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Sample records for goby pomatoschistus marmoratus

  1. Genetic architecture of the marbled goby Pomatoschistus marmoratus (Perciformes, Gobiidae) in the Mediterranean Sea.

    Science.gov (United States)

    Mejri, Randa; Arculeo, Marco; Hassine, Oum Kalthoum Ben; Brutto, Sabrina Lo

    2011-02-01

    The marbled goby Pomatoschistus marmoratus, a species inhabiting coastal Mediterranean lagoons, has been studied by measuring its mitochondrial DNA variation. This analysis revealed a Mediterranean west vs east split and, subsequently, an eastern differentiation among the Libyan-Tunisian Gulf, the Adriatic Sea and the Aegean Sea. The high cohesion between the samples collected in the vast area of western Mediterranean contrasts with the genetic mosaic of the more sub-structured eastern Mediterranean. This western homogeneity can not yet be fully explained even if a human-mediated migratory flow, due to a maritime traffic, has been posited. The pattern in the eastern basin revealed a genetic architecture possibly due to the non-migratory habit of the gobid. Within this perspective, the role of the Mediterranean lagoon habitat should be related to how much it amplifies the effects of historical (e.g. past sea-level changes) and environmental (e.g. present-day hydrographic regime) processes as regards the genetic structure of the inhabiting species. Copyright © 2010 Elsevier Inc. All rights reserved.

  2. Population genetic diversity of marble goby (Oxyeleotris marmoratus ...

    Indian Academy of Sciences (India)

    Cheng Zhao

    2017-12-08

    Dec 8, 2017 ... Indian Academy of Sciences. ONLINE ... east Asia, especially in Malaysia, Singapore, Thailand and. Vietnam (Inger and ... cial culture of marble goby has suffered from germplasm degradation ..... Southeast Asia. Through ...

  3. How cuckoldry can decrease the opportunity for sexual selection: Data and theory from a genetic parentage analysis of the sand goby, Pomatoschistus minutus

    Science.gov (United States)

    Jones, Adam G.; Walker, DeEtte; Kvarnemo, Charlotta; Lindström, Kai; Avise, John C.

    2001-01-01

    Alternative mating strategies are common in nature and are generally thought to increase the intensity of sexual selection. However, cuckoldry can theoretically decrease the opportunity for sexual selection, particularly in highly polygamous species. We address here the influence of sneaking (fertilization thievery) on the opportunity for sexual selection in the sand goby Pomatoschistus minutus, a marine fish species in which males build and defend nests. Our microsatellite-based analysis of the mating system in a natural sand goby population shows high rates of sneaking and multiple mating by males. Sneaker males had fertilized eggs in ≈50% of the assayed nests, and multiple sneakers sometimes fertilized eggs from a single female. Successful males had received eggs from 2 to 6 females per nest (mean = 3.4). We developed a simple mathematical model showing that sneaking in this polygynous sand goby population almost certainly decreases the opportunity for sexual selection, an outcome that contrasts with the usual effects of cuckoldry in socially monogamous animals. These results highlight a more complex and interesting relationship between cuckoldry rates and the intensity of sexual selection than previously assumed in much of the literature on animal mating systems. PMID:11481481

  4. Effects of sewage effluent and ethynyl oestradiol upon molecular markers of oestrogenic exposure, maturation and reproductive success in the sand goby (Pomatoschistus minutus, Pallas)

    International Nuclear Information System (INIS)

    Robinson, Craig D.; Brown, Elaine; Craft, John A.; Davies, Ian M.; Moffat, Colin F.; Pirie, David; Robertson, Fiona; Stagg, Ronald M.; Struthers, Susan

    2003-01-01

    Male fish in several UK estuaries are known to be exposed to oestrogenic contamination, and whilst a limited number of studies have shown that exposure to oestrogens can reduce the reproductive success of fish, the impact of environmentally relevant exposures is less clear. The aim of this study was, therefore, to investigate the effects of exposure to environmentally realistic concentrations of a sewage effluent and the synthetic oestrogen 17α-ethynyl oestradiol (EE 2 ) upon the reproductive success of a marine fish. Sand goby (Pomatoschistus minutus) were exposed for 7 months to EE 2 or a sewage effluent containing known xeno-oestrogens (alkylphenol polyethoxylates) and bred using within treatment crosses. Nominal exposure concentrations were 6 ng l -1 EE 2 , 0.3 or 0.03% v/v sewage effluent. At the end of the breeding trials, expression of hepatic zona radiata protein (Zrp) and vitellogenin (Vtg) mRNA were determined using two recently developed cDNA probes. Exposure to 6 ng l -1 EE 2 induced Zrp and Vtg mRNA expression in male and female sand goby, impaired male maturation and reproductive behaviour, reduced female fecundity and reduced egg fertility. As a consequence, fertile egg production of the EE 2 -exposed population was reduced by 90%. Exposure to sewage effluent (0.3% v/v) increased adult mortality and female Zrp and Vtg mRNA expression, but did not induce male vitellogenesis. Exposure to EE 2 and 0.3% v/v sewage effluent impaired development of the male urogenital papilla. Fish exposed to 0.03% v/v sewage effluent produced more fertile eggs than those exposed to 0.3% effluent, or those receiving no effluent. It is concluded that male vitellogenesis in an oestrogenically exposed population may be accompanied by reduced reproductive success, but that it may not be indicative of altered reproductive output in a population exposed to an industrial sewage effluent

  5. Bioaccumulation of sodium alkyl sulfate zinc chloride and their mixture in young goby proterorhinus marmoratus pall

    Energy Technology Data Exchange (ETDEWEB)

    Topcuoglu, S.; Birol, E. (Cekmece Nuclear Research and Training Center, Istanbul (Turkey))

    1982-12-01

    The bioaccumulation of labelled surfactant, 35S-labelled sodium lauryl sulfate and 65Zn-labelled zinc chloride, was investigated both as a mixture and alone by themselves in young goby. The concentration factor of 7.15 was calculated for the surfactant in the whole-body fish and there was no effect of zinc chloride on this bioaccumulation process. Biological half-life of the surfactant was around 35 hours. The effects of surfactants on the zinc accumulation were also followed under the same conditions. The results indicated that the sodium lauryl sulfate had no effect on the accumulation of zinc, however, the other surfactant, linear alkylbenzene sulfonate, caused a significant increase in the zinc accumulation in comparison with the control group, during the uptake period.

  6. Bioaccumulation of sodium alkyl sulfate zinc chloride and their mixture in young goby proterorhinus marmoratus pall

    International Nuclear Information System (INIS)

    Topcuoglu, S.; Birol, E.

    1982-01-01

    The bioaccumulation of labelled surfactant, 35S-labelled sodium lauryl sulfate and 65Zn-labelled zinc chloride, was investigated both as a mixture and alone by themselves in young goby. The concentration factor of 7.15 was calculated for the surfactant in the whole-body fish and there was no effect of zinc chloride on this bioaccumulation process. Biological half-life of the surfactant was around 35 hours. The effects of surfactants on the zinc accumulation were also followed under the same conditions. The results indicated that the sodium lauryl sulfate had no effect on the accumulation of zinc, however, the other surfactant, linear alkylbenzene sulfonate, caused a significant increase in the zinc accumulation in comparison with the control group, during the uptake period. (author)

  7. EFFECTS OF DIFFERENT TYPES OF FEED ON GROWTH, SURVIVAL AND DIGESTIVE ENZYME ACTIVITY OF EARLY JUVENILE-STAGE MARBLE GOBY, Oxyeleotris marmoratus

    Directory of Open Access Journals (Sweden)

    Muhammad Darwis

    2008-06-01

    Full Text Available The stable mass seed production technique of marble goby, Oxyeleotris marmoratus has not yet been established due to high mortality occurring on the early juvenile stage and/or after 40 days after hatching (d AH. In order to establish the mass seed production technique, O. marmoratus juveniles of 40 d AH were reared for 60 days to determine growth, survival and digestive enzyme activity at different types of feed (trash fish, artificial feed and Artemia sp. nauplii. Specific growth rate (5.32 and survival rate (91.3% in juveniles fed Artemia sp. nauplii showed significantly higher (P<0.05 than those of juveniles fed trash fish and artificial feed. At the end of the experiment, the mean specific trypsin, amylase and lipase activities of juveniles fed Artemia sp. nauplii were recorded as 0.04 mU mg protein-1m-1, 0.114 mg maltose mg protein-1h-1 and 9.58 m Units, respectively, and they were significantly higher than those of juveniles fed trash fish and artificial feed. In the present study it was shown that O. marmoratus early juveniles had more efficient digestibility and absorption the nutrient when fed with Artemia.

  8. Temperature rise and microplastics interact with the toxicity of the antibiotic cefalexin to juveniles of the common goby (Pomatoschistus microps): Post-exposure predatory behaviour, acetylcholinesterase activity and lipid peroxidation.

    Science.gov (United States)

    Fonte, Elsa; Ferreira, Pedro; Guilhermino, Lúcia

    2016-11-01

    The goal of this study was to investigate the toxicity of cefalexin to Pomatoschistus microps juveniles in relation to the presence of microplastics in the water and temperature rise. After acclimatization, groups of wild juveniles were exposed for 96h to artificial salt water (control), microplastics alone (0.184mg/l), cefalexin alone (1.3-10mg/l) and in mixture with microplastics (cefalexin: 1.3-10mg/l; microplastics: 0.184mg/l) at 20 and 25°C. Effect criteria were mortality, post-exposure predatory performance (PEPP), acetylcholinesterase activity (AChE) and lipid peroxidation levels (LPO). At 20°C, concentrations of cefalexin alone≥5mg/l significantly reduced PEPP (up to 56%; 96h-EC 50 =8.4mg/l), indicating toxicity of the antibiotic to juveniles after short-term exposure to water concentrations in the low ppm range. At 20°C, fish exposed to microplastics alone did not have significant differences in any of the parameters tested relative to the control group but tended to have an inhibition of the PEPP (23%) and AChE (21%); at 25°C, microplastics alone caused mortality (33%) and PEPP inhibition (28%). Thus, microplastics are toxic to P. microps juveniles. At 20°C, under simultaneous exposure to cefalexin and microplastics, the PEPP was significantly reduced (at cefalexin concentrations≥1.25mg/l). Moreover, at 25°C, the toxicity curves of cefalexin (PEPP based), alone and in mixture with microplastics, were significantly different (pmicroplastics in the water influenced the toxicity of cefalexin. The rise of water temperature (from 20°C to 25°C), increased the microplastics-induced mortality (from 8 to 33%), and the inhibitory effects of cefalexin on the PEPP (up to 70%). Significant differences (pmicroplastics and of cefalexin, alone and in mixture with microplastics, to P. microps juveniles. These findings raise concern on the long-term exposure of wild populations to complex mixtures of pollutants, likely decreasing their fitness, and highlight

  9. Socially induced tactic change in 2 types of sand goby sneaker males

    OpenAIRE

    Takeshi Takegaki; Ola Svensson; Charlotta Kvarnemo

    2012-01-01

    Male alternative reproductive tactics, like satellite or sneaking tactics, typically parasitize reproductively on a larger resource-holding tactic. In the sand goby, Pomatoschistus minutus, 2 types of sneaker males are known. Sneaker males with melanization, a typical male breeding coloration, have small testes and large sperm-duct glands, and sneaker males without melanization have large testes and small sperm-duct glands. We tested their potential to change into the nest-holding tactic expe...

  10. Population genetic diversity of marble goby (Oxyeleotris marmoratus ...

    Indian Academy of Sciences (India)

    Navya

    2017-03-31

    Mar 31, 2017 ... Our study will provide valuable information for facilitating the ... traditional method with constructing microsatellite-enriched library (Luo et al. .... important that the protection of wild stock and more wild resources should be ...

  11. Sexually selected nest-building--Pomatoschistus minutus males build smaller nest-openings in the presence of sneaker males.

    Science.gov (United States)

    Svensson, O; Kvarnemo, C

    2003-09-01

    Both natural selection and sexual selection may act on nest-building. We tested experimentally how different regimes of egg-predation and male-male competition influence nest-building before mating, using the marine fish sand goby, Pomatoschistus minutus. Males with sneaker males present built the smallest nest-openings, smaller than males held alone or with Pomatoschistus microps males (which may predate eggs and compete over nest-sites but not compete over fertilizations). Males with visual access to other nest-building males tended also to build smaller openings than males held alone or with P. microps. Males with egg-predators present built nests with openings not differing significantly from any other treatment. Our results indicate that the small nest-openings found in the sneaker male treatment are sexually selected through protection against sneaking or by female choice. Across treatments, time span before a male started to build his nest also explained variation in nest-opening width; males starting late built larger nest-openings.

  12. Parasitic spawning in sand gobies: an experimental assessment of nest-opening size, sneaker male cues, paternity, and filial cannibalism

    OpenAIRE

    Ola Svensson; Charlotta Kvarnemo

    2007-01-01

    Sneaking is common in nest-building fish with paternal care, but the role of nest-opening size in protecting against entry by sneaker males has never been tested before. Using the sand goby (Pomatoschistus minutus), a fish with exclusive paternal care, experimental manipulations of nest openings provided no support for the hypothesis that nest openings serve as physical or visual defense or that sneaker males prefer to parasitize nests with wide openings. Female mating preference was also not...

  13. Depletion rates of gastrointestinal content in common goby (Pomatoschistus microps (Kr.))

    DEFF Research Database (Denmark)

    Andersen, Niels Gerner

    1984-01-01

    Relatively complicated surgery is a necessity when implanting sensors internally in fish in order to measure physiological variables at specific locations. A surgical procedure from implanting transmitters with remote sensors into the body cavity of cod (Gadus morhua L.) is presented. The method ...

  14. Phylogeny of Gobioidei and the origin of European gobies

    Directory of Open Access Journals (Sweden)

    Ainhoa Agorreta

    2015-11-01

    Full Text Available The percomorph order Gobioidei comprises over 2200 species worldwide distributed that occupy most freshwater, brackish and marine environments, and show a spectacular variety in morphology, ecology, and behaviour. However, phylogenetic relationships among many gobioid groups still remain poorly understood. Such is the case of Gobiidae, a rapidly radiating lineage that encompass an unusually high diversity of species (nearly 2000, including the largely endemic European species whose origin and ancestry remain uncertain. The resolution and accuracy of previous molecular phylogenetic studies has been limited due to the use of only a few (generally mitochondrial molecular markers and/or the absence of representatives of several key lineages. Our study (built on Agorreta et al. 2013 is the first to include multiple nuclear and mitochondrial genes for nearly 300 terminal taxa representing the vast diversity of gobioid lineages. We have used this information to reconstruct a robust phylogeny of Gobioidei, and we are now investigating the historical biogeography and diversification times of European gobies with a time-calibrated molecular phylogeny. Robustness of the inferred phylogenetic trees is significantly higher than that of previous studies, hence providing the most compelling molecular phylogenetic hypotheses for Gobioidei thus far. The family Eleotrididae branches off the gobioid tree after the Rhyacichthyidae + Odontobutidae clade followed by the Butidae as the sister-group of the Gobiidae. Several monophyletic groups are identified within the two major Gobiidae subclades, the gobionelline-like and the gobiine-like gobiids. The European gobies cluster in three distinct lineages (Pomatoschistus-, Aphia-, and Gobius-lineages, each with different affinities with gobiids from the Indo-Pacific and perhaps the New World. Our ongoing more-detailed study on European gobies will reveal whether their origin is related to vicariant events linked to the

  15. Tubenose goby Proterorhinus marmoratus (Pallas, 1814) has joined three other Ponto-Caspian gobies in the Vistula River (Poland)

    Czech Academy of Sciences Publication Activity Database

    Grabowska, J.; Pietraszewski, D.; Ondračková, Markéta

    2008-01-01

    Roč. 3, č. 2 (2008), s. 261-265 ISSN 1818-5487 Institutional research plan: CEZ:AV0Z60930519 Keywords : gobiids * invasive species * invasion corridor Subject RIV: EH - Ecology, Behaviour http://www.aquaticinvasions.ru/2008/AI_2008_3_2_Grabowska_etal.pdf

  16. Investment in testes, sperm-duct glands and lipid reserves differs between male morphs but not between early and late breeding season in Pomatoschistus minutus.

    Science.gov (United States)

    Kvarnemo, C; Svensson, O; Manson, W

    2010-05-01

    This study of the sand goby Pomatoschistus minutus, a nest-holding fish with paternal care, focused on gonadal investment among males of different sizes collected early and late in the breeding season. All males caught at the nest had breeding colour, whereas trawl-caught fish consisted of males both with and without colour. The absence or presence of breeding colour was a good predictor of testes investment. Compared to males with breeding colour, males without colour were smaller in body size but had extraordinarily large testes. In absolute terms, testes mass of males without breeding colour was on average 3.4 times greater than those of males with breeding colour. Since small colourless males are known to reproduce as sneaker males, this heavy investment in testes probably reflects that they are forced to spawn under sperm competition. Contrary to testes size, sperm-duct glands were largest among males with breeding colour. These glands produce mucins used for making sperm-containing mucous trails that males place in the nest before and during spawning. Since both sneakers and nest-holders potentially could benefit from having large glands, this result is intriguing. Yet, high mucus production may be more important for nest-holders, because it also protects developing embryos from infections. There was no significant effect of season on body size, testes or sperm-duct glands size, but colourless males tended to be less common late in the season. Possibly this may indicate that individual small colourless males develop into their more colourful counterparts within the breeding season.

  17. Effects of local and large-scale climate patterns on estuarine resident fishes: The example of Pomatoschistus microps and Pomatoschistus minutus

    Science.gov (United States)

    Nyitrai, Daniel; Martinho, Filipe; Dolbeth, Marina; Rito, João; Pardal, Miguel A.

    2013-12-01

    Large-scale and local climate patterns are known to influence several aspects of the life cycle of marine fish. In this paper, we used a 9-year database (2003-2011) to analyse the populations of two estuarine resident fishes, Pomatoschistus microps and Pomatoschistus minutus, in order to determine their relationships with varying environmental stressors operating over local and large scales. This study was performed in the Mondego estuary, Portugal. Firstly, the variations in abundance, growth, population structure and secondary production were evaluated. These species appeared in high densities in the beginning of the study period, with subsequent occasional high annual density peaks, while their secondary production was lower in dry years. The relationships between yearly fish abundance and the environmental variables were evaluated separately for both species using Spearman correlation analysis, considering the yearly abundance peaks for the whole population, juveniles and adults. Among the local climate patterns, precipitation, river runoff, salinity and temperature were used in the analyses, and North Atlantic Oscillation (NAO) index and sea surface temperature (SST) were tested as large-scale factors. For P. microps, precipitation and NAO were the significant factors explaining abundance of the whole population, the adults and the juveniles as well. Regarding P. minutus, for the whole population, juveniles and adults river runoff was the significant predictor. The results for both species suggest a differential influence of climate patterns on the various life cycle stages, confirming also the importance of estuarine resident fishes as indicators of changes in local and large-scale climate patterns, related to global climate change.

  18. An endocrine disrupting chemical changes courtship and parental care in the sand goby

    International Nuclear Information System (INIS)

    Saaristo, Minna; Craft, John A.; Lehtonen, Kari K.; Lindstroem, Kai

    2010-01-01

    Endocrine disrupting chemicals (EDCs) are a diverse group of compounds that can mimic, block or modulate the synthesis of natural hormones. They are known to cause impairment of reproduction of aquatic organisms at very low concentrations. The aim of this study was to examine how exposure from 10 to 31 days to 17α-ethinyl estradiol (EE2, 41 ng L -1 ) affects the courtship and parental care behaviour of male sand gobies (Pomatoschistus minutus). The sand goby exhibits a polygynous mating system, where males compete for females and provide paternal care. First, male courtship performance towards a stimulus female was recorded with video camera. Secondly, after the male had received eggs his parental care behaviour was video recorded. In addition to behavioural endpoints, we measured the expression of hepatic vitellogenin (Vtg) and zona radiata protein (Zrp) mRNA, as well as common somatic indices. Our study shows that exposure to EE2 affected male fanning behaviour during both courtship and parental care. Interestingly, small exposed males increased their courtship fanning to similar levels as larger control males. However, during parental care egg fanning was not related to male size, and all exposed males fanned more than control males. The EE2-exposure induced Vtg and Zrp mRNA expression in males and decreased hepatosomatic index (HSI), and increased gonadosomatic index (GSI). Females prefer males that fan more, which will favour the small EDC exposed males. This may lead to mating that favours males that are not strong enough to tend the eggs until they hatch, thus decreasing the reproductive success of individuals.

  19. An endocrine disrupting chemical changes courtship and parental care in the sand goby

    Energy Technology Data Exchange (ETDEWEB)

    Saaristo, Minna, E-mail: Minna.Saaristo@helsinki.fi [Department of Bio- and Environmental Sciences, University of Helsinki, P.O. Box 65, FI-00014 Helsinki (Finland); Craft, John A. [Biological and Biomedical Sciences, Glasgow Caledonian University, Cowcaddens Road, Glasgow G4 0BA, Scotland (United Kingdom); Lehtonen, Kari K. [Finnish Environment Institute, Marine Research Centre, P.O. Box 140, FI-00251 Helsinki (Finland); Lindstroem, Kai [Environmental and Marine Biology, Abo Akademi University, FI-20520 Turku (Finland)

    2010-05-10

    Endocrine disrupting chemicals (EDCs) are a diverse group of compounds that can mimic, block or modulate the synthesis of natural hormones. They are known to cause impairment of reproduction of aquatic organisms at very low concentrations. The aim of this study was to examine how exposure from 10 to 31 days to 17{alpha}-ethinyl estradiol (EE2, 41 ng L{sup -1}) affects the courtship and parental care behaviour of male sand gobies (Pomatoschistus minutus). The sand goby exhibits a polygynous mating system, where males compete for females and provide paternal care. First, male courtship performance towards a stimulus female was recorded with video camera. Secondly, after the male had received eggs his parental care behaviour was video recorded. In addition to behavioural endpoints, we measured the expression of hepatic vitellogenin (Vtg) and zona radiata protein (Zrp) mRNA, as well as common somatic indices. Our study shows that exposure to EE2 affected male fanning behaviour during both courtship and parental care. Interestingly, small exposed males increased their courtship fanning to similar levels as larger control males. However, during parental care egg fanning was not related to male size, and all exposed males fanned more than control males. The EE2-exposure induced Vtg and Zrp mRNA expression in males and decreased hepatosomatic index (HSI), and increased gonadosomatic index (GSI). Females prefer males that fan more, which will favour the small EDC exposed males. This may lead to mating that favours males that are not strong enough to tend the eggs until they hatch, thus decreasing the reproductive success of individuals.

  20. Painted Goby Larvae under High-CO2 Fail to Recognize Reef Sounds.

    Directory of Open Access Journals (Sweden)

    Joana M Castro

    Full Text Available Atmospheric CO2 levels have been increasing at an unprecedented rate due to anthropogenic activity. Consequently, ocean pCO2 is increasing and pH decreasing, affecting marine life, including fish. For many coastal marine fishes, selection of the adult habitat occurs at the end of the pelagic larval phase. Fish larvae use a range of sensory cues, including sound, for locating settlement habitat. This study tested the effect of elevated CO2 on the ability of settlement-stage temperate fish to use auditory cues from adult coastal reef habitats. Wild late larval stages of painted goby (Pomatoschistus pictus were exposed to control pCO2 (532 μatm, pH 8.06 and high pCO2 (1503 μatm, pH 7.66 conditions, likely to occur in nearshore regions subjected to upwelling events by the end of the century, and tested in an auditory choice chamber for their preference or avoidance to nighttime reef recordings. Fish reared in control pCO2 conditions discriminated reef soundscapes and were attracted by reef recordings. This behaviour changed in fish reared in the high CO2 conditions, with settlement-stage larvae strongly avoiding reef recordings. This study provides evidence that ocean acidification might affect the auditory responses of larval stages of temperate reef fish species, with potentially significant impacts on their survival.

  1. Fries' goby, a European oddity

    Directory of Open Access Journals (Sweden)

    Peter J Miller

    2015-12-01

    Full Text Available Fries' Goby, Lesueurigobius friesii (Malm, 1874 is common on softer grounds of the more offshore eastern Atlantic continental shelf from Norway to Mauritania, and in the Mediterranean to the Sea of Marmora. The several species of the genus are unique among Lusitanian/Boreal gobiine gobies in coloration and caudal morphology as well as in the 'longitudinal' pattern of infraorbital free neuromast-organs and the lack of head lateral-line canals. A new classification of Old World longitudinal gobiines, based on these free neuromast patterns of both infraorbital and hyomandibular innervation, places Lesueurigobius as the Atlantic sister group to the other longitudinal gobiines, which are all Indo/West Pacific in distribution. The proposed cladogram, the first for the group, is based on synapomorphies in features of rostral mandibular line neuromast series f, the rows of the cheek, and vertebral number. Species of Lesueurigobius show an apparently apomorphic reduction in infraorbital row cp that is shared with three Indo-West Pacific genera (Silhouettea, Heteroplopomus and Platygobiopsis but, in Lesueurigobius , this is now believed to be plesiomorphic. Morphological character states were used to construct a cladogram which was discussed in relation to molecular findings that support Lesueurigobius as an outgroup to the Indo/West Pacific genera. The importance of the latter as tools for testing morphological phylogenies, rather than as conflicting classification, is strongly emphasised.

  2. Use of electrical barriers to deter movement of round goby

    Science.gov (United States)

    Savino, Jacqueline F.; Jude, David J.; Kostich, Melissa J.; Coutant, Charles C.

    2001-01-01

    An electrical barrier was chosen as a possible means to deter movement of round goby Neogobius melanostomus. Feasibility studies in a 2.1-m donut-shaped tank determined the electrical parameters necessary to inhibit round goby from crossing the 1-m stretch of the benthic, electrical barrier. Increasing electrical pulse duration and voltage increased effectiveness of the barrier in deterring round goby movement through the barrier. Differences in activity of round goby during daytime and nocturnal tests did not change the effectiveness of the barrier. In field verification studies, an electrical barrier was placed between two blocking nets in the Shiawassee River, Michigan. The barrier consisted of a 6-m wide canvas on which were laid four cables carrying the electrical current. Seven experiments were conducted, wherein 25 latex paint-marked round goby were introduced upstream of the electrical barrier and recovered 24 h later upstream, on, and downstream of the barrier. During control studies, round goby moved across the barrier within 20 min from release upstream. With the barrier on and using the prescribed electrical settings shown to inhibit passage in the laboratory, the only marked round goby found below the barrier were dead. At reduced pulse durations, a few round goby (mean one/test) were found alive, but debilitated, below the barrier. The electrical barrier could be incorporated as part of a program in reducing movement of adult round goby through artificial connections between watersheds.

  3. Rockpool gobies change colour for camouflage.

    Directory of Open Access Journals (Sweden)

    Martin Stevens

    Full Text Available Camouflage is found in a wide range of species living in numerous habitat types, offering protection from visually guided predators. This includes many species from the intertidal zone, which must cope with background types diverse in appearance and with multiple predator groups foraging at high and low tide. Many animals are capable of either relatively slow (hours, days, weeks or rapid (seconds and minutes colour change in order to better resemble the background against which they are found, but most work has been restricted to a few species or taxa. It is often suggested that many small intertidal fish are capable of colour change for camouflage, yet little experimental work has addressed this. Here, we test rock gobies (Gobius paganellus for colour change abilities, and whether they can tune their appearance to match the background. In two experiments, we place gobies on backgrounds of different brightness (black or white, and of different colours (red and blue and use digital image analysis and modelling of predator (avian vision to quantify colour and luminance (perceived lightness changes and camouflage. We find that gobies are capable of rapid colour change (occurring within one minute, and that they can change their luminance on lighter or darker backgrounds. When presented on backgrounds of different colours, gobies also change their colour (hue and saturation while keeping luminance the same. These changes lead to predicted improvements in camouflage match to the background. Our study shows that small rockpool fish are capable of rapid visual change for concealment, and that this may be an important mechanism in many species to avoid predation, especially in complex heterogeneous environments.

  4. Rockpool gobies change colour for camouflage.

    Science.gov (United States)

    Stevens, Martin; Lown, Alice E; Denton, Alexander M

    2014-01-01

    Camouflage is found in a wide range of species living in numerous habitat types, offering protection from visually guided predators. This includes many species from the intertidal zone, which must cope with background types diverse in appearance and with multiple predator groups foraging at high and low tide. Many animals are capable of either relatively slow (hours, days, weeks) or rapid (seconds and minutes) colour change in order to better resemble the background against which they are found, but most work has been restricted to a few species or taxa. It is often suggested that many small intertidal fish are capable of colour change for camouflage, yet little experimental work has addressed this. Here, we test rock gobies (Gobius paganellus) for colour change abilities, and whether they can tune their appearance to match the background. In two experiments, we place gobies on backgrounds of different brightness (black or white), and of different colours (red and blue) and use digital image analysis and modelling of predator (avian) vision to quantify colour and luminance (perceived lightness) changes and camouflage. We find that gobies are capable of rapid colour change (occurring within one minute), and that they can change their luminance on lighter or darker backgrounds. When presented on backgrounds of different colours, gobies also change their colour (hue and saturation) while keeping luminance the same. These changes lead to predicted improvements in camouflage match to the background. Our study shows that small rockpool fish are capable of rapid visual change for concealment, and that this may be an important mechanism in many species to avoid predation, especially in complex heterogeneous environments.

  5. Evidence for predatory control of the invasive round goby

    Science.gov (United States)

    Madenjian, C.P.; Stapanian, M.A.; Witzel, L.D.; Einhouse, D.W.; Pothoven, S.A.; Whitford, H.L.

    2011-01-01

    We coupled bioenergetics modeling with bottom trawl survey results to evaluate the capacity of piscivorous fish in eastern Lake Erie to exert predatory control of the invading population of round goby Neogobius melanostomus. In the offshore (>20 m deep) waters of eastern Lake Erie, burbot Lota lota is a native top predator, feeding on a suite of prey fishes. The round goby invaded eastern Lake Erie during the late 1990s, and round goby population size increased dramatically during 1999–2004. According to annual bottom trawl survey results, round goby abundance in offshore waters peaked in 2004, but then declined during 2004–2008. Coincidentally, round goby became an important component of burbot diet beginning in 2003. Using bottom trawling and gill netting, we estimated adult burbot abundance and age structure in eastern Lake Erie during 2007. Diet composition and energy density of eastern Lake Erie burbot were also determined during 2007. This information, along with estimates of burbot growth, burbot mortality, burbot water temperature regime, and energy densities of prey fish from the literature, were incorporated into a bioenergetics model application to estimate annual consumption of round goby by the adult burbot population. Results indicated that the adult burbot population in eastern Lake Erie annually consumed 1,361 metric tons of round goby. Based on the results of bottom trawling, we estimated the biomass of yearling and older round goby in offshore waters eastern Lake Erie during 2007–2008 to be 2,232 metric tons. Thus, the adult burbot population was feeding on round goby at an annual rate equal to 61% of the estimated round goby standing stock. We concluded that the burbot population had high potential to exert predatory control on round goby in offshore waters of eastern Lake Erie.

  6. Downstream drift of round goby (Neogobius melanostomus) and tubenose goby (Proterorhinus semilunaris) in their non-native area

    Czech Academy of Sciences Publication Activity Database

    Janáč, Michal; Šlapanský, Luděk; Valová, Zdenka; Jurajda, Pavel

    2013-01-01

    Roč. 22, č. 3 (2013), s. 430-438 ISSN 0906-6691 R&D Projects: GA ČR(CZ) GAP505/11/1768 Institutional support: RVO:68081766 Keywords : invasive species * dispersal * drift * round goby * tubenose goby * Gobiidae Subject RIV: EH - Ecology, Behaviour Impact factor: 1.590, year: 2013

  7. Tributyltin exposure causes brain damage in Sebastiscus marmoratus.

    Science.gov (United States)

    Zhang, Jiliang; Zuo, Zhenghong; Chen, Rong; Chen, Yixin; Wang, Chonggang

    2008-09-01

    Tributyltin (TBT) is a ubiquitous marine environmental contaminant characterized primarily by its reproductive toxicity. However, the neurotoxic effect of TBT has not been extensively described, especially in fishes which have a high number of species in the marine environment. This study was conducted to investigate the neurotoxic effects of TBT at environmental levels (1, 10, and 100ngl(-1)) on female Sebastiscus marmoratus. The results showed that TBT exposure induced apoptosis in brain cells of three regions including the pallial areas of the telencephalon, the granular layer of the optic tectum, and the cerebellum. In addition, the increase of reactive oxygen species and nitric oxide levels, and the decrease of Na+/K+-ATPase activity were found in the brain. The results strongly indicated neurotoxicity of TBT to fishes. According to the regions in which apoptosis was found in the brain, TBT exposure might influence the schooling, sensory and motorial functions of fishes.

  8. Postflood persistence and recolonization of endangered tidewater goby populations

    Science.gov (United States)

    Lafferty, Kevin D.; Swift, Camm C.; Ambrose, Richard F.

    1999-01-01

    Before-and-after surveys at several southern California sites indicated that populations of endangered tidewater goby Eucyclogobius newberryi persisted through heavy flooding in 1995. This was contrary to our expectations that flooding might have led to extirpation in some smaller wetlands. There was also no significant change in tidewater goby density before and after the flooding. Several apparent recolonization events coincided with the flood, suggesting that flooding may be important for the long-term persistence of the species.

  9. Pathogenic fungus Batrachochytrium dendrobatidis in marbled water frog Telmatobius marmoratus: first record from Lake Titicaca, Bolivia.

    Science.gov (United States)

    Cossel, John; Lindquist, Erik; Craig, Heather; Luthman, Kyle

    2014-11-13

    The pathogenic fungus Batrachochytrium dendrobatidis (Bd) has been associated with amphibian declines worldwide but has not been well-studied among Critically Endangered amphibian species in Bolivia. We sampled free-living marbled water frogs Telmatobius marmoratus (Anura: Leptodactylidae) from Isla del Sol, Bolivia, for Bd using skin swabs and quantitative polymerase chain reactions. We detected Bd on 44% of T. marmoratus sampled. This is the first record of Bd in amphibians from waters associated with Lake Titicaca, Bolivia. These results further confirm the presence of Bd in Bolivia and substantiate the potential threat of this pathogen to the Critically Endangered, sympatric Titicaca water frog T. culeus and other Andean amphibians.

  10. Response of round gobies, Neogobius melanostomus, to conspecific sounds

    Science.gov (United States)

    Isabella-Valenzi, Lisa

    A useful model group to examine reproductive plasticity in acoustic responsiveness is the family Gobiidae. Male round gobies Neogobius melanostomus emit calls and females respond to these calls with high specificity. The current study investigates differential attraction between reproductive morphologies of the goby to conspecific calls and explores the use of calls to develop a bioacoustic trap. Behavioural responsiveness to conspecific calls was tested using playback experiments in the lab and field. Females showed a strong attraction to the grunt call in both the lab and field, while nonreproductive and sneaker males preferred the drum call in the lab, but favoured the grunt call in the field. By determining the relationship between reproductive state and auditory responsiveness to conspecific calls, I am further elucidating the function of acoustic communication in the round goby and may be essential when creating control strategies to prevent the spread of the invasive species.

  11. Phenotypic differences between the sexes in the sexually plastic mangrove rivulus fish (Kryptolebias marmoratus)

    DEFF Research Database (Denmark)

    Garcia, Mark J.; Ferro, Jack M.; Mattox, Tyler

    2016-01-01

    the sexes in a sexchanging vertebrate, the mangrove rivulus fish (Kryptolebias marmoratus), to elucidate potential factors that might drive the ‘decision’ to switch sex. Rivulus populations consist of self-fertilizing hermaphrodites and males. Hermaphrodites transition into males under certain environmental...

  12. First record of Rivulus marmoratus Poey, 1880 From the South American continent (Pisces: Cyprinodontidae)

    NARCIS (Netherlands)

    Taphorn, D.C.

    1980-01-01

    Rivulus marmoratus Poey, 1880 has previously been found only in south Florida, Cuba, the Bahamas, Barbuda, St. Martin and several islands off the Venezuelan coast (Curaçao, Bonaire and Gran Roque) (Hoedeman, 1958; Böhlke & Chaplin, 1968). In September of 1978, one of my students, Mr. Edgard W.

  13. The Use of "Kryptolebias marmoratus" Eggs as an Educational Tool for Embryology Education

    Science.gov (United States)

    Genade, Tyrone

    2016-01-01

    Plastic embryological models lack the excitement of seeing real, live embryos. Chick embryos are often used to demonstrate embryological development and blood circulation to students but this necessitates the death of the organism. "Kryptolebias marmoratus" embryos are large and can be viewed by means of a light microscope without need…

  14. Neuroepithelial cells and the hypoxia emersion response in the amphibious fish Kryptolebias marmoratus.

    Science.gov (United States)

    Regan, Kelly S; Jonz, Michael G; Wright, Patricia A

    2011-08-01

    Teleost fish have oxygen-sensitive neuroepithelial cells (NECs) in the gills that appear to mediate physiological responses to hypoxia, but little is known about oxygen sensing in amphibious fish. The mangrove rivulus, Kryptolebias marmoratus, is an amphibious fish that respires via the gills and/or the skin. First, we hypothesized that both the skin and gills are sites of oxygen sensing in K. marmoratus. Serotonin-positive NECs were abundant in both gills and skin, as determined by immunohistochemical labelling and fluorescence microscopy. NECs retained synaptic vesicles and were found near nerve fibres labelled with the neuronal marker zn-12. Skin NECs were 42% larger than those of the gill, as estimated by measurement of projection area, and 45% greater in number. Moreover, for both skin and gill NECs, NEC area increased significantly (30-60%) following 7 days of exposure to hypoxia (1.5 mg l(-1) dissolved oxygen). Another population of cells containing vesicular acetylcholine transporter (VAChT) proteins were also observed in the skin and gills. The second hypothesis we tested was that K. marmoratus emerse in order to breathe air cutaneously when challenged with severe aquatic hypoxia, and this response will be modulated by neurochemicals associated chemoreceptor activity. Acute exposure to hypoxia induced fish to emerse at 0.2 mg l(-1). When K. marmoratus were pre-exposed to serotonin or acetylcholine, they emersed at a significantly higher concentration of oxygen than untreated fish. Pre-exposure to receptor antagonists (ketanserin and hexamethonium) predictably resulted in fish emersing at a lower concentration of oxygen. Taken together, these results suggest that oxygen sensing occurs at the branchial and/or cutaneous surfaces in K. marmoratus and that serotonin and acetylcholine mediate, in part, the emersion response.

  15. The Review of Ecological and Genetic Research of Ponto-Caspian Gobies (Pisces, Gobiidae in Europe

    Directory of Open Access Journals (Sweden)

    Jakšić Goran

    2016-09-01

    Full Text Available Invasive Ponto-Caspian gobies (monkey goby Neogobius fluviatilis, round goby Neogobius melanostomus and bighead goby Ponticola kessleri have recently caused dramatic changes in fish assemblage structure throughout European river systems. This review provides summary of recent research on their dietary habits, age and growth, phylogenetic lineages and gene diversity. The principal food of all three species is invertebrates, and more rarely fish, which depends on the type of habitat, part of the year, as well as the morphological characteristics of species. According to the von Bertalanffy growth model, size at age is specific for the region, but due to its disadvantages it is necessary to test other growth models. Phylogenetic analysis of monkey goby and round goby indicates separation between the Black Sea and the Caspian Sea haplotypes. The greatest genetic diversity is found among populations of the Black Sea, and the lowest among European invaders. The lack of molecular research on bighead goby requires further studies.

  16. Study of food habits of Goby, Porogobius schlegelii (Gunther, 1861 ...

    African Journals Online (AJOL)

    The study examines the food habits of goby, Porogobius schelgelii from the artisanal fisheries of the Bonny River in the Niger Delta. The results show that detritus, diatoms and blue-green algae are the primary food items followed by sand granules, macrophytes and nematodes as secondary food items. Protozoa. Fish eggs ...

  17. Occurrence and food habits of the round goby in the profundal zone of southwestern Lake Ontario

    Science.gov (United States)

    Walsh, M.G.; Dittman, D.E.; O'Gorman, R.

    2007-01-01

    Little is known about the ecology of round goby (Neogobius melanostomus), an invasive benthic fish, in the profundal zone of the Great Lakes. In April 2002–2005 we caught increasing numbers of round gobies with a bottom trawl in the 45–150 m depth range of southwestern Lake Ontario. In 2005, we examined gut contents of 30 round gobies from each of three depths, 55, 95, and 130 m, and qualitatively compared gut contents with density of benthic invertebrates determined by Ponar grabs. Round goby guts contained mostly Dreissena spp. and opposum shrimp, Mysis relicta (Mysis); the frequency of occurrence of dreissenids in guts decreased with depth, whereas the frequency of occurrence of Mysis in guts increased with depth. Abundance of these invertebrates in the environment followed the same pattern, although dreissenids of optimum edible size (3–12 mm) were still abundant (1,373/m2) at 130 m, where round gobies primarily consumed Mysis, suggesting that round gobies may switch from dreissenids to more profitable prey when it is available. Other food items were ostracods and fish, with ostracods generally eaten by smaller round gobies and fish eaten by larger round gobies. Occurrence and increasing abundance of round gobies in the profundal zone and predation on Mysis by round goby could have far-reaching consequences for the Lake Ontario fish community.

  18. Study of the microwave emissivity characteristics over Gobi Desert

    International Nuclear Information System (INIS)

    Yubao, Qiu; Lijuan, Shi; Wenbo, Wu

    2014-01-01

    The microwave emissivity represents the capacity of the thermal radiation of the surface, and it is the significant parameter for understanding the geophysical processes such as surface energy budget and surface radiation. Different land covers have different emissivity properties, and the Gobi Desert in Central Asia seriously impact the sandstorms occur and develop in China, because of its special geographical environment and surface soil characteristics. In this study half-month averaged microwave emissivity from March 2003 to February 2004 over the Gobi Desert has been estimated. Emissivities in this area at different frequencies, polarization and their seasonal variations are discussed respectively. The results showed that emissivity polarization difference decrease as the frequency increases, and the polarization difference is large (0.03–0.127). The H polarization emissivity increases with increasing frequency, but the V-polarized microwave emissivity is reduced with increasing frequency because of the body scattering. In winter, emissivity decreases sharply in snow covered area, especially for higher frequencies (such as 89GHz). In addition, we compared emissivity with MODIS NDVI data at the same time in the Gobi Desert, and the results indicate that NDVI derived the good negative correlation with microwave emissivity polarization difference at 37GHz

  19. Marine, freshwater and aerially acclimated mangrove rivulus (Kryptolebias marmoratus) use different strategies for cutaneous ammonia excretion

    Science.gov (United States)

    Cooper, Christopher A.; Wilson, Jonathan M.

    2013-01-01

    Rhesus (Rh) glycoproteins are ammonia gas (NH3) channels known to be involved in ammonia transport in animals. Because of the different osmoregulatory and ionoregulatory challenges faced by teleost fishes in marine and freshwater (FW) environments, we hypothesized that ammonia excretion strategies would differ between environments. Also, we hypothesized that cutaneous NH3 volatilization in air-acclimated fish is facilitated by base secretion. To test these hypotheses, we used the skin of the euryhaline amphibious mangrove rivulus (Kryptolebias marmoratus). The skin excretes ammonia and expresses Rh glycoproteins. Serosal-to-mucosal cutaneous ammonia flux was saturable (0–16 mmol/l ammonia, Km of 6.42 mmol/l). In FW, ammonia excretion increased in response to low mucosal pH but decreased with pharmacological inhibition of Na+/H+ exchangers (NHE) and H+ ATPase. Conversely, in brackish water (BW), lowering the mucosal pH significantly decreased ammonia excretion. Inhibitors of NHE also decreased ammonia excretion in BW fish. Immunofluorescence microscopy demonstrated that both the Rh isoform, Rhcg1, and NHE3 proteins colocalized in Na+/K+ ATPase expressing mitochondrion-rich cells in the gills, kidney, and skin. We propose that the mechanisms of cutaneous ammonia excretion in FW K. marmoratus are consistent with the model for branchial ammonia excretion in FW teleost fish. NH4+ excretion appeared to play a stronger role in BW. NH4+ excretion in BW may be facilitated by apical NHE and/or diffuse through paracellular pathways. In aerially acclimated fish, inhibition of NHE and H+ ATPase, but not the Cl−/HCO3− exchanger, significantly affected cutaneous surface pH, suggesting that direct base excretion is not critical for NH3 volatilization. Overall, K. marmoratus use different strategies for excreting ammonia in three different environments, FW, BW, and air, and Rh glycoproteins and NHE are integral to all. PMID:23389109

  20. Copper alters hypoxia sensitivity and the behavioural emersion response in the amphibious fish Kryptolebias marmoratus.

    Science.gov (United States)

    Blewett, Tamzin A; Simon, Robyn A; Turko, Andy J; Wright, Patricia A

    2017-08-01

    Elevated levels of metals have been reported in mangrove ecosystems worldwide. Mangrove fishes also routinely experience severe environmental stressors, such as hypoxia. In the amphibious fish Kryptolebias marmoratus (mangrove rivulus), a key behavioural response to avoid aquatic stress is to leave water (emersion). We hypothesized that copper (Cu) exposure would increase the sensitivity of this behavioural hypoxia avoidance response due to histopathological effects of Cu on gill structure and function. K. marmoratus were exposed to either control (no added Cu) or Cu (300μg/L) for 96h. Following this period, fish were exposed to an acute hypoxic challenge (decline in dissolved oxygen to ∼0% over 15min), and the emersion response was recorded. Gills were examined for histological changes. Fish exposed to Cu emersed at a higher dissolved oxygen level (7.5±0.6%), relative to the control treatment group (5.8±0.4%). Histological analysis showed that the gill surface area increased and the interlamellar cell mass (ILCM) was reduced following Cu exposure, contrary to our prediction. Overall, these data indicate that Cu induces hypoxia-like changes to gill morphology and increases the sensitivity of the hypoxia emersion response. Copyright © 2017 Elsevier B.V. All rights reserved.

  1. Environmental physiology of the mangrove rivulus, Kryptolebias marmoratus, a cutaneously breathing fish that survives for weeks out of water.

    Science.gov (United States)

    Wright, Patricia A

    2012-12-01

    The mangrove rivulus (Kryptolebias marmoratus) is an excellent model species for understanding the physiological mechanisms that fish use in coping with extreme environmental conditions, particularly cutaneous exchange during prolonged exposure to air. Their ability to self-fertilize and produce highly homozygous lineages provides the potential for examining environmental influences on structures and related functions without the complications of genetic variation. Over the past 10 years or so, we have gained a broader understanding of the mechanisms K. marmoratus use to maintain homeostasis when out of water for days to weeks. Gaseous exchange occurs across the skin, as dramatic remodeling of the gill reduces its effective surface area for exchange. Ionoregulation and osmoregulation are maintained in air by exchanging Na(+), Cl(-), and H(2)O across skin that contains a rich population of ionocytes. Ammonia excretion occurs in part by cutaneous NH(3) volatilization facilitated by ammonia transporters on the surface of the epidermis. Finally, new evidence indicates that cutaneous angiogenesis occurs when K. marmoratus are emersed for a week, suggesting a higher rate of blood flow to surface vessels. Taken together, these and other findings demonstrate that the skin of K. marmoratus takes on all the major functions attributed to fish gills, allowing them to move between aquatic and terrestrial environments with ease. Future studies should focus on variation in response to environmental changes between homozygous lineages to identify the genetic underpinnings of physiological responses.

  2. Cloning and characterization of 29 tetranucleotide and two dinucleotide polymorphic microsatellite loci from the endangered marbled murrelet (Brachyramphus marmoratus)

    NARCIS (Netherlands)

    Rew, MB; Peery, MZ; Beissinger, Steven R.; Berube, M; Lozier, JD; Rubidge, EM; Palsboll, PJ

    We developed 31 novel, polymorphic microsatellite loci in the marbled murrelet (Brachyramphus marmoratus), a critically endangered seabird. Variability was tested on 15 individuals from the Santa Cruz, California population, with each locus characterized by two to 12 alleles. Observed levels of

  3. Environmental Physiology of the Mangrove Rivulus, Kryptolebias marmoratus, A Cutaneously Breathing Fish That Survives for Weeks Out of Water

    Science.gov (United States)

    Wright, Patricia A.

    2012-01-01

    The mangrove rivulus (Kryptolebias marmoratus) is an excellent model species for understanding the physiological mechanisms that fish use in coping with extreme environmental conditions, particularly cutaneous exchange during prolonged exposure to air. Their ability to self-fertilize and produce highly homozygous lineages provides the potential for examining environmental influences on structures and related functions without the complications of genetic variation. Over the past 10 years or so, we have gained a broader understanding of the mechanisms K. marmoratus use to maintain homeostasis when out of water for days to weeks. Gaseous exchange occurs across the skin, as dramatic remodeling of the gill reduces its effective surface area for exchange. Ionoregulation and osmoregulation are maintained in air by exchanging Na+, Cl−, and H2O across skin that contains a rich population of ionocytes. Ammonia excretion occurs in part by cutaneous NH3 volatilization facilitated by ammonia transporters on the surface of the epidermis. Finally, new evidence indicates that cutaneous angiogenesis occurs when K. marmoratus are emersed for a week, suggesting a higher rate of blood flow to surface vessels. Taken together, these and other findings demonstrate that the skin of K. marmoratus takes on all the major functions attributed to fish gills, allowing them to move between aquatic and terrestrial environments with ease. Future studies should focus on variation in response to environmental changes between homozygous lineages to identify the genetic underpinnings of physiological responses. PMID:22693260

  4. Reproduction of two-spotted goby, Gobiusculus flavescens, in captivity

    Directory of Open Access Journals (Sweden)

    Vera Teles

    2014-06-01

    Full Text Available The two-spotted goby, Gobiusculus flavescens, is a common fish species along rocky shores in northern European waters. It is a small (40-60 mm, semipelagic marine fish, forming loose shoals in association with microalgae vegetation and mussel beds growing on the rock surface. It is a short-lived species, with a life span of 1-2 years. Both sexes display courtship behaviour and have sexual ornamentation during the breeding season. Male ornaments consist of large dorsal fins with iridescent blue lines, and iridescent blue spots along the sides of the body. Females develop a conspicuous, bright orange belly at sexual maturity. Due to these characteristics this species could have a great interest for ornamental aquariums. In previous work the maintenance of G. flavescens at high temperatures (until 23°C was successful. The aim of this study was to test the reproduction in captivity of G. flavescens. Six replicates were used (18L aquariums at the temperature of 18°C. In each replicate, two males and four females were introduced to an aquarium, where the males chose between two nests and courted the females. During the 112 days of the experiment the females spawned five times but only three spawns had success. The eggs take approximately 8 days to become mature. On the three spawns have hatched 300, 361 and 510 larvae at a time. The larvae were kept in a separate container and fed with alive rotifers and survived a maximum of 21 days. The reproduction of the two-spotted goby in captivity is possible at 18°C, but it is necessary to improve the conditions to rearing the larvae.

  5. Plasticity of skin water permeability and skin thickness in the amphibious mangrove rivulus Kryptolebias marmoratus.

    Science.gov (United States)

    Heffell, Quentin; Turko, Andy J; Wright, Patricia A

    2018-03-01

    The skin of amphibious fishes is a multipurpose organ, important for gas and ion exchange and nitrogen excretion when fish are out of water (emersed). We tested the hypothesis that skin permeability is altered to maintain water balance through changes in water permeability and skin thickness during salinity acclimation and/or when fish emerse, using the euryhaline, amphibious fish Kryptolebias marmoratus as a model. We first recorded the behaviour of fish out of water to determine which part of the cutaneous surface was in contact with the substrate. Fish spent about 70% of their time on their ventral surface when out of water. Osmotic permeability of the skin was assessed in fish acclimated to 0.3 or 45‰ using 3 H 2 O fluxes in an in vitro micro-Ussing chamber setup. In freshwater-acclimated fish, 3 H 2 O influx across the skin was significantly higher compared to hypersaline-acclimated fish, with no significant changes in efflux. Prolonged emersion (7 days) resulted in an increase in skin 3 H 2 O influx, but not efflux in fish acclimated to a moist 45‰ substrate. In a separate experiment, dorsal epidermal skin thickness increased while the ventral dermis thickness decreased in fish emersed for over a week. However, there was no link between regional skin thickness and water flux in our experiments. Taken together, these findings suggest that K. marmoratus alter skin permeability to maximize water uptake while emersed in hypersaline conditions, adjustments that probably help them survive months of emersion during the dry season when drinking to replace water loss is not possible.

