The purpose of the present study was to investigate the accumulation of lead in tissues of the crayfish P. clarkii following short term lead exposure at several sublethal concentrations. The gills, midgut glands, antennal glands and muscle were analyzed by atomic absorption spectrophotometry.

  11. Who is the boss? Individual recognition memory and social hierarchy formation in crayfish.

    Science.gov (United States)

    Jiménez-Morales, Nayeli; Mendoza-Ángeles, Karina; Porras-Villalobos, Mercedes; Ibarra-Coronado, Elizabeth; Roldán-Roldán, Gabriel; Hernández-Falcón, Jesús

    2018-01-01

    Under laboratory conditions, crayfish establish hierarchical orders through agonistic encounters whose outcome defines the dominant one and one, or more, submissive animals. These agonistic encounters are ritualistic, based on threats, pushes, attacks, grabs, and avoidance behaviors that include retreats and escape responses. Agonistic behavior in a triad of unfamiliar, size-matched animals is intense on the first day of social interaction and the intensity fades on daily repetitions. The dominant animal keeps its status for long periods, and the submissive ones seem to remember 'who the boss is'. It has been assumed that animals remember and recognize their hierarchical status by urine signals, but the putative substance mediating this recognition has not been reported. The aim of this work was to characterize this hierarchical recognition memory. Triads of unfamiliar crayfish (male animals, size and weight-matched) were faced during standardized agonistic protocols for five consecutive days to analyze memory acquisition dynamics (Experiment 1). In Experiment 2, dominant crayfish were shifted among triads to disclose whether hierarchy depended upon individual recognition memory or recognition of status. The maintenance of the hierarchical structure without behavioral reinforcement was assessed by immobilizing the dominant animal during eleven daily agonistic encounters, and considering any shift in the dominance order (Experiment 3). Standard amnesic treatments (anisomycin, scopolamine or cold-anesthesia) were given to all members of the triads immediately after the first interaction session to prevent individual recognition memory consolidation and evaluate its effect on the hierarchical order (Experiment 4). Acquisition of hierarchical recognition occurs at the first agonistic encounter and agonistic behavior gradually diminishes in the following days; animals keep their hierarchical order despite the inability of the dominant crayfish to attack the submissive

  12. ECOLOGICAL CHARACTERISATION OF STREAMS IN TUSCANY (ITALY FOR THE MANAGEMENT OF THE THREATENED CRAYFISH AUSTROPOTAMOBIUS PALLIPES COMPLEX

    Directory of Open Access Journals (Sweden)

    RENAI B.

    2006-01-01

    Full Text Available Any initiative aimed at the management of a threatened species needs a good knowledge of its environmental requirements. Aims of this study were to individuate suitable areas for the reintroduction of crayfish species belonging to the Austropotamobius pallipes complex and to evaluate the causes of the local extinction in Tuscany (Italy of some populations. Between May 2003 and September 2004, we collected ecological data from 19 streams of 4 catchments, 9 watercourses where crayfish were present (WI and 10 where they were present in the recent past and absent now (WO, and we compared them. Multivariate analyses were performed using chemico-physical and biotic parameters to examine the relationships between their values and the presence of crayfish. The results did not allow us to find significant differences between the two categories of streams, suggesting their suitability for crayfish reintroduction.

  13. Enzymatic production of N-acetyl-d-glucosamine from crayfish shell wastes pretreated via high pressure homogenization.

    Science.gov (United States)

    Wei, Guoguang; Zhang, Alei; Chen, Kequan; Ouyang, Pingkai

    2017-09-01

    This study presents an efficient pretreatment of crayfish shell using high pressure homogenization that enables N-acetyl-d-glucosamine (GlcNAc) production by chitinase. Firstly, the chitinase from Serratia proteamaculans NJ303 was screened for its ability to degrade crayfish shell and produce GlcNAc as the sole product. Secondly, high pressure homogenization, which caused the crayfish shell to adopt a fluffy netted structure that was characterized by Scanning electron microscope (SEM), Fourier transform infrared spectrometer (FT-IR), X-ray diffraction (XRD), was evaluated as the best pretreatment method. In addition, the optimal conditions of high pressure homogenization of crayfish shell were determined to be five cycles at a pressure of 400bar, which achieved a yield of 3.9g/L of GlcNAc from 25g/L of crayfish shell in a batch enzymatic reaction over 1.5h. The results showed high pressure homogenization might be an efficient method for direct utilization of crayfish shell for enzymatic production of GlcNAc. Copyright © 2017 Elsevier Ltd. All rights reserved.

  14. A SURVEY OF THE WHITE-CLAWED CRAYFISH,AUSTROPOTAMOBIUS PALLIPES (LEREBOULLET, AND OF WATERQUALITY IN TWO CATCHMENTS OF EASTERN IRELAND.

    Directory of Open Access Journals (Sweden)

    DEMERS A.

    2002-07-01

    Full Text Available The white-clawed crayfish, Austropotamobius pallipes (Lereboullet, is the only crayfish species found in Ireland. Because of the prohibition on importation of exotic species of crayfish onto the island and of its relatively clean rivers up to now, Ireland has kept an abundant population of crayfish. A survey was conducted in the catchments of the Liffey and Boyne rivers, in eastern Ireland to assess water quality and to sample crayfish populations. The aim of the study was to evaluate the water quality requirements of the white-clawed crayfish in Ireland. Baited traps and nets were used to sample crayfish while water quality was measured with biological indices calculated from samples of macroinvertebrates. Distribution of this crayfish species is patchy in the Liffey catchment and seems to be related to factors such as soil types and water quality. They were not found in the downstream part of the river Liffey possibly due to poor water quality. In the Boyne catchment, no crayfish were found in most of the catchment. They were only present in the Kells Blackwater subcatchment. This may be due to an earlier outbreak of the fungal plague caused by Aphanomyces astaci. The disease was discovered in lakes at the top of some of the tributaries of the Boyne in 1987 and it probably spread from there through the whole catchment.

  15. Water chemistry and endangered white-clawed Crayfish: a literature review and field study of water chemistry association in Austropotamobius pallipes

    Directory of Open Access Journals (Sweden)

    Haddaway N.R.

    2015-01-01

    Full Text Available Populations of the endangered white-clawed crayfish (Austropotamobius pallipes have rapidly declined in distribution and density in recent decades as a result of invasive crayfish, disease and habitat degradation. The species is thought to be particularly sensitive to water chemistry, and has been proposed as a bio-indicator of water quality. Here we detail the results of a systematic review of the literature regarding the chemistry of waterbodies inhabited by white-clawed crayfish, along with a wide-scale field study of the chemistry of crayfish-inhabited waterbodies in the UK. We use these data to examine potentially significant variables influencing crayfish distribution. Several variables appear to have thresholds that affect crayfish distribution; crayfish presence was associated with high dissolved oxygen, low conductivity, ammonium, sodium, and phosphate, and to a lesser extent low sulphate, nitrate, and total suspended solids. Some variables (magnesium, potassium, sodium, sulphate, nitrate, and total suspended solids may be tolerated at moderate to high concentrations in isolation (indicated by the presence of some populations in high levels of these variables, but suites of chemical conditions may act synergistically in situ and must be considered together. Recent efforts to conserve white-clawed crayfish have included relocations to Ark Sites; novel protected habitats with reduced risk of the introduction of disease, invasive crayfish and habitat degradation. We use our findings to propose the first detailed guidelines for common water chemistry variables of potential Ark Sites for the conservation of the species throughout its European range.

  16. First record of the invasive Australian redclaw crayfish Cherax quadricarinatus (von Martens, 1868 in the Crocodile River, Kruger National Park, South Africa

    Directory of Open Access Journals (Sweden)

    Robin M. Petersen

    2017-03-01

    Full Text Available The redclaw crayfish Cherax quadricarinatus (von Martens, 1868, a robust freshwater crayfish native to Australia and Papua New Guinea, has now been recorded from the Kruger National Park (KNP. Previously absent from the Crocodile River, SAN Parks received a report in February 2016 of redclaw crayfish below the Van Graan Dam on the border of the KNP. Here, we provide evidence of the presence of redclaw crayfish in the Crocodile River. A better understanding of the redclaw crayfish distribution, habitat preferences, rate of spread and impacts on the local aquatic ecosystems in the Crocodile River is urgently required to develop mitigation strategies that minimise the spread of this invasive crayfish in the KNP and the Komati Catchment. The negative impacts of global crayfish introductions justify efforts to discourage further introductions and prevent their secondary spread. Conservation implications: A better understanding of the redclaw crayfish distribution, habitat preferences, rate of spread and impacts on the local aquatic ecosystems in the Crocodile River is urgently required to develop mitigation strategies that minimise the spread of this invasive crayfish in the Kruger National Park and the Komati Catchment.

  17. Nutritional treatment of cancer cachexia in rats. Use of a diet formulated with a crayfish enzymatic extract.

    Science.gov (United States)

    Cremades, Olga; Parrado, Juan; Jover, María; Collantes de Terán, Laura; Gutiérrez, Juan Francisco; Bautista Palomas, Juan D

    2007-09-01

    Terminal cancer-associated cachexia, characterized by a marked weight loss, anorexia, asthenia and anemia, is usually associated with a malnutrition status. To investigate whether a diet formulated with a crayfish enzymatic extract, enriched in essential amino acids, omega-3 fatty acids, and astaxanthin, would be effective for the treatment of cancer-associated cachexias, by decreasing mortality and morbidity rates in cachectic rats and/or improving survival. Two types of diet were used: a standard diet and one formulated with crayfish enzymatic extract. Rats were divided into two groups (24 animals per group): one without tumor (T-) and the other with tumor (T+) (AH-130 Yoshida ascites hepatoma). Each group was further divided into two subgroups (12 animals per subgroup). Two subgroups (T-(standard) and T+(standard)) were fed the standard diet and the other two (T-(CFEE) and T+(CFEE)) the crayfish enzymatic extract one for four weeks, after which different tissue and plasma parameters were studied. The implantation of the tumor resulted in a considerable loss of muscle and adipose tissue mass in both groups, but the loss of muscle and fat was lower in the group fed the crayfish enzymatic extract diet. There was also a concomitant increase in the plasma concentration of TNF-alpha, although the increase was smaller in the crayfish enzymatic extract-treated group. This study shows that although the treatment of cachetic rats with the crayfish enzymatic extract diet did not revert the cachexia, it increased survival (57.1% vs. 25.9% in the group treated with crayfish enzymatic extract and standard diets, respectively) and meliorated the cachexia symptoms--anorexia and body mass loss (muscle and adipose tissue).

  18. ANNUAL ACTIVITY OF THE NOBLE CRAYFISH (ASTACUS ASTACUS) IN THE ORLJAVA RIVER (CROATIA)

    OpenAIRE

    FALLER M.; MAGUIRE I.; KLOBUČAR G.

    2006-01-01

    We studied the annual activity of the noble crayfish (Astacus astacus) at three sites along the Orljava River, in the continental part of Croatia, between August 2003 and September 2004. Each site represented the typical characteristics of the upper, middle and lower section of the river (5, 24 and 37 km from the spring, respectively). The biggest population size was recorded on the most upstream site, with greatest structural variability of bottom, high biotic index, and the lowest mean wate...

  19. Histological analysis of thelohaniasis in white-clawed crayfish Austropotamobius pallipes complex

    Directory of Open Access Journals (Sweden)

    Quaglio F.

    2011-09-01

    Full Text Available From 2004 to 2006, a parasitological survey aimed at the detection of the microsporidian parasite Thelohania contejeani Henneguy was carried out on 177 wild white-clawed crayfish (Austropotamobius pallipes complex captured in six streams and rivers of the province of Belluno in north-eastern Italy. Microscopical examination of the skeletal muscles, and histological analysis applying different histochemical stains to full transverse and sagittal sections of the cephalothorax and abdomen were carried out. Transmission electron microscopy (TEM was also conducted on the parasites recovered during the survey. Out of 177 crayfish examined, Thelohania contejeani (Microsporidia, Thelohaniidae was present in only one crayfish from the Vena d’oro creek. The parasite was detected in the skeletal muscles in several developmental stages, including mature spores, which represented the most common stage recovered. Sporophorous vesicles were also present. Histological examination revealed that the fibres of the skeletal, cardiac and intestinal muscles were filled with spores. Melanin infiltrations were focally present in the infected striated muscles. The gill phagocytic nephrocytes were engulfed by small masses of spores. Among the staining techniques applied, Crossman’s trichrome stain represented the most effective method of detecting T. contejeani.

  20. Comparative Ultrastructure and Carbohydrate Composition of Gastroliths from Astacidae, Cambaridae and Parastacidae Freshwater Crayfish (Crustacea, Decapoda

    Directory of Open Access Journals (Sweden)

    Gérard Alcaraz

    2012-12-01

    Full Text Available Crustaceans have to cyclically replace their rigid exoskeleton in order to grow. Most of them harden this skeleton by a calcification process. Some decapods (land crabs, lobsters and crayfish elaborate calcium storage structures as a reservoir of calcium ions in their stomach wall, as so-called gastroliths. For a better understanding of the cyclic elaboration of these calcium deposits, we studied the ultrastructure of gastroliths from freshwater crayfish by using a combination of microscopic and physical techniques. Because sugars are also molecules putatively involved in the elaboration process of these biomineralizations, we also determined their carbohydrate composition. This study was performed in a comparative perspective on crayfish species belonging to the infra-order Astacidea (Decapoda, Malacostraca: three species from the Astacoidea superfamily and one species from the Parastacoidea superfamily. We observed that all the gastroliths exhibit a similar dense network of protein-chitin fibers, from macro- to nanoscale, within which calcium is precipitated as amorphous calcium carbonate. Nevertheless, they are not very similar at the molecular level, notably as regards their carbohydrate composition. Besides glucosamine, the basic carbohydrate component of chitin, we evidenced the presence of other sugars, some of which are species-specific like rhamnose and galacturonic acid whereas xylose and mannose could be linked to proteoglycan components.

  1. Predatory functional response and prey choice identify predation differences between native/invasive and parasitised/unparasitised crayfish.

    Science.gov (United States)

    Haddaway, Neal R; Wilcox, Ruth H; Heptonstall, Rachael E A; Griffiths, Hannah M; Mortimer, Robert J G; Christmas, Martin; Dunn, Alison M

    2012-01-01

    Invasive predators may change the structure of invaded communities through predation and competition with native species. In Europe, the invasive signal crayfish Pacifastacus leniusculus is excluding the native white clawed crayfish Austropotamobius pallipes. This study compared the predatory functional responses and prey choice of native and invasive crayfish and measured impacts of parasitism on the predatory strength of the native species. Invasive crayfish showed a higher (>10%) prey (Gammarus pulex) intake rate than (size matched) natives, reflecting a shorter (16%) prey handling time. The native crayfish also showed greater selection for crustacean prey over molluscs and bloodworm, whereas the invasive species was a more generalist predator. A. pallipes parasitised by the microsporidian parasite Thelohania contejeani showed a 30% reduction in prey intake. We suggest that this results from parasite-induced muscle damage, and this is supported by a reduced (38%) attack rate and increased (30%) prey handling time. Our results indicate that the per capita (i.e., functional response) difference between the species may contribute to success of the invader and extinction of the native species, as well as decreased biodiversity and biomass in invaded rivers. In addition, the reduced predatory strength of parasitized natives may impair their competitive abilities, facilitating exclusion by the invader.

  2. It takes time to see the menu from the body: an experiment on stable isotope composition in freshwater crayfishes

    Directory of Open Access Journals (Sweden)

    Jussila J.

    2015-01-01

    Full Text Available For many applications and ecological studies in which wild individuals are brought to laboratory it would be essential to know accurately how fast novel diet is reflected in composition of different tissues. To study the effects of two different diets on the stable isotope composition of freshwater crayfish muscle and hemolymph, we conducted a three month experiment on noble crayfish (Astacus astacus and signal crayfish (Pacifastacus leniusculus by feeding them sweet corn (Zea mays or Baltic herring (Clupea harengus membras as novel food. During the experiment, the crayfish were given 0.4 g of selected food daily and the amount consumed was recorded. The samples for the stable isotope analyses were taken at the commencement of the experiment (initial control and three times (hemolymph or twice (muscle tissue during the experiment. We found that stable isotope changes can be similarly, and rather slowly, detected from muscle tissue and hemolymph under studied conditions. Hemolymph sampling, being non-lethal, can be recommended as a practical sampling method. Our results confirm earlier reports according to which diet changes reflect to crayfish isotope ratios slowly implying that isotope ratios indicate long-term diet.

  3. Comparative study of freshwater crayfish, Cherax spp. (crustaceae: decapoda: parastacidae) from Papua, Indonesia based on length-weight analysis

    Science.gov (United States)

    Hamidah, H.; Abinawanto, Bowolaksono, A.

    2017-07-01

    The freshwater crayfish is one of the most important fish species as the protein resources. Lake and rivers are the habitat of crayfish in Papua. Morphological characters of crayfish, such as color, total body lengths (L) and body weight (W) were influenced by the habitat. The purpose of the study, therefore, was to compare the total body length and body weight as well as the unique color of crayfish from Uter lake (Atinjo district), Seremuk river (Haha village), Baliem river (Pike village; Hubukiak district, Jayawijaya), and Baliem river (Wesaput village; Wesaput district). Length-weight (body length; LB versus wet weight; WWT) relationships were determined for male and female crayfish (Cherax spp.) The length-weight relationships of total individuals was W = 0,022215.L3,159. This regression differed significantly (R2 = 97.5 %) between locations. Both males and females exhibited positive allometric growth as statistical difference was observed in the mean of the wet weight and body length between males and females. Besides, Canonical function was subjected to determine population distribution based on length-weight data.

  4. COMPARISON AMONG PRE-GELATINIZED STARCHES OF DIFFERENT BOTANICAL ORIGINS USED IN NOBLE CRAYFISH ASTACUS ASTACUS DIETS

    Directory of Open Access Journals (Sweden)

    D’AGARO E.

    2006-01-01

    Full Text Available The objective of the present experiment was to compare the biological value and the binding functionality of four pre-gelatinized starches (wheat, diet 1; waxy maize, diet 2; maize, diet 3 and potato, diet 4 used in crayfish diets. 360 juvenile of A. astacus (initial b.w.: 0.70 ± 0.15 g were cultured in 12 tanks for 43d. Growth performance were significantly higher in crayfish fed diets containing wheat and waxy maize compared to those containing maize and potato pre-gelatinized starches. Disintegration in water and shear force tests of diets confirmed the superior binding capability of pre-gelatinized starches obtained from wheat and waxy maize. These results suggest that the pregelatinized wheat and waxy maize starches are the best choice for the production of diets for the noble crayfish.

  5. Can heat waves change the trophic role of the world's most invasive crayfish? Diet shifts in Procambarus clarkii.

    Science.gov (United States)

    Carreira, Bruno M; Segurado, Pedro; Laurila, Anssi; Rebelo, Rui

    2017-01-01

    In the Mediterranean basin, the globally increasing temperatures are expected to be accompanied by longer heat waves. Commonly assumed to benefit cold-limited invasive alien species, these climatic changes may also change their feeding preferences, especially in the case of omnivorous ectotherms. We investigated heat wave effects on diet choice, growth and energy reserves in the invasive red swamp crayfish, Procambarus clarkii. In laboratory experiments, we fed juvenile and adult crayfish on animal, plant or mixed diets and exposed them to a short or a long heat wave. We then measured crayfish survival, growth, body reserves and Fulton's condition index. Diet choices of the crayfish maintained on the mixed diet were estimated using stable isotopes (13C and 15N). The results suggest a decreased efficiency of carnivorous diets at higher temperatures, as juveniles fed on the animal diet were unable to maintain high growth rates in the long heat wave; and a decreased efficiency of herbivorous diets at lower temperatures, as juveniles in the cold accumulated less body reserves when fed on the plant diet. Heat wave treatments increased the assimilation of plant material, especially in juveniles, allowing them to sustain high growth rates in the long heat wave. Contrary to our expectations, crayfish performance decreased in the long heat wave, suggesting that Mediterranean summer heat waves may have negative effects on P. clarkii and that they are unlikely to boost its populations in this region. Although uncertain, it is possible that the greater assimilation of the plant diet resulted from changes in crayfish feeding preferences, raising the hypotheses that i) heat waves may change the predominant impacts of this keystone species and ii) that by altering species' trophic niches, climate change may alter the main impacts of invasive alien species.

  6. Fluoride bioaccumulation and toxic effects on the survival and behavior of the endangered white-clawed crayfish Austropotamobius pallipes (Lereboullet).

    Science.gov (United States)

    Aguirre-Sierra, Arantxa; Alonso, Alvaro; Camargo, Julio A

    2013-08-01

    Laboratory experiments were performed to examine the toxic effects of fluoride (F(-)) on the survival and behavior of white-clawed crayfish (Austropotamobius pallipes). Body fluoride contents (bioaccumulation) of test crayfish were also examined. No significant differences between male and female crayfish regarding mortality, escape (tail-flip) response, and fluoride bioaccumulation were detected. For mortality, 48-, 72-, 96-, 120-, 144-, 168-, and 192-h median lethal concentrations (LC50) were estimated to be 93.0, 55.3, 42.7, 36.5, 32.9, 30.6, and 28.9 mg F(-)/l, respectively. For the escape response, 48-, 72-, 96-, 120-, 144-, 168- and 192-h median effective concentrations (EC50) were estimated to be 18.4, 11.1, 8.6, 7.4, 6.7, 6.2 and 5.9 mg F(-)/l, respectively. Average food consumption in test crayfish tended to decrease with increasing water fluoride concentration with a 192-h lowest-observed effect concentration of 10.7 mg F(-)/l. These results indicate that the escape response was the most sensitive end point to fluoride toxicity followed by food consumption and mortality. Fluoride bioaccumulation in test crayfish increased with increasing water fluoride concentration and exposure time. The exoskeleton accumulated more fluoride than muscle. A comparison of the obtained results with previous data for other freshwater invertebrates shows that white-clawed crayfish are relatively tolerant to fluoride toxicity. We conclude that fluoride pollution in freshwater ecosystems should not be viewed as an important risk factor contributing to the catastrophic decrease of A. pallipes in many European countries. Our results indicate that fluoride bioaccumulation in A. pallipes might be used as a bioindicator of fluoride pollution in freshwater ecosystems where it is present.

  7. Can heat waves change the trophic role of the world's most invasive crayfish? Diet shifts in Procambarus clarkii.

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    Bruno M Carreira

    Full Text Available In the Mediterranean basin, the globally increasing temperatures are expected to be accompanied by longer heat waves. Commonly assumed to benefit cold-limited invasive alien species, these climatic changes may also change their feeding preferences, especially in the case of omnivorous ectotherms. We investigated heat wave effects on diet choice, growth and energy reserves in the invasive red swamp crayfish, Procambarus clarkii. In laboratory experiments, we fed juvenile and adult crayfish on animal, plant or mixed diets and exposed them to a short or a long heat wave. We then measured crayfish survival, growth, body reserves and Fulton's condition index. Diet choices of the crayfish maintained on the mixed diet were estimated using stable isotopes (13C and 15N. The results suggest a decreased efficiency of carnivorous diets at higher temperatures, as juveniles fed on the animal diet were unable to maintain high growth rates in the long heat wave; and a decreased efficiency of herbivorous diets at lower temperatures, as juveniles in the cold accumulated less body reserves when fed on the plant diet. Heat wave treatments increased the assimilation of plant material, especially in juveniles, allowing them to sustain high growth rates in the long heat wave. Contrary to our expectations, crayfish performance decreased in the long heat wave, suggesting that Mediterranean summer heat waves may have negative effects on P. clarkii and that they are unlikely to boost its populations in this region. Although uncertain, it is possible that the greater assimilation of the plant diet resulted from changes in crayfish feeding preferences, raising the hypotheses that i heat waves may change the predominant impacts of this keystone species and ii that by altering species' trophic niches, climate change may alter the main impacts of invasive alien species.

  8. Drug-sensitive reward in crayfish: an invertebrate model system for the study of SEEKING, reward, addiction, and withdrawal.

    Science.gov (United States)

    Huber, Robert; Panksepp, Jules B; Nathaniel, Thomas; Alcaro, Antonio; Panksepp, Jaak

    2011-10-01

    In mammals, rewarding properties of drugs depend on their capacity to activate appetitive motivational states. With the underlying mechanisms strongly conserved in evolution, invertebrates have recently emerged as a powerful new model in addiction research. In crayfish natural reward has proven surprisingly sensitive to human drugs of abuse, opening an unlikely avenue of research into the basic biological mechanisms of drug addiction. In a series of studies we first examined the presence of natural reward systems in crayfish, then characterized its sensitivity to a wide range of human drugs of abuse. A conditioned place preference (CPP) paradigm was used to demonstrate that crayfish seek out those environments that had previously been paired with the psychostimulants cocaine and amphetamine, and the opioid morphine. The administration of amphetamine exerted its effects at a number of sites, including the stimulation of circuits for active exploratory behaviors (i.e., SEEKING). A further study examined morphine-induced reward, extinction and reinstatement in crayfish. Repeated intra-circulatory infusions of morphine served as a reward when paired with distinct visual or tactile cues. Morphine-induced CPP was extinguished after repeated saline injections. Following this extinction phase, morphine-experienced crayfish were once again challenged with the drug. The priming injections of morphine reinstated CPP at all tested doses, suggesting that morphine-induced CPP is unrelenting. In an exploration of drug-associated behavioral sensitization in crayfish we concurrently mapped measures of locomotion and rewarding properties of morphine. Single and repeated intra-circulatory infusions of morphine resulted in persistent locomotory sensitization, even 5 days following the infusion. Moreover, a single dose of morphine was sufficient to induce long-term behavioral sensitization. CPP for morphine and context-dependent cues could not be disrupted over a drug free period of 5

  9. Histological changes and antioxidant enzyme activity in signal crayfish (Pacifastacus leniusculus) associated with sub-acute peracetic acid exposure.

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    Chupani, Latifeh; Zuskova, Eliska; Stara, Alzbeta; Velisek, Josef; Kouba, Antonin

    2016-01-01

    Peracetic acid (PAA) is a powerful disinfectant recently adopted as a therapeutic agent in aquaculture. A concentration of 10 mg L(-1) PAA effectively suppresses zoospores of Aphanomyces astaci, the agent of crayfish plague. To aid in establishing safe therapeutic guideline, the effects of PAA on treated crayfish were investigated through assessment of histological changes and oxidative damage. Adult female signal crayfish Pacifastacus leniusculus (n = 135) were exposed to 2 mg L(-1) and 10 mg L(-1) of PAA for 7 days followed by a 7 day recovery period in clean water. Superoxide dismutase activity was significantly lower in gill and hepatopancreas after three days exposure to 10 mg L(1) PAA than in the group treated with 2 mg L(-1) PAA and a control in only clean water. Catalase activity in gill and hepatopancreas remained unaffected by both exposures. Glutathione reductase was significantly decreased in gill of 10 mg L(-1) PAA treated crayfish and increased in group exposed to 2 mg L(-1) compared to control after 7 days exposure. Antioxidant enzyme activity in exposed groups returned to control values after recovery period. Gill, hepatopancreas, and antennal gland showed slight damage in crayfish treated with 2 mg L(-1) of PAA compared to the control group. The extent and frequency of histological alterations were more pronounced in animals exposed to 10 mg L(-1). The gill was the most affected organ, infiltrated by granular hemocytes and displaying malformations of lamella tips and disorganization of epithelial cells. After a 7 day recovery period, the infiltrating cells in affected tissues of the exposed crayfish began to return to normal levels. Results suggested that the given concentrations could be applied to signal crayfish against crayfish plague agent in aquaculture; however, further studies are required for safe use. Copyright © 2015 Elsevier Ltd. All rights reserved.

  10. CONFIRMATION OF OCCURRENCE OF THE NARROW-CLAWED CRAYFISH ? STACUS LEPTODACTYLUS ESCHSCHOLTZ, 1823 IN THE RIVER EVROS IN GREECE

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    PERDIKARIS C.

    2007-04-01

    Full Text Available The narrow-clawed crayfish Astacus leptodactylus Eschscholtz, 1823, is widely distributed in eastern European and western Asian countries. However, species presence in Greece was documented only by limited museum conserved specimens dating back to 1893. Recently (May 2005 several crayfish were captured in the Evros River (close to city of Didimotiho and these were identified as A. leptodactylus. The present work confirms the presence of A. leptodactylus in the Evros River still hundred and twelve years later and introduces the possibility of A. leptodactylus being indigenous to Greece.

  11. Distribution and establishment of the alien Australian redclaw crayfish, Cherax quadricarinatus, in South Africa and Swaziland

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    Ana L. Nunes

    2017-04-01

    Full Text Available Background The Australian redclaw crayfish (Cherax quadricarinatus, von Martens, is native to Australasia, but has been widely translocated around the world due to aquaculture and aquarium trade. Mostly as a result of escape from aquaculture facilities, this species has established extralimital populations in Australia and alien populations in Europe, Asia, Central America and Africa. In South Africa, C. quadricarinatus was first sampled from the wild in 2002 in the Komati River, following its escape from an aquaculture facility in Swaziland, but data on the current status of its populations are not available. Methods To establish a better understanding of its distribution, rate of spread and population status, we surveyed a total of 46 sites in various river systems in South Africa and Swaziland. Surveys were performed between September 2015 and August 2016 and involved visual observations and the use of collapsible crayfish traps. Results Cherax quadricarinatus is now present in the Komati, Lomati, Mbuluzi, Mlawula and Usutu rivers, and it was also detected in several off-channel irrigation impoundments. Where present, it was generally abundant, with populations having multiple size cohorts and containing ovigerous females. In the Komati River, it has spread more than 112 km downstream of the initial introduction point and 33 km upstream of a tributary, resulting in a mean spread rate of 8 km year−1 downstream and 4.7 km year−1 upstream. In Swaziland, estimated downstream spread rate might reach 14.6 km year−1. Individuals were generally larger and heavier closer to the introduction site, which might be linked to juvenile dispersal. Discussion These findings demonstrate that C. quadricarinatus is established in South Africa and Swaziland and that the species has spread, not only within the river where it was first introduced, but also between rivers. Considering the strong impacts that alien crayfish usually have on invaded ecosystems

  12. Electrophysiological Investigation of Different Methods of Anesthesia in Lobster and Crayfish

    Science.gov (United States)

    Fregin, Torsten; Bickmeyer, Ulf

    2016-01-01

    Objectives In search for methods of anesthesia of crustaceans, an implanted electrode into lobster and crayfish CNS enabled us to monitor signal propagation in the nerve system of animals undergoing different protocols. Results Cooling (tap water 0°C, sea water -1,8°C) and anesthesia with MgCl2 (10%) were both discarded as anesthetic procedures because responses to external stimuli were still detectable under treatment. Contrarily, bubbling the aquarium water with CO2 can be considered a “partially successful” anesthesia, because signal propagation is inhibited but before that the animals show discomfort. The procedure of “electro-stunning” induces epileptic-form seizures in the crustacean CNS (lobster, crayfish), which overlay but do not mitigate the response to external stimuli. After several minutes the activity declines before the nervous system starts to recover. A feasible way to sacrifice lobsters is to slowly raise the water temperature (1°C min-1), as all electrical activities in the CNS cease at temperatures above ~30°C, whereas below this temperature the animals do not show signs of stress or escape behavior (e.g. tail flips) in the warming water. Conclusion CO2 is efficient to anaesthetize lobster and crayfish but due to low pH in water is stressful to the animals previous to anesthesia. Electrical stunning induces epileptiform seizures but paralyses the animals and leads to a reversible decline of nerve system activity after seizure. Electric stunning or slowly warming just before preparation may meet ethical expectations regarding anaesthesia and to sacrifice crustaceans. PMID:27642755

  13. ROUNDTABLE SESSION 2B: NATIONAL INTERACTIONS BETWEEN NON-INDIGENOUS AND INDIGENOUS CRAYFISH SPECIES

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    GHERARDI F.

    2002-07-01

    Full Text Available The main object of the present essay is to summarise some aspects underlying the interactions between non-indigenous (NICS and indigenous (ICS crayfish species. The discussion has been also extended to the effects exercised by NICS on the natural habitats they occupy. While doing research on the dyads NICS/ICS, one starting point is to extrapolate common traits that make NICS good invaders from the analysis of their biology, ecology and ethology and the comparison with indigenous species. A subsequent step is to switch attention to the understanding of the characteristics that make ecosystems less vulnerable to invasions and then to analyse both the complex interactions of invaders and target communities and the negative and positive impacts exerted by NICS on the occupied habitats. Examples from Sweden, Britain, and Italy have shown that NICS can replace the native species by a combination of several interacting mechanisms. Besides the transmission of the crayfish plague fungus, mechanisms into action include mostly competitive interference, but also diverse life history traits, recruitment failure, differential susceptibility to predation, and reproductive interference. It has been claimed that invasion theory is full of rules of thumb that, having no precise predictive powers, are thus useless to guide reliable public policy. The solution of the prediction problem requires an in-depth study of every potential invader and target community, trespassing the boundaries among disciplines and having a look at crayfish as a whole and not a single entity. The expectation is thus the return to precise and clear empirical generalisations that can be most useful to develop management strategies.

  14. DISTRIBUTION, RECENT MORTALITIES AND CONSERVATION MEASURES OF CRAYFISH IN HELLENIC FRESH WATERS

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    KOUTRAKIS E.

    2007-04-01

    Full Text Available Freshwater crayfish are found in 20 out of 53 Prefectures of Greece (38% and they form isolated populations in relatively pristine water bodies. Three indigenous crayfish species (ICS occur in Greek waters: Astacus astacus, Astacus leptodactylus and Austropotamobius torrentium, as well as one non-indigenous crayfish species (NICS Pacifastacus leniusculus. Greece represents probably the most southern natural distribution limit for A. astacus and A. torrentium in the world. Concerning NICS, P. leniusculus was imported, at least in two cases, from Sweden and Germany during the early and late 1980’s respectively, in order to replace A. astacus stocks impoverished by human activities. Recently, Cherax quadricarinatus specimens have been seen in a restaurant’s aquarium and pet shop, raising fears about uncontrolled imports of alien pet species. During our 2004-2005 survey, we found that P. leniusculus established not only a thriving population in the artificial Lake Agra (Region of Central Macedonia, but also they co-occur with A. torrentium there. It is also suspected that A. astacus may co-occur there with these two species, as three large male specimens of A. astacus were caught in a creek close to the lake. Concerning A. leptodactylus, there are three sets of preserved samples from the River Evros (state border with Turkey in Thrace today, dated back to the 19th century, but no recent information about occurrence was available. But the accidental catch of six specimens of A. leptodactylus during May 2005 in that river re-documented the occurrence of the species. Finally, a deep-dwelling A. torrentium population with bluish legs was found to live in depths up to 7,800 meters inside the Aggitis Cave in northeastern Greece. There is a lot of work to be done on geographic distribution, population dynamics, genetics, reproduction, nutrition, diseases, and farming of crayfish species in Greece. Moreover, several actions should be undertaken to

  15. The future of the indigenous freshwater crayfish Austropotamobius italicus in Basque Country streams: Is it possible to survive being an inconvenient species?

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    L. García-Arberas

    2009-01-01

    Full Text Available The white-clawed freshwater crayfish Austropotamobius italicus is listed as “vulnerable” in the Spanish Red List of threatened species, but local legislation varies among Spanish regions. Thus, while in some places the species is classified as “in risk of extinction” and various plans of conservation and restoration have been implemented, in the Basque Country and other regions the species is not listed. The distribution of the white-clawed crayfish in the province of Biscay (Basque Country was studied from 1993 to 2007 at more than 600 sampling locations. Results show that 108 streams were inhabited by the native crayfish species A. italicus while 137 streams were inhabited by non-native signal crayfish Pacifastacus leniusculus or red-swamp crayfish Procambarus clarkii. The spread of non-native crayfish is not the only threat to the native species whose survival is also closely dependent on how watersheds are managed. Most A. italicus populations inhabit headwaters, where forestry activities are very important. The presence of native crayfish in heavily forested areas results in a conflict of interests and makes its conservation particularly difficult. We employed a SWOT analysis – an assessment and decision tool commonly used in marketing and business – to evaluate the situation of the native white-clawed crayfish in Biscay, a province characterized by very high demographic pressure. SWOT analysis has proved to be a useful diagnostic tool and can help develop better and more accurate management strategies for the conservation of native crayfish threatened by multiple stressors.

  16. The Use of Fresh Cogongrass as Transportation Media with Level Dry System for Broodstock of Crayfish on Various Old Time

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    Ferdinand Hukama Taqwa

    2015-01-01

    Full Text Available The research was to determine the effect of the use of fresh cogongrass as media packaging filler on survival rate of broodstock of crayfish that transported with level dry system for 24, 48, dan 72 hours which randomized completely design experiment. The research preparation were media preparation of pond water, preparation of filler material and preparation of experimental animal (3 days adaptation after arrived from producer and starvation for 24 hours. The major research were anestetion of broodstock of crayfish with direct sock of low temperature at 12oC for ±5 minutes, transportation experiment of broodstock with fresh cogongrass as material filler. The result showed that the use of fresh cogongrass on various old time of dry level system has a significantly different to time of recovery and survival rate of broodstock of crayfish after tranforted. The fastest time of recovery was 89.55 seconds for 24 hours transportation and significantly different with time of transportation for 48 hours and 72 hours. The survival rate after tranported the highest was 98.89% for 24 hours transportation and significantly different with time of transportation for 48 hours and 72 hours. This research showed that the use of fresh cogongrass as material packaging filler of dry level system was still effective until 48 hours.Keywords: afresh cogongrass, broodstock of crayfish, various old time transportation, level dry system

  17. Antibacterial properties of extracts of Solidago canadensis and their potential use as dietary supplements in red swamp crayfish (Procambarus clarkii

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    Manhong YE,Lei ZHANG,Jiaqi GE,Haifeng SUN,Jingjing NI,Shengmei YANG,Wanhong WEI

    2015-12-01

    Full Text Available Canadian goldenrod (Solidago canadensis is one of the most destructive invasive weeds in South-eastern China. To evaluate its potential application as dietary supplement in red swamp crayfish (Procambarus clarkii, the antibacterial properties of aqueous and ethanol extracts of this plant against three major pathogenic bacteria in crayfish aquaculture were examined. Inhibition zone tests and determination of minimum inhibitory concentration revealed that the extracts had lower antibacterial activity than extracts from two traditional medicinal plants that possess antibacterial properties, garlic (Allium sativum and cortex phellodendri (Phellodendron chinense. However, they did exhibit greater antibacterial effects than extracts from another widely used medicinal plant, Sophora flavescens, and an aquatic weed, Alternanthera philoxeroides. Aqueous extracts of Canadian goldenrod gave greater inhibition than the ethanol extracts. Crayfish fed a diet with 2% these aqueous extracts exhibited significantly higher enzyme activity of alkaline phosphatase, catalase and phenoloxidase (P<0.05. Based on the results of this study, we conclude that aqueous extracts of Canadian goldenrod are highly promising for the development of new dietary supplement for use in crayfish aquaculture.

  18. Mitochondrial DNA provides evidence of a double origin for the stone crayfish Austropotamobius torrentium in the Elbe basin

    Czech Academy of Sciences Publication Activity Database

    Petrusek, A.; Pešek, P.; Leština, Dan; Martin, P.; Fischer, D.; Kozák, P.; Vlach, P.

    2017-01-01

    Roč. 62, JAN 01 (2017), s. 77-83 ISSN 0075-9511 Institutional support: RVO:60077344 Keywords : stone crayfish * Austropotamobius torrentium * Elbe basin Subject RIV: EB - Genetics ; Molecular Biology OBOR OECD: Genetics and heredity (medical genetics to be 3) Impact factor: 1.427, year: 2016 https://www.sciencedirect.com/science/article/pii/S0075951116300901

  19. Accelerated hatching of southern leopard frog (Rana sphenocephala) eggs in response to the presence of a crayfish Procambarus nigrocinctus predator

    Science.gov (United States)

    Daniel Saenz; James B. Johnson; Cory K. Adams; Gage H. Dayton

    2003-01-01

    Phenotypic plasticity, such as morphological and behavioral changes in response to predators, is common in larval anurans. Less is known about inducible defenses in the embryonic stages of development. We investigated the predation risk imposed by crayfish (Procambarus nigrocinctus) on southern leopard frog (Rana sphenocephala)...

  20. MANAGEMENT OF THE WHITE-CLAWED CRAYFISH (AUSTROPOTAMOBIUS PALLIPES IN WESTERN FRANCE: ABIOTIC AND BIOTIC FACTORS STUDY

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    TROUILHE M. C.

    2003-04-01

    Full Text Available In France, the distribution of the white-clawed crayfish, Austropotamobius pallipes (Lereboullet, 1858, is restricted, fragmented and mainly located in headwaters. To preserve this indigenous species, it is necessary to characterize its ecological requirements (water and habitat quality. With this aim in view, a two-year study is being conducted in the Deux-Sèvres department (Western France since November 2002. Nine brooks from four different catchments are monitored regularly; eight of the nine brooks harbour whiteclawed crayfish populations. Two sampling sites are surveyed per brook, the first being where the crayfish population is located and the second 2 to 3 km downstream. Physicochemical parameters (18 are measured twice monthly and biotic factors are estimated twice yearly. In this study, the I.B.G.N. (Indice Biologique Global Normalisé protocol based on the determination of macroinvertebrates was used as a biotic index of biological water quality. Results of this preliminary study on two brooks (Thouet and Verdonnière show that physico-chemical and biological data considered separately do not provide reliable information about A. pallipes ecological requirements. However, the use of multivariate analyses (Principal Component Analysis to combine abiotic and biotic factors highlights a good correlation between these parameters. Organic matter appears to be a better discriminating factor than mineral matter affecting presence or absence of the whiteclawed crayfish.

  1. Investigating the genetic and epigenetic basis of big biological questions with the parthenogenetic marbled crayfish: A review and perspectives.

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    Vogt, Gunter

    2018-03-01

    In the last 15 years, considerable attempts have been undertaken to develop the obligately parthenogenetic marbled crayfish Procambarus virginalis as a new model in biology. Its main advantage is the production of large numbers of offspring that are genetically identical to the mother, making this crustacean particularly suitable for research in epigenetics. Now, a draft genome, transcriptome and genome-wide methylome are available opening new windows for research. In this article, I summarize the biological advantages and genomic and epigenetic features of marbled crayfish and, based on first promising data, discuss what this new model could contribute to answering of ''big'' biological questions. Genome mining is expected to reveal new insights into the genetic specificities of decapod crustaceans, the genetic basis of arthropod reproduction, moulting and immunity, and more general topics such as the genetic underpinning of adaptation to fresh water, omnivory, biomineralization, sexual system change, behavioural variation, clonal genome evolution, and resistance to cancer. Epigenetic investigations with the marbled crayfish can help clarifying the role of epigenetic mechanisms in gene regulation, tissue specification, adult stem cell regulation, cell ageing, organ regeneration and disease susceptibility. Marbled crayfish is further suitable to elucidate the relationship between genetic and epigenetic variation, the transgenerational inheritance of epigenetic signatures and the contribution of epigenetic phenotype variation to the establishment of social hierarchies, environmental adaptation and speciation. These issues can be tackled by experiments with highly standardized laboratory lineages, comparison of differently adapted wild populations and the generation of genetically and epigenetically edited strains.

  2. Hobbseus yalobushensis, a crayfish of intermittent streams: Biotic and habitat associations, life history characteristics, and new localities

    Science.gov (United States)

    Susan B. Adams; Blake A. Davis; Darren A. Miller

    2018-01-01

    Hobbseus yalobushensis, the Yalobusha rivulet crayfish, is a species of conservation concern because it is known from only six localities in parts of three central Mississippi counties. No studies have focused on the species since its description in 1989. Our objectives were to: (1) identify additional H. yalobushensis...

  3. Circadian rhythm in melatonin release as a mechanism to reinforce the temporal organization of the circadian system in crayfish.

    Science.gov (United States)

    Mendoza-Vargas, Leonor; Báez-Saldaña, Armida; Alvarado, Ramón; Fuentes-Pardo, Beatriz; Flores-Soto, Edgar; Solís-Chagoyán, Héctor

    2017-06-01

    Melatonin (MEL) is a conserved molecule with respect to its synthesis pathway and functions. In crayfish, MEL content in eyestalks (Ey) increases at night under the photoperiod, and this indoleamine synchronizes the circadian rhythm of electroretinogram amplitude, which is expressed by retinas and controlled by the cerebroid ganglion (CG). The aim of this study was to determine whether MEL content in eyestalks and CG or circulating MEL in hemolymph (He) follows a circadian rhythm under a free-running condition; in addition, it was tested whether MEL might directly influence the spontaneous electrical activity of the CG. Crayfish were maintained under constant darkness and temperature, a condition suitable for studying the intrinsic properties of circadian systems. MEL was quantified in samples obtained from He, Ey, and CG by means of an enzyme-linked immunosorbent assay, and the effect of exogenous MEL on CG spontaneous activity was evaluated by electrophysiological recording. Variation of MEL content in He, Ey, and CG followed a circadian rhythm that peaked at the same circadian time (CT). In addition, a single dose of MEL injected into the crayfish at different CTs reduced the level of spontaneous electrical activity in the CG. Results suggest that the circadian increase in MEL content directly affects the CG, reducing its spontaneous electrical activity, and that MEL might act as a periodical signal to reinforce the organization of the circadian system in crayfish.

  4. Stone crayfish in the Czech Republic: how does its population density depend on basic chemical and physical properties of water?

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    Vlach P.

    2013-03-01

    Full Text Available The stone crayfish (Austropotamobius torrentium Schrank is one of the two native crayfish species in the Czech Republic. The populations as well as physical and chemical parameters of water (pH, conductivity, dissolved oxygen, undissolved particles, NH3, NH4+, NO2−, NO3−, phosphorus, Ca2+ and SO42 −  of 33 streams were examined to find the ecological plasticity of this crayfish and some relations between these parameters and population densities. The mentioned parameters often significantly varied at the sites. Two approaches were applied to find relations between these parameters and observed abundance. At first, the observed streams were compared using RDA (streams  ×  physical-chemical parameters. No significance was found while testing relationship between the streams grouped along the 1st axis of model and the observed abundances of stone crayfish. However, some correlations between abundance and conductivity, calcium, nitrates and sulphates were found using polynomial regression. These relationships are explicable in terms of mutual correlations, underlying geology and other factors which affect abundances. In conclusion, A. torrentium is able to inhabit waters with a large range of physical and chemical parameters of the water without any fundamental influence on population densities. Water properties play an indisputable role as limiting ecological factors at uncommon concentrations, but population densities are probably influenced much more by the types of habitats, habitat features, predation and other ecological factors.

  5. The first record of translocated white-clawed crayfish from the Austropotamobius pallipes complex in Sardinia (Italy

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    Julien Amouret

    2015-03-01

    Full Text Available The white-clawed crayfish Austropotamobius pallipes complex is native to Europe, being present in 18 European countries, Italy included. However, the number and abundance of its populations are today restricted and it has been recently classified as “endangered” by IUCN (International Union for Conservation of Nature. Here, we report the first record of this freshwater crayfish in Sardinia Island (Italy. Using a fragment of the mitochondrial DNA 16S rRNA gene, we identified three haplotypes that correspond to the A. italicus meridionalis subclade. We provide information about the sampling area, population density and finally discuss hypotheses about the occurrence of this population in Sardinia, comparing it with other Mediterranean populations. Our results improve the existing knowledge about the phylogeography of the taxon across Italy, confirming its complex pattern of distribution. In addition to the non-native status of the Sardinian A. i. meridionalis crayfish, we showed that the most proximal Mediterranean population of white-clawed crayfish existing in Corsica belongs to A. pallipes from Southern France.

  6. Development of crayfish bio-based plastic materials processed by small-scale injection moulding.

    Science.gov (United States)

    Felix, Manuel; Romero, Alberto; Cordobes, Felipe; Guerrero, Antonio

    2015-03-15

    Protein has been investigated as a source for biodegradable polymeric materials. This work evaluates the development of plastic materials based on crayfish and glycerol blends, processed by injection moulding, as a fully biodegradable alternative to conventional polymer-based plastics. The effect of different additives, namely sodium sulfite or bisulfite as reducing agents, urea as denaturing agent and L-cysteine as cross-linking agent, is also analysed. The incorporation of any additive always yields an increase in energy efficiency at the mixing stage, but its effect on the mechanical properties of the bioplastics is not so clear, and even dampened. The additive developing a greater effect is L-cysteine, showing higher Young's modulus values and exhibiting a remnant thermosetting potential. Thus, processing at higher temperature yields a remarkable increase in extensibility. This work illustrates the feasibility of crayfish-based green biodegradable plastics, thereby contributing to the search for potential value-added applications for this by-product. © 2014 Society of Chemical Industry.

  7. Effects of cadmium on the biochemical composition of the freshwater crayfish Procambarus clarkii (Girard, 1852)

    Energy Technology Data Exchange (ETDEWEB)

    Torreblanca, A.; Del Ramo, J.; Diaz-Mayans, J. (Univ. of Valencia (Spain))

    1991-12-01

    Lake Albufera of Valencia (Spain) and the surrounding rice field waters are subjected to very heavy loads of sewage and toxic residues. Among these residues include heavy metals which have been deposited from the many urban and waste waters in this area. The American red crayfish, Procambarus clarkii from Albufera Lake has high resistance to heavy metals. The authors have also found that P. clarkii shows a high capacity for cadmium accumulation in experimental conditions and natural conditions since crayfish collected in this area contained considerable amounts of cadmium in several tissues even after 15 days of depuration in clean water. Since the physiological changes that take place when organisms are exposed to sublethal levels of stress could include rate of feeding as well as respiration and excretion, the net result could be a change in energy available for growth and reproduction. In this work, the authors have studied the biochemical energy composition of hepatopancreas, muscle and gills of P. clarkii after short term sublethal exposure to cadmium.

  8. Neuromodulation of activity-dependent synaptic enhancement at crayfish neuromuscular junction.

    Science.gov (United States)

    Qian, S M; Delaney, K R

    1997-10-17

    Action potential-evoked transmitter release is enhanced for many seconds after moderate-frequency stimulation (e.g. 15 Hz for 30 s) at the excitor motorneuron synapse of the crayfish dactyl opener muscle. Beginning about 1.5 s after a train, activity-dependent synaptic enhancement (ADSE) is dominated by a process termed augmentation (G.D. Bittner, D.A. Baxter, Synaptic plasticity at crayfish neuromuscular junctions: facilitation and augmentation, Synapse 7 (1991) 235-243'[4]; K.L. Magleby, Short-term changes in synaptic efficacy, in: G.M. Edelman, L.E. Gall, C.W. Maxwell (Eds.), Synaptic Function, John Wiley and Sons, New York, 1987, pp. 21-56; K.L. Magleby; J.E. Zengel, Augmentation: a process that acts to increase transmitter release at the frog neuromuscular junction, J. Physiol. (Lond.) 257 (1976) 449-470) which decays approximately exponentially with a time constant of about 10 s at 16 degrees C, reflecting the removal of Ca2+ which accumulates during the train in presynaptic terminals (K.R. Delaney, D.W. Tank, R.S. Zucker, Serotonin-mediated enhancement of transmission at crayfish neuromuscular junction is independent of changes in calcium, J. Neurosci. 11 (1991) 2631-2643). Serotonin (5-HT, 1 microM) increases evoked and spontaneous transmitter release several-fold (D. Dixon, H.L. Atwood, Crayfish motor nerve terminal's response to serotonin examined by intracellular microelectrode, J. Neurobiol. 16 (1985) 409-424; J. Dudel, Modulation of quantal synaptic release by serotonin and forskolin in crayfish motor nerve terminals, in: Modulation of Synaptic Transmission and Plasticity in Nervous Systems, G. Hertting, H.-C. Spatz (Eds.), Springer-Verlag, Berlin, 1988; S. Glusman, E.A. Kravitz. The action of serotonin on excitatory nerve terminals in lobster nerve-muscle preparations, J. Physiol. (Lond.) 325 (1982) 223-241). We found that ADSE persists about 2-3 times longer after moderate-frequency presynaptic stimulation in the presence of 5-HT. This slowing of the

  9. Trapping for invasive crayfish: comparisons of efficacy and selectivity of baited traps versus novel artificial refuge traps

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    Green Nicky

    2018-01-01

    Full Text Available Non-native crayfish can dominate the invertebrate biomass of invaded freshwaters, with their high ecological impacts resulting in their populations being controlled by numerous methods, especially trapping. Although baited funnel traps (BTs are commonly used, they tend to be selective in mainly catching large-bodied males. Here, the efficacy and selectivity of BTs were tested against an alternative trapping method based on artificial refuges (ARTs that comprised of a metal base with several tubes (refuges attached. The target species was signal crayfish Pacifastacus leniusculus in an upland river in southwest England. Trapping was completed in April to October over two consecutive years. In total, 5897 crayfish were captured, with 87% captured in ARTs. Comparison of the catch per unit effort (CPUE between the trapping methods in the same 24 hour periods revealed significantly higher CPUE in ARTs than of BTs. ARTs fished for 6 consecutive days had higher catches than both methods over 24 hours. Whilst catches in BTs were significantly dominated by males (1.49M:1F, the sex ratio of catches in ARTs was 0.99M:1F. The mean carapace length of crayfish was also significantly larger in BTs (43.2 ± 0.6 mm than in ARTs (33.6 ± 0.2 mm. Thus, ARTs had higher CPUE over 24 hour and 6 day periods versus BTs and also captured a greater proportion of smaller and female individuals. These results indicate that when trapping methods are deployed for managing invasions, the use of ARTs removes substantial numbers of crayfish of both sexes and of varying body sizes.

  10. New distributional records of the stygobitic crayfish Cambarus cryptodytes (Decapoda: Cambaridae) in the Floridan Aquifer System of southwestern Georgia

    Science.gov (United States)

    Fenolio, Dante B.; Niemiller, Matthew L.; Gluesenkamp, Andrew G.; Mckee, Anna; Taylor, Steven J.

    2017-01-01

    Cambarus cryptodytes (Dougherty Plain Cave Crayfish) is an obligate inhabitant of groundwater habitats (i.e., a stygobiont) with troglomorphic adaptations in the Floridan aquifer system of southwestern Georgia and adjacent Florida panhandle, particularly in the Dougherty Plain and Marianna Lowlands. Documented occurrences of Dougherty Plain Cave Crayfish are spatially distributed as 2 primary clusters separated by a region where few caves and springs have been documented; however, the paucity of humanly accessible karst features in this intermediate region has inhibited investigation of the species' distribution. To work around this constraint, we employed bottle traps to sample for Dougherty Plain Cave Crayfish and other groundwater fauna in 18 groundwater-monitoring wells that access the Floridan aquifer system in 10 counties in southwestern Georgia. We captured 32 Dougherty Plain Cave Crayfish in 9 wells in 8 counties between September 2014 and August 2015. We detected crayfish at depths ranging from 17.9 m to 40.6 m, and established new county records for Early, Miller, Mitchell, and Seminole counties in Georgia, increasing the number of occurrences in Georgia from 8 to 17 sites. In addition, a new US Geological Survey (USGS) Hydrologic Unit Code 8 (HUC8) watershed record was established for the Spring Creek watershed. These new records fill in the distribution gap between the 2 previously known clusters in Georgia and Jackson County, FL. Furthermore, this study demonstrates that deployment of bottle traps in groundwater-monitoring wells can be an effective approach to presence—absence surveys of stygobionts, especially in areas where surface access to groundwater is limited.

  11. Effects of dietary propolis on the number and size of pleopadal egg, oxidative stress and antioxidant status of freshwater crayfish (Astacus leptodactylus Eschscholtz).

    Science.gov (United States)

    Mişe Yonar, Serpil; Köprücü, Kenan; Yonar, Muhammet Enis; Silici, Sibel

    2017-09-01

    Four different crayfish diets; control, E1, E2 and E3, respectively containing 0, 1, 2 and 4% propolis, were tested to determine the effects of dietary propolis on the number and size of pleopadal egg, and malondialdehyde (MDA) level, superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GSH-Px) activities in the freshwater crayfish (Astacus leptodactylus). The crayfish were kept at 9.6±5.3°C water temperature and fed three times daily during a six month period The pleopodal egg number (from 7 to 9) produced per gram of the body weight and total pleopodal egg number (from 201 to 263) significantly increased (Pegg size (from 3.22mm to 2.76mm). MDA level significantly (Pegg. The dietary propolis improves reproductive efficiency in the crayfish and decreases the oxidative stress under controlled hatchery conditions. Copyright © 2017 Elsevier B.V. All rights reserved.

  12. Isolation of crustecdysone (20R-hydroxyecdysone) from a crayfish (Jasus lalandei H. Milne-Edwards)

    Science.gov (United States)

    Horn, D. H. S.; Fabbri, S.; Hampshire, F.; Lowe, M. E.

    1968-01-01

    1. A small amount (2mg.) of crustecdysone, a moulting hormone of crustaceans, was isolated from 1 ton of crayfish waste. 2. The purification procedure used was developed with the aid of crustacean and insect bioassays. 3. CM-Sephadex was found to be superior to Sephadex and very effective for the chromatographic separation of crustecdysone from other non-ionic compounds. The higher efficiency of CM-Sephadex is attributed to the greater number of carboxyl groups available for hydrogen-bonding. 4. Reversed-phase chromatography, with butan-1-ol–cyclohexane mixtures as the stationary phase and water as the flowing phase, proved superior to countercurrent distribution with these solvents for the fractionation of purified extracts. 5. A second moulting hormone, deoxycrustecdysone, and the red-concentrating hormone were obtained in a partially purified form. PMID:5685865

  13. HERITABILITY AND RESPONSE TO SELECTION FOR GROWTH IN THE F1 GENERATION OF CRAYFISH Procambarus acanthophorus

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    Carlos Perez Rostro

    2012-11-01

    Full Text Available The crayfish Procambarus (A. acanthophorus is a crustacean relevant for regional fisheries in Veracruz, Mexico, with ideal aquaculture characteristics, except for its small size. Thus, a study was conducted with the aim to evaluate the response to selection in the first generation (F1 and heritability (h2 of the crayfish. A group of 2135 organisms with average weight (±S.D. 4.1 ± 1.79 g were captured from the wild (G0, and 10 % (i = 1,755 of the population was selected with the highest body weight by gender: 140 females (5.62 ± 1.97 g and 48 males (6.02 ± 1.9 g, forming the progenitors of the selection line (LS. The control line (LC was formed from a batch obtained at random. Thirty full-sib families were obtained per line (F1, and cultured individually for five months in a recirculation system with mechanical and biological filtration under laboratory conditions and supplied with food twice a day (Camaronina 35 % protein. Monthly heritability (h2 in broad sense was estimated using a full-sib design, based on the components of variance (ANOVA REML method and the growth was compared between lines in the F1. The mean h2's for weight after five months of culture were 0.27±0.11 for LC and 0.34±0.12 for LS, being the LS in F1 9.6 % heavier than the LC, with 84 and 88 % survival at the end of the study. It is possible to implement a breeding program based on selection for species growth.

  14. Interdisciplinarity to reconstruct historical introductions: solving the status of cryptogenic crayfish.

    Science.gov (United States)

    Clavero, Miguel; Nores, Carlos; Kubersky-Piredda, Susanne; Centeno-Cuadros, Alejandro

    2016-11-01

    Anciently introduced species can be confounded with native species because introduction pre-dates the first species inventories or because of the loss of the collective memory of the introductions. The term 'cryptogenic species' denotes species of unknown or unclear status (native versus non-native) in a given territory, and disciplinary approaches are often insufficient for solving their true status. Here, we follow an integrative, multidisciplinary approach to solve the status of a cryptogenic species, proposing that building on evidence from multiple disciplines can produce robust and clarifying insights. We undertook an exhaustive review of information on a putatively native crayfish (Austropotamobius italicus) in Spain. The reviewed information included taxonomy, genetics and phylogeography, history, archaeology, linguistics, biogeography, ecology, symbiotic organisms and even gastronomy and pharmacy. The knowledge produced by different scientific disciplines converges to indicate that A. italicus is a non-native species in Spain. Historical documents even identify the first introduction event: crayfish were shipped from Italy to Spain in 1588 as a diplomatic gift from Francesco I de' Medici to King Philip II of Spain. Previous discussions on the status of A. italicus focussed on inconclusive and often confusing genetic results and excluded the rich and clarifying evidence available from other approaches and disciplines. Interdisciplinarity is an often-invoked but rarely implemented practice in an academic environment that increasingly promotes narrow-focussed specialization. Our review shows that the integration of disciplines can surpass disciplinary approaches in solving scientific controversies. Our results have straightforward implications for strategies to conserve biological diversity in Spain and Europe, urging a debate on the appropriateness of devoting conservation efforts to non-native species. © 2015 Cambridge Philosophical Society.