  6. Diet shift of double-crested cormorants in eastern Lake Ontario associated with the expansion of the invasive round goby

    Science.gov (United States)

    Johnson, James H.; Ross, Robert M.; McCullough, Russell D.; Mathers, Alastair

    2010-01-01

    The proliferation of the invasive round goby (Apollonia melanostoma) in the Great Lakes has caused shifts in the trophic ecology in some areas. We examined the diet of double-crested cormorants (Phalacrocorax auritas) prior to, and immediately after, round goby population expansion at two colonies, Pigeon and Snake Islands, in eastern Lake Ontario from 1999 to 2007. Cormorant diet was determined from the examination of 10,167 pellets collected over the nine-year period. By the second year round gobies were found in the diet (2002 at Snake Island and 2003 at Pigeon Island) they were the main species consumed by cormorants at each colony. The dominance of round goby in cormorant diets had a significant effect on both daily fish consumption and seasonal trends in fish consumption compared to the pre-goby years. Seasonal differences that were observed during the pre-goby years were lost once gobies became the main diet component of cormorants. The rapid switch to a benthic prey such as round goby, from a largely limnetic fish diet demonstrates the adaptive foraging ability of cormorants. Round goby may act as a buffer for yellow perch and smallmouth bass, two sport fish impacted by cormorant predation in eastern Lake Ontario.

  7. Connectivity of the Asiatic wild ass population in the Mongolian Gobi.

    Science.gov (United States)

    Kaczensky, Petra; Kuehn, Ralph; Lhagvasuren, Badamjav; Pietsch, Stephanie; Yang, Weikang; Walzer, Chris

    2011-02-01

    Long-distance migrations of wildlife have been identified as important biological phenomena, but their conservation remains a major challenge. The Mongolian Gobi is one of the last refuges for the Asiatic wild ass (Equus hemionus) and other threatened migratory mammals. Using historic and current distribution ranges, population genetics, and telemetry data we assessed the connectivity of the wild ass population in the context of natural and anthropogenic landscape features and the existing network of protected areas. In the Mongolian Gobi mean biomass production is highly correlated with human and livestock density and seems to predict wild ass occurrence at the upper level. The current wild ass distribution range largely falls into areas below the 250 gC/m(2)/year productivity isoline, suggesting that under the present land use more productive areas have become unavailable for wild asses. Population genetics results identified two subpopulations and delineated a genetic boundary between the Dzungarian and Transaltai Gobi for which the most likely explanation are the mountain ranges separating the two areas. Home ranges and locations of 19 radiomarked wild asses support the assumed restricting effects of more productive habitats and mountain ranges and additionally point towards a barrier effect of fences. Furthermore, telemetry data shows that in the Dzungarian and Transaltai Gobi individual wild ass rarely ventured outside of the protected areas, whereas in the southeast Gobi asses only spend a small fraction of their time within the protected area network. Conserving the continuity of the wild ass population will need a landscape level approach, also including multi-use landscapes outside of protected areas, particularly in the southeast Gobi. In the southwest Gobi, allowing for openings in the border fence to China and managing the border area as an ecological corridor would connect three large protected areas together covering over 70,000 km(2) of wild ass

  8. The Relationship of Body Length and Ratio Pappilla with Sex in Gobi Fish (Sicyopterus macrostetholepis

    Directory of Open Access Journals (Sweden)

    Rona Taula Sari

    2017-07-01

    Full Text Available Research about the relationship of body length and ratio papilla with sex in goby fish (S. macrostetholepis Blkr. has been done at Animal Structure and Developmental Laboratory, Biologi Department, Faculty of Matematics and Natural Sciences, Andalas University, Padang, which purposed to analyse the relationship of body length and ratio papilla with sex of goby fish (S. macrostetholepis Blkr.. The samples were taken in wild stream area at Batangkuranji river, Padang City. This research used descriptive method and data were analyzed by qualitatively and quantitatively. The results of investigation showed that in several goby fishes (S. macrostetholepis Blkr. with different sex had the same of body length and the same of ratio papilla. So, there was not relationship between of body length and ratio papilla with sex.  Goby fishes (S. macrostetholepis Blkr. it belongs to the hermaphrodite protogini, which the androgynous young females, while in adulthood, it would change sex to male. The results of this study are expected to add to the treasures of knowledge and information about reproductive gobies (S. macrostetholepis Blkr. in the preservation and development of fish farming.   

  9. The diet of reservoir perch before, during and after establishment of non-native tubenose goby

    Directory of Open Access Journals (Sweden)

    Všetičková Lucie

    2018-01-01

    Full Text Available In recent decades, gobiid species have increased their distribution throughout Europe and now often represent the dominant genus along many rivers and canals. In this study, we assessed the role of tubenose goby (Proterorhinus semilunaris as a prey species of native perch (Perca fluviatilis in a lowland reservoir soon after their initial introduction in 1994 (sampling started 1998 and 17 years after establishment (2011–2012. We compare these data with perch diet composition from before introduction (1981–1982. Our data indicate that tubenose gobies quickly became the dominant species along the reservoir bankside, making them an attractive prey for ≥1 + perch. There was a clear increasing trend in the numbers of larger perch caught along the rip-rap, with the largest fish clearly specialising on gobies. As such, introduction of tubenose gobies has had a pronounced effect on food web and population dynamics along the littoral zone. While goby numbers appear to have dropped significantly in recent years, apparently due to predation pressure, further studies are needed to assess whether such changes have had any general impact on population and food web dynamics within the reservoir.

  10. Invasion rate and population characteristics of the invasive round goby Neogobius melanostomus: effects of density and invasion history

    DEFF Research Database (Denmark)

    Azour, Farivar; Deurs, Mikael van; Behrens, Jane

    2015-01-01

    Round goby Neogobius melanostomus is currently one of the most wide-ranging invasive fish species in Europe and North America. The present study demonstrates how the distribution of round goby has expanded from 2008 to 2013 at a rate of about 30 km yr−1 along the Danish coastline in the western B...

  11. INVASION OF ROUND GOBY NEOGOBIUS MELANOSTOMUS (PALLAS, 1814 – ECO-THREAT OR ENVIROMENTAL ENRICHMENT?

    Directory of Open Access Journals (Sweden)

    Katarzyna Stepanowska

    2014-10-01

    Full Text Available Round goby Neogobius melanostomus (Pallas, 1814 is a fish species of Ponto-Caspian basin origin. However, since the second part of the 80’s of the last century has observed spreading of this species in European waters, including in Polish waters. In the last two decades, from 1990 when it was first caught of round goby near the fishing port in Hel, takes a massive and rapid spread of this fish throughout the Gulf of Gdańsk, Vistula Lagoon, along the southern Baltic coastal zone and the Pomeranian Bay and also the River Odra estuary. In 2009, first round goby in commercial catches conducted in Lake Dąbie was recorded. In this situation the question is that invasion can be a eco-threat or even enrichment of the environment to the human being?

  12. Gill remodelling during terrestrial acclimation reduces aquatic respiratory function of the amphibious fish Kryptolebias marmoratus.

    Science.gov (United States)

    Turko, Andy J; Cooper, Chris A; Wright, Patricia A

    2012-11-15

    The skin-breathing amphibious fish Kryptolebias marmoratus experiences rapid environmental changes when moving between water- and air-breathing, but remodelling of respiratory morphology is slower (~1 week). We tested the hypotheses that (1) there is a trade-off in respiratory function of gills displaying aquatic versus terrestrial morphologies and (2) rapidly increased gill ventilation is a mechanism to compensate for reduced aquatic respiratory function. Gill surface area, which varied inversely to the height of the interlamellar cell mass, was increased by acclimating fish for 1 week to air or low ion water, or decreased by acclimating fish for 1 week to hypoxia (~20% dissolved oxygen saturation). Fish were subsequently challenged with acute hypoxia, and gill ventilation or oxygen uptake was measured. Fish with reduced gill surface area increased ventilation at higher dissolved oxygen levels, showed an increased critical partial pressure of oxygen and suffered impaired recovery compared with brackish water control fish. These results indicate that hyperventilation, a rapid compensatory mechanism, was only able to maintain oxygen uptake during moderate hypoxia in fish that had remodelled their gills for land. Thus, fish moving between aquatic and terrestrial habitats may benefit from cutaneously breathing oxygen-rich air, but upon return to water must compensate for a less efficient branchial morphology (mild hypoxia) or suffer impaired respiratory function (severe hypoxia).

  13. Chronic exposure to paclobutrazol causes hepatic steatosis in male rockfish Sebastiscus marmoratus and the mechanism involved

    Energy Technology Data Exchange (ETDEWEB)

    Sun Lingbin [State Key Laboratory of Cellular Stress Biology, School of Life Sciences, Xiamen University, Xiamen (China); Li Jinshou [Department of Biological Engineering, Ningde Normal University, Ningde City, Fujian (China); Zuo Zhenghong [State Key Laboratory of Cellular Stress Biology, School of Life Sciences, Xiamen University, Xiamen (China); Chen Meng [State Key Laboratory of Marine Environmental Science, Xiamen University, Xiamen (China); Wang Chonggang, E-mail: cgwang@xmu.edu.cn [State Key Laboratory of Cellular Stress Biology, School of Life Sciences, Xiamen University, Xiamen (China); State Key Laboratory of Marine Environmental Science, Xiamen University, Xiamen (China)

    2013-01-15

    Paclobutrazol (PBZ) is a triazole-containing fungicide which is widely used in agriculture. Acute toxicity can follow its extensive use but it is generally weaker than traditional pesticides such as organochlorine and organophosphorus. However, its adverse effects on aquatic organisms need to be investigated. This study was conducted to investigate the effect of PBZ exposure on the hepatic lipid metabolism of Sebastiscus marmoratus. After PBZ exposure for 50 days, hepatic lipid droplets were enlarged and the hepatic total lipid, triglyceride, total cholesterol and free fatty acid content had increased in a dose dependent manner compared to the control. The mRNA expression of lipid metabolism associated genes such as peroxisome proliferator-activated receptors (PPARs), androgen receptor, acetyl-CoA carboxylase 1, fatty acid synthesis, fatty acid bing protein 4, liver X receptor {alpha} (LXR{alpha}) and stearoyl-CoA desaturase were up-regulated by PBZ exposure. These results indicated that triazole-containing fungicides might affect the metabolism and health of fish via the multi-signal pathways of nuclear receptors such as PPARs and LXR.

  14. Using dissolved carbon dioxide to alter the behavior of invasive round goby

    Science.gov (United States)

    Cupp, Aaron R.; Tix, John; Smerud, Justin R.; Erickson, Richard A.; Fredricks, Kim; Amberg, Jon J.; Suski, Cory D.; Wakeman, Robert

    2017-01-01

    Fisheries managers need effective methods to limit the spread of invasive round goby Neogobius melanostomus in North America. Elevating carbon dioxide (CO2) in water at pinch points of rivers (e.g., inside locks) is one approach showing potential to deter the passage of invasive fishes, such as bigheaded carps Hypophthalmichthys spp., but the effectiveness of this method to alter round goby behavior has not been determined. The goal for this study was to determine CO2 concentrations that alter round goby behavior across a range of water temperatures. Free-swimming avoidance (voluntary response) and loss of equilibrium (involuntary response) were quantified by exposing round goby to increasing CO2 concentrations at 5, 15, and 25 °C using a shuttle box choice arena and static tank. Water chemistry was measured concurrent with behavioral endpoints and showed that round goby avoided a threshold of 99–169 mg/L CO2(79,000–178,000 µatm) and lost equilibrium at 197–280 mg/L CO2 (163,000–303,000 µatm). Approximately 50% lower CO2 concentrations were found to modify behavior at 5 °C relative to 25 °C, suggesting greater effectiveness at lower water temperatures. We conclude that CO2 modified round goby behavior and concentrations determined in this study are intended to guide field testing of CO2 as an invasive fish deterrent.

  15. First stable isotope analysis of Asiatic wild ass tail hair from the Mongolian Gobi.

    Science.gov (United States)

    Horacek, Micha; Sturm, Martina Burnik; Kaczensky, Petra

    Stable isotope analysis has become a powerful tool to study feeding ecology, water use or movement pattern in contemporary, historic and ancient species. Certain hair and teeth grow continuously, and when sampled longitudinally can provide temporally explicit information on dietary regime and movement pattern. In an initial trial, we analysed a tail sample of an Asiatic wild ass ( Equus hemionus ) from the Mongolian Gobi. We found seasonal variations in H, C and N isotope patterns, likely being the result of temporal variations in available feeds, water supply and possibly physiological status. Thus stable isotope analysis shows promise to study the comparative ecology of the three autochthonous equid species in the Mongolian Gobi.

  16. Amended diagnosis and redescription of Pristimantis marmoratus (Boulenger, 1900 (Amphibia: Craugastoridae, with a description of its advertisement call and notes on its breeding ecology and phylogenetic relationships

    Directory of Open Access Journals (Sweden)

    Philippe J.R. Kok

    2018-01-01

    Full Text Available The frog Pristimantis marmoratus was originally described as Hylodes marmoratus by George A. Boulenger in 1900 based on a single specimen reported to have been collected at the foot of Mount Roraima in Guyana in 1898. We herein discuss the exact location of the type locality of P. marmoratus and provide a redescription of the species based on new material from Kaieteur National Park and from the slopes of Maringma-tepui in Guyana. We also describe the previously unknown vocalization and breeding ecology of the species, and conducted an exploratory molecular analysis of the phylogenetic relationships within the genus Pristimantis represented by the members of the “unistrigatus species group” in the Guiana Shield. Pristimantis marmoratus is a small-sized species mainly distinguished from its known Guiana Shield congeners by the combination of F I < II, SVL ≤ 20.4 in males, presence of vocal slits in males, granular/pustulate dorsal skin with well-developed scapular ridges, basal webbing between fingers, fringes on fingers and toes, crossed iris, diffuse yellow or pale green wash on groin, and absence of flashy colour on axillary/pre-axillary region. The advertisement call consists of a single note repeated at a rate of ca 11 calls/min with a dominant frequency ranging from 2756 to 3101 Hz. Pristimantis marmoratus is primarily arboreal, exclusively active at dusk, and probably restricted to the pristine rainforests of the Pantepui uplands and highlands, east of the Gran Sabana between ca 600 and 1800 m above sea level. Preliminary molecular analyses recovered Pristimantis marmoratus as sister to an unnamed species from the Eastern Guiana Shield. On grounds of the newly established distributional extent we suggest maintaining the IUCN conservation status as Least Concern.

  17. Life cycle of the pelagic goby Aphia minuta (Pisces: Gobiidae

    Directory of Open Access Journals (Sweden)

    M. Iglesias

    2001-09-01

    Full Text Available Reproductive aspects of the transparent goby Aphia minuta (n=2977, 14-45 mm total length (TL were studied in Majorcan waters, western Mediterranean, during the fishing season (December to April from 1985 to 1993. Male:female sex ratio was 1:1. Size at first maturity was 38 mm TL for females and 34 mm TL for males. Oocyte size-frequency distribution indicated that A. minuta is a single spawner. Fecundity of A. minuta ranged from 935 to 2648 oocytes. The breeding season extended from December to April with a peak in March. After a single reproduction at 5-6 months of age, most of the specimens disappeared from the fishing areas. Recruitment to the fishing area occurred in late December and early January (14-24 mm TL, age 2-3 months. On the other hand, the hatch date back-calculated from the age in days and the date of capture of individuals of A. minuta during the fishing season, indicated a spawning peak in autumn (September-October, six months after the peak of observed spawning. Schools of A. minuta were detected by acoustic methods, during the fishing season (winter-spring in fishing areas (5-40 m depth, principally inside bays, and during the rest of the year (summer and autumn in deeper areas (40-90 m, outside bays, with water temperatures between 13 and 16ºC and a high seasonal productivity in each depth range. Therefore, we propose that A. minuta has two annual cohorts in the western Mediterranean, corresponding to two main spawning in spring and autumn, respectively. Life history pattern indicated that we only know the winter cohort resulting from the autumn spawning. Meanwhile the summer cohort (spring spawning grows and reproduces in deeper areas not being targeted by the fishery. Indirect validation is provided from information from other areas. The relevance of the life cycle is discussed in relation to fishery management.

  18. The role of dyadic interactions in the mixed-mating strate-gies of the mangrove rivulus Kryptolebias marmoratus

    Directory of Open Access Journals (Sweden)

    Kelly N. LUKE,David L. BECHLER

    2010-02-01

    Full Text Available The mangrove rivulus Kryptolebias marmoratus a small cyprinodont fish native to tropical and subtropical waters from Florida to Brazil, is one of two known self-fertilizing, hermaphroditic vertebrates of which K. marmoratus displays androdioecy, a complex system of reproduction in which hermaphrodites and males are present. This study describes the behavioral repertoires observed during dyadic interactions in the laboratory. Kryptolebias marmoratus exhibited 23 distinctive acts or behaviors. Acts were divided into four categories: aggressive, submissive, neutral, and reproductive. Leading and following behaviors played important roles in the behavioral repertoires of these fish. In hermaphrodite-male dyads, males exclusively initiated the reproductive process and actively pursued hermaphrodites. When hermaphrodites were paired, there was no evidence that they behaved like other simultaneous hermaphrodites that alternate sexual roles (e.g. serranids. Hermaphrodites were extremely aggressive towards one another, and the aggressor established dominance rapidly. Male-male dyads were divided into two subdivisions based on the presence or absence of the caudal ocellus on one fish. A caudal ocellus on one male appeared to signal the possibility of a potential mating partner to males lacking it. Pairings of males without an ocellus were similar to hermaphrodite-hermaphrodite dyads in that both members of the pair were aggressive towards one another. These observations may be indicative of interactions taking place in natural communities or assemblages of fish in which both males and hermaphrodites occur and provide evidence on the role of dyadic interactions in the mixed-mating strategies [Current Zoology 56 (1: 6–17 2010].

  19. Ontogeny of the morphology-performance axis in an amphibious fish (Kryptolebias marmoratus).

    Science.gov (United States)

    Styga, Joseph M; Houslay, Thomas M; Wilson, Alastair J; Earley, Ryan L

    2017-12-01

    Establishing links between morphology and performance is important for understanding the functional, ecological, and evolutionary implications of morphological diversity. Relationships between morphology and performance are expected to be age dependent if, at different points during ontogeny, animals must perform in different capacities to achieve high fitness returns. Few studies have examined how the relationship between form and function changes across ontogeny. Here, we assess this relationship in the amphibious mangrove rivulus (Kryptolebias marmoratus) fish, a species that is both capable of and reliant on "tail-flip jumping" for terrestrial locomotion. Tail-flip jumping entails an individual transferring its weight to the caudal region of the body, launching itself from the substrate to navigate to new aquatic or semi-aquatic habitats. By combining repeated trials of jumping performance in 237 individuals from distinct age classes with a clearing and staining procedure to visualize bones in the caudal region, we test the hypotheses that as age increases (i) average jumping performance (body lengths jumped) will increase, (ii) the amount of variation for each trait will change, and (iii) the patterns of covariation/correlation among traits, which tell us about the integration of form with function, will also change. We find a significant increase in size-adjusted jumping performance with age, and modification to the correlation structure among traits across ontogeny. However, we also find that significant links between form and function evident in young animals disappear at later ontogenetic stages. Our study suggests that different functional mechanisms may be associated with high performance at different stages of development. © 2018 Wiley Periodicals, Inc.

  20. Testing the effectiveness of automated acoustic sensors for monitoring vocal activity of Marbled Murrelets Brachyramphus marmoratus

    Science.gov (United States)

    Cragg, Jenna L.; Burger, Alan E.; Piatt, John F.

    2015-01-01

    Cryptic nest sites and secretive breeding behavior make population estimates and monitoring of Marbled Murrelets Brachyramphus marmoratus difficult and expensive. Standard audio-visual and radar protocols have been refined but require intensive field time by trained personnel. We examined the detection range of automated sound recorders (Song Meters; Wildlife Acoustics Inc.) and the reliability of automated recognition models (“recognizers”) for identifying and quantifying Marbled Murrelet vocalizations during the 2011 and 2012 breeding seasons at Kodiak Island, Alaska. The detection range of murrelet calls by Song Meters was estimated to be 60 m. Recognizers detected 20 632 murrelet calls (keer and keheer) from a sample of 268 h of recordings, yielding 5 870 call series, which compared favorably with human scanning of spectrograms (on average detecting 95% of the number of call series identified by a human observer, but not necessarily the same call series). The false-negative rate (percentage of murrelet call series that the recognizers failed to detect) was 32%, mainly involving weak calls and short call series. False-positives (other sounds included by recognizers as murrelet calls) were primarily due to complex songs of other bird species, wind and rain. False-positives were lower in forest nesting habitat (48%) and highest in shrubby vegetation where calls of other birds were common (97%–99%). Acoustic recorders tracked spatial and seasonal trends in vocal activity, with higher call detections in high-quality forested habitat and during late July/early August. Automated acoustic monitoring of Marbled Murrelet calls could provide cost-effective, valuable information for assessing habitat use and temporal and spatial trends in nesting activity; reliability is dependent on careful placement of sensors to minimize false-positives and on prudent application of digital recognizers with visual checking of spectrograms.

  1. Modeling marbled murrelet (Brachyramphus marmoratus) habitat using LiDAR-derived canopy data

    Science.gov (United States)

    Hagar, Joan C.; Eskelson, Bianca N.I.; Haggerty, Patricia K.; Nelson, S. Kim; Vesely, David G.

    2014-01-01

    LiDAR (Light Detection And Ranging) is an emerging remote-sensing tool that can provide fine-scale data describing vertical complexity of vegetation relevant to species that are responsive to forest structure. We used LiDAR data to estimate occupancy probability for the federally threatened marbled murrelet (Brachyramphus marmoratus) in the Oregon Coast Range of the United States. Our goal was to address the need identified in the Recovery Plan for a more accurate estimate of the availability of nesting habitat by developing occupancy maps based on refined measures of nest-strand structure. We used murrelet occupancy data collected by the Bureau of Land Management Coos Bay District, and canopy metrics calculated from discrete return airborne LiDAR data, to fit a logistic regression model predicting the probability of occupancy. Our final model for stand-level occupancy included distance to coast, and 5 LiDAR-derived variables describing canopy structure. With an area under the curve value (AUC) of 0.74, this model had acceptable discrimination and fair agreement (Cohen's κ = 0.24), especially considering that all sites in our sample were regarded by managers as potential habitat. The LiDAR model provided better discrimination between occupied and unoccupied sites than did a model using variables derived from Gradient Nearest Neighbor maps that were previously reported as important predictors of murrelet occupancy (AUC = 0.64, κ = 0.12). We also evaluated LiDAR metrics at 11 known murrelet nest sites. Two LiDAR-derived variables accurately discriminated nest sites from random sites (average AUC = 0.91). LiDAR provided a means of quantifying 3-dimensional canopy structure with variables that are ecologically relevant to murrelet nesting habitat, and have not been as accurately quantified by other mensuration methods.

  2. Tetrodotoxin poisoning caused by Goby fish consumption in southeast China: a retrospective case series analysis

    Directory of Open Access Journals (Sweden)

    Jie You

    2015-01-01

    Full Text Available OBJECTIVES: To investigate an unusual outbreak of tetrodotoxin poisoning in Leizhou, southeast China, a case series analysis was conducted to identify the source of illness. METHODS: A total of 22 individuals experienced symptoms of poisoning, including tongue numbness, dizziness, nausea and limb numbness and weakness. Two toxic species, Amoya caninus and Yongeichthys nebulosus, were morphologically identified from the batches of gobies consumed by the patients. Tetrodotoxin levels in the blood and Goby fish samples were detected using liquid chromatography-tandem mass spectrometry. RESULTS: The tetrodotoxin levels in the remaining cooked Goby fish were determined to be 2090.12 µg/kg. For Amoya caninus, the toxicity levels were 1858.29 µg/kg in the muscle and 1997.19 µg/kg in the viscera and for Yongeichthys nebulosus, they were 2783.00 µg/kg in the muscle and 2966.21 µg/kg in the viscera. CONCLUSION: This outbreak demonstrates an underestimation of the risk of Goby fish poisoning. Furthermore, the relationships among the toxic species, climates and marine algae present should be clarified in the future.

  3. Pastoral community organization, livelihoods and biodiversity conservation in Mongolia's Southern Gobi Region

    Science.gov (United States)

    Sabine M. Schmidt

    2006-01-01

    In this paper I describe processes and impacts of collective action by mobile pastoralist communities, and of external support strategies to strengthen local institutions and cooperation in Mongolia’s southern Gobi. The need for pastoral mobility triggered the processes leading to community organization, and the emergence, or re-emergence, of local informal...

  4. 78 FR 8745 - Endangered and Threatened Wildlife and Plants; Designation of Critical Habitat for Tidewater Goby

    Science.gov (United States)

    2013-02-06

    ... the Tidewater Goby (Service 2005a; Recovery Plan). The basis for our action. Under the Act, we must... units in California (73 FR 5920, January 31, 2008). The lawsuit challenged the Service's failure to... to our Recovery Plan (Service 2005a), which is available from the Ventura Fish and Wildlife Office...

  5. First records of reproductive behaviour and early development of the bearded goby Sufflogobius bibarbatus.

    Science.gov (United States)

    Skrypzeck, H; Salvanes, A G V; Currie, B; Kotze, A

    2014-04-01

    Data on developmental characteristics from fertilization to 2 days post-hatching during captivity of the anoxia tolerant bearded goby Sufflogobius bibarbatus, one of the keystone prey species for many of the commercial fish populations, sea mammals and birds in south-west Africa, are presented. © 2014 The Fisheries Society of the British Isles.

  6. Non-native gobies facilitate the transmission of Bucephalus polymorphus (Trematoda)

    Czech Academy of Sciences Publication Activity Database

    Ondračková, Markéta; Hudcová, Iveta; Dávidová, Martina; Adámek, Zdeněk; Kašný, M.; Jurajda, Pavel

    2015-01-01

    Roč. 8, č. 1 (2015), s. 382 ISSN 1756-3305 R&D Projects: GA ČR(CZ) GAP505/12/2569 Institutional support: RVO:68081766 Keywords : Bucephalus polymorphus * Complex life cycle * Goby * Infectivity * Intermediate host * Non-native species * Trematode Subject RIV: EH - Ecology, Behaviour Impact factor: 3.234, year: 2015

  7. Every drop counts: Interview with awardee Gabin Koto N'Gobi ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    2012-05-11

    May 11, 2012 ... While artificial dew collection methods already exist, Koto N'Gobi ... The good news is that the condenser harvests up to 4L of water per ... “For example, at the Guene primary school, there is no water point for the students.

  8. Environment not "nativeness" dictates reproductive trait shifts in Ponto-Caspian gobies

    Czech Academy of Sciences Publication Activity Database

    Konečná, Markéta; Janáč, Michal; Roche, Kevin Francis; Jurajda, Pavel

    2016-01-01

    Roč. 25, č. 1 (2016), s. 167-170 ISSN 0906-6691 R&D Projects: GA ČR(CZ) GAP505/11/1768 Institutional support: RVO:68081766 Keywords : Pseudorasbora parva * invasive plants * populations * invader * range * goby Subject RIV: EG - Zoology Impact factor: 2.054, year: 2016

  9. First record of Pontian monkey goby, Neogobius fluviatilis (Pallas, 1814), in the Dutch Rhine

    NARCIS (Netherlands)

    Van Kessel, N.; Dorenbosch, M.; Spikmans, F.

    2009-01-01

    The Pontian monkey goby, Neogobius fluviatilis, was recorded for the first time in the Netherlands in March 2009. Seven specimens were caught in the lower parts of the River Rhine, at close distance of the German border. Based on the species invasive history, N. fluviatilis could become invasive.

  10. Urban particle size distributions during two contrasting dust events originating from Taklimakan and Gobi Deserts

    International Nuclear Information System (INIS)

    Zhao, Suping; Yu, Ye; Xia, Dunsheng; Yin, Daiying; He, Jianjun; Liu, Na; Li, Fang

    2015-01-01

    The dust origins of the two events were identified using HYSPLIT trajectory model and MODIS and CALIPSO satellite data to understand the particle size distribution during two contrasting dust events originated from Taklimakan and Gobi deserts. The supermicron particles significantly increased during the dust events. The dust event from Gobi desert affected significantly on the particles larger than 2.5 μm, while that from Taklimakan desert impacted obviously on the particles in 1.0–2.5 μm. It is found that the particle size distributions and their modal parameters such as VMD (volume median diameter) have significant difference for varying dust origins. The dust from Taklimakan desert was finer than that from Gobi desert also probably due to other influencing factors such as mixing between dust and urban emissions. Our findings illustrated the capacity of combining in situ, satellite data and trajectory model to characterize large-scale dust plumes with a variety of aerosol parameters. - Highlights: • Dust particle size distributions had large differences for varying origins. • Dust originating from Taklimakan Desert was finer than that from Gobi Desert. • Effect of dust on the supermicron particles was obvious. • PM_1_0 concentrations increased by a factor of 3.4–25.6 during the dust event. - Dust particle size distributions had large differences for varying origins, which may be also related to other factors such as mixing between dust and urban emissions.

  11. Can round goby (Neogobius melanostomus) caught by rod and line be used for diet analysis?

    Czech Academy of Sciences Publication Activity Database

    Jurajda, Pavel; Všetičková, Lucie; Polačik, Matej; Vassilev, M.

    2013-01-01

    Roč. 39, č. 1 (2013), s. 182-185 ISSN 0380-1330 R&D Projects: GA ČR(CZ) GAP505/11/1768 Institutional support: RVO:68081766 Keywords : Neogobius melanostomus * Gobies * Danube * Diet * Sampling methodology * Selectivity Subject RIV: EH - Ecology, Behaviour Impact factor: 1.771, year: 2013

  12. Lithospheric controls on crustal reactivation and intraplate mountain building in the Gobi Corridor, Central Asia

    Science.gov (United States)

    Cunningham, D.

    2017-12-01

    This talk will review the Permian-Recent tectonic history of the Gobi Corridor region which includes the actively deforming Gobi Altai-Altai, Eastern Tien Shan, Beishan and North Tibetan foreland. Since terrane amalgamation in the Permian, Gobi Corridor crust has been repeatedly reactivated by Triassic-Jurassic contraction/transpression, Late Cretaceous extension and Late Cenozoic transpression. The tectonic history of the region suggests the following basic principle for intraplate continental regions: non-cratonized continental interior terrane collages are susceptible to repeated intraplate reactivation events, driven by either post-orogenic collapse and/or compressional stresses derived from distant plate boundary convergence. Thus, important related questions are: 1) what lithospheric pre-conditions favor intraplate crustal reactivation in the Gobi Corridor (simple answer: crustal thinning, thermal weakening, strong buttressing cratons), 2) what are the controls on the kinematics of deformation and style of mountain building in the Gobi-Altai-Altai, Beishan and North Tibetan margin (simple answer: many factors, but especially angular relationship between SHmax and `crustal grain'), 3) how does knowledge of the array of Quaternary faults and the historical earthquake record influence our understanding of modern earthquake hazards in continental intraplate regions (answer: extrapolation of derived fault slip rates and recurrence interval determinations are problematic), 4) what important lessons can we learn from the Mesozoic-Cenozoic tectonic history of Central Asia that is applicable to the tectonic evolution of all intraplate continental regions (simple answer: ancient intraplate deformation events may be subtly expressed in the rock record and only revealed by low-temperature thermochronometers, preserved orogen-derived sedimentary sequences, fault zone evidence for younger brittle reactivation, and recognition of a younger class of cross-cutting tectonic

  13. Genetic composition of laboratory stocks of the self-fertilizing fish Kryptolebias marmoratus: a valuable resource for experimental research.

    Directory of Open Access Journals (Sweden)

    Andrey Tatarenkov

    2010-09-01

    Full Text Available The hermaphroditic Mangrove Killifish, Kryptolebias marmoratus, is the world's only vertebrate that routinely self-fertilizes. As such, highly inbred and presumably isogenic "clonal" lineages of this androdioecious species have long been maintained in several laboratories and used in a wide variety of experiments that require genetically uniform vertebrate specimens. Here we conduct a genetic inventory of essentially all laboratory stocks of the Mangrove Killifish held worldwide. At 32 microsatellite loci, these stocks proved to show extensive interline differentiation as well as some intraline variation, much of which can be attributed to post-origin de novo mutations and/or to the segregation of polymorphisms from wild progenitors. Our genetic findings also document that many of the surveyed laboratory strains are not what they have been labeled, apparently due to the rather frequent mishandling or unintended mixing of various laboratory stocks over the years. Our genetic inventory should help to clarify much of this confusion about the clonal identities and genetic relationships of laboratory lines, and thereby help to rejuvenate interest in K. marmoratus as a reliable vertebrate model for experimental research that requires or can capitalize upon "clonal" replicate specimens.

  14. Morphological differences in the skin of marble trout Salmo marmoratus and of brown trout Salmo trutta

    Directory of Open Access Journals (Sweden)

    Urška Sivka

    2012-07-01

    Full Text Available Despite being genetically very closely related, the marble trout Salmo marmoratus and the brown trout Salmo trutta exhibit marked phenotypic differences, particularly with regard to skin pigmentation. Histological analysis of skin from the head and gill cover of differently aged individuals of the two species was carried out in order to characterize differences in skin structure. The basic structure of skin of the individuals studied corresponded with that described for other salmonids, though the head epidermis was somewhat thicker in S. marmoratus than in S. trutta, thickening with age in both species. Numerous secretory goblet cells and sporadic secretory sacciform cells were observed in the upper and middle part of the epidermis in both species. Melanophores were present in both species only in the dermis, and were bigger in S. marmoratus and present at lower average density than in S. trutta, and more or less constant across all age classes. In adult S. marmoratus with fully established marble pigmentation, light areas at low density with small (i.e. aggregated melanophores were present, while in S. trutta melanophores were more uniformly distributed.

  15. Satellite Monitoring of Vegetation Response to Precipitation and Dust Storm Outbreaks in Gobi Desert Regions

    Directory of Open Access Journals (Sweden)

    Yuki Sofue

    2018-02-01

    Full Text Available Recently, droughts have become widespread in the Northern Hemisphere, including in Mongolia. The ground surface condition, particularly vegetation coverage, affects the occurrence of dust storms. The main sources of dust storms in the Asian region are the Taklimakan and Mongolian Gobi desert regions. In these regions, precipitation is one of the most important factors for growth of plants especially in arid and semi-arid land. The purpose of this study is to clarify the relationship between precipitation and vegetation cover dynamics over 29 years in the Gobi region. We compared the patterns between precipitation and Normalized Difference Vegetation Index (NDVI for a period of 29 years. The precipitation and vegetation datasets were examined to investigate the trends during 1985–2013. Cross correlation analysis between the precipitation and the NDVI anomalies was performed. Data analysis showed that the variations of NDVI anomalies in the east region correspond well with the precipitation anomalies during this period. However, in the southwest region of the Gobi region, the NDVI had decreased regardless of the precipitation amount, especially since 2010. This result showed that vegetation in this region was more degraded than in the other areas.

  16. Evidence for ontogenetically and morphologically distinct alternative reproductive tactics in the invasive Round Goby Neogobius melanostomus.

    Science.gov (United States)

    Bleeker, Katinka; de Jong, Karen; van Kessel, Nils; Hinde, Camilla A; Nagelkerke, Leopold A J

    2017-01-01

    Alternative reproductive tactics are characterized by the occurrence of discrete alternative morphs that differ in behavioural, morphological and physiological traits within the same sex. Although much effort has been made to describe the behaviour, morphology and physiology of such alternative morphs, less effort has been invested investigating how much overlap there is in the characteristics of such morphs in natural populations. We studied random population samples of the invasive Round Goby Neogobius melanostomus from five different localities in the river Rhine system in the Netherlands. We found two morphologically and physiologically distinct male morphs which likely represent alternative reproductive tactics. Almost all mature males under 9.35 cm total length had a gonadosomatic index > 3%, suggestive of a sneaker tactic, while nearly all males above 9.35 cm has a gonadosomatic index of sneaker morphs would be ca. 7.5 times as high as the gonad mass of parental morphs of the same total length after extrapolation. Few (9%) intermediates were found, suggesting that the expression of alternative reproductive tactics is determined before the first breeding season. This contrasts with studies on other goby species, which show evidence of plastic tactics that can be affected by social circumstances. We conclude that it is possible to distinguish two alternative male morphs in the Dutch Round Goby population using morphological measurements alone. Although behavioural observations are needed to provide conclusive evidence, the difference in GSI between these morphs indicates that these morphs reflect alternative reproductive tactics.

  17. Twenty five years of invasion: management of the round goby Neogobius melanostomus in the Baltic Sea

    DEFF Research Database (Denmark)

    Ojaveer, Henn; Galil, Bella S.; Lehtiniemi, Maiju

    2015-01-01

    The round goby, Neogobius melanostomus (Pallas, 1814), is one of the most invasive non-indigenous species in the Baltic Sea. It dominates coastal fisheries in some localities and is frequently found in offshore pelagic catches. This paper identifies management issues and suggests actions to be co......The round goby, Neogobius melanostomus (Pallas, 1814), is one of the most invasive non-indigenous species in the Baltic Sea. It dominates coastal fisheries in some localities and is frequently found in offshore pelagic catches. This paper identifies management issues and suggests actions...... to be considered for post-invasion management. Priority should be given to the establishment of a coordinated pan-Baltic monitoring programme and associated data storage and exchange, as well as the compilation of landing statistics of the round goby in commercial and recreational fisheries. While eradication...... is unrealistic, population control that leads to minimising the risk of transfer to yet uncolonised areas in the Baltic Sea and adjacent waterbodies is feasible. This should comprise the requirement that the species be landed in commercial fishery bycatch, the management of ships’ ballast water and sediments...

  18. Invasion strategies in round goby (Neogobius melanostomus: Is bigger really better?

    Directory of Open Access Journals (Sweden)

    Joerg Brandner

    Full Text Available Few studies have systematically investigated mid- or long-term temporal changes of biological characteristics in invasive alien species considering the different phases of an invasion. We studied the invasion performance of one of the most invasive species worldwide, the round goby Neogobius melanostomus, from total absence over first occurrence until establishment from 2010 to 2015 in the upper Danube River. After an upstream movement of the invasion front of about 30 river km within four years, the pattern that round goby pioneering populations significantly differ from longer established ones has been confirmed: Pioneering populations at the invasion front comprised more females than males, and adult specimens with a larger body size compared to those at longer inhabited areas. On the population-level, the proportion of juveniles increased with time since invasion. The results of this study provide support for the previously postulated ´bigger is better´ and ´individual trait utility´ hypotheses explaining invasion success in round goby. Pioneering invaders with their greater exploratory behavior, highly adaptive phenotypic plasticity and increased competitive ability seem to act as prime emperors of new habitats, strongly following and benefiting from man-made river-bank structures.

  19. New BRDF Model for Desert and Gobi Using Equivalent Mirror Plane Method, Establishment and Validation

    Science.gov (United States)

    Li, Y.; Rong, Z.

    2017-12-01

    The surface Bidirectional Reflectance Distribution Function (BRDF) is a key parameter that affects the vicarious calibration accuracy of visible channel remote sensing instrument. In the past 30 years, many studies have been made and a variety of models have been established. Among them, the Ross-li model was highly approved and widely used. Unfortunately, the model doesn't suitable for desert and Gobi quite well because of the scattering kernel it contained, needs the factors such as plant height and plant spacing. A new BRDF model for surface without vegetation, which is mainly used in remote sensing vicarious calibration, is established. That was called Equivalent Mirror Plane (EMP) BRDF. It is used to characterize the bidirectional reflectance of the near Lambertian surface. The accuracy of the EMP BRDF model is validated by the directional reflectance data measured on the Dunhuang Gobi and compared to the Ross-li model. Results show that the regression accuracy of the new model is 0.828, which is similar to the Ross-li model (0.825). Because of the simple form (contains only four polynomials) and simple principle (derived by the Fresnel reflection principle, don't include any vegetation parameters), it is more suitable for near Lambertian surface, such as Gobi, desert, Lunar and reference panel. Results also showed that the new model could also maintain a high accuracy and stability in sparse observation, which is very important for the retrieval requirements of daily updating BRDF remote sensing products.

  20. Emersion behaviour underlies variation in gill morphology and aquatic respiratory function in the amphibious fish Kryptolebias marmoratus.

    Science.gov (United States)

    Turko, A J; Tatarenkov, A; Currie, S; Earley, R L; Platek, A; Taylor, D S; Wright, P A

    2018-04-13

    Fishes acclimated to hypoxic environments often increase gill surface area to improve O 2 uptake. In some species, surface area is increased via reduction of an interlamellar cell mass (ILCM) that fills water channels between gill lamellae. Amphibious fishes, however, may not increase gill surface area in hypoxic water because these species can, instead, leave water and breathe air. To differentiate between these possibilities, we compared wild amphibious mangrove rivulus Kryptolebias marmoratus from two habitats that varied in O 2 availability - a hypoxic freshwater pool versus nearly anoxic crab burrows. Fish captured from crab burrows had less gill surface area (as ILCMs were enlarged by ∼32%), increased rates of normoxic O 2 consumption and increased critical O 2 tension compared with fish from the freshwater pool. Thus, wild mangrove rivulus do not respond to near-anoxic water by decreasing metabolism or increasing O 2 extraction. Instead, fish from the crab burrow habitat spent three times longer out of water, which probably caused the observed changes in gill morphology and respiratory phenotype. We also tested whether critical O 2 tension is influenced by genetic heterozygosity, as K. marmoratus is one of only two hermaphroditic vertebrate species that can produce both self-fertilized (inbred) or out-crossed (more heterozygous) offspring. We found no evidence for inbreeding depression, suggesting that self-fertilization does not impair respiratory function. Overall, our results demonstrate that amphibious fishes that inhabit hypoxic aquatic habitats can use a fundamentally different strategy from that used by fully aquatic water-breathing fishes, relying on escape behaviour rather than metabolic depression or increased O 2 extraction ability. © 2018. Published by The Company of Biologists Ltd.

  1. Characterization of vitellogenin gene expression in round goby (Neogobius melanostomus) using a quantitative polymerase chain reaction assay.

    Science.gov (United States)

    Bowley, Lucas A; Alam, Farhana; Marentette, Julie R; Balshine, Sigal; Wilson, Joanna Y

    2010-12-01

    A growing concern over endocrine disruption in aquatic species has prompted the development of molecular assays to monitor environmental impacts. This study describes the development of quantitative polymerase chain reaction (qPCR) assays to characterize the expression of two vitellogenin (Vtg) genes in the invasive round goby (Neogobius melanostomus). Fragments from the 18SrRNA (housekeeping gene), Vtg II, and Vtg III genes were cloned and sequenced. The qPCR assays were developed to detect hepatic Vtg expression in goby. The assays detected induction of both Vtg genes in nonreproductive males following a two-week laboratory exposure to 17β-estradiol (≥1 mg/kg i.p. injection). The assays were applied to goby from Hamilton Harbour, Lake Ontario (Canada), including those from sites where feminization and intersex of goby has been documented. Both Vtg genes had significantly higher expression in females compared to males. Male reproductive goby adopt either parental or sneaker tactics; Vtg II expression was higher in sneaker than in parental males but parental and nonreproductive males did not differ from each other. The Vtg III expression was significantly higher in sneaker males followed by parental males and nonreproductive males, respectively. The Vtg II and III expression in nonreproductive males was elevated in the contaminated site with documented intersex. This assay provides an important tool for the use of an invasive species in monitoring endocrine disruption in the Great Lakes region. Copyright © 2010 SETAC.

  2. Effects of increasing temperature due to aquatic climate change on the self-fertility and the sexual development of the hermaphrodite fish, Kryptolebias marmoratus.

    Science.gov (United States)

    Park, Chang-Beom; Kim, Young Jun; Soyano, Kiyoshi

    2017-01-01

    In order to assess the effects of increasing temperature on the reproductive performance of fish, different thermal conditions (i.e., 25.0, 26.5, 27.5, 28.5, 30.0 °C) were used in this study and the self-fertilizing hermaphrodite fish, Kryptolebias marmoratus, was exposed to these different thermal conditions. During an exposure period of 30 to 150 days, the gonadosomatic index (GSI), gonadal development, the levels of plasma 17β-estradial (E2) and testosterone (T), hepatic vitellogenin (VTG) mRNA abundance, and the number of self-fertilized eggs were analyzed. This study confirmed that a high water temperature above 27.5 °C led to the suppression of self-fertility of hermaphroditic fish from 30 days after exposure. The oocyte quality and maturation would be affected by the disruption of hepatic VTG synthesis at a high water temperature of 30 °C, which resulted in the reduced the self-fertility in K. marmoratus. Consequently, this study suggests that elevated water temperature due to aquatic climate change prior to sexual maturation and the onset of spawning can lead to the reproductive dysfunction of hermaphroditic K. marmoratus.

  3. Status review of the Marbled Murrelet (Brachyramphus marmoratus) in Alaska and British Columbia

    Science.gov (United States)

    Piatt, John F.; Kuletz, K.J.; Burger, A.E.; Hatch, Shyla A.; Friesen, Vicki L.; Birt, T.P.; Arimitsu, Mayumi L.; Drew, G.S.; Harding, A.M.A.; Bixler, K.S.

    2007-01-01

    The Marbled Murrelet (Brachyramphus marmoratus) is a small, diving seabird inhabiting inshore waters of the Northeastern Pacific Ocean. This species feeds on small, schooling fishes and zooplankton, and nests primarily on the moss-covered branches of large, old-growth conifers, and also, in some parts of its range, on the ground. We reviewed existing information on this species to evaluate its current status in the northern part of its range-Alaska (U.S.) and British Columbia (Canada). Within the southern part of its range (Washington, Oregon, and California, U.S.), the Marbled Murrelet was listed as a threatened species under the Endangered Species Act (ESA) in 1993, and the U.S. Fish and Wildlife Service (USFWS) needed information on the species throughout its range for ESA deliberations. We compiled published information on the conservation status, population biology, foraging ecology, population genetics, population status and trends, demography, marine and nesting habitat characteristics, threats, and ongoing conservation efforts for Marbled Murrelets in Alaska and British Columbia. We conducted a new genetic study using samples from a segment of the range that had not been included in previous studies (Washington, Oregon) and additional nuclear intron and microsatellite markers. We also analyzed available at-sea survey data from several locations for trend. To understand the reasonableness of the empirical trend data, we developed demographic models incorporating stochasticity to discern what population trends were possible by chance. The genetic studies substantially confirmed previous findings on population structure in the Marbled Murrelet. Our present work finds three populations: (1) one comprising birds in the central and western Aleutian Islands; (2) one comprising birds in central California; and (3) one comprising birds within the center of the range from the eastern Aleutians to northern California. Our knowledge of genetic structure within this

  4. Environmental DNA (eDNA): A tool for quantifying the abundant but elusive round goby (Neogobius melanostomus)

    Science.gov (United States)

    Nevers, Meredith; Byappanahalli, Muruleedhara; Morris, Charles C.; Shively, Dawn; Przybyla-Kelly, Katarzyna; Spoljaric, Ashley M.; Dickey, Joshua; Roseman, Edward

    2018-01-01

    Environmental DNA (eDNA) is revolutionizing biodiversity monitoring, occupancy estimates, and real-time detections of invasive species. In the Great Lakes, the round goby (Neogobius melanostomus), an invasive benthic fish from the Black Sea, has spread to encompass all five lakes and many tributaries, outcompeting or consuming native species; however, estimates of round goby abundance are confounded by behavior and habitat preference, which impact reliable methods for estimating their population. By integrating eDNA into round goby monitoring, improved estimates of biomass may be obtainable. We conducted mesocosm experiments to estimate rates of goby DNA shedding and decay. Further, we compared eDNA with several methods of traditional field sampling to compare its use as an alternative/complementary monitoring method. Environmental DNA decay was comparable to other fish species, and first-order decay was lower at 12°C (k = 0.043) than at 19°C (k = 0.058). Round goby eDNA was routinely detected in known invaded sites of Lake Michigan and its tributaries (range log10 4.8–6.2 CN/L), but not upstream of an artificial fish barrier. Traditional techniques (mark-recapture, seining, trapping) in Lakes Michigan and Huron resulted in fewer, more variable detections than eDNA, but trapping and eDNA were correlated (Pearson R = 0.87). Additional field testing will help correlate round goby abundance with eDNA, providing insight on its role as a prey fish and its impact on food webs.

  5. The effect of meal size on gastric evacuation in whiting

    DEFF Research Database (Denmark)

    Andersen, Niels Gerner

    1998-01-01

    Gastric evacuation experiments were performed on whiting Merlangius merlangus fed discrete meals of different sizes. Herring Clupea harengus, sandeel Ammodytes tobianus, common goby Pomatoschistus microps, and brown shrimp Crangon crangon were tested as prey. A simple power model to describe...

  6. Reproductive tactics of male bearded goby (Sufflogobius bibarbatus) in anoxic and hypoxic waters

    Science.gov (United States)

    Seivåg, Maria Larsen; Salvanes, Anne Gro Vea; Utne-Palm, Anne Christine; Kjesbu, Olav Si'gurd

    2016-03-01

    The bearded goby (Sufflogobius bibarbatus), a key species in the northern Benguela Upwelling Ecosystem, tolerates extremely low levels of oxygen. Yet little is known about how its reproduction is affected by these harsh living conditions. The distribution patterns of alternative reproductive tactics of male bearded goby across the continental shelf off Namibia were investigated. Histology and stereology were for the first time used to validate macroscopic maturity development by estimating volume fraction of the different stages of spermatogenesis using "Delesse principle", an approach so far for teleosts barely used in studies on testes but applied in advanced oocyte estimation. The macroscopic scale appeared suitable for the purpose, and the prevalence of territorial and sneaker tactics could therefore be documented. The sneakers had relative large testes and small seminal vesicles (SV), with the opposite being the case for the territorials. A third, numerous category with intermediate sized testes and SV was also recognized with unclear underlying tactical rationale, although regression analyses indicated similar investment in testes weight in relation to somatic weight as for the territorials. Low oxygen levels were the most important factor limiting spawning activity in territorial males. Our data suggested the existence of a spawning site on the outer shelf of the central Namibian shelf where the bottom water is hypoxic (oxygen saturation of 6.2-6.7%) while the anoxic middle shelf area (oxygen saturation of 1.7-2.9%) appeared to show too low oxygen levels for spawning to take place. Hence, significant parts of this large shelf area appear unsuited for successful reproduction of the bearded goby, in particular for nest building by the territorials.

  7. Size Dependent Male Reproductive Tactic in the Two-Spotted Goby (Gobiusculus flavescens).

    Science.gov (United States)

    Utne-Palm, A C; Eduard, K; Jensen, K H; Mayer, I; Jakobsen, P J

    2015-01-01

    Male investment in testes and sperm duct gland in the polygamous nest breeding two-spotted goby Gobiusculus flavescens (Fabricius) was investigated in relation to time in reproductive season and individual physical parameters. This small teleost fish is most likely the most abundant species found along the rocky shores of the North East Atlantic. The two-spotted goby has a single reproductive season, during which nest-caring males can raise several clutches of offspring. According to the literature the males are on average larger than the females. Here we report for the first time a population showing a reversal of this trend, with males on average being smaller than females, a difference likely caused by a large proportion of small males. Early in the breeding season these small males have typical sneaker characters, with relatively large testes and small seminal duct glands compared to the larger dominant territorial males. The presence of these two alternative male reproductive tactics is confirmed by histological studies, which shows the presence of sperm in the sperm duct glands (SDG) of smaller males, but not in the SDG of intermediate and larger males. To our knowledge, males with typical sneaker characters have not been reported in earlier studied populations of two-spotted goby. Interestingly we found that testes investment declined significantly over the course of the breeding season, and that this reduction was significantly more pronounced in small compared to the large males. Further, a significant increase in seminal duct gland (SDG) mass was observed for the smaller males over the breeding season. We propose that this indicates a possible shift in mating tactic by smaller males from a parasitic to a nest-holding tactic over the course of the breeding season. Thus, the observed size dependent plasticity in investment in SDG over time suggests that the reproductive tactic of G. flavescens is conditional, and possibly influenced by mate availability and

  8. Size Dependent Male Reproductive Tactic in the Two-Spotted Goby (Gobiusculus flavescens.

    Directory of Open Access Journals (Sweden)

    A C Utne-Palm

    Full Text Available Male investment in testes and sperm duct gland in the polygamous nest breeding two-spotted goby Gobiusculus flavescens (Fabricius was investigated in relation to time in reproductive season and individual physical parameters. This small teleost fish is most likely the most abundant species found along the rocky shores of the North East Atlantic. The two-spotted goby has a single reproductive season, during which nest-caring males can raise several clutches of offspring. According to the literature the males are on average larger than the females. Here we report for the first time a population showing a reversal of this trend, with males on average being smaller than females, a difference likely caused by a large proportion of small males. Early in the breeding season these small males have typical sneaker characters, with relatively large testes and small seminal duct glands compared to the larger dominant territorial males. The presence of these two alternative male reproductive tactics is confirmed by histological studies, which shows the presence of sperm in the sperm duct glands (SDG of smaller males, but not in the SDG of intermediate and larger males. To our knowledge, males with typical sneaker characters have not been reported in earlier studied populations of two-spotted goby. Interestingly we found that testes investment declined significantly over the course of the breeding season, and that this reduction was significantly more pronounced in small compared to the large males. Further, a significant increase in seminal duct gland (SDG mass was observed for the smaller males over the breeding season. We propose that this indicates a possible shift in mating tactic by smaller males from a parasitic to a nest-holding tactic over the course of the breeding season. Thus, the observed size dependent plasticity in investment in SDG over time suggests that the reproductive tactic of G. flavescens is conditional, and possibly influenced by mate

  9. Evidence for ontogenetically and morphologically distinct alternative reproductive tactics in the invasive Round Goby Neogobius melanostomus.

    Directory of Open Access Journals (Sweden)

    Katinka Bleeker

    Full Text Available Alternative reproductive tactics are characterized by the occurrence of discrete alternative morphs that differ in behavioural, morphological and physiological traits within the same sex. Although much effort has been made to describe the behaviour, morphology and physiology of such alternative morphs, less effort has been invested investigating how much overlap there is in the characteristics of such morphs in natural populations. We studied random population samples of the invasive Round Goby Neogobius melanostomus from five different localities in the river Rhine system in the Netherlands. We found two morphologically and physiologically distinct male morphs which likely represent alternative reproductive tactics. Almost all mature males under 9.35 cm total length had a gonadosomatic index > 3%, suggestive of a sneaker tactic, while nearly all males above 9.35 cm has a gonadosomatic index of < 3%, suggestive of a parental tactic. Cheek size and eye diameter alone were sufficient to distinguish the two morphs. Gonads had a different relationship with size in the two morphs, indicating separate growth trajectories. The gonad mass of sneaker morphs would be ca. 7.5 times as high as the gonad mass of parental morphs of the same total length after extrapolation. Few (9% intermediates were found, suggesting that the expression of alternative reproductive tactics is determined before the first breeding season. This contrasts with studies on other goby species, which show evidence of plastic tactics that can be affected by social circumstances. We conclude that it is possible to distinguish two alternative male morphs in the Dutch Round Goby population using morphological measurements alone. Although behavioural observations are needed to provide conclusive evidence, the difference in GSI between these morphs indicates that these morphs reflect alternative reproductive tactics.

  10. The fine structure of the sperm of the round goby (Neogobius melanostomus)

    Science.gov (United States)

    Allen, Jeffrey D.; Walker, Glenn K.; Nichols, Susan J.; Sorenson, Dorothy

    2004-01-01

    The fine structural details of the spermatozoon of the round goby are presented for the first time in this study. Scanning and transmission electron microscopic examination of testis reveals an anacrosomal spermatozoon with a slightly elongate head and uniformly compacted chromatin. The midpiece contains a single, spherical mitochondrion. Two perpendicularly oriented centrioles lie in a deep, eccentric nuclear fossa with no regularly observed connection to the nucleus. The flagellum develops bilateral fins soon after emerging from the fossa; each extends approximately 1 A?m from the axoneme and persists nearly the length of the flagellum.

  11. Ejaculate of sneaker males is pheromonally inconspicuous in the black goby, Gobius niger (Teleostei, Gobiidae).

    Science.gov (United States)

    Locatello, L; Mazzoldi, C; Rasotto, M B

    2002-11-01

    The black goby, Gobius niger, shows alternative male mating tactics, i.e., parental and sneaker males. Males release a sexual pheromone that attracts females and stimulates aggressive displays in males. This pheromone is produced by the mesorchial gland, a structure well developed in parental males but markedly undeveloped in sneakers. We measured the behavioral response of parental males to the ejaculates of males performing different reproductive tactics. Parental males reacted to the ejaculate of other parental males, with stereotypic aggressive behaviors, but not to the ejaculate of sneakers; consequently sneaker male ejaculate appears to be pheromonally inconspicuous. Copyright 2002 Wiley-Liss, Inc.

  12. Chaque goutte compte – entrevue de Gabin Koto N'Gobi, boursier ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    11 mai 2012 ... C'est la pénurie d'eau dans la région semi-aride dans le nord de son pays natal, le Bénin, qui est sa véritable motivation. ... M. Koto N'Gobi admet : « Au début, je n'étais pas tellement intéressé, puis je me suis rendu compte qu'une recherche sur cette question cadrait parfaitement avec ma formation en ...

  13. 基于决策树的戈壁信息提取研究%Gobi information extraction based on decision tree classification method

    Institute of Scientific and Technical Information of China (English)

    冯益明; 智长贵; 姚爱冬

    2013-01-01

    Gobi is one of the main landscape types of earth' s surface in the arid region of northwestern parts of China, with the total area of 458 000-757 000 km2, accounting for the 4.8%-7.9% of China's total land area. The gobi holds abundant natural resources such as minerals, wind energy and solar power. Meanwhile, many modern cities and towns and some important traffic routes were also constructed on the gobi region. The gobi region plays an important role in the construction of western economy. Therefore, it is important to launch the gobi research under current social and economic conditions, and accurately revealing the distribution and area of gobi is the base and premise of launching the gobi research. At present, it is difficult to do fieldwork due to the execrable natural conditions and the sparse dweller in the gobi region, which leads to the scarcity of research documents on the situation, distribution, type classification, transformation and utilization of gobi. The studied region of this paper is a typical gobi distribution region, locating in Ejina County in Inner Mongolia, China, and its climatic characteristics include lack of rain, more evaporation, full sunshine, large temperature difference and frequent windy sand weather. Using Remote Sensing imageries Landsat TM5 and TM7 of plant growth season of 2005-2010, the DEM with 30 m spatial resolution, administrative map, present land use map, field investigation data and related documents as the basic data resource. Firstly, the non-gobi distribution regions were extracted in GIS software by analyzing DEM. Then, based on the analysis of spectral characteristics of difference typical ground objects, the information extraction model of Decision Tree based on knowledge was constructed to classify the remote sensing imageries, and eroded gobi and cumulated gobi were relatively accurately separated. The general accuracy of the extracted gobi information reached 91.57%. There were few materials in China on using

  14. Effects of benzo(a)pyrene on the skeletal development of Sebastiscus marmoratus embryos and the molecular mechanism involved

    International Nuclear Information System (INIS)

    He Chengyong; Zuo Zhenghong; Shi Xiao; Li Ruixia; Chen Donglei; Huang Xin; Chen Yixin; Wang Chonggang

    2011-01-01

    Polycyclic aromatic hydrocarbons (PAHs) are widespread environmental contaminants, which have been known to be carcinogenic and teratogenic. However, the skeletal development toxicity of PAHs and the mechanism involved remain unclear. In fishes, the neurocranial and craniofacial skeleton develop as cartilage. The signaling molecules of hedgehog (Hh) family play crucial roles in regulating skeletal development. In the present study, rockfish (Sebastiscus marmoratus) embryos were exposed to benzo(a)pyrene (BaP) for 7 days at environmental levels (0.05, 0.5 and 5 nmol/L) which resulted in craniofacial skeleton deformities. BaP exposure reduced the cell proliferation activity in the craniofacial skeleton as detected by quantitative PCR and in situ hybridization. The expression of Sonic hedgehog (Shh), rather than Indian hedgehog (Ihh), was down-regulated in the craniofacial skeleton in the 0.5 and 5 nmol/L groups. Consistent with the Shh results, the expression of Ptch1 and Gli2 was decreased by BaP exposure and BMP4 was presented on changes in the 0.5 and 5 nmol/L groups. These results suggested that BaP could impair the expression and function of Shh signaling pathway, perturbing the proliferation of chondrocytes and so disturbing craniofacial skeletal development.

  15. Hypercapnia and low pH induce neuroepithelial cell proliferation and emersion behaviour in the amphibious fish Kryptolebias marmoratus.

    Science.gov (United States)

    Robertson, Cayleih E; Turko, Andy J; Jonz, Michael G; Wright, Patricia A

    2015-10-01

    Aquatic hypercapnia may have helped to drive ancestral vertebrate invasion of land. We tested the hypothesis that amphibious fishes sense and respond to elevated aquatic PCO2 by behavioural avoidance mechanisms, and by morphological changes at the chemoreceptor level. Mangrove rivulus (Kryptolebias marmoratus) were exposed to 1 week of normocapnic control water (pH 8), air, hypercapnia (5% CO2, pH 6.8) or isocapnic acidosis (pH 6.8). We found that the density of CO2/H(+) chemoreceptive neuroepithelial cells (NECs) was increased in hypercapnia or isocapnic acidosis-exposed fish. Projection area (a measure of cell size) was unchanged. Acute exposure to progressive hypercapnia induced the fish to emerse (leave water) at water pH values ∼6.1, whereas addition of HCl to water caused a more variable response with a lower pH threshold (∼pH 5.5). These results support our hypothesis and suggest that aquatic hypercapnia provides an adequate stimulus for extant amphibious fishes to temporarily transition from aquatic to terrestrial habitats. © 2015. Published by The Company of Biologists Ltd.

  16. Effects of X-irradiation and thymectomy on the immune response of the marine teleost, Sebastiscus marmoratus

    International Nuclear Information System (INIS)

    Nakanishi, T.

    1986-01-01

    Effects of X-irradiation and thymectomy on the immune response of the rock fish, S. marmoratus were studied. Animals were thymectomized and irradiated at the dose of 2000 R. In non-thymectomized and irradiated fish, injected with SRBC one week after irradiation, antibody production was completely suppressed and they required twice the time for rejection of scales allografted three days after irradiation. On the other hand, fish which were irradiated four days after thymectomy and injected one week after irradiation, showed a fairly high level of antibody, although, in the allograft rejection, no significant difference was observed when compared to the irradiated fish. Furthermore, animals thymectomized, irradiated and autoimplanted showed higher production of antibody when immunized three months after irradiation compared to matched controls. In the same manner, in the allograft rejection, a slight restoration was found in fish reconstituted with a non-irradiated thymus. From these results, it is considered that, as in mammals, the adult thymus of fish plays an important role in recovery from the damage to the immune system caused by irradiation. Furthermore, a combination of X-irradiation and thymectomy suggests that suppressor T-cells which are resistant to X-rays exist in the fish thymus

  17. Place learning prior to and after telencephalon ablation in bamboo and coral cat sharks (Chiloscyllium griseum and Atelomycterus marmoratus).

    Science.gov (United States)

    Fuss, Theodora; Bleckmann, Horst; Schluessel, Vera

    2014-01-01

    This study assessed complex spatial learning and memory in two species of shark, the grey bamboo shark (Chiloscyllium griseum) and the coral cat shark (Atelomycterus marmoratus). It was hypothesized that sharks can learn and apply an allocentric orientation strategy. Eight out of ten sharks successfully completed the initial training phase (by locating a fixed goal position in a diamond maze from two possible start points) within 14.9 ± 7.6 sessions and proceeded to seven sets of transfer tests, in which sharks had to perform under altered environmental conditions. Transfer tests revealed that sharks had oriented and solved the tasks visually, using all of the provided environmental cues. Unintentional cueing did not occur. Results correspond to earlier studies on spatial memory and cognitive mapping in other vertebrates. Future experiments should investigate whether sharks possess a cognitive spatial mapping system as has already been found in several teleosts and stingrays. Following the completion of transfer tests, sharks were subjected to ablation of most of the pallium, which compromised their previously acquired place learning abilities. These results indicate that the telencephalon plays a crucial role in the processing of information on place learning and allocentric orientation strategies.

  18. Effects of benzo(a)pyrene on the skeletal development of Sebastiscus marmoratus embryos and the molecular mechanism involved

    Energy Technology Data Exchange (ETDEWEB)

    He Chengyong [Key Laboratory of Ministry of Education for Subtropical Wetland Ecosystem Research, School of Life Sciences, Xiamen University, Xiamen (China); Zuo Zhenghong [Key Laboratory of Ministry of Education for Subtropical Wetland Ecosystem Research, School of Life Sciences, Xiamen University, Xiamen (China); State Key Laboratory of Marine Environmental Science, Xiamen University, Xiamen (China); Shi Xiao; Li Ruixia; Chen Donglei; Huang Xin; Chen Yixin [Key Laboratory of Ministry of Education for Subtropical Wetland Ecosystem Research, School of Life Sciences, Xiamen University, Xiamen (China); Wang Chonggang, E-mail: cgwang@xmu.edu.cn [Key Laboratory of Ministry of Education for Subtropical Wetland Ecosystem Research, School of Life Sciences, Xiamen University, Xiamen (China); State Key Laboratory of Marine Environmental Science, Xiamen University, Xiamen (China)

    2011-01-25

    Polycyclic aromatic hydrocarbons (PAHs) are widespread environmental contaminants, which have been known to be carcinogenic and teratogenic. However, the skeletal development toxicity of PAHs and the mechanism involved remain unclear. In fishes, the neurocranial and craniofacial skeleton develop as cartilage. The signaling molecules of hedgehog (Hh) family play crucial roles in regulating skeletal development. In the present study, rockfish (Sebastiscus marmoratus) embryos were exposed to benzo(a)pyrene (BaP) for 7 days at environmental levels (0.05, 0.5 and 5 nmol/L) which resulted in craniofacial skeleton deformities. BaP exposure reduced the cell proliferation activity in the craniofacial skeleton as detected by quantitative PCR and in situ hybridization. The expression of Sonic hedgehog (Shh), rather than Indian hedgehog (Ihh), was down-regulated in the craniofacial skeleton in the 0.5 and 5 nmol/L groups. Consistent with the Shh results, the expression of Ptch1 and Gli2 was decreased by BaP exposure and BMP4 was presented on changes in the 0.5 and 5 nmol/L groups. These results suggested that BaP could impair the expression and function of Shh signaling pathway, perturbing the proliferation of chondrocytes and so disturbing craniofacial skeletal development.

  19. Exploring the Utility of Partial Cytochrome c Oxidase Subunit 1 for DNA Barcoding of Gobies

    Directory of Open Access Journals (Sweden)

    Hyung-Bae Jeon

    2012-10-01

    Full Text Available Gobiids are hyperdiverse compared with other teleost groups, with about 2,000 species occurring in marine, freshwater, and blackish habitats, and they show a remarkable variety of morphologies and ecology. Testing the effectiveness of DNA barcodes on species that have emerged as a result of radiation remains a major challenge in evolutionary biology. Here, we used the cytochrome c oxidase subunit 1 (COI sequences from 144 species of gobies and related species to evaluate the performance of distance-based DNA barcoding and to conduct a phylogenetic analysis. The average intra-genus genetic distance was considerably higher than that obtained in previous studies. Additionally, the interspecific divergence at higher taxonomic levels was not significantly different from that at the intragenus level, suggesting that congeneric gobies possess substantial interspecific sequence divergence in their COI gene. However, levels of intragenus divergence varied greatly among genera, and we do not provide sufficient evidence for using COI for cryptic species delimitation. Significantly more nucleotide changes were observed at the third codon position than that at the first and the second codons, revealing that extensive variation in COI reflects synonymous changes and little protein level variation. Despite clear signatures in several genera, the COI sequences did resolve genealogical relationships in the phylogenetic analysis well. Our results support the validity of COI barcoding for gobiid species identification, but the utilization of more gene regions will assist to offer a more robust gobiid species phylogeny.

  20. Cleaning interactions by gobies on a tropical eastern Pacific coral reef.

    Science.gov (United States)

    Quimbayo, J P; Zapata, F A

    2018-04-01

    The present study describes the cleaning interactions among species of cleaner gobies Tigrigobius spp. and Elacatinus puncticulatus (family Gobiidae) and the client fish species they clean in a coral reef of Gorgona Island, Colombia. In 419 cleaning events, we observed 27 species acting as clients of Tigrigobius spp., whereas only nine were clients of E. puncticulatus. Paranthias colonus and Cephalopholis panamensis were the species most commonly cleaned by Tigrigobius spp., while Ophioblennius steindachneri and Stegastes acalpulcoensis were the clients most commonly cleaned by E. puncticulatus. The abundance (but not the body size) of clients was an important variable predicting the cleaning frequency observed for clients of Tigrigobius spp., but this was not the case for clients of E. puncticulatus. Additionally, Tigrigobius spp. preferred cleaning planktivores, sessile invertebrate feeders and territorial herbivores (Ivlev's index >0·15), whereas E. puncticulatus did not exhibit any preference. We observed two major peaks of cleaning activity for Tigrigobius spp., one in the early morning and another one in the late afternoon. These results suggest that Tigrigobius spp. is a specialized cleaner goby, whereas E. puncticulatus is a facultative cleaner that cleans sporadically. © 2018 The Fisheries Society of the British Isles.

  1. Face your fears: cleaning gobies inspect predators despite being stressed by them.

    Directory of Open Access Journals (Sweden)

    Marta C Soares

    Full Text Available social stressors typically elicit two distinct behavioural responses in vertebrates: an active response (i.e., "fight or flight" or behavioural inhibition (i.e., freezing. Here, we report an interesting exception to this dichotomy in a Caribbean cleaner fish, which interacts with a wide variety of reef fish clients, including predatory species. Cleaning gobies appraise predatory clients as potential threat and become stressed in their presence, as evidenced by their higher cortisol levels when exposed to predatory rather than to non-predatory clients. Nevertheless, cleaning gobies neither flee nor freeze in response to dangerous clients but instead approach predators faster (both in captivity and in the wild, and interact longer with these clients than with non-predatory clients (in the wild. We hypothesise that cleaners interrupt the potentially harmful physiological consequences elicited by predatory clients by becoming increasingly proactive and by reducing the time elapsed between client approach and the start of the interaction process. The activation of a stress response may therefore also be responsible for the longer cleaning service provided by these cleaners to predatory clients in the wild. Future experimental studies may reveal similar patterns in other social vertebrate species when, for instance, individuals approach an opponent for reconciliation after a conflict.

  2. Body size correlates with fertilization success but not gonad size in grass goby territorial males.

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    Jose Martin Pujolar

    Full Text Available In fish species with alternative male mating tactics, sperm competition typically occurs when small males that are unsuccessful in direct contests steal fertilization opportunities from large dominant males. In the grass goby Zosterisessor ophiocephalus, large territorial males defend and court females from nest sites, while small sneaker males obtain matings by sneaking into nests. Parentage assignment of 688 eggs from 8 different nests sampled in the 2003-2004 breeding season revealed a high level of sperm competition. Fertilization success of territorial males was very high but in all nests sneakers also contributed to the progeny. In territorial males, fertilization success correlated positively with male body size. Gonadal investment was explored in a sample of 126 grass gobies collected during the period 1995-1996 in the same area (61 territorial males and 65 sneakers. Correlation between body weight and testis weight was positive and significant for sneaker males, while correlation was virtually equal to zero in territorial males. That body size in territorial males is correlated with fertilization success but not gonad size suggests that males allocate much more energy into growth and relatively little into sperm production once the needed size to become territorial is attained. The increased paternity of larger territorial males might be due to a more effective defense of the nest in comparison with smaller territorial males.

  3. Body size correlates with fertilization success but not gonad size in grass goby territorial males.

    Science.gov (United States)

    Pujolar, Jose Martin; Locatello, Lisa; Zane, Lorenzo; Mazzoldi, Carlotta

    2012-01-01

    In fish species with alternative male mating tactics, sperm competition typically occurs when small males that are unsuccessful in direct contests steal fertilization opportunities from large dominant males. In the grass goby Zosterisessor ophiocephalus, large territorial males defend and court females from nest sites, while small sneaker males obtain matings by sneaking into nests. Parentage assignment of 688 eggs from 8 different nests sampled in the 2003-2004 breeding season revealed a high level of sperm competition. Fertilization success of territorial males was very high but in all nests sneakers also contributed to the progeny. In territorial males, fertilization success correlated positively with male body size. Gonadal investment was explored in a sample of 126 grass gobies collected during the period 1995-1996 in the same area (61 territorial males and 65 sneakers). Correlation between body weight and testis weight was positive and significant for sneaker males, while correlation was virtually equal to zero in territorial males. That body size in territorial males is correlated with fertilization success but not gonad size suggests that males allocate much more energy into growth and relatively little into sperm production once the needed size to become territorial is attained. The increased paternity of larger territorial males might be due to a more effective defense of the nest in comparison with smaller territorial males.

  4. Extirpation and recolonization in a metapopulation of an endangered fish, the tidewater goby

    Science.gov (United States)

    Lafferty, K.D.; Swift, C.C.; Ambrose, R.F.

    1999-01-01

    The tidewater goby (Eucyclogobius newberryi), an endangered species in the United States, occurs in a series of isolated coastal wetlands in California. Using historical presence-absence data and our own surveys, we estimated annual rates of extirpation and recolonization for several populations of the goby in southern California. As predicted, large wetlands had lower rates of extirpation than small wetlands. There was a negative but statistically nonsignificant correlation between recolonization rate and distance to the nearest northerly source population. Populations at small sites were sensitive to drought, presumably because droughts can eliminate suitable habitat at small wetlands. Populations in small wetlands have declined over time, even after accounting for variation in stream flow, supporting the species' endangered status. Our study emphasizes the need to understand metapopulation dynamics for conserving species where the unit of conservation is a local population. It is also emphasizes the importance of not treating metapopulations as identical units. Finally, our results provide a means for describing the decline of a species that is complex in time and space and provide insight into how to target protection measures among metapopulations.

  5. Biology of the Sanzo's goby, Lesueurigobius sanzoi (de Buen, 1918, off Cabo Raso, Portugal

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    Cristina Paulo Martins

    2004-06-01

    Full Text Available The presence of Sanzos's goby, Lesueurigobius sanzoi (de Buen, 1918, off Cabo Raso, Portugal, is recorded for the first time. The biology of this population was studied using 11 samples collected between April 2000 and September 2001 at depths of 70-100 m on muddy and sandy bottoms. The females reach a standard length of 110 mm and the males 103 mm. It attains an age of 24 months, which equals two breeding seasons. The otoliths form two translucent rings each year, which corresponds to the winter growth and the reproduction period. Sanzo's gobies can be classified as prematur and standard individuals, according to whether the first breeding occurs before or after the first winter respectively. Standard individuals, which have an extended first growth, reach a longer length than prematur individuals, whose first growth is much shorter. Although discrete, sexual dimorphism was noticeable even outside the spawning season. The breeding season occurs between May and September/October with more than one spawning. The minimum length for which the maturity stage occurs is 64 mm, at an age of 0+. The feeding activity is quite constant throughout the year, and the diet consists predominantly of small crustacea and molluscs, although polychaets also feature commonly in its diet.

  6. Flowing water affects fish fast-starts: escape performance of the Hawaiian stream goby, Sicyopterus stimpsoni.

    Science.gov (United States)

    Diamond, Kelly M; Schoenfuss, Heiko L; Walker, Jeffrey A; Blob, Richard W

    2016-10-01

    Experimental measurements of escape performance in fishes have typically been conducted in still water; however, many fishes inhabit environments with flow that could impact escape behavior. We examined the influences of flow and predator attack direction on the escape behavior of fish, using juveniles of the amphidromous Hawaiian goby Sicyopterus stimpsoni In nature, these fish must escape ambush predation while moving through streams with high-velocity flow. We measured the escape performance of juvenile gobies while exposing them to a range of water velocities encountered in natural streams and stimulating fish from three different directions. Frequency of response across treatments indicated strong effects of flow conditions and attack direction. Juvenile S. stimpsoni had uniformly high response rates for attacks from a caudal direction (opposite flow); however, response rates for attacks from a cranial direction (matching flow) decreased dramatically as flow speed increased. Mechanical stimuli produced by predators attacking in the same direction as flow might be masked by the flow environment, impairing the ability of prey to detect attacks. Thus, the likelihood of successful escape performance in fishes can depend critically on environmental context. © 2016. Published by The Company of Biologists Ltd.

  7. Water and vapor transfer in vadose zone of Gobi desert and riparian in the hyper arid environment of Ejina, China

    Science.gov (United States)

    Du, C.; Yu, J.; Sun, F.; Liu, X.

    2015-12-01

    To reveal how water and vapor transfer in vadose zone affect evapotranspiration in Gobi desert and riparian in hyper arid region is important for understanding eco-hydrological process. Field studies and numerical simulations were imported to evaluate the water and vapor movement processes under non isothermal and lower water content conditions. The soil profiles (12 layers) in Gobi desert and riparian sites of Ejina were installed with sensors to monitor soil moisture and temperature for 1 year. The meteorological conditions and water table were measured by micro weather stations and mini-Divers respectively in the two sites. Soil properties, including particles composition, moisture, bulk density, water retention curve, and saturated hydraulic conductivity of two site soil profiles, was measured. The observations showed that soil temperatures for the two sites displayed large diurnal and seasonal fluctuations. Temperature gradients with depth resulted in a downward in summer and upward in winter and became driving force for thermal vapor movement. Soil moistures in Gobi desert site were very low and varied slowly with time. While the soil moistures in riparian site were complicated due to root distribution but water potentials remained uniform with time. The hydrus-1D was employed to simulate evapotranspiration processes. The simulation results showed the significant difference of evaporation rate in the Gobi desert and riparian sites.

  8. Response of benthic macroinvertebrate assemblages to round (Neogobius melanostomus, Pallas 1814) and tubenose (Proterorhinus semilunaris, Heckel 1837) goby predation pressure

    Czech Academy of Sciences Publication Activity Database

    Mikl, Libor; Adámek, Zdeněk; Všetičková, Lucie; Janáč, Michal; Roche, Kevin Francis; Šlapanský, Luděk; Jurajda, Pavel

    2017-01-01

    Roč. 785, č. 1 (2017), s. 219-232 ISSN 0018-8158 R&D Projects: GA ČR(CZ) GAP505/11/1768 Institutional support: RVO:68081766 Keywords : Invasive species * Gobies * Macroinvertebrates * Impact * European rivers * Diet Subject RIV: EH - Ecology, Behaviour OBOR OECD: Marine biology, freshwater biology, limnology Impact factor: 2.056, year: 2016

  9. Population and reproductive characteristics of a non-native western tubenose goby (Proterorhinus semilunaris) population unaffected by gobiid competitors

    Czech Academy of Sciences Publication Activity Database

    Valová, Zdenka; Konečná, Markéta; Janáč, Michal; Jurajda, Pavel

    2015-01-01

    Roč. 10, č. 1 (2015), s. 57-68 ISSN 1798-6540 R&D Projects: GA ČR(CZ) GAP505/11/1768 Institutional support: RVO:68081766 Keywords : Gobiidae * invasive species * non-indigenous * tubenose goby * population dynamics Subject RIV: EH - Ecology, Behaviour Impact factor: 1.955, year: 2015

  10. Population structure, condition, and reproduction characteristics of native monkey goby, Neogobius fluviatilis (Actinopterygii: Perciformes Gobiidae), in the Bulgarian Danube

    Czech Academy of Sciences Publication Activity Database

    Konečná, Markéta; Jurajda, Pavel

    2012-01-01

    Roč. 42, č. 4 (2012), s. 321-327 ISSN 0137-1592 R&D Projects: GA ČR(CZ) GAP505/11/1768 Institutional support: RVO:68081766 Keywords : monkey goby * invasion * Bulgaria * Danube, condition * GSI * ovary structure Subject RIV: EH - Ecology, Behaviour Impact factor: 0.606, year: 2012

  11. Historical considerations and comments on the type series of Cyrtodactylus marmoratus Gray, 1831, with an updated comparative table for the bent-toed geckos of the Sunda Islands and Sulawesi.

    Science.gov (United States)

    Mecke, Sven; Kieckbusch, Max; Hartmann, Lukas; Kaiser, Hinrich

    2016-10-17

    Cyrtodactylus marmoratus Gray, 1831, a species of bent-toed gecko exhibiting a precloacal groove in males, was described on the basis of specimens collected by Heinrich Kuhl and Johan Conrad van Hasselt in Java, Greater Sunda Islands, Indonesia. Kluge (1985) subsequently designated a lectotype for C. marmoratus from a series of these specimens (i.e., syntypes), now housed in the herpetological collection at Naturalis (formerly the Rijksmuseum van Natuurlijke Historie; RMNH), Leiden, the Netherlands. Our work at Naturalis shows that the type series of C. marmoratus at RMNH actually comprises two sets of specimens, and that examination of specimens from one set or the other by different authors, including Kluge (1985), is responsible for some confusion surrounding the type series of this species. As a consequence, we present relevant morphological data for all 14 specimens constituting the type series of C. marmoratus at RMNH for the first time. The type status of two specimens of C. marmoratus in the collection at the Muséum National d'Histoire Naturelle, Paris, France, remains unresolved at present. Owing to the inconsistent naming and application of terms for some key characters (e.g., groove, sulcus, pit, hollow, depression) used in the diagnoses of Cyrtodactylus species, we here propose a set of novel and useful definitions that are supported by photographs. We also illustrate the sexually dimorphic expression of this character in C. marmoratus. Finally, we present a revised comparative table for the bent-toad geckos of the Sunda Islands and Sulawesi.

  12. Zebra mussel beds: an effective feeding ground for Ponto-Caspian gobies or suitable shelter for their prey?

    Science.gov (United States)

    Kobak, Jarosław; Poznańska, Małgorzata; Jermacz, Łukasz; Kakareko, Tomasz; Prądzynski, Daniel; Łodygowska, Małgorzata; Montowska, Karolina; Bącela-Spychalska, Karolina

    2016-01-01

    Aggregations of the Ponto-Caspian invasive zebra mussel ( Dreissena polymorpha ) constitute a suitable habitat for macroinvertebrates, considerably increasing their abundance and providing effective antipredator protection. Thus, the overall effect of a mussel bed on particular predator species may vary from positive to negative, depending on both prey density increase and predator ability to prey in a structurally complex habitat. Alien Ponto-Caspian goby fish are likely to be facilitated when introduced into new areas by zebra mussels, provided that they are capable of utilizing mussel beds as habitat and feeding grounds. We ran laboratory experiments to find which prey (chironomid larvae) densities (from ca. 500 to 2,000 individuals m -2 ) in a mussel bed make it a more beneficial feeding ground for the racer goby Babka gymnotrachelus (RG) and western tubenose goby Proterorhinus semilunaris (WTG) compared to sandy and stone substrata (containing the basic prey density of 500 ind. m -2 ). Moreover, we checked how food availability affects habitat selection by fish. Mussel beds became more suitable for fish than alternative mineral substrata when food abundance was at least two times higher (1,000 vs. 500 ind. m -2 ), regardless of fish size and species. WTG was associated with mussel beds regardless of its size and prey density, whereas RG switched to this habitat when it became a better feeding ground than alternative substrata. Larger RG exhibited a stronger affinity for mussels than small individuals. WTG fed more efficiently from a mussel bed at high food abundances than RG. A literature review has shown that increasing chironomid density, which in our study was sufficient to make a mussel habitat an attractive feeding ground for the gobies, is commonly observed in mussel beds in the field. Therefore, we conclude that zebra mussels may positively affect the alien goby species and are likely to facilitate their establishment in novel areas, contributing to an

  13. Zebra mussel beds: an effective feeding ground for Ponto-Caspian gobies or suitable shelter for their prey?

    Directory of Open Access Journals (Sweden)

    Jarosław Kobak

    2016-11-01

    Full Text Available Aggregations of the Ponto-Caspian invasive zebra mussel (Dreissena polymorpha constitute a suitable habitat for macroinvertebrates, considerably increasing their abundance and providing effective antipredator protection. Thus, the overall effect of a mussel bed on particular predator species may vary from positive to negative, depending on both prey density increase and predator ability to prey in a structurally complex habitat. Alien Ponto-Caspian goby fish are likely to be facilitated when introduced into new areas by zebra mussels, provided that they are capable of utilizing mussel beds as habitat and feeding grounds. We ran laboratory experiments to find which prey (chironomid larvae densities (from ca. 500 to 2,000 individuals m−2 in a mussel bed make it a more beneficial feeding ground for the racer goby Babka gymnotrachelus (RG and western tubenose goby Proterorhinus semilunaris (WTG compared to sandy and stone substrata (containing the basic prey density of 500 ind. m−2. Moreover, we checked how food availability affects habitat selection by fish. Mussel beds became more suitable for fish than alternative mineral substrata when food abundance was at least two times higher (1,000 vs. 500 ind. m−2, regardless of fish size and species. WTG was associated with mussel beds regardless of its size and prey density, whereas RG switched to this habitat when it became a better feeding ground than alternative substrata. Larger RG exhibited a stronger affinity for mussels than small individuals. WTG fed more efficiently from a mussel bed at high food abundances than RG. A literature review has shown that increasing chironomid density, which in our study was sufficient to make a mussel habitat an attractive feeding ground for the gobies, is commonly observed in mussel beds in the field. Therefore, we conclude that zebra mussels may positively affect the alien goby species and are likely to facilitate their establishment in novel areas

  14. Use of eugenol in Jundiá da Amazônia (Leiarius marmoratus: effects on sedation and evaluation hemogasometry

    Directory of Open Access Journals (Sweden)

    Claucia Aparecida Honorato

    2014-10-01

    Full Text Available This work aims to evaluate the use of eugenol as an anesthetic for jundiá da Amazônia (Leiarius marmoratus, measuring the time to anesthesia induction in different concentrações and their effects in gas exchange. The results were analyzed according to a completely randomized design (DIC with eight treatments (control, 10, 20, 40, 80, 120, 150, 200 mg L-1 of eugenol and ten repetitions. Time values of anesthetic induction and recovery, according to the level of eugenol underwent polynomial regression (p<0.05. The analysis of variance (ANOVA and averages were compared by Tukey test. Were determined the time of anesthesia and recovery. The parameters were analyzed blood glucose, pH, partial pressure of oxygen (PaO2, partial pressure of carbon dioxide (PaCO2, concentration of bicarbonate (HCO-3, sodium (Na, potassium (K, calcium (Ca and chloride (Cl. The concentrations of 40 and 80 mg.L-1 of eugenol were the ones who presented time deep anesthesia induction of 59.5 ± 17.5 sec. and 58.4 ± 18.6 sec. respectively. The concentrations above 120 mg. L-¹ presented mortality. These fish subjected to different level of eugenol did not show changes in blood oxygen pressure (PaO2 and carbon dioxide (PaCO2. The fish when subjected to concentrations above 80 mg L-1 showed an increase of bicarbonate. The plasma glucose values showed significant elevation in response to the bath with anesthetic eugenol. The concentrations of sodium, chloride, potassium and plasma protein remained constants indicating that the process of anesthesia was not long lasting enough to induce changes in the electrolyte balance. Within the conditions of this study, it can be concluded that eugenol is a suitable anesthetic for the silver. This product may be used at a concentration of 40 mg. L-1 without causing changes hemogasométrica.

  15. Cutaneous vasoregulation during short- and long-term aerial acclimation in the amphibious mangrove rivulus, Kryptolebias marmoratus.

    Science.gov (United States)

    Cooper, C A; Litwiller, S L; Murrant, C L; Wright, P A

    2012-03-01

    The mangrove rivulus (Kryptolebias marmoratus) is an amphibious fish and evidence suggests that the cutaneous surface is the primary site of gas exchange during emersion. The aim of this study was to determine whether cutaneous blood vessels were regulated in the caudal fin during the initial transition from water to aerial exposure, and after 10 days of aerial acclimation. Acute changes (first 3 min following emersion) in the cutaneous vessels diameter were measured in real-time on live fish using light microscopy. The data show that under control conditions, only arterioles in the caudal fin were vasoactive. During the first 20s of aerial acclimation the arterioles significantly constricted (-2.1 ± 0.4 μm), which was followed immediately by a relaxation (from 40 to 180 s). This vasoconstriction was eliminated with the addition of phentolamine (50 μmoll(-1)), which indicates that the vasoconstriction was mediated by α-adrenoreceptors. Longer-term changes in the cutaneous surface vasculature were determined using fluorescent immunohistochemistry and antibodies for the endothelial marker, CD31. Fish aerially acclimated for 10 days exhibited significantly higher levels of endothelial fluorescence in the caudal fin when compared to control fish in water, indicating endothelial cell production (i.e. angiogenesis). These data combined show that for every emersion episode, there is an initial α-adrenergic mediated vasoconstriction, which is most likely, a stress response. This is then followed by a long-term acclimation involving an upregulation in endothelial cell production, which would subsequently enhance blood perfusion to the cutaneous surface and potentially increase the capacity for gas exchange with the external environment. Copyright © 2011 Elsevier Inc. All rights reserved.

  16. The amphibious fish Kryptolebias marmoratus uses different strategies to maintain oxygen delivery during aquatic hypoxia and air exposure.

    Science.gov (United States)

    Turko, Andy J; Robertson, Cayleih E; Bianchini, Kristin; Freeman, Megan; Wright, Patricia A

    2014-11-15

    Despite the abundance of oxygen in atmospheric air relative to water, the initial loss of respiratory surface area and accumulation of carbon dioxide in the blood of amphibious fishes during emersion may result in hypoxemia. Given that the ability to respond to low oxygen conditions predates the vertebrate invasion of land, we hypothesized that amphibious fishes maintain O2 uptake and transport while emersed by mounting a co-opted hypoxia response. We acclimated the amphibious fish Kryptolebias marmoratus, which are able to remain active for weeks in both air and water, for 7 days to normoxic brackish water (15‰, ~21kPa O2; control), aquatic hypoxia (~3.6kPa), normoxic air (~21 kPa) or aerial hypoxia (~13.6kPa). Angiogenesis in the skin and bucco-opercular chamber was pronounced in air- versus water-acclimated fish, but not in response to hypoxia. Aquatic hypoxia increased the O2-carrying capacity of blood via a large (40%) increase in red blood cell density and a small increase in the affinity of hemoglobin for O2 (P50 decreased 11%). In contrast, air exposure increased the hemoglobin O2 affinity (decreased P50) by 25% without affecting the number of red blood cells. Acclimation to aerial hypoxia both increased the O2-carrying capacity and decreased the hemoglobin O2 affinity. These results suggest that O2 transport is regulated both by O2 availability and also, independently, by air exposure. The ability of the hematological system to respond to air exposure independent of O2 availability may allow extant amphibious fishes, and may also have allowed primitive tetrapods to cope with the complex challenges of aerial respiration during the invasion of land. © 2014. Published by The Company of Biologists Ltd.

  17. Metabolic adjustments during semi-aestivation of the marble swamp eel (Synbranchus marmoratus, Bloch 1795 - a facultative air breathing fish Ajustes metabólicos do muçum (Synbranchus marmoratus, Bloch 1795 - um peixe de respiração aérea facultativa - durante semi-estivação

    Directory of Open Access Journals (Sweden)

    G. Moraes

    2005-05-01

    Full Text Available Metabolic changes, principally in intermediary metabolism and nitrogen excretion, were investigated in the marble swamp eel (Synbranchus marmoratus after 15 and 45 days of artificially induced semi-aestivation. Glucose, glycogen, lactate, pyruvate, free amino acids, triglycerides, ammonia, urea, and urate contents were determined in liver, kidney, white muscle, heart, brain, and plasma. Lactate dehydrogenase, glutamate dehydrogenase, malate dehydrogenase, aspartate amino transferase, alanine amino transferase, glutamine synthase, ornithine carbamoyl transferase, and arginase enzymes were assayed. The teleost S. marmoratus maintained initial energetic demands by lipid oxidation. The course of normal oxidative processes was observed through tissue enzyme profiles. After the lipid stores were exhausted, the fish consumed body proteins. Constant values of hematocrit during induced semi-aestivation suggested that the water balance remained normal. Therefore, the surrounding water was probably did not trigger the semi-aestivation in this teleost. Decrease of ammonia and increase of renal urea synthesis after 45 days of semi-aestivation led to the assumption that an alternative form of eliminating ammonia exists. Metabolic changes entailed by starvation were proposed to explain the biosynthesis of small molecules involved in the semi-aestivation of S. marmoratus.Foram investigadas variações metabólicas em muçum (Synbranchus marmoratus após 15 e 45 dias de semi-estivação artificial induzida, com ênfase no metabolismo intermediário e excreção de nitrogênio. Glicose, glicogênio, lactato, piruvato, aminoácidos livres, triglicerídios, amônia, uréia e uratos foram determinados em fígado, rim, músculo branco, coração, cérebro, e plasma. As enzimas lactato desidrogenase, glutamato desidrogenase, malato desidrogenase, aspartato amino transferase, alanina amino transferase, glutamina sintetase, ornitina carbamil transferase e arginase foram

  18. Spatial variation in background groundwater geochemistry of the Gurinai Wetland, Gobi Desert, Inner Mongolia

    Science.gov (United States)

    Gu, Weizu; Peters, N.E.

    1995-01-01

    Age dating of groundwater from several hand-dug wells in the Gurinai Wetland of the Badajilin-Gobi Desert, north-central China, indicated a continuum from present to 7625??155 years B.P. Water age correlates with concentration for some constituents. In general, concentrations of Fe, Cr, Se and Sr increase with increasing age, whereas Ca, Br, Zn and Rb decrease. Compared to concentration ranges reported for freshwaters, several constituents were much more concentrated including Na, Cl, Mg, Br and Th, and many others extended the upper concentration limit including Sr, Mo, Rb, Cr, U, Se, Nb and Ce. For Th, the maximum observed concentration extends the previously summarized maximum by more than an order of magnitude.

  19. Local adaptation despite high gene flow in the waterfall-climbing Hawaiian goby, Sicyopterus stimpsoni.

    Science.gov (United States)

    Moody, K N; Hunter, S N; Childress, M J; Blob, R W; Schoenfuss, H L; Blum, M J; Ptacek, M B

    2015-02-01

    Environmental heterogeneity can promote the emergence of locally adapted phenotypes among subpopulations of a species, whereas gene flow can result in phenotypic and genotypic homogenization. For organisms like amphidromous fishes that change habitats during their life history, the balance between selection and migration can shift through ontogeny, making the likelihood of local adaptation difficult to predict. In Hawaiian waterfall-climbing gobies, it has been hypothesized that larval mixing during oceanic dispersal counters local adaptation to contrasting topographic features of streams, like slope gradient, that can select for predator avoidance or climbing ability in juvenile recruits. To test this hypothesis, we used morphological traits and neutral genetic markers to compare phenotypic and genotypic distributions in recruiting juveniles and adult subpopulations of the waterfall-climbing amphidromous goby, Sicyopterus stimpsoni, from the islands of Hawai'i and Kaua'i. We found that body shape is significantly different between adult subpopulations from streams with contrasting slopes and that trait divergence in recruiting juveniles tracked stream topography more so than morphological measures of adult subpopulation differentiation. Although no evidence of population genetic differentiation was observed among adult subpopulations, we observed low but significant levels of spatially and temporally variable genetic differentiation among juvenile cohorts, which correlated with morphological divergence. Such a pattern of genetic differentiation is consistent with chaotic genetic patchiness arising from variable sources of recruits to different streams. Thus, at least in S. stimpsoni, the combination of variation in settlement cohorts in space and time coupled with strong postsettlement selection on juveniles as they migrate upstream to adult habitats provides the opportunity for morphological adaptation to local stream environments despite high gene flow. © 2014

  20. The use of rockfish Sebastiscus marmoratus as a sentinel species to assess petroleum hydrocarbons pollution: A case study in Quanzhou Bay, China.

    Science.gov (United States)

    Bo, Jun; Zheng, Ronghui; Kuang, Weiming; Hong, Fukun; Xie, Qing; Zhang, Yusheng

    2017-11-30

    To monitor the biological effects of marine pollution, choosing a native fish species and establishing suitable biomarkers are required. In this study, the full-length cDNA of cyp1a1 was cloned from Sebastiscus marmoratus (SM-CYP1A1). Then the dose-response and time-course induction of hepatic CYP1A1 mRNA by the crude oil water-soluble fraction (WSF) were determined. Subsequently, SM-CYP1A1 mRNA was applied to investigate the biological effect of petroleum hydrocarbon pollution in Quanzhou Bay, China. The transcription levels of hepatic CYP1A1 were significantly elevated in fish caged in the polluted sites for 2weeks compared with those of the reference site, which were correlated with the concentrations of petroleum hydrocarbon and polycyclic aromatic hydrocarbon (PAH) in the surface seawaters. The results suggest that S. marmoratus is a potential sentinel organism to monitor marine pollutants and the hepatic CYP1A1 mRNA can serve as a sensitive biomarker to organic xenobiotics in aquatic environments. Copyright © 2017 Elsevier Ltd. All rights reserved.

  1. First record of the blackfin coral goby, Paragobiodon lacunicolus (Kendall and Goldsborough, 1911), from the Red Sea

    KAUST Repository

    Alpermann, Tilman J.

    2013-09-13

    Three specimens of the blackfin coral goby, Paragobiodon lacunicolus, were collected in 2010 and 2011 at different locations of the eastern Red Sea along the coast of Saudi Arabia. Reexamination of 14 museum specimens from Eritrea also confirmed the presence of the species for the western Red Sea. This represents the first published report of P. lacunicolus from the Red Sea. © 2013 Blackwell Verlag GmbH.

  2. First record of the blackfin coral goby, Paragobiodon lacunicolus (Kendall and Goldsborough, 1911), from the Red Sea

    KAUST Repository

    Alpermann, Tilman J.; Mee, J. K L; Berumen, Michael L.

    2013-01-01

    Three specimens of the blackfin coral goby, Paragobiodon lacunicolus, were collected in 2010 and 2011 at different locations of the eastern Red Sea along the coast of Saudi Arabia. Reexamination of 14 museum specimens from Eritrea also confirmed the presence of the species for the western Red Sea. This represents the first published report of P. lacunicolus from the Red Sea. © 2013 Blackwell Verlag GmbH.

  3. A tough egg to crack: recreational boats as vectors for invasive goby eggs and transdisciplinary management approaches.

    Science.gov (United States)

    Hirsch, Philipp E; Adrian-Kalchhauser, Irene; Flämig, Sylvie; N'Guyen, Anouk; Defila, Rico; Di Giulio, Antonietta; Burkhardt-Holm, Patricia

    2016-02-01

    Non-native invasive species are a major threat to biodiversity, especially in freshwater ecosystems. Freshwater ecosystems are naturally rather isolated from one another. Nonetheless, invasive species often spread rapidly across water sheds. This spread is to a large extent realized by human activities that provide vectors. For example, recreational boats can carry invasive species propagules as "aquatic hitch-hikers" within and across water sheds. We used invasive gobies in Switzerland as a case study to test the plausibility that recreational boats can serve as vectors for invasive fish and that fish eggs can serve as propagules. We found that the peak season of boat movements across Switzerland and the goby spawning season overlap temporally. It is thus plausible that goby eggs attached to boats, anchors, or gear may be transported across watersheds. In experimental trials, we found that goby eggs show resistance to physical removal (90 mN attachment strength of individual eggs) and stay attached if exposed to rapid water flow (2.8 m·s(-1)for 1 h). When exposing the eggs to air, we found that hatching success remained high (>95%) even after eggs had been out of water for up to 24 h. It is thus plausible that eggs survive pick up, within-water and overland transport by boats. We complemented the experimental plausibility tests with a survey on how decision makers from inside and outside academia rate the feasibility of managing recreational boats as vectors. We found consensus that an installation of a preventive boat vector management is considered an effective and urgent measure. This study advances our understanding of the potential of recreational boats to serve as vectors for invasive vertebrate species and demonstrates that preventive management of recreational boats is considered feasible by relevant decision makers inside and outside academia.

  4. Delayed impacts of developmental exposure to 17-α-ethinylestradiol in the self-fertilizing fish Kryptolebias marmoratus.

    Science.gov (United States)

    Voisin, Anne-Sophie; Fellous, Alexandre; Earley, Ryan L; Silvestre, Frédéric

    2016-11-01

    17-α-ethinylestradiol (EE2) is one of the most potent endocrine disrupting compounds found in the aquatic environments, and is known to strongly alter fish reproduction and fitness. While the effects of direct exposure to EE2 are well studied in adults, there is an increasing need to assess the impacts of exposure during early life stages. Sensitivity to pollutants during this critical window can potentially affect the phenotype later in life or in subsequent generations. This study investigated phenotypic outcome of early-life exposure to 17-α-ethinylestradiol during development and in adults of the mangrove rivulus, Kryptolebias marmoratus. Being one of the only two known self-fertilizing hermaphroditic vertebrates, this fish makes it possible to work with genetically identical individuals. Therefore, using rivulus makes it possible to examine, explicitly, the phenotypic effects of environmental variance while eliminating the effects of genetic variance. Genetically identical rivulus were exposed for the first 28days post hatching (dph) to 0, 4 or 120ng/L of EE2, and then were reared in uncontaminated water until 168dph. Growth, egg laying and steroid hormone levels (estradiol, cortisol, 11-ketotestosterone, testosterone) were measured throughout development. Exposed fish showed a reduction in standard length directly after exposure (28dph), which was more pronounced in the 120ng/L group. This was followed by compensatory growth when reared in clean water: all fish recovered a similar size as controls by 91dph. There was no difference in the age at maturity and the proportions of mature, non-mature and male individuals at 168dph. At 4ng/L, fish layed significantly fewer eggs than controls, while, surprisingly, reproduction was not affected at 120ng/L. Despite a decrease in fecundity at 4ng/L, there were no changes in hormones levels at the lower concentration. In addition, there were no significant differences among treatments immediately after exposure

  5. Photoreactivation rescue and dark repair demonstrated in UV-irradiated embryos of the self-fertilizing fish Rivulus ocellatus marmoratus (Teleostei; Aplocheilidae)

    International Nuclear Information System (INIS)

    Park, E.-H.; Yi, A.-K.

    1989-01-01

    The effects of photoreactivation (PR) rescue and dark repair on the survival of UV-irradiated embryos of the hermaphroditic fish (Rivulus ocellatus marmoratus) are reported. When UV-irradiated embryos were illuminated by photoreactivating light (PRL) from fluorescent lamps, survival at the hatching stage was markedly increased. The maximum recovery to UV damage was shown by embryos that were exposed to PRL for at least 6 h after UV irradiation. The effect of PRL decreased 30 min after UV irradiation and not PR rescue ws detected beyond 96 h. Treatment with 2 mM caffeine for 48 h after UV irradiation increased the sensitivity of the embryos in the dark. The above results demonstrate that Rivulus embryos have an efficient PR system and a caffeine-sensitive dark repair capacity. (author). 31 refs.; 5 figs

  6. Do male desert gobies compromise offspring care to attract additional mating opportunities?

    Directory of Open Access Journals (Sweden)

    Nicholas Symons

    Full Text Available Males often play a critical role in offspring care but the time and energy invested in looking after young can potentially limit their ability to seek out additional mating opportunities. Recent studies, however, suggest that a conflict between male parental effort and mating effort may not always be inevitable, especially if breeding occurs near the nest, or if parental behaviours are under sexual selection. Accordingly, we set out to experimentally investigate male care and courtship in the desert goby Chlamydogobius eremius, a nest-guarding fish with exclusive paternal care. Despite courtship occurring near the nest, we found that when egg-tending males were given the opportunity to attract additional females, they fanned their eggs less often, engaged in shorter fanning bouts, and spent more of their time outside their nests courting. Our findings highlight the importance of understanding the circumstances under which reproductive tradeoffs are expected to occur and how these, in turn, operate to influence male reproductive decisions.

  7. Differentiation and adaptive radiation of amphibious gobies (Gobiidae: Oxudercinae) in semi-terrestrial habitats.

    Science.gov (United States)

    Polgar, G; Sacchetti, A; Galli, P

    2010-11-01

    During several surveys made in the region of the lower Fly River and delta, Papua New Guinea, nine species of oxudercine gobies (Gobiidae: Oxudercinae) were recorded: Boleophthalmus caeruleomaculatus, Oxuderces wirzi, Periophthalmodon freycineti, Periophthalmus darwini, Periophthalmus novaeguineaensis, Periophthalmus takita, Periophthalmus weberi, Scartelaos histophorus and Zappa confluentus. An exploratory multivariate analysis of their habitat conditions discriminated five guilds, differentially distributed in habitats with different quantities of environmental water and three guilds corresponding to different levels of salinity. A partial correspondence between phylogenetic and ecological categories suggested the presence of parallel adaptive radiations within different genera. In particular, the species found in the most terrestrial habitats (P. weberi) was also found in the widest range of conditions, suggesting that colonization of extreme semi-terrestrial and freshwater habitats by this species was facilitated by eurytypy. It is proposed that these findings provide insight into convergent adaptations for the vertebrate eco-evolutionary transition from sea to land. © 2010 The Authors. Journal of Fish Biology © 2010 The Fisheries Society of the British Isles.