  15. Astaxanthin from Crayfish (Procambarus clarkii as a Pigmentary Ingredient in the Feed of Laying Hens

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    Garrido-Fernández, J.

    2008-06-01

    Full Text Available Chicken egg yolks generally owe their color to yellow carotenoids. The addition of synthetic red pigments allows changes in color, from the original yellow to red hues which may be more appealing to consumers in certain markets.Our aim has been to test whether ground crayfish shells, which are a rich and natural source of astaxanthin, produce detectable changes in the coloration of egg yolks through the accumulation of this carotenoid. Laying hens were fed with a commercial feed mixed with crayfish powder and the carotenoid profiles of the yolks in the eggs laid during the trial were monitored by HPLC. The analyses showed a progressive increase in the astaxanthin concentration in the egg yolks, reaching similar levels to those obtained for the rest of present carotenoid pigments.La yema de huevo de gallina debe su coloración a la presencia de carotenoides de tonalidad amarilla. La adición de colorantes sintéticos de tonalidades rojas permite modificar e incrementar la coloración de la yema desde el amarillo original a tonos rojos que pueden ser demandados en ciertos mercados según las preferencias del consumidor. El objetivo del trabajo fue probar si un triturado obtenido a partir de caparazones de cangrejo, que es una fuente natural y rica en astaxanteno, produce cambios detectables en la coloración de la yema de huevo por la acumulación de dicho carotenoide. Las gallinas ponedoras se alimentaron con un pienso comercial al que se adicionó triturado de caparazón de cangrejo. Se realizó un seguimiento de los cambios en la composición carotenoide (mediante HPLC de la yema de los huevos puestos durante el periodo de alimentación suplementada. Los análisis mostraron una progresiva incorporación de astaxanteno que alcanzó niveles similares al resto de carotenoides presentes inicialmente en la yema.

  16. CRAYFISH PREDATION ON TADPOLES : A COMPARISON BETWEEN A NATIVE (AUSTROPOTAMOBIUS PALLIPES AND AN ALIEN SPECIES (PROCAMBARUS CLARKII.

    Directory of Open Access Journals (Sweden)

    GHERARDI F.

    2001-04-01

    Full Text Available In the laboratory, the motivation and/or ability to prey on anuran larvae (Bufo bufo, Rana kl. esculenta and R. italica were compared between a native European (Austropotamobius pallipes and an alien North American crayfish species (Procambarus clarkii. Both were skilled predators of tadpoles, adopting a sit-and-wait strategy. However, because P. clarkii displayed lower latency times in the presence of one of the three amphibians (Rana kl. esculenta here tested, the hypothesis is raised that invasive crayfish are more opportunistic predators and possibly faster in switching to different prey than those species they are displacing. From a conservation perspective, these preliminary results further emphasise the importance of studies centred on the invasion-displacement dichotomy.

  17. EVALUATION OF THE AMERICAN WATERWEED (ELODEA CANADENSIS MICHX. AS SUPPLEMENTAL FOOD FOR THE NOBLE CRAYFISH, ASTACUS ASTACUS

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    D’AGARO E.

    2004-01-01

    Full Text Available We conducted a preliminary study to evaluate the capacity of summerling Astacus astacus to consume the American waterweed (Elodea canadensis Michx..under artificial rearing conditions. Summerling A. astacus (initial b.w.: 0.32 ± 0.02 g were cultured (50 crayfish/m2 in 600l tanks for 89 days. The experimental design was composed of three treatments as follows: control diet (D (crude protein: 40.9% DM; ether extract: 7.4% DM, elodea (E (crude protein: 25.8% DM; ether extract: 1.4% DM and control diet + elodea (D + E with three replicates per treatment. Temperature, dissolved oxygen, and other water parameters were measured weekly (T: 20.1°C; O2: 7.2 mg/l; pH: 7.5; N-NH4: 0.05 mg/l; N-NO2: 0.01 mg/l; N-NO3: 29.9 mg/l. The relative growth rate was significantly (P < 0.01 higher in treatment D + E (195% and D (143% than in E (65%. The reduced growth observed in crayfish fed elodea only can probably be due to the lower dietary lipid level of the plant respect to the standard crayfish requirements. At the end of the experiment, the survival rate of A. astacus was higher (P < 0.05 for the treatment D + E (87% and D (81%, compared to E (56%. Our results suggest that E. canadensis can be used as a non-expensive supplemental food in order to increase growth and survival in summerling noble crayfish. They also showed that A. astacus has the potential to consume this macrophyte in nature.

  18. Importance of small fishes and invasive crayfish in otter Lutra lutra diet in an English chalk stream

    OpenAIRE

    Britton, J.R.; Berry, M.; Sewell, S.; Lees, C.; Reading, P.

    2017-01-01

    The diet composition of the European otter Lutra lutra was assessed using spraint analysis in the Hampshire Avon, a lowland chalk stream in Southern England, over an 18-month period. Small cyprinid fishes were the main prey item taken in all seasons, with bullhead Cottus gobio and stone loach Barbatula barbatula also important; there were relatively few larger fishes of interest to fisheries found. There were significant seasonal differences in diet composition by season, with signal crayfish...

  19. CRAYFISH PREDATION EXPERIMENTS ON THE INTRODUCED ZEBRA MUSSEL, DREISSENA POLYMORPHA, IN IRELAND, AND THEIR POTENTIAL FOR BIOCONTROL.

    OpenAIRE

    REYNOLDS J. D.; DONOHOE R.

    2001-01-01

    The zebra mussel Dreissena polymorpha, native to the Aralo-Caspian region, has spread across Europe in the last 180 years. Although it reached England in 1820, it only arrived in Ireland in around 1995, probably attached to the hull of pleasure boats, and since then has spread through the lowland Shannon and Erne systems, which are linked by canal. While White-clawed crayfish Austropotamobius pallipes (Lereboullet) occur in these systems, Dreissena has not yet colonized sites with large crayf...

  20. Stress reaction in crayfish: chlorides help to withstand stress in high nitrite concentration conditions – preliminary study

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    Kozák P.

    2011-06-01

    Full Text Available A non-invasive method of recording cardiac activity (heart rate – HR and stress reaction (stress index – SI was used to understand the immediate and ongoing stress reaction of crayfish to the chemical stimuli. This method detects changes in the shape and amplitude parameters of the response to the stress factors, which characterized the crayfish functional state. Experimental animals (Astacus leptodactylus were divided to the two groups with (400 mg·L-1 Cl− and without added chlorides and then exposed to a stepwise increased level of nitrite to the final (sublethal-lethal concentration of 60 mg·L-1 N-NO\\hbox{$_{2}^{-}$}−2 within 24 hours. The course of crayfish reaction was evident and provided information about their reaction to the sublethal-lethal concentration over time. As expected, a less prominent stress reaction was detected in the group with chlorides. The non-invasive method successfully evaluated the sensing of chemical stimuli in water through HR and SI changes.

  1. The effect of sensory feedback on crayfish posture and locomotion: II. Neuromechanical simulation of closing the loop.

    Science.gov (United States)

    Bacqué-Cazenave, Julien; Chung, Bryce; Cofer, David W; Cattaert, Daniel; Edwards, Donald H

    2015-03-15

    Neuromechanical simulation was used to determine whether proposed thoracic circuit mechanisms for the control of leg elevation and depression in crayfish could account for the responses of an experimental hybrid neuromechanical preparation when the proprioceptive feedback loop was open and closed. The hybrid neuromechanical preparation consisted of a computational model of the fifth crayfish leg driven in real time by the experimentally recorded activity of the levator and depressor (Lev/Dep) nerves of an in vitro preparation of the crayfish thoracic nerve cord. Up and down movements of the model leg evoked by motor nerve activity released and stretched the model coxobasal chordotonal organ (CBCO); variations in the CBCO length were used to drive identical variations in the length of the live CBCO in the in vitro preparation. CBCO afferent responses provided proprioceptive feedback to affect the thoracic motor output. Experiments performed with this hybrid neuromechanical preparation were simulated with a neuromechanical model in which a computational circuit model represented the relevant thoracic circuitry. Model simulations were able to reproduce the hybrid neuromechanical experimental results to show that proposed circuit mechanisms with sensory feedback could account for resistance reflexes displayed in the quiescent state and for reflex reversal and spontaneous Lev/Dep bursting seen in the active state. Copyright © 2015 the American Physiological Society.

  2. EFFECTS OF RATION SIZE AND TEMPERATURE ON MOULT INCREMENT AND METABOLIC PARAMETERS OF JUVENILE NOBLE CRAYFISH, ASTACUS ASTACUS

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    RENAI B.

    2007-07-01

    Full Text Available A laboratory experiment was carried out to test the combined effects of ration size (1 vs 3% body weight, b.w. and temperature (15 ± 2 vs 22 ± 2 °C on moult increment and metabolic parameters of 80 juvenile noble crayfish (Astacus astacus. The maximum daily consumption (Cmax and respiration rate (R were used to calculate the growth scope (i.e. the difference between maximum daily energy consumption and energy costs at a given temperature. The conversion of R into a food-equivalent unit allowed the comparison with Cmax. Results showed that crayfish obtained the maximum moult increment when fed 3% b.w. while temperature seemed to play a less relevant role on growth rate per moult, affecting only the moulting frequency. Crayfish A. astacus fed ad libitum showed a relative insensitivity to the metabolic parameters (oxygen uptake, R and Cmax within the analysed range of temperatures, possibly as a reflection of this “species” distribution across a broad variety of habitats with different thermal regimes. In the present study, A. astacus displayed characteristics proper of a K-selected species, as slow to moderate growth.

  3. Toxicity induced by dieldrin and chlorpyrifos in the freshwater crayfish Cambarellus montezumae (Cambaridae

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    Sandra Díaz-Barriga Arceo

    2015-03-01

    Full Text Available The toxicity induced by insecticides in aquatic organisms is of utmost relevance because it may give a clue about the degree of health or damage of the involved ecosystem. In the present report, we determined the effect of dieldrin (DD and chlorpyrifos (CP on the freshwater crayfish, Cambarellus montezumae. The organisms (4-6cm in diameter were collected in the Ignacio Ramírez Reservoir, situated at 50km Northeast of Mexico City, in the Rio Lerma Basin. Initially, we determined the LC50 value with the Probit method, then the DNA damage with single cell gel electrophoresis (comet assay applied at 24, 48, and 72h of exposure to the brain and hepatopancreas of animals exposed (in reconstituted water to 0.05 and 0.5µg/L of each insecticide. In the hepatopancreas of the same organisms, we determined the lipid peroxidation by applying the TBARS test. DNA damage and lipid peroxidation were also evaluated with the same methods to organisms exposed in water from the reservoir. In regard to the LC50 at 72h of exposure, we found a value of 5.1µg/L and a value of 5.62µg/L for DD and CP, respectively. The comet assay applied at different exposure times showed significant DNA damage to both organs, with respect to the control level. In the case of DD, statistical significance was observed for the two doses in the whole evaluated schedule. CP was genotoxic in the brain with the high dose at 72h, and in the hepatopancreas with the two tested doses at all evaluated exposure times. Also, a significant lipid peroxidation increase was detected with the two doses of insecticides. In the study with water from the reservoir, a more pronounced DNA damage was detected. Our results showed strong DNA damage induced by both insecticides in the crayfish, as well as a correlation with the lipid peroxidation effect, suggesting that oxidative stress is involved in the genotoxic alteration. Our results also showed the usefulness of the studied organism as well as the

  4. Mitotic karyotype of the tropical freshwater crayfish Procambarus (Austrocambarus llamasi (Decapoda: Cambaridae

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    Jeane R Indy

    2010-06-01

    Full Text Available In Mexico, the biology of Procambarus has been more studied than the biology of other Cambarids because of its diversity and potential use in aquaculture. We determined the karyotype of the Mexican tropical freshwater crayfish Procambarus (Austrocambarus llamasi from 189 metaphase spreads from gill tissues of 17 adults. They had 98-120 chromosomes (mode 2n=120 chromosomes. There are 60 pairs of monoarm, telocentric chromosomes. Sex chromosomes were not detected and we propose that the P. llamasi karyotype can be used to distinguish this species from other Mexican crayfish. Additionally, we suggest using karyological data in aquaculture and conservation biology. Rev. Biol. Trop. 58 (2: 655-662. Epub 2010 June 02.El género Procambarus ha recibido mayor atención en los estudios de los principios fundamentales de su biología debido a su diversidad en el territorio mexicano y potencial uso en acuicultura. El cariotipo típico del acocil tropical mexicano Procambarus (Austrocambarus llamasi, se estudió mediante 189 dispersiones cromosómicas en metafase del tejido branquial de 17 adultos tratados con la técnica citológica de inmersión. Encontramos un amplio número de cromosomas, que variaron entre 98-120 elementos cromosómicos, con número modal diploide de 2n=120 elementos cromosómicos. El cariotipo del acocil tropical esta constituido por 60 pares de cromosomas monorrámeos, todos los centrómero están en la región telocéntrica de los cromosomas. En las metafases mitóticas de hembras y machos no fueron identificados cromosomas sexuales. Sugerimos considerar la estructura cromosómica del cariotipo como una herramienta citotaxonómica así como el empleo de datos cariológicos para propósitos de acuicultura y conservación del acocil tropical.

  5. Effects of temperature on the acute toxicity of heavy metals (Cr, Cd, and Hg) to the freshwater crayfish, Procambarus clarkii (Girard)

    Energy Technology Data Exchange (ETDEWEB)

    Del Ramo, J.; Diaz-Mayans, J.; Torreblanca, A.; Nunez, A.

    1987-05-01

    Chromium, an essential trace element for humans and animals is involved in normal carbohydrate metabolism; however, it is toxic at high concentrations. There is no evidence that cadmium and mercury are biologically essential but their toxicity for organisms is well known. Both cause toxic effects at low concentrations to most organisms, especially in combination with other environmental variables such as temperature. Lake Albufera and the surrounding rice field waters are subjected to very heavy loads of sewage and toxic industrial residues (including heavy metals) from the many urban and waste waters in this area. In 1978, the American red crayfish Procambarus clarkii appeared in lake Albufera and in the surrounding rice fields. Without adequate sanitary control, the crayfish is presently being fished commercially for human consumption. The purpose of the present study is to evaluate the degree of toxicity of various heavy metals (chromium, cadmium and mercury) to freshwater crayfish Procambarus clarkii at various temperatures.

  6. Characterization of Population Genetic Structure of red swamp crayfish, Procambarus clarkii, in China.

    Science.gov (United States)

    Yi, Shaokui; Li, Yanhe; Shi, Linlin; Zhang, Long; Li, Qingbin; Chen, Jing

    2018-04-03

    The red swamp crayfish (Procambarus clarkii) is one of the most economically important farmed aquatic species in China. However, it is also a famous invasive species in the world. This invasive species was dispersed most via human activities including intentional or unintentional carry in China. Thus, P. clarkii naturally distributed in China provides us a desirable mode to investigate the genetic structure of an invasive species dispersed mainly by human-mediated factors. To reveal the impact of human-mediated dispersal on genetic structure of P. clarkii in China, a total of 22,043 genome-wide SNPs were obtained from approximately 7.4 billion raw reads using 2b-RAD technique in this study. An evident pattern of population genetic structure and the asymmetrical migrational rates between different regions were observed with 22 populations based on these SNPs. This study provide a better understanding of the population genetic structure and demographic history of P. clarkii populations in China, inferring that anthropogenic factors (aquaculture or by accident) and ecological factors (e.g., complicated topography and climatic environment), as well as its special biological traits could account for the current population structure pattern and dispersal history of P. clarkii.

  7. Nitric oxide-mediated intersegmental modulation of cycle frequency in the crayfish swimmeret system.

    Science.gov (United States)

    Yoshida, Misaki; Nagayama, Toshiki; Newland, Philip

    2018-05-21

    Crayfish swimmerets are paired appendages located on the ventral side of each abdominal segment that show rhythmic beating during forward swimming produced by central pattern generators in most abdominal segments. For animals with multiple body segments and limbs, intersegmental coordination of central pattern generators in each segment is crucial for the production of effective movements. Here we develop a novel pharmacological approach to analyse intersegmental modulation of swimmeret rhythm by selectively elevating nitric oxide levels and reducing them with pharmacological agents, in specific ganglia. Bath application of L-arginine, the substrate NO synthesis, increased the cyclical spike responses of the power-stroke motor neurons. By contrast the NOS inhibitor, L-NAME decreased them. To determine the role of the different local centres in producing and controlling the swimmeret rhythm, these two drugs were applied locally to two separate ganglia following bath application of carbachol. Results revealed that there was both ascending and descending intersegmental modulation of cycle frequency of the swimmeret rhythm in the abdominal ganglia and that synchrony of cyclical activity between segments of segments was maintained. We also found that there were gradients in the strength effectiveness in modulation, that ascending modulation of the swimmeret rhythm was stronger than descending modulation. © 2018. Published by The Company of Biologists Ltd.

  8. Muscle receptor organs in the crayfish abdomen: a student laboratory exercise in proprioception.

    Science.gov (United States)

    Leksrisawat, Bonnie; Cooper, Ann S; Gilberts, Allison B; Cooper, Robin L

    2010-11-18

    The primary purpose of this experiment is to demonstrate primary sensory neurons conveying information of joint movements and positions as proprioceptive information for an animal. An additional objective of this experiment is to learn anatomy of the preparation by staining, dissection and viewing of neurons and sensory structures under a dissecting microscope. This is performed by using basic neurophysiological equipment to record the electrical activity from a joint receptor organ and staining techniques. The muscle receptor organ (MRO) system in the crayfish is analogous to the intrafusal muscle spindle in mammals, which aids in serving as a comparative model that is more readily accessible for electrophysiological recordings. In addition, these are identifiable sensory neurons among preparations. The preparation is viable in a minimal saline for hours which is amenable for student laboratory exercises. The MRO is also susceptible to neuromodulation which encourages intriguing questions in the sites of modulatory action and integration of dynamic signals of movements and static position along with a gain that can be changed in the system.

  9. SIFamide peptides in clawed lobsters and freshwater crayfish (Crustacea, Decapoda, Astacidea): a combined molecular, mass spectrometric and electrophysiological investigation.

    Science.gov (United States)

    Dickinson, Patsy S; Stemmler, Elizabeth A; Cashman, Christopher R; Brennan, Henry R; Dennison, Bobbi; Huber, Kristen E; Peguero, Braulio; Rabacal, Whitney; Goiney, Christopher C; Smith, Christine M; Towle, David W; Christie, Andrew E

    2008-04-01

    Recently, we identified the peptide VYRKPPFNGSIFamide (Val(1)-SIFamide) in the stomatogastric nervous system (STNS) of the American lobster Homarus americanus using matrix-assisted laser desorption/ionization-Fourier transform mass spectrometry (MALDI-FTMS). Given that H. americanus is the only species thus far shown to possess this peptide, and that a second SIFamide isoform, Gly(1)-SIFamide, is broadly conserved in other decapods, including another astacidean, the crayfish Procambarus clarkii, we became interested both in confirming our identification of Val(1)-SIFamide via molecular methods and in determining the extent to which this isoform is conserved within other members of the infraorder Astacidea. Here, we present the identification and characterization of an H. americanus prepro-SIFamide cDNA that encodes the Val(1) isoform. Moreover, we demonstrate via MALDI-FTMS the presence of Val(1)-SIFamide in a second Homarus species, Homarus gammarus. In contrast, only the Gly(1) isoform was detected in the other astacideans investigated, including the lobster Nephrops norvegicus, a member of the same family as Homarus, and the crayfish Cherax quadricarinatus, P. clarkii and Pacifastacus leniusculus, which represent members of each of the extant families of freshwater astacideans. These results suggest that Val(1)-SIFamide may be a genus (Homarus)-specific isoform. Interestingly, both Val(1)- and Gly(1)-SIFamide possess an internal dibasic site, Arg(3)-Lys(4), raising the possibility of the ubiquitously conserved isoform PPFNGSIFamide. However, this octapeptide was not detected via MALDI-FTMS in any of the investigated species, and when applied to the isolated STNS of H. americanus possessed little bioactivity relative to the full-length Val(1) isoform. Thus, it appears that the dodeca-variants Val(1)- and Gly(1)-SIFamide are the sole bioactive isoforms of this peptide family in clawed lobsters and freshwater crayfish.

  10. Biomagnification of some heavy and essential metals in sediments, fishes and crayfish from Ondo State coastal region, Nigeria

    International Nuclear Information System (INIS)

    Asaolu, S.S.; Olaofe, O.

    2005-01-01

    The bio magnifications levels of some essential (Fe, Zn, Cu) and toxic metals (Pb, Ni, Cd, Cr, Co, Mn) were determined in sediments, three kinds of fish (Oreochromis niloticus, Synodonthis sp., and Clarias gariepinus) and crayfish from the Ondo State coastal region. The metal bio magnification in the fish and crayfish was several times greater than in water, while that in the sediments was several thousand-folds greater than in both the organisms and water. Among the metals examined in water, Fe was the most abundant with average values of 146.7 and 74.3 mg/1, respectively, for wet and dry seasons, while Co was the least with average values of 2.4 and 1.6 mg/1. In the sediments, concentrations of Pb, Ni, Fe, Cr, Co and Mn in the wet season were relatively higher than those obtained for the dry season. Fe with an average of 50.9 mg/kg in C, gariepinus was the most abundant metal in the fish samples, while Cu with an average value of 0.3 mg/kg in O. niloticus was the least. The metal bio magnification for most of the metals for both seasons was found to vary widely from one location to the other. This was confirmed by the coefficient of variation that ranged from 31% to 144% and 29% to 130% in the wet and dry seasons, respectively. The present study has shown that fish, crayfish and sediments can be used to monitor the pollution level of metals in the Nigerian coastal water. (author)

  11. Heavy metals bioaccumulation in selected tissues of red swamp crayfish: An easy tool for monitoring environmental contamination levels.

    Science.gov (United States)

    Goretti, E; Pallottini, M; Ricciarini, M I; Selvaggi, R; Cappelletti, D

    2016-07-15

    In this paper we explored the heavy metal bioaccumulation (Cd, Cu, Pb and Zn) in Procambarus clarkii, a crayfish recently suggested as a potential bioindicator for metals pollution in freshwater systems. The present study is focused on crayfishes populations caught in a heavily polluted industrial and in a reference sites (Central Italy), though the results are generalized with a thorough analysis of literature metadata. In agreement with the literature, the hepatopancreas (Hep, detoxification tissues) of the red swamp crayfish showed a higher concentration of heavy metals in comparison to the abdominal muscle (AbM, not detoxification tissues) in the sites under scrutiny. Hep/AbM concentration ratio was dependent on the specific metal investigated and on its sediment contamination level. Specifically we found that Hep/AbM ratio decreases as follows: Cd (11.7)>Cu (5.5)>Pb (3.6)>Zn (1.0) and Pb (4.34)>Cd (3.66)>Zn (1.69)>Cu (0.87) for the industrial and reference sites, respectively. The analysis of our bioaccumulation data as well as of literature metadata allowed to elaborate a specific contamination index (Toxic Contamination Index, TCI), dependent only on the bioaccumulation data of hepatopancreas and abdominal muscle. In the industrial site, TCI expressed values much higher than the unit for Cd and Cu, confirming that these metals were the main contaminants; in contrast for lower levels of heavy metals, as those observed in the reference site for Cu, Zn and Pb, the index provided values below unit. TCI is proposed as a useful and easy tool to assess the toxicity level of contaminated sites by heavy metals in the environmental management. Copyright © 2016. Published by Elsevier B.V.

  12. Recovery of Hafnia alvei from diseased brown trout, Salmo trutta L., and healthy noble crayfish, Astacus astacus (L.), in Bulgaria.

    Science.gov (United States)

    Orozova, P; Sirakov, I; Chikova, V; Popova, R; Al-Harbi, A H; Crumlish, M; Austin, B

    2014-10-01

    Hafnia alvei was isolated in Bulgaria from healthy noble crayfish, Astacus astacus (L.), and then from farmed diseased brown trout, Salmo trutta L., with signs of haemorrhagic septicaemia. The isolates were identified initially with conventional phenotyping and commercial Merlin Micronaut and API 20E rapid identification systems, followed by sequencing of the 16S rRNA gene. Hafnia alvei Bt1, Bt2 and Aa4 were of low virulence to rainbow trout and brown trout, although cytotoxicity was demonstrated by Bt1 and Bt2, but not by Aa4. © 2014 John Wiley & Sons Ltd.

  13. Determination of mercury by cold-vapor technique in several tissues of treated American red crayfish (Procambarus clarkii)

    Energy Technology Data Exchange (ETDEWEB)

    Del Ramo, J.; Pastor, A.; Diaz-Mayans, J.; Medina, J.; Torreblanca, A.

    1988-01-01

    Adult intermolt specimens of American red crayfish (Procambarus clarkii) collected from Lake Albufera (Valencia, Spain), were exposed to mercury during 96 h. The Hg-concentrations used were 50, 100, and 250 ..mu..g Hg/l as Cl/sub 2/Hg. The content of mercury in muscle, midgut gland, antennal glands and gills was investigated. Determinations of mercury were made by cold-vapor technique and AAS. The mercury levels in all examined tissues increased significantly with increasing Hg-concentration in the water.

  14. Yolk proteins during ovary and egg development of mature female freshwater crayfish (Cherax quadricarinatus).

    Science.gov (United States)

    Serrano-Pinto, Vania; Vazquez-Boucard, Celia; Villarreal-Colmenares, Humberto

    2003-01-01

    Vitellins from ovaries and eggs at different stages of development in freshwater crayfish (Cherax quadricarinatus) were examined by chromatography, PAGE and SDS-PAGE. With these methods, two forms of vitellin (Vt1 and Vt2) were observed in ovaries and eggs (stages I and V). In ovaries in secondary vitellogenesis, native molecular mass was 470 (Vt1) and 440 (Vt2) kDa. The electrophoretic pattern of the eggs proved to be more complex. The protein molecular mass depend on the development stage of the egg: stage I, 650 kDa (Vt1) and 440 kDa (Vt2); stage V, 390 kDa (Vt1) and 340 kDa (Vt2). The identified vitellins appear to be lipo-glycocarotenoprotein. A similar vitellin polypeptide composition was observed in the two forms of vitellin from ovaries and eggs in stage V. In ovaries the SDS-PAGE analysis showed four subunits with molecular weights of approximately 180, 120, 95 and 80 kDa (Vt1 and Vt2). The polypeptide composition in the two forms of vitellins in stage I and stage III eggs were different at 195, 190, 130 and 110 kDa (Vt1) and 116 and 107 kDa (Vt2). On the other hand, in stage V eggs, 110, 95, 87 and 75 kDa (Vt1 and Vt2) were identified. Two antibodies (Ab1 and Ab2) were prepared against the purified proteins of stage V eggs and their specificity was demonstrated by radial immunoprecipitation, and Western blotting analysis. Two forms of vitellins were also found in stage V eggs after chromatography on Sepharose CL-2B column and hydroxylapatite and polyacrylamide gel electrophoresis.

  15. The burrows of Parastacus defossus (Decapoda: Parastacidae, a fossorial freshwater crayfish from southern Brazil

    Directory of Open Access Journals (Sweden)

    Clarissa K. Noro

    2010-06-01

    Full Text Available Parastacus defossus Faxon, 1898 is a fossorial crayfish species, which constructs its burrows in swampy areas in southeast Uruguay and in the state of Rio Grande do Sul, Brazil. The present field study was carried out in Lami, Porto Alegre, Rio Grande do Sul, Brazil, from May 2003 through August 2005. Environmental measurements (temperature, pH, dissolved oxygen, and water-table depth of the water in the galleries were made monthly. Burrow morphology was analyzed by means of resin and gypsum casts. The spatial distribution and changes in the number and shape of the surface openings over time were observed in a 100 m² area. To estimate the spatial distribution of the openings, the observed distribution was compared with the expected distribution predicted by the Poisson and Negative Binomial frequency-distribution models. The adult population density was estimated by direct observation of burrows and counts in the study area. Inside the burrows of P. defossus, the water temperature ranged between 16.6°C (autumn 2004 and 23°C (spring 2003. The water was hypoxic and slightly acidic, and the dissolved oxygen content was very low (mean 1.43 mg/l (18.2% saturation. The soil with burrows had higher percentages of coarse sand, fine sand, and silt. The spatial distribution of the openings showed a significant fit to the Negative Binomial distribution, indicating that the distribution of the openings is aggregated, as confirmed from the burrow morphology. The galleries are always formed by a central tunnel with multiple branchings that connect the underground water to the soil surface by one or more openings, which can be recognized by the chimneys. From knowledge of the burrow morphology, the population density was estimated to be about 120 individuals/100 m².

  16. Phylogeny and evolutionary patterns in the Dwarf crayfish subfamily (Decapoda: Cambarellinae.

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    Carlos Pedraza-Lara

    Full Text Available The Dwarf crayfish or Cambarellinae, is a morphologically singular subfamily of decapod crustaceans that contains only one genus, Cambarellus. Its intriguing distribution, along the river basins of the Gulf Coast of United States (Gulf Group and into Central México (Mexican Group, has until now lacked of satisfactory explanation. This study provides a comprehensive sampling of most of the extant species of Cambarellus and sheds light on its evolutionary history, systematics and biogeography. We tested the impact of Gulf Group versus Mexican Group geography on rates of cladogenesis using a maximum likelihood framework, testing different models of birth/extinction of lineages. We propose a comprehensive phylogenetic hypothesis for the subfamily based on mitochondrial and nuclear loci (3,833 bp using Bayesian and Maximum Likelihood methods. The phylogenetic structure found two phylogenetic groups associated to the two main geographic components (Gulf Group and Mexican Group and is partially consistent with the historical structure of river basins. The previous hypothesis, which divided the genus into three subgenera based on genitalia morphology was only partially supported (P = 0.047, resulting in a paraphyletic subgenus Pandicambarus. We found at least two cases in which phylogenetic structure failed to recover monophyly of recognized species while detecting several cases of cryptic diversity, corresponding to lineages not assigned to any described species. Cladogenetic patterns in the entire subfamily are better explained by an allopatric model of speciation. Diversification analyses showed similar cladogenesis patterns between both groups and did not significantly differ from the constant rate models. While cladogenesis in the Gulf Group is coincident in time with changes in the sea levels, in the Mexican Group, cladogenesis is congruent with the formation of the Trans-Mexican Volcanic Belt. Our results show how similar allopatric

  17. Residue analysis of sixty pesticides in red swamp crayfish using QuEChERS with high-performance liquid chromatography-tandem mass spectrometry

    Science.gov (United States)

    In this study, a multi-residue analytical method using QuEChERS extraction and dispersive solid-phase extraction (d-SPE) cleanup followed by high-performance liquid chromatography–tandem mass spectrometry (HPLC-MS/MS) was developed for rapid determination of 60 pesticide residues in whole crayfish a...

  18. Predation of the alien American mink Mustela vison on native crayfish populations in middle-sized streams in central and western Bohemia

    Czech Academy of Sciences Publication Activity Database

    Fischer, D.; Pavluvčík, P.; Sedláček, František; Šálek, Martin

    2009-01-01

    Roč. 58, č. 1 (2009), s. 45-56 ISSN 0139-7893 Institutional research plan: CEZ:AV0Z60870520 Keywords : mink diet * stone crayfish * prey selectivity * density-dependent predation * Czech Republic Subject RIV: EG - Zoology Impact factor: 0.357, year: 2009

  19. Lunar-Rhythmic Molting in Laboratory Populations of the Noble Crayfish Astacus astacus (Crustacea, Astacidea): An Experimental Analysis

    Science.gov (United States)

    Franke, Robert; Hoerstgen-Schwark, Gabriele

    2013-01-01

    Juvenile noble crayfish, Astacusastacus (Crustacea, Astacidea) in the second year of age were kept in the laboratory for a twelve-month period under continuing “summer conditions” (LD 16:8, 19°C). Molting processes in this population could be synchronized by artificial moonlight cycles. Peaks of exuviations occurred at “new moons”. Males showed a slightly higher degree of synchronization than females. A phase-shift of the artificial lunar cycle in relation to the natural cycle resulted in a corresponding shift of the molting cycle. This clearly demonstrates that changes in the nocturnal light regime provide the primary external information for the lunar-monthly molting rhythm. There is a first indication that lunar photic stimuli do not act directly but as a zeitgeber which entrains an endogenous molting rhythm to the lunar cycle. Moreover, the results of the long-term experiments suggest that the hibernal resting period of A . astacus in the field (no molts between October and April) may also involve some endogenous programming. Continuing artificial summer conditions can delay but not completely suppress this resting period. The adaptive significance of the phenomena and how the findings may be applied to improve the management of crowded crayfish stocks are discussed. PMID:23840899

  20. Appropriate Usage Level of Shrimp Waste Meal as Chitin Source for Feeding Young Crayfish (Astacus leptodactylus Esch. 1823

    Directory of Open Access Journals (Sweden)

    Seval Bahadır Koca*, Nalan Ozgur Yigit, Arife Dulluc, Gonca Erol1, Nihal Cılbız1 and Ramazan Kucukkara1

    2011-06-01

    Full Text Available This study was conducted to determine effects of shrimp waste meal as natural chitin source at different rates (0 (control, 10, 20, 30 and 40% on growth, feed conversion ratio (FCR, survival of young crayfish (1.61±0.04 g and 3.74±0.03 cm for 60 days. Fifteen glass aquariums (70x30x40 cm were used in the experiment and 20 individuals were stocked per aquarium (95/m2. The highest of final weight and weight gain were obtained in feed with 10% shrimp waste meal group (3.29±0.23 and 1.66±0.23 g, while the lowest of final weight and weight gain was obtained in fed with 40% shrimp waste meal group (2.75±0.35 and 1.18±0.37 g, respectively. However, non-significant differences were found between final weight, weight gain, specific growth rate, final total length, feed conversion ratio, survival percentage among groups at the end of experimental period. It was concluded that shrimp waste meal as natural chitin source can be used in young crayfish diets up to 40% without adverse effect influence on growth.

  1. Neuromodulation of reciprocal glutamatergic inhibition between antagonistic motoneurons by 5-hydroxytryptamine (5-HT) in crayfish walking system.

    Science.gov (United States)

    Pearlstein, E; Clarac, F; Cattaert, D

    1998-01-23

    In an in vitro preparation of the crayfish thoracic locomotor system, paired intracellular recordings were performed from antagonistic depressor (Dep) and levator (Lev) motoneurons (MNs) that control the second joint of walking legs. Connections between these two groups of MNs consist mainly of inhibitory connections and weak electrotonic synapses. Injection of depolarizing current into a Lev MN results in a hyperpolarization in a Dep MN, and vice versa. This reciprocal glutamatergic inhibition, is not changed in the presence of the sodium channel blocker tetrodotoxin (TTX) and therefore is likely supported by a direct connection between MNs. By contrast, reciprocal inhibition is largely reduced in the presence of 5-hydroxytryptamine (5-HT; 10 microM). Direct micro-application of glutamate pressure-ejected close to an intracellularly recorded MN, evoked an inhibitory response in that MN, accompanied by a decrease of input resistance. These two effects were dramatically reduced in the presence of 5-HT. Thus 5-HT could be involved in mechanisms of dynamic reconfigurations of the neural network controlling leg movements in crayfish.

  2. Novel Insights into Antiviral Gene Regulation of Red Swamp Crayfish, Procambarus clarkii, Infected with White Spot Syndrome Virus

    Directory of Open Access Journals (Sweden)

    Shaokui Yi

    2017-11-01

    Full Text Available White spot syndrome virus (WSSV, one of the major pathogens of Procambarus clarkii, has caused severe disruption to the aquaculture industry of P. clarkii in China. To reveal the gene regulatory mechanisms underlying WSSV infection, a comparative transcriptome analysis was performed among WSSV-infected susceptible individuals (GS, viral resistant individuals (GR, and a non-infected control group (GC. A total of 61,349 unigenes were assembled from nine libraries. Subsequently, 515 and 1033 unigenes exhibited significant differential expression in sensitive and resistant crayfish individuals compared to the control group (GC. Many differentially expressed genes (e.g., C-type lectin 4, Peroxinectin, Prophenoloxidase, and Serine/threonine-protein kinase observed in GR and GS play critical roles in pathogen recognition and viral defense reactions after WSSV infection. Importantly, the glycosaminoglycan biosynthesis-chondroitin sulfate/dermatan sulfate pathway was identified to play critical roles in defense to WSSV infection for resistant crayfish individuals by upregulating the chondroitin sulfate related genes for the synthesis of WSSV-sensitive, functional chondroitin sulfate chains containing E units. Numerous genes and the key pathways identified between resistant and susceptible P. clarkii individuals provide valuable insights regarding antiviral response mechanisms of decapoda species and may help to improve the selective breeding of P. clarkii WSSV-resistance.

  3. Similarity of /sup 241/Am and /sup 59/Fe speciation in selected freshwaters and of their adsorption on crayfish exoskeleton

    Energy Technology Data Exchange (ETDEWEB)

    Vangenechten, J.H.D.; Chughtai, N.A.; Bierkens, J.; Vanderborght, O.L.J.

    1987-01-01

    The particulate fraction and the organically complexed fraction of freshly added /sup 241/Am and /sup 59/Fe were determined in 21 prefiltered surface waters. The adsorptive behaviour of both radionuclides on a biological surface (isolated carapace segments of crayfish) was tested simultaneously. A striking similarity was observed in the chemical and absorptive behaviours of both radionuclides. The stoichiometry of particulate formation revealed a 3/4, Am to Fe ratio. This same stoichiometric relationship was observed in organic complexation, while adsorptive behaviour was characterised by a 1/1, Am to Fe ratio. It is concluded that Am predictably follows the chemistry of freshly added Fe at least over a 15 day period. This observation may find interesting application in risk assessment where use can be made of the well-known geochemical cycling of iron to predict the behaviour of man-made Am.

  4. Similarity of 241Am and 59Fe speciation in selected freshwaters and of their adsorption on crayfish exoskeleton

    International Nuclear Information System (INIS)

    Vangenechten, J.H.D.; Chughtai, N.A.; Bierkens, J.; Vanderborght, O.L.J.

    1987-01-01

    The particulate fraction and the organically complexed fraction of freshly added 241 Am and 59 Fe were determined in 21 prefiltered surface waters. The adsorptive behaviour of both radionuclides on a biological surface (isolated carapace segments of crayfish) was tested simultaneously. A striking similarity was observed in the chemical and absorptive behaviours of both radionuclides. The stoichiometry of particulate formation revealed a 3/4, Am to Fe ratio. This same stoichiometric relationship was observed in organic complexation, while adsorptive behaviour was characterised by a 1/1, Am to Fe ratio. It is concluded that Am predictably follows the chemistry of freshly added Fe at least over a 15 day period. This observation may find interesting application in risk assessment where use can be made of the well-known geochemical cycling of iron to predict the behaviour of man-made Am. (author)

  5. Importance of small fishes and invasive crayfish in otter Lutra lutra diet in an English chalk stream

    Directory of Open Access Journals (Sweden)

    Britton J. Robert

    2017-01-01

    Full Text Available The diet composition of the European otter Lutra lutra was assessed using spraint analysis in the Hampshire Avon, a lowland chalk stream in Southern England, over an 18-month period. Small cyprinid fishes were the main prey item taken in all seasons, with bullhead Cottus gobio and stone loach Barbatula barbatula also important; there were relatively few larger fishes of interest to fisheries found. There were significant seasonal differences in diet composition by season, with signal crayfish Pacifastacus leniusculus only being prominent prey items in warmer months and amphibians in winter, revealing that non-fish resources were seasonally important dietary components. Reconstructed body lengths of prey revealed the only species present in diet >350 mm was pike Esox lucius. These dietary data thus provide important information for informing conservation conflicts between otters and fishery interests.

  6. The effect of sodium ions on the light-induced 86Rb release from the isolated crayfish retina

    International Nuclear Information System (INIS)

    Hartung, K.; Stieve, H.

    1980-01-01

    The effect of low external Na + concentrations on the light-induced K + release from crayfish photoreceptor cells was tested by labelling intracellular K + with the isotope 86 Rb. The amount of isotope released per light, stimulus is roughly proportional to the external Na + concentration if the osmolarity is kept constant by replacing Na + with Tris, choline or sucrose. When sucrose is used to replace the depleted Na + the light-induced K + release is a linear function of the external Na + concentration and is reduced by approx. 95% at an external Na + concentration of 5 mmol/l. For choline and Tris substitutions the relationships are less clear but at Na + concentrations + release is smaller in a Tris solution and larger in a choline solution. It is suggested that the light-induced K + release is due mainly to an activation of voltage sensitive K + channels. (orig.)

  7. What vaccination studies tell us about immunological memory within the innate immune system of cultured shrimp and crayfish.

    Science.gov (United States)

    Chang, Yu-Hsuan; Kumar, Ramya; Ng, Tze Hann; Wang, Han-Ching

    2018-03-01

    The possibility of immunological memory in invertebrates is a topic that has recently attracted a lot of attention. Today, even vertebrates are known to exhibit innate immune responses that show memory-like properties, and since these responses are triggered by cells that are involved in the innate immune system, it seems that immune specificity and immune memory do not necessarily require the presence of B cells and T cells after all. This kind of immune response has been called "immune priming" or "trained immunity". In this report, we review recent observations and our current understanding of immunological memory within the innate immune system in cultured shrimp and crayfish after vaccination with live vaccine, killed vaccine and subunit vaccines. We also discuss the possible mechanisms involved in this immune response. Copyright © 2017 Elsevier Ltd. All rights reserved.

  8. GLUTATHIONE AND ANTIOXIDANT ENZYMES IN THE HEPATOPANCREAS OF CRAYFISH PROCAMBARUS CLARKII (GIRARD, 1852 OF LAKE TRASIMENO (ITALY

    Directory of Open Access Journals (Sweden)

    ELIA A. C.

    2006-01-01

    Full Text Available Antioxidant parameters, such as total glutathione, glutathione S-transferase, glutathione peroxidase, glutathione reductase, glyoxalases, catalase, and some heavy metals such as, lead, cadmium and chromium were examined in hepatopancreas of both sexes of Procambarus clarkii collected seasonally from Lake Trasimeno, from winter 2002-2003 to autumn 2003. Heavy metals content in hepatopancreas in males and females of P. clarkii was low and did not vary through the sampling periods and between sexes. On the contrary, crayfish exhibited sex-dependent differences in levels of some enzyme activities and of total glutathione, and no apparent relationship was found between contaminant burdens and antioxidant indexes in hepatopancreas. Because measured metal concentrations were low, other factors, presumably, were involved in antioxidant variations in P. clarkii and these latter seemed to be affected more by biological and environmental factors, other than those related to pollutants body burdens.

  9. Toxicity of some ricefield pesticides to the crayfish P. clarkii, under laboratory and field conditions in Lake Albufera (Spain).

    Science.gov (United States)

    Andreu-Moliner, E S; Almar, M M; Legarra, I; Núñez, A

    1986-12-01

    Static toxicities in mature crayfish (Procambarus clarkii) were determined, for eight insecticides, two herbicides and one fungicide which were frequently used in rice cultivation at Lake Albufera in Valencia (Spain). Three concentrations of each product were used: a) The concentration that was recommended by the dealer (in mg/L of active ingredient): Carbofuran 0.40, Carbaryl 0.80, Malathion 0.80, Trichlorfon 0.40, Endosulfan 0.56, Lindane 0.56, Fenitrothion 0.40, Cyfloxylate 0.02, Molinate-Thiobencarb 1.50, Copper Sulfate 0.42, b) Half of the recommended concentration. c) Double of the recommended concentration. In all three of the concentrations tested, only Fenitrothion and Cyfloxylate caused a considerable mortality. The other ones do not actually produce any important effects on P. clarkii in our conditions. Nevertheless, insecticides are more toxic than herbicides or fungicides, as the latter show a rather low toxicity.

  10. Two new species of freshwater crayfish of the genus Faxonius (Decapoda: Cambaridae) from the Ozark Highlands of Arkansas and Missouri.

    Science.gov (United States)

    Fetzner, James W Jr; Taylor, Christopher A

    2018-03-22

    Two new species of freshwater crayfish are described from the Ozarks Plateau of northern Arkansas and southern Missouri. Both species are restricted to the mainstem of rocky streams that are at least fourth-order or greater in size. Recent genetic and morphological investigations of the coldwater crayfish, Faxonius eupunctus Williams, 1952, indicated that it was actually composed of several undescribed species. Faxonius eupunctus is herein restricted to just the Eleven Point River system. Faxonius roberti, new species is found in the mainstem of the Spring and Strawberry river systems in northern Arkansas. It differs from F. eupunctus by lacking a male Form-I gonopod with a distal spatulate mesial process, and presence of two spines on the dorsal side of the merus, where F. eupunctus typically has 1 spine. Faxonius wagneri, new species is known from a 54 mile (86 km) stretch of the Eleven Point River mainstem, ranging from just southeast of Greer, Missouri to just north of Birdell, Arkansas. Faxonius wagneri can be differentiated from both F. eupunctus and Faxonius roberti sp. nov. by using the male Form-I and Form-II gonopods, the shape of the chelae, and the female annulus ventralis. In F. wagneri, the terminal elements of the first pleopod are almost twice as long as those in F. eupunctus and F. roberti, with the tips of the appendage reaching the posterior base of the first perieopod when the abdomen is flexed forward, whereas, in the other two species, these elements only reach the base of the second pereiopod. The species also possesses two spines on the dorsal side of the merus of the first pereiopod, which helps distinguish it from F. eupunctus.

  11. Concentrations of elements in fish fillets, fish muscle plugs, and crayfish from the 2011 Missouri Department of Conservation general contaminant monitoring program

    Science.gov (United States)

    May, Thomas W.; Walther, Michael J.; Brumbaugh, William G.; McKee, Michael J.

    2013-01-01

    This report presents the results of a contaminant monitoring survey conducted annually by the Missouri Department of Conservation to examine the levels of selected elemental contaminants in fish fillets, fish muscle plugs, and crayfish. Fillet samples of yellow bullhead (Ameiurus natalis), golden redhorse (Moxostoma erythrurum), longear sunfish (Lepomis megalotis), and channel catfish (Ictalurus punctatus) were collected from six sites as part of the Missouri Department of Conservation’s Fish Contaminant Monitoring Program. Fish dorsal muscle plugs were collected from largemouth bass (Micropterus salmoides) at eight of the sites, and crayfish from two sites. Following preparation and analysis of the samples, highlights of the data were as follows: cadmium and lead residues were most elevated in crayfish tissue samples from the Big River at Cherokee Landing, with 1 to 8 micrograms per gram dry weight and 22 to 45 micrograms per gram dry weight, respectively. Some dorsal muscle plugs from largemouth bass collected from Clearwater Lake, Lake St. Louis, Noblett Lake, Hazel Creek Lake, and Harrison County Lake contained mercury residues (1.7 to 4.7 micrograms per gram dry weight) that exceeded the U.S. Environmental Protection Agency Water Quality Criterion of 1.5 micrograms per gram dry weight of fish tissue (equivalent to 0.30 micrograms per gram wet weight).

  12. Habitat use and population structure of the invasive red swamp crayfish Procambarus clarkii (Girard, 1852 in a protected area in northern Italy

    Directory of Open Access Journals (Sweden)

    Donato Roberta

    2018-01-01

    Full Text Available The red swamp crayfish Procambarus clarkii is one of the most invasive alien species in Europe and included in the list of invasive species of Union concern. We describe for the first time some life-history traits of a red swamp crayfish population in the Nature Reserve of the Lago di Candia (Italy. We investigated (1 preferences of this species for specific environmental features on the banks of the lake, and (2 differences in size, sex ratio, and condition index between individuals caught in lake and marsh. Moreover, we compared sampling effort and the features of individuals caught in the lake, for two sampling seasons in 2014 and 2015. Findings indicated that the population was well established, and the marsh seemed to have better conditions for growth of individuals than the lake. Accordingly, continuity of riparian vegetation, opportunity to dig burrows, and trophic resource availability seems to facilitate the proliferation of the crayfish in the lake. Our study demonstrated that massive removal efforts over the whole active period of the species and more than one year of trapping are necessary to increase the controlling activities' success. This study could have important implications for further population management projects directed at biodiversity conservation in the area.

  13. Relative distribution and abundance of fishes and crayfish in 2010 and 2014 prior to saltcedar (Tamarix ssp.) removal in the Amargosa River Canyon, southeastern California

    Science.gov (United States)

    Hereford, Mark E.

    2016-07-22

    The Amargosa River Canyon, located in the Mojave Desert of southeastern California, contains the longest perennial reach of the Amargosa River. Because of its diverse flora and fauna, it has been designated as an Area of Critical Environmental Concern and a Wild and Scenic River by the Bureau of Land Management. A survey of fishes conducted in summer 2010 indicated that endemic Amargosa River pupfish (Cyprinodon nevadensis amargosae) and speckled dace (Rhinichthys osculus spp.) were abundant and occurred throughout the Amargosa River Canyon. The 2010 survey reported non-native red swamp crayfish (Procambarus clarkii) and western mosquitofish (Gambusia affinis) captures were significantly higher, whereas pupfish captures were lower, in areas dominated by non-native saltcedar (Tamarix ssp.). Based on the 2010 survey, it was hypothesized that the invasion of saltcedar could result in a decrease in native species. In an effort to maintain and enhance native fish populations, the Bureau of Land Management removed saltcedar from a 1,550 meter reach of stream on the Amargosa River in autumn 2014 and autumn 2015. Prior to the removal of saltcedar, a survey of fishes and crayfish using baited minnow traps was conducted in the treatment reach to serve as a baseline for future comparisons with post-saltcedar removal surveys. During the 2014 survey, 1,073 pupfish and 960 speckled dace were captured within the treatment reach. Catch per unit effort of pupfish and speckled dace in the treatment reach was less in 2014 than in 2010, although differences could be owing to seasonal variation in capture probability. Non-native mosquitofish catch per unit effort decreased from 2010 to 2014; however, the catch per unit effort of crayfish increased from 2010 to 2014. Future monitoring efforts of this reach should be conducted at the same time period to account for potential seasonal fluctuations of abundance and distribution of fishes and crayfish. A more robust study design that

  14. The assessment of the habitat and water quality requirements of the stone crayfish (Austropotamobius torrentium and noble crayfish (Astacus astacus species in the rivers from the Anina Mountains (SW Romania

    Directory of Open Access Journals (Sweden)

    Pârvulescu L.

    2011-02-01

    Full Text Available The species Austropotamobius torrentium and Astacus astacus are two species known in the EU directives to require deeper understanding of their autecologic requirements before any sustainable conservation effort could be successfully applied. Therefore, the paper aims to analyze the occurrence of these two species of crayfish in the Anina Mountains (Romania in relation to several physical-chemical indicators measured on site. The results suggest that the anthropogenic impacts registered in some of the sampling sites (e.g. organic pollution and river bed modification might have triggered the disappearance of both species from the areas of the water sheds situated downstream villages and towns, deforestation sites and sewage treatment plants. The analysis suggest that both species might have similar ecologic requirements, with a BMWP score of 8 (out of a possible 10, therefore good indicators of pristine aquatic environments and with a possible toleration to pollution but only up to a moderate level. Nevertheless, the lack of cohabitation of the populations of both species at a local scale was discussed along with two possible explaining hypotheses: behavioral exclusion or different times and/or modalities of dispersal history.

  15. Fatty acids and astaxanthin composition of two edible native Mexican crayfish Cambarellus (C.) montezumae and Procambarus (M.) bouvieri

    International Nuclear Information System (INIS)

    Coral-Hinostroza, G.; Diaz-Martinez, M.; Huberman, A.; Silencio-Barrita, J.L.

    2016-01-01

    The content and composition of the fatty acids (F As) and astaxanthin (AST) in the edible forms of crayfish: the whole animal of Cambarellus (C.) montezumae, and the tail meat (TM) of Procambarus (M.) bouvieri were determined by GC and HPLC. The exoskeleton (EXK) of P. (M.) bouvieri was also studied. Unsaturated FAs, and mostly oleic acid (C18:1 n-9), were predominant in both edible forms. The contents of the polyunsaturated eicosapentaenoic (C20:5 n-3, EPA), arachidonic (C20:4 n-6, ARA) and docosahexaenoic acid (C22:6 n-3, DHA), were higher in the TM of P. (M.) bouvieri than in the complete C. (C.) montezumae (p 79.50%). AST esters were enriched with saturated FAs in C. (C.) montezumae and with PUFAs in EXK of P. (M.) bouvieri. We conclude that both C. (C.) montezumae and the TM of P. (M.) bouvieri are traditional foods rich in n-3 PUFAs and C. (C.) montezumae in AST. The EXK of P. (M.) bouvieri is a rich potential source of AST, n-3 PUFAs, and the combination AST-DHA. [es

  16. Inferring Invasion History of Red Swamp Crayfish (Procambarus clarkii) in China from Mitochondrial Control Region and Nuclear Intron Sequences

    Science.gov (United States)

    Li, Yanhe; Guo, Xianwu; Chen, Liping; Bai, Xiaohui; Wei, Xinlan; Zhou, Xiaoyun; Huang, Songqian; Wang, Weimin

    2015-01-01

    Identifying the dispersal pathways of an invasive species is useful for adopting the appropriate strategies to prevent and control its spread. However, these processes are exceedingly complex. So, it is necessary to apply new technology and collect representative samples for analysis. This study used Approximate Bayesian Computation (ABC) in combination with traditional genetic tools to examine extensive sample data and historical records to infer the invasion history of the red swamp crayfish, Procambarus clarkii, in China. The sequences of the mitochondrial control region and the proPOx intron in the nuclear genome of samples from 37 sites (35 in China and one each in Japan and the USA) were analyzed. The results of combined scenarios testing and historical records revealed a much more complex invasion history in China than previously believed. P. clarkii was most likely originally introduced into China from Japan from an unsampled source, and the species then expanded its range primarily into the middle and lower reaches and, to a lesser extent, into the upper reaches of the Changjiang River in China. No transfer was observed from the upper reaches to the middle and lower reaches of the Changjiang River. Human-mediated jump dispersal was an important dispersal pathway for P. clarkii. The results provide a better understanding of the evolutionary scenarios involved in the rapid invasion of P. clarkii in China. PMID:26132567

  17. Inferring Invasion History of Red Swamp Crayfish (Procambarus clarkii in China from Mitochondrial Control Region and Nuclear Intron Sequences

    Directory of Open Access Journals (Sweden)

    Yanhe Li

    2015-06-01

    Full Text Available Identifying the dispersal pathways of an invasive species is useful for adopting the appropriate strategies to prevent and control its spread. However, these processes are exceedingly complex. So, it is necessary to apply new technology and collect representative samples for analysis. This study used Approximate Bayesian Computation (ABC in combination with traditional genetic tools to examine extensive sample data and historical records to infer the invasion history of the red swamp crayfish, Procambarus clarkii, in China. The sequences of the mitochondrial control region and the proPOx intron in the nuclear genome of samples from 37 sites (35 in China and one each in Japan and the USA were analyzed. The results of combined scenarios testing and historical records revealed a much more complex invasion history in China than previously believed. P. clarkii was most likely originally introduced into China from Japan from an unsampled source, and the species then expanded its range primarily into the middle and lower reaches and, to a lesser extent, into the upper reaches of the Changjiang River in China. No transfer was observed from the upper reaches to the middle and lower reaches of the Changjiang River. Human-mediated jump dispersal was an important dispersal pathway for P. clarkii. The results provide a better understanding of the evolutionary scenarios involved in the rapid invasion of P. clarkii in China.

  18. Effects of different protein and carbohydrate contents on growth and survival of juveniles of southern Chilean freshwater crayfish, Samastacus spinifrons

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    Italo Salgado-Leu

    2015-11-01

    Full Text Available In cultivated aquatic organisms nutritional requirements are critical, not only for their impact on production techniques, but also, for their high incidence on production costs. There is limited knowledge on some species such as the southern Chilean freshwater crayfish, Samastacus spinifrons. In order to generate practical knowledge, a study was carried out to determine protein and carbohydrate content requirements. These factors were evaluated upon their effects on growth and survival of juveniles. For this purpose, individual weight, biomass gain, survival, and feed conversion parameters were measured. The assay was carried out in 42 days, it was conducted in a flow through system, using 21 plastic tanks of 10.6 L capacity. Each tank was seeded with 20 juveniles weighing 50 mg average each. A 3×2 factorial design was proposed with three protein contents (20, 30, 40% and two carbohydrate contents (low: from 16.3 to 23.5% and high: from 34.6 to 35.8%. Six treatments and three replicates were performed. Individuals were fed on apparent satiation once a day. The diets formulated with 30% of protein and the two carbohydrate contents resulted in higher biomass increases, food conversion efficiencies over 26%, and specific growth rate of 0.78%, all displaying significant differences. Survival showed highly significant differences; in all diets were superior to 60%, however the diets with 30% of protein surpassed 90%.

  19. BIOLOGICAL WATER QUALITY ASSESSMENT OF THE WHITECLAWED CRAYFISH HABITAT BASED ON MACROINVERTEBRATE COMMUNITIES: USEFULNESS FOR ITS CONSERVATION

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    GRANDJEAN F.

    2003-04-01

    Full Text Available A survey of the macroinvertebrates of three brooks harbouring the white-clawed crayfish was conducted in Haute-Vienne department (France. Its aim was to increase our understanding of these ecosystems to help the conservation of A. pallipes. These brooks run through pastoral areas with well-developed riparian vegetation, which offers an important shade. Water temperature, dissolved oxygen concentration, pH, and conductivity fell within the ranges found for this species. A total of 34, 31, 29 taxa and 1 502, 1 364, 2 707 individuals of macrobenthos were collected in Holme, Besque and Bellecombe streams, respectively. Results showed good to very good water quality with IBGN scores ranging from 15 (Bellecombe to 17 (Holme and Besque, reflecting a limited impact of the anthropogenic disturbances. Taxa diversity were high for Holme and Besque with Shannon index around 3.2, translating a great heterogeneity of habitat and an equilibrated faunal community. Bellecombe showed a limited diversity with Shannon index of 1.42, resulting from the presence of numberous Chironomidae. This brook suffers probably weak organic pollution which could be related to the low water flow observed during the sampling. The similarity test according to Jaccard index showed high percentage of common taxa among ETP (Ephemeroptera-Trichoptera-Plecoptera between all sites. The high similarity of benthic macroinvertebrate communities could be an useful criteria to identify brooks for restocking purpose.

  20. Clinical features of Haff disease and myositis after the consumption of boiled brackish water crayfish: a retrospective study of 96 cases at a single centre.

    Science.gov (United States)

    He, Fei; Ni, Jun; Huang, Jun-Ai; Liu, Yao; Wu, Chao; Wang, Jun

    2018-05-08

    The present study describes the difference in clinical features between the patients with Haff disease and crayfish-related myositis (CRM) after crayfish consumption. This was a single-centre, retrospective analysis at the Emergency Department of the Drum Tower Hospital of Nanjing University School of Medicine from July to August of 2016. The baseline information came from the Electronic Medical Record System at the institution. Totally 96 patients were included, of whom 52 patients were confirmed to have Haff disease and 44 patients were CRM. The illness predominately occurs in summer and most of them (55/96) are female. The primary clinical features are myalgia, muscle allodynia and back and body pain. Statistical differences in the baseline CK, CK-MB, myoglobin, and the WBC count exist between the Haff disease and CRM groups (P < 0.05). The serum levels of CK and CK-MB increase in the second (a median time 29.2 ± 7.4 h) or third day (a median time 54.8 ± 9.3 h) of disease course, and then rapidly decreased to normal levels, while the levels of myoglobin peak at the admission (a median time 7.7 ± 6.4 h) and became normal after admission. There were no fatalities or complications during this study. All 96 patients recovered in a week. Of them, 75 were followed-up within 1 month and none had recurrence. The Haff disease and CRM after boiled crayfish consumption reflect a different severity of muscle injury, and reveal similar clinical characteristics and most of the laboratory values. The overall prognosis of both is good.

  1. Proteomic analysis of the crayfish gastrolith chitinous extracellular matrix reveals putative protein complexes and a central role for GAP 65.