  8. Malfunction Rates of Bird Flight Diverters on Powerlines in the Mongolian Gobi

    Directory of Open Access Journals (Sweden)

    Batsuuri Dashnyam

    2016-11-01

    Full Text Available The Oyu Tolgoi (OT project, one of the world’s largest copper and gold mines, is located in Gobi Desert of Mongolia. To help meet its target of Net Positive Impact on key biodiversity features such as the Houbara bustard (Chlamydotis undulata the OT installed bird fl ight diverters (BFDs include spiral and fl apper devices to its power transmission lines to reduce the risk of birds hitting the wires. Despite the many studies demonstrating that BFDs reduce collision rates, we could fi nd no published information on malfunction rates of BFDs. In January 2013, we surveyed the physical function of 1,200 BFDs (e.g. 600 fl appers and 600 spirals in three sample areas on each of four lines of varying voltage and structure. Of the 600 fl appers examined, 123 had malfunctioned within nine months of installation, while the malfunction rate of the 600 spirals studied was zero. Using a Generalized Linear Mixed Model, we found that the rate of fl apper malfunction increased with decreasing fl apper size and power line diameter. Further, the fl apper malfunction rate increased as the distance between poles increased. The cost of replacing malfunctioning BFDs is very high as there are serious health and safety constraints related to working with live wires. Factors aff ecting diverter malfunctioning need to be considered for future powerline projects and our information can serve as basis for developing national standards or regulations for powerline mitigation in Mongolia.

  9. Specific characteristics of essential oils of four Artemisia species from the Mongolian Trans-Altai Gobi

    Directory of Open Access Journals (Sweden)

    N. Javzmaa

    2016-03-01

    Full Text Available The essential oil compositions of four Artemisia species in Mongolian Trans-Altai Gobi were studied by gas chromatography (GC and gas chromatography-mass spectrometry (GC-MS. The oil from A.macrocephala Jacq and A.dracunculus Ledeb. were characterized by the presence of monoterpene hydrocarbons and oxygenated monoterpeneoids predominately. E-nerolidol (26.95%, methyleugenol (23.29% and sabinene (13.21% were found as main components in the essential oils of A.dracunculus. A.macrocephalla was characterized by the presence of chamazulene (13.8%, cineol (11.7%, myrcene (9.0%, germacrene-D (7.1%. A.anethifolia Web was characterized by the presence of fragrant compounds as camphor (26.05%, α-thujone (10.1%, borneol (5.1%. Davanone and davanone derivatives were also detected in the sample in amount of 7.7% in total. A.scoparia Waldst differed by domination of monoterpene hydrocarbons (78.9% with (Z- β-ocimene (29.24%, α-pinene (15.19%, limonene (10.27% and myrcene (9.61%.Mongolian Journal of Chemistry 16 (42, 2015, 34-38

  10. Bacterial diversity of surface sand samples from the Gobi and Taklamaken deserts.

    Science.gov (United States)

    An, Shu; Couteau, Cécile; Luo, Fan; Neveu, Julie; DuBow, Michael S

    2013-11-01

    Arid regions represent nearly 30 % of the Earth's terrestrial surface, but their microbial biodiversity is not yet well characterized. The surface sands of deserts, a subset of arid regions, are generally subjected to large temperature fluctuations plus high UV light exposure and are low in organic matter. We examined surface sand samples from the Taklamaken (China, three samples) and Gobi (Mongolia, two samples) deserts, using pyrosequencing of PCR-amplified 16S V1/V2 rDNA sequences from total extracted DNA in order to gain an assessment of the bacterial population diversity. In total, 4,088 OTUs (using ≥97 % sequence similarity levels), with Chao1 estimates varying from 1,172 to 2,425 OTUs per sample, were discernable. These could be grouped into 102 families belonging to 15 phyla, with OTUs belonging to the Firmicutes, Proteobacteria, Bacteroidetes, and Actinobacteria phyla being the most abundant. The bacterial population composition was statistically different among the samples, though members from 30 genera were found to be common among the five samples. An increase in phylotype numbers with increasing C/N ratio was noted, suggesting a possible role in the bacterial richness of these desert sand environments. Our results imply an unexpectedly large bacterial diversity residing in the harsh environment of these two Asian deserts, worthy of further investigation.

  11. Determination of phase compositions in ceramics from Gobi desert using complementary diffraction techniques

    International Nuclear Information System (INIS)

    Gilles, R.; Hoelzel, M.; Siouris, I.M.; Katsavounis, S.; Visser, D.; Brunelli, M.

    2013-01-01

    The city Khara Khoto is located in the Gobi desert in Inner Mongolia. This city was deserted in the late 14th century and rediscovered in the beginning of the 20th century. In the present study, ceramic sherds typical for the Khara Khoto area have been analysed using neutrons, laboratory X-ray diffraction, synchrotron radiation X-ray diffraction as well as optical microscopy as complementary probes in extracting information on the mineral phase compositions as well as on the firing conditions during the pottery production. The data evaluation was performed with the standard diffraction analysis package GSAS and the new developed program AmPhOrAe. The dominating phase is mullite (∼60 %) compared to a variable mixture of SiO 2 quartz and cristobalite phases (∼35 %) and feldspar as a minority phase. Refiring experiments on one of the sherds allow estimating the firing temperatures of the ceramics within the region of 1,150 and 1,250 deg C. (author)

  12. Fungal Ferromanganese Mineralisation in Cretaceous Dinosaur Bones from the Gobi Desert, Mongolia.

    Science.gov (United States)

    Owocki, Krzysztof; Kremer, Barbara; Wrzosek, Beata; Królikowska, Agata; Kaźmierczak, Józef

    2016-01-01

    Well-preserved mycelia of fungal- or saprolegnia-like biota mineralised by ferromanganese oxides were found for the first time in long bones of Late Cretaceous dinosaurs from the Gobi Desert (Nemegt Valley, Mongolia). The mycelia formed a biofilm on the wall of the bone marrow cavity and penetrated the osteon channels of the nearby bone tissue. Optical microscopy, Raman, SEM/EDS, SEM/BSE, electron microprobe and cathodoluminescence analyses revealed that the mineralisation of the mycelia proceeded in two stages. The first stage was early post-mortem mineralisation of the hyphae by Fe/Mn-oxide coatings and microconcretions. Probably this proceeded in a mildly acidic to circumneutral environment, predominantly due to heterotrophic bacteria degrading the mycelial necromass and liberating Fe and Mn sorbed by the mycelia during its lifetime. The second stage of mineralisation, which proceeded much later following the final burial of the bones in an alkaline environment, resulted from the massive precipitation of calcite and occasionally barite on the iron/manganese-oxide-coated mycelia. The mineral phases produced by fungal biofilms colonising the interiors of decaying dinosaur bones not only enhance the preservation (fossilisation) of fungal remains but can also be used as indicators of the geochemistry of the dinosaur burial sites.

  13. Fish embryos on land: terrestrial embryo deposition lowers oxygen uptake without altering growth or survival in the amphibious fish Kryptolebias marmoratus.

    Science.gov (United States)

    Wells, Michael W; Turko, Andy J; Wright, Patricia A

    2015-10-01

    Few teleost fishes incubate embryos out of water, but the oxygen-rich terrestrial environment could provide advantages for early growth and development. We tested the hypothesis that embryonic oxygen uptake is limited in aquatic environments relative to air using the self-fertilizing amphibious mangrove rivulus, Kryptolebias marmoratus, which typically inhabits hypoxic, water-filled crab burrows. We found that adult mangrove rivulus released twice as many embryos in terrestrial versus aquatic environments and that air-reared embryos had accelerated developmental rates. Surprisingly, air-reared embryos consumed 44% less oxygen and possessed larger yolk reserves, but attained the same mass, length and chorion thickness. Water-reared embryos moved their opercula ∼2.5 more times per minute compared with air-reared embryos at 7 days post-release, which probably contributed to the higher rates of oxygen uptake and yolk utilization we observed. Genetically identical air- and water-reared embryos from the same parent were raised to maturity, but the embryonic environment did not affect growth, reproduction or emersion ability in adults. Therefore, although aspects of early development were plastic, these early differences were not sustained into adulthood. Kryptolebias marmoratus embryos hatched out of water when exposed to aerial hypoxia. We conclude that exposure to a terrestrial environment reduces the energetic costs of development partly by reducing the necessity of embryonic movements to dispel stagnant boundary layers. Terrestrial incubation of young would be especially beneficial to amphibious fishes that occupy aquatic habitats of poor water quality, assuming low terrestrial predation and desiccation risks. © 2015. Published by The Company of Biologists Ltd.

  14. (Hyperolius marmoratus) populations

    African Journals Online (AJOL)

    How far can reed frogs migrate and maintain gene- flow when bced by barriers of unsuitable habitat and sepa- rated by considerable geographical distances? ..... IAGEID. S.S. 1994. Lb:tropllOn:tic and morphometric cviucl1(;c for t\\\\O species of the genus Hana (Amphibia, Ranidae) and sum oftheir vari

  15. Standardization of plasma vitellogenin level for surveying environmental estrogen pollution using the Japanese common goby Acanthogobius flavimanus.

    Science.gov (United States)

    Song, Jing; Nagae, Masaki; Soyano, Kiyoshi

    2018-07-01

    Field surveys of the impact of environmental estrogen (EE) pollution in aquatic wildlife have been conducted using vitellogenin (VTG) as a biomarker to evaluate the influence of EE. However, a standard baseline of VTG level that can be used to evaluate EE pollution has not been fully determined. To the best of our knowledge, the present study is the first to determine the standard baseline VTG level for evaluating the biological effects of EE pollution using the Japanese common goby (Acanthogobius flavimanus) as the target model fish. Plasma VTG and estradiol-17β (E 2 ) levels associated with the reproductive cycle of wild goby inhabiting an unpolluted environment were measured. Mean plasma VTG and E 2 levels exhibited similar changes, increasing in the yolk vesicle stage and peaking in the tertiary yolk stage in females. However, plasma VTG and E 2 levels showed no significant changes in males, remaining at low levels throughout the reproductive cycle. The highest VTG levels in females and males were 1.6 mg ml -1 and 124.87 ng ml -1 , respectively. These results indicate that the baseline level (normal level) in males was approximately 130 ng ml -1 at most. We concluded that the threshold between normal and abnormal levels with a 10% risk rate was 150 ng ml -1 in the wild male goby. Plasma VTG levels in males captured from Nagasaki Harbor were higher than the threshold in each reproductive developmental stage, indicating the possibility of EE pollution at this site. The biological standard baseline for VTG established in this study is useful for assessing EE pollution in natural waters. Copyright © 2018 John Wiley & Sons, Ltd.

  16. A New Species of the Bay Goby Genus Eucyclogobius, Endemic to Southern California: Evolution, Conservation, and Decline.

    Directory of Open Access Journals (Sweden)

    Camm C Swift

    Full Text Available A geographically isolated set of southern localities of the formerly monotypic goby genus Eucyclogobius is known to be reciprocally monophyletic and substantially divergent in mitochondrial sequence and nuclear microsatellite-based phylogenies relative to populations to the north along the California coast. To clarify taxonomic and conservation status, we conducted a suite of analyses on a comprehensive set of morphological counts and measures from across the range of Eucyclogobius and describe the southern populations as a new species, the Southern Tidewater Goby, Eucyclogobius kristinae, now separate from the Northern Tidewater Goby Eucyclogobius newberryi (Girard 1856. In addition to molecular distinction, adults of E. kristinae are diagnosed by: 1 loss of the anterior supratemporal lateral-line canals resulting in higher neuromast counts, 2 lower pectoral and branched caudal ray counts, and 3 sets of measurements identified via discriminant analysis. These differences suggest ecological distinction of the two species. Previous studies estimated lineage separation at 2-4 million years ago, and mitochondrial sequence divergence exceeds that of other recognized fish species. Fish from Santa Monica Artesian Springs (Los Angeles County northward belong to E. newberryi; those from Aliso Creek (Orange County southward constitute E. kristinae. The lagoonal habitat of Eucyclogobius has been diminished or degraded, leading to special conservation status at state and federal levels beginning in 1980. Habitat of the newly described species has been impacted by a range of anthropogenic activities, including the conversion of closing lagoons to open tidal systems in the name of restoration. In the last 30 years, E. kristinae has only been observed in nine intermittently occupied lagoonal systems in northern San Diego County; it currently persists in only three sites. Thus, the new species is in imminent danger of extinction and will require ongoing active

  17. How old are you—Evaluation of age reading methods for the invasive round goby (Neogobius melanostomus, Pallas 1814)

    DEFF Research Database (Denmark)

    Florin, Ann-Britt; Hüssy, Karin; Blass, M.

    2018-01-01

    for an increasing knowledge of their basic stock structures such as growth rates, longevity and mortality, which all rely on accurate estimates of age. Former studies on the round goby have used several different age reading techniques. In this study, we compared three standard otolith preparation methods...... agreement was lowest when reading the whole otoliths while the best performance was achieved with sectioned and stained preparation method. Depending on method used the growth estimates also differed. The results question comparability between previous studies and highlight the importance of harmonised...

  18. Prey preference of snow leopard (Panthera uncia in South Gobi, Mongolia.

    Directory of Open Access Journals (Sweden)

    Wasim Shehzad

    Full Text Available Accurate information about the diet of large carnivores that are elusive and inhabit inaccessible terrain, is required to properly design conservation strategies. Predation on livestock and retaliatory killing of predators have become serious issues throughout the range of the snow leopard. Several feeding ecology studies of snow leopards have been conducted using classical approaches. These techniques have inherent limitations in their ability to properly identify both snow leopard feces and prey taxa. To examine the frequency of livestock prey and nearly-threatened argali in the diet of the snow leopard, we employed the recently developed DNA-based diet approach to study a snow leopard population located in the Tost Mountains, South Gobi, Mongolia. After DNA was extracted from the feces, a region of ∼100 bp long from mitochondrial 12S rRNA gene was amplified, making use of universal primers for vertebrates and a blocking oligonucleotide specific to snow leopard DNA. The amplicons were then sequenced using a next-generation sequencing platform. We observed a total of five different prey items from 81 fecal samples. Siberian ibex predominated the diet (in 70.4% of the feces, followed by domestic goat (17.3% and argali sheep (8.6%. The major part of the diet was comprised of large ungulates (in 98.8% of the feces including wild ungulates (79% and domestic livestock (19.7%. The findings of the present study will help to understand the feeding ecology of the snow leopard, as well as to address the conservation and management issues pertaining to this wild cat.

  19. Survival, growth and stress response of juvenile tidewater goby, Eucyclogobius newberryi, to interspecific competition for food

    Science.gov (United States)

    Chase, Daniel A; Flynn, Erin E; Todgham, Anne E

    2016-01-01

    Abstract Reintroduction of endangered fishes to historic habitat has been used as a recovery tool; however, these fish may face competition from other fishes that established in their native habitat since extirpation. This study investigated the physiological response of tidewater goby, Eucyclogobius newberryi, an endangered California fish, when competing for food with threespine stickleback, Gasterosteus aculeatus, a native species, and rainwater killifish, Lucania parva, a non-native species. Survival, growth and physiological indicators of stress (i.e. cortisol, glucose and lactate concentrations) were assessed for juvenile fish held for 28 days in two food-limited conditions. When fed a 75% ration, survival of E. newberryi was significantly lower when held with G. aculeatus. In all fish assemblages, weight and relative condition decreased then stabilized over the 28 day experiment, while length remained unchanged. Whole-body cortisol in E. newberryi was not affected by fish assemblage; however, glucose and lactate concentrations were significantly higher with conspecifics than with other fish assemblages. When fed a 50% ration, survival of E. newberryi decreased during the second half of the experiment, while weight and relative condition decreased and length remained unchanged in all three fish assemblages. Cortisol concentrations were significantly higher for all fish assemblages compared with concentrations at the start of the experiment, whereas glucose and lactate concentrations were depressed relative to concentrations at the start of the experiment, with the magnitude of decrease dependent on the species assemblage. Our findings indicate that E. newberryi exhibited reduced growth and an elevated generalized stress response during low food availability. In response to reduced food availability, competition with G. aculeatus had the greatest physiological effect on E. newberryi, with minimal effects from the non-native L. parva. This study presents

  20. Point irrigation for locality Buchel in the north desert Gobi in Mongolia

    Directory of Open Access Journals (Sweden)

    Pavel Spitz

    2009-01-01

    Full Text Available The design of point irrigation, created by Filip et al. (2007, was worked up as the bilateral projekt in the frame of abroad developing cooperation between the Czech Republic and Mongolia „Rehabilitation of plant production in semiarid territories of northern Gobi”. The period of project realization are years 2006–2009. The responsible institution for the project is Ministery of Agriculture of the Czech Republic and with the realization of the project was encharged Mendel University of Agriculture and Forestry in Brno. The task was work irrigation design for experimental plants and vegetables on the choosen land in Gobi desert in Mongolia. To disposition was underground water source – bore with capacity about 2 l / s and temperature about 10 °C, electric power and land about area cca 1 ha. The condition was use simple irrigation equipment. The fundamental limitation was im­pos­si­bi­li­ty using technically more complex and more sophisticated equipment e.g. drip irrigation. The map was not to the disposition, only a judgment of slope 0,2 % in flat terrain. The technical design of surface and subsurface point irrigation are introduced, shortly described are hydrotechnical basis used to created and described the original PC program HYBOZAM (hydraulics of point irrigation for Mongolia developed in table editor of Microsoft Excel for pipe dimensions of point irrigation design. Part of the program is also evaluation of the irrigation uniformity from outflows on irrigation line.

  1. Comparison of the Visual Capabilities of an Amphibious and an Aquatic Goby That Inhabit Tidal Mudflats.

    Science.gov (United States)

    Takiyama, Tomo; Hamasaki, Sawako; Yoshida, Masayuki

    2016-01-01

    The mudskipper Periophthalmus modestus and the yellowfin goby Acanthogobius flavimanus are gobiid teleosts that both inhabit the intertidal mudflats in estuaries. While P. modestus has an amphibious lifestyle and forages on the exposed mudflat during low tide, the aquatic A. flavimanus can be found at the same mudflat at high tide. This study primarily aimed to elucidate the differential adaptations of these organisms to their respective habitats by comparing visual capacities and motor control in orienting behavior during prey capture. Analyses of retinal ganglion cell topography demonstrated that both species possess an area in the dorsotemporal region of the retina, indicating high acuity in the lower frontal visual field. Additionally, P. modestus has a minor area in the nasal portion of the retina near the optic disc. The horizontally extended specialized area in P. modestus possibly reflects the need for optimized horizontal sight on the exposed mudflat. Behavioral experiments to determine postural and eye direction control when orienting toward the object of interest revealed that these species direct their visual axes to the target situated below eye level just before a rapid approach toward it. A characteristic feature of the orienting behavior of P. modestus was that they aimed at the target by using the specialized retinal area by rotating the eye and lifting the head before jumping to attack the target located above eye level. This behavior could be an adaptation to a terrestrial feeding habitat in which buoyancy is irrelevant. This study provides insights into the adaptive mechanisms of gobiid species and the evolutionary changes enabling them to forage on land. © 2016 S. Karger AG, Basel.

  2. From sneaker to parental male: change of reproductive traits in the black goby, Gobius niger (Teleostei, Gobiidae).

    Science.gov (United States)

    Immler, Simone; Mazzoldi, Carlotta; Rasotto, Maria Berica

    2004-02-01

    This study focuses on the consequences of the switch of tactic from parasitic to parental male in the black goby, Gobius niger (Teleostei: Gobiidae), a species showing two alternative male mating tactics. Older and larger males defend nests, court, and perform parental care on eggs, while younger and smaller ones behave as parasites, sneaking into nests while spawning occurs. Males adopting different tactics are known to present differences in primary and secondary sex traits. The social context of sneaker males was manipulated to induce a tactic switch. Sneakers were kept under two different experimental treatments with or without a female, and under exclusion of male-male competition. Males changed tactics, courting females, spawning, and performing parental care. All males showed substantial changes in primary sexual traits, such as a reduction in gonadal development and an increase in the investment in accessory structures. The experimental groups differed in the functionality of gonads and accessory organs and in the development of the secondary sex traits. These results demonstrate that the moment of switching is not genetically fixed in the black goby. Sneaker males are able to quickly reallocate energy in primary and secondary sex traits, in accordance with the adopted tactic. Several aspects of this flexible reproductive pattern resemble the socially controlled sex change found in sequential hermaphrodites. Copyright 2004 Wiley-Liss, Inc.

  3. Comparison of metallothionein concentrations and tissue distribution of trace metals in crabs (Pachygrapsus marmoratus) from a metal-rich estuary, in and out of the reproductive season.

    Science.gov (United States)

    Mouneyrac, C; Amiard-Triquet, C; Amiard, J C; Rainbow, P S

    2001-07-01

    Crabs, Pachygrapsus marmoratus, were sampled in June 1997 and February 1998 from two sites (at the mouth and 25 km upstream) in the metal-rich Gironde estuary, France. Gills and hepatopancreas were analysed for metal (Cd, Cu, Zn) and metallothionein (MT) contents, in order to examine the influence of both biological and environmental factors on the physico-chemical forms of detoxified metal storage in the crabs. The concentrations of MT and both cytosolic and insoluble metals were not greatly different between males and females, and the influence of organ weights was also minimal. Intersite differences were observed, probably resulting from the gradient of salinity in the estuary, which interacts with both the chemical speciation and bioavailability of metals, and the general protein metabolism of the crabs. Seasonal changes were also important, probably in interaction with the moult and reproductive cycles. In February, concentrations of insoluble metals were generally higher than in June, in both organs, suggesting that essential metals, particularly Zn, are stored during winter then remobilised during the breeding season. The natural variability in the concentrations of MT often concealed any relationship with accumulated metal concentrations. Thus MT in crabs cannot be considered as a useful biomarker of metal pollution.

  4. Out of the frying pan into the air--emersion behaviour and evaporative heat loss in an amphibious mangrove fish (Kryptolebias marmoratus).

    Science.gov (United States)

    Gibson, Daniel J; Sylvester, Emma V A; Turko, Andy J; Tattersall, Glenn J; Wright, Patricia A

    2015-10-01

    Amphibious fishes often emerse (leave water) when faced with unfavourable water conditions. How amphibious fishes cope with the risks of rising water temperatures may depend, in part, on the plasticity of behavioural mechanisms such as emersion thresholds. We hypothesized that the emersion threshold is reversibly plastic and thus dependent on recent acclimation history rather than on conditions during early development. Kryptolebias marmoratus were reared for 1 year at 25 or 30°C and acclimated as adults (one week) to either 25 or 30°C before exposure to an acute increase in water temperature. The emersion threshold temperature and acute thermal tolerance were significantly increased in adult fish acclimated to 30°C, but rearing temperature had no significant effect. Using a thermal imaging camera, we also showed that emersed fish in a low humidity aerial environment (30°C) lost significantly more heat (3.3°C min(-1)) than those in a high humidity environment (1.6°C min(-1)). In the field, mean relative humidity was 84%. These results provide evidence of behavioural avoidance of high temperatures and the first quantification of evaporative cooling in an amphibious fish. Furthermore, the avoidance response was reversibly plastic, flexibility that may be important for tropical amphibious fishes under increasing pressures from climatic change. © 2015 The Author(s).

  5. Out of the frying pan into the air—emersion behaviour and evaporative heat loss in an amphibious mangrove fish (Kryptolebias marmoratus)

    Science.gov (United States)

    Gibson, Daniel J.; Sylvester, Emma V. A.; Turko, Andy J.; Tattersall, Glenn J.; Wright, Patricia A.

    2015-01-01

    Amphibious fishes often emerse (leave water) when faced with unfavourable water conditions. How amphibious fishes cope with the risks of rising water temperatures may depend, in part, on the plasticity of behavioural mechanisms such as emersion thresholds. We hypothesized that the emersion threshold is reversibly plastic and thus dependent on recent acclimation history rather than on conditions during early development. Kryptolebias marmoratus were reared for 1 year at 25 or 30°C and acclimated as adults (one week) to either 25 or 30°C before exposure to an acute increase in water temperature. The emersion threshold temperature and acute thermal tolerance were significantly increased in adult fish acclimated to 30°C, but rearing temperature had no significant effect. Using a thermal imaging camera, we also showed that emersed fish in a low humidity aerial environment (30°C) lost significantly more heat (3.3°C min−1) than those in a high humidity environment (1.6°C min−1). In the field, mean relative humidity was 84%. These results provide evidence of behavioural avoidance of high temperatures and the first quantification of evaporative cooling in an amphibious fish. Furthermore, the avoidance response was reversibly plastic, flexibility that may be important for tropical amphibious fishes under increasing pressures from climatic change. PMID:26490418

  6. Multitasking in an eye: the unusual organization of the Thermonectus marmoratus principal larval eyes allows for far and near vision and might aid in depth perception.

    Science.gov (United States)

    Stowasser, Annette; Buschbeck, Elke K

    2014-07-15

    Very few visual systems diverge fundamentally from the basic plans of well-studied animal eyes. However, investigating those that do can provide novel insights into visual system function. A particularly unusual system exists in the principal larval eyes of a visually guided aquatic predator, the sunburst diving beetle, Thermonectus marmoratus (Coleoptera: Dystiscidae). These eyes are characterized by complex layered distal and proximal retinas. We previously reported that their principal eye E2 has a bifocal lens, and previous behavioral experiments suggested that these larvae have a unilateral range-finding mechanism that may involve their bizarre eye organization. In the present study, we expanded our optical measurements and found that: (1) E1 also has a bifocal lens, (2) E1 is best suited for far vision while E2 is best suited for near vision and (3) throughout their typical hunting range, the positions of focused images shift across specific retinal layers. This anatomical and optical organization in principle could support unilateral range finding. Taken together, our findings outline an unusual visual mechanism that is likely to be essential for the extraordinary hunting ability of these larvae. © 2014. Published by The Company of Biologists Ltd.

  7. Stable isotopes suggest differences in diet between historic and reintroduced Przewalskís horses in the Gobi desert

    Science.gov (United States)

    Burnik Šturm, Martina; Spasskaya, Natalia N.; Sablin, Mikhail V.; Voigt, Christian C.; Kaczensky, Petra

    2016-04-01

    In historic times, two wild equid species, the Przewalski᾽s horse (PH; Equus ferus przewalskii) and the Asiatic wild ass (khulan, KH; Equus hemionus), roamed the Eurasian steppes. By the end of the 1960s, PHs had been driven to extinction in the wild and the range of KHs became severely restricted to the least productive habitats. However, PHs survived in captivity and reintroductions since the 1990s have brought the species back to parts of its native range in Mongolia and northern China where they again overlap with KHs. Ecological research on PHs and KHs has increased in recent years, but very little information is available on the ecology of the original PHs prior to extinction in the wild. We applied stable isotope analysis (13C, 15N, and 2H) of segmentally cut tail hair of PHs and KHs, collected during expeditions in NW China and SW Mongolia in 1889-1899, to draw inferences about the species feeding ecology. We compared tail hair isotope patterns of historic individuals to those of their extant counterparts from the Mongolian Gobi. A previous study of isotopic tail hair signatures of extant PHs (N=6) and KHs (N=6) suggested species specific differences in diet, with PHs being year-round grazers, but KHs switching between being grazers in summer and mixed feeders in winter (Burnik Šturm et al., in prep.). The comparison of isotope patterns of extant with historic samples confirms diet seasonality in historic KHs (N=3), but detects the same seasonality in five out of six PHs, suggesting that historic PHs had a different isotopic dietary niche than extant PHs. While we are still unable to fully understand the underlying reasons for this change in PHs, our results clearly suggest that the isotopic dietary niche of PHs was wider in the past, suggesting a higher diet flexibility, and overlapped with that of KHs, suggesting a high competition potential over Gobi pastures between the two equid species in historic times. Reference: Burnik Šturm, M., Ganbaatar, O

  8. A new mesophotic goby, Palatogobius incendius (Teleostei: Gobiidae, and the first record of invasive lionfish preying on undescribed biodiversity.

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    Luke Tornabene

    Full Text Available A new species of deep-reef fish in the goby genus Palatogobius is described from recent submersible collections off Curaçao and Dominica. Video footage of schools of this species reveal predation by the invasive Indo-Pacific lionfish (Pterois spp., the first record of undescribed fauna potentially being eaten by lionfish outside of its native range. We present molecular phylogenetic data for all valid species of Palatogobius and related genera, as well as a taxonomic key to the species of Palatogobius and a generic key to Palatogobius and related genera in the western Atlantic. Lastly, we discuss ecological and behavioral aspects of some deep-reef fishes in light of potential threats from invasive lionfish.

  9. First record of Pontian Monkey Goby, Neogobius fluviatilis (Pallas, 1814 in the Evros River (Greece; Is it an alien species?

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    S. ZOGARIS

    2011-11-01

    Full Text Available The Pontian Monkey Goby,Neogobius fluviatilis (Pallas, 1814, was recorded for the first time in Greece in August 2011. Eight specimens were collected in the Greek-Turkish section of the Evros River, 65 kilometers upstream of its river-mouth. Although the species has been recently discovered in the Tundza, a tributary of the Evros in Bulgaria, it has never before been found in the Evros’ main stem.  Although the lower Evros has been poorly researched by ichthyologists, it is unlikely that a conspicuous medium-sized fish would go unnoticed in this river; and, it is therefore suggested to be a probable alien. However, since the Evros basin has had geological connections to the Marmara Sea and Black Sea in the past and it is immediately adjacent to native populations of N. fluviatilis, the species status is categorized as questionable until genetic and morphological studies are completed.

  10. A new mesophotic goby, Palatogobius incendius (Teleostei: Gobiidae), and the first record of invasive lionfish preying on undescribed biodiversity.

    Science.gov (United States)

    Tornabene, Luke; Baldwin, Carole C

    2017-01-01

    A new species of deep-reef fish in the goby genus Palatogobius is described from recent submersible collections off Curaçao and Dominica. Video footage of schools of this species reveal predation by the invasive Indo-Pacific lionfish (Pterois spp.), the first record of undescribed fauna potentially being eaten by lionfish outside of its native range. We present molecular phylogenetic data for all valid species of Palatogobius and related genera, as well as a taxonomic key to the species of Palatogobius and a generic key to Palatogobius and related genera in the western Atlantic. Lastly, we discuss ecological and behavioral aspects of some deep-reef fishes in light of potential threats from invasive lionfish.

  11. A study of variation characteristics of Gobi broadband emissivity based on field observational experiments in northwestern China

    Science.gov (United States)

    Zheng, Zhi-yuan; Wei, Zhi-gang; Wen, Zhi-ping; Dong, Wen-jie; Li, Zhen-chao; Wen, Xiao-hang; Zhu, Xian; Chen, Chen; Hu, Shan-shan

    2018-02-01

    Land surface emissivity is a significant variable in energy budgets, land cover assessments, and environment and climate studies. However, the assumption of an emissivity constant is being used in Gobi broadband emissivity (GbBE) parameterization scheme in numerical models because of limited knowledge surrounding the spatiotemporal variation characteristics of GbBE. To address this issue, we analyzed the variation characteristics of GbBE and possible impact factor-surface soil moisture based on long-term continuous and high temporal resolution field observational experiments over a typical Gobi underlying surface in arid and semiarid areas in northwestern China. The results indicate that GbBE has obvious daily and diurnal variation features, especially diurnal cycle characteristics. The multi-year average of the daily average of GbBE is in the range of 0.932 to 0.970 with an average of 0.951 ± 0.008, and the average diurnal GbBE is in the range of 0.880 to 0.940 with an average of 0.906 ± 0.018. GbBE varies with surface soil moisture content. We observed a slight decrease in GbBE with an increase in soil moisture, although this change was not very obvious because of the low soil moisture in this area. Nevertheless, we think that soil moisture must be one of the most significant impact factors on GbBE in arid and semiarid areas. Soil moisture must be taken into account into the parameterization schemes of bare soil broadband emissivity in land surface models. Additional field experiments and studies should be carried out in order to clarify this issue.

  12. Late Quaternary strike-slip along the Taohuala Shan-Ayouqi fault zone and its tectonic implications in the Hexi Corridor and the southern Gobi Alashan, China

    Science.gov (United States)

    Yu, Jing-xing; Zheng, Wen-jun; Zhang, Pei-zhen; Lei, Qi-yun; Wang, Xu-long; Wang, Wei-tao; Li, Xin-nan; Zhang, Ning

    2017-11-01

    The Hexi Corridor and the southern Gobi Alashan are composed of discontinuous a set of active faults with various strikes and slip motions that are located to the north of the northern Tibetan Plateau. Despite growing understanding of the geometry and kinematics of these active faults, the late Quaternary deformation pattern in the Hexi Corridor and the southern Gobi Alashan remains controversial. The active E-W trending Taohuala Shan-Ayouqi fault zone is located in the southern Gobi Alashan. Study of the geometry and nature of slip along this fault zone holds crucial value for better understanding the regional deformation pattern. Field investigations combined with high-resolution imagery show that the Taohuala Shan fault and the E-W trending faults within the Ayouqi fault zone (F2 and F5) are left-lateral strike-slip faults, whereas the NW or WNW-trending faults within the Ayouqi fault zone (F1 and F3) are reverse faults. We collected Optically Stimulated Luminescence (OSL) and cosmogenic exposure age dating samples from offset alluvial fan surfaces, and estimated a vertical slip rate of 0.1-0.3 mm/yr, and a strike-slip rate of 0.14-0.93 mm/yr for the Taohuala Shan fault. Strata revealed in a trench excavated across the major fault (F5) in the Ayouqi fault zone and OSL dating results indicate that the most recent earthquake occurred between ca. 11.05 ± 0.52 ka and ca. 4.06 ± 0.29 ka. The geometry and kinematics of the Taohuala Shan-Ayouqi fault zone enable us to build a deformation pattern for the entire Hexi Corridor and the southern Gobi Alashan, which suggest that this region experiences northeastward oblique extrusion of the northern Tibetan Plateau. These left-lateral strike-slip faults in the region are driven by oblique compression but not associated with the northeastward extension of the Altyn Tagh fault.

  13. Anticipation of Artemia sp. supply in the larviculture of the barber goby Elacatinus figaro (Gobiidae: Teleostei influenced growth, metamorphosis and alkaline protease activity

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    Maria Fernanda da Silva-Souza

    2015-09-01

    Full Text Available The barber goby Elacatinus figaro is considered endangered due to overexploitation by the ornamental industry. Farming marine ornamental fishes, especially the threatened ones, can be one of the measures to minimize the pressure on the natural stocks. Among the priority issues for their production is the determination of the most appropriate feeding management. The feeding protocol commonly used in the larviculture of barber goby, when the start of Artemia sp. offer occurred at the 18th DAH (days after hatching (treatment T18, was modified, by anticipating brine shrimp supply in 6 days (treatment T12. Alkaline proteases activity, growth and metamorphosis of larvae were evaluated in both protocols. Juveniles at T12 showed higher weight (0.04 ± 0.001 g and lower activity of total alkaline proteases (1.3 ± 0.2 mU mg-1 protein compared to T18 (0.02 ± 0.001 g; 2.8 ± 0.4 mU mg-1 protein, respectively. With anticipation of brine shrimp, the commencing and end of larval transformation was observed earlier (at 24 and 34 DAH, respectively in comparison to those with the supply of Artemia sp. at 18 DAH (27 and 41 DAH, respectively. Thus, the Artemia sp. anticipation was beneficial during the larviculture of the barber goby, considering that larvae reached metamorphosis earlier.

  14. Double origin of the racer goby (Babka gymnotrachelus in Poland revealed with mitochondrial marker. Possible implications for the species alien/native status

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    Michal Grabowski

    2015-09-01

    Full Text Available In mid-1990s racer goby, Babka gymnotrachelus, penetrated to the Vistula and Western Bug rivers in Poland through the canal connecting the Baltic and the Black Sea basins, namely the Vistula and Dnieper drainages. In early 2000s, the species was reported from Polish section of the Strwiąż River that is an affluent of the Dniester River that drains to the Black Sea basin. According to the Polish legislation, the racer goby has been enlisted in as an alien invasive species that may pose threat to local biota. Our analysis of the mtDNA cytochrome b diversity revealed that the Vistula/Western Bug and Strwiąż populations are different genetic units. First one originated from the Dnieper River, while the second derives from the Dniester River. According to the results of mismatch analysis, both are in the stage of demographic and spatial expansion. The haplotype frequencies in population from the Vistula/Western Bug differ significantly from those in the source population in Dnieper, suggesting founder effect, possibly due to human-mediated introduction of low number of individuals. On the other side, the population in Strwiąż does not differ in structure from the one in Dniester, providing a hint towards spontaneous range expansion. Interpretation of our results in light of historical data lead to the conclusion that presence of racer goby in Strwiąż was probably overlooked in previous, spatially limited, studies. Thus, in Strwiąż the species should not be treated as alien, contrary to its status in the Vistula drainage. This double origin of racer goby populations in Poland creates a peculiar situation for national legislation procedures as one population is alien and invasive, while the other one is not. In light of our findings, the population from Strwiąż should be recognised as a special case. Steps should be undertaken to raise public awareness to prevent translocation of the gobies between the rivers to prevent deterioration of the

  15. Habitat selection of two gobies (Microgobius gulosus, Gobiosoma robustum): influence of structural complexity, competitive interactions and presence of a predator

    Science.gov (United States)

    Schofield, P.J.

    2003-01-01

    Herein I compare the relative importance of preference for structurally complex habitat against avoidance of competitors and predators in two benthic fishes common in the Gulf of Mexico. The code goby Gobiosoma robustum Ginsburg and clown goby Microgobius gulosus (Girard) are common, ecologically similar fishes found throughout the Gulf of Mexico and in the southeastern Atlantic Ocean. In Florida Bay, these fishes exhibit habitat partitioning: G. robustum is most abundant in seagrass-dominated areas while M. gulosus is most abundant in sparsely vegetated habitats. In a small-scale field survey, I documented the microhabitat use of these species where their distributions overlap. In a series of laboratory experiments, I presented each species with structured (artificial seagrass) versus nonstructured (bare sand) habitats and measured their frequency of choosing either habitat type. I then examined the use of structured versus nonstructured habitats when the two species were placed together in a mixed group. Finally, I placed a predator (Opsanus beta) in the experimental aquaria to determine how its presence influenced habitat selection. In the field, G. robustum was more abundant in seagrass and M. gulosus was more abundant in bare mud. In the laboratory, both species selected grass over sand in allopatry. However, in sympatry, M. gulosus occupied sand more often when paired with G. robustum than when alone. G. robustum appears to directly influence the habitat choice of M. gulosus: It seems that M. gulosus is pushed out of the structured habitat that is the preferred habitat of G. robustum. Thus, competition appears to modify the habitat selection of these species when they occur in sympatry. Additionally, the presence of the toadfish was a sufficient stimulus to provoke both M. gulosus and G. robustum to increase their selection for sand (compared to single-species treatments). Distribution patterns of M. gulosus and G. robustum

  16. McGET: A rapid image-based method to determine the morphological characteristics of gravels on the Gobi desert surface

    Science.gov (United States)

    Mu, Yue; Wang, Feng; Zheng, Bangyou; Guo, Wei; Feng, Yiming

    2018-03-01

    The relationship between morphological characteristics (e.g. gravel size, coverage, angularity and orientation) and local geomorphic features (e.g. slope gradient and aspect) of desert has been used to explore the evolution process of Gobi desert. Conventional quantification methods are time-consuming, inefficient and even prove impossible to determine the characteristics of large numbers of gravels. We propose a rapid image-based method to obtain the morphological characteristics of gravels on the Gobi desert surface, which is called the "morphological characteristics gained effectively technique" (McGET). The image of the Gobi desert surface was classified into gravel clusters and background by a machine-learning "classification and regression tree" (CART) algorithm. Then gravel clusters were segmented into individual gravel clasts by separating objects in images using a "watershed segmentation" algorithm. Thirdly, gravel coverage, diameter, aspect ratio and orientation were calculated based on the basic principles of 2D computer graphics. We validated this method with two independent datasets in which the gravel morphological characteristics were obtained from 2728 gravels measured in the field and 7422 gravels measured by manual digitization. Finally, we applied McGET to derive the spatial variation of gravel morphology on the Gobi desert along an alluvial-proluvial fan located in Hami, Xinjiang, China. The validated results show that the mean gravel diameter measured in the field agreed well with that calculated by McGET for large gravels (R2 = 0.89, P < 0.001). Compared to manual digitization, the McGET accuracies for gravel coverage, gravel diameter and aspect ratio were 97%, 83% and 96%, respectively. The orientation distributions calculated were consistent across two different methods. More importantly, McGET significantly shortens the time cost in obtaining gravel morphological characteristics in the field and laboratory. The spatial variation results

  17. A new record of Ratan goby - Ponticola ratan (Nordmann, 1840 (Pisces: Gobiidae in the Black Sea, Romanian coastal waters

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    Daniel Cocan

    2016-11-01

    Full Text Available In August 2015 we managed to capture a specimen of ratan goby (Ponticola ratan in the Romanian coastal waters of the Black Sea, near the locality of Sf. Gheorghe (Tulcea County. This is the 7-th signaling for this species in Romanian coastal waters. The previous 6 specimens were recorded in the period 1960-1993, between Mangalia (Constanţa County and Sulina (Tulcea County. The species was identified by means of meristic characters (number of scales on medial line, number of spiny and soft rays, and morphological particularities (cycloid scales on the nape area and pectoral fin joint. Also, the measurements made, confirmed that the ratio between the head length and total length, which was 33% (TL=8.70 cm vs. Head Length=2.61cm. Another morphological character, specific to this species, is the lower jaw, which exceeds in length the upper jaw. Being a Ponto-Caspian endemite, with low population along the Bulgarian and Romanian coastline, we considered it important to point out this new record. Noting that, being known the trend of sporadic migration of this species, would not be excluded that global warming causes a shift from its normal distribution area, from northern and northeastern (Black Sea to south-west. Therefore, future research may bring more notifications regarding this species in south-western area of the Black Sea

  18. Getting what is served? Feeding ecology influencing parasite-host interactions in invasive round goby Neogobius melanostomus.

    Science.gov (United States)

    Emde, Sebastian; Kochmann, Judith; Kuhn, Thomas; Plath, Martin; Klimpel, Sven

    2014-01-01

    Freshwater ecosystems are increasingly impacted by alien invasive species which have the potential to alter various ecological interactions like predator-prey and host-parasite relationships. Here, we simultaneously examined predator-prey interactions and parasitization patterns of the highly invasive round goby (Neogobius melanostomus) in the rivers Rhine and Main in Germany. A total of 350 N. melanostomus were sampled between June and October 2011. Gut content analysis revealed a broad prey spectrum, partly reflecting temporal and local differences in prey availability. For the major food type (amphipods), species compositions were determined. Amphipod fauna consisted entirely of non-native species and was dominated by Dikerogammarus villosus in the Main and Echinogammarus trichiatus in the Rhine. However, the availability of amphipod species in the field did not reflect their relative abundance in gut contents of N. melanostomus. Only two metazoan parasites, the nematode Raphidascaris acus and the acanthocephalan Pomphorhynchus sp., were isolated from N. melanostomus in all months, whereas unionid glochidia were only detected in June and October in fish from the Main. To analyse infection pathways, we examined 17,356 amphipods and found Pomphorhynchus sp. larvae only in D. villosus in the river Rhine at a prevalence of 0.15%. Dikerogammarus villosus represented the most important amphipod prey for N. melanostomus in both rivers but parasite intensities differed between rivers, suggesting that final hosts (large predatory fishes) may influence host-parasite dynamics of N. melanostomus in its introduced range.

  19. COMPARATIVE CHARACTERISTICS OF MORPHOMETRIC PARAMETERS OF MONKEY GOBY (NEOGOBIUS FLUVIATILIS PALLAS OF FRESH AND SALINE WATER RESERVOIRS IN UKRAINE

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    V. P. Onoprienko

    2014-04-01

    physiological processes. The result of this effect is the difference in weight, size and body parts. To clarify, as our model species was taken Cottus Sandpiper (Neogobius fluviatilis Pallas. The reason for this was the fact that this species, along with other Ponto- Caspian solonovato - freshwater gobies, the International Union for Conservation of Nature classified as species biology are poorly understood and require further research. This fact that deepened interest of ichthyologists in this group of fish, in this regard appeared in the literature as material for the bulls and in Sandpiper. Based on the above, the purpose of this paper is a comparative morphometric parameters characteristic of individuals of this species of fresh and salt water bodies of Ukraine. All this affects the absolute morphometric parameters, which decrease in the direction from sea to the river. However, it should be noted that in rivers with rich feeding grounds sheer size of some individuals close to the size and species of sea Kakhovskoe reservoir. This situation is observed in the Sandpiper Grouse River. Here are some specimens reach a length (TL 118-148 mm and a weight of 15-36 g, Kakhovskoe Reservoir: 106-150 mm 11-38 g, in the Sea of ​​Azov: 115-174 mm 17-58 g. For relative parameters Sandpiper with these reservoirs are more similar, however, for some of them, there are differences. Among the latter is most clearly distinguished the ratio SL / N. This indicator podovzhenist (prohonystist body. As pointed out by VP Mitrofanov (1977, this indicator shows the hydrodynamic qualities of fish: the larger the index, the more active lifestyle is individual. When compared with individuals with a little water and a large stream, in the latter case, individuals are more elongated. This is confirmed by our material: the ratio SL / L for the smallest species of sea of ​​Azov (4.96, slightly more for Kakhovsky reservoir (5.52 and even more for rivers Grouse, Trubizh, Desna, Ros (respectively 5, 86

  20. Mapping of wind energy potential over the Gobi Desert in Northwest China based on multiple sources of data

    Science.gov (United States)

    Li, Li; Wang, Xinyuan; Luo, Lei; Zhao, Yanchuang; Zong, Xin; Bachagha, Nabil

    2018-06-01

    In recent years, wind energy has been a fastgrowing alternative source of electrical power due to its sustainability. In this paper, the wind energy potential over the Gobi Desert in Northwest China is assessed at the patch scale using geographic information systems (GIS). Data on land cover, topography, and administrative boundaries and 11 years (2000‒2010) of wind speed measurements were collected and used to map and estimate the region's wind energy potential. Based on the results, it was found that continuous regions of geographical potential (GeoP) are located in the middle of the research area (RA), with scattered areas of similar GeoP found in other regions. The results also show that the technical potential (TecP) levels are about 1.72‒2.67 times (2.20 times on average) higher than the actual levels. It was found that the GeoP patches can be divided into four classes: unsuitable regions, suitable regions, more suitable regions, and the most suitable regions. The GeoP estimation shows that 0.41 billion kW of wind energy are potentially available in the RA. The suitable regions account for 25.49%, the more suitable regions 24.45%, and the most suitable regions for more than half of the RA. It is also shown that Xinjiang and Gansu are more suitable for wind power development than Ningxia.

  1. La dieta y fauna de endoparásitos del pejesapo Gobiesox marmoratus Jenyns, 1842 (Pisces: Gobiesocidae en el litoral central de Chile están conectadas pero no correlacionadas Feeding habits and endoparasite fauna of the clingfish Gobiesox marmoratus Jenyns, 1842 (Pisces: Gobiesocidae on the central coast of Chile are intertwined, but not correlated

    Directory of Open Access Journals (Sweden)

    M. Cecilia Pardo-Gandarillas

    2004-12-01

    Full Text Available Se documenta una alta similitud en la composición de la fauna parasitaria y de la dieta de 108 ejemplares del pejesapo Gobiesox marmoratus Jenyns, 1842 recolectados de la costa de la zona centro-sur de Chile, desde tres localidades separadas por al menos 400 km de su(s vecina(s. La longitud total de los pejesapos fue similar entre localidades y su parasitofauna estuvo compuesta por 16 taxa de metazoos (incluyendo cinco Myxozoa. En el 38,8 % de los 108 pejesapos se encontraron parásitos, en tanto que en el 32,4 % de los mismos ejemplares había contenido estomacal, en los que se determinaron 37 ítems presa. La aún más baja ocurrencia conjunta de parásitos y presas imposibilitó el uso de parejas de datos parasitarios y dietarios, para evaluar, por ejemplo, si había correlación entre la amplitud dietaria y la riqueza parasitaria. Aunque la composición de la fauna de endoparásitos necesariamente depende de la composición de la dieta de los pejesapos, encontramos muy pocos parásitos en uno de los sitios de estudio. Es decir, las propiedades numéricas de este sistema hospedador-parásito limitaron la posibilidad de hallar asociaciones entre ambos tipos de variables. Tanto la composición de la dieta como de las infracomunidades de parásitos variaban con la ontogenia del huésped. La dieta de los pejesapos juveniles y adultos consistía principalmente de anfípodos, crustáceos decápodos y moluscos en las tres localidades. La similitud de los descriptores numéricos de la dieta y de las infracomunidades (abundancia total, diversidad y riqueza entre las localidades, en parte puede deberse al escaso tamaño corporal máximo alcanzado por G. marmoratus, a la escasa longitud total del tracto digestivo, a las diferencias en las tasas de ingreso y tiempo de residencia de parásitos y presas, al nivel de resolución taxonómica alcanzado en presas y/o parásitos, y al efecto de decidir excluir o no de los análisis a las especies rarasA high

  2. Constraining lithospheric removal and asthenospheric input to melts in Central Asia: A geochemical study of Triassic to Cretaceous magmatic rocks in the Gobi Altai (Mongolia)

    Science.gov (United States)

    Sheldrick, Thomas C.; Barry, Tiffany L.; Van Hinsbergen, Douwe J. J.; Kempton, Pamela D.

    2018-01-01

    Throughout northeast China, eastern and southern Mongolia, and eastern Russia there is widespread Mesozoic intracontinental magmatism. Extensive studies on the Chinese magmatic rocks have suggested lithospheric mantle removal was a driver of the magmatism. The timing, distribution and potential diachroneity of such lithospheric mantle removal remains poorly constrained. Here, we examine successions of Mesozoic lavas and shallow intrusive volcanic plugs from the Gobi Altai in southern Mongolia that appear to be unrelated to regional, relatively small-scale deformation; at the time of magmatism, the area was 200 km from any active margin, or, after its Late Jurassic-Early Cretaceous closure, from the suture of the Mongol-Okhotsk Ocean. 40Ar/39Ar radiometric age data place magmatic events in the Gobi Altai between 220 to 99.2 Ma. This succession overlaps Chinese successions and therefore provides an opportunity to constrain whether Mesozoic lithosphere removal may provide an explanation for the magmatism here too, and if so, when. We show that Triassic to Lower Cretaceous lavas in the Gobi Altai (from Dulaan Bogd, Noyon Uul, Bulgantiin Uul, Jaran Bogd and Tsagaan Tsav) are all light rare-earth element (LREE) and large-ion lithophile element (LILE)-enriched, with negative Nb and Ta anomalies (Nb/La and Ta/La ≤ 1). Geochemical data suggest that these lavas formed by low degrees of partial melting of a metasomatised lithospheric mantle that may have been modified by melts derived from recycled rutile-bearing eclogite. A gradual reduction in the involvement of garnet in the source of these lavas points towards a shallowing of the depth of melting after 125 Ma. By contrast, geochemical and isotope data from the youngest magmatic rocks in the area - 107-99 Ma old volcanic plugs from Tsost Magmatic Field - have OIB-like trace element patterns and are interpreted to have formed by low degrees of partial melting of a garnet-bearing lherzolite mantle source. These rocks did

  3. „A byls v Gobi?“ Glosa k vydané publikaci „Cestou na Východ“ (Praha: Torst 2008

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    Jáchym Topol

    2017-10-01

    Full Text Available Jak jsme s Karlem Cudlínem tuhle knížku dělali? Dobré ani špatné fotky nepotřebují žádné komentáře, na tom jsme se shodli už dávno. Jenže mně to nedalo a musel jsem se ho ptát. Kdys tam byl? Jak velký byly ty ryby? Jak choděj oblíkaný Mongolové? Byls v Gobi? Proč jsi fotil zrovna tohle?

  4. Vigorous dynamics underlie a stable population of the endangered snow leopard Panthera uncia in Tost Mountains, South Gobi, Mongolia.