    Science.gov (United States)

    Glazer, Lilah; Roth, Ziv; Weil, Simy; Aflalo, Eliahu D; Khalaila, Isam; Sagi, Amir

    2015-10-14

    Chitin is a major component of arthropod cuticles, where it forms a three-dimensional network that constitutes the scaffold upon which cuticles form. The chitin fibers that form this network are closely associated with specific structural proteins, while the cuticular matrix contains many additional structural, enzymatic and other proteins. We study the crayfish gastrolith as a simple model for the assembly of calcified cuticular structures, with particular focus on the proteins involved in this process. The present study integrates a gastrolith-forming epithelium transcriptomic library with data from mass spectrometry analysis of proteins extracted from the gastrolith matrix to obtain a near-complete picture of gastrolith protein content. Using native protein separation we identified 24 matrix proteins, of which 14 are novel. Further analysis led to discovery of three putative protein complexes, all containing GAP 65 the most abundant gastrolith structural protein. Using immunological methods we further studied the role of GAP 65 in the gastrolith matrix and forming epithelium, as well as in the newly identified protein complexes. We propose that gastrolith matrix construction is a sequential process in which protein complexes are dynamically assembled and disassembled around GAP 65, thus changing their functional properties to perform each step in the construction process. The scientific interest on which this study is based arises from three main features of gastroliths: (1) Gastroliths possess partial analogy to cuticles both in structural and molecular properties, and may be regarded, with the appropriate reservations (see Introduction), as simple models for cuticle assembly. At the same time, gastroliths are terminally assembled during a well-defined period, which can be controlled in the laboratory, making them significantly easier to study than cuticles. (2) Gastroliths, like the crayfish exoskeleton, contain stable amorphous calcium carbonate (ACC) rather

  2. Behavioral and electrophysiological evidence for the mechanisms involved in the detection of ionizing radiations by the crayfish Pacifastacus trowbridgii

    International Nuclear Information System (INIS)

    Rodriguez, A.

    1976-01-01

    The light-adapted crayfish, Pacifastacus trowbridgii, displayed a behavioral response to exposure to 300 kV x-rays at exposure rates of 10 to 30 R/s. Within this range, the proportion of subjects that responded increased with an increase in exposure rate. The response latency was inversely proportional to the exposure rate. Ophthalmectomized animals exhibited a similar response with a significantly shorter latency than the intact animals at the same exposure rate (30 R/s). Partial body exposure of ophthalmectomized animals also elicited a behavioral response and indicated that a radiation-sensitive receptor was located in the abdomen. X-ray exposure of the dark-adapted compound eye evoked an electroretinogram (ERG) that was similar to the light evoked ERG. The x-ray evoked ERG amplitude was found to be dependent on total exposure for stimulus durations of 300 ms or less. With stimulus durations greater than 300 ms, the ERG amplitude increased in relation to the logarithm of the exposure rate. Similar responses with light indicated that the mechanism of interaction may be the same for x-rays. The time course for maximal dark-adaptation, after a 500 ms exposure to 3.85 ft-c of light, was comparable for both x-ray and light exposure (9 min). Differences observed in ERG amplitude between the light and x-ray evoked responses during the initial recovery period can be attributed to absorption of light by migrating accessory pigments or by differential interaction of light with photosensitive pigments in the eye

  3. Feasibility, density and growth of culture of freshwater crayfish (Decapoda: Cherax Quadricarinatus in Sinaloa, México

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    Juan Francisco Arzola González

    2012-09-01

    Full Text Available Feasibility, density and growth of culture of freshwater crayfish (Cherax quadricarinatus in Sinaloa were analyzed between September, 2005 and January, 2006. The densities were 7 (reservoir 1 and 16 (reservoir 2 org/m-2. Applied a method not parametrico (Kruskal-Wallis, the variables of response were density, weight and sex, the experimental unit the reservoirs. Samplings were weekly and 40 lobsters were captured in tubes of PVC. Total and cefalotorácica length ((LT y LC in mm and total weight (PT in g of the organisms were recorded, the biometric correlations were realized and von Bertalanffy estimated the growth for the model of von Bertallanfy. The major average was obtained in 41.2 g to a density of 7 org/m, though her k (growth rate coincided with the reservoirs with 0.30, in addition, the lobsters they presented a growth of isometric type. From the first year, usefulness of $3,419,165.00 obtained, that represented 26.8 % of the total of income, keeping a growth like that supported until the fifth year (2011. The financial evaluation determined that the investment is profitable economically, his analysis of VAN was $9,060,554.00, and in agreement to the financial indicators, this value was ideal for the accomplishment of the project. As indicator of the profitability, the TIR resulted in 66 %, being major that the minimal acceptable rate of performance and concluding the profitability of the culture in 59 %. Likewise, Sinaloa's condition, for his geographical location and the results ofthe growth, the heights, the performance of the lobster and of the financial analysis of the culture, indicated to C. quadricarinatusas an alternative of development in the region, being the lobster of interest in acuiculture of new species in tropical areas, thoughin Sinaloa the investigations are practically void with ends of commercial production.

  4. Effects of both ecdysone and the acclimation to low temperature, on growth and metabolic rate of juvenile freshwater crayfish Cherax quadricarinatus (Decapoda, Parastacidae

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    Anouk Chaulet

    2013-06-01

    Full Text Available Growth, metabolic rate, and energy reserves of Cherax quadricarinatus (von Martens, 1868 juveniles were evaluated in crayfish acclimated for 16 weeks to either 25ºC (temperature near optimum or 20ºC (marginal for the species. Additionally, the modulating effect of ecdsyone on acclimation was studied. After 12 weeks of exposure, weight gain of both experimental groups acclimated to 25ºC (control: C25, and ecdysone treated: E25 was significantly higher than that of those groups acclimated to 20ºC (C20 and E20. A total compensation in metabolic rate was seen after acclimation from 25ºC to 20ºC; for both the control group and the group treated with ecdysone. A Q10value significantly higher was only observed in the group acclimated to 20ºC and treated with ecdysone. A reduction of glycogen reserves in both hepatopancreas and muscle, as well as a lower protein content in muscle, was seen in both groups acclimated to 20ºC. Correspondingly, glycemia was always higher in these groups. Increased lipid levels were seen in the hepatopancreas of animals acclimated to 20ºC, while a higher lipid level was also observed in muscle at 20ºC, but only in ecdysone-treated crayfish.

  5. Tracking the invasion of the red swamp crayfish Procambarus clarkii (Girard, 1852 (Decapoda Cambaridae in Sicily: a “citizen science” approach

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    Francesco Paolo Faraone

    2017-11-01

    Full Text Available The first record of the red swamp crayfish in Sicily dates back to 2003 and, since then, the species seemed to be confined to a few localities in western Sicily. A small “citizen science” project carried out from November 2016 onwards led to the creation of the “Sicilian Procambarus working group” (SPwg, which aims at monitoring the distribution and impact of the species in Sicily. To date, the SPwg found the red swamp crayfish in five new sites on the island, thus doubling the number of local sites of occurrence. The new Procambarus clarkii sites lie in different river basins, some of them located several hundred kilometres from the invaded areas known to date, suggesting the existence of multiple independent releases of the species in the wild. The need of better informing the local population on the risks exerted by invasive species on biological diversity, and of carefully monitoring the impact of P. clarkii on the Sicilian inland water biota is briefly stressed.

  6. From Blood to Brain: Adult-Born Neurons in the Crayfish Brain Are the Progeny of Cells Generated by the Immune System

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    Barbara S. Beltz

    2017-12-01

    Full Text Available New neurons continue to be born and integrated into the brains of adult decapod crustaceans. Evidence in crayfish indicates that the 1st-generation neural precursors that generate these adult-born neurons originate in the immune system and travel to the neurogenic niche via the circulatory system. These precursors are attracted to the niche, become integrated amongst niche cells, and undergo mitosis within a few days; both daughters of this division migrate away from the niche toward the brain clusters where they will divide again and differentiate into neurons. In the crustacean brain, the rate of neuronal production is highly sensitive to serotonin (5-hydroxytryptamine, 5-HT levels. These effects are lineage-dependent, as serotonin's influence is limited to late 2nd-generation neural precursors and their progeny. Experiments indicate that serotonin regulates adult neurogenesis in the crustacean brain by multiple mechanisms: via direct effects of serotonin released from brain neurons into the hemolymph or by local release onto target cells, or by indirect influences via a serotonin-mediated release of agents from other regions, such as hormones from the sinus gland and cytokines from hematopoietic tissues. Evidence in crayfish also indicates that serotonin mediates the attraction of neural precursors generated by the immune system to the neurogenic niche. Thus, studies in the crustacean brain have revealed multiple roles for this monoamine in adult neurogenesis, and identified several pathways by which serotonin influences the generation of new neurons.

  7. RECENT SUSPECT CASES AND A PILOT DETECTION STUDY

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    KOZUBÍKOVÁ E.

    2006-01-01

    Full Text Available There are only very limited reports about the occurrence of the crayfish plague in Czechia. In recent years, mass mortalities of Astacus spp. with symptoms of possible crayfish plague were noticed in three streams in the country – two in Central Bohemia (1998-9 and one in Silesia (2004. Three dead individuals from the last outbreak were examined for the presence of the crayfish plague pathogen, Aphanomyces astaci, by observation of the presence of hyphae in their cuticle and by a PCR-based diagnostic method. In all three cases the detection was positive. Although causes of mass mortalities from two other localities lack such a direct confirmation, the indirect evidence supports the same conclusion. The main potential vector of A. astaci in Czechia is the American spiny-cheeck crayfish Orconectes limosus, widespread in large rivers of the western part of the country and in various isolated standing waters. Using the same molecular method, we investigated the presence of A. astaci in living O. limosus individuals from six localities (three running and three standing waters. The analysis indicated the presence of the pathogen in animals from five out of six investigated Orconectes populations. One of them is present in the stream where two European Astacus species had gone extinct in 1998-9. Our results suggest that the crayfish plague is still present in Czechia, and that populations of O. limosus represent a reservoir for the crayfish plague pathogen, which directly endangers populations of the native crayfish.

  8. Food preference and feeding rhythm in red swamp crayfish Procambarus clarkii%克氏原螯虾的食物选择性及其摄食节律

    Institute of Scientific and Technical Information of China (English)

    徐增洪; 周鑫; 水燕

    2012-01-01

    Juvenile and adult red swamp crayfish (Procambarus clarkii) were reared in tanks (60 cm × 40 cm × 40 cm) at a rate of 20 individuals per tank and fed 5 aquatic plant species (Altemanthera philoxeroides, Eichhornia crassipes, Lesser duckweed Lemna minor, Elodea nultallii, and pondweed ValUsneria natans) to evaluate food I-tems and changes in food filling in stomach and intestines during day and night. In addition, the growth was compared in th crayfish reared in a paddyfield and fed three diets ( crayfish feedstuff with 30% protein, aquatic grasses and trash fish). The food in the intestine of the juvenile crayfish was found to be primarily comprised of zooplankton and phytoplankton. The adult crayfish was shown to have lower food preference, almost all of edible aquatic animals and plants, organic detritus, and artificial feed available in waters being consumed, and aquatic plants constituting their main food due to wide distribution, and easy ingesting. The feeding rhythm was observed during day and night in the crayfish culture pond, the two peaks at 8:00-10:00 and 19:00-22:00. There was significantly better growth in the adult crayfish fed Elodea nuttallii, Lesser duckweed and Vallisneria natans than that in the crayfish fed Altemanthera philoxeroides and Eichharnia crassipes(P0. 05) , even though the crayfish fed Lesser duckweed had slightly better growth than the crayfish fed Elodea nuUallii, and ValUsneria natans did. There was significant difference in daily weight gain rate in the juvenile crayfish fed lesser duckweed, Elodea nuttallii, Vallisneria natans, Altemanthera philoxeroides,Eichhornia crassipes(P<0.05). In the rice field, however, the crayfish fed trash fish was shown to have much better growth than that the crayfish fed pelleted food, and pelleted feedstuff combined with aquatic plants.%对克氏原螫虾Procambarus clarkii幼虾和成虾的胃及肠道内的食物组成和食物充塞度的昼夜变化规律进行了观察;在水族箱(60 cm

  9. Modification of sodium and potassium channel kinetics by diethyl ether and studies on sodium channel inactivation in the crayfish giant axon membrane

    Energy Technology Data Exchange (ETDEWEB)

    Bean, Bruce Palmer [Univ. of Rochester, NY (United States)

    1979-01-01

    The effects of ether and halothane on membrane currents in the voltage clamped crayfish giant axon membrane were investigated. Concentrations of ether up to 300 mM and of halothane up to 32 mM had no effect on resting potential or leakage conductance. Ether and halothane reduced the size of sodium currents without changing the voltage dependence of the peak currents or their reversal potential. Ether and halothane also produced a reversible, dose-dependent speeding of sodium current decay at all membrane potentials. Ether reduced the time constants for inactivation, and also shifted the midpoint of the steady-state inactivation curve in the hyperpolarizing direction. Potassium currents were smaller with ether present, with no change in the voltage dependence of steady-state currents. The activation of potassium channels was faster with ether present. There was no apparent change in the capacitance of the crayfish giant axon membrane with ether concentrations of up to 100 mM. Experiments on sodium channel inactivation kinetics were performed using 4-aminopyridine to block potassium currents. Sodium currents decayed with a time course generally fit well by a single exponential. The time constant of decay was a steep function of voltage, especially in the negative resistance region of the peak current vs voltage relation.The time course of inactivation was very similar to that of the decay of the current at the same potential. The measurement of steady-state inactivation curves with different test pulses showed no shifts along the voltage asix. The voltage-dependence of the integral of sodium conductance was measured to test models of sodium channel inactivation in which channels must open before inactivating; the results appear inconsistent with some of the simplest cases of such models.

  10. Putative pacemakers in the eyestalk and brain of the crayfish Procambarus clarkii show circadian oscillations in levels of mRNA for crustacean hyperglycemic hormone.

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    Janikua Nelson-Mora

    Full Text Available Crustacean hyperglycemic hormone (CHH synthesizing cells in the optic lobe, one of the pacemakers of the circadian system, have been shown to be present in crayfish. However, the presence of CHH in the central brain, another putative pacemaker of the multi-oscillatory circadian system, of this decapod and its circadian transcription in the optic lobe and brain have yet to be explored. Therefore, using qualitative and quantitative PCR, we isolated and cloned a CHH mRNA fragment from two putative pacemakers of the multi-oscillatory circadian system of Procambarus clarkii, the optic lobe and the central brain. This CHH transcript synchronized to daily light-dark cycles and oscillated under dark, constant conditions demonstrating statistically significant daily and circadian rhythms in both structures. Furthermore, to investigate the presence of the peptide in the central brain of this decapod, we used immunohistochemical methods. Confocal microscopy revealed the presence of CHH-IR in fibers and cells of the protocerebral and tritocerebal clusters and neuropiles, particularly in some neurons located in clusters 6, 14, 15 and 17. The presence of CHH positive neurons in structures of P. clarkii where clock proteins have been reported suggests a relationship between the circadian clockwork and CHH. This work provides new insights into the circadian regulation of CHH, a pleiotropic hormone that regulates many physiological processes such as glucose metabolism and osmoregulatory responses to stress.

  11. Supplementation of Carrot (Daucus carrota as Natural Source of Beta-carotene prepared by Several Methods in Feed to Increase Blue Colour of Freshwater Crayfish Red Claw (Cherax quadricarinatus

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    Woro H. Satyantini

    2012-02-01

    Full Text Available Red claw (Cherax quadricarinatus is one kind of freshwater crayfish that can cultured as consumption or ornamental fish commodities.  The colour of body was important character for performance of red claw as ornamental fish commodity.  Red claw with blue body colour is more expensive than brown.  The purpose of  this experiment was to know the influence addition of carrot with several methods in feed on blue colour  of freshwater crayfish red claw and which was the best preparation method to increase blue colour of freshwater crayfish red claw. The experiment used Completely Randomized Design with four treatments: A (control, B (extract, C (juice and D (shreeded of carrot with 45 ppm dose and five time replicates.  Data was analysed with Kruskal-Wallis and continued with Z test. Result of the experiment was showed that addition of carrot as natural source of beta-carotene with several preparation in feed increase significantly (P Keywords: freshwater crayfish, colour of red claw, carrot, beta-carotene   ABSTRAK Red claw (Cherax quadricarinatus adalah salah satu jenis lobster air tawar yang dapat dibudidayakan sebagai komoditas konsumsi maupun hias.  Sebagai komoditas ikan hias, warna tubuh merupakan karakter penting untuk menunjang penampilan red claw.  Red claw ukuran konsumsi yang memiliki warna biru akan memiliki nilai jual yang lebih tinggi daripada red claw berwarna coklat.  Tujuan penelitian ini untuk mengetahui pengaruh penambahan wortel sebagai sumber beta karoten alami dengan beberapa metoda pengolahan pada pakan terhadap peningkatan warna biru lobster red claw. Penelitian menggunakan Rancangan Acak Lengkap dengan 4 perlakuan : A (kontrol, B (ekstrak, C (jus dan D (serutan wortel dengan menggunakan dosis 45 ppm beta karoten dan ulangan 5 kali.  Data dianalisis dengan uji Kruskal-Wallis dan dilanjutkan dengan uji Z.  Hasil penelitian menunjukkan bahwa penambahan wortel sebagai sumber beta karoten alami dengan beberapa metode

  12. Heat death in the crayfish Austropotamobius pallipes: thermal inactivation of muscle membrane-bound ATPases in warm and cold adapted animals

    Energy Technology Data Exchange (ETDEWEB)

    Gladwell, R T

    1976-01-01

    The thermal sensitivity of the membrane-bound Mg/sup 2 +/ and Na/sup +/ + K/sup +/ + Mg/sup 2 +/ ATPases from the abdominal flexor muscles of 10 and 25/sup 0/C acclimated animals was investigated. The Mg/sup 2 +/ ATPase was inactivated by milder heat treatments than the Na/sup +/ + K/sup +/ + Mg/sup 2 +/ ATPase. The effect of high lethal temperatures on the Mg/sup 2 +/ ATPase was dependent on the previous thermal history of the animal, the enzyme preparations from 10/sup 0/C acclimated animals being more sensitive than those from 25/sup 0/C acclimated animals. The thermal sensitivity of the Na/sup +/ + K/sup +/ + Mg/sup 2 +/ ATPase was not altered by temperature acclimation. The change in the thermal sensitivity of the Mg/sup 2 +/ ATPase with the acclimation temperature of the whole animal was correlated with the survival times of 10 and 25/sup 0/C acclimated animals. The K/sub m/ and V/sub max/ of the ATPases was investigated and the K/sub m/ of both enzymes was found to decrease with acclimation of the whole animal to lower temperatures, so that enzyme/substrate affinity increased with cold acclimation. It was concluded that the inactivation of the muscle Mg/sup 2 +/ ATPase was the primary lesion of heat death in the crayfish, and that the changes in the kinetic properties of the ATPases were an important mechanism in the process of physiological temperature acclimation.

  13. Comparative molecular analyses of select pH- and osmoregulatory genes in three freshwater crayfish Cherax quadricarinatus, C. destructor and C. cainii

    Directory of Open Access Journals (Sweden)

    Muhammad Y. Ali

    2017-08-01

    Full Text Available Systemic acid-base balance and osmotic/ionic regulation in decapod crustaceans are in part maintained by a set of transport-related enzymes such as carbonic anhydrase (CA, Na+/K+-ATPase (NKA, H+-ATPase (HAT, Na+/K+/2Cl− cotransporter (NKCC, Na+/Cl−/HCO ${}_{3}^{-}$ 3 − cotransporter (NBC, Na+/H+ exchanger (NHE, Arginine kinase (AK, Sarcoplasmic Ca+2-ATPase (SERCA and Calreticulin (CRT. We carried out a comparative molecular analysis of these genes in three commercially important yet eco-physiologically distinct freshwater crayfish, Cherax quadricarinatus, C. destructor and C. cainii, with the aim to identify mutations in these genes and determine if observed patterns of mutations were consistent with the action of natural selection. We also conducted a tissue-specific expression analysis of these genes across seven different organs, including gills, hepatopancreas, heart, kidney, liver, nerve and testes using NGS transcriptome data. The molecular analysis of the candidate genes revealed a high level of sequence conservation across the three Cherax sp. Hyphy analysis revealed that all candidate genes showed patterns of molecular variation consistent with neutral evolution. The tissue-specific expression analysis showed that 46% of candidate genes were expressed in all tissue types examined, while approximately 10% of candidate genes were only expressed in a single tissue type. The largest number of genes was observed in nerve (84% and gills (78% and the lowest in testes (66%. The tissue-specific expression analysis also revealed that most of the master genes regulating pH and osmoregulation (CA, NKA, HAT, NKCC, NBC, NHE were expressed in all tissue types indicating an important physiological role for these genes outside of osmoregulation in other tissue types. The high level of sequence conservation observed in the candidate genes may be explained by the important role of these genes as well as potentially having a number of other basic

  14. Comparative molecular analyses of select pH- and osmoregulatory genes in three freshwater crayfish Cherax quadricarinatus, C. destructor and C. cainii.

    Science.gov (United States)

    Ali, Muhammad Y; Pavasovic, Ana; Dammannagoda, Lalith K; Mather, Peter B; Prentis, Peter J

    2017-01-01

    Systemic acid-base balance and osmotic/ionic regulation in decapod crustaceans are in part maintained by a set of transport-related enzymes such as carbonic anhydrase (CA), Na + /K + -ATPase (NKA), H + -ATPase (HAT), Na + /K + /2Cl - cotransporter (NKCC), Na + /Cl - /HCO[Formula: see text] cotransporter (NBC), Na + /H + exchanger (NHE), Arginine kinase (AK), Sarcoplasmic Ca +2 -ATPase (SERCA) and Calreticulin (CRT). We carried out a comparative molecular analysis of these genes in three commercially important yet eco-physiologically distinct freshwater crayfish , Cherax quadricarinatus, C. destructor and C. cainii , with the aim to identify mutations in these genes and determine if observed patterns of mutations were consistent with the action of natural selection. We also conducted a tissue-specific expression analysis of these genes across seven different organs, including gills, hepatopancreas, heart, kidney, liver, nerve and testes using NGS transcriptome data. The molecular analysis of the candidate genes revealed a high level of sequence conservation across the three Cherax sp. Hyphy analysis revealed that all candidate genes showed patterns of molecular variation consistent with neutral evolution. The tissue-specific expression analysis showed that 46% of candidate genes were expressed in all tissue types examined, while approximately 10% of candidate genes were only expressed in a single tissue type. The largest number of genes was observed in nerve (84%) and gills (78%) and the lowest in testes (66%). The tissue-specific expression analysis also revealed that most of the master genes regulating pH and osmoregulation (CA, NKA, HAT, NKCC, NBC, NHE) were expressed in all tissue types indicating an important physiological role for these genes outside of osmoregulation in other tissue types. The high level of sequence conservation observed in the candidate genes may be explained by the important role of these genes as well as potentially having a number of

  15. PcToll3 was involved in anti-Vibrio response by regulating the expression of antimicrobial peptides in red swamp crayfish, Procambarus clarkii.

    Science.gov (United States)

    Lan, Jiang-Feng; Wei, Shun; Wang, Yu-Qing; Dai, Yun-Jia; Tu, Jia-Gang; Zhao, Li-Juan; Li, Xin-Cang; Qin, Qi-Wei; Chen, Nan; Lin, Li

    2016-10-01

    Tolls and Toll-like receptors (TLRs) play an important role in host immune defenses by regulating the expression of antimicrobial peptides (AMPs) and cytokines, but the functional differences of crustacean Tolls from Drosophila Tolls or Mammal TLRs are largely unknown. A novel Toll receptor, named PcToll3, was identified from red swamp crayfish, Procambarus clarkii. It was widely expressed in all detected tissues, and its transcript in hemocytes was up-regulated at 12 h after Vibrio parahemolyticus (Vibrio) injection or at 24 h post white spot syndrome virus (WSSV) challenge. After knockdown of PcToll3, the activity of bacterial clearance was inhibited, and the expression levels of AMPs including Crustin1 (Cru1), Anti-lippopolysaccharide factor 1 (ALF1), and Lysozymes1 (Lys1), which could be up-regulated by Vibrio, were all affected. Meanwhile, PcToll3 silencing influenced the expression of myeloid differentiation factor 88 (PcMyd88), tumor necrosis factor-associated factor 6 (PcTRAF6), and PcDorsal, which were the counterparts of Drosophila Toll signaling pathway. Interestingly, PcToll3 silencing inhibited translocation of PcDorsal from cytoplasm to nucleus. Furthermore, the knockdown of PcDorsal also impaired the expression of AMPs after Vibrio challenge. Hence, we concluded that, besides participating in antiviral immunity, PcToll3 might also regulate the expression of Cru1 and Lys1 to participate in anti-Vibrio immune responses by promoting PcDorsal translocation into nucleus. Copyright © 2016 Elsevier Ltd. All rights reserved.

  16. Comparison of the response (in terms of accumulation, cellular and genetic impacts) of the crayfish Procambarus clarkii after exposure to a metallic pollutant (cadmium) and to a radiological pollutant (uranium 238 and 233)

    International Nuclear Information System (INIS)

    Al Kaddissi, S.

    2012-01-01

    The study of the effects of radionuclides and metals on organisms is necessary for the evaluation of their toxicity and their ecological threats. We first aimed to study the impacts of cadmium (Cd) and Uranium (U) on different biological levels of the crayfish Procambarus clarkii after acute and chronic exposures. We evaluated their impacts on mitochondria, oxidative stress responses, on histological structures, and the survival rates. We tried to connect these effects between them and to the bioaccumulation in the gills and the hepato pancreas. We also tried to discriminate the chemo and the radiotoxicity of U by exposing crayfish to either depleted or enriched U ( 233 U: presenting a higher specific activity) using the same criteria of effects. We demonstrated that the gene mt encoding for the metallothionein was always over-expressed in the presence of Cd. Therefore, it seems to be a good bio-marker of Cd toxicity in P. clarkii. The follow up of mitochondrial genes expressions (12s, atp6 and cox1), showed that both metals affect mitochondria and that their mechanisms of action do not seem to be always the same. We also observed that U generates more oxidative stress than Cd when comparing the expression levels of genes encoding for antioxidants (sod (Mn) and mt) and the enzymatic activities of superoxide dismutase, the catalase, the glutathione peroxidase and the glutathione S transferase. However, the symptoms of histo-pathological damages after Cd and U contamination were similar in both conditions. After comparing the survival rates of the crayfish, we concluded that Cd was more toxic than the radioelement. Moreover, we demonstrated that the toxic effect of U on P. clarkii exposed to a low environmental concentration is mainly due to its chemo-toxicity rather than to its radiotoxicity. We established that, the molecular answers vary according to the intensity and the duration of the chemical stress applied to the organisms. We suggested the use of the

  17. Regina rigida (glossy crayfish snake)

    Science.gov (United States)

    David A. Steen; James A. Stiles; Sierra H. Stiles; Craig Guyer; Josh B. Pierce; D. Craig Rudolph; Lora L. Smith

    2011-01-01

    The overland movements and upland habitat use of wetland-associated reptiles has important conservation implications (Semlitsch and Bodie 2003. Conserv. BioI. 17:1219-1228). However, for many species, particularly snakes, we lack a basic understanding of spatial ecology and habitat use. Regina rigida is a poorly known species for which "observations of any kind...

  18. Sensory Systems and Environmental Change on Behavior during Social Interactions

    Directory of Open Access Journals (Sweden)

    S. M. Bierbower

    2013-01-01

    Full Text Available The impact of environmental conditions for transmitting sensory cues and the ability of crayfish to utilize olfaction and vision were examined in regards to social interactive behavior. The duration and intensity of interactions were examined for conspecific crayfish with different sensory abilities. Normally, vision and chemosensory have roles in agonistic communication of Procambarus clarkii; however, for the blind cave crayfish (Orconectes australis packardi, that lack visual capabilities, olfaction is assumed to be the primary sensory modality. To test this, we paired conspecifics in water and out of water in the presence and absence of white light to examine interactive behaviors when these various sensory modalities are altered. For sighted crayfish, in white light, interactions occurred and escalated; however, when the water was removed, interactions and aggressiveness decreased, but, there was an increase in visual displays out of the water. The loss of olfaction abilities for blind cave and sighted crayfish produced fewer social interactions. The importance of environmental conditions is illustrated for social interactions among sighted and blind crayfish. Importantly, this study shows the relevance in the ecological arena in nature for species survival and how environmental changes disrupt innate behaviors.

  19. Crecimiento del camarón excavador Parastacus pugnax (Poeppig, 1835 determinado mediante técnica de marcaje Growth of burrowing crayfish Parastacus pugnax (Poeppig, 1835 determined by marking technique

    Directory of Open Access Journals (Sweden)

    Mauricio Ibarra

    2011-07-01

    Full Text Available Para determinar el crecimiento en el camarón excavador (Parastacus pugnax en la zona centro sur de Chile se utilizó un marbete tipo cinturón. Los parámetros longitud cefalotorácica asintótica (Lc m y la velocidad de incremento en longitud y peso (K, se establecieron mediante el método de Gulland & Holt (1959. El parámetro t0 se determinó mediante la ecuación inversa del modelo de von Bertalanffy, estableciéndose que las curvas de crecimiento en longitud y peso fueron definidas por los parámetros K = 0,35 mm año-1, t0 = -0,38 años, Lc∞ = 55, 9 mm y W∞ = 83,8 g, valores similares a los de Samastacus spinifrons, especie chilena de alto potencial de cultivo, y de otros parastácidos sudamericanos, tales como P. brasiliensis y P. deffosus.A modified tag belt type was used in the burrowing crayfish (Parastacus pugnax, in the central-south of Chile. The parameters asymptotic carapace length (Lc0 and rate of increase (K were determined through the Gulland & Holt (1959 method. The parameter t0 was determined by the inverse equation of von Bertalanffy model, which allowed to establish that the growth curves in length and weight are defined by the parameters K = 0.35 mm yr-1, t0 = -0.38 years, Lc∞ = 55. 9 mm and W∞= 83.8 g. These values were similar to those of Samastacus spinifrons, Chilean species with high potential for aquaculture, and similar to those of other South American parastacids such as P. brasiliensis and P. deffosus.

  20. Aspectos reproductivos del acocil Cambarellus (Cambarellus montezumae (Crustacea: Decápoda: Cambaridae en condiciones controladas Breeding aspects of the crayfish Cambarellus (Cambarellus montezumae (Crustacea: Decapoda: Cambaridae under controlled conditions

    Directory of Open Access Journals (Sweden)

    José Luis Arredondo-Figueroa

    2011-03-01

    Full Text Available El acocil Cambarellus (C. montezumae es una especie endémica cuya distribución está restringida a algunos cuerpos de agua lacustre. Se presentan los resultados sobre aspectos reproductivos de esta especie en condiciones controladas, con el objetivo de determinar la factibilidad de la producción de huevos y juveniles y su potencial aplicación a programas de rescate, repoblación y cultivo. Se realizaron 2 ensayos experimentales, el primero en 4 estanques exteriores de 800 litros conectados a sistemas cerrados de recirculación (SCR y el segundo en recipientes de plástico en laboratorio (RPL, de 2 litros. Para el primer ensayo, se manejaron 219 reproductores durante 335 días, obteniendo 136 hembras ovígeras. Cada hembra produjo en promedio 45 ± 23 huevos por puesta. El 83.7% de los huevos eclosionaron, obteniéndose un total de 3 162 juveniles. En los RPL se manejó una población F1 obtenida a partir de los reproductores del SCR en una relación 1 hembra: 2 machos, con 10 repeticiones. La producción de huevo fue variable con un promedio de 34 por hembra. Los indicadores de desempeño mostraron diferencias significativas (P ≤ 0.05 entre sexos con respecto a 6 de ellos. Los resultados indican la factibilidad para su cultivo y producción de huevos y juveniles.Cambarellus (C. montezumae is an endemic crayfish from Mexico, which actual distribution is restricted to few lacustrine bodies of water. Here we present results on the reproduction of this species under controlled conditions with the aim to determine the feasibility of the production of eggs and juveniles, as an strategy for their rescue, re-population and culture. Two experimental assays were conducted, the first one, in 4 outdoor 800-L tanks recirculation aquaculture systems (RAS and the second, in 2-L plastic containers under laboratory conditions (PCL. For the first assay, 219 brooders were used during 335 days , obtaining 136 ovigerous females. Each female produced an average

  1. Interactions of bullfrog tadpole predators and an insecticide: Predation release and facilitation

    Science.gov (United States)

    Boone, M.D.; Semlitsch, R.D.

    2003-01-01

    The effect of a contaminant on a community may not be easily predicted, given that complex changes in food resources and predator-prey dynamics may result. The objectives of our study were to determine the interactive effects of the insecticide carbaryl and predators on body size, development, survival, and activity of tadpoles of the bullfrog (Rana catesbeiana). We conducted the study in cattle tank mesocosm ponds exposed to 0, 3.5, or 7.0 mg/l carbaryl, and no predators or two red-spotted newts (Notophthalmus viridescens), bluegill sunfish (Lepomis macrochirus), or crayfish (Orconectes sp.). Carbaryl negatively affected predator survival by eliminating crayfish from all ponds, and by eliminating bluegill sunfish from ponds exposed to the highest concentration of carbaryl; carbaryl exposure did not effect survival of red-spotted newts. Because crayfish were eliminated by carbaryl, bullfrogs were released from predation and survival was near that of predator controls at low concentrations of carbaryl exposure. High concentrations of carbaryl reduced tadpole survival regardless of whether predators survived carbaryl exposure or not. Presence of crayfish and newts reduced tadpole survival, while bluegill sunfish appeared to facilitate bullfrog tadpole survival. Presence of carbaryl stimulated bullfrog tadpole mass and development. Our study demonstrates that the presence of a contaminant stress can alter community regulation by releasing prey from predators that are vulnerable to contaminants in some exposure scenarios.

  2. Are rapid transitions between invasive and native species caused by alternative stable states, and does it matter?

    Science.gov (United States)

    Hansen, Gretchen J A; Ives, Anthony R; Vander Zanden, M Jake; Carpenter, Stephen R

    2013-10-01

    Rapid transitions in ecosystem structure, or regime shifts, are a hallmark of alternative stable states (ASS). However, regime shifts can occur even when feedbacks are not strong enough to cause ASS. We investigated the potential for ASS to explain transitions between dominance of an invasive species, rusty crayfish (Orconectes rusticus), and native sunfishes (Lepomis spp.) in northern Wisconsin (USA) lakes. A rapid transition from Lepomis to rusty crayfish dominance occurred as rusty crayfish invaded Trout Lake, and the reverse transition resulted from an eight-year experimental removal of rusty crayfish from Sparkling Lake. We fit a stage-structured population model of species interactions to 31 years of time-series data from each lake. The model identified water level as an important driver, with drought conditions reducing rusty crayfish recruitment and allowing Lepomis dominance. The maximum-likelihood parameter estimates of the negative interaction between rusty crayfish and Lepomis led to ASS in the model, where each species was capable of excluding the other within a narrow range of environmental conditions. However, uncertainty in parameter estimates made it impossible to exclude the potential that rapid transitions were caused by a simpler threshold response lacking alternative equilibria. Simulated forward and backward transitions between species dominance occurred at different environmental conditions (i.e., hysteresis), even when the parameters used for simulation did not predict ASS as a result of slow species responses to environmental drivers. Thus, ASS are possible, but by no means certain, explanations for rapid transitions in this system, and our results highlight the difficulties associated with distinguishing ASS from other types of threshold responses. However, whether regime shifts are caused by ASS may be relatively unimportant in this system, as the range of conditions over which transitions occur is narrow, and under most conditions, the

  3. Earliest evidence for human consumption of crayfish

    Czech Academy of Sciences Publication Activity Database

    Patoka, J.; Nývltová Fišáková, Miriam; Kalous, L.; Škrdla, Petr; Kuča, M.

    2014-01-01

    Roč. 87, č. 13 (2014), s. 1578-1585 ISSN 0011-216X Institutional research plan: CEZ:AV0Z80010507 Institutional support: RVO:68081758 Keywords : Crustaceans * anthropology of food * consumption * Small game * Neolithic Subject RIV: AC - Archeology, Anthropology, Ethnology Impact factor: 0.473, year: 2014

  4. Relación biogeográfica entre cangrejos dulceacuícolas y acociles a lo largo de la zona mexicana de transición: revaluación de la hipótesis de Rodríguez (1986 Biogeographic relationship of freshwater crabs and crayfish along the Mexican transition zone: reevaluating Rodríguez (1986 hypothesis

    Directory of Open Access Journals (Sweden)

    Fernando Álvarez

    2012-12-01

    Full Text Available A partir de la hipótesis planteada por Rodríguez (1986 sobre una posible exclusión biogeográfica entre acociles de la familia Cambaridae y cangrejos de agua dulce de la familia Pseudothelphusidae a lo largo del centro y sur de México, se han hecho varios estudios que toman en cuenta este patrón. Sin embargo, no se han examinado los patrones de distribución de estos grupos ni cuáles son las zonas ni a qué grado se da el traslape o contacto de las 2 distribuciones. Se construyeron 2 bases de datos, una con más de 1 400 registros de las especies de la familia Cambaridae y otra con más de 400 registros de cangrejos de la familia Pseudothelphusidae. Se construyeron mapas de distribución y se identificaron 3 regiones donde el contacto es evidente: el eje neovolcánico, la región de Los Tuxtlas, Veracruz y el estado de Chiapas. Los resultados muestran grandes zonas de contacto en las cuales tanto acociles como cangrejos pueden estar en la misma localidad y en el mismo cuerpo de agua o pueden estar en 2 localidades muy cercanas pero con una diferencia altitudinal. En general, los acociles tienden a distribuirse a mayores altitudes que los cangrejos. Aunado a los patrones de distribución, se discute que aunque los 2 grupos estén presentes en la misma localidad y en el mismo cuerpo de agua, el microhábitat que ocupa cada uno es distinto, por lo que se sugiere que la interferencia entre ellos será poca o nula.After Rodríguez (1986 hypothesis on the possible biogeographic exclusion between crayfish of the family Cambaridae and freshwater crabs of the family Pseudothelphusidae throughout central and southern Mexico, several studies have considered it as a real pattern. However, the distribution patterns of both groups have not been examined, nor in what areas and to what extent the overlap of the 2 distributions occurs. Two data bases were compiled, one with more than 1 400 records of the species of the family Cambaridae and a second one

  5. Crayfish in Czech cultural space: the longest documented relationship between humans and crayfish in Europe

    Czech Academy of Sciences Publication Activity Database

    Patoka, J.; Kocánová, Barbora; Kalous, L.

    2016-01-01

    Roč. 417, č. 5 (2016), s. 1-9 ISSN 1961-9502 Institutional support: RVO:67985955 Keywords : Freshwater invertebrate * exploitation * history * aquaculture * Czech Republic Subject RIV: AB - History Impact factor: 1.217, year: 2016 https://www.kmae-journal.org/articles/kmae/full_html/2016/01/kmae150112/kmae150112.html

  6. Fatty acids and astaxanthin composition of two edible native Mexican crayfish Cambarellus (C.) montezumae and Procambarus (M.) bouvieri; Composición de ácidos grasos y astaxantina de dos especies comestibles de acociles nativos de México, Cambarellus (C.) montezumae y Procambarus.

    Energy Technology Data Exchange (ETDEWEB)

    Coral-Hinostroza, G.; Diaz-Martinez, M.; Huberman, A.; Silencio-Barrita, J.L.

    2016-07-01

    The content and composition of the fatty acids (F As) and astaxanthin (AST) in the edible forms of crayfish: the whole animal of Cambarellus (C.) montezumae, and the tail meat (TM) of Procambarus (M.) bouvieri were determined by GC and HPLC. The exoskeleton (EXK) of P. (M.) bouvieri was also studied. Unsaturated FAs, and mostly oleic acid (C18:1 n-9), were predominant in both edible forms. The contents of the polyunsaturated eicosapentaenoic (C20:5 n-3, EPA), arachidonic (C20:4 n-6, ARA) and docosahexaenoic acid (C22:6 n-3, DHA), were higher in the TM of P. (M.) bouvieri than in the complete C. (C.) montezumae (p<0.05). Total carotenoids ranged between 2.31 ± 0.33 μg·g−1 and 66.3 ± 3.91 μg·g−1, and were composed mainly of AST (>79.50%). AST esters were enriched with saturated FAs in C. (C.) montezumae and with PUFAs in EXK of P. (M.) bouvieri. We conclude that both C. (C.) montezumae and the TM of P. (M.) bouvieri are traditional foods rich in n-3 PUFAs and C. (C.) montezumae in AST. The EXK of P. (M.) bouvieri is a rich potential source of AST, n-3 PUFAs, and the combination AST-DHA. [Spanish] Se determinó por GC y HPLC el contenido y composición de ácidos grasos (AGs) y astaxantina (AST), en dos formas comestibles de acocil: el animal completo de Cambarellus (C.) montezumae, y el músculo de la cola (MC) de Procambarus (M.) bouvieri. Adicionalmente, se estudió el exosqueleto (EXK) de P. (M.) bouvieri. En ambas formas comestibles predominaron los AGs insaturados. Los contenidos de ácido eicosapentaenoico (C20:5 n-3, EPA), araquidónico (C20:4 n-6, ARA) y docosahexaenoico (C22: 6 n-3, DHA), fueron mayores en el MC que en C. (C) montezumae (p<0,05). Los carotenoides totales oscilaron de 2.3 ± 0.3 μg·g−1 a 66.3 ± 3.9 μg·g−1, con predominancia de AST (>79.50%). Los ésteres de AST en C. (C.) montezumae fueron enriquecidos con AGs saturados mientras que los del EXK de P. (M.) bouvieri con AGs poliinsaturados. Se concluyó que tanto C. (C

  7. parasites of crayfish (p. clarki) and lobsters (macrobrachium

    African Journals Online (AJOL)

    PROF. BARTH EKWEME

    METALLIC POLLUTION IN GREAT, KWA RIVER, NIGERIA. J. T. ABRAHAM .... Atlantic Coastal waters of South Eastern Nigeria. GKR ..... rocks and across thick forest at its origin (Oban Hills). .... Risk Assessment of Heavy Metals in Great Kwa.

  8. Responses of crayfish photoreceptor cells following intense light adaptation.

    Science.gov (United States)

    Cummins, D R; Goldsmith, T H

    1986-01-01

    After intense orange adapting exposures that convert 80% of the rhodopsin in the eye to metarhodopsin, rhabdoms become covered with accessory pigment and appear to lose some microvillar order. Only after a delay of hours or even days is the metarhodopsin replaced by rhodopsin (Cronin and Goldsmith 1984). After 24 h of dark adaptation, when there has been little recovery of visual pigment, the photoreceptor cells have normal resting potentials and input resistances, and the reversal potential of the light response is 10-15 mV (inside positive), unchanged from controls. The log V vs log I curve is shifted about 0.6 log units to the right on the energy axis, quantitatively consistent with the decrease in the probability of quantum catch expected from the lowered concentration of rhodopsin in the rhabdoms. Furthermore, at 24 h the photoreceptors exhibit a broader spectral sensitivity than controls, which is also expected from accumulations of metarhodopsin in the rhabdoms. In three other respects, however, the transduction process appears to be light adapted: The voltage responses are more phasic than those of control photoreceptors. The relatively larger effect (compared to controls) of low extracellular Ca++ (1 mmol/l EGTA) in potentiating the photoresponses suggests that the photoreceptors may have elevated levels of free cytoplasmic Ca++. The saturating depolarization is only about 30% as large as the maximal receptor potentials of contralateral, dark controls, and by that measure the log V-log I curve is shifted downward by 0.54 log units.(ABSTRACT TRUNCATED AT 250 WORDS)

  9. Exposure Through Runoff and Ground Water Contamination Differentially Impact Behavior and Physiology of Crustaceans in Fluvial Systems.

    Science.gov (United States)

    Steele, Alexandra N; Belanger, Rachelle M; Moore, Paul A

    2018-06-19

    Chemical pollutants enter aquatic systems through numerous pathways (e.g., surface runoff and ground water contamination), thus associating these contaminant sources with varying hydrodynamic environments. The hydrodynamic environment shapes the temporal and spatial distribution of chemical contaminants through turbulent mixing. The differential dispersal of contaminants is not commonly addressed in ecotoxicological studies and may have varying implications for organism health. The purpose of this study is to understand how differing routes of exposure to atrazine alter social behaviors and physiological responses of aquatic organisms. This study used agonistic encounters in crayfish Orconectes virilis as a behavioral assay to investigate impact of sublethal concentrations of atrazine (0, 40, 80, and 160 µg/L) delivered by methods mimicking ground water and surface runoff influx into flow-through exposure arenas for a total of 23 h. Each experimental animal participated in a dyadic fight trial with an unexposed opponent. Fight duration and intensity were analyzed. Experimental crayfish hepatopancreas and abdominal muscle tissue samples were analyzed for cytochrome P450 and acetylcholinesterase levels to discern mechanism of detoxification and mode of action of atrazine. Atrazine delivered via runoff decreased crayfish overall fight intensity and contrastingly ground water delivery increased overall fight intensity. The behavioral differences were mirrored by increases in cytochrome P450 activity, whereas no differences were found in acetylcholinesterase activity. This study demonstrates that method of delivery into fluvial systems has differential effects on both behavior and physiology of organisms and emphasizes the need for the consideration of delivery pathway in ecotoxicological studies and water-impairment standards.

  10. Spatial distribution of radionuclides in Lake Michigan biota near the Big Rock Point Nuclear Plant

    International Nuclear Information System (INIS)

    Wahlgren, M.A.; Yaguchi, E.M.; Nelson, D.M.; Marshall, J.S.

    1974-01-01

    A survey was made of four groups of biota in the vicinity of the Big Rock Point Nuclear Plant near Charlevoix, Michigan, to determine their usefulness in locating possible sources of plutonium and other radionuclides to Lake Michigan. This 70 MW boiling-water reactor, located on the Lake Michigan shoreline, was chosen because its fuel contains recycled plutonium, and because it routinely discharges very low-level radioactive wastes into the lake. Samples of crayfish (Orconectes sp.), green algae (Chara sp. and Cladophora sp.), and an aquatic macrophyte (Potamogeton sp.) were collected in August 1973, at varying distances from the discharge and analyzed for 239 240 Pu, 90 Sr, and five gamma-emitting radionuclides. Comparison samples of reactor waste solution have also been analyzed for these radionuclides. Comparisons of the spatial distributions of the extremely low radionuclide concentrations in biota clearly indicated that 137 Cs, 134 Cs, 65 Zn, and 60 Co were released from the reactor; their concentrations decreased exponentially with increasing distance from the discharge. Conversely, concentrations of 239 240 Pu, 95 Zr, and 90 Sr showed no correlation with distance, suggesting any input from Big Rock was insignificant with respect to the atmospheric origin of these isotopes. The significance of these results is discussed, particularly with respect to current public debate over the possibility of local environmental hazards associated with the use of plutonium as a nuclear fuel. (U.S.)

  11. Predictions of marbled crayfish establishment in conurbations fulfilled: Evidences form the Czech republic

    Czech Academy of Sciences Publication Activity Database

    Patoka, J.; Buřič, M.; Kolář, Vojtěch; Bláha, M.; Petrtýl, M.; Franta, P.; Tropek, Robert; Kalous, L.; Petrusek, A.; Kouba, A.

    2016-01-01

    Roč. 71, č. 12 (2016), s. 1380-1385 ISSN 0006-3088 R&D Projects: GA ČR GAP504/12/2525 Grant - others:GA JU(CZ) 158/2016/P; GA MŠk(CZ) LO1205 Institutional support: RVO:60077344 Keywords : Procambarus fallax f. virginalis * biological invasion * first record Subject RIV: EH - Ecology, Behaviour Impact factor: 0.759, year: 2016

  12. Competitive interactions between co-occurring invaders: identifying asymmetries between two invasive crayfish species

    NARCIS (Netherlands)

    Hudina, S.; Galic, N.G.; Roessink, I.; Hock, K.

    2011-01-01

    Ecosystems today increasingly suffer invasions by multiple invasive species. Complex interactions between invasive species can have different fitness implications for each invader, which can in turn determine the future progression of their invasions and result in differential impacts on native

  13. Multiple drivers of decline in the global status of freshwater crayfish (Decapoda:Astacidea)

    Science.gov (United States)

    Nadia I. Richman; Monika Böhm; Susan B. Adams; Fernando Alvarez; Elizabeth A. Bergey; John J. S. Bunn; Quinton Burnham; Jay Cordeiro; Jason Coughran; Keith A. Crandall; Kathryn L. Dawkins; Robert J. DiStefano; Niall E. Doran; Lennart Edsman; Arnold G. Eversole; Leopold Füreder; James M. Furse; Francesca Gherardi; Premek Hamr; David M. Holdich; Pierre Horwitz; Kerrylyn Johnston; Clive M. Jones; Julia P. G. Jones; Robert L. Jones; Thomas G. Jones; Tadashi Kawai; Susan Lawler; Marilu López-Mejía; Rebecca M. Miller; Carlos Pedraza-Lara; Julian D. Reynolds; Alastair M. M. Richardson; Mark B. Schultz; Guenter A. Schuster; Peter J. Sibley; Catherine Souty-Grosset; Christopher A. Taylor; Roger F. Thoma; Jerry Walls; Todd S. Walsh; Ben Cohen

    2015-01-01

    Rates of biodiversity loss are higher in freshwater ecosystems than in most terrestrial or marine ecosystems, making freshwater conservation a priority. However, prioritization methods are impeded by insufficient knowledge on the distribution and conservation status of freshwater taxa, particularly invertebrates. We evaluated the extinction risk of the world’s 590...

  14. Recolonization by warmwater fishes and crayfishes after severe drought in upper coastal plain hill streams

    Science.gov (United States)

    Susan B. Adams; Melvin L. Warren

    2005-01-01

    Extreme hydrologic disturbance, such as a supraseasonal drought, can dramatically influence aquatic communities. Documentation of the responses of aquatic communities after such disturbances provides insight into the timing, order, and mechanisms of recolonization. Postdisturbance recolonization of streams depends on many factors, including the region and...

  15. Founder event and its effect on genetic variation in translocated populations of noble crayfish (Astacus astacus)

    Czech Academy of Sciences Publication Activity Database

    Bláha, M.; Žurovcová, Martina; Kouba, A.; Policar, T.; Kozák, P.

    2016-01-01

    Roč. 57, č. 1 (2016), s. 99-106 ISSN 1234-1983 Grant - others:European Fund(CZ) CZ.1.07/2.3.00/30.0049; European Fund(CZ) CZ1.05/2.1.00/01.0024; GA ČR(CZ) GAP505/12/0545 Institutional support: RVO:60077344 Keywords : bottleneck * conservation * homozygote excess Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 1.655, year: 2016 http://link.springer.com/article/10.1007%2Fs13353-015-0296-3

  16. 76 FR 79209 - Proposed Safe Harbor Agreement for the Shasta Crayfish in Cassel, Shasta County, CA

    Science.gov (United States)

    2011-12-21

    ... nonnative predators and competitors, the Service is working closely with the California Department of Fish... personal identifying information in your comment, you should be aware that your entire comment--including...

  17. Evaluation of processed sweet potato-crayfish – soya bean and ...

    African Journals Online (AJOL)

    The results obtained with diet 3 (sweat potato bambara groundnut mixture) and diet 5 (sweat potato soya bean mixture) compared favourably with the reference diet (Nutrend) in all the parameters examined except for corn starch (diet 7), which recorded lowest values although it contained higher carbohydrate and energy ...

  18. The effect of wind on the rate of heat loss from avian cup-shaped nests.

    Science.gov (United States)

    Heenan, Caragh B; Seymour, Roger S

    2012-01-01

    Forced convection can significantly influence the heat loss from birds and their offspring but effects may be reduced by using sheltered micro-sites such as cavities or constructing nests. The structural and thermal properties of the nests of two species, the spiny-cheeked honeyeater (Acanthagenys rufogularis) and yellow-throated miner (Manorina flavigula), were measured in relation to three wind speeds. Nest dimensions differ between the two species, despite the similar body mass of the incubating adults, however nest conductance is comparable. As wind speed increases, so does the rate of heat loss from the nests of both species, and further still during incubation recesses. The significance of forced convection through the nest is a near-doubling in heat production required by the parent, even when incubating at relatively low wind speeds. This provides confirmation that selecting a sheltered nest site is important for avian reproductive success.

  19. The effect of wind on the rate of heat loss from avian cup-shaped nests.

    Directory of Open Access Journals (Sweden)

    Caragh B Heenan

    Full Text Available Forced convection can significantly influence the heat loss from birds and their offspring but effects may be reduced by using sheltered micro-sites such as cavities or constructing nests. The structural and thermal properties of the nests of two species, the spiny-cheeked honeyeater (Acanthagenys rufogularis and yellow-throated miner (Manorina flavigula, were measured in relation to three wind speeds. Nest dimensions differ between the two species, despite the similar body mass of the incubating adults, however nest conductance is comparable. As wind speed increases, so does the rate of heat loss from the nests of both species, and further still during incubation recesses. The significance of forced convection through the nest is a near-doubling in heat production required by the parent, even when incubating at relatively low wind speeds. This provides confirmation that selecting a sheltered nest site is important for avian reproductive success.

  20. Subcellular localisation of radionuclides by transmission electronic microscopy in aquatic and terrestrial organisms

    Energy Technology Data Exchange (ETDEWEB)

    Floriani, M.; Grasset, G.; Simon, O.; Morlon, H.; Laroche, L. [CEA Cadarache (DEI/SECRE/LRE), Laboratory of Radioecology and Ecotoxicology, Institute for Radioprotection and Nuclear Safety, 13 - Saint-Paul-lez-Durance (France)

    2004-07-01

    The global framework of this study is to go further in the understanding of the involved mechanisms of uranium and selenium internalisation at the subcellular level and of their toxicity towards several aquatic and terrestrial organisms. In this context, the applications and performances of a Scanning Transmission Electron Microscope (TEM/STEM) equipped with CCD camera and Energy-Dispersive- X-Ray (EDAX) analysis are reported. The principal merit of this equipment is the clear expression of element distribution with nanometer resolution. The sample for TEM analysis were prepared in ultrathin sections of 70-140 nm (thickness) and those for EDAX in sections of 200-500 nm. This method offers the possibility of a direct correlation between histological image and distribution map of trace elements. For each sample, following TEM analysis, EDAX spectra or EDAX mapping were also recorded to confirm the identity of the electron dense material in the scanned sections. Demonstration of the usefulness of this method to understand the bioaccumulation mechanisms and to study the effect of the pollutant uptake at the subcellular level was performed for target organs of a metal (U) and a metalloid (Se) in various biological models: a higher rooted plant (Phaseolus vulgaris)) and a freshwater invertebrate (Orconectes Limosus) and a unicellular green alga (Chlamydomonas reinhardtii)). TEM-EDAX analysis revealed the presence of U-deposits in gills and digestive gland in crayfish, and in vacuoles or in the cytoplasm of different rooted cells bean. In the alga, the accumulation of Se was found in electron-dense granules within cytoplasm associated with ultrastructural changes and starch accumulation. (author)

  1. Subcellular localisation of radionuclides by transmission electronic microscopy in aquatic and terrestrial organisms

    International Nuclear Information System (INIS)

    Floriani, M.; Grasset, G.; Simon, O.; Morlon, H.; Laroche, L.

    2004-01-01

    The global framework of this study is to go further in the understanding of the involved mechanisms of uranium and selenium internalisation at the subcellular level and of their toxicity towards several aquatic and terrestrial organisms. In this context, the applications and performances of a Scanning Transmission Electron Microscope (TEM/STEM) equipped with CCD camera and Energy-Dispersive- X-Ray (EDAX) analysis are reported. The principal merit of this equipment is the clear expression of element distribution with nanometer resolution. The sample for TEM analysis were prepared in ultrathin sections of 70-140 nm (thickness) and those for EDAX in sections of 200-500 nm. This method offers the possibility of a direct correlation between histological image and distribution map of trace elements. For each sample, following TEM analysis, EDAX spectra or EDAX mapping were also recorded to confirm the identity of the electron dense material in the scanned sections. Demonstration of the usefulness of this method to understand the bioaccumulation mechanisms and to study the effect of the pollutant uptake at the subcellular level was performed for target organs of a metal (U) and a metalloid (Se) in various biological models: a higher rooted plant (Phaseolus vulgaris)) and a freshwater invertebrate (Orconectes Limosus) and a unicellular green alga (Chlamydomonas reinhardtii)). TEM-EDAX analysis revealed the presence of U-deposits in gills and digestive gland in crayfish, and in vacuoles or in the cytoplasm of different rooted cells bean. In the alga, the accumulation of Se was found in electron-dense granules within cytoplasm associated with ultrastructural changes and starch accumulation. (author)

  2. 226Ra concentrations in crayfish tissues, water, and sediments from the Serpent River Basin in Northeastern Ontario, Canada

    International Nuclear Information System (INIS)

    Alikhan, M.A.

    1996-01-01

    Lower Serpent River, as well as Elliot, McCarthy and McCabe lakes had highest 226 Ra contamination, Chrisman, Quirke and Whiskey lakes a moderate one, Flack and Semiwhite lakes and the 'distant' control, Lake Wanapitei, the lowest. 226 Ra activity in Cambarus robustus tissues was directly related to their background levels. Thus, concentration coefficient (tissue/sediment concentrations) for 226 Ra ranged from 0.53 to 0.74 in highly contaminated Elliot and McCarthy lakes, 0.28 to 0.59 in moderately contaminated Quirke and Whiskey lakes, and from 0.27 to 3.44 in least contaminated Semiwhite and Flack lakes. Among various organs analysed, exoskeleton showed the highest (43.04 - 90.69%) and the tail muscles the lowest (2.95 -17.14%) 226 Ra activity. 226 Ra concentrations in the alimentary canal were considered a part of the ambient environment as they had not been absorbed

  3. Muddied waters: suspended sediment impacts on gill structure and aerobic scope in an endangered native and an invasive freshwater crayfish

    DEFF Research Database (Denmark)

    Rosewarne, P.J.; Svendsen, Jon Christian; Mortimer, R.J.G.

    2014-01-01

    Suspended sediment (SS) loadings in freshwater habitats have increased over the past century and SS is now a significant environmental stressor. Greater tolerance to environmental stressors has been proposed as a factor in the success of aquatic invasive species. Further, parasites may interact...

  4. Determination of chromium in treated crayfish, Procambarus clarkii, by electrothermal ASS: study of chromium accumulation in different tissues

    Energy Technology Data Exchange (ETDEWEB)

    Hernandez, F.; Diaz, J.; Medina, J.; Del Ramo, J.; Pastor, A.

    1986-06-01

    In the present study, the authors investigated the accumulation of chromium in muscle, hepatopancreas, antennal glands, and gills of Procambarus clarkii (Girard) from Lake Albufera following Cr(VI)-exposure. Determinations of chromium were made by using Electrothermal Atomic Absorption Spectroscopy and the standard additions method.

  5. {sup 226}Ra concentrations in crayfish tissues, water, and sediments from the Serpent River Basin in Northeastern Ontario, Canada

    Energy Technology Data Exchange (ETDEWEB)

    Alikhan, M.A. [Laurentian Univ., Sudbury, ON (Canada). Dept of Biology

    1996-12-31

    Lower Serpent River, as well as Elliot, McCarthy and McCabe lakes had highest {sup 226}Ra contamination, Chrisman, Quirke and Whiskey lakes a moderate one, Flack and Semiwhite lakes and the `distant` control, Lake Wanapitei, the lowest. {sup 226}Ra activity in Cambarus robustus tissues was directly related to their background levels. Thus, concentration coefficient (tissue/sediment concentrations) for {sup 226}Ra ranged from 0.53 to 0.74 in highly contaminated Elliot and McCarthy lakes, 0.28 to 0.59 in moderately contaminated Quirke and Whiskey lakes, and from 0.27 to 3.44 in least contaminated Semiwhite and Flack lakes. Among various organs analysed, exoskeleton showed the highest (43.04 - 90.69%) and the tail muscles the lowest (2.95 -17.14%) {sup 226}Ra activity. {sup 226}Ra concentrations in the alimentary canal were considered a part of the ambient environment as they had not been absorbed. 12 refs, 1 fig, 1 tab.

  6. Effects of clothianidin on aquatic communities: Evaluating the impacts of lethal and sublethal exposure to neonicotinoids.