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    Koustubh Sharma

    Full Text Available Population monitoring programmes and estimation of vital rates are key to understanding the mechanisms of population growth, decline or stability, and are important for effective conservation action. We report, for the first time, the population trends and vital rates of the endangered snow leopard based on camera trapping over four years in the Tost Mountains, South Gobi, Mongolia. We used robust design multi-season mark-recapture analysis to estimate the trends in abundance, sex ratio, survival probability and the probability of temporary emigration and immigration for adult and young snow leopards. The snow leopard population remained constant over most of the study period, with no apparent growth (λ = 1.08+-0.25. Comparison of model results with the "known population" of radio-collared snow leopards suggested high accuracy in our estimates. Although seemingly stable, vigorous underlying dynamics were evident in this population, with the adult sex ratio shifting from being male-biased to female-biased (1.67 to 0.38 males per female during the study. Adult survival probability was 0.82 (SE+-0.08 and that of young was 0.83 (SE+-0.15 and 0.77 (SE +-0.2 respectively, before and after the age of 2 years. Young snow leopards showed a high probability of temporary emigration and immigration (0.6, SE +-0.19 and 0.68, SE +-0.32 before and after the age of 2 years though not the adults (0.02 SE+-0.07. While the current female-bias in the population and the number of cubs born each year seemingly render the study population safe, the vigorous dynamics suggests that the situation can change quickly. The reduction in the proportion of male snow leopards may be indicative of continuing anthropogenic pressures. Our work reiterates the importance of monitoring both the abundance and population dynamics of species for effective conservation.

  5. Behavioral and physiological responses to central administration of corticotropin-releasing factor in the bluebanded goby (Lythrypnus dalli).

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    Solomon-Lane, Tessa K; Grober, Matthew S

    2012-07-16

    Central manipulation of neuromodulators is critical to establishing causal links between brain function and behavioral output. The absence of a rigorous method of evaluating intracerebroventricular (i.c.v.) injection efficacy in small model organisms is one reason why peripheral administration of neuroactive substances is more common. We use the bluebanded goby (Lythrypnus dalli), a small, highly social fish, to 1) validate our method of i.c.v. injection by testing the hypothesis that corticotropin-releasing factor (CRF) elevates ventilation rate (VR) and 2) propose a novel bioassay using basal physiology and behavior during recovery from anesthesia/i.c.v. administration to assess injection efficacy, neuromodulator activity, and procedural confounds. Central CRF administration significantly increased ventilation rate, demonstrating successful delivery of CRF to the brain. There were no significant differences in cortisol among treatments. The injection procedure did, however, decouple the temporal relationship between the initiation of ventilation and time to regain equilibrium present in control fish. Importantly, neither i.c.v. vehicle nor CRF injection affected the initiation of ventilation, disrupted the stereotyped recovery pattern following anesthesia, or initiated an endocrine stress response. Taken together, we suggest that 1) i.c.v. injection can be effectively used to manipulate central levels of CRF in L. dalli and 2) physiological and behavioral recovery from anesthesia may be used to evaluate injection/technique efficacy. We will use these data in future studies as a measure of effective CRF delivery, to allow for appropriate recovery from i.c.v. injection, and to better evaluate independent effects of CRF on social and/or sexual behavior. Copyright © 2012 Elsevier Inc. All rights reserved.

  6. Przewalski’ s Horse ( Equus ferus przewalskii Re-intr oduction in the Great Gobi B Strictly Protected Area: from Species to Ecosystem Conservation

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    P. Kaczensky

    2007-05-01

    Full Text Available The Przewalski’s horse ( Equus ferus przewalskii Po ljakov , 1881, or “T akhi” in Mongolian, became extinct in the wild by the mid 1960’ s. The last recorded sightings of Przewalski’s horses occurred in the Dzungarian Gobi desert in SW Mo ngolia, today’s Great Gobi B Strictly Protected Area (SP A. A re - introduction program was initiated in 1992 and the fi rs t group of captive-born Przewalski’s horses was airlifted to the SPA. Given the logistical challenges associated with such a venture, the initial project focus has been on transport logistics and the well-being of the re-introduced horses. Tod ay, conservation efforts are spread over the entire protected area. Present day ef forts include other mammals, vegetation and the local people. Due to its important symbolic value in Mongolian culture, the Przewalski’ s horse became an important fl agship species for the protected area’s conservation and management.

  7. Seasonal diet pattern of non-native tubenose goby (Proterorhinus semilunaris in a lowland reservoir (Mušov, Czech Republic

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    Adámek Z.

    2010-08-01

    Full Text Available The tubenose goby (Proterorhinus semilunaris is a gobiid species currently extending its area of distribution in Central Europe. The objective of the study was to evaluate the annual pattern of its feeding habits in the newly colonised habitats of the Mušov reservoir on the Dyje River (the Danube basin, Czech Republic with respect to natural food resources. In the reservoir, tubenose goby has established a numerous population, densely colonising stony rip-rap banks. Its diet was exclusively of animal origin with significant dominance of and preference for two food items – chironomid (Chironomidae larvae and waterlouse (Asellus aquaticus, which contributed 40.2 and 27.6%, respectively, to the total food bulk ingested. The index of preponderance for the two items was also very high, amounting to 73.8 and 26.5, respectively. In the annual pattern, a remarkable preference for chironomid larvae was recorded in the summer period whilst waterlouse were consumed predominantly in winter months. The proportion of other food items was rather marginal – only corixids, copepods, ceratopogonids and cladocerans were of certain minor importance with proportions of 5.4, 4.3, 4.1 and 3.9%, respectively. Certain signs of cannibalism were also recorded, with 0.9 and 0.2% of the diet consisting of their own progeny and eggs, respectively.

  8. Emission, transport, and radiative effects of mineral dust from the Taklimakan and Gobi deserts: comparison of measurements and model results

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    Chen, Siyu; Huang, Jianping; Kang, Litai; Wang, Hao; Ma, Xiaojun; He, Yongli; Yuan, Tiangang; Yang, Ben; Huang, Zhongwei; Zhang, Guolong

    2017-02-01

    The Weather Research and Forecasting Model with chemistry (WRF-Chem model) was used to investigate a typical dust storm event that occurred from 18 to 23 March 2010 and swept across almost all of China, Japan, and Korea. The spatial and temporal variations in dust aerosols and the meteorological conditions over East Asia were well reproduced by the WRF-Chem model. The simulation results were used to further investigate the details of processes related to dust emission, long-range transport, and radiative effects of dust aerosols over the Taklimakan Desert (TD) and Gobi Desert (GD). The results indicated that weather conditions, topography, and surface types in dust source regions may influence dust emission, uplift height, and transport at the regional scale. The GD was located in the warm zone in advance of the cold front in this case. Rapidly warming surface temperatures and cold air advection at high levels caused strong instability in the atmosphere, which strengthened the downward momentum transported from the middle and low troposphere and caused strong surface winds. Moreover, the GD is located in a relatively flat, high-altitude region influenced by the confluence of the northern and southern westerly jets. Therefore, the GD dust particles were easily lofted to 4 km and were the primary contributor to the dust concentration over East Asia. In the dust budget analysis, the dust emission flux over the TD was 27.2 ± 4.1 µg m-2 s-1, which was similar to that over the GD (29 ± 3.6 µg m-2 s-1). However, the transport contribution of the TD dust (up to 0.8 ton d-1) to the dust sink was much smaller than that of the GD dust (up to 3.7 ton d-1) because of the complex terrain and the prevailing wind in the TD. Notably, a small amount of the TD dust (PM2.5 dust concentration of approximately 8.7 µg m-3) was lofted to above 5 km and transported over greater distances under the influence of the westerly jets. Moreover, the direct radiative forcing induced by dust

  9. COMPARATIVE CHARACTERISTICS OF MORPHOMETRIC PARAMETERS OF MONKEY GOBY (NEOGOBIUS FLUVIATILIS PALLAS OF FRESH AND SALINE WATER RESERVOIRS IN UKRAINE

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    Onoprienko V.

    2014-04-01

    physiological processes. The result of this effect is the difference in weight, size and body parts. To clarify, as our model species was taken Cottus Sandpiper (Neogobius fluviatilis Pallas. The reason for this was the fact that this species, along with other Ponto- Caspian solonovato - freshwater gobies, the International Union for Conservation of Nature classified as species biology are poorly understood and require further research. This fact that deepened interest of ichthyologists in this group of fish, in this regard appeared in the literature as material for the bulls and in Sandpiper. Based on the above, the purpose of this paper is a comparative morphometric parameters characteristic of individuals of this species of fresh and salt water bodies of Ukraine. All this affects the absolute morphometric parameters, which decrease in the direction from sea to the river. However, it should be noted that in rivers with rich feeding grounds sheer size of some individuals close to the size and species of sea Kakhovskoe reservoir. This situation is observed in the Sandpiper Grouse River. Here are some specimens reach a length (TL 118-148 mm and a weight of 15-36 g, Kakhovskoe Reservoir: 106-150 mm 11-38 g, in the Sea of Azov: 115-174 mm 17-58 g. For relative parameters Sandpiper with these reservoirs are more similar, however, for some of them, there are differences. Among the latter is most clearly distinguished the ratio SL / N. This indicator podovzhenist (prohonystist body. As pointed out by VP Mitrofanov (1977, this indicator shows the hydrodynamic qualities of fish: the larger the index, the more active lifestyle is individual. When compared with individuals with a little water and a large stream, in the latter case, individuals are more elongated. This is confirmed by our material: the ratio SL / L for the smallest species of sea of Azov (4.96, slightly more for Kakhovsky reservoir (5.52 and even more for rivers Grouse, Trubizh, Desna, Ros (respectively 5, 86, 6.22 , 6

  10. Triassic to Cenozoic multi-stage intra-plate deformation focused near the Bogd Fault system, Gobi Altai, Mongolia

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    Douwe J.J. van Hinsbergen

    2015-09-01

    Full Text Available The Gobi Altai region of southern Mongolia has been in the Eurasian plate interior since the mid-Mesozoic, yet has experienced episodic phases of deformation since that time. In this paper, we document field evidence to characterize and date the intra-plate tectonic history of the Gobi Altai region from the Triassic to the present. To this end, we provide detailed mapping of the structure and stratigraphy of the eastern flanks of Mt. Ih Bogd that contains the widest variety of rock-time units in the area. We carry out geochronological analysis of basaltic lavas and basement granite in the area. We demonstrate that a crystalline basement with a 502 ± 8 Ma granitoid (U/Pb underwent two phases of basin formation in the Mesozoic, which we date with new 40Ar/39Ar lava ages of 218.5 ± 1.5, 123.2 ± 0.7 and 124.8 ± 1.2 Ma, respectively. Both phases are linked to deposition of fluvio-lacustrine sediments and trap-like basaltic volcanics, with cumulative thicknesses of 1000–1500 m. Both basins were likely north-facing half-grabens that developed under ∼N–S extension, but were subsequently overthrusted by Paleozoic and older crystalline basement during a less well constrained, but likely mid-Cretaceous phase of N–S shortening and basin inversion. Our results are consistent with recent seismic imaging of rift basins ∼100 km to the NE of the study area where a similar history was reconstructed. The multiple phases of intra-plate deformation appear to have parallel structural trends, most likely due to reactivated Paleozoic basement structures created during the original terrane amalgamation of the Central Asian Orogenic Belt continental crust. This strong basement heterogeneity may predispose it to reactivation, and make it sensitive to changes in the overall stress field of the Eurasian plate driven by forces at its margins and base. Detailed study of Mongolia's multi-stage tectonic history may thus provide a key proxy for the long

  11. Endocrine disrupting chemicals (bisphenol A, 4-nonylphenol, 4-tert-octylphenol) modulate expression of two distinct cytochrome P450 aromatase genes differently in gender types of the hermaphroditic fish Rivulus marmoratus.

    Science.gov (United States)

    Lee, Young-Mi; Seo, Jung Soo; Kim, Il-Chan; Yoon, Yong-Dal; Lee, Jae-Seong

    2006-06-30

    To understand the effect of endocrine-disrupting chemicals (EDCs) on cytochrome P450 aromatase (rm-cyp19) gene expression between gender types in the hermaphroditic fish Rivulus marmoratus, we cloned two distinct rm-cyp19 genes using RT-PCR with degenerative primers, obtained full-length cDNAs using 5'- and 3'-RACE-PCR methods, and completely sequenced them. The brain aromatase (rm-cyp19b) cDNA consisted of 2,124 bp including the open reading frame (ORF), which encoded a putative protein of 505 amino acids. The ovarian aromatase (rm-cyp19a) cDNA consisted of 2,075 bp, including the ORF encoding a putative protein of 516 amino acids. Expression patterns of rm-cyp19b and rm-cyp19a mRNAs were investigated in embryos of different developmental stages and in seven different tissues of adult fish. The rm-cyp19b gene in hermaphrodite and secondary male R. marmoratus was predominantly expressed in the brain, while the rm-cyp19a gene was expressed gender-specifically in the gonad. The expression of rm-cyp19b mRNA increased from stage 1 (2 d post fertilization) to stage 4 (12 d post fertilization) in a developmental stage-dependent manner but steeply decreased in the hatching stage. Compared to the rm-cyp19b gene, the abundance of ovarian aromatase rm-cyp19a transcripts was very low, and its expression was first detected at stage 3 and then decreased gradually to the hatching stage. Alteration of rm-cyp19b and rm-cyp19a gene expression was further analyzed in the brain and gonad by real-time RT-PCR 96 h after EDC exposure in hermaphrodites and secondary males. The brain aromatase rm-cyp19b gene was up-regulated in the brain after 4-nonylphenol (4-NP)-exposure, while the ovarian aromatase rm-cyp19a gene was significantly down-regulated in the gonad. In 300 microg/L 4-tert octylphenol (4-tert-OP), or 600 microg/L bisphenol A-exposed brain and gonad, both rm-cyp19b and rm-cyp19a genes were up-regulated. In the case of secondary males, the rm-cyp19b gene was highly expressed in

  12. Genetic analysis reveals the diversity of larval Gobiidae in a temperate estuary.

    Science.gov (United States)

    Ojaveer, H; Gross, R; Laur, K; Arula, T; Klais, R

    2017-10-01

    Using molecular tools to examine Gobiidae, the second most abundant taxon in ichthyoplankton samples in the Gulf of Riga (Baltic Sea), the sand goby Pomatoschistus minutus was the most abundant taxon (82% of all individuals analysed), the common goby Pomatoschistus microps constituted 12% and the black goby Gobius niger 6%. The spatiotemporal distribution of P. microps and G. niger indicated a preference for habitats closer to the river inlet and their abundances increased slightly towards the end of the sampling period in summer. The species composition was interpreted in the context of the prevailing habitat conditions, characterized by extremely low water transparency, low salinity, limited spread of vegetated area and dominance of sandy-muddy substrata. © 2017 The Fisheries Society of the British Isles.

  13. First report on intersex in invasive round goby Neogobius melanostomus from the Baltic Sea (Gulf of Gdańsk, Poland

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    Tatiana Guellard

    2015-01-01

    Full Text Available This study is the first to report the presence of intersex in invasive round goby Neogobius melanostomus inhabiting the Baltic Sea. The discovery was made in the area of two harbours of the Gulf of Gdańsk (Poland. Macro- and microscopic male gonad analysis revealed the presence of female gametes in testes (testis-ova of single specimens. In addition, a female-like urogenital papilla was observed in one of the intersex fish. These findings might be due to the exposure to estrogenic endocrine disrupting compounds (EDCs however the occurrence of single intersex individuals as a baseline level in investigated population is also possible. In the future, more comprehensive research in the other areas of the Gulf of Gdańsk needs to be carried out in order to determine the extent and to better understand the cause of the observed phenomenon.

  14. Early Engagement of Stakeholders with Individual-Based Modeling Can Inform Research for Improving Invasive Species Management: The Round Goby as a Case Study

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    Emma Samson

    2017-11-01

    Full Text Available Individual-based models (IBMs incorporating realistic representations of key range-front processes such as dispersal can be used as tools to investigate the dynamics of invasive species. Managers can apply insights from these models to take effective action to prevent further spread and prioritize measures preventing establishment of invasive species. We highlight here how early-stage IBMs (constructed under constraints of time and data availability can also play an important role in defining key research priorities for providing key information on the biology of an invasive species in order that subsequent models can provide robust insight into potential management interventions. The round goby, Neogobius melanostomus, is currently spreading through the Baltic Sea, with major negative effects being reported in the wake of its invasion. Together with stakeholders, we parameterize an IBM to investigate the goby's potential spread pattern throughout the Gulf of Gdansk and the Baltic Sea. Model parameters were assigned by integrating information obtained through stakeholder interaction, from scientific literature, or estimated using an inverse modeling approach when not available. IBMs can provide valuable direction to research on invasive species even when there is limited data and/or time available to parameterize/fit them to the degree to which we might aspire in an ideal world. Co-development of models with stakeholders can be used to recognize important invasion patterns, in addition to identifying and estimating unknown environmental parameters, thereby guiding the direction of future research. Well-parameterized and validated models are not required in the earlier stages of the modeling cycle where their main utility is as a tool for thought.

  15. Nine co-localized cytochrome P450 genes of the CYP2N, CYP2AD, and CYP2P gene families in the mangrove killifish Kryptolebias marmoratus genome: Identification and expression in response to B[α]P, BPA, OP, and NP.

    Science.gov (United States)

    Puthumana, Jayesh; Kim, Bo-Mi; Jeong, Chang-Bum; Kim, Duck-Hyun; Kang, Hye-Min; Jung, Jee-Hyun; Kim, Il-Chan; Hwang, Un-Ki; Lee, Jae-Seong

    2017-06-01

    The CYP2 genes are the largest and most diverse cytochrome P450 (CYP) subfamily in vertebrates. We have identified nine co-localized CYP2 genes (∼55kb) in a new cluster in the genome of the highly resilient ecotoxicological fish model Kryptolebias marmoratus. Molecular characterization, temporal and tissue-specific expression pattern, and response to xenobiotics of these genes were examined. The CYP2 gene clusters were characterized and designated CYP2N22-23, CYP2AD12, and CYP2P16-20. Gene synteny analysis confirmed that the cluster in K. marmoratus is similar to that found in other teleost fishes, including zebrafish. A gene duplication event with diverged catalytic function was observed in CYP2AD12. Moreover, a high level of divergence in expression was observed among the co-localized genes. Phylogeny of the cluster suggested an orthologous relationship with similar genes in zebrafish and Japanese medaka. Gene expression analysis showed that CYP2P19 and CYP2N20 were consecutively expressed throughout embryonic development, whereas CYP2P18 was expressed in all adult tissues, suggesting that members of each CYP2 gene family have different physiological roles even though they are located in the same cluster. Among endocrine-disrupting chemicals (EDCs), benzo[α]pyrene (B[α]P) induced expression of CYP2N23, bisphenol A (BPA) induced CYP2P18 and CYP2P19, and 4-octylphenol (OP) induced CYP2AD12, but there was no significant response to 4-nonylphenol (NP), implying differential catalytic roles of the enzyme. In this paper, we identify and characterize a CYP2 gene cluster in the mangrove killifish K. marmoratus with differing catalytic roles toward EDCs. Our findings provide insights on the roles of nine co-localized CYP2 genes and their catalytic functions for better understanding of chemical-biological interactions in fish. Copyright © 2017 Elsevier B.V. All rights reserved.

  16. First field-based observations of δ2H and δ18O values of precipitation and other water bodies in the Mongolian Gobi desert

    Science.gov (United States)

    Burnik Šturm, Martina; Ganbaatar, Oyunsaikhan; Voigt, Christian C.; Kaczensky, Petra

    2017-04-01

    Hydrogen (δ2H) and oxygen (δ18O) isotope values of water are widely used to track the global hydrological cycle and the global δ2H and δ18O patterns of precipitation are increasingly used in studies on animal migration, forensics, food authentication and traceability studies. However, δ2H and δ18O values of precipitation spanning one or more years are available for only a few 100 locations worldwide and for many remote areas such as Mongolia data are still scarce. We obtained the first field-based δ2H and δ18O isotope data of event-based precipitation, rivers and other water bodies in the extreme environment of the Dzungarian Gobi desert in SW Mongolia, covering a period of 16 months (1). Our study area is located over 450 km north-east from the nearest IAEA GNIP station (Fukang station, China) from which it is separated by a mountain range at the international border between China and Mongolia. Isotope values of the collected event-based precipitation showed and extreme range and a high seasonal variability with higher and more variable values in summer and lower in winter. The high variability could not be explained by different origin of air masses alone (i.e. NW polar winds over Russia or westerlies over Central Asia; analyzed using back-trajectory HYSPLIT model), but is likely a result of a combination of different processes affecting the isotope values of precipitation in this area. The calculated field-based local meteoric water line (LMWL, δ2H=(7.42±0.16)δ18O-(23.87±3.27)) showed isotopic characteristics of precipitation in an arid region. We observed a slight discrepancy between the filed based and modelled (Online Isotope in Precipitation Calculator, OIPC) LMWL which highlighted the difficulty of modelling the δ2H and δ18O values for areas with extreme climatic conditions and thus emphasized the importance of collecting long-term field-based data. The collected isotopic data of precipitation and other water bodies provide a basis for future

  17. Southern limits of distribution of the intertidal gobies Chaenogobius annularis and C. gulosus support the existence of a biogeographic boundary in southern Japan (Teleostei, Perciformes, Gobiidae

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    Atsunobu Murase

    2017-12-01

    Full Text Available Understanding the distributional patterns of individual animal groups with respect to coastal topology and the local physical environment provides essential foundational frameworks for marine zoogeography. In the northwestern Pacific waters of Japan, the distributional pattern of some cool-temperate species of marine fishes suggests the existence of a biogeographic boundary corresponding to a long sandy shore on the eastern coast of Kyushu, southern Japan. The existence of this hypothetical biogeographic boundary was tested by mapping the southern distributional limit of two species of cool-temperate intertidal gobies, Chaenogobius annularis and C. gulosus, which are endemic to East Asia and common in rock pools within their range in the Japanese Archipelago. Distribution and abundance were assessed by survey of museum collections from south-east Kyushu (i.e., the entire coasts of Kagoshima and Miyazaki prefectures; and a quantitative survey of the abundance of these gobies in rock pools at various sites around the hypothesized boundary on the eastern coast of Kyushu, including the subtropical Tanega-shima Island. The museum collection survey showed different distribution patterns between the two species: C. annularis was distributed along the entire coasts of south-east Kyushu including subtropical islands, whereas C. gulosus was distributed along these coasts, including one site on a subtropical island, except for an area south of the hypothesized boundary on the eastern coast of Kyushu. The density and occurrence rates of C. annularis in rock pools decreased with latitude, it being absent from a subtropical island, and C. gulosus was not detected from sites south of the hypothesized boundary. The qualitative survey showed that the southernmost records of C. annularis and C. gulosus were the adjacent subtropical islands (Yaku-shima and Tanega-shima islands respectively, although the quantitative survey suggested that their normal range of

  18. Co-expression of antioxidant enzymes with expression of p53, DNA repair, and heat shock protein genes in the gamma ray-irradiated hermaphroditic fish Kryptolebias marmoratus larvae

    Energy Technology Data Exchange (ETDEWEB)

    Rhee, Jae-Sung [Research Institute for Natural Sciences, Hanyang University, Seoul 133-791 (Korea, Republic of); Kim, Bo-Mi; Kim, Ryeo-Ok [Department of Chemistry, College of Natural Sciences, Hanyang University, Seoul 133-791 (Korea, Republic of); Seo, Jung Soo [Pathology Team, National Fisheries Research and Development Institute, Busan 619-902 (Korea, Republic of); Kim, Il-Chan [Division of Life Sciences, Korea Polar Research Institute, Korea Institute of Ocean Science and Technology, Incheon 406-840 (Korea, Republic of); Lee, Young-Mi, E-mail: ymlee70@smu.ac.kr [Department of Green Life Science, College of Convergence, Sangmyung University, Seoul 110-743 (Korea, Republic of); Lee, Jae-Seong, E-mail: jslee2@hanyang.ac.kr [Research Institute for Natural Sciences, Hanyang University, Seoul 133-791 (Korea, Republic of); Department of Chemistry, College of Natural Sciences, Hanyang University, Seoul 133-791 (Korea, Republic of)

    2013-09-15

    Highlights: •Novel identification of DNA repair-related genes in fish. •Investigation of whole expression profiling of DNA repair genes upon gamma radiation. •Analysis of effects of gamma radiation on antioxidant system and cell stress proteins. •Usefulness of verification of pathway-based profiling for mechanistic understanding. -- Abstract: To investigate effects of gamma ray irradiation in the hermaphroditic fish, Kryptolebias marmoratus larvae, we checked expression of p53, DNA repair, and heat shock protein genes with several antioxidant enzyme activities by quantitative real-time RT-PCR and biochemical methods in response to different doses of gamma radiation. As a result, the level of gamma radiation-induced DNA damage was initiated after 4 Gy of radiation, and biochemical and molecular damage became substantial from 8 Gy. In particular, several DNA repair mechanism-related genes were significantly modulated in the 6 Gy gamma radiation-exposed fish larvae, suggesting that upregulation of such DNA repair genes was closely associated with cell survival after gamma irradiation. The mRNA expression of p53 and most hsps was also significantly upregulated at high doses of gamma radiation related to cellular damage. This finding indicates that gamma radiation can induce oxidative stress with associated antioxidant enzyme activities, and linked to modulation of the expression of DNA repair-related genes as one of the defense mechanisms against radiation damage. This study provides a better understanding of the molecular mode of action of defense mechanisms upon gamma radiation in fish larvae.

  19. Use of Water Balance and Tracer-Based Approaches to Monitor Groundwater Recharge in the Hyper-Arid Gobi Desert of Northwestern China

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    Tomohiro Akiyama

    2018-05-01

    Full Text Available The groundwater recharge mechanism in the hyper-arid Gobi Desert of Northwestern China was analyzed using water balance and tracer-based approaches. Investigations of evaporation, soil water content, and their relationships with individual rainfall events were conducted from April to August of 2004. Water sampling of rainwater, groundwater, and surface water was also conducted. During this period, 10 precipitation events with a total amount of 41.5 mm, including a maximum of 28.9 mm, were observed. Evaporation during the period was estimated to be 33.1 mm. Only the soil water, which was derived from the heaviest precipitation, remained in the vadose zone. This is because a dry surface layer, which was formed several days after the heaviest precipitation event, prevented evaporation. Prior to that, the heaviest precipitation rapidly infiltrated without being affected by evaporation. This is corroborated by the isotopic evidence that both the heaviest precipitation and the groundwater retained no trace of significant kinetic evaporation. Estimated δ-values of the remaining soil water based on isotopic fractionation and its mass balance theories also demonstrated no trace of kinetic fractionation in the infiltration process. Moreover, stable isotopic compositions of the heaviest precipitation and the groundwater were very similar. Therefore, we concluded that the high-intensity precipitation, which rapidly infiltrated without any trace of evaporation, was the main source of the groundwater.

  20. Ameliorating effects of goby fish protein hydrolysates on high-fat-high-fructose diet-induced hyperglycemia, oxidative stress and deterioration of kidney function in rats.

    Science.gov (United States)

    Nasri, Rim; Abdelhedi, Ola; Jemil, Ines; Daoued, Ines; Hamden, Khaled; Kallel, Choumous; Elfeki, Abdelfattah; Lamri-Senhadji, Myriem; Boualga, Ahmed; Nasri, Moncef; Karra-Châabouni, Maha

    2015-12-05

    This study investigated the therapeutic potential of undigested goby fish (Zosterisessor ophiocephalus) muscle proteins (UGP) and their hydrolysates on high-fat-high-fructose diet (HFFD)-fed rats. HFFD induced hyperglycemia, manifested by a significant increase in the levels of glucose and glycogen as well as α-amylase activity when compared to normal rats. The administration of GPHs to HFFD-fed rats significantly decreased α-amylase activity and the contents of blood glucose and hepatic glycogen. By contrast, the UGP increased the glucose metabolic disorders in HFFD-fed rats. Furthermore, HFFD-fed rats showed oxidative stress, as evidenced by decreased antioxidant enzyme activities and glutathione (GSH) levels and increased concentration of the lipid peroxidation product malondialdehyde in liver and kidney. Interestingly, the daily gavage of UGP and GPHs improved the redox status in liver and kidney of HFFD-rats by ameliorating or reversing the above-mentioned changes. Moreover, GPHs exhibited a renal protective role by reversing the HFFD-induced decease of uric acid and increase of creatinine levels in serum and preventing some HFFD-induced changes in kidney architecture. The results demonstrate that GPHs contain bioactive peptides that possess significant hypoglycemic and antioxidant properties, and ameliorate renal damage in rats fed hypercaloric diet. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  1. Serum osmolality and ions, and gill Na+/K+-ATPase of spottedtail goby Synechogobius ommaturus (R. in response to acute salinity changes

    Directory of Open Access Journals (Sweden)

    Chun Shui

    2018-03-01

    Full Text Available This study was carried out to determine the effects of abrupt salinity change on osmoregulatory ability of the spottedtail goby Synechogobius ommaturus. 720 juvenile fish (65.3 ± 11.8 g were transferred to 200 L tanks (with 40 juveniles in each tank, in which salinities were abruptly changed from 10 to 20, 30, 40, 50 and freshwater. Survival rate, serum osmolality, electrolytes (Na+, Cl−, and K+ and gill Na+/K+-ATPase (NKA activity were assessed successively in 528 h. Results showed serum osmolality, ion concentrations and gill Na+/K+-ATPase activity increased significantly when fish were transferred to salinity 40 and 50 and all fish in these groups died by the end of the experiment. Serum osmolality, Na+, Cl− and K+ in fish transferred to a salinity of 20, 30 and freshwater were not affected and no mortality was detected. Compared with the control group, a significantly decrease of NKA activity happened in the freshwater group, but the activity in 20 and 30 groups was not affected significantly. The results indicated that S. ommaturus could adapt rapidly and maintain homeostasis in a wide range of salinities (from freshwater to salinity 30 and this species may be suitable for aquaculture in estuarine and coastal areas where rapid salinity fluctuations commonly occur. Keywords: Osmolality, Gill, Na+/K+-ATPase, Synechogobius ommaturus

  2. Mining of biomarker genes from expressed sequence tags and differential display reverse transcriptase-polymerase chain reaction in the self-fertilizing fish, Kryptolebias marmoratus and their expression patterns in response to exposure to an endocrine-disrupting alkylphenol, bisphenol A.

    Science.gov (United States)

    Lee, Young-Mi; Rhee, Jae-Sung; Hwang, Dae-Sik; Kim, Il-Chan; Raisuddin, Sheikh; Lee, Jae-Seong

    2007-06-30

    Expressed sequence tags (ESTs) and differentially expressed cDNAs from the self-fertilizing fish, Kryptolebias marmoratus were mined to develop alternative biomarkers for endocrine-disrupting chemicals (EDCs). 1,577 K. marmoratus cDNA clones were randomly sequenced from the 5'-end. These clones corresponded to 1,518 and 1,519 genes in medaka dbEST and zebrafish dbEST, respectively. Of the matched genes, 197 and 115 genes obtained Unigene IDs in medaka dbEST and zebrafish dbEST, respectively. Many of the annotated genes are potential biomarkers for environmental stresses. In a differential display reverse transcriptase-polymerase chain reaction (DD RT-PCR) study, 56 differential expressed genes were obtained from fish liver exposed to bisphenol A. Of these, 16 genes were identified after BLAST search to GenBank, and the annotated genes were mainly involved in catalytic activity and binding. The expression patterns of these 16 genes were validated by real-time RT-PCR of liver tissue from fish exposed to bisphenol A. Our findings suggest that expression of these 16 genes is modulated by endocrine disrupting chemicals, and therefore that they are potential biomarkers for environmental stress including EDCs exposure.

  3. Application of otolith shape analysis for stock discrimination and species identification of five goby species (Perciformes: Gobiidae) in the northern Chinese coastal waters

    Science.gov (United States)

    Yu, Xin; Cao, Liang; Liu, Jinhu; Zhao, Bo; Shan, Xiujuan; Dou, Shuozeng

    2014-09-01

    We tested the use of otolith shape analysis to discriminate between species and stocks of five goby species ( Ctenotrypauchen chinensis, Odontamblyopus lacepedii, Amblychaeturichthys hexanema, Chaeturichthys stigmatias, and Acanthogobius hasta) found in northern Chinese coastal waters. The five species were well differentiated with high overall classification success using shape indices (83.7%), elliptic Fourier coefficients (98.6%), or the combination of both methods (94.9%). However, shape analysis alone was only moderately successful at discriminating among the four stocks (Liaodong Bay, LD; Bohai Bay, BH; Huanghe (Yellow) River estuary HRE, and Jiaozhou Bay, JZ stocks) of A. hasta (50%-54%) and C. stigmatias (65.7%-75.8%). For these two species, shape analysis was moderately successful at discriminating the HRE or JZ stocks from other stocks, but failed to effectively identify the LD and BH stocks. A large number of otoliths were misclassified between the HRE and JZ stocks, which are geographically well separated. The classification success for stock discrimination was higher using elliptic Fourier coefficients alone (70.2%) or in combination with shape indices (75.8%) than using only shape indices (65.7%) in C. stigmatias whereas there was little difference among the three methods for A. hasta. Our results supported the common belief that otolith shape analysis is generally more effective for interspecific identification than intraspecific discrimination. Moreover, compared with shape indices analysis, Fourier analysis improves classification success during inter- and intra-species discrimination by otolith shape analysis, although this did not necessarily always occur in all fish species.

  4. Reproductive parameters of invasive population of Round goby (Neogobius melanostomus Pallas, 1814) in the Slovak part of the Danube river - preliminary results; Reprodukcne parametre invaznej populacie bycka ciernousteho (Neogobius melanostomus Pallas, 1814) v slovenskom useku Dunaja - predbezne vysledky

    Energy Technology Data Exchange (ETDEWEB)

    Horkova, K [Univerzita Komenskeho v Bratislave, Prirodovedecka fakulta, Katedra ekologie, 84215 Bratislava (Slovakia)

    2012-04-25

    Round goby has a high invasive potential and huge expansive scattering. A suitable reproduction strategy probably helps him in successful colonizing of new territories. This allows him to create offspring also in the environments with constantly changing conditions. The aim of this work was to: (1) Analyze vital signs flexibility of bull populations living in different habitats (Karloveske rameno - less stable habitat, Cunovo - stable habitat). (2) Determine whether the disturbance, which occurred in 2010 on a site Karloveske rameno expressed in reproductive parameters of this population. To achieve the objectives it was necessary to analyze reproductive parameters of the bull individuals from both locations. The population of goby from Karloveske rameno has statistically significantly greater total mean of oocytes and oocyte diameter in different size groups and a higher average value of gonadosomatic index compared with a population of Cunovo. The absolute fertility and relative fertility was lower in Karloveske rameno population despite the fact that a given population had a greater range of values of absolute fertility. (author)

  5. Journal of Genetics | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Genetics; Volume 96; Online resources. Population genetic diversity of marble goby (Oxyeleotris marmoratus)inferred from mitochondrial DNA and microsatellite analysis. CHENG ZHAO XIAOPING ZHU YICHUN GU QINTAO WANG ZECHENG LI SHAOWU YIN. ONLINE RESOURCES Volume 96 ...

  6. Measurement of scattering and absorption properties of dust aerosol in a Gobi farmland region of northwestern China – a potential anthropogenic influence

    Directory of Open Access Journals (Sweden)

    J. Bi

    2017-06-01

    Full Text Available We conducted a comprehensive field campaign to explore the optical characteristics of mineral dust in Dunhuang farmland near the Gobi Desert of northwest China during spring of 2012. The day-to-day and diurnal variations of dust aerosol showed prominent features throughout the experiment, primarily attributable to frequent dust events and local anthropogenic emissions. The overall average mass concentrations of the particulate matter with an aerodynamic diameter less than 10 µm (PM10, light scattering coefficient (σsp, 670, absorption coefficient (σap, 670, and single-scattering albedo (SSA670 were 113 ± 169 µg m−3, 53.3 ± 74.8 Mm−1, 3.2 ± 2.4 Mm−1, and 0.913 ± 0.05, respectively, which were comparable to the background levels in the southern United States but smaller than those in the eastern and other northwestern Chinese cities. The anthropogenic dust produced by agricultural cultivations (e.g., land planning, plowing, and disking exerted a significant superimposed effect on high dust concentrations in Dunhuang farmland prior to the growing season (i.e., from 1 April to 10 May. Strong south valley wind and vertical mixing in daytime scavenged the pollution, and the weak northeast mountain wind and stable inversion layer at night favorably accumulated the air pollutants near the surface. In the afternoon (13:00–18:00 LT, local time, mean SSA670 was 0.945 ± 0.04 predominantly from dust particles, whereas finer particles and lower SSA670 values ( ∼  0.90–0.92 were measured at night, suggesting the potential influence by the mixed dust pollutants. During a typical biomass burning event on 4 April 2012, σap, 670 increased from  ∼  2.0 to 4.75 Mm−1 and SSA670 changed from  ∼  0.90 to  ∼  0.83, implying remarkable modification of aerosol absorptive properties induced by human activities. The findings of this study would help to advance an in

  7. Linking remote-sensing and ecosystem services modeling to support and assess management for regenerative grazing in the South Gobi, Mongolia

    Science.gov (United States)

    Chaplin-Kramer, R.; Kowal, V. A.; Sharp, R.

    2017-12-01

    Managing and monitoring supply chain sustainability is a major challenge and opportunity for business, especially in rangelands, heavily managed and often degraded natural systems that provide significant resources and raw materials for production. One of the largest and most threatened rangeland systems in the world is in Mongolia, which has seen a rapid rise in grazing pressure due to increasing global demand for cashmere along with privatization of a formerly government-run livestock industry. A new opportunity is emerging for remote-sensing to improve the management decisions of the producers and their incentive-setters, leading to a more sustainable rangeland system and better outcomes for biodiversity and people in this unique and imperiled landscape. Oyu Tolgoi (OT), the Mongolian subsidiary of the mining company Rio Tinto, in cooperation with Kering, an apparel conglomerate that sources cashmere from the region, are providing financial incentives to improve grazing patterns through a Sustainable Cashmere program, in order to restore the degraded rangeland ecosystem in the Gobi desert region. We present a framework and approach for predicting the effect of changing grazing practices on biodiversity and ecosystem services, which we are developing into decision-support tools for OT, Kering, and their local partner Wildlife Conservation Society to quantify the impacts of their programs and where these interventions will have greatest benefit. Our approach integrates remote-sensing and ecosystem modeling to scale up field monitoring data and forecast future impacts. Our rangeland production model, based on the soil-vegetation model CENTURY and the livestock model GRAZPLAN, predicts biomass production and plant species composition changes, and can feed into ecosystem services models such as soil retention and water regulation in the InVEST (Integrated Valuation of Ecosystem Services and Trade-offs) software suite. This presents a significant advance in ecosystem

  8. Morphological selection and the evaluation of potential tradeoffs between escape from predators and the climbing of waterfalls in the Hawaiian stream goby Sicyopterus stimpsoni.

    Science.gov (United States)

    Blob, Richard W; Kawano, Sandy M; Moody, Kristine N; Bridges, William C; Maie, Takashi; Ptacek, Margaret B; Julius, Matthew L; Schoenfuss, Heiko L

    2010-12-01

    Environmental pressures may vary over the geographic range of a species, exposing subpopulations to divergent functional demands. How does exposure to competing demands shape the morphology of species and influence the divergence of populations? We explored these questions by performing selection experiments on juveniles of the Hawaiian goby Sicyopterus stimpsoni, an amphidromous fish that exhibits morphological differences across portions of its geographic range where different environmental pressures predominate. Juvenile S. stimpsoni face two primary and potentially opposing selective pressures on body shape as they return from the ocean to freshwater streams on islands: (1) avoiding predators in the lower reaches of a stream; and (2) climbing waterfalls to reach the habitats occupied by adults. These pressures differ in importance across the Hawaiian Islands. On the youngest island, Hawai'i, waterfalls are close to shore, thereby minimizing exposure to predators and placing a premium on climbing performance. In contrast, on the oldest major island, Kaua'i, waterfalls have eroded further inland, lengthening the exposure of juveniles to predators before migrating juveniles begin climbing. Both juvenile and adult fish show differences in body shape between these islands that would be predicted to improve evasion of predators by fish from Kaua'i (e.g., taller bodies that improve thrust) and climbing performance for fish from Hawai'i (e.g., narrower bodies that reduce drag), matching the prevailing environmental demand on each island. To evaluate how competing selection pressures and functional tradeoffs contribute to the divergence in body shape observed in S. stimpsoni, we compared selection imposed on juvenile body shape by (1) predation by the native fish Eleotris sandwicensis versus (2) climbing an artificial waterfall (∼100 body lengths). Some variables showed opposing patterns of selection that matched predictions: for example, survivors of predation had

  9. The circular Uneged Uul structure (East Gobi Basin, Mongolia) - Geomorphic and structural evidence for meteorite impact into an unconsolidated coarse-clastic target?

    Science.gov (United States)

    Schmieder, Martin; Seyfried, Hartmut; Gerel, Ochir

    2013-03-01

    The Uneged Uul structure is a ˜10 km circular, complex, multi-ridged domal feature in the Unegt subbasin of the East Gobi Basin, southeastern Mongolia. As revealed by remote sensing and recent field reconnaissance, the central part of the Uneged Uul structure comprises a complex central peak of outward-radiating curved ridges, composed of stratigraphically uplifted greenschist-facies basement schists, surrounded by an annular moat. The most prominent feature of the structure is a central annular ridge ˜3 km in diameter composed of pebble-boulder conglomerates and gravels of the Upper Jurassic Sharilyn Formation, surrounded by three outer domal ridges composed of Lower Cretaceous conglomeratic sandstones and gypsum clays. Jurassic conglomerates forming the main part of the central annular ridge show effects of severe internal deformation. The original population of pebbles, cobbles and boulders appears moderately displaced and mostly broken but nowhere aligned along shear planes or foliated. Primary sedimentary features, such as cross-lamination or imbrication, have been obliterated. We explain this penetrative brecciation as a result of dissipative shearing caused by a strong and rapid singular event that in magnitude was beyond the range of the common crustal tectonics recorded elsewhere in this region. Disrupted and chaotically distributed conglomeratic sandstone beds in the central annular ridge dip in highly variable directions on a local scale but show an apparent SE-NW trend of bedding plane alignment. Further outside, the tilted and uplifted Upper Jurassic to Lower Cretaceous strata of the domal area are overlain by the flat-lying Upper Cretaceous, which stratigraphically constrains the timing of deformation at the Uneged Uul structure to most likely the Early Cretaceous. Endogenic formation models, such as magmatism and salt, gypsum, or mud diapirism, fail to explain the nature of the Uneged Uul structure. The Uneged Uul structure bears a set of

  10. Impact of Gobi desert dust on aerosol chemistry of Xi'an, inland China during spring 2009: differences in composition and size distribution between the urban ground surface and the mountain atmosphere

    Directory of Open Access Journals (Sweden)

    G. H. Wang

    2013-01-01

    Full Text Available Composition and size distribution of atmospheric aerosols from Xi'an city (~400 m, altitude in inland China during the spring of 2009 including a massive dust event on 24 April were measured and compared with a parallel measurement at the summit (2060 m, altitude of Mt. Hua, an alpine site nearby Xi'an. EC (elemental carbon, OC (organic carbon and major ions in the city were 2–22 times higher than those on the mountaintop during the whole sampling period. Compared to that in the non-dust period a sharp increase in OC was observed at both sites during the dust period, which was mainly caused by an input of biogenic organics from the Gobi desert. However, adsorption/heterogeneous reaction of gaseous organics with dust was another important source of OC in the urban, contributing 22% of OC in the dust event. In contrast to the mountain atmosphere where fine particles were less acidic when dust was present, the urban fine particles became more acidic in the dust event than in the non-dust event, mainly due to enhanced heterogeneous formation of nitrate and diluted NH3. Cl and NO3 in the urban air during the dust event significantly shifted toward coarse particles. Such redistributions were further pronounced on the mountaintop when dust was present, resulting in both ions almost entirely staying in coarse particles. On the contrary, no significant spatial difference in size distribution of SO42− was found between the urban ground surface and the mountain atmosphere, which dominated in the fine mode (<2.1 μm during the nonevent and comparably distributed in the fine (<2.1 μm and coarse (>2.1 μm modes during the dust event.

  11. Hypoxia increases the risk of egg predation in a nest-guarding fish

    DEFF Research Database (Denmark)

    Olsson, Karin; Kvarnemo, Charlotta; Andrén, Maria Norevik

    2016-01-01

    For fish with parental care, a nest should meet both the oxygenation needs of the eggs and help protect them against predators. While a small nest opening facilitates the latter, it impedes the former and vice versa. We investigated how the presence of potential egg predators in the form of shore...... in high oxygen reduced fanning, males in low oxygen did not. Filial cannibalism was unaffected by treatment. Sand gobies thus prioritize egg ventilation over the protection afforded by small nest openings under hypoxia and adopt defensive behaviour to avert predator attention, even though this does...... crabs Carcinus maenas affects nest building, egg fanning, defensive displays and filial cannibalism of egg-guarding male sand gobies Pomatoschistus minutus under two levels of dissolved oxygen. In the high oxygen treatment, males retained their nest opening size in the presence of crabs, while males...

  12. Food conditions of the sand goby

    NARCIS (Netherlands)

    Freitas, V.; Lika, K.; Witte, J.IJ.; van der Veer, H.W.

    2011-01-01

    Several epibenthic species aggregate in large numbers in shallow waters during summer, feeding on the available benthic meio- and macrofauna. Whether this concentration leads to periods of food limitation affecting habitat quality for some of these species is not clear at present. In this study we

  13. História natural dos amborés e peixes-macaco (Actinopterygii, Blennioidei, Gobioidei do Parque Nacional Marinho do Arquipélago de Fernando de Noronha, sob um enfoque comportamental Natural history focus blennies and gobis behaviour (Actinopterygii, Blennioidei, Gobioidei from Fernando de Noronha Archipelago

    Directory of Open Access Journals (Sweden)

    Liana de F. Mendes

    2006-09-01

    Full Text Available Os amborês e peixes-macaco, como são popularmente conhecidos gobiídeos e bleniídeos, são elementos dominantes da fauna de pequenos peixes bentônicos e litorâneos que habitam recifes tropicais, compondo grande parte da alta diversidade das espécies de pequeno porte encontrada no Atlântico ocidental. O estudo da distribuição e história natural dos gobióides e blenióides de Fernando de Noronha foi desenvolvido através de observações de campo. Além da descrição dos hábitats preferenciais foram abordados aspectos sociais tais como, habitat preferencial, interações intra- e interespecíficas, comportamento domiciliar e territorial, e comportamento reprodutivo. A maioria das espécies em foco apresenta distribuição principalmente litorânea, são gregárias, com áreas domiciliares relativamente pequenas em torno de 2 x 2 m², pouco agressivas, tendo sido ocasionalmente registradas curtas perseguições intra- e interespecíficas. A baixa agressividade registrada, em comparação com outros peixes é provavelmente associada à adaptação à ocupação de pequenas áreas, como é o caso das poças de marés, pois um grande número de interações agressivas representaria um gasto de energia desnecessário. No geral, as espécies possuem coloração críptica, associada à evitação de predadores. Apenas nestas épocas de reprodução foi observada a intensificação da agressividade, com comportamento territorial - defesa de território incluindo mordidas e perseguições.The gobis and blenis (Gobiidae and Bleniidae are the most important group of small benthic littoral fishes in tropical reefs, representing most of the high number of small fish species found in Western Atlantic. The natural history of gobiid and bleniid fish from Fernando de Noronha was assessed by means observation sessions using both snorkelling and scuba diving. Most of these observations were aimed at social behaviour, such as intra and interespecific

  14. Noise can affect acoustic communication and subsequent spawning success in fish.

    Science.gov (United States)

    de Jong, Karen; Amorim, M Clara P; Fonseca, Paulo J; Fox, Clive J; Heubel, Katja U

    2018-06-01

    There are substantial concerns that increasing levels of anthropogenic noise in the oceans may impact aquatic animals. Noise can affect animals physically, physiologically and behaviourally, but one of the most obvious effects is interference with acoustic communication. Acoustic communication often plays a crucial role in reproductive interactions and over 800 species of fish have been found to communicate acoustically. There is very little data on whether noise affects reproduction in aquatic animals, and none in relation to acoustic communication. In this study we tested the effect of continuous noise on courtship behaviour in two closely-related marine fishes: the two-spotted goby (Gobiusculus flavescens) and the painted goby (Pomatoschistus pictus) in aquarium experiments. Both species use visual and acoustic signals during courtship. In the two-spotted goby we used a repeated-measures design testing the same individuals in the noise and the control treatment, in alternating order. For the painted goby we allowed females to spawn, precluding a repeated-measures design, but permitting a test of the effect of noise on female spawning decisions. Males of both species reduced acoustic courtship, but only painted gobies also showed less visual courtship in the noise treatment compared to the control. Female painted gobies were less likely to spawn in the noise treatment. Thus, our results provide experimental evidence for negative effects of noise on acoustic communication and spawning success. Spawning is a crucial component of reproduction. Therefore, even though laboratory results should not be extrapolated directly to field populations, our results suggest that reproductive success may be sensitive to noise pollution, potentially reducing fitness. Copyright © 2017 Elsevier Ltd. All rights reserved.

  15. Small-sized euryhaline fish as intermediate hosts of the digenetic trematode Cryptocotyle concavum

    Science.gov (United States)

    Zander, C. D.; Kollra, H.-G.; Antholz, B.; Meyer, W.; Westphal, D.

    1984-03-01

    Cercariae of the trematode Cryptocotyle concavum, which encyst in skin and/or kidney of sticklebacks and gobies, were studied in the Schlei Fjord (western Baltic Sea). Mean incidence of dermal cysts was 48 % in Gasterosteus aculeatus and 37 % in Pungitius pungitius. No cysts were found in the kidneys of sticklebacks. While 97 % of Pomatoschistus microps had encysted metacercariae in the kidneys, only 2 % had cysts in the skin. Pomatoschistus minutus, however, showed hardly any cyst infestation of either skin or kidney. In P. microps the intensity of infestation by metacercariae was frequently more than 50 cysts; in contrast, sticklebacks rarely exhibited more than 5 dermal cysts. Infested fish were larger than 10 mm in total length, the incidence rate increasing with growth. Parasitic infestation depends on ambient salinity: C. concavum was not found at salinities below 4 ‰. In contrast to the high incidence in fish, the first hosts — the snails Hydrobia stagnalis and H. neglecta — showed remarkably low infection rates (3 to 5 %). The findings reported are related to the distribution of C. concavum, the mode of life of infested fish, the feeding habits of the final hosts and the infestation of P. microps by other parasites. Evidently, P. microps represents an optimal second host for C. concavum.

  16. Body size mediates social and environmental effects on nest building behaviour in a fish with paternal care.

    Science.gov (United States)

    Lehtonen, Topi K; Lindström, Kai; Wong, Bob B M

    2015-07-01

    Body size, social setting, and the physical environment can all influence reproductive behaviours, but their interactions are not well understood. Here, we investigated how male body size, male-male competition, and water turbidity influence nest-building behaviour in the sand goby (Pomatoschistus minutus), a marine fish with exclusive paternal care. We found that environmental and social factors affected the nest characteristics of small and large males differently. In particular, association between male size and the level of nest elaboration (i.e. the amount of sand piled on top of the nest) was positive only under clear water conditions. Similarly, male size and nest entrance size were positively associated only in the absence of competition. Such interactions may, in turn, help to explain the persistence of variation in reproductive behaviours, which-due to their importance in offspring survival-are otherwise expected to be under strong balancing selection.

  17. Growth and reproduction of the pelagic goby Sufflogobius ...

    African Journals Online (AJOL)

    Two batches of yolked oocytes were present in the ovaries and the maximum ... 2 000 eggs in females 5.0–5.5cm long to about 10 000 in a female 9.8cm long. The mean fecundity was 842 ± 189 eggs per gramme of ovary-free body weight.

  18. A NEW FRESHWATER GOBY (TELEOSTEI: GOBIIDAE) FROM THE ...

    African Journals Online (AJOL)

    497. JUDB, R. A. 1967. Freshwater fishes of southern Africa. Cape Town: Balkema. KOUMANS, F. P. 1931. A preliminary revision of the genera of the gobioidfishes with united ventral fins. N. V. Lisse. (Netherlands) 1-174: Drukkerij, Imperator. R.