    Science.gov (United States)

    Miles, Jesse C; Hua, Jessica; Sepulveda, Maria S; Krupke, Christian H; Hoverman, Jason T

    2017-01-01

    The widespread usage of neonicotinoid insecticides has sparked concern over their effects on non-target organisms. While research has largely focused on terrestrial systems, the low soil binding and high water solubility of neonicotinoids, paired with their extensive use on the landscape, puts aquatic environments at high risk for contamination via runoff events. We assessed the potential threat of these compounds to wetland communities using a combination of field surveys and experimental exposures including concentrations that are representative of what invertebrates experience in the field. In laboratory toxicity experiments, LC50 values ranged from 0.002 ppm to 1.2 ppm for aquatic invertebrates exposed to clothianidin. However, freshwater snails and amphibian larvae showed high tolerance to the chemical with no mortality observed at the highest dissolvable concentration of the insecticide. We also observed behavioral effects of clothianidin. Water bugs, Belostoma flumineum, displayed a dose-dependent reduction in feeding rate following exposure to clothianidin. Similarly, crayfish, Orconectes propinquus, exhibited reduced responsiveness to stimulus with increasing clothianidin concentration. Using a semi-natural mesocosm experiment, we manipulated clothianidin concentration (0.6, 5, and 352 ppb) and the presence of predatory invertebrates to explore community-level effects. We observed high invertebrate predator mortality with increases in clothianidin concentration. With increased predator mortality, prey survival increased by 50% at the highest clothianidin concentration. Thus, clothianidin contamination can result in a top-down trophic cascade in a community dominated by invertebrate predators. In our Indiana field study, we detected clothianidin (max = 176 ppb), imidacloprid (max = 141 ppb), and acetamiprid (max = 7 ppb) in soil samples. In water samples, we detected clothianidin (max = 0.67 ppb), imidacloprid (max = 0.18 ppb), and thiamethoxam (max = 2

  7. Effects of clothianidin on aquatic communities: Evaluating the impacts of lethal and sublethal exposure to neonicotinoids.

    Directory of Open Access Journals (Sweden)

    Jesse C Miles

    Full Text Available The widespread usage of neonicotinoid insecticides has sparked concern over their effects on non-target organisms. While research has largely focused on terrestrial systems, the low soil binding and high water solubility of neonicotinoids, paired with their extensive use on the landscape, puts aquatic environments at high risk for contamination via runoff events. We assessed the potential threat of these compounds to wetland communities using a combination of field surveys and experimental exposures including concentrations that are representative of what invertebrates experience in the field. In laboratory toxicity experiments, LC50 values ranged from 0.002 ppm to 1.2 ppm for aquatic invertebrates exposed to clothianidin. However, freshwater snails and amphibian larvae showed high tolerance to the chemical with no mortality observed at the highest dissolvable concentration of the insecticide. We also observed behavioral effects of clothianidin. Water bugs, Belostoma flumineum, displayed a dose-dependent reduction in feeding rate following exposure to clothianidin. Similarly, crayfish, Orconectes propinquus, exhibited reduced responsiveness to stimulus with increasing clothianidin concentration. Using a semi-natural mesocosm experiment, we manipulated clothianidin concentration (0.6, 5, and 352 ppb and the presence of predatory invertebrates to explore community-level effects. We observed high invertebrate predator mortality with increases in clothianidin concentration. With increased predator mortality, prey survival increased by 50% at the highest clothianidin concentration. Thus, clothianidin contamination can result in a top-down trophic cascade in a community dominated by invertebrate predators. In our Indiana field study, we detected clothianidin (max = 176 ppb, imidacloprid (max = 141 ppb, and acetamiprid (max = 7 ppb in soil samples. In water samples, we detected clothianidin (max = 0.67 ppb, imidacloprid (max = 0.18 ppb, and

  8. Socioeconomic Determinants of Income From Fresh and Processed ...

    African Journals Online (AJOL)

    A total sample size of 84 crayfish marketers were in all randomly selected across three major Cray ... determine the income derived from fresh crayfish marketing while household size and purchasing ... EMAIL FULL TEXT EMAIL FULL TEXT

  9. Using stable isotope analysis to determine the contribution of naturally occurring pond biota and supplementary feed to the diet of farmed Australian freshwater crayfish, redclaw (Cherax quadricarinatus

    Directory of Open Access Journals (Sweden)

    Melissa K. Joyce

    2015-12-01

    Full Text Available Abstract Nutritional requirements of redclaw (Cherax quadricarinatus farmed in Australia are poorly understood and little is known on what is actively being consumed in semi-intensive pond culture. In this study the isotopic signatures of δ13C and δ15N of potential food sources were analysed with a multi-source mixing model to determine the extent of their contribution to the diet of farmed redclaw. Four commercial redclaw farms in North Queensland, Australia (Mareeba, Biboorha, Wondecla and Topaz were sampled for naturally occurring pond organisms and commonly used supplemental feed such as raw corn, soybean, lupin, commercial redclaw, and chicken feed. Both naturally occurring pond biota and supplemental feed contribute to the tissue composition of redclaw to some degree. However, the contribution varies with the type of feed and availability of natural sources, for example plant material at Topaz Farm was a greater contributor with 43.9 ± 19.5 % compared to supplementary sources raw corn 8.20 ± 3.10 and lupin 1.60 ± 1.70 %. Moreover, some supplemental feeds provided a direct nutrient source for primary pond productivity; contribution of the redclaw pellet to zoo- and phytoplankton at Wondecla Farm was 83.1 ± 6.50 and 50.0 ± 9.50 %, respectively, with similarly high values for chicken feed at Biboorha Farm of 72.6 ± 4.70 and 83.4 ± 6.90 %. The cost effectiveness of such feeds needs to be questioned if these are not being consumed and utilised directly. Providing a species-specific formulated feed with improved water stability would enhance production reliability and facilitate growth within the industry.

  10. An invaded invader: high prevalence of entocytherid ostracods on the red swamp crayfish Procambarus clarkii (Girard, 1852) in the Eastern Iberian Peninsula

    Czech Academy of Sciences Publication Activity Database

    Aguilar-Alberola, J. A.; Mesquita-Joanes, F.; López, S.; Mestre, A.; Casanova, J. C.; Rueda, J.; Ribas, Alexis

    2012-01-01

    Roč. 688, č. 1 (2012), s. 63-73 ISSN 0018-8158 Institutional research plan: CEZ:AV0Z60930519 Keywords : Ostracoda * Commensalism * Alien species * Biological invasion Subject RIV: EG - Zoology Impact factor: 1.985, year: 2012

  11. Euastacus morgani sp. n., a new spiny crayfish (Crustacea, Decapoda, Parastacidae from the highland rainforests of eastern New South Wales, Australia

    Directory of Open Access Journals (Sweden)

    Jason Coughran

    2011-03-01

    Full Text Available Euastacus morgani sp. n., is described from a highland, rainforest site in Bindarri National Park, in eastern New South Wales, Australia. Euastacus morgani is found living sympatrically with two more common species, E. dangadi Morgan, 1997 and E. neohirsutus Riek, 1956. Systematically, the species belongs in the ‘simplex’ complex of the genus that includes E. simplex Riek, 1956, E. clarkae Morgan, 1997, E. maccai McCormack and Coughran 2008 and E. morgani. This new species differs from its nearest congenor, E. simplex, inthree mesial carpal spines. A key to the ‘simplex’ complex is presented.

  12. Protein modification in the post-mating spermatophore of the signal crayfish Pacifastacus leniusculus: insight into the tyrosine phosphorylation in a non-motile spermatozoon

    Czech Academy of Sciences Publication Activity Database

    Niksirat, H.; Vancová, Marie; Andersson, L.; James, P.; Kouba, A.; Kozák, P.

    2016-01-01

    Roč. 172, SEP (2016), s. 123-130 ISSN 0378-4320 R&D Projects: GA TA ČR(CZ) TE01020118 Institutional support: RVO:60077344 Keywords : microtubular radial arm * spermatozoon capacitation * tyrosine-phosphorylation * ultrastructural localization Subject RIV: EA - Cell Biology Impact factor: 1.605, year: 2016

  13. Invertebrate medicine

    National Research Council Canada - National Science Library

    Lewbart, G.A

    2012-01-01

    .... Coverage includes sponges, jellyfish, anemones, corals, mollusks, starfish, sea urchins, crabs, crayfish, lobsters, shrimp, hermit crabs, spiders, scorpions, and many more, with chapters organized by taxonomy...

  14. ROUNDTABLE - SESSION 2 EXPLOITATION, CONSERVATION AND LEGISLATION

    Directory of Open Access Journals (Sweden)

    EDSMAN L.

    2004-01-01

    Full Text Available The link between socioeconomics and conservation and the role of legislation in conservation work was discussed in the group with participants from nine European countries. Interest and knowledge among the general public, stakeholders and managers is the key to successful conservation of native crayfish species. Exploitation and conservation do not necessarily exclude each other. A controlled fishery, where it can be sustained, may be an essential tool for conservation by increasing the general awareness and involving more people in the task of protecting the native crayfish species. This strategy is mainly possible for the noble crayfish in the northern part of its distribution, where strong traditions connected to crayfish also exist. A balance between utilisation and overexploitation has to be found and local guidelines for sustainable exploitation produced. Media, the Internet and educational material aimed at schools and stakeholders are excellent ways of reaching a wide audience with information. Universal objectives, rules and regulations at the European level are desirable and the noble crayfish and the stone crayfish should be included in Annex II of the Habitat Directive. Based on this framework detailed regulations are best worked out at the national level, considering the specific crayfish situation in the country. Information about the legislation, the purpose of the legislation and the consequences when not obeying it should be distributed. Stricter regulation of the trade with live alien crayfish is vital because of the associated risk of introducing new diseases and species.

  15. Aquatic macroinvertebrate responses to native and non-native predators

    Directory of Open Access Journals (Sweden)

    Haddaway N. R.

    2014-01-01

    Full Text Available Non-native species can profoundly affect native ecosystems through trophic interactions with native species. Native prey may respond differently to non-native versus native predators since they lack prior experience. Here we investigate antipredator responses of two common freshwater macroinvertebrates, Gammarus pulex and Potamopyrgus jenkinsi, to olfactory cues from three predators; sympatric native fish (Gasterosteus aculeatus, sympatric native crayfish (Austropotamobius pallipes, and novel invasive crayfish (Pacifastacus leniusculus. G. pulex responded differently to fish and crayfish; showing enhanced locomotion in response to fish, but a preference for the dark over the light in response to the crayfish. P.jenkinsi showed increased vertical migration in response to all three predator cues relative to controls. These different responses to fish and crayfish are hypothesised to reflect the predators’ differing predation types; benthic for crayfish and pelagic for fish. However, we found no difference in response to native versus invasive crayfish, indicating that prey naiveté is unlikely to drive the impacts of invasive crayfish. The Predator Recognition Continuum Hypothesis proposes that benefits of generalisable predator recognition outweigh costs when predators are diverse. Generalised responses of prey as observed here will be adaptive in the presence of an invader, and may reduce novel predators’ potential impacts.

  16. 76 FR 3126 - Final Determination of the Assistant Administrator for Water Pursuant to Section 404(c) of the...

    Science.gov (United States)

    2011-01-19

    ... macroinvertebrates, up to 46 species of amphibians and reptiles, 4 species of crayfish, and 5 species of fish, as... amphibians, reptiles, crayfish, and bird species that depend on downstream waters for food or habitat... be, in turn, substantial effects on fish, amphibian, and bird populations that rely on these...

  17. AN INVESTIGATION INTO THE DISAPPEARANCE OF AUSTROPOTAMOBIUS PALLIPES (LEREBOULLET POPULATIONS IN THE HEADWATERS OF THE NORE RIVER, IRELAND AND THE CORRELATION TO WATER QUALITY

    Directory of Open Access Journals (Sweden)

    LYONS R.

    2003-04-01

    Full Text Available Monitoring of the protected white-clawed crayfish Austropotamobius pallipes (Lereboullet has been carried out in the headwaters of the Nore River since 1995. In recent years a reduction in crayfish abundance had become apparent. Some populations had completely disappeared. Adult crayfish were sampled using the baited trap method while juveniles were sampled using a modified surber sampler. The temporal variation in baited trap data was found to be significant at three of the sites while significant variation in enclosure sampling data was found at two sites. In an effort to ascertain why the populations had disappeared a possible relationship between water quality and adult and juvenile crayfish numbers was investigated. Water quality was assessed using both chemical and macroinvertebrate data. Macroinvertebrate sampling revealed deterioration in water quality at all sites. Results also showed the disappearance of crayfish from both Q3 and Q3-4 waters at some sites yet crayfish remain at these Q-ratings at other sites. Therefore the Q-rating below which crayfish cannot survive cannot clearly be defined. However, no clear correlation was observed between the water chemistry data and the crayfish data. Crayfish populations at the Fertagh (FRT site appear to be surviving intermittent pollution and eutrophic conditions where pre-dawn oxygen sags reach lows of 4.4 mg/l O2. Deterioration in water quality as indicated by the Q-value biotic index coincided with reduced crayfish catches. There is no evidence to suggest that predation be it of aquatic or terrestrial origin is a major contributing factor.

  18. Investigating the genetic and epigenetic basis of big biological ...

    Indian Academy of Sciences (India)

    Günter Vogt

    2018-02-14

    Feb 14, 2018 ... advantage of producing high numbers of genetically identi- cal offspring. ..... For net culture, small containers should be filled to a water level of about ...... The availability of the genome of marbled crayfish now enables further ...

  19. Aphanomyces astaci w Europie wyeliminował populację raków z ...

    African Journals Online (AJOL)

    user

    2013-10-30

    Oct 30, 2013 ... species is a smaller and less frequently encountered genera of the .... studies by Czeczuga et al., (2004a; b) in fish eggs of. European Whitefish ... crayfish, and also fish which are currently endangered in Europe and specially.

  20. Biochemical and Haematological Indices of Weanly Albino Rats Fed ...

    African Journals Online (AJOL)

    acer

    ABSTRACT: Malnutrition is a public health problem in Nigeria accounting for more than 50% of ... weanly albino rats using nutritional, biochemical ... groundnut (16%), soy beans (16%), crayfish ... consumption was observed in rats on PC and.

  1. Diel turbidity cycles in a headwater stream: evidence of nocturnal bioturbation?

    OpenAIRE

    Cooper, Richard J.; Outram, Faye; Hiscock, Kevin M.

    2016-01-01

    Purpose: A small number of recent studies have linked daily cycles in stream turbidity to nocturnal bioturbation by aquatic fauna, principally crayfish, and demonstrated this process can significantly impact upon water quality under baseflow conditions. Adding to this limited body of research, we use high-resolution water quality monitoring data to investigate evidence of diel turbidity cycles in a lowland, headwater stream with a known signal crayfish (Pacifastacus leniusculus) population an...

  2. INTRODUCTION : THE EU-NETWORK CRAYNET- IMPACTS ON FUNDAMENTAL QUESTIONS

    Directory of Open Access Journals (Sweden)

    SOUTY-GROSSET C.

    2005-07-01

    Full Text Available The European network CRAYNET “European crayfish as keystone species-linking science, management and economics with sustainable environmental quality” emphasises knowledge-based management strategies. The CRAYNET meetings concentrate on certain topics: monitoring in conservation and management of natives; interaction between natives and aliens; control of aliens; habitat restoration; reintroduction and restocking; legislation; education. The Irish meeting (Kilkenny, 2003 “The endangered native crayfish Austropotamobius pallipes: bioindicator and heritage species” initiated debates about (1 what is a bioindicator, a flagship species or a heritage species?; (2 the problem of species complexes and the need to clarify and resolve taxonomy before management; and (3 what is meant by biodiversity in the context of European crayfish? The Norwegian meeting (Halden, 2003 “European native, crayfish with a special focus on Astacus astacus: linking socioeconomics and conservation ” involved roundtables about (1 threats to indigenous population of crayfish at a landscape level; (2 exploitation, conservation, legislation; (3 reintroduction of indigenous crayfish, habitat restoration and monitoring; and (4 the urgent need for joint research about pathology. The present meeting (Innsbruck, 2004 “European native crayfish in relation to land-use and habitat deterioration with a special focus on Austropotamobius torrentim” aims to identify the species protection programs, to examine if legislation is working well in protecting vulnerable species, the state of advances about conservation genetics and how to make progress in education of the public. A permanent connection between the 12 core members provides opportunities to check the needed lines of research, to prepare recommendations, and to gather information for an atlas on the distribution of crayfish species in Europe as well as to prepare leaflets for the public.

  3. Hydrological disturbance diminishes predator control in wetlands.

    Science.gov (United States)

    Dorn, Nathan J; Cook, Mark I

    2015-11-01

    Effects of predators on prey populations can be especially strong in aquatic ecosystems, but disturbances may mediate the strength of predator limitation and even allow outbreaks of some prey populations. In a two-year study we investigated the numerical responses of crayfish (Procambarus fallax) and small fishes (Poeciliidae and Fundulidae) to a brief hydrological disturbance in replicated freshwater wetlands with an experimental drying and large predatory fish reduction. The experiment and an in situ predation assay tested the component of the consumer stress model positing that disturbances release prey from predator limitation. In the disturbed wetlands, abundances of large predatory fish were seasonally reduced, similar to dynamics in the Everglades (southern Florida). Densities of small fish were unaffected by the disturbance, but crayfish densities, which were similar across all wetlands before drying, increased almost threefold in the year after the disturbance. Upon re-flooding, juvenile crayfish survival was inversely related to the abundance of large fish across wetlands, but we found no evidence for enhanced algal food quality. At a larger landscape scale (500 km2 of the Everglades), crayfish densities over eight years were positively correlated with the severity of local dry disturbances (up to 99 days dry) during the preceding dry season. In contrast, densities of small-bodied fishes in the same wetlands were seasonally depressed by dry disturbances. The results from our experimental wetland drought and the observations of crayfish densities in the Everglades represent a large-scale example of prey population release following a hydrological disturbance in a freshwater ecosystem. The conditions producing crayfish pulses in the Everglades appear consistent with the mechanics of the consumer stress model, and we suggest crayfish pulses may influence the number of nesting wading birds in the Everglades.

  4. Adaptation of Cambarus bartonii cavatus (Hay) (Decapoda: Cambaridae) to acid mine-polluted waters

    Energy Technology Data Exchange (ETDEWEB)

    Gallaway, M.S.; Hummon, W.D. (Ohio University, Athens, OH (USA). Dept. of Zoological and Biomedical Sciences)

    1991-09-01

    Juvenile crayfish {ital Cambarus bartonii cavatus} were taken from two nearby sites on Big Four Creek, Vinton County, OH. Water from upstream (UpS) and downstream (DnS) sites had total conductivities of 250 {mu}S and 600 {mu}S ({mu}S {mu}mho/cm{sup 2}) at 25{degree}C. Non-carbonate conductivity was largely made up of sulfuric acid and heavy metals. Carbonates represented 40% of the conductivity at UpS but were absent from DnS. With only 100 {mu}S of carbonate buffering capacity, water from UpS had little ability to neutralize acidic input, and this was easily overcome. Tests in seven solutions ranging between 250 {mu}S and 5000 {mu}S showed that: (1) mortality of crayfish was affected by the conductivity of test solutions, (2) DnS crayfish survived longer than UpS crayfish in all test conditions except the clean UpS water, and (3) there was no interaction term between source area and strength of conductivity on longevity. Attempts to acclimate crayfishes to higher levels of mine acid over short time periods were unsuccessful. Crayfish mortality under low acid conditions was not increased by addition of iron precipitate, though deaths were associated with ecdysis at intermediate and higher concentrations of mine acid. If DnS, but not UpS, crayfishes of this subspecies have acclimatized to intermediate concentrations of mine acid, then we infer a regime of semi-isolated reproduction over a short distance of streambed. Such an adaptation might have evolved following long-term exposure to low level, naturally-occurring acid seepage from coal outcrops, with success depending on the pre-adaptation of this subspecies to life in waters that are naturally low in carbonate buffering capacity. 37 refs., 3 tabs.

  5. Direct effects of cold shock: bioassays with three Columbia River organisms

    International Nuclear Information System (INIS)

    Becker, C.D.; Schneider, M.J.

    1975-01-01

    Results of studies of the direct effects of cold shock on the pumpkinseed sunfish (representing a warmwater fish), the rainbow trout (representing a coldwater fish), and the common crayfish showed that resistance to cold shock varies between species, is dependent on acclimation temperature, and resistance to temperature declines is dependent on the decline rate. Severe cold shock at a sublethal level is accompanied by disorientation, loss of equilibrium, and immobilization. Pumpkinseed, the warm water species, are most susceptible. Rainbow, the cold water species, are less susceptible; at an acclimation 10 0 C, rainbow survive abrupt shock to levels slightly above freezing. Crayfish, the decapod crustacean, are most resistant; at an acclimation of 15 0 C, crayfish survive abrupt shock to the point just above freezing

  6. Animals from the Outside In, Science (Experimental): 5314.01.

    Science.gov (United States)

    Kleinman, David Z.

    Presented is an outline of a basic course (low level) in biology for students whose interest and background are very limited. The study and dissection of earthworm, crayfish, perch, and bird are included. A detailed study of the frog is undertaken as a representative of the animal kingdom. Performance objectives are presented, as well as a course…

  7. Journal of Earth System Science | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    These tubes bear mixed characters assignable to both crayfish burrows and large-diameter rhizoliths. Further work on these tubes is necessary to make more accurate interpretations of those structures. Shallow to moderate burrow depths; intermittent, short-lived colonization events and preservation of rhizoliths and ...

  8. Environmental Assessment: Maintenance of the Bear Lake Storm Water Retention Pond Whiteman Air Force Base, Missouri

    Science.gov (United States)

    2010-10-01

    life cycles , provide a natural filter for water quality improvement and supply a source of fresh water and organic materials to downstream waters...associated wetlands have the capacity to contribute hydrology and convey pollutants to receiving waters, provide habitat for aquatic organism life cycles ...insects, spiders and small crayfish . Missouri Distribution: Prairie areas in the northern , central and western sections of Missouri Breeding

  9. Life and work of Dr. Johannes Govertus de Man (1850-1930)

    NARCIS (Netherlands)

    Karssen, G.

    2006-01-01

    This book describes the life and work of Dr. Johannes Govertus de Man (1850-1930), a remarkable Dutch invertebrate zoologist. J.G. de Man worked on the systematics of both the Crustacea, in particular on Decapoda (i.e. crabs, crayfish, lobsters and shrimps), and the microscopically Nematoda or

  10. Biomimetics and astronomical X-ray optics

    Science.gov (United States)

    Hudec, R.; Remisova, K.

    2017-07-01

    Some sea and water animals have strange mirror eyes which have (or might have) potential application in science and technology in general and in X—ray astrophysics in particular. While the principles of mirror eyes of decapods (lobsters, crayfishes) are already applied in space and ground—based imaging experiments, the mirror eyes of specific fishes are still very little investigated.

  11. Nutritional evaluation of the giant grassropper (Zonocerus ...

    African Journals Online (AJOL)

    The biological value of giant grasshopper protein (Zonocerus variegatus) was evaluated by comparing the weight gained, food efficiency ratio (FER), protein efficiency ratio (PER) of rats fed standard laboratory chow with that of rats fed giant grasshopper, Soyabean(Glycine max) and crayfish. The effect of high fibre content ...

  12. Food preferences of captive wild raccoons, Procyon lotor, from east Texas

    Science.gov (United States)

    James F. Taulman; James H. Williamson

    1994-01-01

    We offered a random assortment of six foods to nine captive raccoons (Procyon lotor) during 10 days in February 1991 and to 10 raccoons during 9 days in January 1992; persimmon (Diospyros virginianus); southern red oak acorn (Quercus falacata); chicken egg; crayfish (Cambarus bartoni);...

  13. Biological Diversity, Ecological Health and Condition of Aquatic Assemblages at National Wildlife Refuges in Southern Indiana, USA

    Directory of Open Access Journals (Sweden)

    Thomas Simon

    2015-01-01

    Full Text Available The National Wildlife Refuge system is a vital resource for the protection and conservation of biodiversity and biological integrity in the United States. Surveys were conducted to determine the spatial and temporal patterns of fish, macroinvertebrate, and crayfish populations in two watersheds that encompass three refuges in southern Indiana. The Patoka River National Wildlife Refuge had the highest number of aquatic species with 355 macroinvertebrate taxa, six crayfish species, and 82 fish species, while the Big Oaks National Wildlife Refuge had 163 macroinvertebrate taxa, seven crayfish species, and 37 fish species. The Muscatatuck National Wildlife Refuge had the lowest diversity of macroinvertebrates with 96 taxa and six crayfish species, while possessing the second highest fish species richness with 51 species. Habitat quality was highest in the Muscatatuck River drainage with increased amounts of forested habitats compared to the Patoka River drainage. Biological integrity of the three refuges ranked the Patoka NWR as the lowest biological integrity (mean IBI reach scores = 35 IBI points, while Big Oaks had the highest biological integrity (mean IBI reach score = 41 IBI points. The Muscatatuck NWR had a mean IBI reach score of 31 during June, which seasonally increased to a mean of 40 IBI points during summer. Watershed IBI scores and habitat condition were highest in the Big Oaks NWR.

  14. Biological Diversity, Ecological Health and Condition of Aquatic Assemblages at National Wildlife Refuges in Southern Indiana, USA

    Science.gov (United States)

    Morris, Charles C.; Robb, Joseph R.; McCoy, William

    2015-01-01

    Abstract The National Wildlife Refuge system is a vital resource for the protection and conservation of biodiversity and biological integrity in the United States. Surveys were conducted to determine the spatial and temporal patterns of fish, macroinvertebrate, and crayfish populations in two watersheds that encompass three refuges in southern Indiana. The Patoka River National Wildlife Refuge had the highest number of aquatic species with 355 macroinvertebrate taxa, six crayfish species, and 82 fish species, while the Big Oaks National Wildlife Refuge had 163 macroinvertebrate taxa, seven crayfish species, and 37 fish species. The Muscatatuck National Wildlife Refuge had the lowest diversity of macroinvertebrates with 96 taxa and six crayfish species, while possessing the second highest fish species richness with 51 species. Habitat quality was highest in the Muscatatuck River drainage with increased amounts of forested habitats compared to the Patoka River drainage. Biological integrity of the three refuges ranked the Patoka NWR as the lowest biological integrity (mean IBI reach scores = 35 IBI points), while Big Oaks had the highest biological integrity (mean IBI reach score = 41 IBI points). The Muscatatuck NWR had a mean IBI reach score of 31 during June, which seasonally increased to a mean of 40 IBI points during summer. Watershed IBI scores and habitat condition were highest in the Big Oaks NWR. PMID:25632261

  15. Amino acid metabolism of Astacus leptodactylus Esch.—III. Studies on the biosynthesis of α- and β-alanine from aspartate

    NARCIS (Netherlands)

    Marrewijk, W.J.A. van; Zandee, D.I.

    1975-01-01

    1. 1. Six hours after injection of 1- or 4-14C-aspartate into the crayfish Astacus leptodactylus almost all radioactivity incorporated was found in the amino acids. 2. 2. From both precursors only the amino acids α-alanine and glutamic acid were labelled. The biosynthesis of α-alanine from

  16. Author Details

    African Journals Online (AJOL)

    Igwe, KC. Vol 41, No 1 (2010) - Articles Socioeconomic Determinants of Income From Fresh and Processed Crayfish Marketing in Oron Local Government Area of Akwa Ibom State, Nigeria. Abstract · Vol 43 (2012) - Articles Trend Analysis of Cassava Price and Growth Rate in Nigeria Abstract. ISSN: 0300-368X.

  17. Transmission of Microsporidian Parasites of Mosquitoes.

    Science.gov (United States)

    1983-03-01

    spiders, beetle larvae, and phantom midges. 2) Feeding spores to crayfish, dragonfly larvae, damselfly larvae, water scorpions, beetles , Anopheles...use of an indirect enzyme-linked immunosorbent assay to detect baculovirus in larvae and adults of Oryctes rhinoceros from Tonga J. Gen. Virol., 47

  18. 76 FR 59835 - Endangered and Threatened Wildlife and Plants; Partial 90-Day Finding on a Petition To List 404...

    Science.gov (United States)

    2011-09-27

    ... distribution, pollution from pesticides and fertilizers, invasive species of introduced crayfish, and the... candidate species until its removal from the candidate list in 1996. In addition to the above species, 24 of... To List 404 Species in the Southeastern United States as Endangered or Threatened With Critical...

  19. CONSERVATION MANAGEMENT AND LEGISLATION THE UK EXPERIENCE

    Directory of Open Access Journals (Sweden)

    SIBLEY P. J.

    2003-04-01

    Full Text Available Underpinning the conservation management of Austropotamobius pallipes in the UK is the process of monitoring and reporting crayfish distribution. Should the current trend in the decline of A. pallipes continue, the species could be virtually extinct in mainland Britain within 30 years (SIBLEY, 2003. Conversely, if the increase in the distribution of non-indigenous crayfish species (NICS continues at its current rate, the distribution (by 10 km squares of these species could double within 15 years. These forward projections are based on a number of possibly unreliable assumptions; they illustrate however the magnitude of the challenge facing those concerned with the conservation of A. pallipes in the UK at this time. Recent work in crayfish conservation management in the UK has yielded guidance in several areas including monitoring, habitat enhancement and a re-introduction protocol for A. pallipes (KEMP and HILEY, 2003. Similarly, scientific research continues to inform our understanding of the movement and behaviour of NICS and explores new methods for the potential management of these species. In addition, the protection afforded to A. pallipes by current legislation is key to the long-term survival prospects of the species, albeit with a probable fragmented distribution, across the British Isles and continental Europe. Legal provisions in the UK derive in part from European instructions (e.g. EC Habitats and Species Directive and also from national legislation (e.g. Salmon and Freshwater Fisheries Act (1975 and the Wildlife and Countryside Act (1981. Also, a raft of “quasi-legislation” exists which requires responsible organisations in the UK to implement the white-clawed crayfish biodiversity action plan (BAP. Altogether these provisions constitute a considerable volume of legal protection for crayfish and provide the legal framework on which UK management policy and practice are based.

  20. Permanent genetic resources added to Molecular Ecology Resources Database 1 December 2010-31 January 2011.

    Science.gov (United States)

    Agata, Kiyokazu; Alasaad, Samer; Almeida-Val, Vera Maria Fonseca; Alvarez-Dios, J A; Barbisan, F; Beadell, Jon S; Beltrán, J F; Benítez, M; Bino, G; Bleay, Colin; Bloor, P; Bohlmann, Jörg; Booth, Warren; Boscari, E; Caccone, Adalgisa; Campos, Tatiana; Carvalho, B M; Climaco, Gisele Torres; Clobert, Jean; Congiu, L; Cowger, Christina; Dias, G; Doadrio, I; Farias, Izeni Pires; Ferrand, N; Freitas, Patrícia D; Fusco, G; Galetti, Pedro M; Gallardo-Escárate, Cristian; Gaunt, Michael W; Ocampo, Zaneli Gomez; Gonçalves, H; Gonzalez, E G; Haye, Pilar; Honnay, O; Hyseni, Chaz; Jacquemyn, H; Jowers, Michael J; Kakezawa, Akihiro; Kawaguchi, Eri; Keeling, Christopher I; Kwan, Ye-Seul; La Spina, Michelangelo; Lee, Wan-Ok; Leśniewska, M; Li, Yang; Liu, Haixia; Liu, Xiaolin; Lopes, S; Martínez, P; Meeus, S; Murray, Brent W; Nunes, Aline G; Okedi, Loyce M; Ouma, Johnson O; Pardo, B G; Parks, Ryan; Paula-Silva, Maria Nazaré; Pedraza-Lara, C; Perera, Omaththage P; Pino-Querido, A; Richard, Murielle; Rossini, Bruno C; Samarasekera, N Gayathri; Sánchez, Antonio; Sanchez, Juan A; Santos, Carlos Henrique Dos Anjos; Shinohara, Wataru; Soriguer, Ramón C; Sousa, Adna Cristina Barbosa; Sousa, Carolina Fernandes Da Silva; Stevens, Virginie M; Tejedo, M; Valenzuela-Bustamante, Myriam; Van de Vliet, M S; Vandepitte, K; Vera, M; Wandeler, Peter; Wang, Weimin; Won, Yong-Jin; Yamashiro, A; Yamashiro, T; Zhu, Changcheng

    2011-05-01

    This article documents the addition of 238 microsatellite marker loci to the Molecular Ecology Resources Database. Loci were developed for the following species: Alytes dickhilleni, Arapaima gigas, Austropotamobius italicus, Blumeria graminis f. sp. tritici, Cobitis lutheri, Dendroctonus ponderosae, Glossina morsitans morsitans, Haplophilus subterraneus, Kirengeshoma palmata, Lysimachia japonica, Macrolophus pygmaeus, Microtus cabrerae, Mytilus galloprovincialis, Pallisentis (Neosentis) celatus, Pulmonaria officinalis, Salminus franciscanus, Thais chocolata and Zootoca vivipara. These loci were cross-tested on the following species: Acanthina monodon, Alytes cisternasii, Alytes maurus, Alytes muletensis, Alytes obstetricans almogavarii, Alytes obstetricans boscai, Alytes obstetricans obstetricans, Alytes obstetricans pertinax, Cambarellus montezumae, Cambarellus zempoalensis, Chorus giganteus, Cobitis tetralineata, Glossina fuscipes fuscipes, Glossina pallidipes, Lysimachia japonica var. japonica, Lysimachia japonica var. minutissima, Orconectes virilis, Pacifastacus leniusculus, Procambarus clarkii, Salminus brasiliensis and Salminus hilarii. © 2011 Blackwell Publishing Ltd.

  1. REINTRODUCTION OF ASTACUS ASTACUS L. IN EAST TYROL, AUSTRIA

    Directory of Open Access Journals (Sweden)

    SINT D.

    2004-01-01

    Full Text Available In Tyrolean like in other European freshwaters, crayfish populations decreased in numbers and qualities. They are today regarded as endangered animals. The Astacus astacus (Linnaeus, 1758 population of historical evidence in Tristacher See and its out flowing stream Tristacher Seebach (mentioned already by Emperor Maximilian I in 1504 became extinct in the late 1990s. After the restoration of the stream we started a species conservation programme with various specific protection measures, including breeding and restocking of young-of-the-year and adult A. astacus. Females, after having released their young in the hatchery, were stocked together with males in a 200-m-section of Tristacher Seebach, previously populated by A. astacus. In October, the young-of-theyear crayfish were released in another area of the same stream. To show the importance of habitat diversity and shelter, four sites for introduction were selected describing a gradient of habitat diversity. We monitored general characteristics of the population (sex, size, densities and compared them to habitat conditions. Individual crayfish were tagged with gloss-paint pens to allow an observation of their movements between the different sections over the summer months. We found significant results when migration behaviour, population assemblage and habitat conditions were compared. Males frequently moved longer distances than females. Migration length corresponded to the gradient of available structures and shelter. Heterogeneous riprap was somewhat preferred to artificial shelter like bricks or plastic tubes. Sections without additional shelter showed almost no presence of crayfish. Sex and size distribution within assemblages appeared also to be affected by habitat conditions. Our results indicate the importance of monitoring in species reintroduction projects, as this research demonstrated the immediate effect and importance of habitat structure and affirmed the success of the

  2. Predicting wading bird and aquatic faunal responses to ecosystem restoration scenarios

    Science.gov (United States)

    Beerens, James M.; Trexler, Joel C.; Catano, Christopher P.

    2017-01-01

    In large-scale conservation decisions, scenario planning identifies key uncertainties of ecosystem function linked to ecological drivers affected by management, incorporates ecological feedbacks, and scales up to answer questions robust to alternative futures. Wetland restoration planning requires an understanding of how proposed changes in surface hydrology, water storage, and landscape connectivity affect aquatic animal composition, productivity, and food-web function. In the Florida Everglades, reintroduction of historical hydrologic patterns is expected to increase productivity of all trophic levels. Highly mobile indicator species such as wading birds integrate secondary productivity from aquatic prey (small fishes and crayfish) over the landscape. To evaluate how fish, crayfish, and wading birds may respond to alternative hydrologic restoration plans, we compared predicted small fish density, crayfish density and biomass, and wading bird occurrence for existing conditions to four restoration scenarios that varied water storage and removal of levees and canals (i.e. decompartmentalization). Densities of small fish and occurrence of wading birds are predicted to increase throughout most of the Everglades under all restoration options because of increased flows and connectivity. Full decompartmentalization goes furthest toward recreating hypothesized historical patterns of fish density by draining excess water ponded by levees and hydrating areas that are currently drier than in the past. In contrast, crayfish density declined and species composition shifted under all restoration options because of lengthened hydroperiods (i.e. time of inundation). Under full decompartmentalization, the distribution of increased prey available for wading birds shifted south, closer to historical locations of nesting activity in Everglades National Park.

  3. Late Pleistocene fishes of the Tennessee River Basin: an analysis of a late Pleistocene freshwater fish fauna from Bell Cave (site ACb-2) in Colbert County, Alabama, USA

    OpenAIRE

    Stephen J. Jacquemin; Jun A. Ebersole; William C. Dickinson; Charles N. Ciampaglio

    2016-01-01

    The Tennessee River Basin is considered one of the most important regions for freshwater biodiversity anywhere on the globe. The Tennessee River Basin currently includes populations of at least half of the described contemporary diversity of extant North American freshwater fishes, crayfish, mussel, and gastropod species. However, comparatively little is known about the biodiversity of this basin from the Pleistocene Epoch, particularly the late Pleistocene (?10,000 to 30,000 years B.P.) lead...

  4. Growth, yield, plant quality and nutrition of basil (Ocimum basilicum L. under soilless agricultural systems

    Directory of Open Access Journals (Sweden)

    Subhrajit Saha

    2016-12-01

    Full Text Available Traditional agricultural systems are challenged by globally declining resources resulting from climate change and growing population. Alternative agricultural practices such as aquaponics (includes crop plant and aquatic species and hydroponics (includes crop plant only have the potential to generate high yield per unit area using limited land, water, and no soil. A soilless agricultural study was conducted at the Georgia Southern University, Statesboro, GA, USA from August to November, 2015. The growth, yield, quality, and nutrition of basil (Ocimum basilicum L. cultivar Aroma 2, were compared between aquaponic and hydroponic systems using crayfish (Procambarus spp. as the aquatic species. Non-circulating floating raft systems were designed using 95 L polyethylene tanks. Equal amounts of start-up fertilizer dose were applied to both systems. The objective was to understand how the additional nutritional dynamics associated with crayfish influence the basil crop. Both fresh and dry basil plant weights were collected after harvest, followed by leaf nutrient analysis. Leaf chlorophyll content, water pH, nitrogen and temperature were measured periodically. Aquaponic basil (AqB showed 14%, 56%, and 65% more height, fresh weight, and dry weight, respectively, compared to hydroponic basil (HyB. It is logical to assume that crayfish waste (excreta and unconsumed feed has supplied the additional nutrients to AqB, resulting in greater growth and yield. The chlorophyll content (plant quality or leaf nutrients, however, did not differ between AqB and HyB. Further research is needed to investigate aquaponic crayfish yield, overall nutritional dynamics, cost-benefit ratio, and other plant characteristics under soilless systems.

  5. The Hydrodynamic Distinctiveness of Living Organisms: Communication in Complex Hydraulic Environments

    Science.gov (United States)

    Johnson, M.

    2015-12-01

    Animals make decisions about the suitability of habitat and their reaction to other organisms based on the sensory information that they first obtain. This information is transmitted, masked and filtered by fluvial processes, such as turbulent flow. Despite governing how animals interact with the environment, limited attention has been paid to the controls on the propagation of sensory signals through rivers. Some animals interpret hydraulic events and use the characteristics of wakes to sense the presence of other organisms. This implies that at least some animals can differentiate turbulent flow generated by the presence of living organisms from ambient environmental turbulence. We investigate whether there are specific flow characteristics, distinct from the ambient environment, that potentially flag the presence of organisms to other animals. ADV and PIV measurements in a series of laboratory flume experiments quantified the flow around living Signal Crayfish (Pacifastacus leniusculus) and two inanimate objects of equivalent shape and size. Experiments were repeated across a gradient of turbulence intensities generated over nine combinations of flow velocity and relative submergence. Flows downstream of living crayfish were distinct from inanimate objects, with greater turbulent intensities, higher energy in low- to intermediate frequencies, and flow structures that were less coherent in comparison to those measured downstream of inanimate objects. However, the hydrodynamic signature of crayfish became masked as the intensity of ambient turbulence exceeded that generated by living crayfish. These results demonstrate the importance of the fluvial processes in the transmission of sensory information and suggest that the ability of animals to perceive hydraulic signatures is likely to be limited in many situations in rivers. Thus, animals may need to rely on other senses, such as sight or hearing, especially where depth is shallow relative to grain size.

  6. Analysis of Three Cobble Ring Sites at Abiquiu Reservoir, Rio Arriba County, New Mexico.

    Science.gov (United States)

    1989-01-01

    included cutthroat trout, channel catfish, various suckers and chubs, and crayfish. The Rio Chama probably was too cold for most edible turtles. 9 3.0...expectations for aggregated specialized big game hunters would be use of local settings in areas of maximum diversity and abundance of edible plants...to be the first man ever to carry a line of cutlery samples west of the Mississippi River (Ferguson 1974:47). This artifact thus postdates 1840

  7. Incidence and Management Costs of Freshwater Aquatic Nuisance Species at Projects Operated by the U.S. Army Corps of Engineers

    Science.gov (United States)

    2010-07-01

    the occurrence of ANS impacts (Yes or No) from freshwater algae, large aquatic plants, fish, zebra mussels, Asiatic clams, water fleas, crayfish...2005. Freshwater aquatic nuisance species impacts and management costs and benefits at federal water resources projects. ERDC/TN ANSRP-06-3...ER D C/ EL T R- 10 -1 3 Aquatic Nuisance Species Research Program Incidence and Management Costs of Freshwater Aquatic Nuisance Species

  8. Cavitary mass lesion and recurrent pneumothoraces due to Paragonimus kellicotti infection: North American paragonimiasis.

    Science.gov (United States)

    Castilla, Elias A; Jessen, Robert; Sheck, David N; Procop, Gary W

    2003-08-01

    North American paragonimiasis is well described in omnivorous and carnivorous animals on this continent. Humans are rarely infected, largely because of dietary customs, but are at risk for infection if raw or undercooked crayfish are consumed. We describe a patient with a pleuropulmonary infection due to Paragonimus kellicotti that presented as recurrent pneumothoraces and a cavitary lesion. This is the first case of North American paragonimiasis in which the diagnosis was based on the morphology of the eggs present in histologic sections.

  9. Natural Setting and Vegetation of the Florida Panhandle. An Account of the Environments and Plant Communities of Northern Florida, West of the Suwannee River.

    Science.gov (United States)

    1986-01-01

    burrowers in the panhandle are moles, mice, shrews, cotton rats, pocket gophers, gopher turtles , crayfish, ants, and earthworms. . The detrital feeders...applicability of the terms, primeval, original, and virgin for our vegetation suddenly becomes nebulous . ., l Nonetheless there remains an obvious...mechanism for soil disturbance in wiregrass lands with the possible exception of the burrowing of gopher turtles . Anthesis occurs 5-9 months following

  10. Environmental Impact Analysis Process. Environmental Assessment Proposed SMC Military Family Housing, San Pedro, California

    Science.gov (United States)

    1998-12-01

    catches birds on the wing; eats some insects ; nests on the ground on ledges. Rallus longirostris levipes light-footed clapper rail E E Occupies and...nests in saltmarsh habitats; feeds in shallow water and on mudflats; diet comprised of small fish, crabs, crayfish, insects and some plants; nests in...occidentalis western yellow- billed cuckoo none E Likes to nest in riparian thickets of willows and cottonwoods with understory of nettles , wild grapes or

  11. The activity of glutathione S-transferase in hepatopancreas of Procambarus clarkii: seasonal variations and the influence of environmental pollutants.

    Science.gov (United States)

    Nies, E; Almar, M M; Hermenegildo, C; Monsalve, E; Romero, F J

    1991-01-01

    1. The glutathione S-transferase activity in hepatopancreas of the American red crayfish Procambarus clarkii after 15 days' acclimatization in tap water aquaria was measured in specimens collected monthly for a whole year, and shows seasonal variation. 2. Previous data on the environmental pollution of Lake Albufera suggest a possible correlation with the activity tested in the different seasons of the year considering the results of non-acclimatized animals.

  12. Marcellus and mercury: Assessing potential impacts of unconventional natural gas extraction on aquatic ecosystems in northwestern Pennsylvania.

    Science.gov (United States)

    Grant, Christopher J; Weimer, Alexander B; Marks, Nicole K; Perow, Elliott S; Oster, Jacob M; Brubaker, Kristen M; Trexler, Ryan V; Solomon, Caroline M; Lamendella, Regina

    2015-01-01

    Mercury (Hg) is a persistent element in the environment that has the ability to bioaccumulate and biomagnify up the food chain with potentially harmful effects on ecosystems and human health. Twenty-four streams remotely located in forested watersheds in northwestern PA containing naturally reproducing Salvelinus fontinalis (brook trout), were targeted to gain a better understanding of how Marcellus shale natural gas exploration may be impacting water quality, aquatic biodiversity, and Hg bioaccumulation in aquatic ecosystems. During the summer of 2012, stream water, stream bed sediments, aquatic mosses, macroinvertebrates, crayfish, brook trout, and microbial samples were collected. All streams either had experienced hydraulic fracturing (fracked, n = 14) or not yet experienced hydraulic fracturing (non-fracked, n = 10) within their watersheds at the time of sampling. Analysis of watershed characteristics (GIS) for fracked vs non-fracked sites showed no significant differences (P > 0.05), justifying comparisons between groups. Results showed significantly higher dissolved total mercury (FTHg) in stream water (P = 0.007), lower pH (P = 0.033), and higher dissolved organic matter (P = 0.001) at fracked sites. Total mercury (THg) concentrations in crayfish (P = 0.01), macroinvertebrates (P = 0.089), and predatory macroinvertebrates (P = 0.039) were observed to be higher for fracked sites. A number of positive correlations between amount of well pads within a watershed and THg in crayfish (r = 0.76, P shale natural gas exploration is having an effect on aquatic ecosystems.

  13. Risk assessment of pet-traded decapod crustaceans in the Republic of Kazakhstan, the leading country in Central Asia

    Directory of Open Access Journals (Sweden)

    Uderbayev Talgat

    2017-01-01

    Full Text Available The pet trade with decapod crustaceans has been considered one of the main pathway of introduction of these animals worldwide. As the leading markets in this regards are the Czech Republic, Germany and the USA. Central Asia is not perceived as an important market with ornamental decapod crustaceans. Despite this assumption, we found at least 16 species of freshwater shrimp, crayfish and crab species pet-traded in the Republic of Kazakhstan, the largest country in this region. Considering computed risk assessment, the origin of particular species, their availability on the market, the probability of establishment and further aspects, we identified two crayfish Procambarus clarkii and Procambarus fallax f. virginalis being the seriously hazardous taxa with high potential to threaten native crayfish species as well as inhabited ecosystems. To prevent their introductions and to minimize the risks of mentioned species, similarly as in the case of European Union, we recommend the total ban of import, trade and keeping of these high-risk taxa within Central Asia.

  14. Cherax quadricarinatus (von Martens has invaded Indonesian territory west of the Wallace Line: evidences from Java

    Directory of Open Access Journals (Sweden)

    Patoka Jiří

    2016-01-01

    Full Text Available Cherax quadricarinatus (von Martens (Decapoda: Astacidea: Parastacidae is commercially exploited and has been intentionally introduced to various tropical and subtropical countries. Once established in the wild, it frequently becomes invasive. In Indonesia, this crayfish is native only to the southern part of the Papua Province. Cherax quadricarinatus is produced in semi-intensive farms for food as well as for ornamental purposes on most of Indonesian territory. We present here the first record of this species from Java, where this crayfish has formed at least two established feral populations. In total, eight subadult and adult crayfish of both sexes were captured in two natural lakes in the city of Bogor, West Java Province. Based on climate match, we suggest that C. quadricarinatus has high potential to become established within most of Indonesian territory. As a rapidly growing species with broad tolerance to varying environmental conditions, its spread is expected and it should be viewed as a possible threat to native decapod crustaceans. Detailed monitoring is therefore needed.

  15. Identification of multiple detrital sources for Otway Supergroup sedimentary rocks: implications for basin models and chronostratigraphic correlations

    International Nuclear Information System (INIS)

    Mitchell, M.M.

    1997-01-01

    Correlation of apatite chlorine content (wt%) with apatite fission track age (Ma) from Lower Cretaceous Otway Supergroup sediments at present-day low temperatures, allows identification of two characteristic detrital source regions. Apatites from eroded Palaeozoic basement terrains yield low Cl content (generally 0.5 wt%) and syndepositional fission track ages. Where post-depositional thermal annealing ( > 70 degree C) has significantly reduced the fission track age, provenance information is preserved in the apatite Cl composition alone. In the Otway Supergroup, evidence for contemporaneous volcanism was found in both the Eumeralla Formation (Albian-Aptian), and Crayfish Group (Aptian-Berriasian) in samples located towards the central rift, where less sandy facies dominate. Results suggest that Crayfish Group sediments deposited along the northern margin of the basin were predominantly derived from eroding basement material, while the section located towards the central rift contains a greater proportion of volcanogenic detritus. Evidence from this study suggests that volcanogenic detritus was a distal sediment source throughout the entire early rift phase, prior to the main influx of arc-related volcanogenic material during deposition of the Eumeralla Formation. As diagenesis of volcanogenic sediments significantly reduces porosity and permeability of the sandstones, reservoir quality and petroleum potential may be significantly reduced in the Crayfish Group in deeper parts of the basin where a greater proportion of volcanogenic detritus is suggested. The results presented here provide important information regarding Lower Cretaceous Otway Basin stratigraphy and clearly indicate that this methodology may have wider application. (authors)

  16. A possible role for the immune system in adult neurogenesis: new insights from an invertebrate model.

    Science.gov (United States)

    Harzsch, Steffen; von Bohlen Und Halbach, Oliver

    2016-04-01

    Persistent neurogenesis in the adult brain of both vertebrates and invertebrates was previously considered to be driven by self-renewing neuronal stem cells of ectodermal origin. Recent findings in an invertebrate model challenge this view and instead provide evidence for a recruitment of neuronal precursors from a non-neuronal source. In the brain of adult crayfish, a neurogenic niche was identified that contributes progeny to the adult central olfactory pathway. The niche may function in attracting cells from the hemolymph and transforming them into cells with a neuronal fate. This finding implies that the first-generation neuronal precursors located in the crayfish neurogenic niche are not self-renewing. Evidence is summarized in support of a critical re-evaluation of long-term self-renewal of mammalian neuronal stem cells. Latest findings suggest that a tight link between the immune system and the system driving adult neurogenesis may not only exist in the crayfish but also in mammals. Copyright © 2015 Elsevier GmbH. All rights reserved.

  17. Geochemical pathways and biological uptake of radium in small Canadian Shield lakes

    International Nuclear Information System (INIS)

    Hesslein, R.H.; Slavicek, E.

    1984-01-01

    The sediment-water interactions and biological uptake of 226 Ra are described for four small Canadian Shield lakes at the Experimental Lakes Area, Kenora, Ontario. A single addition of 226 Ra was made to each lake between 1970 and 1976. Approximately 90 percent of the added 226 Ra initially sorbed to the sediments. Outflow from the lakes showed losses of only 5-11 percent 226 Ra per year. Models are proposed for adsorption and outflow of 226 Ra from lakes. Biological uptake and long-term 226 Ra concentrations were measured in three species of macrophytes, crayfish, and five species of fish. Bioaccumulation ranged from 1100 to 5000 in macrophytes, 705 in crayfish, from 30 to 80 in large trout (Salvelinus namaycush), white sucker (Catostomus commersoni), and lake whitefish (Coregonus clupeaformis), and from 230 to 1200 in fathead minnows (Pimephales promelas), pearl dace (Semotilus margarita), and northern redbelly dace (Chrosomus eos). The concept of Ra/Ca ratio in organisms versus water and food is used to explain the differences in bioaccumulation. 226 Ra is discriminated against versus calcium by fish but favoured by macrophytes and crayfish

  18. How do animals communicate in complex hydrodynamic environments? Linking hydraulics and ecology in rivers.

    Science.gov (United States)

    Johnson, Matthew; Rice, Stephen

    2015-04-01

    Animals make decisions about the suitability of habitat and their reaction to other organisms based on the sensory information that they first obtain from the environment and other organisms within that environment. Sensory information, such as sounds, scents, vibrations and visual cues, is transported, transmitted, masked and filtered by fluvial processes, such as turbulent flow. Despite the fundamental importance of this information in dictating how animals interact with the environment, only limited attention has been paid to the environmental controls on the propagation of sensory signals and cues through fluvial systems. Aquatic animals use and respond to hydraulic characteristics when navigating their environment and selecting habitat. There is evidence that some animals can also sense the presence of other organisms from the hydraulic characteristics of their wake. This implies that at least some aquatic animals can differentiate between the turbulent flow generated by the presence of living organisms and ambient turbulence generated by the environment. We investigate whether there are specific flow characteristics, distinct from the ambient environment, that potentially flag the presence of organisms to other animals. Acoustic Doppler and Particle Image Velocimetry measurements in a series of laboratory flume experiments quantified the flow around living Signal Crayfish (Pacifastacus leniusculus) and two inanimate objects of equivalent shape and size. Experiments were repeated across a gradient of turbulence intensities generated over nine combinations of flow velocity and relative submergence. Flows downstream of living crayfish were distinct from inanimate objects, with greater turbulent intensities, higher energy in low- to intermediate frequencies, and flow structures that were less coherent in comparison to those measured downstream of inanimate objects. However, the hydrodynamic signature of crayfish became masked as the intensity of ambient

  19. Kovada Gölü'nde Yaşayan İstakozlarda (Astacus leptodactylus Bazı Ağır Metallerin Birikiminin İncelenmesi

    Directory of Open Access Journals (Sweden)

    İsmail Kır

    2010-11-01

    Full Text Available 05.04.2005-23.02.2006 tarihleri arasında yapılan bu çalışmada; Kovada Gölü'nde yaşayan istakoz (Astacus leptodactylus'ların kas, karaciğer ve karapaks dokularında bazı ağır metal birikiminin incelenmesi amaçlanmıştır. Çalışmada; 32 adet tatlısu istakozu gölü'ün değişik bölgelerinden mevsimlik periyotlarla yakalanarak incelenmiştir. Örneklerin ağır metal analizi ICP-OES cihazı ile yapılmıştır. Tatlısu istakozunda yapılan ağır metal analizleri sonucunda doku ve organlarda Cu, Mn, Zn, Al, Ni, Cd, Pb, Cr ve Fe tespit edilmiştir. Doku ve organlarda en fazla biriken metalin Al olduğu belirlenmiştir. Metallerin, karaciğer ve karapaksta kas dokusuna göre daha fazla biriktiği saptanmıştır. Anahtar kelimeler: Ağır Metal, Kovada Gölü, Su Kirliliği, Tatlısu istakozu The Investigation of some Heavy Metals in Crayfish (Astacus leptodactylus Inhabiting Kovada Lake This study was carried out between 05.04.2005 - 23.02.2006 and was aimed to investigate accumulation of some heavy metals in muscle, liver and carapace tissues of crayfish (Astacus leptodactylus inhabiting Kovada Lake. In this study, totally 32 crayfish were caught from different regions of Kovada Lake seasonally and investigated. The heavy metal analysis of samples were carried out by using ICP-OES. According to the results of the analysis of heavy metals were determined Cu, Mn, Zn, Al, Ni, Cd, Pb, Cr and Fe in tissues and organs of crayfish. It was determined that Al was the highest metal in tissues and organs. The highest metal concentrations were found in the liver and carapace than muscle. Key words: Heavy Metal, Kovada Lake, Water Pollution, Crayfish

  20. Melanization and Pathogenicity in the Insect, Tenebrio molitor, and the Crustacean, Pacifastacus leniusculus, by Aeromonas hydrophila AH-3

    Science.gov (United States)

    Noonin, Chadanat; Jiravanichpaisal, Pikul; Söderhäll, Irene; Merino, Susana; Tomás, Juan M.; Söderhäll, Kenneth

    2010-01-01

    Aeromonas hydrophila is the most common Aeromonas species causing infections in human and other animals such as amphibians, reptiles, fish and crustaceans. Pathogenesis of Aeromonas species have been reported to be associated with virulence factors such as lipopolysaccharides (LPS), bacterial toxins, bacterial secretion systems, flagella, and other surface molecules. Several mutant strains of A. hydrophila AH-3 were initially used to study their virulence in two animal species, Pacifastacus leniusculus (crayfish) and Tenebrio molitor larvae (mealworm). The AH-3 strains used in this study have mutations in genes involving the synthesis of flagella, LPS structures, secretion systems, and some other factors, which have been reported to be involved in A. hydrophila pathogenicity. Our study shows that the LPS (O-antigen and external core) is the most determinant A. hydrophila AH-3 virulence factor in both animals. Furthermore, we studied the immune responses of these hosts to infection of virulent or non-virulent strains of A. hydrophila AH-3. The AH-3 wild type (WT) containing the complete LPS core is highly virulent and this bacterium strongly stimulated the prophenoloxidase activating system resulting in melanization in both crayfish and mealworm. In contrast, the ΔwaaE mutant which has LPS without O-antigen and external core was non-virulent and lost ability to stimulate this system and melanization in these two animals. The high phenoloxidase activity found in WT infected crayfish appears to result from a low expression of pacifastin, a prophenoloxidase activating enzyme inhibitor, and this gene expression was not changed in the ΔwaaE mutant infected animal and consequently phenoloxidase activity was not altered as compared to non-infected animals. Therefore we show that the virulence factors of A. hydrophila are the same regardless whether an insect or a crustacean is infected and the O-antigen and external core is essential for activation of the proPO system

  1. Distribution of cobalt 60 in a mollusc, a crustacean and a freshwater teleost: variations as a function of the source of pollution and during elimination

    International Nuclear Information System (INIS)

    Amiard, J.C.; Amiard-Triquet, C.

    1979-01-01

    57 Co, 58 Co and 60 Co are present in nuclear test debris as well as in effluents of the non-military nuclear industry. The stable isotope, which is a constituent of vitamin B 12 , has very important biological functions. For each species, three experiments were carried out: (1) starved animals were immersed in 60 Co-contaminated water; (2) animals were immersed in contaminated water and received radioactive food and (3) animals were placed in fresh water without any pollutant but received contaminated food. Radiation doses were calculated for contamination via both food and water. When 60 Co is taken up directly from water, the most contaminated organs are external ones, especially the shell of the snail Lymnaea palustris and the exoskeleton and feeding appendages of the crayfish Astacus leptodactylus. Contamination via food is responsible for a relatively greater accumulation of radiocobalt in internal organs. The cobalt content of muscles - that is to say the edible parts of crayfish and common carp Cyprinus carpio -is very low. The highest concentrations recorded are in the visceral mass of the snail, the digestive gland of the crayfish and the kidneys of the carp. Internal doses for these organs are considerably higher than those for entire animals. Therefore, as a result of 60 Co distribution, they are critical organs for the freshwater species. Except for the carp, external radiation is very weak compared with internal radiation. A strong retention of 60 Co is observed for the shell of L. palustris while the desorption of radiocobalt from the exoskeleton of A. leptodactylus is easier. In carp, the 60 Co taken up by the gut from food, as well as from water, is rapidly eliminated. (author)

  2. Mechanism to preserve phrenic nerve function during photosensitization reaction: drug uptake and photosensitization reaction effect on electric propagation

    Science.gov (United States)

    Takahashi, Haruka; Hamada, Risa; Ogawa, Emiyu; Arai, Tsunenori

    2018-02-01

    To study a mechanism of phrenic nerve preservation phenomena during a photosensitization reaction, we investigated an uptake of talaporfin sodium and photosensitization reaction effect on an electric propagation. Right phrenic nerve was completely preserved after superior vena cava isolations using the photosensitization reaction in canine animal experiments, in spite of adjacent myocardium was electrically blocked. We predicted that low drug uptake and/or low photosensitization reaction effect on the nerve might be a mechanism of that phenomena. To investigate uptake to various nerve tissue, a healthy extracted crayfish ventral nerve cord and an extracted porcine phrenic nerve were immersed in 20 μg/ml talaporfin sodium solution for 0-240 min. The mean talaporfin sodium fluorescence brightness increased depending on the immersion time. This brightness saturated around the immersion time of 120 min. We found that talaporfin sodium uptake inside the perineurium which directly related to the electric propagation function was lower than that of outside in the porcine phrenic nerve. To investigate photosensitization reaction effect on electric propagation, the crayfish nerve was immersed into the same solution for 15 min and irradiated by a 663 nm laser light with 120 mW/cm2. Since we found the action potential disappeared when the irradiation time was 25-65 s, we consider that the crayfish nerve does not tolerant to the photosensitization reaction on electric propagation function at atmospheric pressure. From these results, we think that the low uptake of talaporfin sodium inside the perineurium and low oxygen partial pressure of nerve might be the possible mechanism to preserve phrenic nerve in vivo.