  19. Neurohypophysial Hormones Regulate Amphibious Behaviour in the Mudskipper Goby.

    Science.gov (United States)

    Sakamoto, Tatsuya; Nishiyama, Yudai; Ikeda, Aoi; Takahashi, Hideya; Hyodo, Susumu; Kagawa, Nao; Sakamoto, Hirotaka

    2015-01-01

    The neurohypophysial hormones, arginine vasotocin and isotocin, regulate both hydromineral balance and social behaviors in fish. In the amphibious mudskipper, Periophthalmus modestus, we previously found arginine-vasotocin-specific regulation of aggressive behavior, including migration of the submissive subordinate into water. This migration also implies the need for adaptation to dehydration. Here, we examined the effects of arginine vasotocin and isotocin administration on the amphibious behavior of individual mudskippers in vivo. The mudskippers remained in the water for an increased period of time after 1-8 h of intracerebroventricular (ICV) injection with 500 pg/g arginine vasotocin or isotocin. The 'frequency of migration' was decreased after ICV injection of arginine vasotocin or isotocin, reflecting a tendency to remain in the water. ICV injections of isotocin receptor antagonist with arginine vasotocin or isotocin inhibited all of these hormonal effects. In animals kept out of water, mRNA expression of brain arginine vasotocin and isotocin precursors increased 3- and 1.5-fold, respectively. Given the relatively wide distribution of arginine vasotocin fibres throughout the mudskipper brain, induction of arginine vasotocin and isotocin under terrestrial conditions may be involved also in the preference for an aquatic habitat as ligands for brain isotocin receptors.

  20. Neurohypophysial Hormones Regulate Amphibious Behaviour in the Mudskipper Goby.

    Directory of Open Access Journals (Sweden)

    Tatsuya Sakamoto

    Full Text Available The neurohypophysial hormones, arginine vasotocin and isotocin, regulate both hydromineral balance and social behaviors in fish. In the amphibious mudskipper, Periophthalmus modestus, we previously found arginine-vasotocin-specific regulation of aggressive behavior, including migration of the submissive subordinate into water. This migration also implies the need for adaptation to dehydration. Here, we examined the effects of arginine vasotocin and isotocin administration on the amphibious behavior of individual mudskippers in vivo. The mudskippers remained in the water for an increased period of time after 1-8 h of intracerebroventricular (ICV injection with 500 pg/g arginine vasotocin or isotocin. The 'frequency of migration' was decreased after ICV injection of arginine vasotocin or isotocin, reflecting a tendency to remain in the water. ICV injections of isotocin receptor antagonist with arginine vasotocin or isotocin inhibited all of these hormonal effects. In animals kept out of water, mRNA expression of brain arginine vasotocin and isotocin precursors increased 3- and 1.5-fold, respectively. Given the relatively wide distribution of arginine vasotocin fibres throughout the mudskipper brain, induction of arginine vasotocin and isotocin under terrestrial conditions may be involved also in the preference for an aquatic habitat as ligands for brain isotocin receptors.

  1. Daily feeding periodicity of the intertidal goby Caffrogobius caffer

    African Journals Online (AJOL)

    en laagwater. Voedsel is dwarsdeur die dag ingeneem en daar is 'n effense neiging tot hoogtepunte in die voedingsaktiwiteit gedurende skemertye. S.·Afr. Tydskr. ... These two phenomena, tide and light intensi- ty, might be expected to have an effect on the feeding periodicity of C. coffer. Twenty-four-hour collections were ...

  2. Paleolakes in the Gobi region of southern Mongolia

    Science.gov (United States)

    Lehmkuhl, Frank; Grunert, Jörg; Hülle, Daniela; Batkhishig, Ochirbat; Stauch, Georg

    2018-01-01

    Numerous lakes and remnants of paleolakes exist in western and southern Mongolia. For six basins in the area, detailed geomorphological maps were compiled, based on extensive field studies and remote sensing datasets. Several phases of high and low lake levels were reconstructed and dated by radiocarbon and optically stimulated luminescence. During the marine isotope stage (MIS) 6 lakes in southern and western Mongolia mostly disappeared. In contrast, large paleolakes existed during the last interglacial (MIS 5e) and lasted probably until the beginning of the last glacial. These huge lakes were caused by a strong East Asian summer monsoon, which reached southern and even western Mongolia. During the MIS 3 the monsoon was considerably weaker and most of the lakes were relatively small or even disappeared. Higher lake levels of this period were only recorded at the Orog Nuur. However, at this time the lake was fed by glacial melt water from the Khangai Mountains. The MIS 2 was again a very dry period. The previously supposed phase of synchronous high lake levels and glaciations in southern and western Mongolia is not supported by the data presented here. During the Holocene, lakes in the western and southern part of the study area evolved differently. Early Holocene high lake levels were reconstructed for the western lakes, while most of the southern lakes had highest lake levels in the mid-Holocene. These differences can be attributed to different moisture bearing atmospheric systems. In the late Holocene lake levels were generally low and in the last 50 years most lakes completely disappeared due to a strong human usage of the water resources.

  3. Dual impact of temperature on growth and mortality of marine fish larvae in a shallow estuarine habitat

    Science.gov (United States)

    Arula, Timo; Laur, Kerli; Simm, Mart; Ojaveer, Henn

    2015-12-01

    High individual growth and mortality rates of herring Clupea harengus membras and goby Pomatoschistus spp. larvae were observed in the estuarine habitat of the Gulf of Riga, Baltic Sea. Both instantaneous mortality (0.76-1.05) as well as growth rate (0.41-0.82 mm day-1) of larval herring were amongst highest observed elsewhere previously. Mortality rates of goby larvae were also high (0.57-1.05), while first ever data on growth rates were provided in this study (0.23-0.35 mm day-1). Our study also evidenced that higher growth rate of marine fish larvae did not result in lower mortalities. We suggest that high growth and mortality rates primarily resulted from a rapidly increasing and high (>18 °C) water temperature that masked potential food-web effects. The explanation for observed patterns lies in the interactive manner temperature contributed: i) facilitating prey production, which supported high growth rate and decreased mortalities; ii) exceeding physiological thermal optimum of larvae, which resulted in decreased growth rate and generally high mortalities. Our investigation suggests that the projected climate warming may have significant effect on early life history stages of the dominating marine fish species inhabiting shallow estuaries.

  4. Preliminary Insight into Winter Native Fish Assemblages in Guadiana Estuary Salt Marshes Coping with Environmental Variability and Non-Indigenous Fish Introduction

    Directory of Open Access Journals (Sweden)

    Renata Gonçalves

    2017-10-01

    Full Text Available This work aims to undertake a preliminary characterization of winter fish assemblages in the salt marsh areas of Guadiana lower estuary (South-East Portugal and discusses the potential risks of habitat dominance by a non-indigenous species (NIS. To this effect, six field campaigns were carried out in four sampling sites during winter season targeting the collection of fish species. A total of 48 samples were collected. Individuals from seven different taxa (marine and estuarine were collected, although the assemblage was dominated by two estuarine species—the native Pomatoschistus sp. (goby and the NIS Fundulus heteroclitus (mummichog. Goby was the most abundant taxa in the majority of salt marsh habitats, except for one specific, marsh pool, where extreme environmental conditions were registered, namely high temperature and salinity. Such conditions may have boosted the intrusion of mummichog in this area. This species is well adapted to a wide range of abiotic factors enabling them to colonize habitats where no predators inhabit. Impacts of mummichog introduction in the Guadiana salt marsh area are still unpredictable since this is the first time they have been recorded in such high density. Nevertheless, in scenarios of increased anthropogenic pressure and, consequently, habitat degradation, there is a potential risk of mummichog spreading to other habitats and therefore competing for space and food resources with native species.

  5. Morphological differences in the skin of marble trout Salmo marmoratus and of brown trout Salmo trutta

    Czech Academy of Sciences Publication Activity Database

    Sivka, U.; Halačka, Karel; Sušnik Bajec, S.

    2012-01-01

    Roč. 50, č. 2 (2012), s. 255-262 ISSN 0239-8508 R&D Projects: GA AV ČR 1QS500450513 Institutional support: RVO:68081766 Keywords : melanophore * epidermis * dermis * colour pattern * pigmentation Subject RIV: EG - Zoology Impact factor: 1.101, year: 2012 http://czasopisma.viamedica.pl/fhc/article/view/14750

  6. Status Review of the Marbled Murrelet (Brachyramphus marmoratus) in Alaska and British Columbia

    Science.gov (United States)

    2006-01-01

    provincial government for a range of values including wildlife, biodiversity, soils , visual quality, water, and fish, all of which may contribute in part to...murrelet at or near its nest site on Storey Island in Prince William Sound. Based on damaged eggshells remaining in failed nests, Naslund and others...Egg or eggshell fragments found 7 2 0 1 Records where information on forest cover was available General cover type Area was forested 4 5 1 9 Not

  7. Changes in benthic fish assemblages as a consequence of coastal works in a coastal lagoon: The Mar Menor (Spain, Western Mediterranean).

    Science.gov (United States)

    Pérez-Ruzafa, A; García-Charton, J A; Barcala, E; Marcos, C

    2006-01-01

    The benthic fish assemblage of the Mar Menor consisted of 37 species. Dominant species are: Gobius cobitis, Lipophrys pavo and Tripterygion tripteronotus on infralittoral rocks; Pomatoschistus marmoratus, Callionymus pussillus, Callionymus risso and Solea vulgaris on sandy bottoms and Gobius niger, Syngnathus abaster, Hippocampus ramulosus and Symphodus cinereus on Cymodocea nodosa-Caulerpa prolifera mixed beds. From 1985 to 1989 tourist development has led to the creation of new beaches and the installation of artificial rocky structures for retaining sediments. Dredging for the extraction of sand and subsequent pumping altered sediment characteristics causing a real stress leading to the substitution of typical sandy bottoms communities with Cymodocea nodosa by Caulerpa prolifera communities on mud. Soft bottom fish assemblages responded to changes in vegetation cover and substratum characteristics mainly changing the species composition, while artificial hard substrata contain a similar fish community than natural ones, harbouring even richer and more diverse assemblages. This positive effect of breakwaters should not obscure their likely negative effects on hydrodynamics and the subsequent changes of sediment quality and vegetation cover on the breakwaters' area of influence.

  8. Hormonal regulation of colour change in eyes of a cryptic fish

    Directory of Open Access Journals (Sweden)

    Helen Nilsson Sköld

    2015-01-01

    Full Text Available Colour change of the skin in lower vertebrates such as fish has been a subject of great scientific and public interest. However, colour change also takes place in eyes of fish and while an increasing amount of data indicates its importance in behaviour, very little is known about its regulation. Here, we report that both eye and skin coloration change in response to white to black background adaptation in live sand goby Pomatoschistus minutes, a bentic marine fish. Through in vitro experiments, we show that noradrenaline and melanocyte concentrating hormone (MCH treatments cause aggregation of pigment organelles in the eye chromatophores. Daylight had no aggregating effect. Combining forskolin to elevate intracellular cyclic adenosine monophosphate (cAMP with MCH resulted in complete pigment dispersal and darkening of the eyes, whereas combining prolactin, adrenocorticotrophic hormone (ACTH or melanocyte stimulating hormone (α-MSH with MCH resulted in more yellow and red eyes. ACTH and MSH also induced dispersal in the melanophores, resulting in overall darker eyes. By comparing analysis of eyes, skin and peritoneum, we conclude that the regulation pattern is similar between these different tissues in this species which is relevant for the cryptic life strategy of this species. With the exception of ACTH which resulted in most prominent melanophore pigment dispersal in the eyes, all other treatments provided similar results between tissue types. To our knowledge, this is the first study that has directly analysed hormonal regulation of physiological colour change in eyes of fish.

  9. Infections may select for filial cannibalism by impacting egg survival in interactions with water salinity and egg density.

    Science.gov (United States)

    Lehtonen, Topi K; Kvarnemo, Charlotta

    2015-07-01

    In aquatic environments, externally developing eggs are in constant contact with the surrounding water, highlighting the significance of water parameters and pathogens for egg survival. In this study we tested the impact of water salinity, egg density and infection potential of the environment on egg viability in the sand goby (Pomatoschistus minutus), a small fish that exhibits paternal egg care and has a marine origin, but which in the Baltic Sea lives in brackish water. To manipulate the infection potential of the environment, we added either a Saprolegnia infection vector into UV-filtered water or a fungicide into natural Baltic Sea water. Saprolegnia are widely spread water moulds that are a key cause of egg mortality in aquatic organisms in fresh- and brackish water. We found that increased water salinity indeed decreased the egg infection rate and had a positive effect on egg viability, while high egg density tended to have the opposite effect. However, the different factors influenced egg viability interactively, with a higher egg density having negative effects at low, but not in high, salinity. Thus, the challenges facing marine organisms adapting to lower salinity levels can be amplified by Saprolegnia infections that reduce egg survival in interaction with other environmental factors. Our results support the hypothesis that suppressing egg infections is an important aspect of parental care that can select for filial cannibalism, a common but poorly understood behaviour, especially in fish with parental care.

  10. Multi-scale analyses of nest site selection and fledging success by marbled murrelets (Brachyramphus marmoratus) in British Columbia

    OpenAIRE

    Silvergieter, Michael Paul

    2009-01-01

    I studied nesting habitat selection and fledging success by marbled murrelets, a seabird that nests in old-growth forests of high economic value, at two regions of southwestern British Columbia. At Clayoquot Sound, habitat occurs in larger stands, and murrelets selected steeper slopes and patches with more platform trees, and shorter trees, than at random sites. At Desolation Sound, where smaller forest stands predominate, patch scale variables were less important; increased canopy complexity...

  11. Purification and Pore Forming Activity of Two Hydrophobic Polypeptides from the Secretion of the Red Sea Moses Sole (Pardachirus marmoratus)

    Science.gov (United States)

    1986-11-01

    Uppsala, Sweden. Ovalbumin, bovine albumin fractio n V, soybean lecithin , sodium cnolate, gramicidin D and Dowex 50 x 8 (50-100 mesh) were obtained from...A-,.ino acid analysis 50 ug duplIcate samples of PXI and PXII, from reverse phase HPLC, were dissolved in 0.4 ml of 6 N HCI and hydrolyzed ocr 24 hr

  12. Fish fauna recovery in a newly re-flooded Mediterranean coastal lagoon

    Science.gov (United States)

    Koutrakis, Emmanuil; Sylaios, Georgios; Kamidis, Nikolaos; Markou, Dimitrios; Sapounidis, Argyris

    2009-08-01

    Drana Lagoon, located at the NW site of Evros River Delta, was drained in 1987 and re-flooded in 2004 within the framework of an integrated wetland restoration project. This study presents the results of a monitoring program of the lagoon's oceanographic, water quality and fish fauna characteristics, during the pre- and post-restoration period. Results depict the presence of high salinity water (up to 41) due to seawater intrusion, strong evaporation in its interior and inadequate freshwater inflows. Overall, nutrient levels were low depicting local changes. Tidal variability at the mouth was approximately 0.2 m, producing high velocity tidal currents (up to 0.75 m/s). Eleven fish fauna species were collected; seven species were caught in both the inlet channel and the lagoon during the pre-restoration period and nine species in the post-restoration period. Atherina boyeri (37.6%) and Pomatoschistus marmoratus (31.7%) dominated the lagoon during the post-restoration period. Most of the A. boyeri specimens (88.5%) were caught inside the lagoon, while P. marmoratus had an almost equal distribution in the inlet channel and the lagoon (56.3% and 43.7% respectively). The presence of species of the Mugilidae family (5.2% total average catches after lagoon re-flooding) was mainly in the inlet channel (12.6% of the average catches) and not inside the lagoon (only 1.3% of the average catches). The small number of fish species inhabiting the lagoon might be the result of the recent restoration or it could be related with the increased water flow observed at the lagoon mouth during the flood and ebb tidal phases, and also in the presence of a smooth bank in the concrete waterspout that connects the entrance channel with the lagoon. The limited presence of the Mugilidae juveniles inside the lagoon could be related to the prevailing tidal inlet dynamics (i.e. strong ebb flow at lagoon inlet), thus preventing the species to enter the lagoon. In order to restore the lagoon

  13. Assessment of possible diel and sex-related differences in round goby (Neogobius melanostomus) diet

    Czech Academy of Sciences Publication Activity Database

    Všetičková, Lucie; Janáč, Michal; Roche, Kevin Francis; Jurajda, Pavel

    2015-01-01

    Roč. 64, č. 2 (2015), s. 104-111 ISSN 0139-7893 R&D Projects: GA ČR(CZ) GAP505/11/1768 Institutional support: RVO:68081766 Keywords : invasive species * diel feeding * inter-sex differences * nest-guarding * breeding season Subject RIV: EG - Zoology Impact factor: 0.592, year: 2015

  14. Investigations into the diet and feeding ecology of the bearded goby ...

    African Journals Online (AJOL)

    Given the importance of this species in recycling benthic carbon through the foodweb of the northern Benguela ecosystem, there is a need to describe and quantify the benthic food environment. Keywords: Benguela, benthic-pelagic coupling, ecosystem approach to fisheries, infauna, polychaetes, zooplankton

  15. The diet of reservoir perch before, during and after establishment of non-native tubenose goby

    Czech Academy of Sciences Publication Activity Database

    Všetičková, Lucie; Mikl, Libor; Adámek, Zdeněk; Prášek, Václav; Roche, Kevin Francis; Jurajda, Pavel

    2018-01-01

    Roč. 419, č. 419 (2018), č. článku 4. ISSN 1961-9502 R&D Projects: GA ČR(CZ) GBP505/12/G112 Institutional support: RVO:68081766 Keywords : dietary shift * food preference * Gobiidae * invasive species * Perca fluviatilis * piscivore diet Subject RIV: EG - Zoology Impact factor: 1.217, year: 2016

  16. Evidence for ontogenetically and morphologically distinct alternative reproductive tactics in the invasive round Goby Neogobius melanostomus

    NARCIS (Netherlands)

    Bleeker, Katinka; Jong, De Karen; Kessel, Van Nils; Hinde, Camilla A.; Nagelkerke, Leopold A.J.

    2017-01-01

    Alternative reproductive tactics are characterized by the occurrence of discrete alternative morphs that differ in behavioural, morphological and physiological traits within the same sex. Although much effort has been made to describe the behaviour, morphology and physiology of such alternative

  17. Temporal effects on host-parasite associations in four naturalized goby species living in sympatry

    Czech Academy of Sciences Publication Activity Database

    Ondračková, Markéta; Valová, Zdenka; Hudcová, Iveta; Michálková, Veronika; Šimková, A.; Borcherding, J.; Jurajda, Pavel

    2015-01-01

    Roč. 746, č. 1 (2015), s. 233-243 ISSN 0018-8158 R&D Projects: GA ČR(CZ) GAP505/12/2569 Institutional support: RVO:68081766 Keywords : Fish * Gobiidae * Non-native species * Parasite * Rhine Subject RIV: EG - Zoology Impact factor: 2.051, year: 2015

  18. Carcass feeding as a cryptic foraging mode in round goby Neogobius melanostomus

    Czech Academy of Sciences Publication Activity Database

    Polačik, Matej; Jurajda, Pavel; Blažek, Radim; Janáč, Michal

    2015-01-01

    Roč. 87, č. 1 (2015), s. 194-199 ISSN 0022-1112 R&D Projects: GA ČR(CZ) GAP505/11/1768 Institutional support: RVO:68081766 Keywords : diet * food web * necrophagy * trophic ecology Subject RIV: EG - Zoology Impact factor: 1.246, year: 2015

  19. Invasive Ponto-Caspian gobies in the diet of piscivorous fish in a European lowland river

    Czech Academy of Sciences Publication Activity Database

    Mikl, Libor; Adámek, Zdeněk; Roche, Kevin Francis; Všetičková, Lucie; Šlapanský, Luděk; Jurajda, Pavel

    2017-01-01

    Roč. 190, č. 2 (2017), s. 157-171 ISSN 1863-9135 R&D Projects: GA ČR(CZ) GBP505/12/G112 Institutional support: RVO:68081766 Keywords : invasive gobiids * fish prey * predatory fish diet * food web structure * invasive species impacts Subject RIV: EG - Zoology OBOR OECD: Marine biology, freshwater biology, limnology Impact factor: 1.170, year: 2016

  20. Expansion of round gobies in a non-navigable river system

    Czech Academy of Sciences Publication Activity Database

    Šlapanský, Luděk; Janáč, Michal; Roche, Kevin Francis; Mikl, Libor; Jurajda, Pavel

    2017-01-01

    Roč. 67, November (2017), s. 27-36 ISSN 0075-9511 R&D Projects: GA ČR(CZ) GAP505/11/1768 Institutional support: RVO:68081766 Keywords : Impact * Invasive species * Neogobius melanostomus * Pioneer fish * Population characteristics * Proterorhinus semilunaris Subject RIV: EH - Ecology, Behaviour OBOR OECD: Marine biology, freshwater biology, limnology Impact factor: 1.427, year: 2016

  1. Globalising Assessment: An Ethnography of Literacy Assessment, Camels and Fast Food in the Mongolian Gobi

    Science.gov (United States)

    Maddox, Bryan

    2014-01-01

    What happens when standardised literacy assessments travel globally? The paper presents an ethnographic account of adult literacy assessment events in rural Mongolia. It examines the dynamics of literacy assessment in terms of the movement and re-contextualisation of test items as they travel globally and are received locally by Mongolian…

  2. The Tsenkher Structure in the Gobi-Altai, Mongolia: Preliminary Results from the 2007 Expedition

    Science.gov (United States)

    Komatsu, G.; Ormö, J.; Bayaraa, T.; Matsui, T.; Gereltsetseg, L.; Tserendug, S.; Goto, K.; Gomez-Ortiz, D.; Demberel, S.

    2008-03-01

    The 3.6-3.7 km Tsenkher structure located in Mongolia was proposed to be an impact crater. Volcanic hypotheses are not ruled out, but its uplifted rim, extensive breccia deposit, and rootless structure are consistent with an impact origin.

  3. Geophysical survey of the proposed Tsenkher impact structure, Gobi Altai, Mongolia

    Science.gov (United States)

    Ormö, Jens; Gomez-Ortiz, David; Komatsu, Goro; Bayaraa, Togookhuu; Tserendug, Shoovdor

    2010-03-01

    We have performed forward magnetic and gravity modeling of data obtained during the 2007 expedition to the 3.7km in diameter, circular, Tsenkher structure, Mongolia, in order to evaluate the cause of its formation. Extensive occurrences of brecciated rocks, mainly in the form of an ejecta blanket outside the elevated rim of the structure, support an explosive origin (e.g., cosmic impact, explosive volcanism). The host rocks in the area are mainly weakly magnetic, silica-rich sandstones, and siltstones. A near absence of surface exposures of volcanic rocks makes any major volcanic structures (e.g., caldera) unlikely. Likewise, the magnetic models exclude any large, subsurface, intrusive body. This is supported by an 8mGal gravity low over the structure indicating a subsurface low density body. Instead, the best fit is achieved for a bowl-shaped structure with a slight central rise as expected for an impact crater of this size in mainly sedimentary target. The structure can be either root-less (i.e., impact crater) or rooted with a narrow feeder dyke with relatively higher magnetic susceptibility and density (i.e., volcanic maar crater). The geophysical signature, the solitary appearance, the predominantly sedimentary setting, and the comparably large size of the Tsenkher structure favor the impact crater alternative. However, until mineralogical/geochemical evidence for an impact is presented, the maar alternative remains plausible although exceptional as it would make the Tsenkher structure one of the largest in the world in an unusual setting for maar craters.

  4. A newly established round goby (Neogobius melanostomus) population in the upper stretch of the river Elbe

    Czech Academy of Sciences Publication Activity Database

    Roche, Kevin Francis; Janáč, Michal; Šlapanský, Luděk; Mikl, Libor; Kopeček, Lukáš; Jurajda, Pavel

    2015-01-01

    Roč. 416, č. 33 (2015), s. 33 ISSN 1961-9502 R&D Projects: GA ČR(CZ) GAP505/11/1768 Institutional support: RVO:68081766 Keywords : Gobiidae * species introduction * non-native species * population expansion * ship-mediated transport Subject RIV: EH - Ecology, Behaviour Impact factor: 0.978, year: 2015

  5. An Anthropologist among the Psychometricians: Assessment Events, Ethnography, and Differential Item Functioning in the Mongolian Gobi

    Science.gov (United States)

    Maddox, Bryan; Zumbo, Bruno D.; Tay-Lim, Brenda; Qu, Demin

    2015-01-01

    This article explores the potential for ethnographic observations to inform the analysis of test item performance. In 2010, a standardized, large-scale adult literacy assessment took place in Mongolia as part of the United Nations Educational, Scientific and Cultural Organization Literacy Assessment and Monitoring Programme (LAMP). In a novel form…

  6. The use of environmental DNA in invasive species surveillance of the Great Lakes commercial bait trade.

    Science.gov (United States)

    Nathan, Lucas R; Jerde, Christopher L; Budny, Michelle L; Mahon, Andrew R

    2015-04-01

    Over 180 non-native species have been introduced in the Laurentian Great Lakes region, many posing threats to native species and ecosystem functioning. One potential pathway for introductions is the commercial bait trade; unknowing or unconcerned anglers commonly release unused bait into aquatic systems. Previous surveillance efforts of this pathway relied on visual inspection of bait stocks in retail shops, which can be time and cost prohibitive and requires a trained individual that can rapidly and accurately identify cryptic species. Environmental DNA (eDNA) surveillance, a molecular tool that has been used for surveillance in aquatic environments, can be used to efficiently detect species at low abundances. We collected and analyzed 576 eDNA samples from 525 retail bait shops throughout the Laurentian Great Lake states. We used eDNA techniques to screen samples for multiple aquatic invasive species (AIS) that could be transported in the bait trade, including bighead (Hypophthalmichthys nobilis) and silver carp (H. molitrix), round goby (Neogobius melanostomus), tubenose goby (Proterorhinus marmoratus), Eurasian rudd (Scardinius erythrophthalmus), and goldfish (Carassius auratus). Twenty-seven samples were positive for at least one target species (4.7% of samples), and all target species were found at least once, except bighead carp. Despite current regulations, the bait trade remains a potential pathway for invasive species introductions in the Great Lakes region. Alterations to existing management strategies regarding the collection, transportation, and use of live bait are warranted, including new and updated regulations, to prevent future introductions of invasive species in the Great Lakes via the bait trade. © 2014 Society for Conservation Biology.

  7. Composition of Fish Communities in a European Macrotidal Salt Marsh (the Mont Saint-Michel Bay, France)

    Science.gov (United States)

    Laffaille, P.; Feunteun, E.; Lefeuvre, J.-C.

    2000-10-01

    At least 100 fish species are known to be present in the intertidal areas (estuaries, mudflats and salt marshes) of Mont Saint-Michel Bay. These and other comparable shallow marine coastal waters, such as estuaries and lagoons, play a nursery role for many fish species. However, in Europe little attention has been paid to the value of tidal salt marshes for fishes. Between March 1996 and April 1999, 120 tides were sampled in a tidal creek. A total of 31 species were caught. This community was largely dominated by mullets ( Liza ramada represent 87% of the total biomass) and sand gobies ( Pomatoschistus minutus and P. lozanoi represent 82% of the total numbers). These species and also Gasterosteus aculeatus , Syngnathus rostellatus, Dicentrarchus labrax, Mugil spp., Liza aurata and Sprattus sprattus were the most frequent species (>50% of monthly frequency of occurrence). In Europe, salt marshes and their creeks are flooded only during high spring tides. So, fishes only invade this environment during short immersion periods, and no species can be considered as marsh resident. But, the salt marsh was colonized by fish every time the tide reached the creek, and during the short time of flood, dominant fishes fed actively and exploited the high productivity. Nevertheless, this study shows that there is little interannual variation in the fish community and there are three ' seasons ' in the fish fauna of the marsh. Marine straggler and marine estuarine dependent species colonize marshes between spring (recruitment period in the bay) and autumn before returning into deeper adjacent waters. Estuarine fishes are present all year round with maximum abundances in the end of summer. The presence of fishes confirms that this kind of wetland plays an important trophic and nursery role for these species. Differences in densities and stages distribution of these species into Mont Saint-Michel systems (tidal mudflats, estuaries and tidal salt marshes) can reduce the trophic

  8. Influence of the invasive Asian clam Corbicula fluminea (Bivalvia: Corbiculidae) on estuarine epibenthic assemblages

    Science.gov (United States)

    Ilarri, M. I.; Souza, A. T.; Antunes, C.; Guilhermino, L.; Sousa, R.

    2014-04-01

    One of the most widespread invasive alien species (IAS) in aquatic ecosystems is the Asian clam Corbicula fluminea. Several studies have shown that C. fluminea can cause large-scale changes in macrozoobenthic assemblages; however, very few attempted to investigate the effects of this IAS on mobile epibenthic species, such as fishes and crustaceans. In this context, the influence of C. fluminea on epibenthic species was investigated during one year by comparing the associated epibenthic fauna in three nearby sites of the Minho estuary (NW of the Iberian Peninsula), wherein the abiotic conditions are similar but the density of the Asian clam is highly different. From a total of 13 species, six were significantly influenced by C. fluminea; five responded positively, namely the brown shrimp Crangon crangon, the European eel Anguilla anguilla, the common goby Pomatoschistus microps, the brown trout Salmo trutta fario and the great pipefish Syngnathus acus, whereas the shore crab Carcinus maenas was negatively influenced. However, stomach contents analysis revealed that fish and crustacean species do not feed on C. fluminea, suggesting that this IAS is still not a large component of the diet of higher trophic levels in this estuarine ecosystem. Our results suggest that the structure provided by C. fluminea shells is likely to be one of the main factors responsible for the differences observed. C. fluminea physical structure seems to influence the epibenthic associated fauna, when found in densities higher than 1000 ind./m2, with sedentary small-bodied crustaceans and fishes being mainly attracted by the increasing in habitat complexity and consequent enhancement of heterogeneity and shelter availability.

  9. Age at maturity of Mediterranean marine fishes

    Directory of Open Access Journals (Sweden)

    A. C. TSIKLIRAS

    2014-07-01

    Full Text Available In this review we collected data on the age at maturity (tm and maximum reported age (tmax for 235 stocks of Mediterranean marine fishes, belonging to 82 species, 37 families, 12 orders and 2 classes (Actinopterygii and Elasmobranchii. Among Actinopterygii (mean tm ± SD = 2.20 ± 1.43 y, n = 215, tm ranged from 0.3 y, for the common goby Pomatoschistus microps, to 12 y, for dusky grouper Epinephelus marginatus, while among Elasmobranchii (mean tm ± SD = 5.94 ± 2.47 y, n = 20, tm ranged between 2.7 y, for brown ray Raja miraletus, and 12 y for picked dogfish Squalus acanthias. Overall, the tmax ranged between 1 y, for transparent goby Aphia minuta, and 70 y, for wreckfish Polyprion americanus. The mean tmax of Actinopterygii (tmax ± SD = 10.14 ± 9.42 y was lower than that of Elasmobranchii (tmax ± SD = 14.05 ± 8.47 y. The tm exhibited a strong positive linear relation with tmax for both Actinopterygii (logtm = 0.58 ´ logtmax – 0.25, r2 = 0.51, P < 0.001 and Elasmobranchii (logtm = 0.67 ´ logtmax – 0.006, r2 = 0.51, P = 0.007. The mean tm/tmax did not differ significantly with sex within Actinopterygii (ANOVA: F = 0.27, P = 0.60, n = 90; females: mean ± SD = 0.276 ± 0.143; males: mean ± SD = 0.265 ± 0.138 and Elasmobranchii (ANOVA: F = 1.44, P = 0.25, n = 10; females: mean ± SD = 0.499 ± 0.166; males: mean ± SD = 0.418 ± 0.133. Finally, the dimensionless ratio tm/tmax was significantly lower (ANOVA: F = 31.04, P < 0.001 for Actinopterygii (mean ± SD = 0.270 ± 0.135, n = 180 than for Elasmobranchii, (mean ± SD = 0.458 ± 0.152, n = 20, when stocks with combined sexes were excluded from the analysis.

  10. A new genus of proteocephalid tapeworm (Cestoda) from the marbled swamp eel Synbranchus marmoratus Bloch (Synbranchiformes: Synbranchidae) in the River Parana basin, Argentina

    Czech Academy of Sciences Publication Activity Database

    Arredondo, N.J.; Alves, Philippe Vieira; Gil de Pertierra, A.A.

    2017-01-01

    Roč. 64, MAY 5 (2017), č. článku 015. ISSN 1803-6465 R&D Projects: GA ČR(CZ) GBP505/12/G112 Institutional support: RVO:60077344 Keywords : Proteocephalidae * Monticelliinae * taxonomy * morphology * phylogenetic analysis * freshwater * Neotropical Region Subject RIV: GJ - Animal Vermins ; Diseases, Veterinary Medicine OBOR OECD: Veterinary science Impact factor: 1.082, year: 2016

  11. Molecular and cytogenetic analyses of cryptic species within the Synbranchus marmoratus Bloch, 1795 (Synbranchiformes: Synbranchidae grouping: species delimitations, karyotypic evolution and intraspecific diversification

    Directory of Open Access Journals (Sweden)

    Ricardo Utsunomia

    Full Text Available The fish species Synbranchus marmoratushas been reported to exist as a species complex due to high intraspecific karyotypic variability in spite of the difficulty or impossibility to distinguish them using morphological traits alone. The goal of this work was to use cytogenetic and molecular methods to determine the species delimitations and understand the karyoevolution ofS. marmoratususing samples collected from distinct Brazilian localities. Among the analyzed specimens, a large degree of cytogenetic variation related to diploid numbers and karyotype structure was observed, with karyotypes showing 2n=42, 44 and 46 chromosomes. In addition, using sequences of three mitochondrial genes, the phylogenetic relationships between every sample with a known karyotype were determined, which revealed significant nucleotide divergence among the karyomorphs. Also, the analyses indicate that chromosomal rearrangements occurred independently within the distinct lineages of S. marmoratuscomplex, which resulted in the appearance of distinct karyotypic variants in a non-linear fashion related to diploid numbers and in the appearance of similar non-homologous chromosomes. Finally, the integration of both molecular cytogenetic and phylogenetic approaches allowed the determination of specific chromosomes possibly involved in rearrangements and a better understanding about the evolutionary processes involved in the differentiation ofSynbranchusgenus.

  12. Range expansion and habitat preferences of nonnative 0+ tubenose goby (Proterorhinus semilunaris) in two lowland rivers in the Danube basin

    Czech Academy of Sciences Publication Activity Database

    Janáč, Michal; Valová, Zdenka; Jurajda, Pavel

    2012-01-01

    Roč. 181, č. 1 (2012), s. 73-85 ISSN 1863-9135 R&D Projects: GA ČR(CZ) GAP505/11/1768 Institutional support: RVO:68081766 Keywords : fish * Gobiidae * invasive species * microhabitat * colonization * dispersal Subject RIV: EH - Ecology, Behaviour Impact factor: 1.190, year: 2012

  13. Mongolian “Neolithic” and Early Bronze Age ground stone tools from the northern edge of the Gobi Desert

    Directory of Open Access Journals (Sweden)

    Joan S. Schneider

    2016-10-01

    Full Text Available The transition from the Mongolian Neolithic to the Bronze Age is not well understood. Within Ikh Nart Nature Reserve, over a period of five years, we identified a number of sites with dense surface artefact scatters and features that seem to represent this transition period. Evident in those concentrations are characteristic microblade cores, microblades, “thumbnail" flake scrapers, projectile points, ground stone tools, and stone features of unknown function. Between 2012 and 2014 we collected ground stone artefacts from four sites and sediment samples from three sites. With permission of Mongolian authorities, the artefacts from one site and sediment samples from three sites were sent for botanical analyses to the University of Texas, Austin, Environmental Archaeology Laboratory. Preliminary results indicate that plant remains are present on the ground stone artefacts: dendritic long-cells from a deep pore of one artefact and starch grains from the pores of six of the seven artefacts. These data present the first opportunity to understand what resources “Neolithic” people were processing with ground stone tools in this area and further our opportunity to better understand the little-known “Neolithic”-Early Bronze Age transition period in Central Asia. This paper describes the ground stone artefacts and further explores the results of data retrieved from some of these artefacts.

  14. Non-native western tubenose gobies Proterorhinus semilunaris show distinct site, sex and age-related differences in diet

    Czech Academy of Sciences Publication Activity Database

    Všetičková, Lucie; Janáč, Michal; Vašek, Mojmír; Roche, Kevin Francis; Jurajda, Pavel

    2014-01-01

    Roč. 414, č. 10 (2014), s. 1-19 ISSN 1961-9502 R&D Projects: GA ČR(CZ) GAP505/11/1768 Institutional support: RVO:68081766 Keywords : invasive species * Gobiidae * Proterorhinus semilunaris * diet * site-effect * sex-differences Subject RIV: EG - Zoology Impact factor: 0.928, year: 2014

  15. Invasion rate and population characteristics of the invasive round goby Neogobius melanostomus: effects of density and invasion history

    DEFF Research Database (Denmark)

    Azour, Farivar; Deurs, Mikael van; Behrens, Jane

    2015-01-01

    ). The established population revealed a broad age distribution and a 1:1 gender ratio, while fish from a recently invaded site were primarily of intermediate ages with a male-biased gender ratio. Otolith analyses suggested that the oldest individuals from the recently invaded area experienced superior growth...

  16. No effect of round goby Neogobius melanostomus colonisation on young-of-the-year fish density or microhabitat use

    Czech Academy of Sciences Publication Activity Database

    Janáč, Michal; Valová, Zdenka; Roche, Kevin Francis; Jurajda, Pavel

    2016-01-01

    Roč. 18, č. 8 (2016), s. 2333-2347 ISSN 1387-3547 R&D Projects: GA ČR(CZ) GAP505/11/1768 Institutional support: RVO:68081766 Keywords : Invasive species * Niche shift * Neogobius melanostomus * Proterorhinus semilunaris * Impact Subject RIV: EH - Ecology, Behaviour Impact factor: 2.473, year: 2016

  17. The parasite community of round goby Neogobius melanostomus (Pallas, 1814) (Actinopterygii: Gobiidae) newly introduced into the upper Elbe

    Czech Academy of Sciences Publication Activity Database

    Kvach, Yuriy; Ondračková, Markéta; Janáč, Michal; Jurajda, Pavel

    2017-01-01

    Roč. 418, April (2017), č. článku 19. ISSN 1961-9502 R&D Projects: GA ČR(CZ) GBP505/12/G112 Institutional support: RVO:68081766 Keywords : enemy release hypothesis * Neogobius melanostomus * North Sea basin * parasite spillback * Pomphorhynchus tereticollis Subject RIV: EG - Zoology OBOR OECD: Marine biology, freshwater biology, limnology Impact factor: 1.217, year: 2016

  18. Cryptic species of Ponto-Caspian bighead goby of the genus Ponticola (Gobiidae)

    DEFF Research Database (Denmark)

    Vasil'eva, E. D.; Schwarzhans, Werner; Medvedev, D. A.

    2016-01-01

    . gorlap which inhabits the northern, western, and southern Caspian Sea. These three allopatric species have ctenoid scales to varying degrees on the crown and nape (100% presence in P. kessleri and complete absence in P. iljini), and there are small differences in the shape of the head, the thickness...... of the beginning of divergence of the considered three cryptic species, as well as isolating barriers that led to allopatric speciation, are discussed....

  19. Pelagic occurrence and diet of invasive round goby Neogobius melanostomus (Actinopterygii, Gobiidae) juveniles in deep well-mixed European reservoirs.

    Czech Academy of Sciences Publication Activity Database

    Jůza, Tomáš; Zemanová, Jana; Tušer, Michal; Sajdlová, Zuzana; Baran, Roman; Vašek, Mojmír; Ricard, Daniel; Blabolil, Petr; Wagenvoort, A. J.; Ketelaars, H. A. M.; Kubečka, Jan

    2016-01-01

    Roč. 768, č. 1 (2016), s. 197-209 ISSN 0018-8158 R&D Projects: GA MŠk(CZ) EE2.3.20.0204; GA MŠk(CZ) EE2.3.30.0032 Institutional support: RVO:60077344 Keywords : Biesbosch reservoirs * fish community composition changes * invasive species * vertical distribution * length distribution * fry trawling Subject RIV: EH - Ecology, Behaviour Impact factor: 2.056, year: 2016

  20. Feeding kinematics and performance of Hawaiian stream gobies, Awaous guamensis and Lentipes concolor: linkage of functional morphology and ecology.

    Science.gov (United States)

    Maie, Takashi; Wilson, Megan P; Schoenfuss, Heiko L; Blob, Richard W

    2009-03-01

    Distributions of Hawaiian stream fishes are typically interrupted by waterfalls that divide streams into multiple segments. Larvae hatch upstream, are flushed into the ocean, and must climb these waterfalls to reach adult habitats when returning back to freshwater as part of an amphidromous life cycle. Stream surveys and studies of climbing performance show that Lentipes concolor Gill can reach fast-flowing upper stream segments but that Awaous guamensis Valenciennes reaches only slower, lower stream segments. Gut content analyses for these two species indicate considerable overlap in diet, suggesting that feeding kinematics and performance of these two species might be comparable. Alternatively, feeding kinematics and performance of these species might be expected to differ in relation to the different flow regimes in their habitat (feeding in faster stream currents for L. concolor versus in slower currents for A. guamensis). To test these alternative hypotheses, we compared food capturing kinematics and performance during suction feeding behaviors of A. guamensis and L. concolor using morphological data and high-speed video. Lentipes concolor showed both a significantly larger gape angle and faster jaw opening than A. guamensis. Geometric models calculated that despite the inverse relationship of gape size and suction pressure generation, the fast jaw motions of L. concolor allow it to achieve higher pressure differentials than A. guamensis. Such elevated suction pressure would enhance the ability of L. concolor to successfully capture food in the fast stream reaches it typically inhabits. Differences in jaw morphology may contribute to these differences in performance, as the lever ratio for jaw opening is about 10% lower in L. concolor compared with A. guamensis, suiting the jaws of L. concolor better for fast opening. Copyright 2008 Wiley-Liss, Inc.

  1. Evolutionary Novelty versus Exaptation: Oral Kinematics in Feeding versus Climbing in the Waterfall-Climbing Hawaiian Goby Sicyopterus stimpsoni

    OpenAIRE

    Cullen, Joshua A.; Maie, Takashi; Schoenfuss, Heiko L.; Blob, Richard W.

    2013-01-01

    Species exposed to extreme environments often exhibit distinctive traits that help meet the demands of such habitats. Such traits could evolve independently, but under intense selective pressures of extreme environments some existing structures or behaviors might be coopted to meet specialized demands, evolving via the process of exaptation. We evaluated the potential for exaptation to have operated in the evolution of novel behaviors of the waterfall-climbing gobiid fish genus Sicyopterus. T...

  2. Evolutionary novelty versus exaptation: oral kinematics in feeding versus climbing in the waterfall-climbing Hawaiian Goby Sicyopterus stimpsoni.

    Directory of Open Access Journals (Sweden)

    Joshua A Cullen

    Full Text Available Species exposed to extreme environments often exhibit distinctive traits that help meet the demands of such habitats. Such traits could evolve independently, but under intense selective pressures of extreme environments some existing structures or behaviors might be coopted to meet specialized demands, evolving via the process of exaptation. We evaluated the potential for exaptation to have operated in the evolution of novel behaviors of the waterfall-climbing gobiid fish genus Sicyopterus. These fish use an "inching" behavior to climb waterfalls, in which an oral sucker is cyclically protruded and attached to the climbing surface. They also exhibit a distinctive feeding behavior, in which the premaxilla is cyclically protruded to scrape diatoms from the substrate. Given the similarity of these patterns, we hypothesized that one might have been coopted from the other. To evaluate this, we filmed climbing and feeding in Sicyopterus stimpsoni from Hawai'i, and measured oral kinematics for two comparisons. First, we compared feeding kinematics of S. stimpsoni with those for two suction feeding gobiids (Awaous guamensis and Lentipes concolor, assessing what novel jaw movements were required for algal grazing. Second, we quantified the similarity of oral kinematics between feeding and climbing in S. stimpsoni, evaluating the potential for either to represent an exaptation from the other. Premaxillary movements showed the greatest differences between scraping and suction feeding taxa. Between feeding and climbing, overall profiles of oral kinematics matched closely for most variables in S. stimpsoni, with only a few showing significant differences in maximum values. Although current data cannot resolve whether oral movements for climbing were coopted from feeding, or feeding movements coopted from climbing, similarities between feeding and climbing kinematics in S. stimpsoni are consistent with evidence of exaptation, with modifications, between these behaviors. Such comparisons can provide insight into the evolutionary mechanisms facilitating exploitation of extreme habitats.

  3. Evolutionary novelty versus exaptation: oral kinematics in feeding versus climbing in the waterfall-climbing Hawaiian Goby Sicyopterus stimpsoni.

    Science.gov (United States)

    Cullen, Joshua A; Maie, Takashi; Schoenfuss, Heiko L; Blob, Richard W

    2013-01-01

    Species exposed to extreme environments often exhibit distinctive traits that help meet the demands of such habitats. Such traits could evolve independently, but under intense selective pressures of extreme environments some existing structures or behaviors might be coopted to meet specialized demands, evolving via the process of exaptation. We evaluated the potential for exaptation to have operated in the evolution of novel behaviors of the waterfall-climbing gobiid fish genus Sicyopterus. These fish use an "inching" behavior to climb waterfalls, in which an oral sucker is cyclically protruded and attached to the climbing surface. They also exhibit a distinctive feeding behavior, in which the premaxilla is cyclically protruded to scrape diatoms from the substrate. Given the similarity of these patterns, we hypothesized that one might have been coopted from the other. To evaluate this, we filmed climbing and feeding in Sicyopterus stimpsoni from Hawai'i, and measured oral kinematics for two comparisons. First, we compared feeding kinematics of S. stimpsoni with those for two suction feeding gobiids (Awaous guamensis and Lentipes concolor), assessing what novel jaw movements were required for algal grazing. Second, we quantified the similarity of oral kinematics between feeding and climbing in S. stimpsoni, evaluating the potential for either to represent an exaptation from the other. Premaxillary movements showed the greatest differences between scraping and suction feeding taxa. Between feeding and climbing, overall profiles of oral kinematics matched closely for most variables in S. stimpsoni, with only a few showing significant differences in maximum values. Although current data cannot resolve whether oral movements for climbing were coopted from feeding, or feeding movements coopted from climbing, similarities between feeding and climbing kinematics in S. stimpsoni are consistent with evidence of exaptation, with modifications, between these behaviors. Such comparisons can provide insight into the evolutionary mechanisms facilitating exploitation of extreme habitats.

  4. Papel ecológico en la cadena trófica de los peces que pasan el invierno en ecosistema de la laguna Culbin Sands, NE Escocia: Identificación de las principales interacciones tróficas y comprovación de los efectos del pez Pomatoschistus microps (Pall

    OpenAIRE

    Mariyam Mendonça, Vanda; Raffaelli, David; Boyle, Peter; Emes, Chas

    2007-01-01

    Se estudió el ecosistema de la laguna Culbin Sands, NE Escocia, durante un periodo de tres años (1994-1996) con objeto de identificar los principales acoplamientos tróficos desde invertebrados bentónicos a depredadores epibentónicos, y para evaluar el impacto de los peces que pasan el invierno sobre las comunidades de sus presas. Cada 2-4 semanas, la fauna móvil se muestreó para estudiar su dieta. Las principales interacciones tróficas identificadas, entre invertebrados bentóncos y depredador...

  5. Dicty_cDB: VHA227 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available um chromoso... 33 7.5 AY698035_1( AY698035 |pid:none) Desmognathus marmoratus isolate 69... 33 7.5 AY612348_...1( AY612348 |pid:none) Desmognathus quadramaculatus vouch... 33 9.9 AY698038_1( AY698038 |pid:none) Desmogna...thus marmoratus isolate T0... 33 9.9 AY612344_1( AY612344 |pid:none) Desmognathus... marmoratus voucher KH... 33 9.9 AY698041_1( AY698041 |pid:none) Desmognathus marmoratus isolate T0... 33 9.

  6. PPARα, PPARγ and SREBP-1 pathways mediated waterborne iron (Fe)-induced reduction in hepatic lipid deposition of javelin goby Synechogobius hasta.

    Science.gov (United States)

    Chen, Guang-Hui; Luo, Zhi; Chen, Feng; Shi, Xi; Song, Yu-Feng; You, Wen-Jing; Liu, Xu

    2017-07-01

    The 42-day experiment was conducted to investigate the effects and mechanism of waterborne Fe exposure influencing hepatic lipid deposition in Synechogobius hasta. For that purpose, S. hasta were exposed to four Fe concentrations (0 (control), 0.36, 0.72 and 1.07μM Fe) for 42days. On days 21 and 42, morphological parameters, hepatic lipid deposition and Fe contents, and activities and mRNA levels of enzymes and genes related to lipid metabolism, including lipogenic enzymes (6PGD, G6PD, ME, ICDH, FAS and ACC) and lipolytic enzymes (CPTI, HSL), were analyzed. With the increase of Fe concentration, hepatic Fe content tended to increase but HSI and lipid content tended to decrease. On day 21, Fe exposure down-regulated the lipogenic activities of 6PGD, G6PD, ICDH and FAS as well as the mRNA levels of G6PD, ACCa, FAS, SREBP-1 and PPARγ, but up-regulated CPT I, HSLa and PPARα mRNA levels. On day 42, Fe exposure down-regulated the lipogenic activities of 6PGD, G6PD, ICDH and FAS as well as the mRNA levels of 6PGD, ACCa, FAS and SREBP-1, but up-regulated CPT I, HSLa, PPARα and PPARγ mRNA levels. Using primary S. hasta hepatocytes, specific pathway inhibitors (GW6471 for PPARα and fatostatin for SREBP-1) and activator (troglitazone for PPARγ) were used to explore the signaling pathways of Fe reducing lipid deposition. The GW6471 attenuated the Fe-induced down-regulation of mRNA levels of 6PGD, G6PD, ME, FAS and ACCa, and attenuated the Fe-induced up-regulation of mRNA levels of CPT I, HSLa and PPARα. Compared with single Fe-incubated group, the mRNA levels of G6PD, ME, FAS, ACCa, ACCb and PPARγ were up-regulated while the CPT I mRNA levels were down-regulated after troglitazone pre-treatment; fatostatin pre-treatment down-regulated the mRNA levels of 6PGD, ME, FAS, ACCa, ACCb and SREBP-1, and increased the CPT I and HSLa mRNA levels. Based on these results above, our study indicated that Fe exposure reduced hepatic lipid deposition by down-regulating lipogenesis and up-regulating lipolysis, and PPARα, PPARγ and SREBP-1 pathways mediated the Fe-induced reduction of hepatic lipid deposition in S. hasta. Copyright © 2017 Elsevier Inc. All rights reserved.

  7. Dentirumai philippinensis n. gen., n. sp (Nematoda: Philometridae), a new tissue-infecting philometrid nematode from the loach goby Rhyacichthys aspro (Valenciennes) (Rhyacichthyidae) in the Philippines

    Czech Academy of Sciences Publication Activity Database

    Quiazon, K.M.A.; Moravec, František

    2013-01-01

    Roč. 87, č. 1 (2013), s. 59-65 ISSN 0022-149X R&D Projects: GA MŠk LC522 Institutional support: RVO:60077344 Keywords : Philometridae * Phillipine Archipelago * Parasitic nematode Subject RIV: EA - Cell Biology Impact factor: 1.303, year: 2013

  8. Karyotype divergence and spreading of 5S rDNA sequences between genomes of two species: darter and emerald gobies ( Ctenogobius , Gobiidae).

    Science.gov (United States)

    Lima-Filho, P A; Bertollo, L A C; Cioffi, M B; Costa, G W W F; Molina, W F

    2014-01-01

    Karyotype analyses of the cryptobenthic marine species Ctenogobius boleosoma and C. smaragdus were performed by means of classical and molecular cytogenetics, including physical mapping of the multigene 18S and 5S rDNA families. C. boleosoma has 2n = 44 chromosomes (2 submetacentrics + 42 acrocentrics; FN = 46) with a single chromosome pair each carrying 18S and 5S ribosomal sites; whereas C. smaragdus has 2n = 48 chromosomes (2 submetacentrics + 46 acrocentrics; FN = 50), also with a single pair bearing 18S rDNA, but an extensive increase in the number of GC-rich 5S rDNA sites in 21 chromosome pairs. The highly divergent karyotypes among Ctenogobius species contrast with observations in several other marine fish groups, demonstrating an accelerated rate of chromosomal evolution mediated by both chromosomal rearrangements and the extensive dispersion of 5S rDNA sequences in the genome. © 2014 S. Karger AG, Basel.

  9. Early engagement of stakeholders with individual-based modelling can inform research for improving invasive species management: the round goby as a case study

    DEFF Research Database (Denmark)

    Samson, Emma; Hirsch, Philipp E.; Palmer, Stephen C.

    2017-01-01

    Individual-based models (IBMs) incorporating realistic representations of key range-front processes such as dispersal can be used as tools to investigate the dynamics of invasive species. Managers can apply insights from these models to take effective action to prevent further spread and prioriti...

  10. Seasonal diet pattern of non-native tubenose goby (Proterorhinus semilunaris) in the lowland reservoir (Mušov, Czech Republic)

    Czech Academy of Sciences Publication Activity Database

    Adámek, Z.; Jurajda, Pavel; Prášek, Václav; Sukop, I.

    2010-01-01

    Roč. 397, 02 (2010), s. 1-12 ISSN 1961-9502 R&D Projects: GA MŠk LC522 Institutional research plan: CEZ:AV0Z60930519 Keywords : Gobiidae * food * lowland reservoir * rip-rap bank * the Dyje River Subject RIV: EG - Zoology Impact factor: 0.304, year: 2010

  11. The Lost South Gobi Microcontinent: Protolith Studies of Metamorphic Tectonites and Implications for the Evolution of Continental Crust in Southeastern Mongolia

    Directory of Open Access Journals (Sweden)

    Matthew J. Heumann

    2013-08-01

    Full Text Available The Central Asian Orogenic Belt, or Altaids, is an amalgamation of volcanic arcs and microcontinent blocks that records a complex late Precambrian–Mesozoic accretionary history. Although microcontinents cored by Precambrian basement are proposed to play an integral role in the accretion process, a lack of isotopic data hampers volume estimates of newly produced arc-derived versus old-cratonic crust in southeastern Mongolia. This study investigates metamorphic tectonites in southern Mongolia that have been mapped as Precambrian in age, largely on the basis of their high metamorphic grade and high strain. Here we present results from microstructural analyses and U-Pb zircon geochronology on samples from Tavan Har (44.05° N, 109.55° E and the Yagan-Onch Hayrhan metamorphic core complex (41.89° N, 104.24° E. Our results show no compelling evidence for Precambrian basement in southeastern Mongolia. Rather, the protoliths to all tectonites examined are Paleozoic–Mesozoic age rocks, formed during Devonian–Carboniferous arc magmatism and subsequent Permian–Triassic orogenesis during collision of the South Mongolia arc with the northern margin of China. These results yield important insights into the Paleozoic accretionary history of southern Mongolia, including the genesis of metamorphic and igneous basement during the Paleozoic, as well as implications for subsequent intracontinental reactivation.

  12. Stairway to heaven: evaluating levels of biological organization correlated with the successful ascent of natural waterfalls in the Hawaiian stream goby Sicyopterus stimpsoni.

    Directory of Open Access Journals (Sweden)

    Heiko L Schoenfuss

    Full Text Available Selective pressures generated by locomotor challenges act at the level of the individual. However, phenotypic variation among individuals that might convey a selective advantage may occur across any of multiple levels of biological organization. In this study, we test for differences in external morphology, muscle mechanical advantage, muscle fiber type and protein expression among individuals of the waterfall climbing Hawaiian fish Sicyopterus stimpsoni collected from sequential pools increasing in elevation within a single freshwater stream. Despite predictions from previous laboratory studies of morphological selection, few directional morphometric changes in body shape were observed at successively higher elevations. Similarly, lever arm ratios associated with the main pelvic sucker, central to climbing ability in this species, did not differ between elevations. However, among climbing muscles, the adductor pelvicus complex (largely responsible for generating pelvic suction during climbing contained a significantly greater red muscle fiber content at upstream sites. A proteomic analysis of the adductor pelvicus revealed two-fold increases in expression levels for two respiratory chain proteins (NADH:ubiquinone reductase and cytochrome b that are essential for aerobic respiration among individuals from successively higher elevations. Assessed collectively, these evaluations reveal phenotypic differences at some, but not all levels of biological organization that are likely the result of selective pressures experienced during climbing.

  13. Stairway to heaven: evaluating levels of biological organization correlated with the successful ascent of natural waterfalls in the Hawaiian stream goby Sicyopterus stimpsoni.

    Science.gov (United States)

    Schoenfuss, Heiko L; Maie, Takashi; Moody, Kristine N; Lesteberg, Kelsey E; Blob, Richard W; Schoenfuss, Tonya C

    2013-01-01

    Selective pressures generated by locomotor challenges act at the level of the individual. However, phenotypic variation among individuals that might convey a selective advantage may occur across any of multiple levels of biological organization. In this study, we test for differences in external morphology, muscle mechanical advantage, muscle fiber type and protein expression among individuals of the waterfall climbing Hawaiian fish Sicyopterus stimpsoni collected from sequential pools increasing in elevation within a single freshwater stream. Despite predictions from previous laboratory studies of morphological selection, few directional morphometric changes in body shape were observed at successively higher elevations. Similarly, lever arm ratios associated with the main pelvic sucker, central to climbing ability in this species, did not differ between elevations. However, among climbing muscles, the adductor pelvicus complex (largely responsible for generating pelvic suction during climbing) contained a significantly greater red muscle fiber content at upstream sites. A proteomic analysis of the adductor pelvicus revealed two-fold increases in expression levels for two respiratory chain proteins (NADH:ubiquinone reductase and cytochrome b) that are essential for aerobic respiration among individuals from successively higher elevations. Assessed collectively, these evaluations reveal phenotypic differences at some, but not all levels of biological organization that are likely the result of selective pressures experienced during climbing.

  14. Dicty_cDB: VHK596 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available 34 4.7 AY698035_1( AY698035 |pid:none) Desmognathus marmoratus isolate 69... 33 6.1 AC116957_68( AC116957 |p...id:none) Dictyostelium discoideum chromoso... 33 8.0 AY612344_1( AY612344 |pid:none) Desmognathus marmoratus

  15. Dicty_cDB: VHA340 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available _1( AY698035 |pid:none) Desmognathus marmoratus isolate 69... 33 5.9 AC116957_68( AC116957 |pid:none) Dictyo...stelium discoideum chromoso... 33 7.6 AY612344_1( AY612344 |pid:none) Desmognathus marmoratus voucher KH...

  16. Dicty_cDB: VHC580 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available stridium thermocellum ATCC 2... 34 4.8 AY698035_1( AY698035 |pid:none) Desmognathus marmoratus isolate 69...... 33 6.2 AY612344_1( AY612344 |pid:none) Desmognathus marmoratus voucher KH... 33 8.2 AC116957_68( AC116957 |

  17. Characteristics of the ichthyofauna of a temperate microtidal estuary with a reverse salinity gradient, including inter-decadal comparisons.

    Science.gov (United States)

    Veale, L; Tweedley, J R; Clarke, K R; Hallett, C S; Potter, I C

    2014-11-01

    apex region, in which salinities reached 54 and temperatures 36° C, recorded the highest maximum density and, in terms of abundance, was dominated (90%) by three atherinid species, emphasizing the ability of this family to tolerate extreme conditions. Comparisons between the data for 2008-2010 and 1994 demonstrate that the spotted hardyhead Craterocephalus mugiloides and the common hardyhead Atherinomorus vaigiensis had colonized and become abundant in the Leschenault Estuary in the intervening period. This represents a southwards extension of the distribution of these essentially tropical species during a period of increasing coastal water temperatures as a result of climate change. The abundance of weed-associated species, e.g. the western gobbleguts Ostorhinchus rueppellii and the soldier Gymnapistes marmoratus, increased, whereas that of the longfinned goby Favonigobius lateralis decreased, probably reflecting increases in eutrophication and siltation, respectively. © 2014 The Fisheries Society of the British Isles.

  18. Dicty_cDB: VHL427 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available d:none) Dictyostelium discoideum chromoso... 33 7.5 AY698035_1( AY698035 |pid:none) Desmognathus marmoratus ...isolate 69... 33 7.5 AY612348_1( AY612348 |pid:none) Desmognathus quadramaculatus vouch... 33 9.8 AY698038_1...( AY698038 |pid:none) Desmognathus marmoratus isolate T0... 33 9.8 AY612344_1( AY612344 |pid:none) Desmog...nathus marmoratus voucher KH... 33 9.8 AY698041_1( AY698041 |pid:none) Desmognathus

  19. Enige metingen over het standaard metabolisme en het actief metabolisme bij Gobiidae

    NARCIS (Netherlands)

    Penning de Vries, F.W.T.

    1969-01-01

    An attempt was made to determine the "scope for activity" -maximal active metabolism minus basal metabolism and its relation to temperature in the three species Pomatoschistus minutus,P.lozanoi and P. microps, in order to find a possible explanation for the difference in their

  20. Invloed van temperatuur en zoutgehalte op de ontwikkeling van eieren van enkele soorten zeegrondels

    NARCIS (Netherlands)

    van Buurt, G.

    1974-01-01

    Eggs of closely related estuarine and neritic Pomatoschistus species were incubated at 24 different temperature-salinity combinations (ranges 10 to 25°C, 5 to 55 per thousand S). Rate of development, survival and larval length at hatch were recorded in relation to incubation conditions.

  1. Dicty_cDB: VHI137 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available alignments: (bits) Value AY698035_1( AY698035 |pid:none) Desmognathus marmoratus isolate 69... 40 0.067 AY6...12344_1( AY612344 |pid:none) Desmognathus marmoratus voucher KH... 40 0.088 DQ018662_1( DQ018662 |pid:none) ...Plethodon dunni isolate 75356 NADH... 37 0.57 AY612348_1( AY612348 |pid:none) Desmog...nathus quadramaculatus vouch... 36 1.3 AY698038_1( AY698038 |pid:none) Desmognathus marmoratus isolate T0...... 36 1.3 AY698041_1( AY698041 |pid:none) Desmognathus marmoratus isolate T0... 36 1.3 CP000270_2676( CP000

  2. Dicty_cDB: VHP481 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available g significant alignments: (bits) Value AY698035_1( AY698035 |pid:none) Desmognath...us marmoratus isolate 69... 40 0.060 AY612344_1( AY612344 |pid:none) Desmognathus marmoratus voucher KH... 4...0 0.079 DQ018662_1( DQ018662 |pid:none) Plethodon dunni isolate 75356 NADH... 38 0.30 AY612348_1( AY612348 |pid:none) Desmog...nathus quadramaculatus vouch... 36 1.1 AY698038_1( AY698038 |pid:none) Desmog...nathus marmoratus isolate T0... 36 1.1 AY698041_1( AY698041 |pid:none) Desmognathus marmoratus i

  3. Dicty_cDB: VHN394 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available ents: (bits) Value AY698035_1( AY698035 |pid:none) Desmognathus marmoratus isolate 69... 40 0.067 AY612344_1...on dunni isolate 75356 NADH... 37 0.57 AY612348_1( AY612348 |pid:none) Desmognath...us quadramaculatus vouch... 36 1.3 AY698038_1( AY698038 |pid:none) Desmognathus marmoratus isolate T0... 36 ...1.3 AY698041_1( AY698041 |pid:none) Desmognathus marmoratus isolate T0... 36 1.3 CP000270_2676( CP000270 |pi...( AY612344 |pid:none) Desmognathus marmoratus voucher KH... 40 0.087 DQ018662_1( DQ018662 |pid:none) Plethod

  4. Geochemical and isotopic characteristics and magma sources of the early Cretaceous trachybasalts of the Goby-Altai rift zone: an example of grabens in the Arts-Bogdo range

    International Nuclear Information System (INIS)

    Samojlov, V.S.; Yarmolyuk, V.V.; Kovalenko, V.I.; Ivanov, V.G.; Pakhol'chenko, Yu.A.

    1998-01-01

    Geochemical and isotopic-geochemical characteristics of the basalts of Early Cretaceous (Hoby-Altai rift zone; Arts-Bogdo region, Mongolia). Atomic absorption spectroscopy, X-ray fluorescence spectroscopy, photometry, mass spectroscopy and other methods were used. Mantle nature of the basalt geochemical specificity is shown as well as their initial melts. Data on the rubidium-strontium isotopic composition of Neocomian basalts are the following ones: 87 Sr/ 86 Sr 87 Sr/ 86 Sr > 0.707 and Rb/Sr > 0.06 [ru

  5. Diet composition and food consumption rate of harbor porpoises (Phocoena phocoena ) in the western Baltic Sea

    DEFF Research Database (Denmark)

    Andreasen, Heidi; Ross, Stine Dalmann; Siebert, Ursula

    2017-01-01

    frequently consumed gobies. Here, the mass contribution by gobies was on aver-age 25%, which was as much as cod. Other species such as whiting, sprat, eelpout, and sandeels were of minor importance for both juveniles and adults. The diet compo- sition differed between years, quarters, and porpoise...

  6. Dicty_cDB: Contig-U12390-1 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available .......................done Score E Sequences producing significant alignments: (bits) Value AY698035_1( AY698035 |pid:none) Desmog...nathus marmoratus isolate 69... 40 0.18 AY612344_1( AY612344 |pid:none) Desmog...isolate 75356 NADH... 38 0.92 AY612348_1( AY612348 |pid:none) Desmognathus quadramaculatus vouch... 36 3.5 A...Y698038_1( AY698038 |pid:none) Desmognathus marmoratus isolate T0... 36 3.5 AY698...041_1( AY698041 |pid:none) Desmognathus marmoratus isolate T0... 36 3.5 CP000270_2676( CP000270 |pid:none) B

  7. Invasion strategy and abiotic activity triggers for non-native gobiids of the River Rhine.

    Directory of Open Access Journals (Sweden)

    Jan Baer

    Full Text Available The 24 hour activity patterns of three non-native gobiids (round goby Neogobius melanostomus, Western tubenose goby Proterorhinus semilunaris and bighead goby Ponticola kessleri were assessed over 46 consecutive months between 2011 and 2014 from their occurrence in the cooling water intake of a nuclear power plant on the River Rhine, Germany. In total, 117717 gobiids were identified and classified. The occurrence of all three species varied strongly between sampling years, and species-specific activity triggers were identified. The activity of juveniles of all three gobiids species was positively temperature dependent while adult tubenose goby activity appeared to be negatively temperature dependent. Increasing fluvial discharge in the adjoining main river stimulated the activity of juvenile round goby but inhibited activity of adult tubenose goby. Except for adult bighead goby, activity was also structured by time of day, but with no uniform mean. Meteorological factors such as precipitation, air pressure and duration of sunshine hours had little or no influence on gobiid activity. On selected rare occasions, mainly at night, all three species exhibited pulsed swarming behaviour, with thousands of individuals recorded in the intake water. Round goby swarms exhibited both the highest intensity and the largest swarming individuals, suggesting a potential competitive advantage over tubenose and bighead goby. Electric fishing surveys in natural river stretches corroborated this observation. Negative effects on the native fish fauna were apparent only for the bullhead, Cottus gobio. The activity triggers identified offer a unique insight into the invasion mechanisms of these ecosystem-changing non-native gobiids.

  8. Trophic structure and community stability in an overfished ecosystem

    KAUST Repository

    Utne-Palm, Anne Christine

    2010-07-15

    Since the collapse of the pelagic fisheries off southwest Africa in the late 1960s, jellyfish biomass has increased and the structure of the Benguelan fish community has shifted, making the bearded goby (Sufflogobius bibarbatus) the new predominant prey species. Despite increased prédation pressure and a harsh environment, the gobies are thriving. Here we show that physiological adaptations and antipredator and foraging behaviors underpin the success of these fish. In particular, body-tissue isotope signatures reveal that gobies consume jellyfish and sulphidic diatomaceous mud, transferring "dead-end" resources back into the food chain.

  9. Trophic structure and community stability in an overfished ecosystem

    KAUST Repository

    Utne-Palm, Anne Christine; Salvanes, Anne Gro Vea; Currie, Bronwen; Kaartvedt, Stein; Nilsson, Gö ran E.; Braithwaite, Victoria A.; Stecyk, Jonathan A W; Hundt, Matthias; Van Der Bank, Megan G.; Flynn, Bradley A.; Sandvik, Guro Katrine; Klevjer, Thor Aleksander; Sweetman, Andrew K.; Brü chert, Volker; Pittman, Karin A.; Peard, Kathleen R.; Lunde, Ida Gjervold; Strandaba, R. A U; Gibbons, Mark J.

    2010-01-01

    Since the collapse of the pelagic fisheries off southwest Africa in the late 1960s, jellyfish biomass has increased and the structure of the Benguelan fish community has shifted, making the bearded goby (Sufflogobius bibarbatus) the new predominant prey species. Despite increased prédation pressure and a harsh environment, the gobies are thriving. Here we show that physiological adaptations and antipredator and foraging behaviors underpin the success of these fish. In particular, body-tissue isotope signatures reveal that gobies consume jellyfish and sulphidic diatomaceous mud, transferring "dead-end" resources back into the food chain.

  10. Visible-light photocatalytic activity of graphene oxide-wrapped Bi2WO6 hierarchical microspheres

    Science.gov (United States)

    Zhai, Jiali; Yu, Hongwen; Li, Haiyan; Sun, Lei; Zhang, Kexin; Yang, Hongjun

    2015-07-01

    A facile approach of fabricating homogeneous graphene oxide (GO)-wrapped Bi2WO6 microspheres (GO/Bi2WO6) is developed. The transmission electron microscopy (TEM) results show that a heterojunction interface between GO and Bi2WO6. The UV-vis diffuse reflection spectra (DRS) reveal that the as-prepared GO/Bi2WO6 composites own more intensive absorption in the visible light range compared with pure Bi2WO6. These characteristic structural and optical properties endow GO/Bi2WO6 composites with enhanced photocatalytic activity. The enhanced photocatalytic activity of the GO/Bi2WO6 is attributed predominantly to the synergetic effect between GO and Bi2WO6, causing rapid generation and separation of photo-generated charge carriers.

  11. The Effect of Microclimates in the Aeolian Sand Environment at the Mogao Grottoes, China

    Directory of Open Access Journals (Sweden)

    Guo Shuai Li

    2013-01-01

    Full Text Available To study the micro-meteorological effects of different underlying surfaces of structures to protect the Mogao Grottoes, we analyzed basic meteorological measurements collected at weather stations located in front of the grottoes, on top of the grottoes and in the artificial Gobi. The results show that the shelterbelts in front of the grottoes have a heat-retaining effect. The profile of average daily solar radiation in front of the grottoes forms a sharp peak and the profile in the Gobi forms a parabola, but these patterns vary in different seasons. The artificial Gobi was more susceptible to extremes in temperature and had a faster response and wider response range to ground temperature. The average monthly air temperature, average monthly relative humidity, and the average wind speed in the artificial Gobi tend to first decrease and then increase with measurement height.

  12. African Journal of Marine Science - Vol 33, No 1 (2011)

    African Journals Online (AJOL)

    ... area between western and eastern Mediterranean basins (Siculo-Tunisian Strait) ... Cross-shelf observations of diet and diel feeding behaviour of the bearded goby ... WHH Sauer, W Potts, D Raberinary, J Anderson, MJ Sylvio Perrine.

  13. Novelty versus environment: two viewpoints on the same phenomenon?

    Czech Academy of Sciences Publication Activity Database

    Janáč, Michal; Konečná, Markéta; Roche, Kevin Francis; Jurajda, Pavel

    2016-01-01

    Roč. 25, č. 4 (2016), s. 678-681 ISSN 0906-6691 Institutional support: RVO:68081766 Keywords : Neogobius melanostomus * Round goby * formalin Subject RIV: EG - Zoology Impact factor: 2.054, year: 2016

  14. Fish, Actinopterygii, Perciformes, Gobiidae, Amblyeleotris rubrimarginata Mohlmann and Randall, 2002: Range gap filled in northern Borneo

    OpenAIRE

    Townsend, D.

    2010-01-01

    The present work reports the shrimp goby Amblyeleotris rubrimarginata Mohlmann and Randall, 2002 in coralsand habitats off three different islands within the Tunku Abdul Rahman marine Park (TARP) off western Sabah in northernBorneo.

  15. Fish, Actinopterygii, Perciformes, Gobiidae, Amblyeleotris rubrimarginata Mohlmann and Randall, 2002: range gap filled in northern Borneo

    OpenAIRE

    Townsend, Ditch

    2010-01-01

    The present work reports the shrimp goby Amblyeleotris rubrimarginata Mohlmann and Randall, 2002 in coral sand habitats off three different islands within the Tunku Abdul Rahman marine Park (TARP) off western Sabah in northern Borneo.

  16. An evaluation of the national measles vaccination campaign in the ...

    African Journals Online (AJOL)

    1991-04-20

    Apr 20, 1991 ... sustained among Transkei-born children. Significant deter- ... a scale to assess the effect on specific urbanising communities. The planned ..... (GOBI-FFF) have demonstrated, this is not Utopian fantasy. On the contrary, a ...

  17. An eDNA Assay to Monitor a Globally Invasive Fish Species from Flowing Freshwater.

    Science.gov (United States)

    Adrian-Kalchhauser, Irene; Burkhardt-Holm, Patricia

    2016-01-01

    Ponto-Caspian gobies are a flock of five invasive fish species that have colonized freshwaters and brackish waters in Europe and North America. One of them, the round goby Neogobius melanostomus, figures among the 100 worst invaders in Europe. Current methods to detect the presence of Ponto-Caspian gobies involve catching or sighting the fish. These approaches are labor intense and not very sensitive. Consequently, populations are usually detected only when they have reached high densities and when management or containment efforts are futile. To improve monitoring, we developed an assay based on the detection of DNA traces (environmental DNA, or eDNA) of Ponto-Caspian gobies in river water. The assay specifically detects invasive goby DNA and does not react to any native fish species. We apply the assay to environmental samples and demonstrate that parameters such as sampling depth, sampling location, extraction protocol, PCR protocol and PCR inhibition greatly impact detection. We further successfully outline the invasion front of Ponto-Caspian gobies in a large river, the High Rhine in Switzerland, and thus demonstrate the applicability of the assay to lotic environments. The eDNA assay requires less time, equipment, manpower, skills, and financial resources than the conventional monitoring methods such as electrofishing, angling or diving. Samples can be taken by untrained individuals, and the assay can be performed by any molecular biologist on a conventional PCR machine. Therefore, this assay enables environment managers to map invaded areas independently of fishermen's' reports and fish community monitorings.

  18. Dicty_cDB: VHF408 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available MTYF9_FA... 33 7.5 CP000568_3082( CP000568 |pid:none) Clostridium thermocellum ATCC 2... 33 9.8 AY698035_1(... AY698035 |pid:none) Desmognathus marmoratus isolate 69... 33 9.8 protein update 2009. 3. 3 PSORT psg: 0.69

  19. Dicty_cDB: VHH521 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available d:none) Clostridium thermocellum ATCC 2... 34 4.9 AY698035_1( AY698035 |pid:none) Desmog...moso... 33 8.4 AY612344_1( AY612344 |pid:none) Desmognathus marmoratus voucher KH... 33 8.4 protein update 2

  20. Northwest Forest Plan—the first 10 years (1994-2003): status and trends of populations and nesting habitat for the marbled murrelet.

    Science.gov (United States)

    Mark H. Huff; Martin G. Raphael; Sherri L. Miller; S. Kim Nelson; Jim Baldwin

    2006-01-01

    The Northwest Forest Plan (the Plan) is a large-scale ecosystem management plan for federal land in the Pacific Northwest. Marbled murrelet (Brachyramphus marmoratus) populations and habitat were monitored to evaluate effectiveness of the Plan. The chapters in this volume summarize information on marbled murrelet ecology and present the monitoring...

  1. Surveying marbled murrelets at inland forested sites: a guide

    Science.gov (United States)

    Peter W.C. Paton; C. John Ralph; Harry R. Carter; S. Kim Nelson

    1990-01-01

    The marbled murrelet (Brachyramphus marmoratus), a seabird, nests in forested stands from southeast Alaska south to Santa Cruz, California. Because of this species' close association with old-growth forests, researchers and land managers need a method to assess murrelet distribution and use patterns throughout its range. This guide describes a...

  2. Declining Marbled Murrelet density, but not productivity, in the San Juan Islands, Washington, USA

    Science.gov (United States)

    Teresa J. Lorenz; Martin G. Raphael

    2018-01-01

    The Marbled Murrelet (Brachyramphus marmoratus) is federally threatened in part of its range in western North America. Information on density and productivity is important for managing populations. Over an 18-yr period, we monitored murrelet density and productivity ratios during the breeding season along 170 km of shoreline of the San Juan Islands...

  3. Logistic regression accuracy across different spatial and temporal scales for a wide-ranging species, the marbled murrelet

    Science.gov (United States)

    Carolyn B. Meyer; Sherri L. Miller; C. John Ralph

    2004-01-01

    The scale at which habitat variables are measured affects the accuracy of resource selection functions in predicting animal use of sites. We used logistic regression models for a wide-ranging species, the marbled murrelet, (Brachyramphus marmoratus) in a large region in California to address how much changing the spatial or temporal scale of...

  4. An annotated checklist of the lizards of French Guiana, mainly based on two recent collections

    NARCIS (Netherlands)

    Hoogmoed, M.S.; Lescure, J.

    1975-01-01

    At the moment 36 species of lizards (6 Gekkonidae, 12 Iguanidae, 1 Scincidae and 17 Teiidae) are known for certain to occur in French Guiana. Of these 36 species, four are reported from that country for the first time (Anolis marmoratus speciosus Garman, Cercosaura o. ocellata Wagler, Prionodactylus

  5. [Dietary composition and food competition of six main fish species in rocky reef habitat off Gouqi Island].

    Science.gov (United States)

    Wang, Kai; Zhang, Shou-Yu; Wang, Zhen-Hua; Zhao, Jing; Xu, Min; Lin, Jun

    2012-02-01

    Based on the monthly investigation data of fish resources in the rocky reef habitat off Gouqi Island from March 2009 to February 2010, this paper studied the dietary composition of three native fish species (Sebasticus marmoratus, Hexagrammos otakii and Hexagrammos agrammus) and three non-native fish species (Lateolabrax japonica, Nibea albiflora and Larimichthys polyactis). The analysis of gut content indicated that the main prey items of these six dominant fish species were Caprellidae, Gammaridea, juvenile S. marmoratus, Engraulis japonicas and Acetes chinensis and the dietary composition of each of the 6 fish species had obvious seasonal variation. There was an intense food competition between native species H. otakii and H. agrammus in autumn, between non-native species N. albiflora and L. polyactis in summer, between non-native species N. albiflora and native species S. marmoratus in autumn, and between non-native species N. albiflora and native species H. otakii in winter. It was suggested the non-native species N. albiflora was the key species in the food competition among the six dominant fish species in this rocky reef habitat, and thus the feeding behaviors of these six fish species could have definite effects on the resource capacity of juvenile S. marmoratus.

  6. Chapter 22: Marbled Murrelet Food Habits and Prey Ecology

    Science.gov (United States)

    Esther E. Burkett

    1995-01-01

    Information on food habits of the Marbled Murrelet (Brachyramphus marmoratus) was compiled from systematic studies and anecdotal reports from Alaska to California. Major differences between the winter and summer diets were apparent, with euphausiids and mysids becoming more dominant during winter and spring. The primary invertebrate prey items were...

  7. Meeting reproductive demands in a dynamic upwelling system: foraging strategies of a pursuit-diving seabird, the marbled murrelet

    Science.gov (United States)

    M. Zachariah Peery; Scott H. Newman; Curt D. Storlazzi; Steven R. Beissinger

    2009-01-01

    Seabirds maintain plasticity in their foraging behavior to cope with energy demands and foraging constraints that vary over the reproductive cycle, but behavioral studies comparing breeding and nonbreeding individuals are rare. Here we characterize how Marbled Murrelets (Brachyramphus marmoratus) adjust their foraging effort in response to changes...

  8. The structure of the nasal chemosensory system in squamate ...

    Indian Academy of Sciences (India)

    This study examined the extent and morphology of the main olfactory organ in several Australian squamate reptiles, including three species of gekkotans, two species of skinks and one snake species. The olfactory mucosa of two gekkotan species (Christinus marmoratus and Strophurus intermedius) is spread over a large ...

  9. Low breeding propensity and wide-ranging movements by marbled murrelets in Washington

    Science.gov (United States)

    Teresa J. Lorenz; Martin G. Raphael; Thomas D. Bloxton; Patrick G. Cunningham

    2016-01-01

    The marbled murrelet (Brachyramphus marmoratus) is a threatened seabird that forages in nearshore marine waters but nests inland, commonly in older coniferous forests. Information on ranging behavior and breeding propensity can be useful for informing management, especially when comparisons can be made between declining or threatened populations...

  10. Chapter 36: Status of Forest Habitat of the Marbled Murrelet

    Science.gov (United States)

    David A. Perry

    1995-01-01

    Marbled Murrelets (Brachyramphus marmoratus) have been shown to be dependant upon old-growth forests for nesting habitat. These forests have declined over the last century as they are cut for human use. This paper reviews the current status of old-growth forests along the west coast, in both the United States and Canada.

  11. Microhabitat Association of Cryptobenthic Reef Fishes (Teleostei: Gobiidae) in the Central Red Sea

    KAUST Repository

    Troyer, Emily

    2018-05-01

    Knowledge of biodiversity within an ecosystem is essential when trying to understand the function and importance of that ecosystem. A challenge when assessing biodiversity of reef habitats is cryptobenthic fishes, which encompass many groups that have close associations with the substrate. These fishes can be behaviorally cryptic, by seeking refuge within the reef matrix, or visually cryptic, using cryptic coloration to match the surrounding habitat. These factors make visual surveys inadequate for sampling these fishes. One such group of cryptobenthic fishes are the gobies, family Gobiidae, which currently represent over 1600 species, although new species are continually being discovered. Gobies are often small (less than 5 cm), and many species will be associated with a very specific microhabitat type. Due to the understudied nature of the Red Sea, little is known about habitat preferences of gobies within the region. In order to determine the differences in goby community structure within the central Red Sea, fishes were sampled at one reef using 1 m² enclosed rotenone stations from three distinct microhabitats: hard coral, rubble, and sand. Following collection, specimens were photographed and sequenced using COI, to aid in species identification. 232 individuals were collected representing 31 species of goby. Rubble microhabitats were found to host the majority of collected gobies (69%), followed by hard coral (20.6%), then sand (9.9%). Goby assemblages in the three microhabitats were significantly different from each other, and evidence of habitat-specialists was found. These results provide essential baseline information about the ecology of understudied cryptobenthic fishes that can be used in future large-scale studies in the Red Sea region.

  12. Gut content analysis of Lake Michigan waterbirds in years with avian botulism type E mortality, 2010–2012

    Science.gov (United States)

    Essian, David A.; Chipault, Jennifer G.; Lafrancois, Brenda M.; Leonard, Jill B.K.

    2016-01-01

    Waterbird die-offs caused by Clostridium botulinum neurotoxin type E (BoNT/E) have occurred sporadically in the Great Lakes since the late 1960s, with a recent pulse starting in the late 1990s. In recent die-offs, round gobies (Neogobius melanostomus) have been implicated as vectors for the transfer of BoNT/E to fish-eating birds due to the round goby invasion history and their importance as prey. Dreissenid mussels (Dreissena spp.) are also potentially involved in BoNT/E transmission to birds and round gobies. We examined gut contents of waterbirds collected in Lake Michigan during die-offs in 2010–2012, and the gut contents of culled, presumably BoNT/E-free double-crested cormorants (Phalacrocorax auritus). Round gobies were found in 86% of the BoNT/E-positive individuals, 84% of the BoNT/E-negative birds, and 94% of the BoNT/E-free cormorants examined. Double-crested cormorants, ring-billed gulls (Larus delewarensis), and common loons (Gavia immer) consumed larger-sized round gobies than horned and red-necked grebes (Podiceps auritus and Podiceps grisegena), white-winged scoters (Melanitta deglandi), and long-tailed ducks (Clangula hymealis). Other common prey included dreissenid mussels, terrestrial insects, and alewives (Alosa pseudoharengus). Our data emphasize the importance of round gobies and mussels in diets of Lake Michigan waterbirds and suggest they may play a role in the transfer of BoNT/E to waterbirds; however, round gobies and mussels were found in BoNT/E-positive, -negative, and -free individuals, suggesting that other factors, such as alternative trophic pathways for toxin transfer, bird migratory timing and feeding locations, prey behavior, and individual physiological differences across birds may affect the likelihood that a bird will succumb to BoNT/E intoxication.

  13. Correlation and Fishers’ Perception in Selected Sites in Laguna de Bay, Luzon Island, Philippines

    Directory of Open Access Journals (Sweden)

    Arthur J. Lagbas

    2017-01-01

    Full Text Available White goby (Glossogobius giuris Hamilton 1822 is an omnivorous, native fish species which can be found in Laguna de Bay and its tributaries, and in other bodies of water in the Philippines. Deteriorating water quality, unsustainable fishing practices, aquaculture and predation by introduced invasive species are threatening the population of white goby and other native fish species in Laguna de Bay. This study was conducted to correlate select physico-chemical parameters of lake water and zooplankton abundance, and to assess white goby population based on fishers’ perception. Water samples were collected in three sites in June, September and December 2014. Twenty one zooplankton species belonging to 12 families were identified. The most abundant and frequently encountered zooplankton species is Eurytemora affinis Poppe 1880. Zooplanktons were most abundant in June and lowest in September. Key informant interviews with local fishers revealed that white goby population was abundant in April to August while catch report showed that fish catch is abundant in June and least during December. The fish abundance in April to June could be attributed to high productivity especially in summer season. The fishers perceived that the population of white goby was declining mainly due to water pollution, aquaculture, and predation by invasive alien species. A multi-stakeholder sustainable watershed management should be adapted to improve the water quality and extinction of native fish species in Laguna de Bay.

  14. A Field Observation of Rotational Feeding by Neogobius melanostomus

    Directory of Open Access Journals (Sweden)

    Ted R. Angradi

    2018-01-01

    Full Text Available Neogobius melanostomus, the round goby, was recorded by underwater video feeding on crushed dreissenid mussels at a depth of 12 m in Georgian Bay of Lake Huron, a Laurentian Great Lake. In the video, gobies used rotational or twist feeding to tear away particles from crushed mussels. At least 43 examples of this feeding maneuver occur in the video. Up to 120 gobies m−2 were visible at a time in the video. Mean standard length of gobies appearing in the video was 37 mm. Mean standard length of fish exhibiting twist feeding was larger, 48 mm. Mean size of intact mussels in visible clusters was about 10 × 20 mm, a size which exceeds the gape width of the largest gobies observed in the video. Neogobius melanostomus is known to use twisting to wrest small attached mussels from the substrates which can be crushed by their pharyngeal teeth. I surmise that the behavior observed in the video is an opportunistic manifestation of this inherent behavioral adaptation to overcome gap limitation and exploit a temporary windfall of food.

  15. Otoliths as an integral part in fossil fish taxonomy

    Directory of Open Access Journals (Sweden)

    Christoph Gierl

    2015-11-01

    Full Text Available Otoliths are small structures in the skull of fishes. They are responsible for hearing and orientation in the 3-dimensional space. They also hold valuable information regarding the taxonomy. Their outline, the shape of the sulcus and other features allow the determination of a fish even to the species level. A lot of fossil species are solely based on otoliths because of their good chance of preservation. Gobies are in this case no different. An additional challenge in gobies is their high similarity between species concerning the preservable parts. Fossil skeletons that are 20 Million years old can show only few differences compared to recent gobies. These features are often hardly recognizable due to their preservation. As a consequence many fossil gobies have been assigned to the genus Gobius sensu lato. Examples are two gobies from the Miocene of Southern Germany. They have a unique combination of characters (six branchiostegals, palatine resembling a “T”, no entopterygoid that allows the rectification of a new fossil genus but the two species are hardly distinguishable based only on the skeleton. The key hints in having two species are the otoliths. They show slight but consistent differences in their outline. This shows that otoliths can be a key feature in species identification. They should also be taken into consideration by recent fish species. Not to mention their possible phylogenetic potential that remains to be explored.

  16. Species composition and dietary relationships in a brackish shallow water fish assemblage in the Bothnian Sea, Sweden

    Science.gov (United States)

    Thorman, Staffan; Wiederholm, Anne-Marie

    1984-09-01

    A nearshore fish assemblage inhabiting a shallow bay in the southern Bothnian Sea, Sweden, with demanding environmental conditions (c. 5‰; >15°C during 4 months 1980 and 1 month 1981) was studied during a two-year period, in 1980 and 1981. Seasonal distribution patterns, dietary relationships, and growth rates were studied in Pungitius pungitius (L.), Pomatoschistus minutus (Pallas.), Gasterosteus aculeatus (L.), Phoxinus phoxinus (L.), Pomatoschistus microps (Krøyer) and Gobius niger L. The structure of the juvenile populations changed both over seasons and years but the adult populations remained constant. Lower water temperature, fewer individuals, lower and delayed fish growth, and lower interspecific food overlaps were found in 1981 compared to 1980. Few significant correlations were found in both years between the following community parameters: diversity, niche width, food overlap, and the proportion of each species in the fish assemblage. According to these results it is suggested that food competition and resource partitioning were of minor importance for the structuring of the fish community in the present area. Rather, the extreme salinity and the fluctuations in temperature regulated the fish populations. One may conclude that the populations of juveniles were more influenced by short-term changes in the environment than those of the adults.

  17. Vertical patterns of ichthyoplankton at the interface between a temperate estuary and adjacent coastal waters: Seasonal relation to diel and tidal cycles

    Science.gov (United States)

    Primo, Ana Lígia; Azeiteiro, Ulisses M.; Marques, Sónia C.; Ré, Pedro; Pardal, Miguel A.

    2012-07-01

    Vertical distribution and migration pattern of ichthyoplankton assemblage in the Mondego estuary were investigated in relation to diel and tidal cycle. Summer and winter communities were sampled, at surface and bottom, over a diel cycle during spring and neap tides at a fixed station at the mouth of the estuary. Summer presented higher larvae density mainly of Pomatoschistus spp., Gobius niger and Parablennius pilicornis. Main species in winter assemblages were Pomatoschistus spp. and Sardina pilchardus. There were no differences between depth stratums across diel or tide cycle. Nevertheless, main species larval densities showed significant periodic variation associated with tide (M2) and diel (K1) cycles presenting generally, higher density at night and around low tide. Conversely, vertical patterns observed could not be related with diel or tidal cycle. Tough, main species presented some extent of vertical migration. Vertical patterns observed appear to be related to seasonal stratification and river flow, increasing amplitude during periods of less stratification and lower water currents. Present study provides a better understanding of ichthyoplankton vertical movement patterns and of small scale dynamics at the interface of two coastal European systems.

  18. Estado de las poblaciones de anfibios en un parque urbano de Pamplona

    Directory of Open Access Journals (Sweden)

    Gosá, A., Arias, A.

    2009-01-01

    Full Text Available Las poblaciones aisladas de tres anfibios (Triturus marmoratus, Alytes obstetricans, Pelophylax perezi han sido muestreadas entre 2005 y 2007, en primavera y finales de verano, en un canal y tres estanques de un parque urbano céntrico de la ciudad de Pamplona. Los 8 adultos censados en 2005 de T. marmoratus han podido desaparecer en los años siguientes, a causa de unas obras urbanas realizadas junto al parque. La estima de la población de A. obstetricans se acerca al millar de adultos. Su periodo reproductor se extiende hasta septiembre, y una parte de la población larvaria inverna sin metamorfosear. El ajardinamiento de la zona, la contaminación del agua y la presencia de depredadores y competidores introducidos, como Procambarus clarkii y Carassius auratus, ponen en peligro la supervivencia de los anfibios.

  19. Life cycle assessment and evaluation of energy payback time on high-concentration photovoltaic power generation system

    International Nuclear Information System (INIS)

    Nishimura, A.; Hayashi, Y.; Tanaka, K.; Hirota, M.; Kato, S.; Ito, M.; Araki, K.; Hu, E.J.

    2010-01-01

    In this study, the environmental load of photovoltaic power generation system (PV) during its life cycle and energy payback time (EPT) are evaluated by LCA scheme. Two hypothetical case studies in Toyohashi, Japan and Gobi dessert in China have been carried out to investigate the influence of installation location and PV type on environmental load and EPT. The environmental load and EPT of a high-concentration photovoltaic power generation system (hcpV) and a multi-crystalline silicon photovoltaic power generation system (mc-Si PV) are studied. The study shows for a PV of 100 MW size, the total impacts of the hcpV installed in Toyohashi is larger than that of the hcpV installed in Gobi desert by 5% without consideration of recycling stage. The EPT of the hcpV assumed to be installed in Gobi desert is shorter than EPT of the hcpV assumed to be installed in Toyohashi by 0.64 year. From these results, the superiority to install PV in Gobi desert is certificated. Comparing with hcpV and mc-Si PV, the ratio of the total impacts of mc-Si PV to that of hcpV is 0.34 without consideration of recycling stage. The EPT of hcpV is longer than EPT of mc-Si PV by 0.27 year. The amount of global solar radiation contributing to the amount of power generation of mc-Si PV is larger than the amount of direct solar radiation contributing to the amount of power generation of hcpV by about 188 kW h/(m 2 year) in Gobi desert. Consequently, it appears that using mc-Si PV in Gobi desert is the best option.

  20. The distribution of 4-nonylphenol in marine organisms of North American Pacific Coast estuaries.

    Science.gov (United States)

    Diehl, Jennifer; Johnson, Sarah E; Xia, Kang; West, Amy; Tomanek, Lars

    2012-04-01

    One of the chemical breakdown products of nonylphenol ethoxylates, 4-nonylphenol (4-NP), accumulates in organisms and is of concern as an environmental pollutant due to its endocrine disrupting effects. We measured 4-NP levels in the seawater, sediment, and twelve organisms within the California estuary, Morro Bay, and examined biomagnification of 4-NP using stable isotope abundances (δ(15)N and δ(13)C) to quantify trophic position. 4-NP concentrations in organisms from Morro Bay included 25000±8600 ng g(-1) lw in liver of California sea lion, 14000±5600 ng g(-1) lw in liver of harbor porpoise, 138000±55000 ng g(-1) lw in liver of sea otters, 15700±3600 ng g(-1) lw in liver of seabirds, 36100±6100 ng g(-1) lw in arrow goby fish, 62800±28400 ng g(-1) lw in oysters, and 12700±1300 ng g(-1) lw in mussels. 4-NP levels generally showed a pattern of trophic dilution among organisms in Morro Bay, with exceptions of biomagnification observed between three trophic links: mussel to sea otter (BMF 10.9), oyster to sea otter (BMF 2.2), and arrow goby to staghorn sculpin (BMF 2.7). Our examination of other west coast estuaries of USA and Canada revealed that mean 4-NP concentrations in gobies and mussels from Morro Bay were significantly higher than those from a more urbanized estuary, San Francisco Bay (goby: 11100±3800 ng g(-1) lw) and from a remote estuary, Bamfield Inlet, Canada (goby: 9000±900 ng g(-1) lw, mussel: 6100±700 ng g(-1) lw). Relative to other estuaries worldwide, 4-NP levels in seawater (0.42±0.16 μg L(-1)) and sediment (53±14 ng g(-1) dw) of Morro Bay are low, but gobies and oysters have higher 4-NP levels than comparable fauna. Copyright © 2012 Elsevier Ltd. All rights reserved.

  1. Factors affecting numbers of Culicoides in truck traps in coastal Queensland.

    Science.gov (United States)

    Kettle, D S; Edwards, P B; Barnes, A

    1998-10-01

    Truck trap collections of Ceratopogonidae were made over a period of 27 months (November 1973-February 1976) at Tingalpa Creek, in southeast Queensland, Australia. Six collections were made on each of 95 days, giving 570 observations and a total of 29,378 Culicoides. Two collections were made before, one at, and three after sunset. Separate analyses were made of the catches of thirteen entities: male and female C. austropalpalis, C. brevitarsis, C. marksi, C. marmoratus and C. victoriae, female C. henryi and C. longior, and total C. bundyensis. Catches were dominated by C. brevitarsis (35.2%) and C. marmoratus (32.3%) and, with C. victoriae, were taken on almost every collecting day over all seasons. Sex ratios (M:F) varied from 0:100 for C. longior to 130:100 for C. marksi. Collections of all entities, except female C. henryi, were greatest (50-70% of the daily catch) at sunset. In winter there was substantial activity in the hour before sunset. Time of day was the most important variable, accounting for 15-45% of the observed variation. Between-day differences were significant for all except C. austropalpalis, C. victoriae and male C. marksi. Culicoides brevitarsis, C. bundyensis and C. longior had highly significant annual cycles, C. victoriae and female C. austropalpalis had significant lunar cycles, and C. longior had a significant tidal cycle. Logarithms of catches of female C. austropalpalis, C. brevitarsis, C. henryi, C. marmoratus, and female and male C. victoriae were inversely related to linear wind speed. Log catches of female C. austropalpalis, C. brevitarsis, C. marmoratus and C. victoriae, and male C. marksi and C. victoriae were positively related to temperature (quadratic).

  2. Pardaxin permeabilizes vesicles more efficiently by pore formation than by disruption

    DEFF Research Database (Denmark)

    Vad, Brian S; Bertelsen, Kresten; Johansen, Charlotte Hau

    2010-01-01

    Pardaxin is a 33-amino-acid neurotoxin from the Red Sea Moses sole Pardachirus marmoratus, whose mode of action shows remarkable sensitivity to lipid chain length and charge, although the effect of pH is unclear. Here we combine optical spectroscopy and dye release experiments with laser scanning...... is more efficient than lysis of anionic vesicles, suggesting that electrostatic interactions may trap pardaxin in several suboptimal interconverting conformations on the membrane surface....

  3. Karyotypic similarities between two species of Rhamphichthys (Rhamphichthyidae, Gymnotiformes from the Amazon basin

    Directory of Open Access Journals (Sweden)

    Patrícia Silva

    2013-10-01

    Full Text Available The family Rhamphichthyidae includes three genera: Rhamphichthys Müller et Troschel, 1846, Gymnorhamphichthys M. M. Ellis, 1912 and Iracema Triques, 1996. From this family, only the species Rhamphichthys hanni Meinken, 1937 has had its karyotype described. Here, we describe the karyotypes of two additional Rhamphichthys species: R. marmoratus Castelnau, 1855 from the Reserva de Desenvolvimento Sustentável Mamirauá, Amazonas state and R. prope rostratus Linnaeus, 1766 from Pará state, both in Brazil. Our karyotypic analyses demonstrated that the diploid number is conserved for the genus (2n = 50, but the karyotypic formulas (KFs differed between R. marmoratus (44m/sm+6a and R. prope rostratus (42m/sm+8a. In both species, the constitutive heterochromatin (CH was located in the centromeric region of most chromosomes. Large heterochromatic blocks were found on the long arms of pairs 4 and 14 in R. marmoratus and on chromosomes 3, 4 and 19 in R. prope rostratus, which also has a heteromorphism in chromosome pair 1. The CH was DAPI positive, indicating that it is rich in AT base pairs. The Nucleolus Organizer Region (NOR showed staining at a single location in both species: the long arm of pair 1 in R. marmoratus and the long arm of pair 12 in R. prope rostratus, where it showed a size heteromorphism. CMA3 staining coincided with that of Ag-NOR, indicating that the ribosomal genes contain interspaced GC-rich sequences. FISH with an 18S rDNA probe confirmed that there is only one NOR site in each species. These results can be used as potential cytogenetic markers for fish populations, and comparative analysis of the karyotypes of Hypopygus Hoedman, 1962, Rhamphichthys and Steatogenys Boulenger, 1898 suggests that the first two genera diverged later that the third.

  4. Oxygen drives skeletal muscle remodeling in an amphibious fish out of water.

    Science.gov (United States)

    Rossi, Giulia S; Turko, Andy J; Wright, Patricia A

    2018-04-24

    Skeletal muscle remodeling in response to terrestrial acclimation improves the locomotor performance of some amphibious fishes on land, but the cue for this remodeling is unknown. We tested the hypothesis that muscle remodeling in the amphibious Kryptolebias marmoratus on land is driven by higher O 2 availability in atmospheric air, and the alternative hypothesis that remodeling is induced by a different environmental or physiological condition fish experience on land. Fish were acclimated to 28 days of air, aquatic hyperoxia, hypercapnia, hypoxia, elevated temperature, or fasting conditions. Air, fasting, and hyperoxic conditions increased (>25%) the size of oxidative fibers in K. marmoratus while hypoxia had the reverse effect (23% decrease). Surprisingly, hyperoxia-acclimation also resulted in a transformation of the musculature to include large bands of oxidative-like muscle. Our results show that K. marmoratus is highly responsive to environmental O 2 levels and capitalize on O 2 -rich opportunities to enhance O 2 utilization by skeletal muscle. © 2018. Published by The Company of Biologists Ltd.

  5. Why are marine adaptive radiations rare in Hawai'i?

    Science.gov (United States)

    Wainwright, Peter C

    2015-02-01

    Islands can be sites of dynamic evolutionary radiations, and the Hawaiian Islands have certainly given us a bounty of insights into the processes and mechanisms of diversification. Adaptive radiations in silverswords and honeycreepers have inspired a generation of biologists with evidence of rapid diversification that resulted in exceptional levels of ecological and morphological diversity. In this issue of Molecular Ecology, tiny waterfall-climbing gobies make a case for their place among Hawaiian evolutionary elite. Moody et al. (2015) present an analysis of gene flow and local adaptation in six goby populations on Kaua'i and Hawai'i measured in three consecutive years to try to disentangle the relative role of local adaptation and gene flow in shaping diversity within Sicyopterus stimpsoni. Their study shows that strong patterns of local selection result in streams with gobies adapted to local conditions in spite of high rates of gene flow between stream populations and no evidence for significant genetic population structure. These results help us understand how local adaptation and gene flow are balanced in gobies, but these fishes also offer themselves as a model that illustrates why adaptive diversification in Hawai'i's marine fauna is so different from the terrestrial fauna. © 2015 John Wiley & Sons Ltd.

  6. Final Supplemental Environmental Assessment: Falcon I Launch Vehicle Program from SLC-4W Vandenberg Air Force Base, California

    Science.gov (United States)

    2005-09-06

    affected surface water, 3) adversely affected groundwater quantity or quality, or 4) caused a need that exceeded the existing potable supply or...goby is from Tillas Slough (mouth of the Smith River) in Del Norte County, south to Colonel Louis D. Van Mullem, Jr. (1-8-96-F/C-29) 5 Agua Hedionda

  7. Is the osmorespiratory compromise limiting invasive species?

    DEFF Research Database (Denmark)

    Ferreira, Patricia Gomes; Flavio, Hugo; Hacking, Harry

    The round goby (Neogobius melanostomus) is a benthic fish native to the brackish waters of the Black and Caspian Seas; however, it has invaded several brackish and freshwater areas in North America and northern Europe. Notably, there are no records of N. melanostomus in high salinity marine habit...

  8. 76 FR 3069 - Endangered and Threatened Wildlife and Plants; 90-Day Finding on a Petition To Delist or...

    Science.gov (United States)

    2011-01-19

    ... feeding, breeding, and sheltering; (b) Genetics and taxonomy; (c) Historical and current range, including..., and the tidewater goby. Petition History On May 18, 2010, we received a petition dated May 13, 2010... be deferred until taxonomic research referred to in the Genetics section of the 2007 5-year review...

  9. Characteristics of trophic transfer of polychlorinated biphenyls in marine organisms in Incheon North Harbor, Korea.

    Science.gov (United States)

    Kim, Seung Kyu; Lee, Dong Soo; Oh, Jae Ryong

    2002-04-01

    The trophic transfer of polychlorinated biphenyls (PCBs) was characterized for zooplankton (primarily Paracalanus spp. and Acartia spp.), pacific oyster (Crassostrea gigas), shore crab (Hemigrapsus penicillatus), and goby (Acanthogobius hasta) in the aquatic system of Incheon North Harbor, Korea. The congener pattern in the species was clearly divided by the main PCB uptake route. Compared with zooplankton and oyster, the fraction of heavier homologues increased in crab and goby that take PCBs from food. Linear relationships were observed between log (fugacity in lipid/fugacity in seawater) and log Kow for all the species. For zooplankton and oyster, such an observation should not be regarded as a true absence of superhydrophobicity, because establishment of equilibrium with seawater was not evident. For crab and goby, the absence of superhydrophobicity was evidenced by the trophic transfer factor that continuously increased with Kow up to 10(7.8). These results suggest that superhydrophobicity might be species specific. The trophic transfer factors and the fugacity levels in the lipid phase indicated that bioaccumulation in crab and goby advanced beyond the level in equilibrium with seawater in the harbor basin.

  10. The Modulation of Fibrosis In Scleroderma by 3-Deoxyglucosone

    Science.gov (United States)

    2011-06-01

    24 h . . RNA was extracted and quantitative real-time PCR was performed for the GObi AI transcript. Transcript levels were normalized to !3-actin. AJI ... Red X denotes the negative effect of 3DG-collagen on that pathway. 54 55 Reference List (1) Kessler D, Dethlefsen S, Haase I, Plomann M

  11. 77 FR 43222 - Endangered and Threatened Wildlife and Plants; Designation of Critical Habitat for the Tidewater...