  3. Systematics and position of Nephrops among the lobsters.

    Science.gov (United States)

    Tshudy, Dale

    2013-01-01

    This chapter presents and explains the position of Nephrops norvegicus in the classification of lobsters. Covered, in order, are systematic classification of Nephrops, taxonomic history of Nephrops, and analysis of Nephrops in nephropid phylogeny. The genus Nephrops was erected by Leach in 1814 and has a long and interesting taxonomic history. Prior to 1972, Nephrops was known by 14 Recent species. All but one of these, N. norvegicus, were removed to a new genus, Metanephrops, by Jenkins (1972). Today, N. norvegicus is still the only known living representative of the genus. Similarly, Nephrops is known by only one fossil species, the Miocene Nephrops kvistgaardae, although several other fossil species have been previously referred to this genus. Nephrops, along with the other familiar and commercially important marine clawed lobsters, is referred to Family Nephropidae, one of 17 marine clawed lobster families arrayed in 3 infraorders, 6 families each in the Astacidea and Glypheidea and 5 in the Polychelida. Infraorder Astacidea includes the Superfamily Nephropoidea, as well as the lesser known 'reef lobsters' of the Superfamily Enoplometopoidea, and the freshwater crayfish, Superfamily Astacoidea. In phylogenetic analyses, the freshwater crayfish form a sister group to the Nephropoidea. It is interpreted that freshwater crayfish evolved from nephropoid lobsters, but from which lobster group is uncertain. The taxonomic placement of N. norvegicus is stable at all levels, from species on up. Despite that, the phylogenetic relationships of Nephrops to other nephropid genera are unsettled due to conflicting results in morphological and molecular analyses. Currently, new morphological characters and new genes are being analysed in the hope of elucidating nephropid phylogeny. Copyright © 2013 Elsevier Ltd. All rights reserved.

  4. Fixation and long-term accumulation of tritium from tritiated water in an experimental aquatic environment

    International Nuclear Information System (INIS)

    Strand, J.A.; Templeton, W.L.; Olson, P.A.

    1975-01-01

    The accumulation of tritium in selected freshwater biota was studied in a 10 m diameter concrete-lined pond at the Hanford Atomic Energy Works. Tritium as tritiated water was introduced for 8 months continuously in the replacement water at a concentration of μCi per liter; and water, biota (carp, clams, crayfish, periphyton, pondweed), and sediments were sampled on a predetermined schedule. The pond was maintained on uncontaminated replacement waters for an additional 8 months to determine the rate of elimination from the ecosystem. After the first day, tissue-free-water tritium in all biota approached an equilibrium with pond water. Final concentration factors of 0.89, 0.87, 0.82, 0.92, 0.77, 0.88 were calculated for carp, clam, crayfish, snail, periphyton, and pondweed. Although highly variable, analyses of pond sediments suggested an initial rapid uptake by the loose water fraction, attaining 0.30 of the pond equilibrium level in three days. There was evidence to suggest a secondary slower rate of uptake that accounted for 0.65 of the pond equilibrium level as determined at seven months. Tissue-bond tritium initially increased rapidly in all biota sampled, but slowed with time. Equilibrium conditions were not reached. Final concentration factors for carp, clam, crayfish, snail, periphyton, and pondweed were calculated to be 0.49, 0.10, 0.53, 0.54, 0.15, and 0.62. Analyses of sediments after removal of the loose water fraction revealed little or no organically bound tritium

  5. Melanization and pathogenicity in the insect, Tenebrio molitor, and the crustacean, Pacifastacus leniusculus, by Aeromonas hydrophila AH-3.

    Directory of Open Access Journals (Sweden)

    Chadanat Noonin

    Full Text Available Aeromonas hydrophila is the most common Aeromonas species causing infections in human and other animals such as amphibians, reptiles, fish and crustaceans. Pathogenesis of Aeromonas species have been reported to be associated with virulence factors such as lipopolysaccharides (LPS, bacterial toxins, bacterial secretion systems, flagella, and other surface molecules. Several mutant strains of A. hydrophila AH-3 were initially used to study their virulence in two animal species, Pacifastacus leniusculus (crayfish and Tenebrio molitor larvae (mealworm. The AH-3 strains used in this study have mutations in genes involving the synthesis of flagella, LPS structures, secretion systems, and some other factors, which have been reported to be involved in A. hydrophila pathogenicity. Our study shows that the LPS (O-antigen and external core is the most determinant A. hydrophila AH-3 virulence factor in both animals. Furthermore, we studied the immune responses of these hosts to infection of virulent or non-virulent strains of A. hydrophila AH-3. The AH-3 wild type (WT containing the complete LPS core is highly virulent and this bacterium strongly stimulated the prophenoloxidase activating system resulting in melanization in both crayfish and mealworm. In contrast, the ΔwaaE mutant which has LPS without O-antigen and external core was non-virulent and lost ability to stimulate this system and melanization in these two animals. The high phenoloxidase activity found in WT infected crayfish appears to result from a low expression of pacifastin, a prophenoloxidase activating enzyme inhibitor, and this gene expression was not changed in the ΔwaaE mutant infected animal and consequently phenoloxidase activity was not altered as compared to non-infected animals. Therefore we show that the virulence factors of A. hydrophila are the same regardless whether an insect or a crustacean is infected and the O-antigen and external core is essential for activation of the

  6. Sensory input from the osphradium modulates the response to memory-enhancing stressors in Lymnaea stagnalis.

    Science.gov (United States)

    Karnik, Vikram; Braun, Marvin; Dalesman, Sarah; Lukowiak, Ken

    2012-02-01

    In the freshwater environment species often rely on chemosensory information to modulate behavior. The pond snail, Lymnaea stagnalis, is a model species used to characterize the causal mechanisms of long-term memory (LTM) formation. Chemical stressors including crayfish kairomones and KCl enhance LTM formation (≥24 h) in Lymnaea; however, how these stressors are sensed and the mechanism by which they affect the electrophysiological properties of neurons necessary for memory formation are poorly understood. Here, we assessed whether the osphradium, a primary chemosensory organ in Lymnaea, modulates LTM enhancement. To test this we severed the osphradial nerve proximal to the osphradium, using sham-operated animals as controls, and assessed the behavioral and electrophysiological response to crayfish kairomones and KCl. We operantly conditioned aerial respiratory behavior in intact, sham and osphradially cut animals, and tested for enhanced memory formation after exposure to the chemical stressors. Sham-operated animals displayed the same memory enhancement as intact animals but snails with a severed osphradial nerve did not show LTM enhancement. Extracellular recordings made from the osphradial nerve demonstrate that these stressors evoked afferent sensory activity. Intracellular recordings from right pedal dorsal 1 (RPeD1), a neuron necessary for LTM formation, demonstrate that its electrophysiological activity is altered by input from the osphradium following exposure to crayfish kairomones or KCl in sham and intact animals but no response is seen in RPeD1 in osphradially cut animals. Therefore, sensory input from the osphradium is necessary for LTM enhancement following exposure to these chemical stressors.

  7. Use of electroreception during foraging by the Australian lungfish.

    Science.gov (United States)

    Watt; Evans; Joss

    1999-11-01

    A diverse range of animals, including elasmobranchs and nonteleost fish, use passive electroreception to locate hidden prey. The Australian lungfish, Neoceratodus forsteri (Krefft 1870), has ampullary organs analogous in form to the electroreceptors of other nonteleost fish. Afferents from these ampullae project to regions in the brain that are known to process electrosensory information in other species, suggesting that N. forsteri possesses an electric sense that may be used during prey location. To explore this hypothesis directly, we first characterized food-locating behaviour in N. forsteri and then conducted an experiment designed to quantify the effects of manipulating electrical and olfactory stimuli from live prey. A small crayfish, Cherax destructor, was housed in a specially constructed chamber hidden beneath the substrate, which prevented emission of chemical, mechanical and visual cues, but allowed transmission of bioelectric fields. Control treatments included presentation of electrically shielded prey, a dead crayfish and an empty chamber. In some treatments, a competing olfactory signal was presented simultaneously at the other end of the test tank to assess the relative salience of this sensory modality. The lungfish responded to the crayfish in the unshielded chamber with accurate and sustained feeding movements, even with a competing olfactory signal. By contrast, the abolition of electrical cues in the three control treatments reduced the accuracy and frequency of feeding movements in the vicinity of the target chamber. These results show that N. forsteri is capable of perceiving the weak electric fields surrounding living animals, and suggest that it uses this information when foraging to locate prey hidden from view. Copyright 1999 The Association for the Study of Animal Behaviour.

  8. Tritium behaviour in aquatic plants and animals in a freshwater marsh ecosystem

    International Nuclear Information System (INIS)

    Adams, L.W.; Peterle, T.J.; White, G.C.

    1979-01-01

    Ten curies of tritium as tritiated water (HTO) were experimentally added to an enclosed 2-ha Lake Erie marsh on 20 October 1973. Tritium kinetics in selected plants and animals were determined over a one-year period. Tritium levels in the marsh bottom sediment averaged 1.8 times the marsh water levels, with little evidence of tritium concentration above the marsh water tritium levels in the flora and fauna. The unbound tritium: marsh water tritium ratios in smartweed (Polygonum lapathifolium) and pickerelweed (Pontederia cordata) (both emergents) were lower than the same ratio for pondweed (Potamogeton crispus) (a submergent). There was some evidence of bound tritium buildup in midsummer, particularly in the pondweed. Tritium uptake into the unbound compartments of crayfish (Procambarus blandingi), carp (Cyprinus carpio) and bluegills (Lepomis macrochirus) was rapid. For crayfish, maximum HTO levels were observed on days 2 and 3 following treatment for muscle and viscera respectively. Unbound HTO in carp muscle peaked in 4 hours and the level in carp viscera reached a maximum in 2 days, in bluegill muscle and viscera on day 1. Unbound HTO in all species decreased following peak levels, paralleling marsh water HTO activity. Tritium uptake into the bound compartments was not as rapid nor were the levels as high as for unbound HTO in the fauna. The peak bound level in crayfish muscle was observed on day 10 (bound : unbound ratio of 0.34) and the maximum level in viscera was noted on day 20 (bound : unbound ratio of 0.23). Bound tritium in carp muscle and viscera reached maximum levels on day 20 (bound : unbound ratios of 0.25 and 0.39 respectively). In bluegills, peaks were reached on days 5 and 7 (bound : unbound ratios of 0.35 and 0.38 for muscle and viscera respectively). Bound tritium in all species decreased following maximum levels

  9. Effects of sublethal exposure to lead on levels of energetic compounds in Procambarus clarkii (Girard, 1852)

    Energy Technology Data Exchange (ETDEWEB)

    Martinez, M.; Torreblanca, A.; Del Ramo, J.; Diaz-Mayans, J. (Univ. of Valencia (Spain))

    1994-05-01

    Lead is neither essential nor beneficial to living organisms; all existing data show that its metabolic effects are adverse. Lead is toxic to all phyla of aquatic biota. Most of the lead discharged into surface water is rapidly incorporated into suspended and bottom sediments. The American red crayfish, Procambarus clarkii, lives in a wide range of environmental conditions that include highly polluted waters. Lead present in take sediments can be available to aquatic animals such as P. clarkii because it is a detritivor and burrow into the sediment. In fact, we found remarkable levels of lead in tissues of P. clarkii caught in Albufera Lake and kept 15 days in clean water (e. g. 223 [mu]g/g dry weight in gills). Furthermore, P. clarkii has a high capacity for lead accumulation from water, and gills were the most important tissue of lead accumulation. Among effects that contaminants have on the physiology of the organisms, energetic state variables are important, since they will alter both survival and reproduction. Hepatopancreas is a major site for the energetic reserve in crayfish and is a site of lead accumulation, although metal concentration in this organ is not as high as gills. The purpose of this study was to examine changes in energy reserves in hepatopancreas and gills of the crayfish P. clarkii, in response to sublethal exposure to lead. Gills are directly exposed to contaminants in the environment, and they are the first organ showing alterations by the action of the contaminants. Hepatopancreas was also chosen due to both, its relevance in the energetic metabolism and its role in heavy metal detoxification mechanisms.

  10. Herbivore preference for native vs. exotic plants: generalist herbivores from multiple continents prefer exotic plants that are evolutionarily naïve.

    Directory of Open Access Journals (Sweden)

    Wendy E Morrison

    2011-03-01

    Full Text Available Enemy release and biotic resistance are competing, but not mutually exclusive, hypotheses addressing the success or failure of non-native plants entering a new region. Enemy release predicts that exotic plants become invasive by escaping their co-adapted herbivores and by being unrecognized or unpalatable to native herbivores that have not been selected to consume them. In contrast, biotic resistance predicts that native generalist herbivores will suppress exotic plants that will not have been selected to deter these herbivores. We tested these hypotheses using five generalist herbivores from North or South America and nine confamilial pairs of native and exotic aquatic plants. Four of five herbivores showed 2.4-17.3 fold preferences for exotic over native plants. Three species of South American apple snails (Pomacea sp. preferred North American over South American macrophytes, while a North American crayfish Procambarus spiculifer preferred South American, Asian, and Australian macrophytes over North American relatives. Apple snails have their center of diversity in South America, but a single species (Pomacea paludosa occurs in North America. This species, with a South American lineage but a North American distribution, did not differentiate between South American and North American plants. Its preferences correlated with preferences of its South American relatives rather than with preferences of the North American crayfish, consistent with evolutionary inertia due to its South American lineage. Tests of plant traits indicated that the crayfish responded primarily to plant structure, the apple snails primarily to plant chemistry, and that plant protein concentration played no detectable role. Generalist herbivores preferred non-native plants, suggesting that intact guilds of native, generalist herbivores may provide biotic resistance to plant invasions. Past invasions may have been facilitated by removal of native herbivores, introduction of

  11. Physical data and biological data for algae, aquatic invertebrates, and fish from selected reaches on the Carson and Truckee rivers, Nevada and California, 1993-97

    Science.gov (United States)

    Lawrence, S.J.; Seiler, R.L.

    2002-01-01

    This report, a product of the National Water- Quality Assessment Program, is a compilation of physical data and biological data for algae, aquatic invertebrates, and fish collected in the Carson and Truckee River Basins, Nevada and California. Most of the data were collected between 1993 and 1996 at selected reaches on the Carson and Truckee Rivers. Algae and aquatic invertebrate samples were collected from cobble riffles, submerged woody-snag habitats, and from depositional areas such as pools. Between 1993 and 1996, fish and crayfish were collected from all wadeable habitats at each of seven basic-fixed sites using either electroshocking methods or seining. Additional fish and crayfish were collected at one site on the Truckee River in 1997. Fish were identified to species, measured for total and standard length, checked for anomalies, and weighed at the collection site. Fish were returned to the stream after measurements were taken. Measurements of water depth, stream velocity, determinations of substrate type and substrate embeddedness were made at each sampling site. Algae and aquatic invertebrate samples were sent to the U.S. Geological Survey National Water-Quality Laboratory for identification and enumeration. A total of 103 semi-quantitative and 55 qualitative algae samples were collected at 20 river reaches on the Carson and Truckee Rivers between 1993 and 1996. These samples represent algae in cobble riffles, on submerged woody snags, and on sediment surfaces in depositional areas. In those 158 samples, 514 algal species, varieties, or forms were identified. Of the 8 algal phyla represented, the diatoms (Phylum Bacillariophyta) were the most abundant with 351 species, varieties, or forms. The green algae (Phylum Chlorophyta) were next in abundance with 108 species, varieties, or forms followed by the blue-green algae (Phylum Cyanophyta) with 41 species, varieties, or forms. A total of 49 semi-quantitative aquatic invertebrate samples were collected at 27

  12. Uranium concentration by Crustacea: a structural, ultrastructural and microanalytical study by secondary ion emission and electron probe X ray microanalysis

    International Nuclear Information System (INIS)

    Chassard-Bouchaud, Colette

    1982-01-01

    Experimental intoxications were performed on the Crayfish Pontastacus leptodactylus using hydrosoluble uranium nitrate. Investigations demonstrate that Crustacea are able to concentrate both uranium main radioactive isotopes 238 U and 235 U within the cuticle, gill epithelium, midgut gland (=hepatopancreas) and macrophagic hemocytes. The storage occurs within nucleus and lysosomal system where uranium is precipitated in the form of an unsoluble phosphate. The proposed hypothesis for the metal extrusion is the following: residual bodies containing the uranium precipitates are extruded into the extracellular space where they are absorbed by phagocytosis, by the macrophagic hemocytes [fr

  13. 40 CFR 180.274 - Propanil; tolerances for residues.

    Science.gov (United States)

    2010-07-01

    ... Cattle, meat 0.05 Cattle, meat byproducts 1.0 Crayfish 0.05 Egg 0.30 Goat, fat 0.10 Goat, meat 0.05 Goat, meat byproducts 1.0 Hog, fat 0.10 Hog, meat 0.05 Hog, meat byproducts 1.0 Horse, fat 0.10 Horse, meat 0.05 Horse, meat byproducts 1.0 Milk 0.05 Poultry, fat 0.05 Poultry, meat 0.10 Poultry, meat byproducts...

  14. Circulation of copper in the biotic compartments of a freshwater dammed reservoir

    Energy Technology Data Exchange (ETDEWEB)

    Vinot, I.; Pihan, J.C

    2005-01-01

    This study concerns a chronic copper release in an aquatic ecosystem: Mirgenbach reservoir; which is characterized by high salinity, conductivity and hardness, a eutrophic state and a high temperature. To study the bioavailability of copper in the biotic compartments, the sampling covered the entire food chain (phyto- and zooplankton, macroalgae, aquatic plants, crustaceans, mollusks, and fish). Of the organisms present, the filter feeder Dreissena polymorpha, the detritivorous Bithynia tentaculata and Orconectes limosus were most contaminated by copper. The level of copper found in fish was the lowest. Body copper concentrations recorded in the present study show large variability between species even in some that are closely related. In most cases, however, the metal handling strategy, feeding habits, morphology and ecology can, at least partially, explain the metal content recorded. Pollution factors have been used to assess the state of contamination of the food chain. This study showed finally that the copper in the lake is bioavailable and bioaccumulated by organisms up to high levels and some effects of long-term toxicity of copper on benthic community and planktonic biomass were pointed out.

  15. Circulation of copper in the biotic compartments of a freshwater dammed reservoir

    International Nuclear Information System (INIS)

    Vinot, I.; Pihan, J.C.

    2005-01-01

    This study concerns a chronic copper release in an aquatic ecosystem: Mirgenbach reservoir; which is characterized by high salinity, conductivity and hardness, a eutrophic state and a high temperature. To study the bioavailability of copper in the biotic compartments, the sampling covered the entire food chain (phyto- and zooplankton, macroalgae, aquatic plants, crustaceans, mollusks, and fish). Of the organisms present, the filter feeder Dreissena polymorpha, the detritivorous Bithynia tentaculata and Orconectes limosus were most contaminated by copper. The level of copper found in fish was the lowest. Body copper concentrations recorded in the present study show large variability between species even in some that are closely related. In most cases, however, the metal handling strategy, feeding habits, morphology and ecology can, at least partially, explain the metal content recorded. Pollution factors have been used to assess the state of contamination of the food chain. This study showed finally that the copper in the lake is bioavailable and bioaccumulated by organisms up to high levels and some effects of long-term toxicity of copper on benthic community and planktonic biomass were pointed out

  16. Circulation of copper in the biotic compartments of a freshwater dammed reservoir.

    Science.gov (United States)

    Vinot, I; Pihan, J C

    2005-01-01

    This study concerns a chronic copper release in an aquatic ecosystem: Mirgenbach reservoir; which is characterized by high salinity, conductivity and hardness, a eutrophic state and a high temperature. To study the bioavailability of copper in the biotic compartments, the sampling covered the entire food chain (phyto- and zooplankton, macroalgae, aquatic plants, crustaceans, mollusks, and fish). Of the organisms present, the filter feeder Dreissena polymorpha, the detritivorous Bithynia tentaculata and Orconectes limosus were most contaminated by copper. The level of copper found in fish was the lowest. Body copper concentrations recorded in the present study show large variability between species even in some that are closely related. In most cases, however, the metal handling strategy, feeding habits, morphology and ecology can, at least partially, explain the metal content recorded. Pollution factors have been used to assess the state of contamination of the food chain. This study showed finally that the copper in the lake is bioavailable and bioaccumulated by organisms up to high levels and some effects of long-term toxicity of copper on benthic community and planktonic biomass were pointed out.

  17. Development of Ecogeomorphological (EGM Stream Design and Assessment Tools for the Piedmont of Alabama, USA

    Directory of Open Access Journals (Sweden)

    Brian Helms

    2016-04-01

    Full Text Available Regional data needed for effective stream restoration include hydraulic geometry relationships (i.e., regional curves and reference channel morphology parameters. Increasingly ecological conditions are being considered when designing, implementing, and assessing restoration efforts. We provide morphology relationships and associated ecological endpoint curves for reference streams in the Alabama piedmont. Twenty-one reference stream reaches were identified in the Tallapoosa drainage of Alabama, ranging from 0.2 to 242 km2 drainage area. Geomorphic surveys were conducted in each stream to measure riffle cross-sections and longitudinal profiles and related to drainage area to develop regional curves. Fish, crayfish, and benthic macroinvertebrates were collected from each surveyed reach and related to drainage area and geomorphic data to provide associated biological community endpoints. Bankfull channel cross-section area, width, mean depth, and estimated discharge were strongly correlated to watershed drainage area, similar to efforts in other areas of the Piedmont ecoregion. Multiple measures of fish assemblages and crayfish size were strongly predicted by drainage area and geomorphic dimensions. Macroinvertebrates showed no taxonomic and limited functional relationships with drainage area and geomorphic dimension. These tools, which integrate geomorphological and ecological conditions, can result in improved stream evaluations and designs increasing the effectiveness of stream restoration projects.

  18. Potential use of power plant reject heat in commercial aquaculture

    Energy Technology Data Exchange (ETDEWEB)

    Olszewski, M.

    1977-01-01

    Current research and commercial activities in aquaculture operations have been reviewed. An aquaculture system using mostly herbivorous species in pond culture is proposed as a means of using waste heat to produce reasonably priced protein. The system uses waste water streams, such as secondary sewage effluent, animal wastes, or some industrial waste streams as a primary nutrient source to grow algae, which is fed to fish and clams. Crayfish feed on the clam wastes thereby providing a clean effluent from the aquaculture system. Alternate fish associations are presented and it appears that a carp or tilapia association is desirable. An aquaculture system capable of rejecting all the waste heat from a 1000-MW(e) power station in winter can accommodate about half the summer heat rejection load. The aquaculture facility would require approximately 133 ha and would produce 4.1 x 10/sup 5/ kg/year of fish, 1.5 x 10/sup 6/ kg/year of clam meat, and 1.5 x 10/sup 4/ kg/year of live crayfish. The estimated annual pretax profit from this operation is one million dollars. Several possible problem areas have been identified. However, technical solutions appear to be readily available to solve these problems. The proposed system shows considerable economic promise. Small scale experiments have demonstrated the technical feasibility of various components of the system. It therefore appears that a pilot scale experimental facility should be operated.

  19. Adult neurogenesis in the central olfactory pathway of dendrobranchiate and caridean shrimps: New insights into the evolution of the deutocerebral proliferative system in reptant decapods.

    Science.gov (United States)

    Wittfoth, Christin; Harzsch, Steffen

    2018-04-16

    Persistent neurogenesis in the central olfactory pathway characterizes many reptant decapods such as lobsters, crayfish and crabs. In these animals, the deutocerebral proliferative system generates new neurons which integrate into the neuronal network of the first order processing neuropil of the olfactory system, the deutocerebral chemosensory lobes (also called olfactory lobes). However, differences concerning the phenotype and the mechanisms that drive adult neurogenesis were reported in crayfish versus spiny lobsters. While numerous studies have focussed on these mechanisms and regulation of adult neurogenesis, investigations about the phylogenetic distribution are missing. To contribute an evolutionary perspective on adult neurogenesis in decapods, we investigated two representatives of basally diverging lineages, the dendrobranchiate Penaeus vannamei and the caridean Crangon crangon using the thymidine analogue Bromodeoxyuridine (BrdU) as marker for the S phase of cycling cells. Compared to reptant decapods, our results suggest a simpler mechanism of neurogenesis in the adult brain of dendrobranchiate and caridean shrimps. Observed differences in the rate of proliferation and spatial dimensions are suggested to correlate with the complexity of the olfactory system. We assume that a more complex and mitotically more active proliferative system in reptant decapods evolved with the emergence of another processing neuropil, the accessory lobes. This article is protected by copyright. All rights reserved. © 2018 Wiley Periodicals, Inc.

  20. Spatial and temporal variations of mercury levels in Okefenokee invertebrates: Southeast Georgia

    International Nuclear Information System (INIS)

    George, Bagie M.; Batzer, Darold

    2008-01-01

    Accumulation of mercury in wetland ecosystems has raised concerns about impacts on wetland food webs. This study measured concentrations of mercury in invertebrates of the Okefenokee Swamp in Georgia, focusing on levels in amphipods, odonates, and crayfish. We collected and analyzed total mercury levels in these invertebrates from 32 sampling stations across commonly occurring sub-habitats. Sampling was conducted in December, May, and August over a two-year period. The highest levels of mercury were detected in amphipods, with total mercury levels often in excess of 20 ppm. Bioaccumulation pathways of mercury in invertebrates of the Okefenokee are probably complex; despite being larger and higher in the food chain, levels in odonates and crayfish were much lower than in amphipods. Mercury levels in invertebrates varied temporally with the highest levels detected in May. There was a lack of spatial variation in mercury levels which is consistent with aerial deposition of mercury. - This study measured mercury levels in invertebrates and found the highest levels in amphipods

  1. A pilot study testing a natural and a synthetic Molluscicide for controlling invasive apple snails (Pomacea maculata)

    Science.gov (United States)

    Olivier, Heather M.; Jenkins, Jill A.; Berhow, Mark; Carter, Jacoby

    2016-01-01

    Pomacea maculata (formerly P. insularum), an apple snail native to South America, was discovered in Louisiana in 2008. These snails strip vegetation, reproduce at tremendous rates, and have reduced rice production and caused ecosystem changes in Asia. In this pilot study snails were exposed to two molluscicides, a tea (Camellia sinensis) seed derivative (TSD) or niclosamide monohydrate (Pestanal®, 2′,5-dichloro-4′-nitrosalicylanilide, CAS #73360-56-2). Mortality was recorded after exposure to high or low concentrations (0.03 and 0.015 g/L for TSD, 1.3 and 0.13 mg/L for niclosamide). The TSD induced 100 % mortality at both concentrations. Niclosamide caused 100 % and 17 % mortality at high and low concentrations respectively. These molluscicides were also tested on potential biocontrol agents, the red swamp crayfish (Procambarus clarkii) and redear sunfish (Lepomis microlophus). No crayfish mortalities occurred at either concentration for either chemical, but sunfish experienced 100 % mortality with TSD (0.03 g/L), and 21 % mortality with niclosamide (0.13 mg/L).

  2. YEAR CYCLE OF AUSTROPOTAMOBIUS TORRENTIUM (SCHRANK IN STREAMS ON MEDVEDNICA MOUNTAIN (CROATIA.

    Directory of Open Access Journals (Sweden)

    MAGUIRE I.

    2002-07-01

    Full Text Available We studied life cycle of stone crayfish for 18 months in three streams on Medvednica Mountain, located above city of Zagreb. Sampling of animals was carried out with baited traps twice a month and various physiological functions were recorded. Sex ratio of trapped crayfish was 1:1, but it fluctuated during the year. Animals were active from early spring until the beginning of November when their activities significantly decreased. In this period we noticed three peaks of higher activity. The first one after winter starvation in March, the second one after egg hatching (June/July and the third one during mating period (end of September - beginning of November. The maximal recorded weight for female was 38 g while the heaviest male was 55 g. The longest female was 9.28 cm and male 10.30 cm. Development of glair glands started from the end of July, mating occurred at the end of October and the juveniles hatched until mid-June. Freshly moulted animals were found from mid-May until mid-October. Main injuries were claw and limb loss. We noticed the presence of burn spot disease and Branchiobdella parasita Henle within studied populations. Correlation with five different physico-chemical parameters of water showed that animals’ activity is positively correlated to water temperature, conductivity, pH and hardness and negatively to oxygen concentration.

  3. Revisiting reproduction and population structure and dynamics of Procambarus clarkii eight years after its introduction into Lake Trasimeno (Central Italy

    Directory of Open Access Journals (Sweden)

    Dörr A.J.M.

    2013-06-01

    Full Text Available Understanding population dynamics and regulation is fundamental for predicting establishment and spread of invasive alien species. In addition, the population biology of invasive alien species offers an opportunity to study basic ecological processes. In this context, we investigated reproductive and growth plasticity in the invasive crayfish Procambarus clarkii in Lake Trasimeno (central Italy. In total, 3153 crayfish were collected monthly from June 2007 to July 2009. The molt status was assessed by evaluating the exoskeleton hardness. To assess the reproductive cycle, the gonado-somatic and wet hepato-somatic indices were calculated for females. The reproductive status of males was appraised as well. We estimated growth and longevity using the von Bertalanffy growth function, and calculated the total, natural and fishing mortality indices. We then compared our present data with those obtained from the same population eight years before. Our results indicate some changes in population dynamics and in both molting and reproductive periods since the initial invasion of the shallow lake investigated. Long-term differences in the life history of the Trasimeno population may be the result of selective pressures different from those of the native range, but may also result from colonization events and human interference caused by professional fishing activities.

  4. Estimating age composition in Alpine native populations of Austropotamobius pallipes complex

    Directory of Open Access Journals (Sweden)

    Daniela Ghia

    2015-03-01

    Full Text Available Assessing the population structure and understanding growth patterns is crucial to manage freshwater resources and to solve fundamental questions concerning endangered species conservation. Austropotamobius pallipes (Lereboullet, 1858 species complex has been declining on a widespread basis in Europe, including Italy, but detailed data on population structure and growth are lacking. In four mountain streams populated by the species, water temperature data were collected by data-loggers. In July 2012, a total of 746 crayfish were collected at night and their length was measured. Females and males size distributions were analysed separately for each stream using Bhattacharya’s Method. Age was assigned to each length class. The mean values of the age classes were used to evaluate the growth rate of Von Bertalanffy, by the seasonalized equation. Up to six age classes were identified in two populations. Results show that three out of four populations are well-structured, and they confirm that A. pallipes complex is a K-selected species. We stress the need for long-term monitoring and the importance of obtained results in development of conservation plans of endangered crayfish.

  5. Life History Variation in Invading Applesnails (Pomacea canaliculata) May Pose Ecological Threats to Wetlands

    Science.gov (United States)

    Marfurt, R. K.; Boland, B. B.; Burks, R. L.

    2005-05-01

    In native habitats, channeled applesnails (Pomacea canaliculata) graze periphyton. However, casual observations from introduced populations suggest these invaders show variation in feeding ecology, predator response and life history strategies. Attempts to predict this consumer influence on ecosystem function suffer from a lack of basic data. We tested how salinity affected snail mortality. Both adults and hatchlings tolerated salinity levels up to 8 ppt. Adult feeding on lettuce increased significantly at 8 ppt compared to 0 ppt (p = 0.002), while hatchling consumption of algae did not vary (p = 0.284). To see how these consumers responded to predators from the invaded ecosystem, we tested behavioural responses to predatory cues from fish, turtles, crayfish and adult applesnails. Results indicated that fish and crayfish prompted similar predator-avoidance behaviors in hatchlings (p's 0.05) between native (ramshorn) and exotic applesnails, whereas adult fish consumed more applesnails (x2, p < 0.001). Our current efforts focus on examining if predator presence or macrophyte choice alters applesnail feeding rates. Research providing insight into the basic ecology of applesnails can foster management efforts at the ecosystem scale.

  6. White spot syndrome virus inactivation study by using gamma irradiation

    Science.gov (United States)

    Heidareh, Marzieh; Sedeh, Farahnaz Motamedi; Soltani, Mehdi; Rajabifar, Saeed; Afsharnasab, Mohammad; Dashtiannasab, Aghil

    2014-09-01

    The present study was conducted to investigate the effect of gamma irradiation on white spot syndrome virus (WSSV). White spot syndrome virus is a pathogen of major economic importance in cultured penaeid shrimp industries. White spot disease can cause mortalities reaching 100% within 3-10 days of gross signs appearing. During the period of culture, immunostimulant agents and vaccines may provide potential methods to protect shrimps from opportunistic and pathogenic microrganisms. In this study, firstly, WSSV was isolated from infected shrimp and then multiplied in crayfish. WSSV was purified from the infected crayfish haemolymph by sucrose gradient and confirmed by transmission electron microscopy. In vivo virus titration was performed in shrimp, Penaeus semisulcatus. The LD50 of live virus stock was calculated 10 5.4/mL. Shrimp post-larvae (1-2 g) were treated with gamma-irradiated (different doses) WSSV (100 to 10-4 dilutions) for a period of 10 days. The dose/survival curve for irradiated and un-irradiated WSSV was drawn; the optimum dose range for inactivation of WSSV and unaltered antigenicity was obtained 14-15 kGy. This preliminary information suggests that shrimp appear to benefit from treatment with gammairradiated WSSV especially at 14-15 KGy.

  7. MARS: A protein family involved in the formation of vertical skeletal elements.

    Science.gov (United States)

    Abehsera, Shai; Peles, Shani; Tynyakov, Jenny; Bentov, Shmuel; Aflalo, Eliahu D; Li, Shihao; Li, Fuhua; Xiang, Jianhai; Sagi, Amir

    2017-05-01

    Vertical organizations of skeletal elements are found in various vertebrate teeth and invertebrate exoskeletons. The molecular mechanism behind the development of such structural organizations is poorly known, although it is generally held that organic matrix proteins play an essential role. While most crustacean cuticular organizations exhibit horizontal chitinous layering, a typical vertical organization is found towards the surface of the teeth in the mandibles of the crayfish Cherax quadricarinatus. Candidate genes encoding for mandible-forming structural proteins were mined in C. quadricarinatus molt-related transcriptomic libraries by using a binary patterning approach. A new protein family, termed the Mandible Alanine Rich Structural (MARS) protein family, with a modular sequence design predicted to form fibers, was found. Investigations of spatial and temporal expression of the different MARS genes suggested specific expression in the mandibular teeth-forming epithelium, particularly during the formation of the chitinous vertical organization. MARS loss-of-function RNAi experiments resulted in the collapse of the organization of the chitin fibers oriented vertically to the surface of the crayfish mandibular incisor tooth. A general search of transcriptomic libraries suggested conservation of MARS proteins across a wide array of crustaceans. Our results provide a first look into the molecular mechanism used to build the complex crustacean mandible and into the specialized vertical structural solution that has evolved in skeletal elements. Copyright © 2017 Elsevier Inc. All rights reserved.

  8. Gill ATPase activity in Procambarus clarkii as an indicator of heavy metal pollution

    Energy Technology Data Exchange (ETDEWEB)

    Torreblanca, A.; Del Ramo, J.; Diaz-Mayans, J. (Univ. of Valencia (Spain))

    1989-06-01

    Lake Albufera and the surrounding rice field waters are subjected to very heavy loads of sewage and toxic industrial residues, including heavy metals, from the many urban and waste waters of this area. The American red crayfish, Procambarus clarkii have a high resistance to toxic effects of heavy metals. The sublethal effects of heavy metals on gills of fish and aquatic invertebrates have been extensively studied. Some metabolic disturbances and histologic damages have been reported, as well as osmoregulation alterations. However, little work has been done about the effect of heavy metals on Na,K and Mg-ATPases of freshwater invertebrate gills. Na,K-ATPase is the prime mediator of ion transport across cellular membranes and plays a central role in whole body ion regulation in marine and estuarine animals. Na,K-ATPase has been reviewed and assessed as a potentially useful indicator of pollution stress in aquatic animals. The purpose of this study is look for the relation, if any, between crayfish gill ATP-ase activity changes and metal exposure in laboratory. This find would allow the authors to assay this potential indicator in the field.

  9. Potential use of power plant reject heat in commercial aquaculture

    International Nuclear Information System (INIS)

    Olszewski, M.

    1977-01-01

    Current research and commercial activities in aquaculture operations have been reviewed. An aquaculture system using mostly herbivorous species in pond culture is proposed as a means of using waste heat to produce reasonably priced protein. The system uses waste water streams, such as secondary sewage effluent, animal wastes, or some industrial waste streams as a primary nutrient source to grow algae, which is fed to fish and clams. Crayfish feed on the clam wastes thereby providing a clean effluent from the aquaculture system. Alternate fish associations are presented and it appears that a carp or tilapia association is desirable. An aquaculture system capable of rejecting all the waste heat from a 1000-MW(e) power station in winter can accommodate about half the summer heat rejection load. The aquaculture facility would require approximately 133 ha and would produce 4.1 x 10 5 kg/year of fish, 1.5 x 10 6 kg/year of clam meat, and 1.5 x 10 4 kg/year of live crayfish. The estimated annual pretax profit from this operation is one million dollars. Several possible problem areas have been identified. However, technical solutions appear to be readily available to solve these problems. The proposed system shows considerable economic promise. Small scale experiments have demonstrated the technical feasibility of various components of the system. It therefore appears that a pilot scale experimental facility should be operated

  10. Tritium kinetics in a freshwater marsh ecosystem

    International Nuclear Information System (INIS)

    Adams, L.W.

    1976-01-01

    Ten curies of tritium (as tritiated water, HTO) were applied to a 2-ha enclosed Lake Erie marsh in northwestern Ohio on 29 October 1973. Tritium kinetics in the marsh water, bottom sediment, and selected aquatic plants and animals were determined. Following HTO application, peak tritium levels in the sediment were observed on day 13 in the top 1-cm layer, on day 27 at the 5-cm depth, and on day 64 at the 10-cm depth. Peak levels at 15 and 20 cm were not discernible, although there was some movement of HTO to the 20-cm depth. A model based on diffusion theory described tritium movement through the sediment. Unbound and bound tritium levels in curly-leaf pondweed (Potamogeton crispus), pickerelweed (Pontederia cordata), and smartweed (Polygonum lapathifolium) generally tended to follow tritium levels in marsh water. The unbound tritium:marsh water tritium ratio was significantly larger (P < 0.001) in curly-leaf pondweed than in either of the two emergents. Tritium uptake into the unbound compartments of crayfish (Procambarus blandingi), carp (Cyprinus carpio), and bluegills (Lepomis macrochirus) was rapid. For crayfish, maximum HTO levels were observed on days 3 and 2 for viscera and muscle, respectively. Unbound HTO in carp viscera peaked on day 2, and levels in carp muscle reached a maximum in 4 hours. Maximum levels of unbound HTO in bluegill viscera and muscle were observed on day 1. After peak levels were obtained, unbound HTO paralleled marsh water HTO activity in all species. Tritium uptake into the bound compartments was not as rapid nor were the levels as high as for unbound HTO in any of the species. Peak bound levels in crayfish viscera were observed on day 20 and maximum levels in muscle were noted on day 10. Bound tritium in carp viscera and muscle reached maximum levels on day 20. In bluegills, peaks were reached on days 7 and 5 for viscera and muscle, respectively. Bound tritium in all species decreased following maximum levels

  11. Simultaneous determination of UV-filters and estrogens in aquatic invertebrates by modified quick, easy, cheap, effective, rugged, and safe extraction and liquid chromatography tandem mass spectrometry.

    Science.gov (United States)

    He, Ke; Timm, Anne; Blaney, Lee

    2017-08-04

    Ultraviolet-filters (UV-filters) and estrogens have attracted increased attention as contaminants of emerging concern (CECs) due to their widespread occurrence in the environment. Most of these CECs are hydrophobic and have the potential to accumulate in aquatic organisms. To date, co-analysis of UV-filters and estrogens has not been reported due, in part, to the complex environmental matrices. Here, a multi-residue method has been developed for simultaneous determination of five UV-filters and three estrogens in tissue from aquatic and marine organisms. The procedure involved a modified Quick, Easy, Cheap, Effective, Rugged, and Safe (QuEChERS) extraction with a novel reverse-solid-phase extraction (reverse-SPE) cleanup in place of dispersive-SPE, followed by liquid chromatography tandem mass spectrometry (LC-MS/MS) analysis. The tissue mass, acetonitrile content, and salt conditions for QuEChERS extraction, along with the reverse-SPE cartridge material and elution conditions, were thoroughly investigated and optimized. Five UV-filters (i.e., 3-(4-methylbenzylidene) camphor, benzophenone-3, ethylhexylmethoxycinnamate, homosalate, and octocrylene) and three estrogens (i.e., estrone, 17β-estradiol, and 17α-ethinylestradiol) were simultaneously analyzed by taking advantage of wrong-way-round ionization in LC-MS/MS. The optimized analytical protocol exhibited good recoveries (>80%) for target compounds and enabled their detection at concentrations as low as 0.2ng/g in 50mg tissue samples. The method was applied to determine concentrations of target analytes in four invertebrates (i.e., Orconectes virilis, Procambarus clarkii, Crassostrea virginica, and Ischadium recurvum). All eight target analytes were detected at least once in the tissue samples, with the highest concentration being 399ng/g of homosalate in O. virilis. These results highlight the ubiquitous bioaccumulation of CECs in aquatic and marine invertebrates. Copyright © 2017 Elsevier B.V. All rights

  12. Effects of serotonin and fluoxetine on blood glucose regulation in two decapod species

    Directory of Open Access Journals (Sweden)

    Santos E.A.

    2001-01-01

    Full Text Available One of the best known crustacean hormones is the crustacean hyperglycemic hormone (CHH. However, the mechanisms involved in hormone release in these animals are poorly understood, and thus constitute the central objective of the present study. Different groups of crustaceans belonging to diverse taxa (Chasmagnathus granulata, a grapsid crab and Orconectes limosus, an astacid were injected with serotonin, fluoxetine, or a mixture of both, and glycemic values (C. granulata and O. limosus and CHH levels (O. limosus were determined after 2 h in either submerged animals or animals exposed to atmospheric air. Both serotonin and fluoxetine caused significant hyperglycemia (P<0.05 after injection into the blood sinus of the two species, an effect enhanced after exposure to atmospheric air. In C. granulata blood glucose increased from 6.1 to 43.3 and 11.4 mg/100 ml in submerged animals and from 5.7 to 55.2 and 22.5 mg/100 ml in air-exposed animals after treatment with serotonin and fluoxetine, respectively. In O. limosus the increases were from 1.2 to 59.7 and 135.2 mg/100 ml in submerged animals and from 2.5 to 200.3 and 193.6 mg/100 ml in air-exposed animals after treatment with serotonin and fluoxetine, respectively. Serotonin and fluoxetine also caused a significant increase in the circulating levels of CHH in O. limosus, from 11.9 to 43 and 45.7 fmol/ml in submerged animals and from 13.2 to 32.6 and 45.7 fmol/ml in air-exposed animals, respectively, thus confirming their action as neuroregulators in these invertebrates.

  13. Chronic toxicity of contaminated sediments on reproduction and histopathology of the crustacean Gammarus fossarum and relationship with the chemical contamination and in vitro effects

    Energy Technology Data Exchange (ETDEWEB)

    Mazurova, Edita; Hilscherova, Klara; Sidlova-Stepankova, Tereza; Blaha, Ludek [Faculty of Science, RECETOX, Research Centre for Environmental Chemistry and Ecotoxicology, Masaryk Univ., Brno (Czech Republic); Koehler, Heinz R. [Animal Physiological Ecology, Univ. of Tuebingen (Germany); Triebskorn, Rita [Steinbeis-Transfer Center for Ecotoxicology and Ecophysiology, Rottenburg (Germany); Jungmann, Dirk [Inst. of Hydrobiology, Dresden Univ. of Tech. (Germany); Giesy, John P. [Dept. of Veterinary Biomedical Sciences and Toxicology Centre, Univ. of Saskatchewan, Saskatoon (Canada); Zoology Dept., National Food Safety and Toxicology Center, and Center for Integrative Toxicology Center, and Center for Integrative Toxicology, Michigan State Univ., East Lansing, MI (United States); Biology and Chemistry Dept., City Univ. of Hong Kong, Kowloon, Hong Kong (China); School of the Environment, Nanjing Univ. (China)

    2010-04-15

    The aim of the present study was to investigate possible relationships between the sediment contaminants and the occurrence of intersex in situ. Two of the studied sediments were from polluted sites with increased occurrence of intersex crustaceans (Lake Pilnok, black coal mining area in the Czech Republic, inhabited by the crayfish Pontastacus leptodactylus population with 18% of intersex; creek Lockwitzbach in Germany with Gammarus fossarum population with about 7% of intersex). Materials and methods Sediments were studied by a combined approach that included (1) determination of concentrations of metals and traditionally analyzed organic pollutants such as polychlorinated biphenyls, pesticides, and polycyclic aromatic hydrocarbons (PAHs); (2) examination of the in vitro potencies to activate aryl hydrocarbon (AhR), estrogen (ER), and androgen receptor-mediated responses; and (3) in vivo whole sediment exposures during a 12-week reproduction toxicity study with benthic amphipod G. fossarum. (orig.)

  14. Actinide elements in aquatic and terrestrial environments

    International Nuclear Information System (INIS)

    Bondietti, E.A.

    1978-01-01

    Progress is reported in terrestrial ecology studies with regard to plutonium in biota from the White Oak Creek forest; comparative distribution of plutonium in two forest ecosystems; an ecosystem model of plutonium dynamics; actinide element metabolism in cotton rats; and crayfish studies. Progress is reported in aquatic studies with regard to transuranics in surface waters, frogs, benthic algae, and invertebrates from pond 3513; and radioecology of transuranic elements in cotton rats bordering waste pond 3513. Progress is also reported in stability of trivalent plutonium in White Oak Lake water; chemistry of plutonium, americium, curium, and uranium in pond water; uranium, thorium, and plutonium in small mammals; and effect of soil pretreatment on the distribution of plutonium

  15. Organic coolant in Winnipeg riverbed sediments

    International Nuclear Information System (INIS)

    Guthrie, J.E.; Acres, O.E.

    1979-03-01

    Between January and May 1977 a prolonged leak of organic coolant occurred from the Whiteshell Nuclear Research Establishment's nuclear reactor, and a minimum of 1450 kg of coolant entered the Winnipeg River and was deposited on the riverbed. The level of radioactivity associated with this coolant was low, contributing less than 0.2 μGy (0.02 mrad) a year to the natural background gamma radiation field from the riverbed. The concentration of coolant in the water samples never exceeded 0.02 mg/L, the lower limit of detection. The mortality of crayfish, held in cages where the riverbed was covered with the largest deposits of coolant, was not significantly different from that in the control cages upstream of the outfall. No evidence of fish kill was found. (author)

  16. Artificial lateral line with biomimetic neuromasts to emulate fish sensing

    International Nuclear Information System (INIS)

    Yang Yingchen; Chen Nannan; Tucker, Craig; Hu Huan; Liu Chang; Nguyen, Nam; Lockwood, Michael; Jones, Douglas L; Bleckmann, Horst

    2010-01-01

    Hydrodynamic imaging using the lateral line plays a critical role in fish behavior. To engineer such a biologically inspired sensing system, we developed an artificial lateral line using MEMS (microelectromechanical system) technology and explored its localization capability. Arrays of biomimetic neuromasts constituted an artificial lateral line wrapped around a cylinder. A beamforming algorithm further enabled the artificial lateral line to image real-world hydrodynamic events in a 3D domain. We demonstrate that the artificial lateral line system can accurately localize an artificial dipole source and a natural tail-flicking crayfish under various conditions. The artificial lateral line provides a new sense to man-made underwater vehicles and marine robots so that they can sense like fish.

  17. Annual report of ecological research at the Savannah River Ecology Laboratory

    International Nuclear Information System (INIS)

    1976-05-01

    Studies on mineral cycling are concerned with availability of stable elements and radionuclides to the biota of the southeastern coastal plain; the role of primary producers, consumers, and detritivores in cycling processes; the factors that limit or regulate rate processes in southeastern ecosystems; the importance of interactions among energy flow, thermal environments, and mineral cycling processes on rates of biomass buildup and transfer within southeastern ecosystems; the extent to which transfer coefficients are modified by population processes that influence the temporal or spatial turnover of compartmental standing crops; and the validation of models of cycling processes in southeastern ecosystems at various sites on the southeastern coastal plain. Research in thermal ecology is being conducted on macrophytes, snails, fishes, high parasites, shrimp, crayfish, turtles, and alligators

  18. Life history and ecology of Cambarus halli (Hobbs)

    Science.gov (United States)

    Dennard, S.; Peterson, J.T.; Hawthorne, E.S.

    2009-01-01

    The life history of Cambarus halli, a crayfish endemic to the Tallapoosa River Basin, GA, was studied at four sites within the Tallapoosa River. Two sites had allopatric populations of C. halli, and two sites had populations of C. halli sympatric with C. englishi. Three age classes existed across sites. For Cambarus halli, total number of pleopodal eggs was positively related to carapace length, but egg size was only weakly positively related to carapace length. Cambarus halli were smaller across age classes at sympatric sites, but had greater growth rates than at allopatric sites. Cambarus halli density estimates were lower at sympatric sites, while proportions of reproductively active age-1 and age-2 individuals were higher at allopatric sites (63% vs. 33%).

  19. A new genus and species of entocytherid ostracod (Ostracoda: Entocytheridae) from the John Day River Basin of Oregon, U.S.A., with a key to genera of the subfamily Entocytherinae.

    Science.gov (United States)

    Weaver, Patricia G; Williams, Bronwyn W

    2017-06-07

    Targeted sampling efforts by the authors for the signal crayfish, Pacifastacus leniusculus, from its native range in the John Day River Basin, Oregon, U.S.A. yielded entocytherid ostracods with a male copulatory complex so clearly different from other entocytherines that a new genus, Aurumcythere gen. nov. is proposed to receive them. This newly proposed, apparently nonsclerotized, genus with hook and spur-like prominences of the posteroventral end of the peniferum is the first new genus of the subfamily Entocytherinae named since Hobbs & Peters described Aphelocythere (= Waltoncythere) in 1977. Aurumcythere gen. nov. represents only the second genus of entocytherid known from the Pacific Northwest. Lack of sclerotization in Aurumcythere gen. nov. provides new insight into poorly understood mating behaviors of entocytherid ostracods.

  20. Aquatic Nuisance Species Locator

    Science.gov (United States)

    Data in this map has been collected by the United States Geological Survey's Nonindigenous Aquatic Species program located in Gainesville, Florida (http://nas.er.usgs.gov/default.aspx). This dataset may have some inaccuracies and is only current to June 15, 2012. The species identified in this dataset are not inclusive of all aquatic nuisance species, but rather a subset identified to be at risk for transport by recreational activities such as boating and angling. Additionally, the locations where organisims have been identified are also not inclusive and should be treated as a guide. Organisms are limited to the following: American bullfrog, Asian clam, Asian shore crab, Asian tunicate, Australian spotted jellyfish, Chinese mitten crab, New Zealand mudsnail, Colonial sea squirt, Alewife, Bighead carp, Black carp, Flathead catfish, Grass carp, Green crab, Lionfish, Northern snakehead, Quagga mussel, Round Goby, Ruffe, Rusty crayfish, Sea lamprey, Silver carp, Spiny water flea, Veined rapa whelk, Zebra mussel

  1. Information to support to monitoring and habitat restoration on Ash Meadows National Wildlife Refuge

    Science.gov (United States)

    Scoppettone, G. Gary

    2013-01-01

    The Ash Meadows National Wildlife Refuge staff focuses on improving habitat for the highest incidence of endemic species for an area of its size in the continental United States. Attempts are being made to restore habitat to some semblance of its pre-anthropogenic undisturbed condition, and to provide habitat conditions to which native plant and animal species have evolved. Unfortunately, restoring the Ash Meadows’ Oases to its pre-anthropogenic undisturbed condition is almost impossible. First, there are constraints on water manipulation because there are private holdings within the refuge boundary; second, there has been at least one species extinction—the Ash Meadows pool fish (Empetrichthys merriami). It is also quite possible that thermal endemic invertebrate species were lost before ever being described. Perhaps the primary obstacle to restoring Ash Meadows to its pre-anthropogenic undisturbed conditions is the presence of invasive species. However, invasive species, such as red swamp crayfish (Procambarus clarki) and western mosquitofish (Gambusia affinis), are a primary driving force in restoring Ash Meadows’ spring systems, because under certain habitat conditions they can all but replace native species. Returning Ash Meadows’ physical landscape to some semblance of its pre-anthropogenic undisturbed condition through natural processes may take decades. Meanwhile, the natural dissolution of concrete and earthen irrigation channels threatens to allow cattail marshes to flourish instead of spring-brooks immediately downstream of spring discharge. This successional stage favors non-native crayfish and mosquitofish over the native Amargosa pupfish (Cyprinodon nevadensis). Thus, restoration is needed to control non-natives and to promote native species, and without such intervention the probability of native fish reduction or loss, is anticipated. The four studies in this report are intended to provide information for restoring native fish habitat and

  2. Oxygen uptake by excised gills of Procambarus clarkii (Girard) from Albufera Lake of Valencia, Spain, under heavy metal treatments

    Energy Technology Data Exchange (ETDEWEB)

    Diaz-Mayans, J.; Torreblanca, A.; Del Ramo, J.; Nunez, A.

    1986-06-01

    The American red crayfish Procambarus clarkii, originally from Louisiana (USA) was introduced in Spain in the 70's in the Guadalquivir River swamps. It appeared first randomly and in a more regular basis afterwards since 1978 in the Albufera Lake south of Valencia and in the surrounding rice fields. Albufera lake and surrounding rice fields waters are being subject since the last three decades to very heavy load of sewage, toxic industrial residues including heavy metals and pesticides from the many urban and industrial settlements in the zone. In the present study, the authors have investigated the effect that heavy metals (Chromium, Cadmium and Mercury) have on the oxygen uptake by excised bills of Procambarus clarkii (Girard) coming from the Albufera Lake (Valencia).

  3. Acute silver toxicity in aquatic animals is a function of sodium uptake rate

    DEFF Research Database (Denmark)

    Bianchini, A.; Grosell, Martin Hautopp; Gregory, S.

    2002-01-01

    -specific surface area of the gills depends on animal body mass; and (iv) the gill surface is also the major site of Na+ loss by diffusion, we hypothesized that whole body Na+ uptake rate (i.e., turnover rate) and secondarily body mass would be good predictors of acute silver toxicity. Results obtained from...... toxicological (LC50 of AgNO3) and physiological (22Na uptake rate) tests performed on juvenile fish (rainbow trout, Oncorhynchus mykiss), early juvenile and adult crayfish (Cambarus diogenes diogenes), and neonate and adult daphnids (Daphnia magna) in moderately hard water of constant quality support the above...... hypothesis. Therefore, sensitivity to AgNO3, in terms of either total measured silver or free Ag+, was reliably predicted from the whole body Na+ uptake rate in animals with body mass ranging over 6 orders of magnitude (from micrograms to grams). A positive log-log correlation between acute AgNO3 toxicity...

  4. Increasing Potential Risk of a Global Aquatic Invader in Europe in Contrast to Other Continents under Future Climate Change

    Science.gov (United States)

    Liu, Xuan; Guo, Zhongwei; Ke, Zunwei; Wang, Supen; Li, Yiming

    2011-01-01

    Background Anthropogenically-induced climate change can alter the current climatic habitat of non-native species and can have complex effects on potentially invasive species. Predictions of the potential distributions of invasive species under climate change will provide critical information for future conservation and management strategies. Aquatic ecosystems are particularly vulnerable to invasive species and climate change, but the effect of climate change on invasive species distributions has been rather neglected, especially for notorious global invaders. Methodology/Principal Findings We used ecological niche models (ENMs) to assess the risks and opportunities that climate change presents for the red swamp crayfish (Procambarus clarkii), which is a worldwide aquatic invasive species. Linking the factors of climate, topography, habitat and human influence, we developed predictive models incorporating both native and non-native distribution data of the crayfish to identify present areas of potential distribution and project the effects of future climate change based on a consensus-forecast approach combining the CCCMA and HADCM3 climate models under two emission scenarios (A2a and B2a) by 2050. The minimum temperature from the coldest month, the human footprint and precipitation of the driest quarter contributed most to the species distribution models. Under both the A2a and B2a scenarios, P. clarkii shifted to higher latitudes in continents of both the northern and southern hemispheres. However, the effect of climate change varied considerately among continents with an expanding potential in Europe and contracting changes in others. Conclusions/Significance Our findings are the first to predict the impact of climate change on the future distribution of a globally invasive aquatic species. We confirmed the complexities of the likely effects of climate change on the potential distribution of globally invasive species, and it is extremely important to develop

  5. State-changes in the swimmeret system: a neural circuit that drives locomotion.

    Science.gov (United States)

    Tschuluun, N; Hall, W M; Mulloney, B

    2009-11-01

    The crayfish swimmeret system undergoes transitions between a silent state and an active state. In the silent state, no patterned firing occurs in swimmeret motor neurons. In the active state, bursts of spikes in power stroke motor neurons alternate periodically with bursts of spikes in return stroke motor neurons. In preparations of the isolated crayfish central nervous system (CNS), the temporal structures of motor patterns expressed in the active state are similar to those expressed by the intact animal. These transitions can occur spontaneously, in response to stimulation of command neurons, or in response to application of neuromodulators and transmitter analogues. We used single-electrode voltage clamp of power-stroke exciter and return-stroke exciter motor neurons to study changes in membrane currents during spontaneous transitions and during transitions caused by bath-application of carbachol or octopamine (OA). Spontaneous transitions from silence to activity were marked by the appearance of a standing inward current and periodic outward currents in both types of motor neurons. Bath-application of carbachol also led to the development of these currents and activation of the system. Using low Ca(2+)-high Mg(2+) saline to block synaptic transmission, we found that the carbachol-induced inward current included a direct response by the motor neuron and an indirect component. Spontaneous transitions from activity to silence were marked by disappearance of the standing inward current and the periodic outward currents. Bath-application of OA led promptly to the disappearance of both currents, and silenced the system. OA also acted directly on both types of motor neurons to cause a hyperpolarizing outward current that would contribute to silencing the system.

  6. Plastic responses of a sessile prey to multiple predators: a field and experimental study.

    Directory of Open Access Journals (Sweden)

    Philipp Emanuel Hirsch

    Full Text Available Theory predicts that prey facing a combination of predators with different feeding modes have two options: to express a response against the feeding mode of the most dangerous predator, or to express an intermediate response. Intermediate phenotypes protect equally well against several feeding modes, rather than providing specific protection against a single predator. Anti-predator traits that protect against a common feeding mode displayed by all predators should be expressed regardless of predator combination, as there is no need for trade-offs.We studied phenotypic anti-predator responses of zebra mussels to predation threat from a handling-time-limited (crayfish and a gape-size-limited (roach predator. Both predators dislodge mussels from the substrate but diverge in their further feeding modes. Mussels increased expression of a non-specific defense trait (attachment strength against all combinations of predators relative to a control. In response to roach alone, mussels showed a tendency to develop a weaker and more elongated shell. In response to crayfish, mussels developed a harder and rounder shell. When exposed to either a combination of predators or no predator, mussels developed an intermediate phenotype. Mussel growth rate was positively correlated with an elongated weaker shell and negatively correlated with a round strong shell, indicating a trade-off between anti-predator responses. Field observations of prey phenotypes revealed the presence of both anti-predator phenotypes and the trade-off with growth, but intra-specific population density and bottom substrate had a greater influence than predator density.Our results show that two different predators can exert both functionally equivalent and inverse selection pressures on a single prey. Our field study suggests that abiotic factors and prey population density should be considered when attempting to explain phenotypic diversity in the wild.

  7. Predator diversity effects in an exotic freshwater food web.

    Science.gov (United States)

    Naddafi, Rahmat; Rudstam, Lars G

    2013-01-01

    Cascading trophic interactions are often defined as the indirect effects of a predator on primary producers through the effect of the predator on herbivores. These effects can be both direct through removal of herbivores [density-mediated indirect interactions (DMIIs)] or indirect through changes in the behavior of the herbivores [trait-mediated indirect interactions (TMIIs)]. How the relative importance of these two indirect interactions varies with predator diversity remains poorly understood. We tested the effect of predator diversity on both TMIIs and DMIIs on phytoplankton using two competitive invasive dreissenid mussel species (zebra mussel and quagga mussel) as the herbivores and combinations of one, two or all three species of the predators pumpkinseed sunfish, round goby, and rusty crayfish. Predators had either direct access to mussels and induced both TMII and DMII, or no direct access and induced only TMII through the presence of risk cues. In both sets of treatments, the predators induced a trophic cascade which resulted in more phytoplankton remaining with predators present than with only mussels present. The trophic cascade was weaker in three-predator and two-predator treatments than in one-predator treatments when predators had direct access to dreissenids (DMIIs and TMIIs). Crayfish had higher cascading effects on phytoplankton than both pumpkinseed and round goby. Increased predator diversity decreased the strength of DMIIs but had no effect on the strength of TMIIs. The strength of TMIIs was higher with zebra than quagga mussels. Our study suggests that inter-specific interference among predators in multi-species treatments weakens the consumptive cascading effects of predation on lower trophic levels whereas the importance of predator diversity on trait mediated effects depends on predator identity.

  8. Crustacean hyperglycemic hormone (cHH as a modulator of aggression in crustacean decapods.

    Directory of Open Access Journals (Sweden)

    Laura Aquiloni

    Full Text Available Biogenic amines, particularly serotonin, are recognised to play an important role in controlling the aggression of invertebrates, whereas the effect of neurohormones is still underexplored. The crustacean Hyperglycemic Hormone (cHH is a multifunctional member of the eyestalk neuropeptide family. We expect that this neuropeptide influences aggression either directly, by controlling its expression, or indirectly, by mobilizing the energetic stores needed for the increased activity of an animal. Our study aims at testing such an influence and the possible reversion of hierarchies in the red swamp crayfish, Procambarus clarkii, as a model organism. Three types of pairs of similarly sized males were formed: (1 'control pairs' (CP, n = 8: both individuals were injected with a phosphate saline solution (PBS; (2 'reinforced pairs' (RP, n = 9: the alpha alone was injected with native cHH, and the beta with PBS; (3 'inverted pairs' (IP, n = 9: the opposite of (2. We found that, independently of the crayfish's prior social experience, cHH injections induced (i the expression of dominance behaviour, (ii higher glycemic levels, and (iii lower time spent motionless. In CP and RP, fight intensity decreased with the establishment of dominance. On the contrary, in IP, betas became increasingly likely to initiate and escalate fights and, consequently, increased their dominance till a temporary reversal of the hierarchy. Our results demonstrate, for the first time, that, similarly to serotonin, cHH enhances individual aggression, up to reverse, although transitorily, the hierarchical rank. New research perspectives are thus opened in our intriguing effort of understanding the role of cHH in the modulation of agonistic behaviour in crustaceans.

  9. The Emergence and Epidemiology of Haff Disease in China

    Directory of Open Access Journals (Sweden)

    Thomas Y. K. Chan

    2016-12-01

    Full Text Available Haff disease is a rare syndrome of unexplained myalgia and rhabdomyolysis occurring within 24 h of consumption of certain types of cooked freshwater fish or crustacean. It is caused by a yet unidentified heat-stable toxin. In the present review of published case studies and official press releases, the main objective is to report the emergence and epidemiology of Haff disease in China. Haff disease first occurred in Beijing in 2000 and in Lianzhou and Liannan, Guangdong Province in 2009. Subsequent outbreaks mostly occurred in the Jiangsu Province—Nanjing, Yangzhou, Huai’an, and Yancheng. Isolated outbreaks occurred in other cities since 2010—Shijiazhuang, Yueyang, Shanghai, Wuhu, Baoding, Shenzhen, and Hong Kong (imported cases from Shenzhen. Outbreaks occurred predominately in the summer. Crayfish accounted for almost all the outbreaks. Two large outbreaks occurred in Lianzhou and Liannan in 2009 (n = 54 after eating pomfrets and in Nanjing in 2010 (n = 42 after eating crayfish. Other reports or outbreaks involved only 1–9 subjects (median 2 subjects. Variability in individual susceptibility and attack rates were noted, with many subjects remaining asymptomatic despite sharing the same seafood meal as the index cases. Adults were predominately involved. Symptoms occurred within 3–20 h of seafood ingestion, including myalgia, weakness, and, less frequently, nausea, vomiting, abdominal pain, and diarrhea. Myalgia and muscle weakness should normally subside within 2–3 days. Serum creatine phosphokinase became normal within 5–6 days. Abnormal renal function was uncommon. Serious complications (renal failure, multi-organ failure, and prolonged myopathy and death were rare. In any subjects with unexplained myalgia and rhabdomyolysis, seafood consumption should be included in the history. All suspected cases of Haff disease, including milder presentations, should be reported to public health authorities.

  10. Behavioral and electrophysiological studies of radiation detection in a freshwater crustacean

    International Nuclear Information System (INIS)

    Rodriguez, A.; Kimeldorf, D.J.

    1976-01-01

    Behavioral and electrophysiological studies were done on the crayfish (Pacifastacus trowbridgii Stimpson) to determine its ability to detect exposure to 300 kVp x rays. Behavioral arousal responses were observed at exposure rates of 10 to 30 R/sec. Wholebody and partial-body exposures of eye-stalkless (blinded) animals also induced similar responses and indicated a radiation-sensitive receptor in the abdomen. Prolonged exposure under free choice of residence conditions induced an avoidance of the x-ray field. X-ray exposure of the dark-adapted compound eye evoked an electroretinogram (ERG) that was similar to the light-evoked ERG. The ERG amplitude was directly proportional to the total exposure with exposures less than 300 msec duration and related to the logarithm of the exposure rate with exposures greater than 300 msec. X-ray exposure of receptor sites on the medial branch of the antennule and the cheliped of the first walking-leg did not yield any significant chemoreceptor responses as judged by electrophysiological tests. X-irradiation of the sixth abdominal ganglion in both isolated and in vivo preparations elicited significant increases in neural impulse activity. The latency varied inversely with exposure rate. Spike potentials evoked by x rays were similar to those evoked by light; however, a supplemental increase in spikes of lower amplitude occurred that did not occur during light stimulation. It appears likely that the behavioral response in the crayfish, subjected to abdomen-only exposure, may be instigated by x-ray excitation of the sixth ganglion

  11. Understanding the dynamical control of animal movement

    Science.gov (United States)

    Edwards, Donald

    2008-03-01

    Over the last 50 years, neurophysiologists have described many neural circuits that transform sensory input into motor commands, while biomechanicians and behavioral biologists have described many patterns of animal movement that occur in response to sensory input. Attempts to link these two have been frustrated by our technical inability to record from the necessary neurons in a freely behaving animal. As a result, we don't know how these neural circuits function in the closed loop context of free behavior, where the sensory and motor context changes on a millisecond time-scale. To address this problem, we have developed a software package, AnimatLab (www.AnimatLab.com), that enables users to reconstruct an animal's body and its relevant neural circuits, to link them at the sensory and motor ends, and through simulation, to test their ability to reproduce appropriate patterns of the animal's movements in a simulated Newtonian world. A Windows-based program, AnimatLab consists of a neural editor, a body editor, a world editor, stimulus and recording facilities, neural and physics engines, and an interactive 3-D graphical display. We have used AnimatLab to study three patterns of behavior: the grasshopper jump, crayfish escape, and crayfish leg movements used in postural control, walking, reaching and grasping. In each instance, the simulation helped identify constraints on both nervous function and biomechanical performance that have provided the basis for new experiments. Colleagues elsewhere have begun to use AnimatLab to study control of paw movements in cats and postural control in humans. We have also used AnimatLab simulations to guide the development of an autonomous hexapod robot in which the neural control circuitry is downloaded to the robot from the test computer.

  12. Predator diversity effects in an exotic freshwater food web.

    Directory of Open Access Journals (Sweden)

    Rahmat Naddafi

    Full Text Available Cascading trophic interactions are often defined as the indirect effects of a predator on primary producers through the effect of the predator on herbivores. These effects can be both direct through removal of herbivores [density-mediated indirect interactions (DMIIs] or indirect through changes in the behavior of the herbivores [trait-mediated indirect interactions (TMIIs]. How the relative importance of these two indirect interactions varies with predator diversity remains poorly understood. We tested the effect of predator diversity on both TMIIs and DMIIs on phytoplankton using two competitive invasive dreissenid mussel species (zebra mussel and quagga mussel as the herbivores and combinations of one, two or all three species of the predators pumpkinseed sunfish, round goby, and rusty crayfish. Predators had either direct access to mussels and induced both TMII and DMII, or no direct access and induced only TMII through the presence of risk cues. In both sets of treatments, the predators induced a trophic cascade which resulted in more phytoplankton remaining with predators present than with only mussels present. The trophic cascade was weaker in three-predator and two-predator treatments than in one-predator treatments when predators had direct access to dreissenids (DMIIs and TMIIs. Crayfish had higher cascading effects on phytoplankton than both pumpkinseed and round goby. Increased predator diversity decreased the strength of DMIIs but had no effect on the strength of TMIIs. The strength of TMIIs was higher with zebra than quagga mussels. Our study suggests that inter-specific interference among predators in multi-species treatments weakens the consumptive cascading effects of predation on lower trophic levels whereas the importance of predator diversity on trait mediated effects depends on predator identity.

  13. Seasonal variation of the effect of high-carbohydrate and high-protein diets on the intermediate metabolism of Parastacus brasiliensis (Crustacea, Decapoda, Parastacidae maintained in the laboratory Variações sazonais do efeito de uma dieta rica em carboidrato e rica em proteínas no metabolismo intermediário de Parastacus brasiliensis (Crustacea, Decapoda, Parastacidae mantidos em laboratório

    Directory of Open Access Journals (Sweden)

    Bibiana K. Dutra

    2008-12-01

    Full Text Available The goal of this study was to evaluate the effect of a high-carbohydrate diet (HC and a high-protein diet (HP on the metabolism of the crayfish Parastacus brasiliensis (Von Martens, 1869, collected in different seasons and maintained in the laboratory for 15 days. Crayfish were collected monthly from January 2002 to January 2004 at São Francisco de Paula, Southern Brazil, in Guarapirá stream. In the laboratory, the animals were kept submerged in aquariums under controlled conditions. They were fed ad libitum, for 15 days with either a HC or HP diet. At the end of this period, haemolymph samples were collected, as were hepatopancreas, gills, and abdominal muscle that were removed for determination of glycogen, free glucose, lipids, and triglycerides. The haemolymph samples were used for determination of glucose, proteins, lipids, and triglycerides. Statistical analysis (ANOVA revealed significant seasonal differences in biochemical composition in crayfish maintained on HC or HP diets. Independent of the diets offered to the animals and the controlled conditions for 15 days, the indications of seasonality were unchanged. The observed changes seemed to be related to the reproductive period. Moreover, the HC diet increased all energy reserves in adult parastacids, which may aid in reproduction.O objetivo deste estudo foi avaliar o efeito da dieta rica em carboidratos (HC e da dieta rica em proteínas (HP sobre o metabolismo do Parastacus brasiliensis (Von Martens, 1869 coletados em diferentes estações e mantidos durante 15 dias em laboratório. Os lagostins foram coletados mensalmente de Janeiro de 2002 a Janeiro de 2004 em São Francisco de Paula, Sul do Brasil, no riacho Guarapirá. No laboratório, os animais foram mantidos submersos em aquários sob condições controladas. Eles foram alimentados ad libitum por 15 dias com a dieta HC ou HP. Após o final do período, as amostras de hemolinfa foram coletadas, assim como o hepatopâncreas, as

  14. ÉVOLUTION DE LA RÉPARTITION DES ÉCREVISSES EN FRANCE MÉTROPOLITAINE SELON LES ENQUÊTES NATIONALES MENÉES PAR LE CONSEIL SUPÉRIEUR DE LA PÊCHE DE 1977 À 2001

    Directory of Open Access Journals (Sweden)

    CHANGEUX T.

    2003-04-01

    Full Text Available Selon les enquêtes nationales menées par le Conseil supérieur de la pêche depuis 1977 en France métropolitaine, la répartition des espèces d’écrevisses montre que les espèces autochtones (Austropotamobius pallipes, Astacus astacus, Austropotamobius torrentium sont soit rares, soit en forte régression, alors que les espèces introduites (Orconectes limosus, Pacifastacus leniusculus, Procambarus clarkii, Astacus leptodactylus progressent. L’interdiction de transport vivant des espèces introduites, à l’exception d’A. leptodactylus, n’a pas enrayé le phénomène avec une accélération particulière de la progression de P. leniusculus ces cinq dernières années, certainement responsable de la recrudescence des cas de peste (Aphanomyces astaci. Les autres mesures favorisant les espèces autochtones, comme la limitation des prélèvements par pêche et les programmes de réintroduction, n’inversent pas la tendance. Il semble donc nécessaire de développer une politique de conservation centrée sur la préservation de l’habitat et le respect de certaines règles de prophylaxie à déterminer. Cela ne peut s’envisager que sur des bassins versants de petite surface facilement contrôlables s’il existe un fort engagement des autorités locales. Les 55 arrêtés de biotope, et surtout les 154 sites Natura 2000 avec leurs plans de gestion associés, apparaissent comme des voies prometteuses pour mettre en œuvre ce type d’actions en France. Le cas de l’île Corse, récemment colonisée par O. limosus, mériterait des mesures réglementaires particulières pour éviter que P. leniusculus et P. clarkii, ne la suivent dans l’avenir.

  15. Banks Lake Fishery Evaluation Project Annual Report : Fiscal Year 2008 (March 1, 2008 to February 1, 2009).

    Energy Technology Data Exchange (ETDEWEB)

    Polacek, Matt [Washington Department of Fish and Wildlife

    2009-07-15

    The Washington Department of Fish and Wildlife implemented the Banks Lake Fishery Evaluation Project (BLFEP) in September 2001 with funds from the Bonneville Power Administration, and continued project tasks in 2008. The objective was to evaluate factors that could limit kokanee in Banks Lake, including water quality, prey availability, harvest, and acute predation during hatchery releases. Water quality parameters were collected twice monthly from March through November. Banks Lake water temperatures began to increase in May and stratification was apparent by July. By late August, the thermocline had dropped to 15 meters deep, with temperatures of 21-23 C in the epilimnion and 16-19 C in the hypolimnion. Dissolved oxygen levels were generally above 8 mg/L until August when they dropped near or below 5 mg/L deeper than 20-meters. Secchi depths ranged from 3.2 to 6.2 meters and varied spatially and temporally. Daphnia and copepod densities were the highest in May and June, reaching densities of 26 copepods/liter and 9 Daphnia/liter. Fish surveys were conducted in July and October 2008 using boat electrofishing, gill netting, and hydroacoustic surveys. Lake whitefish (71%) and yellow perch (16%) dominated the limnetic fish assemblage in the summer, while lake whitefish (46%) and walleye (22%) were the most abundant in gill net catch during the fall survey. Piscivore diets switched from crayfish prior to the release of rainbow trout to crayfish and rainbow trout following the release. The highest angling pressure occurred in May, when anglers were primarily targeting walleye and smallmouth bass. Boat anglers utilized Steamboat State Park more frequently than any other boat ramp on Banks Lake. Shore anglers used the rock jetty at Coulee City Park 45% of the time, with highest use occurring from November through April. Ice fishing occurred in January and February at the south end of the lake. An estimated total of 4,397 smallmouth bass, 11,106 walleye, 371 rainbow trout

  16. US cities can manage national hydrology and biodiversity using local infrastructure policy.

    Science.gov (United States)

    McManamay, Ryan A; Surendran Nair, Sujithkumar; DeRolph, Christopher R; Ruddell, Benjamin L; Morton, April M; Stewart, Robert N; Troia, Matthew J; Tran, Liem; Kim, Hyun; Bhaduri, Budhendra L

    2017-09-05

    Cities are concentrations of sociopolitical power and prime architects of land transformation, while also serving as consumption hubs of "hard" water and energy infrastructures. These infrastructures extend well outside metropolitan boundaries and impact distal river ecosystems. We used a comprehensive model to quantify the roles of anthropogenic stressors on hydrologic alteration and biodiversity in US streams and isolate the impacts stemming from hard infrastructure developments in cities. Across the contiguous United States, cities' hard infrastructures have significantly altered at least 7% of streams, which influence habitats for over 60% of North America's fish, mussel, and crayfish species. Additionally, city infrastructures have contributed to local extinctions in 260 species and currently influence 970 indigenous species, 27% of which are in jeopardy. We find that ecosystem impacts do not scale with city size but are instead proportionate to infrastructure decisions. For example, Atlanta's impacts by hard infrastructures extend across four major river basins, 12,500 stream km, and contribute to 100 local extinctions of aquatic species. In contrast, Las Vegas, a similar size city, impacts cities have local policy choices that can reduce future impacts to regional aquatic ecosystems as they grow. By coordinating policy and communication between hard infrastructure sectors, local city governments and utilities can directly improve environmental quality in a significant fraction of the nation's streams reaching far beyond their city boundaries.

  17. Don't be Half-Educated About Haff Disease in Louisiana.

    Science.gov (United States)

    Diaz, James

    2015-01-01

    Cases of Haff disease, a syndrome of severe myalgia and rhabdomyolysis, have been reported after eating cooked fish in Europe and the US. A retrospective review of US cases was conducted to identify seafood vectors, describe presenting manifestations, and compare the Haff disease toxidrome with other seafood-borne toxidromes. Internet search engines were queried to identify all US reports of Haff disease. The case definition of Haff disease required cooked seafood ingestion history within 24 hours and markedly elevated serum creatine kinase (CK) with CK-muscle/brain (MB) fraction baked salmon in North Carolina (n = 2). California and Louisiana accounted for most cases (n = 18, p = 0.012). Following mean incubation periods of eight hours; the most common presenting manifestations included vomiting, myalgia, muscle rigidity, chest pain mimicking myocardial infarction, diaphoresis, dyspnea, and brown urine indicating myoglobinuria. Most patients recovered within 2-5 days. Haff disease may follow the consumption of freshwater buffalo fish, freshwater crayfish, and saltwater Atlantic salmon. The bioconcentration of a new, unidentified heat-stable, freshwater and/or brackish/saltwater algal myotoxin in seafood, similar to palytoxin, is suspected of causing Haff disease. Experimental animals fed toxic buffalo fish developed rhabdomyolysis with myoglobinuria.

  18. Inactivation of Paragonimus westermani metacercariae in soy sauce-marinated and frozen freshwater crabs.

    Science.gov (United States)

    Kim, Tae Im; Oh, Se-Ra; Dai, Fuhong; Yang, Hyun-Jong; Ha, Sang-Do; Hong, Sung-Jong

    2017-03-01

    Soy sauce-marinated freshwater crabs (Eriocheir japonicus) are a source of human paragonimiasis. The viability of Paragonimus westermani metacercariae (PwMc) in marinated crabs was investigated in an experimental setting. The PwMc collected from freshwater crayfish were inoculated into freshwater crabs, which were then frozen or marinated in soy sauce. All PwMc in the freshwater crabs were inactivated after freezing for 48 h at -20 °C and after freezing for 12 h at -40 °C. After marinating for 32 days, the survival rate of PwMc in 5% NaCl soy sauce was 50%, in 7.5% NaCl soy sauce it was 33.3%, and in 10.0% NaCl soy sauce it was 31.3%. When marinated for 64 days, all PwMc were inactivated in all experimental groups. These results revealed that freezing and soy sauce marination were detrimental to the survival of PwMc in freshwater crabs. Specifically, freezing crabs for more than 48 h or soaking them in soy sauce containing at least 5.0% NaCl for 64 days can inactivate PwMc. These results can inform the production of the traditional Korean soy sauce-marinated freshwater crabs known as gejang.

  19. A TALE of shrimps: Genome-wide survey of homeobox genes in 120 species from diverse crustacean taxa [version 1; referees: 2 approved, 1 approved with reservations

    Directory of Open Access Journals (Sweden)

    Wai Hoong Chang

    2018-01-01

    Full Text Available The homeodomain-containing proteins are an important group of transcription factors found in most eukaryotes including animals, plants and fungi. Homeobox genes are responsible for a wide range of critical developmental and physiological processes, ranging from embryonic development, innate immune homeostasis to whole-body regeneration. With continued fascination on this key class of proteins by developmental and evolutionary biologists, multiple efforts have thus far focused on the identification and characterization of homeobox orthologs from key model organisms in attempts to infer their evolutionary origin and how this underpins the evolution of complex body plans. Despite their importance, the genetic complement of homeobox genes has yet been described in one of the most valuable groups of animals representing economically important food crops. With crustacean aquaculture being a growing industry worldwide, it is clear that systematic and cross-species identification of crustacean homeobox orthologs is necessary in order to harness this genetic circuitry for the improvement of aquaculture sustainability. Using publicly available transcriptome data sets, we identified a total of 4183 putative homeobox genes from 120 crustacean species that include food crop species, such as lobsters, shrimps, crayfish and crabs. Additionally, we identified 717 homeobox orthologs from 6 other non-crustacean arthropods, which include the scorpion, deer tick, mosquitoes and centipede. This high confidence set of homeobox genes will now serve as a key resource to the broader community for future functional and comparative genomics studies.

  20. Heavy Metals in Seafood and Farm Produce from Uyo, Nigeria; Levels and health implications

    Directory of Open Access Journals (Sweden)

    Orish E. Orisakwe

    2015-05-01

    Full Text Available Objectives: This study aimed to obtain representative data on the levels of heavy metals in seafood and farm produce consumed by the general population in Uyo, Akwa Ibom State, Nigeria, a region known for the exploration and exploitation of crude oil. Methods: In May 2012, 25 food items, including common types of seafood, cereals, root crops and vegetables, were purchased in Uyo or collected from farmland in the region. Dried samples were ground, digested and centrifuged. Levels of heavy metals (lead, cadmium, nickel, cobalt and chromium were analysed using an atomic absorption spectrophotometer. Average daily intake and target hazard quotients (THQ were estimated. Results: Eight food items (millet, maize, periwinkle, crayfish, stock fish, sabina fish, bonga fish and pumpkin leaf had THQ values over 1.0 for cadmium, indicating a potential health risk in their consumption. All other heavy metals had THQ values below 1.0, indicating insignificant health risks. The total THQ for the heavy metals ranged from 0.389 to 2.986. There were 14 items with total THQ values greater than 1.0, indicating potential health risks in their consumption. Conclusion: The regular consumption of certain types of farm produce and seafood available in Uyo, Akwa Ibom State, Nigeria, is likely adding to the body burden of heavy metals among those living in this region.

  1. Elements in fish of Malibu Creek and Malibu Lagoon near Los Angeles, California

    Energy Technology Data Exchange (ETDEWEB)

    Moeller, Anthony; MacNeil, Spencer D.; Ambrose, Richard F.; Que Hee, Shane S

    2003-04-01

    Our aim was to assess whether past discharges from a wastewater treatment plant increased metal pollutant loads in stream mobile species in a one-day baseline sampling study that included a coastal wetland. Mosquitofish (Gambusia affinis) of two sizes, black bullhead (Ameiurus melas), and crayfish (Pacifastacus leniusculus) were collected from Malibu Creek, and California killifish (Fundulus parvipinnis) of three sizes, as well as arroyo chub (Gila orcutti) were sampled from Malibu Lagoon near Los Angeles, California. Species from each locality were pooled by length, homogenized, digested by microwave wet ashing, and analyzed by simultaneous inductively coupled plasma atomic emission spectroscopy for 27 elements. Lagoon killifish 2.0-3.5 cm long contained levels of arsenic and lead above the levels for 95% of California fish, the EDL95. Black bullhead upstream of the discharge contained elevated levels of As, Cr and Se. Young mosquitofish <3 cm in length upstream of the discharge differed greatly in the order of abundance of their elements relative to larger mosquitofish and to other species collected. More sampling than this baseline study allowed was needed to determine if the wastewater treatment plant was a pollution source.

  2. Studying emotion in invertebrates: what has been done, what can be measured and what they can provide.

    Science.gov (United States)

    Perry, Clint J; Baciadonna, Luigi

    2017-11-01

    Until recently, whether invertebrates might exhibit emotions was unknown. This possibility has traditionally been dismissed by many as emotions are frequently defined with reference to human subjective experience, and invertebrates are often not considered to have the neural requirements for such sophisticated abilities. However, emotions are understood in humans and other vertebrates to be multifaceted brain states, comprising dissociable subjective, cognitive, behavioural and physiological components. In addition, accumulating literature is providing evidence of the impressive cognitive capacities and behavioural flexibility of invertebrates. Alongside these, within the past few years, a number of studies have adapted methods for assessing emotions in humans and other animals, to invertebrates, with intriguing results. Sea slugs, bees, crayfish, snails, crabs, flies and ants have all been shown to display various cognitive, behavioural and/or physiological phenomena that indicate internal states reminiscent of what we consider to be emotions. Given the limited neural architecture of many invertebrates, and the powerful tools available within invertebrate research, these results provide new opportunities for unveiling the neural mechanisms behind emotions and open new avenues towards the pharmacological manipulation of emotion and its genetic dissection, with advantages for disease research and therapeutic drug discovery. Here, we review the increasing evidence that invertebrates display some form of emotion, discuss the various methods used for assessing emotions in invertebrates and consider what can be garnered from further emotion research on invertebrates in terms of the evolution and underlying neural basis of emotion in a comparative context. © 2017. Published by The Company of Biologists Ltd.

  3. Standard Guide for Irradiation of Finfish and Aquatic Invertebrates Used as Food to Control Pathogens and Spoilage Microorganisms

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2009-01-01

    1.1 This guide outlines procedures and operations for the irradiation of raw, untreated, fresh (chilled), or frozen finfish and aquatic invertebrates, while ensuring that the irradiated product is safe and wholesome. 1.1.1 Aquatic invertebrates include molluscs, crustacea, echinoderms, etc. 1.1.1.1 Molluscs include bivalve shellfish, such as clams, mussels, and oysters; snails; and cephalopods, such as squid and octopus. 1.1.1.2 Crustacea include shellfish such as shrimp, lobster, crabs, prawns and crayfish. 1.1.1.3 Echinoderms include sea urchins and sea cucumbers. 1.2 This guide covers absorbed doses used to reduce the microbial and parasite populations in aquatic invertebrates and finfish. Such doses typically are below 10 kGy (1). 1.3 The use of reduced-oxygen packaging (vacuum or modified atmosphere, and including products packed in oil) with irradiated, raw product is not covered by this guide. The anaerobic environment created by reduced-oxygen packaging provides the potential for outgrowth o...

  4. A semi-automated method of monitoring dam passage of American Eels Anguilla rostrata

    Science.gov (United States)

    Welsh, Stuart A.; Aldinger, Joni L.

    2014-01-01

    Fish passage facilities at dams have become an important focus of fishery management in riverine systems. Given the personnel and travel costs associated with physical monitoring programs, automated or semi-automated systems are an attractive alternative for monitoring fish passage facilities. We designed and tested a semi-automated system for eel ladder monitoring at Millville Dam on the lower Shenandoah River, West Virginia. A motion-activated eel ladder camera (ELC) photographed each yellow-phase American Eel Anguilla rostrata that passed through the ladder. Digital images (with date and time stamps) of American Eels allowed for total daily counts and measurements of eel TL using photogrammetric methods with digital imaging software. We compared physical counts of American Eels with camera-based counts; TLs obtained with a measuring board were compared with TLs derived from photogrammetric methods. Data from the ELC were consistent with data obtained by physical methods, thus supporting the semi-automated camera system as a viable option for monitoring American Eel passage. Time stamps on digital images allowed for the documentation of eel passage time—data that were not obtainable from physical monitoring efforts. The ELC has application to eel ladder facilities but can also be used to monitor dam passage of other taxa, such as crayfishes, lampreys, and water snakes.

  5. Species- and habitat-specific bioaccumulation of total mercury and methylmercury in the food web of a deep oligotrophic lake.

    Science.gov (United States)

    Arcagni, Marina; Juncos, Romina; Rizzo, Andrea; Pavlin, Majda; Fajon, Vesna; Arribére, María A; Horvat, Milena; Ribeiro Guevara, Sergio

    2018-01-15

    Niche segregation between introduced and native fish in Lake Nahuel Huapi, a deep oligotrophic lake in Northwest Patagonia (Argentina), occurs through the consumption of different prey. Therefore, in this work we analyzed total mercury [THg] and methylmercury [MeHg] concentrations in top predator fish and in their main prey to test whether their feeding habits influence [Hg]. Results indicate that [THg] and [MeHg] varied by foraging habitat and they increased with greater percentage of benthic diet and decreased with pelagic diet in Lake Nahuel Huapi. This is consistent with the fact that the native creole perch, a mostly benthivorous feeder, which shares the highest trophic level of the food web with introduced salmonids, had higher [THg] and [MeHg] than the more pelagic feeder rainbow trout and bentho-pelagic feeder brown trout. This differential THg and MeHg bioaccumulation observed in native and introduced fish provides evidence to the hypothesis that there are two main Hg transfer pathways from the base of the food web to top predators: a pelagic pathway where Hg is transferred from water, through plankton (with Hg in inorganic species mostly), forage fish to salmonids, and a benthic pathway, as Hg is transferred from the sediments (where Hg methylation occurs mostly), through crayfish (with higher [MeHg] than plankton), to native fish, leading to one fold higher [Hg]. Copyright © 2017 Elsevier B.V. All rights reserved.

  6. Speciation and bioavailability of Americium-241 in the fresh water environment

    International Nuclear Information System (INIS)

    Bierkens, J.

    1986-01-01

    Due to its anthropogenic origin, the transuranic americium 241 confronts physiologists with the intriguing question, which mechanisms are involved in the incorporation or elimination of such artificial elements in biological cycles. The investigations on the speciation and bioavailability of 241 Am in the freshwater environment aim to establish a relation between the behavior of 241 Am in freshwater ecosystems and its availability for biota. In the limnic environment, most often characterized by a high organic load and a low conductivity, the effect of complexation of 241 Am with humic acids and competition with trivalent cations such as A1 and Fe, were proven to be significant on the speciation of 241 Am. Based on the registration of the 241 Am uptake by a large number of freshwater organisms, the crayfish Astacus leptodactylus Eschscholtz was chosen to study the whole-body uptake of 241 Am, its corresponding organ distribution and its retention in the animal. The share of external fixation and ingestion in the global uptake, and the effect of speciation on it, were studied more carefully. Other aspects in this physiological part were: the kinetics of 241 Am in the hemolymph and the hepatopancreas, and its subcellular distribution in the digestive gland. Finally, by comparing the physiology of 241 Am with some other metals ( 240 Pu, 64 Cu, 198 Au) with analogous or contradictional properties, we tried to find out whether the behavior of 241 Am in organisms can be explained from its chemical characteristics

  7. Effects of pond draining on biodiversity and water quality of farm ponds.

    Science.gov (United States)

    Usio, Nisikawa; Imada, Miho; Nakagawa, Megumi; Akasaka, Munemitsu; Takamura, Noriko

    2013-12-01

    Farm ponds have high conservation value because they contribute significantly to regional biodiversity and ecosystem services. In Japan pond draining is a traditional management method that is widely believed to improve water quality and eradicate invasive fish. In addition, fishing by means of pond draining has significant cultural value for local people, serving as a social event. However, there is a widespread belief that pond draining reduces freshwater biodiversity through the extirpation of aquatic animals, but scientific evaluation of the effectiveness of pond draining is lacking. We conducted a large-scale field study to evaluate the effects of pond draining on invasive animal control, water quality, and aquatic biodiversity relative to different pond-management practices, pond physicochemistry, and surrounding land use. The results of boosted regression-tree models and analyses of similarity showed that pond draining had little effect on invasive fish control, water quality, or aquatic biodiversity. Draining even facilitated the colonization of farm ponds by invasive red swamp crayfish (Procambarus clarkii), which in turn may have detrimental effects on the biodiversity and water quality of farm ponds. Our results highlight the need for reconsidering current pond management and developing management plans with respect to multifunctionality of such ponds. Efectos del Drenado de Estanques sobre la Biodiversidad y la Calidad del Agua en Estanques de Cultivo. © 2013 Society for Conservation Biology.

  8. A new photosensory function for simple photoreceptors, the intrinsically photoresponsive neurons of the sea slug Onchidium

    Directory of Open Access Journals (Sweden)

    Tsukasa Gotow

    2009-12-01

    Full Text Available Simple photoreceptors, namely intrinsically light-sensitive neurons without microvilli and/or cilia, have long been known to exist in the central ganglia of crayfish, Aplysia, Onchidium, and Helix. These simple photoreceptors are not only first-order photosensory cells, but also second-order neurons (interneurons, relaying several kinds of sensory synaptic inputs. Another important issue is that the photoresponses of these simple photoreceptors show very slow kinetics and little adaptation. These characteristics suggest that the simple photoreceptors of the Onchidium have a function in non-image-forming vision, different from classical eye photoreceptors used for cording dynamic images of vision. The cited literature provides evidence that the depolarizing and hyperpolarizing photoresponses of simple photoreceptors play a role in the long-lasting potentiation of synaptic transmission of excitatory and inhibitory sensory inputs, and as well as in the potentiation and the suppression of the subsequent behavioral outputs. In short, we suggest that simple photoreceptors operate in the general potentiation of synaptic transmission and subsequent motor output; i.e., they perform a new photosensory function.

  9. Biota-sediment accumulation factors for radionuclides and sediment associated biota of the Ottawa River

    Energy Technology Data Exchange (ETDEWEB)

    Rowan, D.; Silke, R.; Carr, J., E-mail: rowand@aecl.ca [Atomic Energy of Canada Limited, Chalk River, Ontario (Canada)

    2013-12-15

    As Ottawa River contamination is historical and resides in sediment, ecological risk and trophic transfer depend on linkages between sediment and biota. One of the ways in which this linkage is quantified is through the use of the biota sediment accumulation factor (BSAF). In this study, we present the first field estimates of BSAF for a number of radionuclides. The strongest and most consistent BSAFs were those for {sup 137}Cs in deposit feeding taxa, suggesting that sediment concentrations rather than dissolved concentrations drive uptake. For crayfish and unionid bivalves that do not feed on sediment, biota radionuclide concentrations were not related to sediment concentrations, but rather reflected concentrations in water. BSAFs would not be appropriate for these non-deposit feeding biota. BSAFs for {sup 137}Cs were not significantly different among deposit feeding taxa, suggesting similar processes for ingestion, assimilation and elimination. These data also show that the concentration factor approach used for guidance would have led to spurious results in this study for deposit feeding benthic invertebrates. Concentrations of {sup 137}Cs in Hexagenia downstream of the CRL process outfall range by about 2-orders of magnitude, in comparison to relatively uniform water concentrations. The concentration factor approach would have predicted a single value downstream of CRL, underestimating exposure to Hexagenia by almost 2-orders of magnitude at sites close to the CRL process outfall. (author)

  10. 'Different strokes for different folks': geographically isolated strains of Lymnaea stagnalis only respond to sympatric predators and have different memory forming capabilities.

    Science.gov (United States)

    Orr, Michael V; Hittel, Karla; Lukowiak, Ken

    2009-07-01

    Gaining insight into how natural trait variation is manifest in populations shaped by differential environmental factors is crucial to understanding the evolution, ecology and sensory biology of natural populations. We have demonstrated that lab-reared Lymnaea detect and respond to the scent of a crayfish predator with specific, appropriate anti-predator behavioral responses, including enhanced long-term memory (LTM) formation, and that such predator detection significantly alters the electrophysiological activity of RPeD1, a neuron that is a necessary site for LTM formation. Here we ask: (1) do distinct populations of wild Lymnaea stagnalis respond only to sympatric predators and if so, can these traits be quantified at both the behavioral and neurophysiological levels, and (2) does the presence of a non-sympatric predator elicit anti-predator behaviors including augmentation of LTM? We tested three different populations of wild (i.e. not lab-reared) snails freshly collected from their natural habitat: (1) polders near Utrecht in The Netherlands, (2) six seasonally isolated ponds in the Belly River drainage in southern Alberta, Canada and (3) a 20-year-old human-made dugout pond in southern Alberta. We found strain-specific variations in the ability to form LTM and that only a sympatric predator evoked anti-predatory behaviors, including enhanced LTM formation and changes in RPeD1 activity.

  11. Training Lymnaea in the presence of a predator scent results in a long-lasting ability to form enhanced long-term memory.

    Science.gov (United States)

    Forest, Jeremy; Sunada, Hiroshi; Dodd, Shawn; Lukowiak, Ken

    2016-06-01

    Lymnaea exposed to crayfish effluent (CE) gain an enhanced ability to form long-term memory (LTM). We test the hypothesis that a single CE exposure and operant conditioning training leads to long lasting changes in the capability of snails to form LTM when tested in pond water four weeks later. We trained both juvenile and adult snails with a single 0.5 h training session in CE and show that LTM was present 24 h later. Snails trained in a similar manner in just pond water show no LTM. We then asked if such training in CE conferred enhanced memory forming capabilities on these snails four weeks later. That is, would LTM be formed in these snails four weeks later following a single 0.5 h training session in pond water? We found that both adult and juvenile snails previously trained in CE one month previously had enhanced LTM formation abilities. The injection of a DNA methylation blocker, 5-AZA, prior to training in adult snails blocked enhanced LTM formation four weeks later. Finally, this enhanced LTM forming ability was not passed on to the next generation of snails.

  12. A TALE of shrimps: Genome-wide survey of homeobox genes in 120 species from diverse crustacean taxa.

    Science.gov (United States)

    Chang, Wai Hoong; Lai, Alvina G

    2018-01-01

    The homeodomain-containing proteins are an important group of transcription factors found in most eukaryotes including animals, plants and fungi. Homeobox genes are responsible for a wide range of critical developmental and physiological processes, ranging from embryonic development, innate immune homeostasis to whole-body regeneration. With continued fascination on this key class of proteins by developmental and evolutionary biologists, multiple efforts have thus far focused on the identification and characterization of homeobox orthologs from key model organisms in attempts to infer their evolutionary origin and how this underpins the evolution of complex body plans. Despite their importance, the genetic complement of homeobox genes has yet been described in one of the most valuable groups of animals representing economically important food crops. With crustacean aquaculture being a growing industry worldwide, it is clear that systematic and cross-species identification of crustacean homeobox orthologs is necessary in order to harness this genetic circuitry for the improvement of aquaculture sustainability. Using publicly available transcriptome data sets, we identified a total of 4183 putative homeobox genes from 120 crustacean species that include food crop species, such as lobsters, shrimps, crayfish and crabs. Additionally, we identified 717 homeobox orthologs from 6 other non-crustacean arthropods, which include the scorpion, deer tick, mosquitoes and centipede. This high confidence set of homeobox genes will now serve as a key resource to the broader community for future functional and comparative genomics studies.

  13. Diet of otters (Lutra lutra in various habitat types in the Pannonian biogeographical region compared to other regions of Europe

    Directory of Open Access Journals (Sweden)

    József Lanszki

    2016-08-01

    Full Text Available Knowledge of the effect of habitat type and region on diet and feeding behaviours of a species facilitates a better understanding of factors impacting populations, which contributes to effective conservation management. Using spraint analysis and relative frequency of occurrence data from the literature, we described the dietary patterns of Eurasian otters (Lutra lutra in 23 study sites within the Pannonian biogeographical region in Hungary. Our results indicated that diet composition varied by habitat type and is therefore context dependant. The differences among habitat types were however lower than expected. We noticed a decline in the fish consumption with a concomitant increase in trophic niche breadth and amphibian consumption in rivers, ponds (fish farms, backwaters, marshes and small watercourses. The main differences in diet were not attributed to the consumption of primary and secondary food types (fish and amphibians, but rather to differences in other, less important food types (mammals, birds. Using hierarchical cluster analysis, rivers and ponds could clearly be separated from other habitat types. We found the main fish diet of otters in most of these areas consisted of small (<100 g, eurytopic, littoral and non-native, mostly invasive species. Dietary studies from 91 sites in six European biogeographical regions showed that fish are consumed most frequently in the Atlantic and Boreal, less in the Continental and Pannonian, and least in the Alpine and Mediterranean regions. Comparative analysis indicated that the Mediterranean region (with frequent crayfish consumption and Alpine region (frequent amphibian consumption cluster separate from the other regions.

  14. The B vitamins nicotinamide (B3) and riboflavin (B2) stimulate metamorphosis in larvae of the deposit-feeding polychaete Capitella teleta: implications for a sensory ligand-gated ion channel.

    Science.gov (United States)

    Burns, Robert T; Pechenik, Jan A; Biggers, William J; Scavo, Gia; Lehman, Christopher

    2014-01-01

    Marine sediments can contain B vitamins, presumably incorporated from settled, decaying phytoplankton and microorganisms associated with decomposition. Because B vitamins may be advantageous for the energetically intensive processes of metamorphosis, post-metamorphic growth, and reproduction, we tested several B vitamins to determine if they would stimulate larvae of the deposit-feeding polychaete Capitella teleta to settle and metamorphose. Nicotinamide and riboflavin individually stimulated larvae of C. teleta to settle and metamorphose, generally within 1-2 hours at nicotinamide concentrations as low as 3 µM and riboflavin concentrations as low as 50 µM. More than 80% of the larvae metamorphosed within 30 minutes at a nicotinamide concentration of 7 µM. The pyridine channel agonist pyrazinecarboxamide also stimulated metamorphosis at very low concentrations. In contrast, neither lumichrome, thiamine HCl, pyridoxine HCl, nor vitamin B12 stimulated larvae of C. teleta to metamorphose at concentrations as high as 500 µM. Larvae also did not metamorphose in response to either nicotinamide or pyrazinecarboxamide in calcium-free seawater or with the addition of 4-acetylpyridine, a competitive inhibitor of the pyridine receptor. Together, these results suggest that larvae of C. teleta are responding to nicotinamide and riboflavin via a chemosensory pyridine receptor similar to that previously reported to be present on crayfish chela and involved with food recognition. Our data are the first to implicate B vitamins as possible natural chemical settlement cues for marine invertebrate larvae.

  15. Environmental radiological studies downstream from the Rancho Seco Nuclear Power Generating Station, 1985

    International Nuclear Information System (INIS)

    Noshkin, V.E.; Wong, K.M.; Eagle, R.J.; Brunk, J.L.; Jokela, T.A.

    1986-01-01

    Information compiled in 1985 while assessing the environmental impact of radionuclides previously discharged with aqueous releases from the Rancho Seco Nuclear Power Generating Plant is presented. In October 1984, the quantities of gamma-emitting radionuclides in water discharged to Clay Creek from the plant were reduced below operationally defined detection limits for liquid effluents. However, radionuclides previously discharged persist in the downstream environment and are found in many aquatic dietary components. 134 Cs and 137 Cs are the primary gamma-emitting radionuclides detected in the edible flesh of different fish, crayfish, and frogs. Coefficients for exponential equations are generated, from a least square analysis, that relate the change in concentration of 137 Cs in fish to distance downstream and time between March and October 1985. Concentrations of 137 Cs in surface creek sediments also decreased in the downstream direction much in the same manner as concentrations decreased in fish. However, there was no significant difference in the radiocesium concentrations in surface sediements collected from comparable locations during both 1984 and 1985

  16. Historical freshwater fish ecology: a long-term view of distribution changes and biological invasions

    Directory of Open Access Journals (Sweden)

    Miguel Clavero

    2015-12-01

    Full Text Available Past processes and events may have an important influence on contemporaneous ecological patterns, including current human impacts on landscapes and organisms. In spite of that, most of the ecological knowledge has been built upon short-term studies, which very rarely exceed one decade. Ecology and Conservation Biology have an important lack of historical approaches, a deficiency that may become a hindrance for the management of natural systems. In this talk I will present examples of how historical information on the distribution of freshwater fish and other aquatic organisms can be used to address ecological questions. Most analyses are based on two important Spanish historical written sources: the Relaciones de Felipe II (16th century and the Madoz Dictionary (19th century. The examples considered include the European eel (Anguilla anguilla, the brown trout (Salmo trutta, the common carp (Cyprinus carpio and the white clawed crayfish (Austropotamobius italicus, among other species, as well as questions related to biological invasions, habitat loss and the impacts of global warming. The outputs of ecological research based on historical data often become useful tools for present-day biodiversity conservation planning and actions.

  17. Ecotoxicological impact of Zequanox®, a novel biocide, on selected non-target Irish aquatic species.

    Science.gov (United States)

    Meehan, Sara; Shannon, Adam; Gruber, Bridget; Rackl, Sarahann M; Lucy, Frances E

    2014-09-01

    Effective, species-specific zebra mussel control is needed urgently for Ireland׳s freshwater bodies, which became infested with non-native zebra mussels in the 1990s. Zequanox®, a newly commercialized product for zebra and quagga mussel control, is composed of dead Pseudomonas fluorescens CL 145A cells. This paper describes ecotoxicology tests on three representative native Irish freshwater species: Anodonta (duck mussel), Chironomus plumosus (non-biting midge), and Austropotamobius pallipes (white-clawed crayfish). The species were exposed to Zequanox in a 72-h static renewal toxicity test at concentrations of 100-750mg active ingredient per liter (mga.i./L). Water quality parameters were measured every 12-24h before and after water and product renewal. After 72h, endpoints were reported as LC10, LC50, and LC100. The LC50 values derived were (1) Anodonta: ≥500mga.i./L (2) C. plumosus: 1075mga.i./L, and (3) A. pallipes: ≥750mga.i./L. These results demonstrate that Zequanox does not negatively affect these organisms at the concentration required for >80percent zebra mussel mortality (150mg a.i/L) and the maximum allowable treatment concentration in the United Sates (200mga.i./L). They also show the overall species-specificity of Zequanox, and support its use in commercial facilities and open waters. Copyright © 2014 Elsevier Inc. All rights reserved.

  18. Isparta Gülünün (Rosa damascena Mill. Su Ürünlerinde Gıda Katkı Maddesi Olarak Kullanımı: Antimikrobiyel ve Antioksidan Özellikleri Açısından Genel Değerlendirme

    Directory of Open Access Journals (Sweden)

    Abdullah DİLER

    2014-07-01

    Full Text Available Rose species have significant place among ornemantal flowers. Nowadays, the members of the family of Rosaceae are used in foods and for medical purposes. The members of this family have significant physiological functions due to their phenolic compounds richness (citronellol, graniol and nerol. Phenolic compounds acts as antioxidant, free radical scvenger, anti-cancer, anti-inflammatory, anti-mutegenic, anti-depresant and antibacterial. Fresh sea foods have relatively short shelf-life. In this context economical loses could be raised and increased losses could be in long distences. Nowadays, essential oils are used in processing technologies. Frequently used essential oils in sea foods are thyme, laurel, apple, clove and generally used as antioxidant and antimicrobial additives. The favorable results were presented in the literature in terms of usage of the essential oils as antibacterial agent against food pathogens. Additionally, decelerated lipid oxidation in the case of usage of essentials oils compared to synthetical antioxidants. Isparta has significant place in terms of the production of fresh water fish (carp, rainbow trout, and pike perch and crayfish. Fresh water fish are generally marketed fresh for the consumption. Even though there is no available information about the usage of rose extract in sea foods, by taking into

  19. US cities can manage national hydrology and biodiversity using local infrastructure policy

    Science.gov (United States)

    Surendran Nair, Sujithkumar; DeRolph, Christopher R.; Ruddell, Benjamin L.; Morton, April M.; Stewart, Robert N.; Troia, Matthew J.; Tran, Liem; Kim, Hyun; Bhaduri, Budhendra L.

    2017-01-01

    Cities are concentrations of sociopolitical power and prime architects of land transformation, while also serving as consumption hubs of “hard” water and energy infrastructures. These infrastructures extend well outside metropolitan boundaries and impact distal river ecosystems. We used a comprehensive model to quantify the roles of anthropogenic stressors on hydrologic alteration and biodiversity in US streams and isolate the impacts stemming from hard infrastructure developments in cities. Across the contiguous United States, cities’ hard infrastructures have significantly altered at least 7% of streams, which influence habitats for over 60% of North America’s fish, mussel, and crayfish species. Additionally, city infrastructures have contributed to local extinctions in 260 species and currently influence 970 indigenous species, 27% of which are in jeopardy. We find that ecosystem impacts do not scale with city size but are instead proportionate to infrastructure decisions. For example, Atlanta’s impacts by hard infrastructures extend across four major river basins, 12,500 stream km, and contribute to 100 local extinctions of aquatic species. In contrast, Las Vegas, a similar size city, impacts impacts to regional aquatic ecosystems as they grow. By coordinating policy and communication between hard infrastructure sectors, local city governments and utilities can directly improve environmental quality in a significant fraction of the nation’s streams reaching far beyond their city boundaries. PMID:28827332

  20. Spiking Neural Networks Based on OxRAM Synapses for Real-Time Unsupervised Spike Sorting.

    Science.gov (United States)

    Werner, Thilo; Vianello, Elisa; Bichler, Olivier; Garbin, Daniele; Cattaert, Daniel; Yvert, Blaise; De Salvo, Barbara; Perniola, Luca

    2016-01-01

    In this paper, we present an alternative approach to perform spike sorting of complex brain signals based on spiking neural networks (SNN). The proposed architecture is suitable for hardware implementation by using resistive random access memory (RRAM) technology for the implementation of synapses whose low latency (spike sorting. This offers promising advantages to conventional spike sorting techniques for brain-computer interfaces (BCI) and neural prosthesis applications. Moreover, the ultra-low power consumption of the RRAM synapses of the spiking neural network (nW range) may enable the design of autonomous implantable devices for rehabilitation purposes. We demonstrate an original methodology to use Oxide based RRAM (OxRAM) as easy to program and low energy (Spike Timing Dependent Plasticity. Real spiking data have been recorded both intra- and extracellularly from an in-vitro preparation of the Crayfish sensory-motor system and used for validation of the proposed OxRAM based SNN. This artificial SNN is able to identify, learn, recognize and distinguish between different spike shapes in the input signal with a recognition rate about 90% without any supervision.

  1. Molecular evidence for high frequency of multiple paternity in a freshwater shrimp species Caridina ensifera.

    Directory of Open Access Journals (Sweden)

    Gen Hua Yue

    2010-09-01

    Full Text Available Molecular genetic analyses of parentage provide insights into mating systems. Although there are 22,000 members in Malacostraca, not much has been known about mating systems in Malacostraca. The freshwater shrimp Caridina ensifera blue, is a new species belonging to Malacostraca which was discovered recently in Sulawesi, Indonesia. Due to its small body size and low fecundity, this species is an ideal species to study the occurrence and frequency of multiple paternity and to understand of how the low fecundity species persist and evolve.In this study, we developed four polymorphic microsatellites from C. ensifera and applied them to investigate the occurrence and frequency of multiple paternity in 20 C. ensifera broods caught from Lake Matano, Sulawesi. By genotyping the mother and all offspring from each brood we discovered multiple paternity in all 20 broods. In most of the 20 broods, fathers contributed skewed numbers of offspring and there was an apparent inverse correlation between reproductive success of sires and their relatedness to mothers.Our results in combination with recent reports on multiple paternity in crayfish, crab and lobster species suggests that multiple paternity is common in Malacostraca. Skewed contribution of fathers to the numbers of offspring and inverse correlation between reproductive success of sires and their relatedness to mothers suggest that sperm competition occurred and/or pre- and postcopulatory female choice happen, which may be important for avoiding the occurrence of inbreeding and optimize genetic variation in offspring and for persistence and evolution of low fecundity species.

  2. Keanekaragaman dan Potensi Lobster (Malacostraca: Palinuridae di Pantai Pameungpeuk, Garut Selatan, Jawa Barat

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    Rianta Pratiwi

    2018-01-01

    Full Text Available Coral shrimp (Panulirus spp. or known as lobster is a potential fishery commodity and economic value. The demand for domestic and export market continues to increase both as local consumption and export. Indonesia is the largest lobster fishery producer in almost all Indonesian waters, from the west coast of Sumatra to the east coast Jayapura, one of which is Pameungpeuk beach, South Garut, West Java. As a result of increasing demand, fishermen try to catch as many lobsters and the impact of lobster prices also in creases and whereas fishermen continuously take it from nature. This study was conducted to determine the diversity and potential of lobster species especially living in high wavy waters along the southern coast of Garut (Pamengpeuk, West Java.The results of observation are only three types of crayfish, namely: a. Panulirus homarus (green lobster sand; b. Panulirus longipes (lobster flower/ red lobster and Panulirus versicolor (green lobster/bamboo; is most commonly found in the area of south Garut, Pameungpeuk beach with high and strong waves. The percentage of female P longipes species (42.88% was higher compared to male P. homarus (40% and ovigerous female of P. versicolor (37.14%. While the sexual ratio between P. homarus (1:2.0:2.0; P. longipes (1:1.2:1.0 and P. versicolor: 1:1.2:1.2  which statistically showed significantly different p <0.05.

  3. Fast calcium transients translate the distribution and conduction of neural activity in different regions of a single sensory neuron.

    Science.gov (United States)

    Purali, Nuhan

    2017-09-01

    In the present study, cytosolic calcium concentration changes were recorded in response to various forms of excitations, using the fluorescent calcium indicator dye OG-BAPTA1 together with the current or voltage clamp methods in stretch receptor neurons of crayfish. A single action potential evoked a rise in the resting calcium level in the axon and axonal hillock, whereas an impulse train or a large saturating current injection would be required to evoke an equivalent response in the dendrite region. Under voltage clamp conditions, amplitude differences between axon and dendrite responses vanished completely. The fast activation time and the modulation of the response by extracellular calcium concentration changes indicated that the evoked calcium transients might be mediated by calcium entry into the cytosol through a voltage-gated calcium channel. The decay of the responses was slow and sensitive to extracellular sodium and calcium concentrations as well as exposure to 1-10 mM NiCl 2 and 10-500 µM lanthanum. Thus, a sodium calcium exchanger and a calcium ATPase might be responsible for calcium extrusion from the cytosol. Present results indicate that the calcium indicator OG-BAPTA1 might be an efficient but indirect way of monitoring regional membrane potential differences in a single neuron.

  4. Fast Real-Time PCR for the Detection of Crustacean Allergens in Foods.

    Science.gov (United States)

    Santaclara, Francisco J; Espiñeira, Montserrat

    2017-01-01

    Crustaceans are one of the most common allergens causing severe food reaction. Hypersensitivity reactions associated with seafood intake are one of the most common food allergies in adults. Crustaceans including shrimps, prawns, crabs, lobster, and crayfish are a common cause of anaphylaxis or hypersensitivity, with shrimps and crabs being the most common causes of allergy. Symptoms occur most often when food or cooking water are ingested.These food allergens are a health problem, and they have become very important; as evidenced by the existence of several regulations that establish that labeling must be present regarding these allergens to warn consumers.The methodology herein exposed allows the detection of crustaceans in any type of product, including those where very aggressive treatments of temperature and pressure are used during the manufacturing process.The main features of this method are its high sensitivity and specificity, and reduced analysis time of real-time PCR (40 min). This assay is a potential tool in issues related to the labeling of products and food security to protect the allergic consumer.

  5. Deep insight into white spot syndrome virus vaccines: A review

    Directory of Open Access Journals (Sweden)

    MA Badhul Haq

    2012-02-01

    Full Text Available White spot syndrome virus (WSSV, the causative virus of the disease, is found in most shrimp farming areas of the world, where it causes large economic losses to the shrimp farming industry. The potentially fatal virus has been found to be a threat not only to all shrimp species, but also to other marine and freshwater crustaceans, such as crab and crayfish. To date, no effective prophylactic treatment measures are available for viral infections in shrimp and other crustaceans. Due to current aquaculture practices and the broad host range of WSSV, intervention strategies including vaccination against this virus would be pivotal to save and protect shrimp farming. Several achievements have been attained in the search of novel vaccines for WSSV. DNA vaccination, recombinant vaccines, oral vaccination techniques and gene therapy are some of the thrust areas of focus for scientists and researchers. This review article highlights the recent trends in the development of WSSV vaccines either as DNA vaccines or recombinant vaccines and their functioning strategies as suggested by the researchers worldwide.

  6. Paragonimiasis: A case report

    Energy Technology Data Exchange (ETDEWEB)

    Jeon, Kyung Hyeo; Park, Mi Jung; Bae, Kyung Soo; Choi, Hae Young; Choi, Ho Cheol; Na, Jae Boem; Choi, Dae Seob; Kim, Ho Cheol; Jang, In Seok; Kim, Dong Chul [Gyeongsang National University Hospital, Gyeongsang National University School of Medicine, Jinju (Korea, Republic of)

    2013-11-15

    Pleuropulmonary paragonimiasis is a parasitic infection caused by lung flukes including Paragonimus westermani. Paragonimiasis usually occurs from ingestion of raw or improperly cooked freshwater crabs or crayfish. Pleural or lung parenchymal lesions are commonly found on CT or chest radiographs, and radiologic manifestations of pleuropulmonary paragonimiasis vary with the stage of the disease. Early findings include pneumothorax or hydrothorax, focal air-space consolidation, and linear opacities. Later findings include thin-walled cysts, mass-like consolidation, nodules, or bronchiectasis. Pulmonary paragonimiasis often can be mistaken for pulmonary tuberculosis in tuberculosis-endemic areas or lung cancer when it presents as a solitary pulmonary nodule. Intraperitoneal or ectopic lesions such as those in the retroperitoneum can form during migration of a juvenile worm from the small intestine to the lungs. Although the symptoms and signs of pulmonary paragonimiasis are nonspecific, an early diagnosis can be made if radiologists understand the pathogenesis and typical imaging findings of the disease. The purpose of this report was to demonstrate the various imaging findings of pleuropulmonary paragonimiasis and to review articles to help radiologists make a proper diagnosis.

  7. Conservation status of freshwater gastropods of Canada and the United States

    Science.gov (United States)

    Johnson, Paul D.; Bogan, Arthur E.; Brown, Kenneth M.; Burkhead, Noel M.; Cordeiro, James R.; Garner, Jeffrey T.; Hartfield, Paul D.; Lepitzki, Dwayne A.; Mackie, Gerry L.; Pip, Eva; Tarpley, Thomas A.; Tiemann, Jeremy S.; Whelan, Nathan V.; Strong, Ellen E.

    2013-01-01

    This is the first American Fisheries Society conservation assessment of freshwater gastropods (snails) from Canada and the United States by the Gastropod Subcommittee (Endangered Species Committee). This review covers 703 species representing 16 families and 93 genera, of which 67 species are considered extinct, or possibly extinct, 278 are endangered, 102 are threatened, 73 are vulnerable, 157 are currently stable, and 26 species have uncertain taxonomic status. Of the entire fauna, 74% of gastropods are imperiled (vulnerable, threatened, endangered) or extinct, which exceeds imperilment levels in fishes (39%) and crayfishes (48%) but is similar to that of mussels (72%). Comparison of modern to background extinction rates reveals that gastropods have the highest modern extinction rate yet observed, 9,539 times greater than background rates. Gastropods are highly susceptible to habitat loss and degradation, particularly narrow endemics restricted to a single spring or short stream reaches. Compilation of this review was hampered by a paucity of current distributional information and taxonomic uncertainties. Although research on several fronts including basic biology, physiology, conservation strategies, life history, and ecology are needed, systematics and curation of museum collections and databases coupled with comprehensive status surveys (geographic limits, threat identification) are priorities.

  8. Dietary specifications reflect the feeding behaviour of the European otter (Lutra lutra in “Strandzha” Natural Park (Bulgaria

    Directory of Open Access Journals (Sweden)

    Natchev Nikolay

    2015-12-01

    Full Text Available Within the scope of the present study a field survey in the area of “Strandzha” Natural Park in south-east Bulgaria was carried out. The main goal of the investigation was to gain more detailed information on the diet of the European otters (Lutra lutra that inhabit the park. As indicators for the presence of the mustelids a set of standard procedures, such as footprints tracking and inspecting the terrain for otter spraints were used. A total of 204 excrements were found, measured, documented and then disintegrated in water. The food rests in the faeces were investigated and the diet of the local population was documented. On the base of the results we separated the excrements into six groups and analysed the relations between the contents of the spraints and the characteristics of the habitat where they were found. We discovered a clear tendency toward piscivory in the middle and down streams of the studied rivers in the Natural Park. In the upper streams, otters relied almost exclusively on invertebrates like bivalves and crayfish as food source. The fact, that even suboptimal habitats, which offered invariable menu, were exploited by the otters is an indication for the stability of the local population.

  9. Elements in fish of Malibu Creek and Malibu Lagoon near Los Angeles, California

    International Nuclear Information System (INIS)

    Moeller, Anthony; MacNeil, Spencer D.; Ambrose, Richard F.; Que Hee, Shane S.

    2003-01-01

    Our aim was to assess whether past discharges from a wastewater treatment plant increased metal pollutant loads in stream mobile species in a one-day baseline sampling study that included a coastal wetland. Mosquitofish (Gambusia affinis) of two sizes, black bullhead (Ameiurus melas), and crayfish (Pacifastacus leniusculus) were collected from Malibu Creek, and California killifish (Fundulus parvipinnis) of three sizes, as well as arroyo chub (Gila orcutti) were sampled from Malibu Lagoon near Los Angeles, California. Species from each locality were pooled by length, homogenized, digested by microwave wet ashing, and analyzed by simultaneous inductively coupled plasma atomic emission spectroscopy for 27 elements. Lagoon killifish 2.0-3.5 cm long contained levels of arsenic and lead above the levels for 95% of California fish, the EDL95. Black bullhead upstream of the discharge contained elevated levels of As, Cr and Se. Young mosquitofish <3 cm in length upstream of the discharge differed greatly in the order of abundance of their elements relative to larger mosquitofish and to other species collected. More sampling than this baseline study allowed was needed to determine if the wastewater treatment plant was a pollution source

  10. The combined use of chemical and biochemical markers to assess water quality in two low-stream rivers (NE Spain)

    International Nuclear Information System (INIS)

    Fernandes, Denise; Potrykus, Joanna; Morsiani, Cinzia; Raldua, Demetrio; Lavado, Ramon; Porte, Cinta

    2002-01-01

    Carps (Cyprinus carpio) and red swamp crayfish (Procambarus clarkii) were sampled from two low- stream Mediterranean rivers (Anoia and Cardener) receiving extensive urban and industrial waste water discharges. Tissue residues of selected pollutants (organo chlorinated compounds, polycyclic aromatic hydrocarbons (PAHs)) were determined in conjunction with different biochemical responses (cytochrome P450, phase II enzymes) with the aim of investigating whether resident organisms were responsive to changes in water quality. Biota inhabiting those rivers were highly exposed to complex mixtures of polychlorobiphenyls and dichlorodiphenyltrichloroethanes (up to 9 ng/g w.w.) and PAHs (up to 6097 ng/g of hydroxylated PAHs in bile), the highest residues being observed in carps from Cardener. This has a reflection n 7-ethoxyresorufin O-deethylase (EROD) activity; that in carps from ardener ranged between 350 and 550 pmol/min/mg protein, whereas in carps from Anoia ranged between was 90 and 250 pmol/min/mg protein. The highest activity recorded was downstream of the sewage treatment plants in both rivers. Phase II enzymes were less sensitive to pollutant exposure than EROD; nonetheless, both glutathione S-transferase and UDP-glucuronyl transferase ere higher in carps from Cardener. The results support the usefulness of the combined use of chemical and biochemical responses to assess and diagnose pollution in highly stressed ecosystems

  11. The B Vitamins Nicotinamide (B3) and Riboflavin (B2) Stimulate Metamorphosis in Larvae of the Deposit-Feeding Polychaete Capitella teleta: Implications for a Sensory Ligand-Gated Ion Channel

    Science.gov (United States)

    Burns, Robert T.; Pechenik, Jan A.; Biggers, William J.; Scavo, Gia; Lehman, Christopher

    2014-01-01

    Marine sediments can contain B vitamins, presumably incorporated from settled, decaying phytoplankton and microorganisms associated with decomposition. Because B vitamins may be advantageous for the energetically intensive processes of metamorphosis, post-metamorphic growth, and reproduction, we tested several B vitamins to determine if they would stimulate larvae of the deposit-feeding polychaete Capitella teleta to settle and metamorphose. Nicotinamide and riboflavin individually stimulated larvae of C. teleta to settle and metamorphose, generally within 1–2 hours at nicotinamide concentrations as low as 3 µM and riboflavin concentrations as low as 50 µM. More than 80% of the larvae metamorphosed within 30 minutes at a nicotinamide concentration of 7 µM. The pyridine channel agonist pyrazinecarboxamide also stimulated metamorphosis at very low concentrations. In contrast, neither lumichrome, thiamine HCl, pyridoxine HCl, nor vitamin B12 stimulated larvae of C. teleta to metamorphose at concentrations as high as 500 µM. Larvae also did not metamorphose in response to either nicotinamide or pyrazinecarboxamide in calcium-free seawater or with the addition of 4-acetylpyridine, a competitive inhibitor of the pyridine receptor. Together, these results suggest that larvae of C. teleta are responding to nicotinamide and riboflavin via a chemosensory pyridine receptor similar to that previously reported to be present on crayfish chela and involved with food recognition. Our data are the first to implicate B vitamins as possible natural chemical settlement cues for marine invertebrate larvae. PMID:25390040

  12. Twenty-five-year study of radionuclides in the Susquehanna river via periphyton biomonitors.

    Science.gov (United States)

    Patrick, Ruth; Palms, John; Kreeger, Danielle; Harris, Charles

    2007-01-01

    This 25-y study monitored aquatic and terrestrial gamma-ray-emitting radionuclide levels near a nuclear power plant. It is the only known, long-term environmental survey of its kind. It was conducted neither by a utility owner, nor by a government agency, but rather by a private, environmental research institution. Compared to dozens of other flora and fauna, periphyton was found to be the best indicator to biomonitor the Susquehanna River, which runs near PPL Susquehanna's nuclear plant. Sampling began in 1979 before the first plant start-up and continued for the next 24 years. Monitoring began two months after the Three Mile Island accident of 28 March 1979 and includes Three Mile Island area measurements. Ongoing measurements detected fallout from Chernobyl in 1986, as well as I not released from PPL Susquehanna. Although this paper concentrates on radionuclides found in periphyton, the scope of the entire environmental program includes a wide variety of aquatic and land-based plants, animals, and inorganic matter. Other species and matter studied were fish, mussels, snails, crayfish, insects, humus, mushrooms, lichens, squirrels, deer, cabbage, tomatoes, coarse and flocculated sediment, and more. Results show periphyton works well for detection of radionuclide activity, even in concentrations less than 100 Bq kg (picocuries per gram amounts). Data indicate that PPL Susquehanna's radionuclide releases have had no known environmental or human health impact.

  13. Variations in interpulse interval of double action potentials during propagation in single neurons.

    Science.gov (United States)

    Villagran-Vargas, Edgar; Rodríguez-Sosa, Leonardo; Hustert, Reinhold; Blicher, Andreas; Laub, Katrine; Heimburg, Thomas

    2013-02-01

    In this work, we analyzed the interpulse interval (IPI) of doublets and triplets in single neurons of three biological models. Pulse trains with two or three spikes originate from the process of sensory mechanotransduction in neurons of the locust femoral nerve, as well as through spontaneous activity both in the abdominal motor neurons and the caudal photoreceptor of the crayfish. We show that the IPI for successive low-frequency single action potentials, as recorded with two electrodes at two different points along a nerve axon, remains constant. On the other hand, IPI in doublets either remains constant, increases or decreases by up to about 3 ms as the pair propagates. When IPI increases, the succeeding pulse travels at a slower speed than the preceding one. When IPI is reduced, the succeeding pulse travels faster than the preceding one and may exceed the normal value for the specific neuron. In both cases, IPI increase and reduction, the speed of the preceding pulse differs slightly from the normal value, therefore the two pulses travel at different speeds in the same nerve axon. On the basis of our results, we may state that the effect of attraction or repulsion in doublets suggests a tendency of the spikes to reach a stable configuration. We strongly suggest that the change in IPI during spike propagation of doublets opens up a whole new realm of possibilities for neural coding and may have major implications for understanding information processing in nervous systems. Copyright © 2012 Wiley Periodicals, Inc.

  14. LA SITUATION DES ÉCREVISSES EN FRANCE RÉSULTATS DES ENQUÊTES NATIONALES RÉALISÉES ENTRE 1977 ET 2006 PAR LE CONSEIL SUPÉRIEUR DE LA PÊCHE

    Directory of Open Access Journals (Sweden)

    COLLAS M.

    2007-07-01

    Full Text Available Depuis la fin du XIX° siècle, la distribution des écrevisses en France a connu de profonds bouleversements, et l’introduction d’écrevisses allochtones en provenance essentiellement du continent nord-américain, a irrémédiablement modifié le paysage astacologique français et européen. Les quatre enquêtes réalisées en France par le Conseil Supérieur de la Pêche depuis 1977, ont permis de suivre l’évolution des différentes espèces d’écrevisses recensées sur le territoire national, mettant à chaque fois en évidence la forte expansion des espèces exotiques et le recul des espèces natives. L’enquête de 2006 n’échappe pas à cette tendance et la situation de nos trois espèces d’écrevisses doit désormais être considérée comme alarmante. Deux de ces espèces se caractérisent par un statut de conservation proche de l’extinction (Austropotamobius torrentium et Astacus astacus alors que la troisième, Austropotamobius pallipes est « réfugiée » sur les secteurs apicaux des bassins versants, confinée sur des zones soumises aux premières manifestations du changement climatique et isolées par les espèces exotiques qui progressent de plus en plus vers l’amont. En effet, l’écrevisse du Pacifique (Pacifastacus leniusculus, mais aussi l’écrevisse rouge de Louisiane (Procamabrus clarkii, sont les espèces qui montrent la plus forte expansion géographique durant la période 2001-2006. Partout elles apparaissent comme des concurrents redoutables, plus agressifs, résistants aux pathologies, capables de coloniser des habitats variés…. Ces deux espèces en particulier étendent leur aire de répartition et colonisent chaque année de nouveaux départements, de nouveaux cours d’eau, éliminant par là même, les espèces autochtones. L’expansion des écrevisses introduites, l’arrivée récente en France d’une nouvelle espèce (Orconectes juvenilis et les modifications de la Loi autorisant dor

  15. Web Access to Digitised Content of the Exhibition Novo Mesto 1848-1918 at the Dolenjska Museum, Novo Mesto

    Directory of Open Access Journals (Sweden)

    Majda Pungerčar

    2013-09-01

    individually or in a group of visitors as a quick test at the end of a visit to the exhibition. The computer game Cray Fish Hunting on the River of Krka was tailored to young visitors. It described the geographical position of Novo mesto on the Krka peninsula and some objects on the riverside (wooden baths, the old bridge, the dam and the mill. Hunting noble cray-fish was very extensive in the Novo mesto region until the outburst of the cray-fish plague. It is said that up to 100,000 cay fish were caught annually and transported to all major towns of the then Austrian Empire. The original museum collections were preserved by scanning precious items which were kept in depots. Digitised materials accessible on the museum website met the needs of the majority of users and provided expanded access to the museum collection through presentation of graphic materials in virtual exhibition on the web which was much more comprehensive than a printed catalogue. There was also the possibility of remote access to the museum website which was very important for tourists and museum visitors with special needs. It was possible to design customer tailored presentations on specific themes (postcards from the period of national awakening, local societies, middle class garments etc.. Digital content was also available to school teachers to discuss the themes of interest with their pupils or students either before or after visiting the exhibition. There are many pitfalls and limitations of digitisation, the biggest two being staff deficiency and shrinking budget. Furthermore, there are difficulties with the technical support, gathering information on the implementation process, seeking partners to digitise materials etc. Besides, the question of long term digital archiving is of vital importance.

  16. Beautiful, but also potentially invasive

    Directory of Open Access Journals (Sweden)

    Lipták Boris

    2015-03-01

    Full Text Available Introduction of non-indigenous exotic species to new areas, where they may establish viable populations and become invasive, is a considerable problem in the protection of nature worldwide, as these species may alter the indigenous species population structure and potentially even decrease the biodiversity. The European fauna underwent through major negative changes on the continent and nowadays, it experiences another new treat, represented by the expanding aquarium pet trade, and with it, associated species (and disease introductions. Exotic freshwater crustaceans are one of the taxa widely incorporated in the business, counting a remarkable number of species. Recent records of the exotic marbled crayfish or Marmorkrebs (Procambarus fallax f. virginalis in German in open ecosystems in Slovakia pointed to human-mediated introductions associated with aquarium pet trade in the country. In this regard, a study of the aquarium pet trade both in expositions and shops and online was assessed. Several crustacean taxa are available both in pet trade exhibitions and online through the Internet. Altogether 26 different species were identified in the aquarium trade in Slovakia. These are Procambarus fallax f. virginalis, P. clarkii, P. alleni, Cherax quadricarinatus, C. destructor, C. holthuisi, C. peknyi, Cambarellus patzcuarensis and C. diminutus occurring in the aquarium pet trade in Slovakia (n = 9. Procambarus fallax f. virginalis, P. clarkii and C. patzuarensis are the most common in this regard. There is also a quantity of other related taxa in the aquarium pet trade in Slovakia, mainly Caridina spp. (n = 5, Neocaridina spp. (n = 4, Atyopsis moluccensis, Atya gabonensis, Arachnochium kulsiense and several taxa of exotic crabs (n = 5 belonging to three different genera (Cardiosoma, Geosesarma and Gecarinus present. Neocaridina davidi is identified as the most frequent in this regard. As some of the species can become established and form viable

  17. Simultaneous Determination of Methoxylated Polybrominated Diphenyl Ethers and Polybrominated Diphenyl Ethers in Water, Soil and Sediment from China by GC-MS.

    Science.gov (United States)

    Hu, Xiaozhong; Hu, Decong; Chen, Wei; Wu, Bin; Lin, Changjun

    2015-09-01

    Polybrominated diphenyl ethers (PBDEs) are widely used brominated flame retardants, which are increasingly reported in the environment. Methoxylated polybrominated diphenyl ethers (MeO-PBDEs) are structural analogs to PBDEs and reported as natural products and novel pollutants present in the environment. First, a new isotopic dilution GC-MS method was developed in this study to simultaneously determine 13 PBDEs and 8 MeO-PBDEs in water, soil and sediment. Liquid/liquid extraction, pressurized liquid extraction and multi-layer silica gel column chromatography cleanup were used, and some important steps and crucial parameters were modified and intensified compared with the other literatures. Besides, the conditions of GC and MS were also optimized. The limits of quantitation values of 0.005-0.1 and 0.02-0.1 µg L(-1) in water were calculated for PBDEs and MeO-PBDEs, respectively; so did 0.25-5 and 1-5 µg kg(-1) dry weight in soil and sediment. In addition, good repeatability and accuracy of the whole method were achieved. Moreover, 60 water and 30 sediment samples for aquaculture crayfish and freshwater fish collected from aquatic products production base, 40 soil samples collected from agricultural products production base and also 20 Yangtze River water samples and 20 Hanjiang River water samples collected from different sampling situations near Wuhan, Hubei province along the Yangtze River and the Hanjiang River were analyzed to determine whether they are contaminated by PBDEs and MeO-PBDEs. Using the established methods, it was found that PBDEs or MeO-PBDEs emerged in 4 of 60 water samples for aquatic products, 3 of 40 soils, and 2 of 30 sediments and in low µg kg(-1) dry weight for soil and sediments and low µg L(-1) for water. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  18. Ecological and physiological parameters of mercury and cesium-137 accumulation in the raccoon

    International Nuclear Information System (INIS)

    Davis, A.H.

    1981-01-01

    Raccoons from 4 regions in the southeastern Coastal Plain were evaluated for mercury content. Mercury content of hair when used as an indicator of total body mercury content was significantly different among 3 of the 4 areas: Okefenokee Swamp, Eglin Air Force Base, and Sapelo Island on the Georgia Coast. Raccoons from Echols County Georgia were not significantly different from those of the Okefenokee. Mercury in the liver and kidney was significantly different between Okefenokee and Sapelo. There was a strong correlation between the age of the raccoon and the mercury in hair, with older animals having higher concentrations. This relationship was also valid for most other tissues. There was evidence that mercury content in some tissues was correlated with the season and the body condition of the raccoon. Mercury was not transferred through the placenta to the fetal raccoons. There was a strong relationship of mercury content to raccoon behavioral characteristics. Raccoon body weight was slightly different between the areas studied. Cesium-137 values in raccoons were significantly different between the Okefenokee and Sapelo Island. Cesium-137 content was correlated with raccoon age, body weight, and mercury content. Generally non-detectable levels of chlorinated hydrocarbons and PCB were found in Okefenokee raccoons. Mercury concentrations in crayfish were generally low but probably of importance in the raccoon food chain. The biological half life of mercury in brain, gonad, pancreas, spleen, heart, and lung was approximately 52 days. The half-life of mercury in muscle was 35 days. Mercury content of hair, liver, and kidney decreased at very slow rates, with biological half lives of 229, 108, and 138 days. This was probably due to the role of these tissues in clearance of mercury from the body, and to the molting pattern of raccoon hair

  19. Late Pleistocene fishes of the Tennessee River Basin: an analysis of a late Pleistocene freshwater fish fauna from Bell Cave (site ACb-2) in Colbert County, Alabama, USA.

    Science.gov (United States)

    Jacquemin, Stephen J; Ebersole, Jun A; Dickinson, William C; Ciampaglio, Charles N

    2016-01-01

    The Tennessee River Basin is considered one of the most important regions for freshwater biodiversity anywhere on the globe. The Tennessee River Basin currently includes populations of at least half of the described contemporary diversity of extant North American freshwater fishes, crayfish, mussel, and gastropod species. However, comparatively little is known about the biodiversity of this basin from the Pleistocene Epoch, particularly the late Pleistocene (∼10,000 to 30,000 years B.P.) leading to modern Holocene fish diversity patterns. The objective of this study was to describe the fish assemblages of the Tennessee River Basin from the late Pleistocene using a series of faunas from locales throughout the basin documented from published literature, unpublished reports, and an undocumented fauna from Bell Cave (site ACb-2, Colbert County, AL). Herein we discuss 41 unequivocal taxa from 10 late Pleistocene localities within the basin and include a systematic discussion of 11 families, 19 genera, and 24 identifiable species (28 unequivocal taxa) specific to the Bell Cave locality. Among the described fauna are several extirpated (e.g., Northern Pike Esox lucius, Northern Madtom Noturus stigmosus) and a single extinct (Harelip Sucker Moxostoma lacerum) taxa that suggest a combination of late Pleistocene displacement events coupled with more recent changes in habitat that have resulted in modern basin diversity patterns. The Bell Cave locality represents one of the most intact Pleistocene freshwater fish deposits anywhere in North America. Significant preservational, taphonomic, sampling, and identification biases preclude the identification of additional taxa. Overall, this study provides a detailed look into paleo-river ecology, as well as freshwater fish diversity and distribution leading up to the contemporary biodiversity patterns of the Tennessee River Basin and Mississippi River Basin as a whole.

  20. Late Pleistocene fishes of the Tennessee River Basin: an analysis of a late Pleistocene freshwater fish fauna from Bell Cave (site ACb-2 in Colbert County, Alabama, USA

    Directory of Open Access Journals (Sweden)

    Stephen J. Jacquemin

    2016-02-01

    Full Text Available The Tennessee River Basin is considered one of the most important regions for freshwater biodiversity anywhere on the globe. The Tennessee River Basin currently includes populations of at least half of the described contemporary diversity of extant North American freshwater fishes, crayfish, mussel, and gastropod species. However, comparatively little is known about the biodiversity of this basin from the Pleistocene Epoch, particularly the late Pleistocene (∼10,000 to 30,000 years B.P. leading to modern Holocene fish diversity patterns. The objective of this study was to describe the fish assemblages of the Tennessee River Basin from the late Pleistocene using a series of faunas from locales throughout the basin documented from published literature, unpublished reports, and an undocumented fauna from Bell Cave (site ACb-2, Colbert County, AL. Herein we discuss 41 unequivocal taxa from 10 late Pleistocene localities within the basin and include a systematic discussion of 11 families, 19 genera, and 24 identifiable species (28 unequivocal taxa specific to the Bell Cave locality. Among the described fauna are several extirpated (e.g., Northern Pike Esox lucius, Northern Madtom Noturus stigmosus and a single extinct (Harelip Sucker Moxostoma lacerum taxa that suggest a combination of late Pleistocene displacement events coupled with more recent changes in habitat that have resulted in modern basin diversity patterns. The Bell Cave locality represents one of the most intact Pleistocene freshwater fish deposits anywhere in North America. Significant preservational, taphonomic, sampling, and identification biases preclude the identification of additional taxa. Overall, this study provides a detailed look into paleo-river ecology, as well as freshwater fish diversity and distribution leading up to the contemporary biodiversity patterns of the Tennessee River Basin and Mississippi River Basin as a whole.

  1. Studies of axon-glial cell interactions and periaxonal K+ homeostasis--II. The effect of axonal stimulation, cholinergic agents and transport inhibitors on the resistance in series with the axon membrane.

    Science.gov (United States)

    Hassan, S; Lieberman, E M

    1988-06-01

    The small electrical resistance in series with the axon membrane is generally modeled as the intercellular pathway for current flow through the periaxonal glial (Schwann cell) sheath. The series resistance of the medial giant axon of the crayfish, Procambarus clarkii, was found to vary with conditions known to affect the electrical properties of the periaxonal glia. Series resistance was estimated from computer analysed voltage waveforms generated by axial wire-constant current and space clamp techniques. The average series resistance for all axons was 6.2 +/- 0.5 omega cm2 (n = 128). Values ranged between 1 and 30 omega cm2. The series resistance of axons with low resting membrane resistance (less than 1500 omega cm2) increased an average of 30% when stimulated for 45 s to 7 min (50 Hz) whereas the series resistance of high membrane resistance (greater than 1500 omega cm2) axons decreased an average of 10%. Carbachol (10(-7) M) caused the series resistance of low membrane resistance axons to decrease during stimulation but had no effect on high membrane resistance axons. d-Tubocurare (10(-8) M) caused the series resistance of high membrane resistance axons to increase during stimulation but had no effect on low membrane resistance axons. Bumetanide, a Na-K-Cl cotransport inhibitor and low [K+]o, prevented the stimulation-induced increase in series resistance of low membrane resistance axons but had no effect on the high membrane resistance axons. The results suggest that the series resistance of axons varies in response to the activity of the glial K+ uptake mechanisms stimulated by the appearance of K+ in the periaxonal space during action potential generation.(ABSTRACT TRUNCATED AT 250 WORDS)

  2. Trophic interactions of the endangered Southern river otter ( Lontra provocax) in a Chilean Ramsar wetland inferred from prey sampling, fecal analysis, and stable isotopes

    Science.gov (United States)

    Franco, Marcela; Guevara, Giovany; Correa, Loreto; Soto-Gamboa, Mauricio

    2013-04-01

    Non-invasive methodological approaches are highly recommended and commonly used to study the feeding ecology of elusive and threatened mammals. In this study, we use multiple lines of evidence to assess the feeding strategies of the endangered Southern river otter, by determining seasonal prey availability (electrofishing), analysis of undigested prey remains (spraints), and the use of stable isotopes (δ15N and δ13C) in otter spraints ( n = 262) and prey in a wetland ecosystem of southern Chile (39°49'S, 73°15'W). Fecal and isotopic analyses suggest that the otter diet is restricted to a few prey items, particularly the less-mobile, bottom-living, and larger prey such as crayfish ( Samastacus spinifrons, 86.11 %) and crabs ( Aegla spp., 32.45 %), supplemented opportunistically by cyprinids ( Cyprinus carpio, 9.55 %) and catfish ( Diplomystes camposensis, 5.66 %). The results suggest that the river otter is highly specialized in bottom foraging. Isotopic signatures of food sources and feces revealed a mid-upper trophic position for the Southern river otter, with either higher or lower δ15N values than their potential prey items. δ13C values for river otters were less enriched than their potential food resources. We suggest that due to their narrow trophic niche and possible dependence on only a few food items, this species may be highly vulnerable to the reduction in its prey populations. Finally, maintaining the ecological interactions between Southern river otters and their prey is considered a central priority for the survival of this endangered carnivore mammal.

  3. Endocrine effects of contaminated sediments on the freshwater snail Potamopyrgus antipodarum in vivo and in the cell bioassays in vitro.

    Science.gov (United States)

    Mazurová, E; Hilscherová, K; Jálová, V; Köhler, H-R; Triebskorn, R; Giesy, J P; Bláha, L

    2008-09-17

    Lake Pilnok located in the black coal-mining region Ostrava-Karvina, Czech Republic, contains sediments highly contaminated with powdered waste coal. Moreover, population of the endangered species of narrow-clawed crayfish Pontastacus leptodactylus with high proportion of intersex individuals (18%) was observed at this site. These findings motivated our work that aimed to evaluate contamination, endocrine disruptive potency using in vitro assays and in vivo effects of contaminated sediments on reproduction of sediment-dwelling invertebrates. Chemical analyses revealed low concentrations of persistent chlorinated compounds and heavy metals but concentrations of polycyclic aromatic hydrocarbons (PAH) were high (sum of 16 PAHs 10 microg/g dw). Organic extracts from sediments caused significant in vitro AhR-mediated activity in the bioassay with H4IIE-luc cells, estrogenicity in MVLN cells and anti-androgenicity in recombinant yeast assay, and these effects could be attributed to non-persistent compounds derived from the waste coal. We have also observed significant in vivo effects of the sediments in laboratory experiments with the Prosobranchian euryhaline mud snail Potamopyrgus antipodarum. Sediments from Lake Pilnok as well as organic extracts of the sediments (externally added to the control sediment) significantly affected fecundity during 8 weeks of exposure. The effects were stimulations of fecundity at lower concentrations at the beginning of the experiment followed by inhibitions of fecundity and general toxicity. Our study indicates presence of chemicals that affected endocrine balance in invertebrates, and emphasizes the need for integrated approaches combining in vitro and in vivo bioassays with identification of chemicals to elucidate ecotoxicogical impacts of contaminated sediment samples.

  4. Long-term fate and bioavailability of sediment associated 2,3,7,8-tetrachlorodibenzofuran in littoral enclosures

    Energy Technology Data Exchange (ETDEWEB)

    Currie, R.S.; Fairchild, W.L.; Holoka, M.H.; Muir, D.C.G.

    2000-06-01

    the fate and bioavailability of 2,3,7,8-tetrachlorodibenzofuran (TCDF; 4,6-tritium labeled) was examined over a 3-year period in littoral enclosures in a small oligotrophic lake in the Experimental Lakes Area. Tetrachlorodibenzofuran was added as a single dose or as five small multiple additions over a 5-d period in a sediment slurry. Tetrachlorodibenzofuran was rapidly redistributed, mainly to bottom sediments reflecting removal on settling particles. Between 0 and 120 d. 80 to 90% of TCDF in the water column was associated with particles (>1 {micro}m). The highest concentration of TCDF in suspended particles was consistently observed in the smallest size fraction (0.22--1 {micro}m) at 326 to 464 d post treatment. Mode of addition had no effect on TCDF concentrations in water or surficial sediments or pore waters throughout the experiment. Mean TCDF concentrations in surficial sediment were 1.830 {+-} 1.180 pg/g whereas they averaged 1.260 {+-} 596 pg/g OC from 318 to 851 d post treatment. Increasing concentrations of TCDE in lower sediment layers at 952 d suggests that TCDF was either diffusing into the sediment or undergoing burial. Fugacity (f) calculations indicated that the TCDF in enclosures shifted from disequilibrium favoring the water column to a disequilibrium with respect to bottom sediments from day 21 onward. Initially, TCDF was more bioavailable to filtering and deposit feeders (mussels, Chironomidae, Hexagenia sp., and zooplankton) in enclosures receiving multiple additions; however, differences were rarely statistically significant. Concentrations of TCDF in all organisms were initially high, and they decreased in later sampling periods. Biota--sediment-accumulation factors (BSAFs) in mussels and crayfish were >1 in the early sampling periods, which reflected greater bioavailability of the added particle-borne TCDF. By 851 d, BSAFs had declined to 0.02 to 0.04, reflecting removal of TCDF from the water column and from surficial sediments.

  5. The emergence of lobsters: phylogenetic relationships, morphological evolution and divergence time comparisons of an ancient group (decapoda: achelata, astacidea, glypheidea, polychelida).

    Science.gov (United States)

    Bracken-Grissom, Heather D; Ahyong, Shane T; Wilkinson, Richard D; Feldmann, Rodney M; Schweitzer, Carrie E; Breinholt, Jesse W; Bendall, Matthew; Palero, Ferran; Chan, Tin-Yam; Felder, Darryl L; Robles, Rafael; Chu, Ka-Hou; Tsang, Ling-Ming; Kim, Dohyup; Martin, Joel W; Crandall, Keith A

    2014-07-01

    Lobsters are a ubiquitous and economically important group of decapod crustaceans that include the infraorders Polychelida, Glypheidea, Astacidea and Achelata. They include familiar forms such as the spiny, slipper, clawed lobsters and crayfish and unfamiliar forms such as the deep-sea and "living fossil" species. The high degree of morphological diversity among these infraorders has led to a dynamic classification and conflicting hypotheses of evolutionary relationships. In this study, we estimated phylogenetic relationships among the major groups of all lobster families and 94% of the genera using six genes (mitochondrial and nuclear) and 195 morphological characters across 173 species of lobsters for the most comprehensive sampling to date. Lobsters were recovered as a non-monophyletic assemblage in the combined (molecular + morphology) analysis. All families were monophyletic, with the exception of Cambaridae, and 7 of 79 genera were recovered as poly- or paraphyletic. A rich fossil history coupled with dense taxon coverage allowed us to estimate and compare divergence times and origins of major lineages using two drastically different approaches. Age priors were constructed and/or included based on fossil age information or fossil discovery, age, and extant species count data. Results from the two approaches were largely congruent across deep to shallow taxonomic divergences across major lineages. The origin of the first lobster-like decapod (Polychelida) was estimated in the Devonian (∼409-372 Ma) with all infraorders present in the Carboniferous (∼353-318 Ma). Fossil calibration subsampling studies examined the influence of sampling density (number of fossils) and placement (deep, middle, and shallow) on divergence time estimates. Results from our study suggest including at least 1 fossil per 10 operational taxonomic units (OTUs) in divergence dating analyses. [Dating; decapods; divergence; lobsters; molecular; morphology; phylogenetics.]. © The

  6. Simultaneous Sampling of Flow and Odorants by Crustaceans can Aid Searches within a Turbulent Plume

    Directory of Open Access Journals (Sweden)

    Swapnil Pravin

    2013-12-01

    Full Text Available Crustaceans such as crabs, lobsters and crayfish use dispersing odorant molecules to determine the location of predators, prey, potential mates and habitat. Odorant molecules diffuse in turbulent flows and are sensed by the olfactory organs of these animals, often using a flicking motion of their antennules. These antennules contain both chemosensory and mechanosensory sensilla, which enable them to detect both flow and odorants during a flick. To determine how simultaneous flow and odorant sampling can aid in search behavior, a 3-dimensional numerical model for the near-bed flow environment was created. A stream of odorant concentration was released into the flow creating a turbulent plume, and both temporally and spatially fluctuating velocity and odorant concentration were quantified. The plume characteristics show close resemblance to experimental measurements within a large laboratory flume. Results show that mean odorant concentration and it’s intermittency, computed as dc/dt, increase towards the plume source, but the temporal and spatial rate of this increase is slow and suggests that long measurement times would be necessary to be useful for chemosensory guidance. Odorant fluxes measured transverse to the mean flow direction, quantified as the product of the instantaneous fluctuation in concentration and velocity, v’c’, do show statistically distinct magnitude and directional information on either side of a plume centerline over integration times of <0.5 s. Aquatic animals typically have neural responses to odorant and velocity fields at rates between 50 and 500 ms, suggesting this simultaneous sampling of both flow and concentration in a turbulent plume can aid in source tracking on timescales relevant to aquatic animals.

  7. Impact of effluents from Tihange nuclear plant on the Meuse ecosystem: a five year in situ study and experimental approach 1976 -1980

    International Nuclear Information System (INIS)

    Clercq-Versele, H. de; Kirchmann, R.

    1982-07-01

    The aim of present multidisciplinary study, started in 1975, was to evaluate the influence of liquid effluent releases from a PWR-type nuclear reactor on the ecosystem of running water. The Tihange-1 nuclear power plant, along the Meuse river near Liege, has been selected as site for this study, which situates in the general context of the industrial and urban pollution of this region. The in situ biological research dealt with phytoplankton, microphytobenthos and bryophytic populations on the one hand, and with zooplankton, macroinvertebrates and fish on the other hand. The impact of the releases on certain aquatic organisms has been studied with the help of experimental devices (pools and rafts). Laboratory research has been carried out on an alga type representative of Meuse phytoplankton. It could be concluded that a temperature increase of the Meuse water (generally 2 to 3 0 C), although it has no detectable qualitative influence on the various links of the Meuse ecosystem, seems to promote the development of more temperature-tolerant species and to influence biological parameters such as growth and reproduction of aquatic animals. Although the legal limit (namely 0.3 mg/l in the water downstream the releases) is always respected, chlorination of the Meuse water gives rise to a decrease of the photosynthetic activity in aquatic mosses and creates asphyxiation phenomena in fish and crayfish. The utility of certain animal organisms of the Meuse biocenose as bio-indicators of the radionuclides present in the releases, has been confirmed. The alga cultures are also very adequate for the evaluation of the biological availability of some radioisotopes such as tritium. (author)

  8. Transient dwarfism of soil fauna during the Paleocene-Eocene Thermal Maximum.

    Science.gov (United States)

    Smith, Jon J; Hasiotis, Stephen T; Kraus, Mary J; Woody, Daniel T

    2009-10-20

    Soil organisms, as recorded by trace fossils in paleosols of the Willwood Formation, Wyoming, show significant body-size reductions and increased abundances during the Paleocene-Eocene Thermal Maximum (PETM). Paleobotanical, paleopedologic, and oxygen isotope studies indicate high temperatures during the PETM and sharp declines in precipitation compared with late Paleocene estimates. Insect and oligochaete burrows increase in abundance during the PETM, suggesting longer periods of soil development and improved drainage conditions. Crayfish burrows and molluscan body fossils, abundant below and above the PETM interval, are significantly less abundant during the PETM, likely because of drier floodplain conditions and lower water tables. Burrow diameters of the most abundant ichnofossils are 30-46% smaller within the PETM interval. As burrow size is a proxy for body size, significant reductions in burrow diameter suggest that their tracemakers were smaller bodied. Smaller body sizes may have resulted from higher subsurface temperatures, lower soil moisture conditions, or nutritionally deficient vegetation in the high-CO(2) atmosphere inferred for the PETM. Smaller soil fauna co-occur with dwarf mammal taxa during the PETM; thus, a common forcing mechanism may have selected for small size in both above- and below-ground terrestrial communities. We predict that soil fauna have already shown reductions in size over the last 150 years of increased atmospheric CO(2) and surface temperatures or that they will exhibit this pattern over the next century. We retrodict also that soil fauna across the Permian-Triassic and Triassic-Jurassic boundary events show significant size decreases because of similar forcing mechanisms driven by rapid global warming.

  9. Feeding habits of the genet Genetta genetta in an Iberian continental wetland

    Directory of Open Access Journals (Sweden)

    Maite Sánchez

    2009-02-01

    Full Text Available Abstract This study quantified the diet of the genet Genetta genetta in an Iberian continental wetland, the Galachos Nature Reserve, northern Spain, based on the frequency with which items appeared in five monthly-surveyed latrines during 2004-2005. Prey types were identified de visu using identification keys and expert advice. the genet was confirmed as an opportunistic and generalist predator, its diet including mammals (95.0%, plants (68.3% and arthropods (60.0% as main prey. With the exception of a newly available prey species, the alien crayfish Procambarus clarkii, the genet probably consumed arthropods because of chance encounters rather than active search. The consumption of fruits and small mammals varied seasonally. Riassunto Alimentazione della genetta Genetta genetta in un'area umida continentale della penisola iberica La dieta della genetta è stata investigata in un'area umida interna della Spagna settentrionale, la riserva Naturale dei Galachos. La frequenza di ciascuna categoria alimentare è stata espressa come numero di occorrenze mansili in cinque latrine monitorate per il periodo 2004-2005. Le categorie sono state identificate de visu tramite chiavi per il riconoscimento o l'intervento di singoli esperti. I risultati confermano il comportamento alimentare generalista e opportunista della genetta. La dieta ha incluso principalmente mammiferi (95%, vegetali (68.3% e artropodi (60%. Questi ultimi, con l'eccezione del gambero Procambarus clarkii, introdotto e di recente presenza, sono probabilmente utilizzati in modo opportunistico, piuttosto che in seguito a ricerca attiva. L'uso dei frutti e dei micromammiferi varia stagionalmente.

  10. Variations in anthropogenic silver in a large Patagonian lake correlate with global shifts in photographic processing technology.

    Science.gov (United States)

    Juncos, Romina; Campbell, Linda; Arcagni, Marina; Daga, Romina; Rizzo, Andrea; Arribére, María; Ribeiro Guevara, Sergio

    2017-04-01

    At the beginning of the 21st century, digital imaging technology replaced the traditional silver-halide film photography which had implications in Ag contamination. Lake Nahuel Huapi is a popular Patagonia tourist destination impacted by municipal silver (Ag) contamination from photographic processing facilities since 1990's. Silver concentrations in a dated sediment core from the lake bottom showed a 10-fold increase above background levels in the second half of the 20th century, then a decrease. This trend corresponds well with published annual global photography industry demand for Ag, which clearly shows the evolution and replacement of the traditional silver-halide film photography by digital imaging technology. There were significant decreases in Ag concentrations in sediments, mussels and fish across the lake between 1998 and 2011. Lower trophic organisms had variable whole-body Ag concentrations, from 0.2-2.6 μg g -1 dry weight (DW) in plankton to 0.02-3.1 μg g -1 DW in benthic macroinvertebrates. Hepatic Ag concentrations in crayfish, mussels and predatory fish were significantly elevated relative to muscle which often have Ag concentrations below the detection limit (0.01-0.05 μg g -1 DW). Trophodynamic analyses using δ 15 N and whole-body invertebrate and muscle Ag concentrations indicated food web biodilution trends. High sedimentation rates in conjunction with the reduction of silver waste products discharged to the lake, as a result of the change to digital image processing technologies, are resulting in unplanned but welcome remediation of the Ag contamination in Lake Nahuel Huapi. Copyright © 2017 Elsevier Ltd. All rights reserved.

  11. E.N.V.I.R.H.O.M.. Bioaccumulation of radionuclides in situations of chronic exposure of ecosystems and members of the public; Progress Report 2 covering the period June 2003 - September 2005

    International Nuclear Information System (INIS)

    2005-01-01

    The main objective of E.N.V.I.R.H.O.M. is to better assess real effects caused by chronic exposure to low levels of radioactive contaminants. This includes for example consequences on nervous system, immunity or metabolisms, consequences on reproduction, consequences on feeding processes and consequences on ecosystem productivity. E.N.V.I.R.O.M. has set a priority on radionuclides that are suspected of accumulation in organisms., it has also a priority on radionuclides that act not only with gamma rays. The program was started in 2001 and uranium was chosen to test the methodology. The two first years of E.N.V.I.R.H.O.M. demonstrated clearly that a signal can be seen even as a consequence of moderate exposure. It was also found that some simplifying hypothesis may be false. For example the simple biokinetic model assuming that the result of a continuous feeding is equivalent to the convolution of successive punctual inputs is not always true. When the input is constant, it should involve a steady state following an increase. Instead of that, a decrease has been observed in some cases (rats, crayfish). The second two years period ( 2004-2005) used the same strategy in a larger scale. As regard biota, the list of test organisms was extended (daphnia, insects)and also the tested radionuclides (Se, Tc, Am). The list of studied functions was extended (behavior and sleep, neurotransmission, genomic effects, intestinal immune capacity, drug metabolism, vitamin D metabolism). The E.N.V.I.R.H.O.M. program is the main experimental part of a container program devoted to chronic risks. (N.C.)

  12. Some effects of aldrin-treated rice on Gulf Coast wildlife

    Science.gov (United States)

    Flickinger, Edward L.; King, K.A.

    1972-01-01

    Wildlife casualties from aldrin-dieldrin poisoning are associated with the planting of aldrin-treated rice seed along the Texas Gulf Coast. The fulvous tree duck (Dendrocygna bicolor), which depends on the rice field habitats and is highly susceptible to aldrin-dieldrin poisoning, is suffering a serious population decline in that area. Dead waterfowl, shorebirds, and passerines were collected on study areas in Wharton, Brazoria, and Chambers counties, Texas, from 1967 through 1971. Residues of aldrin or dieldrin were found in all samples of bird casualties and in all eggs, scavengers, predators, fish, frogs, invertebrates, and soils. Fulvous tree ducks appeared to be less resistant to aldrin than other ducks. Dieldrin residues in brains of dead fulvous tree ducks were low, but whole-body residues were as high as 16 ppm. Brains of other dead ducks and geese averaged 10 ppm dieldrin. Some dead birds were exposed by eating treated rice seed, but many dead birds with high dieldrin residues were species that feed largely on invertebrates. Although soil residues were low, snails and crayfish contained enough aldrin and dieldrin (average 9.5 ppm) to account for deaths in birds that fed heavily on these invertebrates over a period of time. When fulvous tree ducks were penned for 3 days in fields aerially planted with treated seed, 3 of 10 birds died with brain residues of 2.5, 2.9, and 6.8 ppm dieldrin, and others were intoxicated. None of eight died, and some gained weight, when penned in fields planted with untreated seed. This study adds further evidence for the suspected lethal effects of aldrin-treated rice seed on wild birds and other wildlife in rice field habitats.

  13. Measuring maximum and standard metabolic rates using intermittent-flow respirometry: a student laboratory investigation of aerobic metabolic scope and environmental hypoxia in aquatic breathers.

    Science.gov (United States)

    Rosewarne, P J; Wilson, J M; Svendsen, J C

    2016-01-01

    Metabolic rate is one of the most widely measured physiological traits in animals and may be influenced by both endogenous (e.g. body mass) and exogenous factors (e.g. oxygen availability and temperature). Standard metabolic rate (SMR) and maximum metabolic rate (MMR) are two fundamental physiological variables providing the floor and ceiling in aerobic energy metabolism. The total amount of energy available between these two variables constitutes the aerobic metabolic scope (AMS). A laboratory exercise aimed at an undergraduate level physiology class, which details the appropriate data acquisition methods and calculations to measure oxygen consumption rates in rainbow trout Oncorhynchus mykiss, is presented here. Specifically, the teaching exercise employs intermittent flow respirometry to measure SMR and MMR, derives AMS from the measurements and demonstrates how AMS is affected by environmental oxygen. Students' results typically reveal a decline in AMS in response to environmental hypoxia. The same techniques can be applied to investigate the influence of other key factors on metabolic rate (e.g. temperature and body mass). Discussion of the results develops students' understanding of the mechanisms underlying these fundamental physiological traits and the influence of exogenous factors. More generally, the teaching exercise outlines essential laboratory concepts in addition to metabolic rate calculations, data acquisition and unit conversions that enhance competency in quantitative analysis and reasoning. Finally, the described procedures are generally applicable to other fish species or aquatic breathers such as crustaceans (e.g. crayfish) and provide an alternative to using higher (or more derived) animals to investigate questions related to metabolic physiology. © 2016 The Fisheries Society of the British Isles.

  14. Estudio reológico y microestructural de emulsiones concentradas de aceite de girasol en agua estabilizadas con proteínas agroalimentarias

    Directory of Open Access Journals (Sweden)

    Guerrero, A.

    2008-03-01

    Full Text Available Droplet Size Distribution (DSD and linear viscoelastic properties of concentrated o/w emulsions stabilized by different proteins (crayfish, gluten and soybean have been studied. A typical behaviour of highly concentrated emulsions with a high degree of flocculation has been found. An increase in energy input for the emulsification process or in emulsifier concentration leads to an increase in both viscoelastic moduli (G’, G’’ as well as to a decrease in droplet size. Thus, an enhancement of the entanglement network produced by association of protein molecules that are surrounding oil droplets or are present in the continuous phase takes place, leading to a significant improvement of emulsion stability.Se ha realizado un estudio de la distribución del tamaño de gotas y de las propiedades viscoelásticas lineales de emulsiones concentradas de aceite en agua, estabilizadas con diferentes proteínas (cangrejo, gluten y soja. Los sistemas estudiados siempre presentan un comportamiento típico de emulsiones altamente concentradas con un alto grado de floculación. Se ha observado que un incremento de la velocidad de agitación empleada durante la preparación o de la concentración de emulsionante dan lugar a un aumento de los módulos viscoelásticos (G’ y G’’ y a una disminución del tamaño de gotas. Por tanto se produce un reforzamiento del entramado formado por asociación de las gotas de fase dispersa y como consecuencia, un aumento en la estabilidad de las emulsiones.

  15. Astakine 2--the dark knight linking melatonin to circadian regulation in crustaceans.

    Directory of Open Access Journals (Sweden)

    Apiruck Watthanasurorot

    2013-03-01

    Full Text Available Daily, circadian rhythms influence essentially all living organisms and affect many physiological processes from sleep and nutrition to immunity. This ability to respond to environmental daily rhythms has been conserved along evolution, and it is found among species from bacteria to mammals. The hematopoietic process of the crayfish Pacifastacus leniusculus is under circadian control and is tightly regulated by astakines, a new family of cytokines sharing a prokineticin (PROK domain. The expression of AST1 and AST2 are light-dependent, and this suggests an evolutionarily conserved function for PROK domain proteins in mediating circadian rhythms. Vertebrate PROKs are transmitters of circadian rhythms of the suprachiasmatic nucleus (SCN in the brain of mammals, but the mechanism by which they function is unknown. Here we demonstrate that high AST2 expression is induced by melatonin in the brain. We identify RACK1 as a binding protein of AST2 and further provide evidence that a complex between AST2 and RACK1 functions as a negative-feedback regulator of the circadian clock. By DNA mobility shift assay, we showed that the AST2-RACK1 complex will interfere with the binding between BMAL1 and CLK and inhibit the E-box binding activity of the complex BMAL1-CLK. Finally, we demonstrate by gene knockdown that AST2 is necessary for melatonin-induced inhibition of the complex formation between BMAL1 and CLK during the dark period. In summary, we provide evidence that melatonin regulates AST2 expression and thereby affects the core clock of the crustacean brain. This process may be very important in all animals that have AST2 molecules, i.e. spiders, ticks, crustaceans, scorpions, several insect groups such as Hymenoptera, Hemiptera, and Blattodea, but not Diptera and Coleoptera. Our findings further reveal an ancient evolutionary role for the prokineticin superfamily protein that links melatonin to direct regulation of the core clock gene feedback loops.

  16. Mercury bioaccumulation along food webs in temperate aquatic ecosystems colonized by aquatic macrophytes in south western France.

    Science.gov (United States)

    Gentès, Sophie; Maury-Brachet, Régine; Guyoneaud, Rémy; Monperrus, Mathilde; André, Jean-Marc; Davail, Stéphane; Legeay, Alexia

    2013-05-01

    Mercury (Hg) is considered as an important pollutant for aquatic systems as its organic form, methylmercury (MeHg), is easily bioaccumulated and bioamplified along food webs. In various ecosystems, aquatic periphyton associated with macrophyte was identified as an important place for Hg storage and methylation by microorganisms. Our study concerns temperate aquatic ecosystems (South Western France) colonized by invasive macrophytes and characterized by high mercury methylation potentials. This work establishes original data concerning Hg bioaccumulation in organisms (plants, crustaceans, molluscs and fish) from five contrasting ecosystems. For low trophic level species, total Hg (THg) concentrations were low (from 27±2ngTHgg(-1)dw in asiatic clam Corbicula fluminea to 418±114ngTHgg(-1)dw in crayfish Procambarus clarkii). THg concentrations in some carnivorous fish (high trophic level) were close to or exceeded the International Marketing Level (IML) with values ranging from 1049±220ngTHgg(-1)dw in pike perch muscle (Sander lucioperca) to 3910±1307ngTHgg(-1)dw in eel muscle (Anguilla Anguilla). Trophic levels for the individuals were also evaluated through stable isotope analysis, and linked to Hg concentrations of organisms. A significant Hg biomagnification (r(2)= 0.9) was observed in the Aureilhan lake, despite the absence of top predator fish. For this site, Ludwigia sp. periphyton, as an entry point of Hg into food webs, is a serious hypothesis which remains to be confirmed. This study provides a first investigation of Hg transfer in the ecosystems of south western France and allows the assessment of the risk associated with the presence of Hg in aquatic food webs. Copyright © 2013 Elsevier Inc. All rights reserved.

  17. An evaluation of liquid ammonia (ammonium hydroxide) as a candidate piscicide

    Science.gov (United States)

    Ward, David L.; Morton-Starner, R.; Hedwall, Shaula J.

    2013-01-01

    Eradication of populations of nonnative aquatic species for the purpose of reintroducing native fish is often difficult because very few effective tools are available for removing aquatic organisms. This creates the need to evaluate new chemicals that could be used as management tools for native fish conservation. Ammonia is a natural product of fish metabolism and is naturally present in the environment at low levels, yet is known to be toxic to most aquatic species. Our objective was to determine the feasibility of using liquid ammonia as a fisheries management tool by evaluating its effectiveness at killing undesirable aquatic species and its persistence in a pond environment. A suite of invasive aquatic species commonly found in the southwestern USA were introduced into two experimental outdoor ponds located at the Rocky Mountain Research Station in Flagstaff, Arizona. Each pond was treated with ammonium hydroxide (29%) at 38 ppm. This target concentration was chosen because previous studies using anhydrous ammonia reported incomplete fish kills in ponds at concentrations less than 30 ppm. Water quality was monitored for 49 d to determine how quickly the natural bacteria in the environment converted the ammonia to nitrate. Ammonia levels remained above 8 ppm for 24 and 18 d, respectively, in ponds 1 and 2. Nitrite levels in each pond began to rise approximately 14 d after dosing with ammonia and stayed above 5 ppm for an additional 21 d in pond 1 and 18 d in pond 2. After 49 d all water in both ponds was drained and no fish, crayfish, or tadpoles were found to have survived the treatment, but aquatic turtles remained alive and appeared unaffected. Liquid ammonia appears to be an effective tool for removing many problematic invasive aquatic species and may warrant further investigation as a piscicide.

  18. Transient dwarfism of soil fauna during the Paleocene-Eocene Thermal Maximum

    Science.gov (United States)

    Smith, J.J.; Hasiotis, S.T.; Kraus, M.J.; Woody, D.T.

    2009-01-01

    Soil organisms, as recorded by trace fossils in paleosols of the Willwood Formation, Wyoming, show significant body-size reductions and increased abundances during the Paleocene-Eocene Thermal Maximum (PETM). Paleobotanical, paleopedologic, and oxygen isotope studies indicate high temperatures during the PETM and sharp declines in precipitation compared with late Paleocene estimates. Insect and oligochaete burrows increase in abundance during the PETM, suggesting longer periods of soil development and improved drainage conditions. Crayfish burrows and molluscan body fossils, abundant below and above the PETM interval, are significantly less abundant during the PETM, likely because of drier floodplain conditions and lower water tables. Burrow diameters of the most abundant ichnofossils are 30-46% smaller within the PETM interval. As burrow size is a proxy for body size, significant reductions in burrow diameter suggest that their tracemakers were smaller bodied. Smaller body sizes may have resulted from higher subsurface temperatures, lower soil moisture conditions, or nutritionally deficient vegetation in the high-CO2 atmosphere inferred for the PETM. Smaller soil fauna co-occur with dwarf mammal taxa during the PETM; thus, a common forcing mechanism may have selected for small size in both above- and below-ground terrestrial communities. We predict that soil fauna have already shown reductions in size over the last 150 years of increased atmospheric CO2 and surface temperatures or that they will exhibit this pattern over the next century. We retrodict also that soil fauna across the Permian-Triassic and Triassic-Jurassic boundary events show significant size decreases because of similar forcing mechanisms driven by rapid global warming.

  19. Prediction of the neuropeptidomes of members of the Astacidea (Crustacea, Decapoda) using publicly accessible transcriptome shotgun assembly (TSA) sequence data.

    Science.gov (United States)

    Christie, Andrew E; Chi, Megan

    2015-12-01

    The decapod infraorder Astacidea is comprised of clawed lobsters and freshwater crayfish. Due to their economic importance and their use as models for investigating neurochemical signaling, much work has focused on elucidating their neurochemistry, particularly their peptidergic systems. Interestingly, no astacidean has been the subject of large-scale peptidomic analysis via in silico transcriptome mining, this despite growing transcriptomic resources for members of this taxon. Here, the publicly accessible astacidean transcriptome shotgun assembly data were mined for putative peptide-encoding transcripts; these sequences were used to predict the structures of mature neuropeptides. One hundred seventy-six distinct peptides were predicted for Procambarus clarkii, including isoforms of adipokinetic hormone-corazonin-like peptide (ACP), allatostatin A (AST-A), allatostatin B, allatostatin C (AST-C) bursicon α, bursicon β, CCHamide, crustacean hyperglycemic hormone (CHH)/ion transport peptide (ITP), diuretic hormone 31 (DH31), eclosion hormone (EH), FMRFamide-like peptide, GSEFLamide, intocin, leucokinin, neuroparsin, neuropeptide F, pigment dispersing hormone, pyrokinin, RYamide, short neuropeptide F (sNPF), SIFamide, sulfakinin and tachykinin-related peptide (TRP). Forty-six distinct peptides, including isoforms of AST-A, AST-C, bursicon α, CCHamide, CHH/ITP, DH31, EH, intocin, myosuppressin, neuroparsin, red pigment concentrating hormone, sNPF and TRP, were predicted for Pontastacus leptodactylus, with a bursicon β and a neuroparsin predicted for Cherax quadricarinatus. The identification of ACP is the first from a decapod, while the predictions of CCHamide, EH, GSEFLamide, intocin, neuroparsin and RYamide are firsts for the Astacidea. Collectively, these data greatly expand the catalog of known astacidean neuropeptides and provide a foundation for functional studies of peptidergic signaling in members of this decapod infraorder. Copyright © 2015 Elsevier Inc

  20. Antimicrobial activity of a novel hypervariable immunoglobulin domain-containing receptor Dscam in Cherax quadricarinatus.

    Science.gov (United States)

    Li, Dan; Yu, Ai-Qing; Li, Xue-Jie; Zhu, You-Ting; Jin, Xing-Kun; Li, Wei-Wei; Wang, Qun

    2015-12-01

    Down syndrome cell adhesion molecule (Dscam) mediates innate immunity against pathogens in arthropods. Here, a novel Dscam from red claw crayfish Cherax quadricarinatus (CqDscam) was isolated. The CqDscam protein contains one signal peptide, ten immunoglobulin domains, six fibronectin type III domains, one transmembrane domain and cytoplasmic tail. CqDscam phylogenetically clustered with other invertebrate Dscams. Variable regions of CqDscam in N-terminal halves of Ig2 and Ig3 domains, complete Ig7 domain and TM domain can be reshuffled after transcription to produce a deluge of >37,620 potential alternative splice forms. CqDscam was detected in all tissues tested and abundantly expressed in immune system and nerve system. Upon lipopolysaccharides (LPS) and b-1, 3-glucans (Glu) challenged, the expression of CqDscam was up-regulated, while no response in expression occurred after injection with peptidoglycans (PG). Membrane-bound and secreted types of CqDscam were separated on the protein level, and were both extensively induced post LPS challenge. Membrane-bound CqDscam protein was not detected in the serum, but localized to the hemocyte surface by immuno-localization assay. In the antimicrobial assays, the recombinant LPS-induced isoform of CqDscam protein displayed bacterial binding and growth inhibitory activities, especially with Escherichia coli. These results suggested that CqDscam, as one of pattern-recognition receptors (PRRs), involved in innate immune recognition and defense mechanisms in C. quadricarinatus, possibly through alternative splicing. Copyright © 2015 Elsevier Ltd. All rights reserved.

  1. Comparative study of the fatty acid binding process of a new FABP from Cherax quadricarinatus by fluorescence intensity, lifetime and anisotropy.

    Directory of Open Access Journals (Sweden)

    Jiayao Li

    Full Text Available Fatty acid-binding proteins (FABPs are small cytosolic proteins, largely distributed in invertebrates and vertebrates, which accomplish uptake and intracellular transport of hydrophobic ligands such as fatty acids. Although long chain fatty acids play multiple crucial roles in cellular functions (structural, energy metabolism, regulation of gene expression, the precise functions of FABPs, especially those of invertebrate species, remain elusive. Here, we have identified and characterized a novel FABP family member, Cq-FABP, from the hepatopancreas of red claw crayfish Cherax quadricarinatus. We report the characterization of fatty acid-binding affinity of Cq-FABP by four different competitive fluorescence-based assays. In the two first approaches, the fluorescent probe 8-Anilino-1-naphthalenesulfonate (ANS, a binder of internal cavities of protein, was used either by directly monitoring its fluorescence emission or by monitoring the fluorescence resonance energy transfer occurring between the single tryptophan residue of Cq-FABP and ANS. The third and the fourth approaches were based on the measurement of the fluorescence emission intensity of the naturally fluorescent cis-parinaric acid probe or the steady-state fluorescence anisotropy measurements of a fluorescently labeled fatty acid (BODIPY-C16, respectively. The four methodologies displayed consistent equilibrium constants for a given fatty acid but were not equivalent in terms of analysis. Indeed, the two first methods were complicated by the existence of non specific binding modes of ANS while BODIPY-C16 and cis-parinaric acid specifically targeted the fatty acid binding site. We found a relationship between the affinity and the length of the carbon chain, with the highest affinity obtained for the shortest fatty acid, suggesting that steric effects primarily influence the interaction of fatty acids in the binding cavity of Cq-FABP. Moreover, our results show that the binding affinities

  2. Vulnerability of European freshwater catchments to climate change.

    Science.gov (United States)

    Markovic, Danijela; Carrizo, Savrina F; Kärcher, Oskar; Walz, Ariane; David, Jonathan N W

    2017-09-01

    Climate change is expected to exacerbate the current threats to freshwater ecosystems, yet multifaceted studies on the potential impacts of climate change on freshwater biodiversity at scales that inform management planning are lacking. The aim of this study was to fill this void through the development of a novel framework for assessing climate change vulnerability tailored to freshwater ecosystems. The three dimensions of climate change vulnerability are as follows: (i) exposure to climate change, (ii) sensitivity to altered environmental conditions and (iii) resilience potential. Our vulnerability framework includes 1685 freshwater species of plants, fishes, molluscs, odonates, amphibians, crayfish and turtles alongside key features within and between catchments, such as topography and connectivity. Several methodologies were used to combine these dimensions across a variety of future climate change models and scenarios. The resulting indices were overlaid to assess the vulnerability of European freshwater ecosystems at the catchment scale (18 783 catchments). The Balkan Lakes Ohrid and Prespa and Mediterranean islands emerge as most vulnerable to climate change. For the 2030s, we showed a consensus among the applied methods whereby up to 573 lake and river catchments are highly vulnerable to climate change. The anthropogenic disruption of hydrological habitat connectivity by dams is the major factor reducing climate change resilience. A gap analysis demonstrated that the current European protected area network covers climate change. Priority should be placed on enhancing stakeholder cooperation at the major basin scale towards preventing further degradation of freshwater ecosystems and maintaining connectivity among catchments. The catchments identified as most vulnerable to climate change provide preliminary targets for development of climate change conservation management and mitigation strategies. © 2017 John Wiley & Sons Ltd.

  3. Nesting season food habits of 4 species of Herons and Egrets at Lake Okeechobee, Florida

    Science.gov (United States)

    Smith, J.P.

    1997-01-01

    Based on the composition of nestling regurgitations collected during 3 breeding seasons, fish were the most important prey group for Great Egrets (Ardea alba: N = 200 nest-day samples; aggregate percent biomass [APB] = 73.4%), Snowy Egrets (Egretta thula: N = 115; APB = 91.4%), and Tricolored Herons (E. tricolor. N = 68; APB = 97.3%). For Little Blue Herons (E. caerulerr. N = 57), grass shrimp (Palaemoneles paludosus; APB = 39.7%) ranked higher in overall importance than all fishes combined (APB = 36.5%). Dietary overlap, as measured by Schoener's Similarity Index, was greatest between Snowy Egrets and Tricolored Herons (77%) and lowest between Tricolored Herons and Little Blue Herons (30%). Diet diversity, as measured by Shannon's Index, was highest for Great Egrets (2.04), intermediate for Snowy Egrets (1.71) and Tricolored Herons (1.68), and lowest for Little Blue Herons (1.60). Great Egrets ate a wider variety of fish species and sizes, especially larger fishes, and more crayfish than the other species. Little Blue Herons ate fewer fish and more grass shrimp and insects, and ate smaller forage fishes than Tricolored Herons but similar-sized fish as Snowy Egrets. The coarse-scale trophic composition of Snowy Egret and Tricolored Heron diets did not differ significantly, but Tricolored Herons ate larger forage fishes than Snowy Egrets. Pronounced interannual and intercolony variation in diet composition suggested that Great Egrets and Little Blue Herons switched prey types as hydrologic conditions and habitat availability changed. Conversely, lack of such variation suggested that Snowy Egrets and Tricolored Herons adjusted their foraging tactics to ensure contin-ued encounters with preferred prey despite changing habitat conditions. These results are generally consistent with other published data, help confirm some generalizations about foraging strategies and patterns of niche differentiation among these ecologically similar species, and have implications for

  4. E.N.V.I.R.H.O.M.. Bioaccumulation of radionuclides in situations of chronic exposure of ecosystems and members of the public; Progress Report 2 covering the period June 2003 - September 2005; E.N.V.I.R.H.O.M.. Bioaccumulation de radionucleides dans les situations de l'exposition chronique des ecosystemes et de membres du public; Rapport 2 couvrant la periode Juin 2003- Septembre 2005

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2005-07-01

    The main objective of E.N.V.I.R.H.O.M. is to better assess real effects caused by chronic exposure to low levels of radioactive contaminants. This includes for example consequences on nervous system, immunity or metabolisms, consequences on reproduction, consequences on feeding processes and consequences on ecosystem productivity. E.N.V.I.R.O.M. has set a priority on radionuclides that are suspected of accumulation in organisms., it has also a priority on radionuclides that act not only with gamma rays. The program was started in 2001 and uranium was chosen to test the methodology. The two first years of E.N.V.I.R.H.O.M. demonstrated clearly that a signal can be seen even as a consequence of moderate exposure. It was also found that some simplifying hypothesis may be false. For example the simple biokinetic model assuming that the result of a continuous feeding is equivalent to the convolution of successive punctual inputs is not always true. When the input is constant, it should involve a steady state following an increase. Instead of that, a decrease has been observed in some cases (rats, crayfish). The second two years period ( 2004-2005) used the same strategy in a larger scale. As regard biota, the list of test organisms was extended (daphnia, insects)and also the tested radionuclides (Se, Tc, Am). The list of studied functions was extended (behavior and sleep, neurotransmission, genomic effects, intestinal immune capacity, drug metabolism, vitamin D metabolism). The E.N.V.I.R.H.O.M. program is the main experimental part of a container program devoted to chronic risks. (N.C.)

  5. CASPIAN BIOLOGICAL RESOURCES

    Directory of Open Access Journals (Sweden)

    M. K. Guseynov

    2015-01-01

    Full Text Available Aim. We present the data on the biological resources of the Caspian Sea, based on the analysis of numerous scientific sources published between years of 1965 and 2011. Due to changes in various biotic and abiotic factors we find it important to discuss the state of the major groups of aquatic biocenosis including algae, crayfish, shrimp, pontogammarus, fish and Caspian seal. Methods. Long-term data has been analyzed on the biology and ecology of the main commercial fish stocks and their projected catches for qualitative and quantitative composition, abundance and biomass of aquatic organisms that make up the food base for fish. Results and discussion. It has been found that the widespread commercial invertebrates in the Caspian Sea are still poorly studied; their stocks are not identified and not used commercially. There is a great concern about the current state of the main commercial fish stocks of the Caspian Sea. A critical challenge is to preserve the pool of biological resources and the restoration of commercial stocks of Caspian fish. For more information about the state of the marine ecosystem in modern conditions, expedition on Caspian Sea should be carried out to study the hydrochemical regime and fish stocks, assessment of sturgeon stocks, as well as the need to conduct sonar survey for sprat stocks. Conclusions. The main condition for preserving the ecosystem of the Caspian Sea and its unique biological resources is to develop and apply environmentally-friendly methods of oil, issuing concerted common fisheries rules in various regions of theCaspian Sea, strengthening of control for sturgeon by all Caspian littoral states. The basic principle of the protection of biological resources is their rational use, based on the preservation of optimal conditions of their natural or artificial reproduction. 

  6. The Emerging Amphibian Fungal Disease, Chytridiomycosis: A Key Example of the Global Phenomenon of Wildlife Emerging Infectious Diseases.

    Science.gov (United States)

    Kolby, Jonathan E; Daszak, Peter

    2016-06-01

    The spread of amphibian chytrid fungus, Batrachochytrium dendrobatidis, is associated with the emerging infectious wildlife disease chytridiomycosis. This fungus poses an overwhelming threat to global amphibian biodiversity and is contributing toward population declines and extinctions worldwide. Extremely low host-species specificity potentially threatens thousands of the 7,000+ amphibian species with infection, and hosts in additional classes of organisms have now also been identified, including crayfish and nematode worms.Soon after the discovery of B. dendrobatidis in 1999, it became apparent that this pathogen was already pandemic; dozens of countries and hundreds of amphibian species had already been exposed. The timeline of B. dendrobatidis's global emergence still remains a mystery, as does its point of origin. The reason why B. dendrobatidis seems to have only recently increased in virulence to catalyze this global disease event remains unknown, and despite 15 years of investigation, this wildlife pandemic continues primarily uncontrolled. Some disease treatments are effective on animals held in captivity, but there is currently no proven method to eradicate B. dendrobatidis from an affected habitat, nor have we been able to protect new regions from exposure despite knowledge of an approaching "wave" of B. dendrobatidis and ensuing disease.International spread of B. dendrobatidis is largely facilitated by the commercial trade in live amphibians. Chytridiomycosis was recently listed as a globally notifiable disease by the World Organization for Animal Health, but few countries, if any, have formally adopted recommended measures to control its spread. Wildlife diseases continue to emerge as a consequence of globalization, and greater effort is urgently needed to protect global health.

  7. Effects of active conductance distribution over dendrites on the synaptic integration in an identified nonspiking interneuron.

    Directory of Open Access Journals (Sweden)

    Akira Takashima

    Full Text Available The synaptic integration in individual central neuron is critically affected by how active conductances are distributed over dendrites. It has been well known that the dendrites of central neurons are richly endowed with voltage- and ligand-regulated ion conductances. Nonspiking interneurons (NSIs, almost exclusively characteristic to arthropod central nervous systems, do not generate action potentials and hence lack voltage-regulated sodium channels, yet having a variety of voltage-regulated potassium conductances on their dendritic membrane including the one similar to the delayed-rectifier type potassium conductance. It remains unknown, however, how the active conductances are distributed over dendrites and how the synaptic integration is affected by those conductances in NSIs and other invertebrate neurons where the cell body is not included in the signal pathway from input synapses to output sites. In the present study, we quantitatively investigated the functional significance of active conductance distribution pattern in the spatio-temporal spread of synaptic potentials over dendrites of an identified NSI in the crayfish central nervous system by computer simulation. We systematically changed the distribution pattern of active conductances in the neuron's multicompartment model and examined how the synaptic potential waveform was affected by each distribution pattern. It was revealed that specific patterns of nonuniform distribution of potassium conductances were consistent, while other patterns were not, with the waveform of compound synaptic potentials recorded physiologically in the major input-output pathway of the cell, suggesting that the possibility of nonuniform distribution of potassium conductances over the dendrite cannot be excluded as well as the possibility of uniform distribution. Local synaptic circuits involving input and output synapses on the same branch or on the same side were found to be potentially affected under

  8. Integrated management of waterbirds: Beyond the conventional

    Science.gov (United States)

    Erwin, R.M.; Parsons, Katharine C.; Brown, Stephen C.; Erwin, R. Michael; Czech, Helen A.; Coulson, John C.

    2002-01-01

    Integrated waterbird management over the past few decades has implicitly referred to methods for managing wetlands that usually attempt to enhance habitat for taxonomic groups such as shorebirds and wading birds, in addition to waterfowl, the traditional focus group. Here I describe five elements of integration in management: taxonomic, spatial, temporal, population and habitat, and multiple-use management objectives. Spatial integration simply expands the scale of management concern. Rather than emphasizing management on a very limited number of impoundments or wetlands in small refuges or wildlife management areas, the vision is beginning to shift to connectivity within larger landscapes on the order of many square kilometers as telemetry data on daily and seasonal movements for many species become available. Temporal integration refers to the potential for either simultaneous management for waterbirds and commercial 'crops' (e.g., crayfish and rice) or for temporally-staggered management such as row crop production in spring-summer growing seasons and waterbird management on fallow fields in the non-growing (winter) season. Integrating population dynamics with habitats has become a major research focus over the past decade. Identifying which wetlands are ?sources? or ?sinks? for specific populations provides managers with critical information about effective management. Further, the applications of spatially explicit population models place heavy demands on researchers to identify use patterns for breeding and dispersing individuals by age, sex, and reproductive class. Population viability analysis models require much the same information. Finally, multiple-use management integration refers to trying to optimize the uses of wetlands, when only one (perhaps secondary) use may include waterbird management. Depending upon the ownership and primary land use of a particular parcel of land containing wetlands and/or water bodies, managing for waterbirds may be an

  9. Sodium channels as targets for volatile anesthetics

    Directory of Open Access Journals (Sweden)

    Karl F. Herold

    2012-03-01

    Full Text Available The molecular mechanisms of modern inhaled anesthetics although widely used in clinical settings are still poorly understood. Considerable evidence supports effects on membrane proteins such as ligand- and voltage-gated ion channels of excitable cells. Na+ channels are crucial to action potential initiation and propagation, and represent potential targets for volatile anesthetics. Inhibition of presynaptic Na+ channels leads to reduced neurotransmitter release at the synapse and could therefore contribute to the mechanisms by which volatile anesthetics produce their characteristic effects: amnesia, unconsciousness, and immobility. Early studies on crayfish and squid giant axon showed inhibition of Na+ currents by volatile anesthetics. Subsequent studies using native neuronal preparations and heterologous expression systems with various mammalian Na+ channel isoforms implicated inhibition of presynaptic Na+ channels in anesthetic actions. Volatile anesthetics reduce peak Na+ current and shift the voltage of half-maximal steady-state inactivation towards more negative potentials, thus stabilizing the fast-inactivated state. Furthermore recovery from fast-inactivation is slowed together with an enhanced use-dependent block during pulse train protocols. These effects can reduce neurotransmitter release by depressing presynaptic excitability, depolarization and Ca entry, and ultimately transmitter release. This reduction in transmitter release is more portent for glutamatergic vs. GABAergic terminals. Involvement of Na+ channel inhibition in mediating the immobility caused by volatile anesthetics has been demonstrated in animal studies, in which intrathecal infusion of the Na+ channel blocker tetrodotoxin increases volatile anesthetic potency, whereas infusion of the Na+ channels agonist veratridine reduces anesthetic potency. These studies indicate that inhibition of presynaptic Na+ channels by volatile anesthetics is involved in mediating some of

  10. Energy reserves mobilization: Strategies of three decapod species.

    Science.gov (United States)

    Sacristán, Hernán Javier; Rodríguez, Yamila Eliana; De Los Angeles Pereira, Nair; López Greco, Laura Susana; Lovrich, Gustavo Alejandro; Fernández Gimenez, Analía Verónica

    2017-01-01

    In food deprivation assays, several different responses have been observed in crustaceans. However, studying energy reserves utilization among more than one species during the same starvation period has not yet been performed, particularly to discern whether the responses are due to intrinsic and/or environmental factors. We hypothesize that decapod species with similar feeding habits have the same strategies in the use of energetic reserves during starvation, even though they inhabit different environments. The aim of this study was to compare the energy reserves mobilization of three decapods species (Cherax quadricarinatus, Palaemon argentinus and Munida gregaria) with similar feeding habits, exposed to similar food deprivation conditions. The crayfish, shrimp and squat-lobster were experimentally kept at continuous feeding or continuous starvation throughout 15 days. Every 3rd day, the midgut gland index (MGI), and the glycogen, lipid and protein contents were measured in the midgut gland (MG) and pleon muscle. Palaemon argentinus mobilized more reserves during starvation, followed by C. quadricarinatus, and the last M. gregaria. The starved shrimps presented low MGI, whereas MG showed a reduction in glycogen (from day 6 to 15), lipid (from day 3 to 15), and protein levels (at day 9 and 15) while in their muscle, lipid reserves decreased at days 3 and 6. In C. quadricarinatus, the most affected parameters in the MG were MGI, glycogen (from day 6 to 15), and lipids (at day 12 and 15). In the MG of M. gregaria only the glycogen was reduced during fasting from 3 to 15 days. Even though the three studied species have similar feeding habitats, we found that their energetic profile utilization is different and it could be explained by the habitat, life span, temperature, organ/tissue, and metabolism of the species. Our results may be useful to understand the several different responses of crustaceans during starvation.

  11. The influence of drought on flow‐ecology relationships in Ozark Highland streams

    Science.gov (United States)

    Lynch, Dustin T.; Leasure, D. R.; Magoulick, Daniel D.

    2018-01-01

    Drought and summer drying can have strong effects on abiotic and biotic components of stream ecosystems. Environmental flow‐ecology relationships may be affected by drought and drying, adding further uncertainty to the already complex interaction of flow with other environmental variables, including geomorphology and water quality.Environment–ecology relationships in stream communities in Ozark Highland streams, USA, were examined over two years with contrasting environmental conditions, a drought year (2012) and a flood year (2013). We analysed fish, crayfish and benthic macroinvertebrate assemblages using two different approaches: (1) a multiple regression analysis incorporating predictor variables related to habitat, water quality, geomorphology and hydrology and (2) a canonical ordination procedure using only hydrologic variables in which forward selection was used to select predictors that were most related to our response variables.Reach‐scale habitat quality and geomorphology were found to be the most important influences on community structure, but hydrology was also important, particularly during the flood year. We also found substantial between‐year variation in environment–ecology relationships. Some ecological responses differed significantly between drought and flood years, while others remained consistent. We found that magnitude was the most important flow component overall, but that there was a shift in relative importance from low flow metrics during the drought year to average flow metrics during the flood year, and the specific metrics of importance varied markedly between assemblages and years.Findings suggest that understanding temporal variation in flow‐ecology relationships may be crucial for resource planning. While some relationships show temporal variation, others are consistent between years. Additionally, different kinds of hydrologic variables can differ greatly in terms of which assemblages they affect and how they affect

  12. Predicting the Occurrence of Cave-Inhabiting Fauna Based on Features of the Earth Surface Environment.

    Science.gov (United States)

    Christman, Mary C; Doctor, Daniel H; Niemiller, Matthew L; Weary, David J; Young, John A; Zigler, Kirk S; Culver, David C

    2016-01-01

    One of the most challenging fauna to study in situ is the obligate cave fauna because of the difficulty of sampling. Cave-limited species display patchy and restricted distributions, but it is often unclear whether the observed distribution is a sampling artifact or a true restriction in range. Further, the drivers of the distribution could be local environmental conditions, such as cave humidity, or they could be associated with surface features that are surrogates for cave conditions. If surface features can be used to predict the distribution of important cave taxa, then conservation management is more easily obtained. We examined the hypothesis that the presence of major faunal groups of cave obligate species could be predicted based on features of the earth surface. Georeferenced records of cave obligate amphipods, crayfish, fish, isopods, beetles, millipedes, pseudoscorpions, spiders, and springtails within the area of Appalachian Landscape Conservation Cooperative in the eastern United States (Illinois to Virginia and New York to Alabama) were assigned to 20 x 20 km grid cells. Habitat suitability for these faunal groups was modeled using logistic regression with twenty predictor variables within each grid cell, such as percent karst, soil features, temperature, precipitation, and elevation. Models successfully predicted the presence of a group greater than 65% of the time (mean = 88%) for the presence of single grid cell endemics, and for all faunal groups except pseudoscorpions. The most common predictor variables were latitude, percent karst, and the standard deviation of the Topographic Position Index (TPI), a measure of landscape rugosity within each grid cell. The overall success of these models points to a number of important connections between the surface and cave environments, and some of these, especially soil features and topographic variability, suggest new research directions. These models should prove to be useful tools in predicting the

  13. A Lota lota consumption: Trophic dynamics of nonnative Burbot in a valuable sport fishery

    Science.gov (United States)

    Klobucar, Stephen L.; Saunders, W. Carl; Budy, Phaedra

    2016-01-01

    Unintentional and illegal introductions of species disrupt food webs and threaten the success of managed sport fisheries. Although many populations of Burbot Lota lota are declining in the species’ native range, a nonnative population recently expanded into Flaming Gorge Reservoir (FGR), Wyoming–Utah, and threatens to disrupt predator–prey interactions within this popular sport fishery. To determine potential impacts on sport fishes, especially trophy Lake Trout Salvelinus namaycush, we assessed the relative abundance of Burbot and quantified the potential trophic or food web impacts of this population by using diet, stable isotope, and bioenergetic analyses. We did not detect a significant potential for food resource competition between Burbot and Lake Trout (Schoener’s overlap index = 0.13), but overall consumption by Burbot likely affects other sport fishes, as indicated by our analyses of trophic niche space. Diet analyses suggested that crayfish were important diet items across time (89.3% of prey by weight in autumn; 49.4% in winter) and across Burbot size-classes (small: 77.5% of prey by weight; medium: 76.6%; large: 39.7%). However, overall consumption by Burbot increases as water temperatures cool, and fish consumption by Burbot in FGR was observed to increase during winter. Specifically, large Burbot consumed more salmonids, and we estimated (bioenergetically) that up to 70% of growth occurred in late autumn and winter. Further, our population-wide consumption estimates indicated that Burbot could consume up to double the biomass of Rainbow Trout Oncorhynchus mykiss stocked annually (>1.3 × 105 kg; >1 million individuals) into FGR. Overall, we provide some of the first information regarding Burbot trophic interactions outside of the species’ native range; these findings can help to inform the management of sport fisheries if Burbot range expansion occurs elsewhere.

  14. The technology of fish-vegetable feed production

    Directory of Open Access Journals (Sweden)

    Mukatova M. D.

    2016-09-01

    Full Text Available Perspective direction of the Volga-Caspian basin fisheries is increasing the productivity of aquaculture production which requires the availability of sufficient quantities of feed. The cutting waste of carp and crucian carp, crayfish processing (cephalothorax, wheat bran, soy isolate, freshwater plants – pondweed perfoliate, fish-vegetable ration, produced feeding staffs have been investigated. In researching samples of manufactured pelleted feeds the standard methods adopted in the animal feed industry have been used. The number of nitrogen-free extractives and energy value has been determined by calculation. The composition of fish-vegetable ration has been worked out. Some manufacturing inspection of fish-vegetable feed technology using proofing process has been carried out. The possibility of manufacturing on the basis of crushed fish waste of the company LLC "VES" and dry ingredients of fish-vegetable feed has been determined; the output of feed at water content of not more than 10 % is 43 % of feed mix based on the mass of directed waste equal to 84 %. The pilot batch of dry fish-vegetable feed has been investigated to establish quality indicators. It has been determined that fish-vegetable feed meets the requirements of GOST 10385–2014 "Combined feeding staffs for fishes. General specifications" as for main quality indicators and refers to economic grower for catfish and carp fish weighing more than 50 g. This reveals good palatability of the experimental batch of floating feed by carp fish species and African catfish. Thus, fish-vegetable feed manufacturing technology can be implemented in the production for processing secondary raw materials: waste from butchering fish by grinding, cooking, mixing with selected vegetable fillings which is waste of flour or grain processing industries and freshwater plants mowed annually during the reclamation works on the Volga delta.

  15. Mercury in fish from three rift valley lakes (Turkana, Naivasha and Baringo), Kenya, East Africa

    Energy Technology Data Exchange (ETDEWEB)

    Campbell, L.M.; Osano, O.; Hecky, R.E.; Dixon, D.G

    2003-09-01

    Mercury concentrations in Kenyan fish vary with tropic position but, in general, do not pose an unacceptable risk to human consumers of wildlife. -Total mercury (THg) concentrations were measured for various fish species from Lakes Turkana, Naivasha and Baringo in the rift valley of Kenya. The highest THg concentration (636 ng g{sup -1} wet weight) was measured for a piscivorous tigerfish Hydrocynus forskahlii from Lake Turkana. THg concentrations for the Perciformes species, the Nile perch Lates niloticus from Lake Turkana and the largemouth bass Micropterus salmoides from Lake Naivasha ranged between 4 and 95 ng g{sup -1}. The tilapiine species in all lakes, including the Nile tilapia Oreochromis niloticus, had consistently low THg concentrations ranging between 2 and 25 ng g{sup -1}. In Lake Naivasha, the crayfish species, Procambrus clarkii, had THg concentrations similar to those for the tilapiine species from the same lake, which is consistent with their shared detritivore diet. THg concentrations in all fish species were usually consistent with their known trophic position, with highest concentrations in piscivores and declining in omnivores, insectivores and detritivores. One exception is the detritivore Labeo cylindricus from Lake Baringo, which had surprisingly elevated THg concentrations (mean=75 ng g{sup -1}), which was similar to those for the top trophic species (Clarias and Protopterus) in the same lake. Except for two Hydrocynus forskahlii individuals from Lake Turkana, which had THg concentrations near or above the international marketing limit of 500 ng g{sup -1}, THg concentrations in the fish were generally below those of World Health Organization's recommended limit of 200 ng g{sup -1} for at-risk groups.

  16. The energetic contributions of aquatic primary producers to terrestrial food webs in a mid-size river system.

    Science.gov (United States)

    Kautza, Adam; Mazeika, S; Sullivan, P

    2016-03-01

    Rivers are increasingly recognized as providing nutritional subsidies (i.e., energy and nutrients) to adjacent terrestrial food webs via depredation of aquatic organisms (e.g., emergent aquatic insects, crayfish, fish) by terrestrial consumers. However, because these prey organisms assimilate energy from both aquatic (e.g., benthic algae, phytoplankton, aquatic macrophytes) and terrestrial (e.g., riparian leaf detritus) primary producers, river subsidies to terrestrial consumers represent a combination of aquatically and terrestrially derived energy. To date, the explicit contribution of energy derived from aquatic primary producers to terrestrial consumers has not been fully explored yet might be expected to be quantitatively important to terrestrial food webs. At 12 reaches along a 185-km segment of the sixth-order Scioto River system (Ohio, USA), we quantified the relative contribution of energy derived from aquatic primary producers to a suite of terrestrial riparian consumers that integrate the adjacent landscape across multiple spatial scales through their foraging activities (tetragnathid spiders, rove beetles, adult coenagrionid damselflies, riparian swallows, and raccoons). We used naturally abundant stable isotopes (13C and 15N) of periphyton, phytoplankton, macrophytes, and terrestrial vegetation to evaluate the energetic contribution of aquatic primary producers to terrestrial food webs. Shoreline tetragnathid spiders were most reliant on aquatic primary producers (50%), followed by wider-ranging raccoons (48%), damselflies (44%), and riparian swallows (41%). Of the primary producers, phytoplankton (19%) provisioned the greatest nutritional contribution to terrestrial consumers (considered collectively), followed by periphyton (14%) and macrophytes (11%). Our findings provide empirical evidence that aquatic primary producers of large streams and rivers can be a critical nutritional resource for terrestrial food webs. We also show that aquatically

  17. Growth, survival, longevity, and population size of the Big Mouth Cave salamander (Gyrinophilus palleucus necturoides) from the type locality in Grundy County, Tennessee, USA

    Science.gov (United States)

    Niemiller, Matthew L.; Glorioso, Brad M.; Fenolio, Dante B.; Reynolds, R. Graham; Taylor, Steven J.; Miller, Brian T.

    2016-01-01

    Salamander species that live entirely in subterranean habitats have evolved adaptations that allow them to cope with perpetual darkness and limited energy resources. We conducted a 26-month mark–recapture study to better understand the individual growth and demography of a population of the Big Mouth Cave Salamander (Gyrinophilus palleucus necturoides). We employed a growth model to estimate growth rates, age at sexual maturity, and longevity, and an open population model to estimate population size, density, detectability, and survival rates. Furthermore, we examined cover use and evidence of potential predation. Individuals probably reach sexual maturity in 3–5 years and live at least nine years. Survival rates were generally high (>75%) but declined during the study. More than 30% of captured salamanders had regenerating tails or tail damage, which presumably represent predation attempts by conspecifics or crayfishes. Most salamanders (>90%) were found under cover (e.g., rocks, trash, decaying plant material). Based on 11 surveys during the study, population size estimates ranged from 21 to 104 individuals in the ca. 710 m2 study area. Previous surveys indicated that this population experienced a significant decline from the early 1970s through the 1990s, perhaps related to silvicultural and agricultural practices. However, our data suggest that this population has either recovered or stabilized during the past 20 years. Differences in relative abundance between early surveys and our survey could be associated with differences in survey methods or sampling conditions rather than an increase in population size. Regardless, our study demonstrates that this population is larger than previously thought and is in no immediate risk of extirpation, though it does appear to exhibit higher rates of predation than expected for a species believed to be an apex predator of subterranean food webs.

  18. Vulnerability of intertropical littoral areas

    Science.gov (United States)

    Manighetti, Isabelle; De Wit, Rutger; Duvail, Stéphanie; Seyler, Patrick

    2017-10-01

    The coastal zone is of very high importance for human development and human wellbeing. Half of the global urban population lives in the coastal zone, where it has access to both continental and marine ecosystem services and to maritime transport. These urban populations coexist with rural and traditional coastal populations, some of which still possess good traditional ecological knowledge of the coastal ecosystems. Marine biodiversity and favourable environmental conditions sustain fisheries and aquaculture, represent a source of inspiration for humankind and provide numerous opportunities for recreation and tourism. In addition, coastal areas provide nursery functions for juvenile fish and invertebrates, which is important for the fish and crayfish stocks exploited offshore. Located at the interface between marine energy and continental processes, the coastal landscapes are dynamic environments. Nevertheless, the destruction of habitats and the increasing exploitation of the coastal zone represent serious threats to the ecosystems. Moreover, human land use and modifications in the watersheds have strong impacts on the coastal zone primarily by contributing to their pollution and nutrient over-enrichment. Damming and creation of reservoirs upstream also heavily modify the hydrology of the watersheds and often dramatically reduce the delivery of sediments to the coastal zone. In addition to these regional and local anthropogenic impacts, the coastal zone is vulnerable to global change among which sea level rise and climate change are particularly important drivers. Many coastal zones extend along giant faults and subduction zones, which makes them particularly exposed to earthquakes and tsunami hazards. Other forms of natural hazards are caused by hurricanes and cyclones that develop at sea and whose trajectories often hit the coastlines.

  19. One precursor, three apolipoproteins: the relationship between two crustacean lipoproteins, the large discoidal lipoprotein and the high density lipoprotein/β-glucan binding protein.

    Science.gov (United States)

    Stieb, Stefanie; Roth, Ziv; Dal Magro, Christina; Fischer, Sabine; Butz, Eric; Sagi, Amir; Khalaila, Isam; Lieb, Bernhard; Schenk, Sven; Hoeger, Ulrich

    2014-12-01

    The novel discoidal lipoprotein (dLp) recently detected in the crayfish, differs from other crustacean lipoproteins in its large size, apoprotein composition and high lipid binding capacity, We identified the dLp sequence by transcriptome analyses of the hepatopancreas and mass spectrometry. Further de novo assembly of the NGS data followed by BLAST searches using the sequence of the high density lipoprotein/1-glucan binding protein (HDL-BGBP) of Astacus leptodactylus as query revealed a putative precursor molecule with an open reading frame of 14.7 kb and a deduced primary structure of 4889 amino acids. The presence of an N-terminal lipid bind- ing domain and a DUF 1943 domain suggests the relationship with the large lipid transfer proteins. Two-putative dibasic furin cleavage sites were identified bordering the sequence of the HDL-BGBP. When subjected to mass spectroscopic analyses, tryptic peptides of the large apoprotein of dLp matched the N-terminal part of the precursor, while the peptides obtained for its small apoprotein matched the C-terminal part. Repeating the analysis in the prawn Macrobrachium rosenbergii revealed a similar protein with identical domain architecture suggesting that our findings do not represent an isolated instance. Our results indicate that the above three apolipoproteins (i.e HDL-BGBP and both the large and the small subunit of dLp) are translated as a large precursor. Cleavage at the furin type sites releases two subunits forming a heterodimeric dLP particle, while the remaining part forms an HDL-BGBP whose relationship with other lipoproteins as well as specific functions are yet to be elucidated.

  20. Natural origin arsenic in aquatic organisms from a deep oligotrophic lake under the influence of volcanic eruptions.

    Science.gov (United States)

    Juncos, Romina; Arcagni, Marina; Rizzo, Andrea; Campbell, Linda; Arribére, María; Guevara, Sergio Ribeiro

    2016-02-01

    Volcanic eruptions are recognized sources of toxic elements to freshwater, including arsenic (As). In order to study the short term changes in the bioaccumulation of naturally occurring As by aquatic organisms in Lake Nahuel Huapi (Argentina), located close to the Puyehue-Cordón Caulle volcanic complex (PCCVC), we described As concentrations at different trophic levels and food web transfer patterns in three sites of the lake prior to the last PCCVC eruption (June 2011), and compared As concentrations in biota before and after the eruption. The highest As concentrations and greater variations both between sites and position in the water column, were observed in phytoplankton (3.9-64.8 µg g(-1) dry weight, DW) and small zooplankton (4.3-22.3 µg g(-1) DW). The pattern of As accumulation in aquatic organisms (whole body or muscle) was: primary producers (phytoplankton) > scrapper mollusks (9.3-15.3 µg g(-1) DW) > filter feeding mollusks (5.4-15.6 µg g(-1) DW) > omnivorous invertebrates (0.4-9.2 µg g(-1) DW) > zooplankton (1.2-3.5 µg g(-1) DW) > fish (0.2-1.9 µg g(-1) DW). We observed As biodilution in the whole food web, and in salmonids food chains, feeding on fish prey; but biomagnification in the food chain of creole perch, feeding on benthic crayfish. The impact of the 2011 PCCVC eruption on the As levels of biota was more evident in pelagic-associated organisms (zooplankton and planktivorous fish), but only in the short term, suggesting a brief high bioavailability of As in water after ash deposition. In benthic organisms As variations likely responded to shift in diet due to coverage of the littoral zone with ashes. Copyright © 2015 Elsevier Ltd. All rights reserved.

  1. Use of aquaculture ponds and other habitats by autumn migrating shorebirds along the lower Mississippi river.

    Science.gov (United States)

    Lehnen, Sarah E; Krementz, David G

    2013-08-01

    Populations of many shorebird species are declining; habitat loss and degradation are among the leading causes for these declines. Shorebirds use a variety of habitats along interior migratory routes including managed moist soil units, natural wetlands, sandbars, and agricultural lands such as harvested rice fields. Less well known is shorebird use of freshwater aquaculture facilities, such as commercial cat- and crayfish ponds. We compared shorebird habitat use at drained aquaculture ponds, moist soil units, agricultural areas, sandbars and other natural habitat, and a sewage treatment facility in the in the lower Mississippi River Alluvial Valley (LMAV) during autumn 2009. Six species: Least Sandpiper (Calidris minutilla), Killdeer (Charadrius vociferous), Semipalmated Sandpiper (Calidris pusilla), Pectoral Sandpiper (C. melanotos), Black-necked Stilt (Himantopus himantopus), and Lesser Yellowlegs (Tringa flavipes), accounted for 92 % of the 31,165 individuals observed. Sewage settling lagoons (83.4, 95 % confidence interval [CI] 25.3-141.5 birds/ha), drained aquaculture ponds (33.5, 95 % CI 22.4-44.6 birds/ha), and managed moist soil units on public lands (15.7, CI 11.2-20.3 birds/ha) had the highest estimated densities of shorebirds. The estimated 1,100 ha of drained aquaculture ponds available during autumn 2009 provided over half of the estimated requirement of 2,000 ha by the LMAV Joint Venture working group. However, because of the decline in the aquaculture industry, autumn shorebird habitats in the LMAV may be limited in the near future. Recognition of the current aquaculture habitat trends will be important to the future management activities of federal and state agencies. Should these aquaculture habitat trends continue, there may be a need for wildlife biologists to investigate other habitats that can be managed to offset the current and expected loss of aquaculture acreages. This study illustrates the potential for freshwater aquaculture to

  2. Periodically-modulated inhibition of living pacemaker neurons--III. The heterogeneity of the postsynaptic spike trains, and how control parameters affect it.

    Science.gov (United States)

    Segundo, J P; Vibert, J F; Stiber, M

    1998-11-01

    Codings involving spike trains at synapses with inhibitory postsynaptic potentials on pacemakers were examined in crayfish stretch receptor organs by modulating presynaptic instantaneous rates periodically (triangles or sines; frequencies, slopes and depths under, respectively, 5.0 Hz, 40.0/s/s and 25.0/s). Timings were described by interspike and cross-intervals ("phases"); patterns (dispersions, sequences) and forms (timing classes) were identified using pooled graphs (instant along the cycle when a spike occurs vs preceding interval) and return maps (plots of successive intervals). A remarkable heterogeneity of postsynaptic intervals and phases characterizes each modulation. All cycles separate into the same portions: each contains a particular form and switches abruptly to the next. Forms differ in irregularity and predictability: they are (see text) "p:q alternations", "intermittent", "phase walk-throughs", "messy erratic" and "messy stammering". Postsynaptic cycles are asymmetric (hysteresis). This contrasts with the presynaptic homogeneity, smoothness and symmetry. All control parameters are, individually and jointly, strongly influential. Presynaptic slopes, say, act through a postsynaptic sensitivity to their magnitude and sign; when increasing, hysteresis augments and forms change or disappear. Appropriate noise attenuates between-train contrasts, providing modulations are under 0.5 Hz. Postsynaptic natural intervals impose critical time bases, separating presynaptic intervals (around, above or below them) with dissimilar consequences. Coding rules are numerous and have restricted domains; generalizations are misleading. Modulation-driven forms are trendy pacemaker-driven forms. However, dissimilarities, slight when patterns are almost pacemaker, increase as inhibition departs from pacemaker and incorporate unpredictable features. Physiological significance-(1) Pacemaker-driven forms, simple and ubiquitous, appear to be elementary building blocks of

  3. Hydropedological model of vertisol formation along the Gulf Coast Prairie land resource area of Texas

    Directory of Open Access Journals (Sweden)

    S. G. Driese

    2009-11-01

    Full Text Available Vertisols are clayey soils containing slickensides and wedge-shaped aggregates formed by shrink-swell processes in seasonally wet climates. The dynamic distribution of macro- and microvoids as a by-product of this unique pedoturbation process, accompanied by microtopographic lows and highs (gilgai, mitigate our ability to make accurate and precise interpretations of aquic and hydric conditions in these problem soils. We studied Vertisols across a subhumid to humid climosequence to assess the formation of redoximorphic features on shallow, linear (nondepressional landscape positions in response to varying levels of rainfall. Approximately 1000 mm of mean annual precipitation (MAP is required to form soft iron masses that then increase in abundance, and to shallower depths, with increasing rainfall. Soft iron masses with diffuse boundaries become more abundant with higher rainfall in microlows, whereas masses with nondiffuse boundaries become more common in microhighs. Most soft iron masses form in oxygenated ped interiors as water first saturates and then reduces void walls where iron depletions form. In contrast, at least 1276 mm of MAP is needed to form iron pore linings in both microlow and microhigh topographic positions. Iron depletions do not correlate with rainfall in terms of abundance or depth of occurrence. The quantity of crayfish burrows co-varies with rainfall and first appears coincidentally with soft iron masses in microlows near 1000 mm of MAP; they do not appear until nearly 1400 mm of MAP in microhighs. Dithionite-citrate extractable and ammonium-oxalate extractable iron oxides increase systematically with rainfall indicating more frequent episodes of iron reduction and precipitation into pedogenic segregations. The sum of our data suggests that Vertisols forming in the Coast Prairie of Texas with MAP greater than 1276 mm should be classified as aquerts because of the presence of aquic conditions. These same soils may also meet

  4. Red Tide Strands South African Rock Lobsters

    Science.gov (United States)

    2002-01-01

    Although some red tides form a healthy part of phytoplankton production, recurrent harmful or toxic blooms also occur, with results depending upon the type of plankton and on atmospheric and oceanic conditions. At Elands Bay in South Africa's Western Cape province, about 1000 tons of rock lobsters beached themselves during February 2002, when the decay of dense blooms of phytoplankton caused a rapid reduction in the oxygen concentration of nearshore waters. The lobsters (or crayfish, as they are known locally) moved toward the breaking surf in search of oxygen, but were stranded by the retreating tide. The Multi-angle Imaging SpectroRadiometer's nadir camera acquired these red, green, blue composites on February 2 and 18, 2002, during Terra orbits 11315 and 11548. The colors have been accentuated to highlight the bloom, and land and water have been enhanced separately. The two views show the shoreward migration of the algal bloom. Each image represents an area of about 205 kilometers x 330 kilometers. Elands Bay is situated near the mouth of the Doring River, about 75 kilometers northeast of the jutting Cape Columbine. The term 'red tide' is used to refer to a number of different types of phytoplankton blooms of various hues. The wine color of certain parts of this bloom are consistent with the ciliate species Mesodinium rubrum, which has been associated with recurring harmful algal blooms along the Western Cape coast. Under these conditions, the lobsters are not poisoned. During the recent event, government and military staff transported as many of the living lobsters as possible to areas that were less affected by the red tide. At the same time, people came from across South Africa to gather the undersized creatures for food. The effects of the losses on the maritime economy are expected to be felt over the next few years. MISR was built and is managed by NASA's Jet Propulsion Laboratory, Pasadena, CA, for NASA's Office of Earth Science, Washington, DC. The Terra

  5. Hydropedological model of vertisol formation along the Gulf Coast Prairie land resource area of Texas

    Science.gov (United States)

    Nordt, L. C.; Driese, S. G.

    2009-11-01

    Vertisols are clayey soils containing slickensides and wedge-shaped aggregates formed by shrink-swell processes in seasonally wet climates. The dynamic distribution of macro- and microvoids as a by-product of this unique pedoturbation process, accompanied by microtopographic lows and highs (gilgai), mitigate our ability to make accurate and precise interpretations of aquic and hydric conditions in these problem soils. We studied Vertisols across a subhumid to humid climosequence to assess the formation of redoximorphic features on shallow, linear (nondepressional) landscape positions in response to varying levels of rainfall. Approximately 1000 mm of mean annual precipitation (MAP) is required to form soft iron masses that then increase in abundance, and to shallower depths, with increasing rainfall. Soft iron masses with diffuse boundaries become more abundant with higher rainfall in microlows, whereas masses with nondiffuse boundaries become more common in microhighs. Most soft iron masses form in oxygenated ped interiors as water first saturates and then reduces void walls where iron depletions form. In contrast, at least 1276 mm of MAP is needed to form iron pore linings in both microlow and microhigh topographic positions. Iron depletions do not correlate with rainfall in terms of abundance or depth of occurrence. The quantity of crayfish burrows co-varies with rainfall and first appears coincidentally with soft iron masses in microlows near 1000 mm of MAP; they do not appear until nearly 1400 mm of MAP in microhighs. Dithionite-citrate extractable and ammonium-oxalate extractable iron oxides increase systematically with rainfall indicating more frequent episodes of iron reduction and precipitation into pedogenic segregations. The sum of our data suggests that Vertisols forming in the Coast Prairie of Texas with MAP greater than 1276 mm should be classified as aquerts because of the presence of aquic conditions. These same soils may also meet the definition of

  6. High-Functioning Wetland Formed Atop Abandoned Pavement in Eutrophic Reservoir Watershed

    Science.gov (United States)

    Clifford, C.; Heffernan, J. B.

    2017-12-01

    Water scientists and managers regularly observe how wetlands, whether natural or created, can mitigate the influence of artificial impervious surfaces on water quality. However, we rarely study or mention wetlands accidentally (sensu Palta et al. 2017) formed atop impervious surfaces. This silence occurs even though many urbanites have likely noticed sedges rimming a clogged drainage grate or in the low bits of a poorly graded or aging parking lot, or similar. A more extreme example occurs in the Little River Waterfowl Impoundment vicinity of the Butner-Falls of Neuse Game Land in Durham, North Carolina. There, a macadam road that connected local residents and a store, and served as the primary route through the area, by 1910-1920, was apparently abandoned by 1951. Later, damming nearby downstream Falls Lake Reservoir in 1981, and smaller-scale construction locally, apparently increased water table depth and flow exposure. Yet, the road remains largely intact structurally, though mostly buried and sometimes underwater. In a particularly wet segment of the road, surrounded by and partially holding back standing water even in drought, a substantial, mostly native wetland plant community has formed. This community includes trees such as overcup oak (Quercus lyrata) as large as 15 cm in diameter, shrubs such as (Cephalanthus occidentalus), sedges such as woolgrass (Scirpus cyperinus), rushes (multiple Juncus species), grasses such as wood oats (Chasmanthium latifolium), crayfish and fish, and multiple orders of herptiles. The plants grow rooted in fluffy sediment three to rarely more than 20cm deep, over solid pavement. Alongside the old road, the ditches have widened and become shallower and less surficially connected through tree roots and debris dams; they resemble pools. Sediment in these abandoned ditches has accumulated to depths of tens of centimeters, generally reforming a clay-dominated, gleyed soil, in some places buried under more tens of centimeters of very

  7. Characterization of white shrimp Litopenaeus vannamei integrin β and its role in immunomodulation by dsRNA-mediated gene silencing.

    Science.gov (United States)

    Lin, Yong-Chin; Chen, Jiann-Chu; Chen, Yu-Yuan; Liu, Chun-Hung; Cheng, Winton; Hsu, Chih-Hung; Tsui, Wen-Ching

    2013-06-01

    The full sequence of white shrimp Litopenaeus vannamei integrin β (LV-B) is 2879bp which encodes 787 amino acids (aa) of the open reading frame (ORF). The mature protein (764 aa) contains (1) an extracellular domain (ED) of 692 aa, (2) a transmembrane domain (TD) of 23 aa, and (3) a cytoplasmic domain (CD) of 49 aa. The cloned LV-B grouped together with crayfish Pacifastacus leniusculus integrin β (PL-B1), but was far away from vertebrate integrin β1, β3, β5, β6, β7, and β8, and another L. vannamei integrin β (LV). A Southern blot analysis indicated that the cloned LV-B was a single copy of genomic DNA. LV-B mRNA was expressed in all tissues, and was highly expressed in haemocytes. LV-B was downregulated in shrimp 24 and 96h after having received white spot syndrome virus (WSSV). LV-B expression by haemocytes of shrimp was higher in the postmoult (A and B) stage, and lower in the premoult (D2/D3) stage. LV-B expression was significantly higher by shrimp reared in 2.5‰ and 5‰ salinities. Shrimp injected with integrin β dsRNA showed gene silencing of integrin β after 36h. LV-B-silenced shrimp showed decreased hyaline cells (HCs), granular cells (GCs, including semi-granular cells), the total haemocyte count (THC), respiratory bursts (RBs), and lysozyme activity, but showed increased RB/HC, superoxide dismutase (SOD) activity/HC, and the phenoloxidase (PO) activity/GC. LV-B-silenced shrimp showed upregulated expressions of lipopolysaccharide- and β-glucan-binding protein (LGBP), peroxinectin (PX), prophenoloxidase I (proPO I), proPO II, proPO-activating enzyme (ppA), α2-macroglobulin (α2-M), cytMnSOD, mtMnSOD, and heat shock protein 70 (HSP70). It was concluded that integrin β plays important roles in proPO activation, phagocytosis, and the antioxidant system for immunomodulation in shrimp. Copyright © 2013 Elsevier Ltd. All rights reserved.

  8. Influence of a chlor-alkali superfund site on mercury bioaccumulation in periphyton and low-trophic level fauna

    Science.gov (United States)

    Buckman, Kate L.; Marvin-DiPasquale, Mark C.; Taylor, Vivien F.; Chalmers, Ann T.; Broadley, Hannah J.; Agee, Jennifer L.; Jackson, Brian P.; Chen, Celia Y.

    2015-01-01

    In Berlin, New Hampshire, USA, the Androscoggin River flows adjacent to a former chlor-alkali facility that is a US Environmental Protection Agency Superfund site and source of mercury (Hg) to the river. The present study was conducted to determine the fate and bioaccumulation of methylmercury (MeHg) to lower trophic-level taxa in the river. Surface sediment directly adjacent to the source showed significantly elevated MeHg (10–40× increase, mean ± standard deviation [SD]: 20.1 ± 24.8 ng g–1 dry wt) and total mercury (THg; 10–30× increase, mean ± SD: 2045 ± 2669 ng g–1 dry wt) compared with all other reaches, with sediment THg and MeHg from downstream reaches elevated (3–7× on average) relative to the reference (THg mean ± SD: 33.5 ± 9.33 ng g–1 dry wt; MeHg mean ± SD: 0.52 ± 0.21 ng g–1 dry wt). Water column THg concentrations adjacent to the point source for both particulate (0.23 ng L–1) and dissolved (0.76 ng L–1) fractions were 5-fold higher than at the reference sites, and 2-fold to 5-fold higher than downstream. Methylmercury production potential of periphyton material was highest (2–9 ng g–1 d–1 dry wt) adjacent to the Superfund site; other reaches were close to or below reporting limits (0. 1 ng g–1 d–1 dry wt). Total Hg and MeHg bioaccumulation in fauna was variable across sites and taxa, with no clear spatial patterns downstream of the contamination source. Crayfish, mayflies, and shiners showed a weak positive relationship with porewater MeHg concentration.

  9. Physiological responses of Daphnia pulex to acid stress

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    Pirow Ralph

    2009-04-01

    Full Text Available Abstract Background Acidity exerts a determining influence on the composition and diversity of freshwater faunas. While the physiological implications of freshwater acidification have been intensively studied in teleost fish and crayfish, much less is known about the acid-stress physiology of ecologically important groups such as cladoceran zooplankton. This study analyzed the extracellular acid-base state and CO2 partial pressure (PCO2, circulation and ventilation, as well as the respiration rate of Daphnia pulex acclimated to acidic (pH 5.5 and 6.0 and circumneutral (pH 7.8 conditions. Results D. pulex had a remarkably high extracellular pH of 8.33 and extracellular PCO2 of 0.56 kPa under normal ambient conditions (pH 7.8 and normocapnia. The hemolymph had a high bicarbonate concentration of 20.9 mM and a total buffer value of 51.5 meq L-1 pH-1. Bicarbonate covered 93% of the total buffer value. Acidic conditions induced a slight acidosis (ΔpH = 0.16–0.23, a 30–65% bicarbonate loss, and elevated systemic activities (tachycardia, hyperventilation, hypermetabolism. pH 6.0 animals partly compensated the bicarbonate loss by increasing the non-bicarbonate buffer value from 2.0 to 5.1 meq L-1 pH-1. The extracellular PCO2 of pH 5.5 animals was significantly reduced to 0.33 kPa, and these animals showed the highest tolerance to a short-term exposure to severe acid stress. Conclusion Chronic exposure to acidic conditions had a pervasive impact on Daphnia's physiology including acid-base balance, extracellular PCO2, circulation and ventilation, and energy metabolism. Compensatory changes in extracellular non-bicarbonate buffering capacity and the improved tolerance to severe acid stress indicated the activation of defense mechanisms which may result from gene-expression mediated adjustments in hemolymph buffer proteins and in epithelial properties. Mechanistic analyses of the interdependence between extracellular acid-base balance and CO2 transport

  10. Factors affecting food chain transfer of mercury in the vicinity of the Nyanza site, Sudbury River, Massachusetts

    Science.gov (United States)

    Haines, T.A.; May, T.W.; Finlayson, R.T.; Mierzykowski, S.E.

    2003-01-01

    The influence of the Nyanza Chemical Waste Dump Superfund Site on the Sudbury River, Massachusetts, was assessed by analysis of sediment, fish prey organisms, and predator fish from four locations in the river system. Whitehall Reservoir is an impoundment upstream of the site, and Reservoir #2 is an impoundment downstream of the site. Cedar Street is a flowing reach upstream of the site, and Sherman Bridge is a flowing reach downstream of the site. Collections of material for analysis were made three times, in May, July, and October. Sediment was analyzed for acid-volatile sulfide (AVS), simultaneously-extracted (SEM) metals (As, Cd, Cr, Hg, Pb, Sb, Zn), and total recoverable Hg. The dominant predatory fish species collected at all sites, largemouth bass (Micropterus salmoides), was analyzed for the same suite of metals as sediment. Analysis of stomach contents of bass identified small fish (yellow perch Perca flavescens, bluegill Lepomis macrochirus, and pumpkinseed Lepomis gibbosus), crayfish, and dragonfly larvae as the dominant prey organisms. Samples of the prey were collected from the same locations and at the same times as predator fish, and were analyzed for total and methyl mercury. Results of AVS and SEM analyses indicated that sediments were not toxic to aquatic invertebrates at any site. The SEM concentrations of As, Cd, and Cr were significantly higher at Reservoir #2 than at the reference sites, and SEM As and Cd were significantly higher at Sherman Bridge than at Cedar St. Sediment total Hg was elevated only at Reservoir #2. Hg was higher at site-influenced locations in all fish species except brown bullhead (Ameiurus nebulosus). Cd was higher in bluegill, black crappie (Pomoxis nigromaculatus), and brown bullhead, and Cr was higher in largemouth bass fillet samples but not in whole-body samples. There were no seasonal differences in sediment or prey organism metals, but some metals in some fish species did vary over time in an inconsistent manner

  11. Urban malaria transmission in Buenaventura, Colombia: entomologic aspects Transmisión de la malaria urbana en Buenaventura, Colombia: aspectos entomológicos

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    Víctor Olano

    1997-12-01

    Full Text Available In recent years, the number of cases of urban malaria in Buenaventura, Colombia, has increased, rising from 576 in 1987 to 3296 in 1991 and 2017 in 1992. For this reason, an epidemiologic study to identify malaria transmission patterns was carried out in this municipality on Colombia’s Pacific coast. This article describes the entomologic findings regarding the vectors, their breeding sites, and the behavior of Anopheles species during the period from June 1993 to May 1994. Of the 469 potential breeding sites identified in the urban area, 28 were positive for anophelines, while in neighboring zones 20 out of 80 potential breeding sites were positive for the immature forms of these mosquitoes. Mining excavations, lakes, and commercial fish and crayfish rearing ponds were the places where A. albimanus was most frequently found. For A. nuñeztovari, the breeding sites were rain puddles and aquiculture ponds. A. neivai larvae were collected from bromeliads. Mosquitoes were collected both inside and outside houses, and 90% of the collected mosquitoes were identified as A. albimanus. Of the female A. albimanus, 54.8% were parous. This species was found to have peak peridomiciliary activity between 6 p.m. and 10 p.m. The highest biting rate outside houses was 7.1 bites per person-hour and was observed during March. It is hoped that this entomologic information will permit the launching of a strong community participation process and the implementation of control measures that are guided by these results.En los últimos años, el número de casos de malaria urbana en Buenaventura, Colombia, ha aumentado de 576 en 1987 a 3296 en 1991 y 2017 en 1992, por lo que se desarrolló un estudio epidemiológico para identificar patrones de transmisión de la malaria en este municipio del litoral pacífico colombiano. Se describen los hallazgos entomológicos en relación con los vectores, los criaderos y el comportamiento de las especies de Anopheles durante el

  12. Environmental Factors Affecting Mercury in Camp Far West Reservoir, California, 2001-03

    Science.gov (United States)

    Alpers, Charles N.; Stewart, A. Robin; Saiki, Michael K.; Marvin-DiPasquale, Mark C.; Topping, Brent R.; Rider, Kelly M.; Gallanthine, Steven K.; Kester, Cynthia A.; Rye, Robert O.; Antweiler, Ronald C.; De Wild, John F.

    2008-01-01

    water were observed in samples collected during summer from deepwater stations in the anoxic hypolimnion. In the shallow (less than 14 meters depth) oxic epilimnion, concentrations of methylmercury in unfiltered water were highest during the spring and lowest during the fall. The ratio of methylmercury to total mercury (MeHg/HgT) increased systematically from winter to spring to summer, largely in response to the progressive seasonal decrease in total mercury concentrations, but also to some extent because of increases in MeHg concentrations during summer. Water-quality data for Camp Far West Reservoir are used in conjunction with data from linked studies of sediment and biota to develop and refine a conceptual model for mercury methylation and bioaccumulation in the reservoir and the lower Bear River watershed. It is hypothesized that MeHg is produced by sulfate-reducing bacteria in the anoxic parts of the water column and in shallow bed sediment. Conditions were optimal for this process during late summer and fall. Previous work has indicated that Camp Far West Reservoir is a phosphate-limited system - molar ratios of inorganic nitrogen to inorganic phosphorus in filtered water were consistently greater than 16 (the Redfield ratio), sometimes by orders of magnitude. Therefore, concentrations of orthophosphate were expectedly very low or below detection at all stations during all seasons. It is further hypothesized that iron-reducing bacteria facilitate release of phosphorus from iron-rich sediments during summer and early fall, stimulating phytoplankton growth in the fall and winter, and that the MeHg produced in the hypolimnion and metalimnion is released to the entire water column in the late fall during reservoir destratification (vertical mixing). Mercury bioaccumulation factors (BAF) were computed using data from linked studies of biota spanning a range of trophic position: zooplankton, midge larvae, mayfly nymphs, crayfish, threadfin shad, bluegill,

  13. Vascular Plant and Vertebrate Inventory of Tumacacori National Historical Park

    Science.gov (United States)

    Powell, Brian F.; Albrecht, Eric W.; Halvorson, William L.; Schmidt, Cecilia A.; Anning, Pamela; Docherty, Kathleen

    2005-01-01

    Executive Summary This report summarizes the results of the first comprehensive biological inventory of Tumacacori National Historical Park (NHP) in southern Arizona. These surveys were part of a larger effort to inventory vascular plants and vertebrates in eight National Park Service units in Arizona and New Mexico. From 2000 to 2003 we surveyed for vascular plants and vertebrates (fish, amphibians, reptiles, birds, and mammals) at Tumacacori NHP to document presence of species within the administrative boundaries of the park's three units. Because we used repeatable study designs and standardized field techniques, these inventories can serve as the first step in a long-term monitoring program. We recorded 591 species at Tumacacori NHP, significantly increasing the number of known species for the park (Table 1). Species of note in each taxonomic group include: * Plants: second record in Arizona of muster John Henry, a non-native species that is ranked a 'Class A noxious weed' in California; * Amphibian: Great Plains narrow-mouthed toad; * Reptiles: eastern fence lizard and Sonoran mud turtle; * Birds: yellow-billed cuckoo, green kingfisher, and one observation of the endangered southwestern willow flycatcher; * Fishes: four native species including an important population of the endangered Gila topminnow in the Tumacacori Channel; * Mammals: black bear and all four species of skunk known to occur in Arizona. We recorded 79 non-native species (Table E.S.1), many of which are of management concern, including: Bermudagrass, tamarisk, western mosquitofish, largemouth bass, bluegill, sunfish, American bullfrog, feral cats and dogs, and cattle. We also noted an abundance of crayfish (a non-native invertebrate). We review some of the important non-native species and make recommendations to remove them or to minimize their impacts on the native biota of the park. Based on the observed species richness, Tumacacori NHP possesses high biological diversity of plants, fish

  14. Methods development for cost-effective marine environmental monitoring at offshore wind farms in Norwegian waters

    Energy Technology Data Exchange (ETDEWEB)

    Dahlgren, Thomas; Schlaeppy, Marie-Lise; Olenin, Sergej; Shashkov, Alexej; Heggoey, Erling; Troedsson, Christofer

    2011-07-01

    present (rocky seabed, sand, gravel and stones) and are often exposed to severe waves and strong tidal currents. Keystone organisms at an exposed and complex hard bottom environment can potentially include large kelp species (Laminaria), red algae growing on bare rock (e.g. Lithothamnion) and reef or bed forming species such as the horse mussel (Modiolus modiolus) and maerl (coralline algae). These structure-forming organisms support a high diversity of marine life and provide important ecosystem services such as feeding grounds for commercially valuable fish and crayfish species. No studies have so far investigated the effects from large-scale offshore wind farms in this type of environment. The first year of benthic marine baseline data collection in the Havsul area, suggested that there is a lack of standards for monitoring methods at complex marine habitats dominated by bare rock, and kelp communities. We have applied a suite of methods chosen to detect changes in a range of habitats and trophic levels including traditional sediment coring, metagenomic diversity estimates, video data collection and assessment of the kelp community. Preliminary results suggest that it is necessary to adjust monitoring practises to the local environment. This makes comparisons with other regions difficult and may jeopardise efforts to conduct studies of potential cumulative impacts. Benthic community structure assessments and large scale habitat mapping based on video mosaic data is particularly promising both in terms of cost effective collection of data, data quality and sensitivity. (Author)

  15. KANDUNGAN VITAMIN B6, B9, B12 DAN E BEBERAPA JENIS DAGING, TELUR, IKAN DAN UDANG LAUT DI BOGOR DAN SEKITARNYA (VITAMIN B6, B9, B12 AND E CONTENT OF SEVERAL TYPES OF MEATS, EGGS, FISHES AND MARINE SHRIMPS IN BOGOR AND SURROUNDING AREAS

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    Heru Yuniati

    2012-06-01

    Full Text Available ABSTRACT Food Composition Table (DKBM in Indonesia has not mentioned all types of nutrients available in the food, particularly vitamin B6, B9 (folic acid, B12, and vitamin E. Therefore this study aimed to analyze the content of vitamin B6, B9 (folic acid, B12, and vitamin E in several types of meat, eggs, fish and marine shrimps consumed in Bogor and surrounding areas. Vitamin B6, B9, B12, and vitamin E from three kinds of meat (chicken, beef, lamb, two types of eggs (chicken, duck, and four species of fish (snapper, bloating, carp and tuna and crayfish are analyzed using High-Performance Liquid Chromatography (HPLC. The samples used are raw and taken from three locations in Bogor and surrounding areas. Fishes, meats and eggs contain high levels of folic acid, however the amount of folic acid content in meat varies depending on which part of meat the samples are taken, types of organ, and the fat content of the meat. The folic acid content in chicken wings is different with those in thigh. In fatty mutton the folic acid is higher than in those lean meat, and in yolk is higher than those in egg white. Vitamin E content of snapper is the highest amongs other types of fishes (6.54 µg/100 g.Chicken eggs contain a higher amount of vitamin E than duck eggs, while the yolk contains ahigher amount of vitamin E than those egg white. Keywords: animal foods, vitamin B6, vitamin B9 (folic Acid, vitamin B12, vitamin E   ABSTRAK Daftar Komposisi Bahan Makanan (DKBM yang ada di Indonesia belum memuat semua jenis zat gizi dalam makanan, khususnya vitamin B6, B9 (asam folat, B12 dan vitamin E. Menganalisis kandungan vitamin B6, B9 (asam folat, B12, dan vitamin E dalam beberapa jenis daging, telur, ikan dan udang laut yang dikonsumsi masyarakat di Bogor dan sekitarnya. Kandungan vitamin B6, B9, B12 dan vitamin E dari tiga jenis daging (ayam, sapi, kambing, dua jenis telur (ayam, itik, serta empat jenis ikan (kakap, kembung, mas, tongkol dan udang laut

  16. EDITORIAL

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    Juan Antonio Villanueva Jiménez

    2012-11-01

    Full Text Available This special issue of Tropical and Subtropical Agroecosystems presents a selection of the scientific work conducted in recent years in the state of Veracruz, Mexico, associated with its agroecosystems, considering in a wide sense the term “ager” (field. Reviewing research carried out in a defined territory, such as a state, on its contrasting and sometimes complementary productive systems, allows us to visualize the topics on development by its scientific community frequently associated with the problems of a productive chain, the lack of sustainability, contamination affecting the regions and their living beings, the impacts of socioeconomic problems on food production and productivity. In this particular case livestock-related topics dealing with the yield of forages used for cattle grazing are revised, as well as epidemiological and animal-health aspects referring to the presence of paratuberculosis in goats and cryptosporidiosis in calves. As for agricultural aspects, biofertilization with rhizobacteria and mycorrhizal fungi in citrus is presented as an alternative to traditional fertilization; in the case of papaya, the integrated management of its pest mites as well as a participatory methodology to achieve its technological transfer are revised. In addition, the influence that human migration has on the change of land use in a mountain range community is presented, and the eating habits related with the potential practice of horticulture in peri-urban families from the subhumid tropics are revised. Some aquacultural elements are also included, such as the presence of parasitic microorganisms in the oyster depending on the season of the year, the cultivation of tilapia fry in water recirculation systems, basic studies on the genetic improvement of the crayfish, as well as the establishment of a hydroponic-aquaponic system where cultivation of basil and production of Malaysian prawn are combined. As for varied topics, the impact