    Science.gov (United States)

    2012-07-24

    ... proposed in critical habitat unit MAR-5 Bolinas Lagoon and SLO-12 Oso Flaco Lake, as well as additional surveying for tidewater goby in Oso Flaco Lake. As we stated earlier, we are soliciting data and comments... Lagoon, SLO-1 Arroyo de la Cruz, SLO-12 Oso Flaco Lake, LA-1 Arroyo Sequit, and LA-2 Zuma Canyon. These...

  12. Gyrodactylus proterorhini in its non-native range: distribution and ability to host-switch in freshwaters

    Czech Academy of Sciences Publication Activity Database

    Ondračková, Markéta

    2016-01-01

    Roč. 115, č. 8 (2016), s. 3153-3162 ISSN 0932-0113 R&D Projects: GA ČR(CZ) GAP505/12/2569 Institutional support: RVO:68081766 Keywords : Gobies * Gyrodactylidae * Introduction * Ponto-Caspian * Range expansion Subject RIV: EH - Ecology, Behaviour Impact factor: 2.329, year: 2016

  13. NATIVE AND INTRODUCED LARVAL FISHES IN SUISAN MARSH, CALIFORNIA,: THE EFFECTS OF FRESHWATER FLOW

    Science.gov (United States)

    We sampled ichthyoplankton weekly in Suisun Marsh in the San Francisco Estuary from February to June each year from 1994 to 1999. We collected approximately 227,900 fish, predominantly shimofuri goby Tridentiger bifasciatus (60%) and prickly sculpin Cottus asper (33%). Principal ...

  14. Invazní druhy ryb - co o nich víme? Případ hlaváče říčního

    Czech Academy of Sciences Publication Activity Database

    Konečná, Markéta

    2013-01-01

    Roč. 2013, 05 (2013), s. 10-12 R&D Projects: GA ČR(CZ) GAP505/11/1768 Institutional support: RVO:68081766 Keywords : native monkey goby Subject RIV: EG - Zoology https://cs.publero.com/title/vertebratus-cz/5-2013

  15. The community structure of over-wintering larval and small juvenile fish in a large estuary

    DEFF Research Database (Denmark)

    Munk, Peter; Cardinale, Massimiliano; Casini, Michele

    2014-01-01

    and abundances are described, and linkages between ichthyoplankton abundances and corresponding hydrographical information are analysed by GAM methods. Communities were dominated by herring, gobies, butterfish, sprat, pipefishes, lemon sole and European eel (i.e. glass eel), and all the sampled species showed...

  16. 76 FR 64995 - Endangered and Threatened Wildlife and Plants; Designation of Revised Critical Habitat for the...

    Science.gov (United States)

    2011-10-19

    ... do not possess stream channels or tributaries that provide a considerable amount of water throughout... sedimentation of coastal lagoons and riparian habitats, removal of vegetative cover, increased ambient water... channels. As a result, several of the locations occupied by tidewater goby do not contain natural sandbars...

  17. Long-term monitoring of native bullhead and invasive gobiids in the Danubian rip-rap zone

    Czech Academy of Sciences Publication Activity Database

    Janáč, Michal; Roche, Kevin Francis; Šlapanský, Luděk; Polačik, Matej; Jurajda, Pavel

    2018-01-01

    Roč. 807, č. 1 (2018), s. 263-275 ISSN 0018-8158 R&D Projects: GA ČR(CZ) GBP505/12/G112 Institutional support: RVO:68081766 Keywords : Competition * Fish population structure * Invasive species impact * Ponto–Caspian gobies * River bank stabilisation Subject RIV: EG - Zoology Impact factor: 2.056, year: 2016

  18. Climate Change | Page 75 | IDRC - International Development ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Read more about Sri Lanka better prepared for future tsunamis. Language English. Gabin Koto N'Gobi's research focuses on water. But it was the lack of water in the semi-arid northern region of his home country, Benin, which really motivated him. Read more about Every drop counts: Interview with awardee Gabin Koto N' ...

  19. Physical factors affecting the abundance and species richness of fishes in the shallow waters of the southern Bothnian Sea (Sweden)

    Science.gov (United States)

    Thorman, Staffan

    1986-03-01

    The relationship between the composition of the fish assemblages and the abiotic environment in seven shallow areas within the same geographical range in the southern Bothnian Sea were studied in May, July, September and November 1982. Eighteen species were found in the areas and the major species were Pungitius pungitius (L.), Pomatoschistus minutus (Pallas), Gasterosteus aculeatus (L.), Phoxinus phoxinus (L.), Pomatoschistus microps (Krøyer) and Gobius niger L. The main purpose of the study was to examine the possible effects of exposure, organic contents in sediments and habitat heterogeneity on species richness and abundance of the assemblages. There was a negative correlation between the organic contents of the sediment and exposure. There were no significant correlations between exposure, organic contents, size of the areas and species numbers but habitat heterogeneity was positively correlated with species number. There were no correlations between fish abundance and heterogeneity of the areas. Negative correlations occurred between the exposure of the areas and fish abundance. The amounts of the pooled benthic fauna were negatively correlated to the exposure. The species/area hypothesis finds no support in the results, because there was no correlation between habitat heterogeneity of an area and its size. The effective fetch combined with the heterogeneity measurement of the areas seemed to be useful indicators of the species composition and fish abundance. Habitat heterogeneity and exposure were the most important structuring factors of these shallow water fish assemblages during the ice-free period and within the local geographical range. The assemblages consist of a mixture of species with marine or limnic origin and they have probably not evolved in the Bothnian Sea or together. They are most likely regulated by their physiological plasticity and not by interactions with other species.

  20. Seasonal variation of assemblage and feeding guild structure of fish species in a boreal tidal basin

    Science.gov (United States)

    Kellnreitner, Florian; Pockberger, Moritz; Asmus, Harald

    2012-08-01

    Species composition, abundance, feeding relationships and guild structure of the fish assemblage in the Sylt-Rømø bight, a tidal basin in the northern Wadden Sea, were investigated to show seasonal differences and the importance of functional groups in this area. The tidal flats and in shallow subtidal areas were sampled using a beach seine and a bottom trawl net was used for deeper subtidal areas and tidal gullies. Species richness of fish was highest in summer where 26 species were caught, while the lowest richness was recorded in winter (17 species). Clear differences in species richness and abundance were found between shallow areas and deeper parts of the bight. Clupea harengus and Ammodytes tobianus were the most abundant species in deeper areas, while Pomatoschistus microps and Pomatoschistus minutus dominated shallower waters. Gut contents of 27 fish species were identified and the guild structure analyzed by UPGMA clustering of niche overlaps. Calanoid copepods (19.9%), Crangon crangon (18.2%) and mysid shrimps (8.4%) were the most abundant prey items of all fish species combined. Seven feeding guilds were present in the fall and winter, and eight and six in spring and summer, respectively. Fish feeding on calanoid copepods and C. crangon were present year round, whereas the occurrence of other guilds varied between seasons. Species composition of prey changed through seasons and, for some fish species, even the feeding mode itself varied with season. Most noticeable, 11 fish species changed guilds between seasons. We found a convergence in summer towards abundant prey items, whereas in winter diet overlap was lower. This is the first investigation of guild structure of almost all fish species present in a Wadden Sea area, and shows that consideration of seasonal differences is essential when determining feeding relationships of fish in temperate areas.

  1. Pharyngeal cavity and the gills are the target organ for the repellent action of pardaxin in shark.

    Science.gov (United States)

    Primor, N

    1985-05-15

    Pardaxin, an active principle of the repellent secretion of the Red Sea flatfish, Pardachirus marmoratus, elicited severe struggling, mouth paralysis, and transient increase in urea leakage from the gills only when administered to the medium bathing the shark's pharyngeal cavity and gills. An apparatus was constructed which prevents a mixing of the outflow from shark's gills with water bathing its surface skin. It is concluded that in sharks the gills and/or the pharyngeal cavity are the target organ for the repellent action of pardaxin.

  2. Changes in metallothionein concentrations in response to variation in natural factors (salinity, sex, weight) and metal contamination in crabs from a metal-rich estuary.

    Science.gov (United States)

    Legras; Mouneyrac; Amiard; Amiard-Triquet; Rainbow

    2000-04-05

    Intermoult male and female crabs Pachygrapsus marmoratus and Carcinus maenas were sampled from three sites between the mouth and 25 km upstream in the Gironde, the most Cd-contaminated estuary in France, in order to study the relative importance of natural factors (salinity, sex, weight) and accumulated metal concentrations on metallothionein (MT) concentrations. In the two species studied, higher metal, total protein and MT concentrations were observed in the hepatopancreas than in the gills. In P. marmoratus, MT concentrations were mainly related to changes in the natural factors even if MT and Zn concentrations were positively correlated in the hepatopancreas whereas in C. maenas, the main relationships were with accumulated metal levels. In the case of the natural factors, the most important ones were weight in gills of both crab species, and salinity changes in both hepatopancreas and gills of P. marmoratus. Cd and Cu concentrations in both organs of the two species were inversely related to salinity. The same observation was found for Zn concentrations in C. maenas but not in P. marmoratus. In the hepatopancreas of both species, the highest total protein concentrations were found in crabs from the site with the highest salinity, whereas there were no such differences in the gills. It seems that changes in MT concentrations are linked more to changes in general protein metabolism than to changes in metal accumulation. Thus it was important to examine the storage of metals in other tissue compartments, particularly the insoluble fraction which includes mineral granules which is known to also contribute to trace metal detoxification in invertebrates. In the gills of the crabs, Zn was present mainly in the insoluble fraction, whereas Cd was nearly equally distributed between soluble and insoluble fractions. In contrast, Cu in the gills and all three metals in the hepatopancreas of both species were mainly cytosolic, but this does not necessarily imply a

  3. Permanent genetic resources added to Molecular Ecology Resources Database 1 February 2013-31 March 2013.

    Science.gov (United States)

    Arias, M C; Atteke, Christiane; Augusto, S C; Bailey, J; Bazaga, Pilar; Beheregaray, Luciano B; Benoit, Laure; Blatrix, Rumsaïs; Born, Céline; Brito, R M; Chen, Hai-kui; Covarrubias, Sara; de Vega, Clara; Djiéto-Lordon, Champlain; Dubois, Marie-Pierre; Francisco, F O; García, Cristina; Gonçalves, P H P; González, Clementina; Gutiérrez-Rodríguez, Carla; Hammer, Michael P; Herrera, Carlos M; Itoh, H; Kamimura, S; Karaoglu, H; Kojima, S; Li, Shou-Li; Ling, Hannah J; Matos-Maraví, Pável F; McKey, Doyle; Mezui-M'Eko, Judicaël; Ornelas, Juan Francisco; Park, R F; Pozo, María I; Ramula, Satu; Rigueiro, Cristina; Sandoval-Castillo, Jonathan; Santiago, L R; Seino, Miyuki M; Song, Chang-Bing; Takeshima, H; Vasemägi, Anti; Wellings, C R; Yan, Ji; Yu-Zhou, Du; Zhang, Chang-Rong; Zhang, Tian-Yun

    2013-07-01

    This article documents the addition of 142 microsatellite marker loci to the Molecular Ecology Resources database. Loci were developed for the following species: Agriophyllum squarrosum, Amazilia cyanocephala, Batillaria attramentaria, Fungal strain CTeY1 (Ascomycota), Gadopsis marmoratus, Juniperus phoenicea subsp. turbinata, Liriomyza sativae, Lupinus polyphyllus, Metschnikowia reukaufii, Puccinia striiformis and Xylocopa grisescens. These loci were cross-tested on the following species: Amazilia beryllina, Amazilia candida, Amazilia rutila, Amazilia tzacatl, Amazilia violiceps, Amazilia yucatanensis, Campylopterus curvipennis, Cynanthus sordidus, Hylocharis leucotis, Juniperus brevifolia, Juniperus cedrus, Juniperus osteosperma, Juniperus oxycedrus, Juniperus thurifera, Liriomyza bryoniae, Liriomyza chinensis, Liriomyza huidobrensis and Liriomyza trifolii. © 2013 John Wiley & Sons Ltd.

  4. A new Synbranchus (Teleostei: Synbranchiformes: Synbranchidae from ilha de Marajó, Pará, Brazil, with notes on its reproductive biology and larval development

    Directory of Open Access Journals (Sweden)

    Sandra E. Favorito

    Full Text Available Synbranchus lampreia, new species, is described from rio Goiapi, Marajó Island, Pará, northern Brazil. It differs from the other two described species of the genus by its color pattern, which consists of large roundish black blotches scattered over a light brown or yellowish ground pigmentation and presence of inconspicuous brown small spots distributed among the large dark spots. The species is further distinguished from S. marmoratus by a higher number of vertebrae and from S. madeira by a shorter postanal length. Information about reproductive aspects is provided and larval stages are described and illustrated.

  5. Distribución de Sicydium Valenciennes 1837 (Pisces: Gobiidae) en México y Centro América

    OpenAIRE

    Lyons, John

    2005-01-01

    Gobies of the genus Sicydium Valenciennes are widespread in Mexico and Central America, but have a different distribution pattern on the Atlantic and Pacific slopes of the region. On the Pacific slope, where mountain ranges are found near the coast and the coastal plain is narrow, Sicydium is continuously distributed in rivers from Mazatlán, Sinaloa, Mexico, to central Panama. On the Atlantic slope, Sicydium is known from to three disjunct areas where coastal mountain ranges are present, cent...

  6. Unravelling the secret of the resistance of desert strains of Chroococcidiopsis to desiccation and radiation

    OpenAIRE

    Billi, Daniela; Fagliarone; Verseux, Cyprien; Mosca, Claudia; Baqué, Mickael; Wilmotte, Annick

    2017-01-01

    Chroococcidiopsis is a unicellular cyanobacterial genus that is growing in extreme dry conditions, either in low or high temperatures. At the lower end of the spectrum, they live as cryptoendoliths in rocks of the Mc Murdo Dry Valleys in Antarctica where they were discovered by Imre Friedmann, while at the higher end, they grow as hypoliths/endoliths in hot deserts, e.g. Negev, Gobi, Atacama (Friedman, 1980). The capacity of desert strains of Chroococcidiopsis to stabilize their sub-cellul...

  7. A new discovery of Glossopteris in southeastern Mongolia as an argument for distant migration of Gondwanan plants

    Science.gov (United States)

    Naugolnykh, Serge V.; Uranbileg, L.

    2018-04-01

    Well-preserved leaves conforming to the fossil genus Glossopteris are found in the Permian deposits of southeastern Gobi, Khatan-Bulag locality, Mongolia. These leaves have many features in common with Glossopteris communis Feistmantel described from India. The locality Khatan-Bulag belongs to Sulinkheer nappe-fold tectonic megazone. The Glossopteris sp. cf. G. communis specimens from the Khatan-Bulag suggest that there was effective migration gateway between Gondwana and southern regions of Asia in the mid-Permian.

  8. Functional type 2 photosynthetic reaction centers found in the rare bacterial phylum Gemmatimonadetes

    OpenAIRE

    Zeng, Yonghui; Feng, Fuying; Medová, Hana; Dean, Jason; Koblížek, Michal

    2014-01-01

    Photosynthesis is one of the most fundamental biological processes on Earth. To date, species capable of performing (bacterio)chlorophyll-based phototrophy have been reported in six bacterial phyla. Here we report a phototrophic bacterium belonging to the rare and understudied phylum Gemmatimonadetes. This strain, isolated from a freshwater lake in the Gobi Desert, contains fully functional photosynthetic reaction centers. Its photosynthesis genes appear to originate from an ancient horizonta...

  9. Fall diets of red-breasted merganser (Mergus serrator) and walleye (Sander vitreus) in Sandusky Bay and adjacent waters of western Lake Erie

    Science.gov (United States)

    Bur, M.T.; Stapanian, M.A.; Bernhardt, G.; Turner, M.W.

    2008-01-01

    Although published studies indicate the contrary, there is concern among many sport anglers that migrating red-breasted mergansers (Mergus serrator) and other waterbirds pose a competitive threat to sport fish species such as walleye (Sander vitreus) in Lake Erie. We quantified the diet of autumn-migrant mergansers and walleye during 1998-2000 in Sandusky Bay and adjacent waters of western Lake Erie. We hypothesized that the diets of both predators would be similar in species composition, but because of different foraging ecologies their diets would differ markedly in size of prey consumed. In addition to predator samples, we used trawl data from the same general area as an index of prey availability. We found that mergansers fed almost exclusively on fish (nine species). Gizzard shad (Dorosoma cepedianum), emerald shiner (Notropis atherinoides) and round goby (Neogobius melanostomus) were consumed in the greatest numbers, most frequently and comprised the greatest biomass. Walleye fed exclusively on fish: gizzard shad, alewife (Alosa psuedoharengus) and emerald shiner were consumed in the greatest numbers, most frequently and comprised the greatest biomass. Diet overlap between mergansers and walleye was 67% by weight and 66% by species frequency. Mean total lengths of gizzard shad, emerald shiner and round goby found in walleye stomachs exceeded those captured in trawls by 47%, on average. Mean total lengths of gizzard shad, emerald shiner and round goby were greater in walleye stomachs than in merganser stomachs. Mean total lengths of emerald shiner and round goby were less in merganser stomachs than in trawls. Our results suggest that although the diets of walleye and mergansers overlapped considerably, mergansers generally consumed smaller fish than walleye. Given the abundance and diversity of prey species available, and the transient nature of mergansers on Lake Erie during migration, we conclude that competition for food between these species is minimal.

  10. Final Supplemental Environmental Impact Statement for Airborne Laser Program at Kirtland Air Force Base (AFB) and White Sands Missile Range/Holloman AFB, NM, and Edwards AFB and Vandenberg AFB, CA

    Science.gov (United States)

    2003-06-01

    californicus- _" -~ T ~ - 1" T - E I T Coho salmon Unarmoured three- spined stickleback I Tidewater goby 1 Eucyclogobius n e w b e p i ,.I...ENDANGERED Black-footed ferret (Mustela nigripes)"" Northern aplomado falcon (Falcofemoralis septentrionalis) Kuenzler hedgehog cachls (Echi...Empidonax traillii ertimus) Kuenzler hedgehog cactus (Echinocer~.~rendleri var. kuenzleri) Todsen’s pennyroyal (Hedeoma fodsenii) Sacramento

  11. Molecular taxonomy study of representatives of the genus Gobius inhabiting coastal waters of Black Sea region

    Directory of Open Access Journals (Sweden)

    Feriha Tserkova

    2016-12-01

    Full Text Available According to their origin the Black Sea gobies can be divided to Ponto-Caspian relicts and Mediterranean immigrants. The increase of species diversity in the Black Sea is a consequence of Mediterranean immigrants. The present study investigated the variability in Cytochrome b sequences isolated from two former Mediterranean immigrant species: Gobius niger and Zosterisessor ophiocephalus. The annotated at NCBI Cyt b sequences of the species were also used to extend the reach of the study. The analyses demonstrated that Black Sea inhabited by four haplotypes of G. niger. Four other haplotypes were found in sequences of Mediterranean black gobies. In the Black Sea haplotype, 6 is predominant and 83.5% of all G. niger representatives belong to it. Three other haplotypes (H_1; H_7 and H_8 were found to form isolated populations. The Tajima D-test indicated that in the Black Sea G. niger in a stage of expansion and significant evolutionary pressure according to data from Maximum Composite Likelihood model of Tamura-Nei, which can explain the accumulation of mutation and appearance of new haplotypes. Unlike G. niger, Z. ophiocephalus populations are shrinking according to Tajima D-test and only one haplotype is still surviving in isolated locations in the Black Sea. These data are in agreement with previous reports of other authors which alarmed that the grass goby is a critically endangered species close to extinction.

  12. Isotopic and geochemical evidence of recharge sources and water quality in the Quaternary aquifer beneath Jinchang city, NW China

    International Nuclear Information System (INIS)

    Ma Jinzhu; Pan Feng; Chen Lihua; Edmunds, W. Mike; Ding Zhenyu; He Jianhua; Zhou Kunpeng; Huang Tianming

    2010-01-01

    Multiple isotopic and hydrogeochemical tracers were utilized to understand the recharge sources and geochemical evolution of groundwater in the Quaternary aquifer beneath Jinchang city and the adjacent Gobi desert area. The groundwater shows markedly depleted stable isotopic composition compared to modern rainfall. The signature of groundwaters from Jinchang and the northern Gobi desert area differ clearly from that of the alluvial fan in the south Yongchang basin and modern rainfall, and has lower or non-detectable 3 H activity, implying that the aquifer is likely maintained by palaeowater. This groundwater in the Gobi desert has a 14 C age older than 12 ka, indicating that the groundwater resources are non-renewable. The build-up of dissolved solids through evaporation is a major control on groundwater composition, and the dominant anion species change systematically from HCO 3 - , SO 4 2- to Cl - , but cations from weathering of albite, calcite, dolomite and gypsum also make a significant contribution. The scientific results have important implications for groundwater management in Jinchang city and as well as in the Shiyang River basin under China's West Development Strategy. It is recommended that the water allocation program of diverting water from the Dongda river to the Minqin basin be reconsidered.

  13. Crustal Structure and Mantle Transition Zone Thickness beneath the Central Mongolia from Teleseismic Receiver Functions

    Science.gov (United States)

    He, J.; Wu, Q.; Gao, M.; Munkhuu, U.; Demberel, S. G.

    2013-12-01

    The Mongolian Plateau (northern Asia) is situated between the Gobi-Altai range and the Siberian craton. In order to understand the crustal and mantle structure environmental characteristics, we use the teleseismic data recorded by 69 broadband stations located in the Central Mongolia(103.5°-111.5°E, 42°-50°N). The teleseismic events are selected from the global earthquakes between Aug. 2011 and Dec. 2013 with magnitude >5.5and the epicentral distance range from 30° to 95° to the center of the network. Lateral variations of the crustal thicknesses H and Vp/Vs ratios are obtained by using receiver function method. The crust thins gradually from northwest to southeast in the studying field. We found that the thinnest crust is ~37.5km in the southeast which is Gobi. The distribution of Vp/Vs ratios are between 1.68 and 1.84, which shows the heterogeneity. There are three high-anomaly areas: the Gobi range which is the Later Paleozoic Orogeny; the Khentei Mountains which is in the Jurassic-Cretaceous Reactive Continental Margin; the northwest area which is granite. Our research not only reveals the powerful evident of the crustal formation and evolution mechanism, but also provides some constraints on the mechanism of uplift of the Mongolian Plateau.This study was supported by the international cooperation project of the Ministry of Science and Technology of China (2011DFB20120).

  14. Age and growth of Crystallogobius linearis (von Düben, 1845 (Teleostei: Gobiidae from the Adriatic Sea

    Directory of Open Access Journals (Sweden)

    M. La Mesa

    2001-12-01

    Full Text Available Age and growth of the crystal goby Crystallogobius linearis (von Düben, 1845 were investigated by means of daily growth increment counts on the sagittal otoliths. Samples of C. linearis, obtained as by-catch of the Aphia minuta fishery, were collected in a coastal area of the central Adriatic Sea between March and September 1996. Otolith age-readings were carried out on 167 specimens, ranged from 14 to 41 mm of total length, and indicated that the population was composed of individuals from two to seven months old. Growth of both males and females appeared practically linear over the whole size range studied, although in females a slight decrease in growth rate of older specimens was observed. Furthermore, the hatch date distribution of C. linearis, obtained by the backcalculation of the ageing data, indicated a long breeding season of at least eight months. The results of this study indicated that, as reported from literature for most nektonic gobies, the crystal goby is also characterised by a short life span, during which a high reproductive effort is displayed throughout a long breeding season.

  15. The tale of two continents

    International Nuclear Information System (INIS)

    Ednie, H.

    2007-01-01

    This article discussed the development of coal resources in Mongolia by Vancouver-based Ivanhoe Mines. SouthGobi Energy Resources is the largest holder of coal lands under exploration in Mongolia, with 2.3 million hectares, comprising 54 exploration licenses. The properties are located in the southern part of Mongolia in the Gobi Desert bordering China. The opportunities for developing coal from Mongolia to be sold to China were summarized. Ovoot Tolgoi is the most advanced of SouthGobi's projects, with 150 million tonnes of coal resources measured and indicated. The initial plan is for the development of a surface mine. A detailed environmental assessment has been completed and approved. The development plans have also been accepted by local communities. Mining equipment will be purchased once the mining license is granted. The operation will start at 1 million tonnes per year, then increase to 5 million tonnes per year in 5 years. The coal is continuous at depth, and plans for an underground operation have already begun. This article also discussed the challenges of conducting business in Mongolia and improving the infrastructure to support the development of mining operations. 3 figs

  16. Amphibious fish jump better on land after acclimation to a terrestrial environment.

    Science.gov (United States)

    Brunt, Emily M; Turko, Andy J; Scott, Graham R; Wright, Patricia A

    2016-10-15

    Air and water differ dramatically in density and viscosity, posing different biomechanical challenges for animal locomotion. We asked how terrestrial acclimation influences locomotion in amphibious fish, specifically testing the hypothesis that terrestrial tail flip performance is improved by plastic changes in the skeletal muscle. Mangrove rivulus Kryptolebias marmoratus, which remain largely inactive out of water, were exposed to water or air for 14 days and a subgroup of air-exposed fish was also recovered in water. Tail flip jumping performance on land improved dramatically in air-acclimated fish, they had lower lactate levels compared with control fish, and these effects were mostly reversible. Muscle plasticity significantly increased oxidative muscle cross-sectional area and fibre size, as well as the number of capillaries per fibre. Our results show that reversible changes to the oxidative skeletal muscle of K. marmoratus out of water enhance terrestrial locomotory performance, even in the absence of exercise training. © 2016. Published by The Company of Biologists Ltd.

  17. The trade-off between heat tolerance and metabolic cost drives the bimodal life strategy at the air-water interface

    KAUST Repository

    Fusi, Marco; Cannicci, Stefano; Daffonchio, Daniele; Mostert, Bruce; Pö rtner, Hans-Otto; Giomi, Folco

    2016-01-01

    The principle of oxygen and capacity limitation of thermal tolerance in ectotherms suggests that the long-term upper limits of an organism's thermal niche are equivalent to the upper limits of the organism's functional capacity for oxygen provision to tissues. Air-breathing ectotherms show wider thermal tolerances, since they can take advantage of the higher availability of oxygen in air than in water. Bimodal species move from aquatic to aerial media and switch between habitats in response to environmental variations such as cyclical or anomalous temperature fluctuations. Here we tested the prediction that bimodal species cope better with thermal stress than truly aquatic species using the crab Pachygrapsus marmoratus as a model species. When in water, oxygen consumption rates of P. marmoratus acutely rise during warming. Beyond a temperature threshold of 23 °C the crab's aerobic metabolism in air remains lower than in water. In parallel, the haemolymph oxygen partial pressure of submerged animals progressive decreases during warming, while it remains low but constant during emersion. Our results demonstrate the ability of a bimodal breathing ectotherm to extend its thermal tolerance during air-breathing, suggesting that there are temperature-related physiological benefits during the evolution of the bimodal life style.

  18. Early Pliocene anuran fossils from Kanapoi, Kenya, and the first fossil record for the African burrowing frog Hemisus (Neobatrachia: Hemisotidae).

    Science.gov (United States)

    Delfino, Massimo

    2017-07-13

    Isolated amphibian bones from the early Pliocene of Kanapoi (West Turkana, Kenya) help to improve the scarce fossil record of the late Neogene and Quaternary amphibians from East Africa. All currently available 579 bones are referable exclusively to the Anura (frogs and toads). More than half of the remains (366) are identified as Hemisus cf. Hemisus marmoratus, an extant species that still inhabits Kenya, but apparently not the northwest of the country and the Turkana area in particular. The rest of the remains are identified simply as Anura indet. because of poor preservation or non congruence with the relatively few African extant taxa whose osteology is known in detail. The Hemisus material represents the first fossil record for Hemisotidae, an endemic African family of peculiar, head-first burrowing frogs, whose sister taxon relationships indicate a divergence from brevicipitids in the Late Cretaceous or early Paleocene. The ecological requirements of extant H. marmoratus suggest that the Kanapoi area surrounding the fluvial and deltaic settings, from where the fossil remains of vertebrates were buried, was likely a grassland or relatively dry, open low tree-shrub savanna. Copyright © 2017 Elsevier Ltd. All rights reserved.

  19. The trade-off between heat tolerance and metabolic cost drives the bimodal life strategy at the air-water interface

    KAUST Repository

    Fusi, Marco

    2016-01-13

    The principle of oxygen and capacity limitation of thermal tolerance in ectotherms suggests that the long-term upper limits of an organism\\'s thermal niche are equivalent to the upper limits of the organism\\'s functional capacity for oxygen provision to tissues. Air-breathing ectotherms show wider thermal tolerances, since they can take advantage of the higher availability of oxygen in air than in water. Bimodal species move from aquatic to aerial media and switch between habitats in response to environmental variations such as cyclical or anomalous temperature fluctuations. Here we tested the prediction that bimodal species cope better with thermal stress than truly aquatic species using the crab Pachygrapsus marmoratus as a model species. When in water, oxygen consumption rates of P. marmoratus acutely rise during warming. Beyond a temperature threshold of 23 °C the crab\\'s aerobic metabolism in air remains lower than in water. In parallel, the haemolymph oxygen partial pressure of submerged animals progressive decreases during warming, while it remains low but constant during emersion. Our results demonstrate the ability of a bimodal breathing ectotherm to extend its thermal tolerance during air-breathing, suggesting that there are temperature-related physiological benefits during the evolution of the bimodal life style.

  20. Bottom trawl assessment of Lake Ontario prey fishes

    Science.gov (United States)

    Weidel, Brian C.; Connerton, Michael J.; Holden, Jeremy

    2018-01-01

    Managing Lake Ontario fisheries in an ecosystem-context requires prey fish community and population data. Since 1978, multiple annual bottom trawl surveys have quantified prey fish dynamics to inform management relative to published Fish Community Objectives. In 2017, two whole-lake surveys collected 341 bottom trawls (spring: 204, fall: 137), at depths from 8-225m, and captured 751,350 fish from 29 species. Alewife were 90% of the total fish catch while Deepwater Sculpin, Round Goby, and Rainbow Smelt comprised the majority of the remaining total catch (3.8, 3.1, and 1.1% respectively). The adult Alewife abundance index for US waters increased in 2017 relative to 2016, however the index for Canadian waters declined. Adult Alewife condition, assessed by the predicted weight of a 165 mm fish (6.5 inches), declined in 2017 from record high values observed in spring 2016. Spring 2017 Alewife condition was slightly less than the 10-year average, but the fall value was well below the 10-year average, likely due to increased Age-1 Alewife abundance. The Age-1 Alewife abundance index was the highest observed in 40 years, and 8-times higher than the previous year. The Age-1 index estimates Alewife reproductive success the preceding year. The warm summer and winter of 2016 likely contributed to the large year class. In contrast the relatively cool 2017 spring and cold winter may result in a lower than average 2017 year class. Abundance indices for Rainbow Smelt, Cisco, and Emerald Shiner either declined or remained at low levels in 2017. Pelagic prey fish diversity continues to be low since a single species, Alewife, dominates the catch. Deepwater Sculpin were the most abundant benthic prey fish in 2017 because Round Goby abundance declined sharply from 2016. Slimy Sculpin density continued to decline and the 2017 biomass index for US waters was the lowest ever observed. Prior to Round Goby proliferation, juvenile Slimy Sculpin comprised ~10% of the Slimy Sculpin catch, but

  1. On the biology and food of small-sized fish from North and Baltic Sea areas. IV. Investigations on an eulittoral mud flat at Sylt Island

    Science.gov (United States)

    Zander, C. Dieter; Hartwig, Eike

    1982-03-01

    The fish fauna of an eulittoral mud flat was investigated at Sylt Island (North Sea) with special regard to its food uptake. During the course of a year the following species were caught: Pomatoschistus microps, Anguilla anguilla (elvers), Zoarces viviparus, and Gasterosteus aculeatus. Considering the potentially available food, the most abundant organisms of the benthos were harpacticoids and nematodes, whereas in the phytal layer gastropods and gammarids were dominant. The benthic biomass was found to be greatest in spring, while phytal organisms were most abundant in late summer. The greatest fish density was stated in September 1974 though only P. microps was present. The fish biomass was highest in spring when the elvers appeared. The main food of P. microps was epibenthos; in the diet of A. anguilla phytal organisms dominated over epibenthos, in G. aculeatus suprabenthic organisms were also present. The most prominent food component by biomass was gammarids in all investigated fish, whereas harpacticoids were only dominant in number. During the course of the year the biomass of ingested food yielded highest values in summer and autumn, but lowest in winter. A very great predatory activity was found in September 1974, which possibly caused a grazing effect on harpacticoids. An estimation of the turnover rate of small-sized fish in this month led to a value of 70 mg dry weight m-2 · d-1.

  2. Food and habitat resource partitioning between three estuarine fish species on the Swedish west coast

    Science.gov (United States)

    Thorman, Staffan

    1983-12-01

    In 1978 the food and habitat resource partitioning of three small and common fish species, viz. Pomatoschistus microps (Krøyer), Gasterosteus aculeatus (L.) and Pungitius pungitius (L.) were studied in river Broälven estuary on the Swedish west coast (58°22'N, 11°29'E). The area was divided into three habitats, based on environmental features. In July, September, and October stomach contents and size distribution of each species present were analysed. In July there was high food and habitat overlap between the species. Interference interactions probably occurred between some size classes of P. microps and the other two species. P. pungitius was exposed to both intra- and interspecific interactions. In September the food and habitat overlaps between G. aculeatus and P. pungitius were high, while both had low food and habitat overlaps in relation to P. microps. Interactions between G. aculeatus and P. pungitius were probably influenced by more severe abiotic conditions in one habitat, which caused lower abundances there, and higher abundances in the other two habitats. In October no interactions were observed. These results indicate that competition for food at least temporarily determines the species distribution in a temperate estuary, and that estuarine fish populations are sometimes food limited.

  3. Impact of climate variability on ichthyoplankton communities: An example of a small temperate estuary

    Science.gov (United States)

    Primo, Ana Lígia; Azeiteiro, Ulisses Miranda; Marques, Sónia Cotrim; Pardal, Miguel Ângelo

    2011-03-01

    Recent variations in the precipitation regime across southern Europe have led to changes in river fluxes and salinity gradients affecting biological communities in most rivers and estuaries. A sampling programme was developed in the Mondego estuary, Portugal, from January 2003 to December 2008 at five distinct sampling stations to evaluate spatial, seasonal and inter-annual distributions of fish larvae. Gobiidae was the most abundant family representing 80% of total catch and Pomatoschistus spp. was the most important taxon. The fish larval community presented a clear seasonality with higher abundances and diversities during spring and summer seasons. Multivariate analysis reinforced differences among seasons but not between years or sampling stations. The taxa Atherina presbyter, Solea solea, Syngnathus abaster, Crystallogobius linearis and Platichthys flesus were more abundant during spring/summer period while Ammodytes tobianus, Callionymus sp., Echiichthys vipera and Liza ramada were more abundant in autumn/winter. Temperature, chlorophyll a and river flow were the main variation drivers observed although extreme drought events (year 2005) seemed not to affect ichthyoplankton community structure. Main changes were related to a spatial displacement of salinity gradient along the estuarine system which produced changes in marine species distribution.

  4. Seasonal, lunar and tidal control of ichthyoplankton dynamics at the interface between a temperate estuary and adjacent coastal waters (western Portugal

    Directory of Open Access Journals (Sweden)

    Ana Lígia Primo

    2011-11-01

    Full Text Available Influence of season, lunar-tide cycle and tide on ichthyoplankton at the interface between Mondego estuary and the adjacent coast and on up-estuary transport was evaluated. Seasonal samples were collected at a fixed station at the mouth of the estuary during diel cycles, at neap and spring tides. Additionally, four sampling stations along the estuary were assessed. Pomatoschistus spp. was the main estuarine taxon, while Sardina pilchardus and Parablennius pilicornis were the most important marine species. Ichthyoplankton entrance and transport along the estuary presented a seasonal pattern with higher densities during summer. Lunar-tide cycle also represented an important influence, structuring communities that reach the estuary and their subsequent distribution. Solea senegalensis and Sardina pilchardus seemed to take advantage of spring tides to enter the estuary. S. pilchardus appear to be using tides to move upstream of the estuary. Ichthyoplankton entrance in the estuary seemed related to species spawning period, while its distribution within the estuary depends on in situ spawning and on the capacity of species to counteract currents and river flow. The present study provides a better understanding of ichthyoplankton dynamics at the interface of two coastal systems, reinforcing knowledge of the lunar-tide cycle influence on ichthyoplankton communities.

  5. Twelve invertebrate and eight fish species new to the marine fauna of Madeira, and a discussion of the zoogeography of the area

    Science.gov (United States)

    Wirtz, Peter

    1998-06-01

    The benthic ctenophore Vallicula multiformis, a large undescribed flatworm species of the genus Pseudoceros, the prosobranch gastropod Tonna maculosa, the opisthobranch gastropods Placida cf. dendritica, Caloria elegans, Aeolidiella sanguinea, Janolus cristatus, the decapod Balssia gasti, the sea urchin Schizaster canaliferus and the tunicates Clavelina lepadiformis, Clavelina dellavallei and Pycnoclavella taureanensis are recorded from Madeira for the first time. This is the first record of a platyctenid ctenophore in the eastern Atlantic. The teleost fishes Pomatoschistus pictus, Vaneaugobius canariensis, Chromogobius sp., Nerophis ophidion, Hippocampus hippocampus, Acanthocybium solandri, Sphyraena viridensis and Sphyraena barracuda are recorded from Madeira for the first time. The presence of the sea-hare Aplysia dactylomela at Madeira is confirmed; the species has increased tremendously in abundance in the last four years. The crocodile fish Grammoplites gruveli can occasionally be found in the mantle cavity of cuttlefish ( Sepia officinalis) sold at the fish market of Funchal, but does not originate from Madeiran waters. An analysis of 100 new records from the coastal fauna of Madeira shows that, while predominantly of lusitanian, mediterranean and mauritanian affinity, Madeira’s shallow water fauna contains a large component of tropical species.

  6. Mudflat nekton assemblages in the Tagus estuary (Portugal: distribution and feeding patterns

    Directory of Open Access Journals (Sweden)

    Susana França

    2008-09-01

    Full Text Available Mudflats are an important component of estuaries, where they may occupy large areas and provide feeding and nursery grounds for many fish and bird species, as in the Tagus estuary. However, knowledge on their role and functioning is still expanding. Spatial and temporal dynamics of nekton assemblages in a mudflat of the Tagus estuary were evaluated to determine their role in the estuarine functioning. Feeding activity and daily rations of the most important nekton species are also analyzed. Two intertidal mudflat areas (upper and lower were sampled, as well as the adjoining subtidal area. Sampling was conducted every two months, during a yearly cycle. A 24 h sampling cycle was conducted to investigate daily feeding patterns and determine daily rations. Crangon crangon, Carcinus maenas, Palaemon longirostris, Palaemon serratus and Pomatoschistus microps dominated the nekton community. A marked seasonal pattern was noticed with the highest densities recorded in spring and summer, corresponding to recruitment episodes of these species. Highest biomass values were recorded in the subtidal zone, while the highest densities were recorded in the intertidal zone. The mudflats seem to play an important role in the dynamics of the Tagus estuary, acting as a feeding and nursery areas for several nektonic species.

  7. Composição em tamanho dos peixes (Actinopterygii, Teleostei de ribeirões da bacia do rio Tibagi, Paraná, Brasil

    Directory of Open Access Journals (Sweden)

    Shibatta Oscar A.

    2003-01-01

    Full Text Available The standard length of 7610 specimens of 43 species from eight streams of rio Tibagi basin was obtained in order to analyze the means of fish sizes. The higher mean size was observed in Gymnotus carapo Linnaeus, 1758 (165,5 mm and the smaller, in Phalloceros caudimaculatus (Hensel, 1868 (16,25 mm. Some fish like Acestrorhynchus lacustris (Reinhardt, 1874, Leporinus obtusidens (Valenciennes, 1836, Gymnotus carapo Linneus, 1758 and Synbranchus marmoratus Bloch, 1795 can reach big or medium size when adults but were collected only young, evidencing they use some streams in beginning of life. The mean size of total species was 49,81mm, what shows the small size composition of fishes in the streams. The Kolmogov-Smirnov test comparing the mean size of all streams showed significant similar size both in upstream and downstream regions, independent to the different environmental conditions.

  8. Diversidad y microestructura de quitones (Mollusca: Polyplacophora del Caribe de Costa Rica

    Directory of Open Access Journals (Sweden)

    Cedar I García-Ríos

    2011-03-01

    Full Text Available Los poliplacóforos asociados a los arrecifes de coral en la costa caribeña de Costa Rica han sido poco estudiados. El examen del cascajo de coral acumulado en el sublitoral somero, en cuatro estaciones de colección, localizadas en la Provincia de Limón reveló una diversidad de quitones mayor a la documentada. Anteriormente se habían registrado ocho especies para el Caribe costaricense: Ischnochiton erythronotus (C.B. Adams, 1845; Ischnoplax pectinata (Sowerby 1840; Stenoplax boogii (Haddon, 1886; S. purpurascens (C.B. Adams, 1845; Acanthopleura granulata (Gmelin, 1791; Chiton marmoratus Gmelin, 1791; C. tuberculatus Linnaeus, 1758; Acanthochitona rhodea (Pilsbry, 1893. Otras cinco se registran aquí por primera vez: Callistochiton portobelensis Ferreira 1976; Ischnochiton kaasi Ferreira 1987; I. pseudovirgatus Kaas 1972; Acanthochitona balesae Abbott 1954; Cryptoconchus floridanus (Dall 1889.

  9. Environmental disturbance and conservation of marine and shoreline birds on the west coast of Vancouver Island

    International Nuclear Information System (INIS)

    Morgan, K.H.; Butler, R.W.; Vermeer, R.W.

    1992-01-01

    Loss of habitat and oiling of birds represent two major threats to marine and shoreline bird populations on Vancouver Island's west coast, since their effects are widespread and cumulative. Offshore tanker traffic and local inshore shipments of petroleum products expose the coast to high risks of oiling. Large numbers of birds are most at risk when concentrated in relatively small areas, such as highly productive feeding areas, at communal roosting sites, and around nesting colonies. Logging of mature and old-growth forests has led to destruction of the nesting habitat of marbled murrelets (Brachyramphus marmoratus), while industrial development of estuaries, mudflats, and spawning grounds of Pacific herring (Clupea harengus pallasi) has diminished feeding habitats for other marine and shoreline birds. Fisheries operations, human disturbance of colonies, and introduced predators, notably the raccoon (Procyon lotor) and mink (Mustela vison), have impacted upon local populations. Management actions and research needs to mitigate these threats are addressed. 40 refs

  10. Diet of Lontra longicaudis (Olfers, 1818 (Carnivora: Mustelidae in three limnic systems in Southern Rio Grande do Sul State, Brazil

    Directory of Open Access Journals (Sweden)

    Fernando Marques Quintela

    2012-12-01

    Full Text Available The aim of the present work was to study the diet of Lontra longicaudis in three limnic systems (anthropogenic shallow lakes, pluvial channel and coastal stream in Rio Grande do Sul State coastal plain, southern Brazil. Fishes were the most consumed item in all the three systems, being Mugilidae the most representative family in the pluvial channel and coastal stream and Cichlidae in the shallow lakes. Other identified items were mollusks, insects, crustaceans, amphibians, reptiles, birds and mammals and vegetal fragments. The high frequency of birds in the shallow lakes was remarkable, considering the lower frequencies of this item in previous investigations on the species diet. There was a high frequency of swamp eels (Synbranchidae, Synbranchus marmoratus in the pluvial channel and shallow lakes, which were usually absent or found in low frequencies in previous studies.

  11. Musculoskeletal determinants of pelvic sucker function in Hawaiian stream gobiid fishes: interspecific comparisons and allometric scaling.

    Science.gov (United States)

    Maie, Takashi; Schoenfuss, Heiko L; Blob, Richard W

    2013-07-01

    Gobiid fishes possess a distinctive ventral sucker, formed from fusion of the pelvic fins. This sucker is used to adhere to a wide range of substrates including, in some species, the vertical cliffs of waterfalls that are climbed during upstream migrations. Previous studies of waterfall-climbing goby species have found that pressure differentials and adhesive forces generated by the sucker increase with positive allometry as fish grow in size, despite isometry or negative allometry of sucker area. To produce such scaling patterns for pressure differential and adhesive force, waterfall-climbing gobies might exhibit allometry for other muscular or skeletal components of the pelvic sucker that contribute to its adhesive function. In this study, we used anatomical dissections and modeling to evaluate the potential for allometric growth in the cross-sectional area, effective mechanical advantage (EMA), and force generating capacity of major protractor and retractor muscles of the pelvic sucker (m. protractor ischii and m. retractor ischii) that help to expand the sealed volume of the sucker to produce pressure differentials and adhesive force. We compared patterns for three Hawaiian gobiid species: a nonclimber (Stenogobius hawaiiensis), an ontogenetically limited climber (Awaous guamensis), and a proficient climber (Sicyopterus stimpsoni). Scaling patterns were relatively similar for all three species, typically exhibiting isometric or negatively allometric scaling for the muscles and lever systems examined. Although these scaling patterns do not help to explain the positive allometry of pressure differentials and adhesive force as climbing gobies grow, the best climber among the species we compared, S. stimpsoni, does exhibit the highest calculated estimates of EMA, muscular input force, and output force for pelvic sucker retraction at any body size, potentially facilitating its adhesive ability. Copyright © 2013 Wiley Periodicals, Inc.

  12. The latest geodynamics in Asia: Synthesis of data on volcanic evolution, lithosphere motion, and mantle velocities in the Baikal-Mongolian region

    Directory of Open Access Journals (Sweden)

    Sergei Rasskazov

    2017-07-01

    Full Text Available From a synthesis of data on volcanic evolution, movement of the lithosphere, and mantle velocities in the Baikal-Mongolian region, we propose a comprehensive model for deep dynamics of Asia that assumes an important role of the Gobi, Baikal, and North Transbaikal transition-layer melting anomalies. This layer was distorted by lower-mantle fluxes at the beginning of the latest geodynamic stage (i.e. in the early late Cretaceous due to avalanches of slab material that were stagnated beneath the closed fragments of the Solonker, Ural-Mongolian paleoceans and Mongol-Okhotsk Gulf of Paleo-Pacific. At the latest geodynamic stage, Asia was involved in east–southeast movement, and the Pacific plate moved in the opposite direction with subduction under Asia. The weakened upper mantle region of the Gobi melting anomaly provided a counterflow connected with rollback in the Japan Sea area. These dynamics resulted in the formation of the Honshu-Korea flexure of the Pacific slab. A similar weakened upper mantle region of the North Transbaikal melting anomaly was associated with the formation of the Hokkaido-Amur flexure of the Pacific slab, formed due to progressive pull-down of the slab material into the transition layer in the direction of the Pacific plate and Asia convergence. The early–middle Miocene structural reorganization of the mantle processes in Asia resulted in the development of upper mantle low-velocity domains associated with the development of rifts and orogens. We propose that extension at the Baikal Rift was caused by deviator flowing mantle material, initiated under the moving lithosphere in the Baikal melting anomaly. Contraction at the Hangay orogen was created by facilitation of the tectonic stress transfer from the Indo-Asian interaction zone due to the low-viscosity mantle in the Gobi melting anomaly.

  13. Evolution of microhabitat association and morphology in a diverse group of cryptobenthic coral reef fishes (Teleostei: Gobiidae: Eviota)

    KAUST Repository

    Tornabene, Luke; Ahmadia, Gabby N.; Berumen, Michael L.; Smith, David J.; Jompa, Jamaluddì n; Pezold, Frank L.

    2013-01-01

    Gobies (Teleostei: Gobiidae) are an extremely diverse and widely distributed group and are the second most species rich family of vertebrates. Ecological drivers are key to the evolutionary success of the Gobiidae. However, ecological and phylogenetic data are lacking for many diverse genera of gobies. Our study investigated the evolution of microhabitat association across the phylogeny of 18 species of dwarfgobies (genus Eviota), an abundant and diverse group of coral reef fishes. In addition, we also explore the evolution of pectoral fin-ray branching and sensory head pores to determine the relationship between morphological evolution and microhabitat shifts. Our results demonstrate that Eviota species switched multiple times from a facultative hard-coral association to inhabiting rubble or mixed sand/rubble habitat. We found no obvious relationship between microhabitat shifts and changes in pectoral fin-ray branching or reduction in sensory pores, with the latter character being highly homoplasious throughout the genus. The relative flexibility in coral-association in Eviota combined with the ability to move into non-coral habitats suggests a genetic capacity for ecological release in contrast to the strict obligate coral-dwelling relationship commonly observed in closely related coral gobies, thus promoting co-existence through fine scale niche partitioning. The variation in microhabitat association may facilitate opportunistic ecological speciation, and species persistence in the face of environmental change. This increased speciation opportunity, in concert with a high resilience to extinction, may explain the exceptionally high diversity seen in Eviota compared to related genera in the family. © 2012 Elsevier Inc.

  14. Performance and scaling of a novel locomotor structure: adhesive capacity of climbing gobiid fishes.

    Science.gov (United States)

    Maie, Takashi; Schoenfuss, Heiko L; Blob, Richard W

    2012-11-15

    Many species of gobiid fishes adhere to surfaces using a sucker formed from fusion of the pelvic fins. Juveniles of many amphidromous species use this pelvic sucker to scale waterfalls during migrations to upstream habitats after an oceanic larval phase. However, adults may still use suckers to re-scale waterfalls if displaced. If attachment force is proportional to sucker area and if growth of the sucker is isometric, then increases in the forces that climbing fish must resist might outpace adhesive capacity, causing climbing performance to decline through ontogeny. To test for such trends, we measured pressure differentials and adhesive suction forces generated by the pelvic sucker across wide size ranges in six goby species, including climbing and non-climbing taxa. Suction was achieved via two distinct growth strategies: (1) small suckers with isometric (or negatively allometric) scaling among climbing gobies and (2) large suckers with positively allometric growth in non-climbing gobies. Species using the first strategy show a high baseline of adhesive capacity that may aid climbing performance throughout ontogeny, with pressure differentials and suction forces much greater than expected if adhesion were a passive function of sucker area. In contrast, large suckers possessed by non-climbing species may help compensate for reduced pressure differentials, thereby producing suction sufficient to support body weight. Climbing Sicyopterus species also use oral suckers during climbing waterfalls, and these exhibited scaling patterns similar to those for pelvic suckers. However, oral suction force was considerably lower than that for pelvic suckers, reducing the ability for these fish to attach to substrates by the oral sucker alone.

  15. Biology and ecomorphology of stream fishes from the rio Mogi-Guaçu basin, Southeastern Brazil

    Directory of Open Access Journals (Sweden)

    Katiane M. Ferreira

    Full Text Available The córrego Paulicéia is a direct tributary of the rio Mogi-Guaçu, located in Santa Rita do Passa Quatro, State of São Paulo, Southeastern Brazil. This stream runs inside a savannah-like (cerrado environment and it associated vegetation. Biological and ecomorphological aspects of its fish community were studied in three stretches of the stream, denominated herein as the upper, middle and lower courses. The fish fauna recorded in this study consisted of 15 species, belonging to five orders and nine families, based in a total of 715 collected individuals representing 1,450 kg of biomass. The most important abiotic factors related to the occurrence and distribution of the fish fauna were the substrate, current speed, and presence or absence of riparian vegetation. The analysis of 336 stomach contents of 13 species demonstrated that 65% of food items are autochthonous, 32% allochthonous, and 3% are of unknown origin. Four alimentary guilds could be identified, based on the predominant food items: omnivores with tendency to insectivory - Astyanax paranae, A. fasciatus and Piabina argentea; larvivores - Corydoras difluviatilis, Cetopsorhamdia iheringi, Phenacorhamdia tenebrosa, Characidium gomesi, Eigenmannia virescens, and Rhamdia quelen; periphyton feeders - Hisonotus sp., Hypostomus ancistroides and Synbranchus marmoratus; and piscivore - Hoplias malabaricus. Reproductions data are presented for Astyanax altiparanae and Hisontus sp. Three ecomorphological groups could be established, based on swimming, feeding, and microhabitat strategies: nektonic (A. fasciatus, A. paranae, Bryconamericus stramineus, P. argentea, H. malabaricus and Phallotorynus jucundus, benthic (C. gomesi, P. tenebrosa, C. iheringi, R. quelen, C. difluviatilis, H. ancistroides and Hisonotus sp., and necktobenthic (E. virescens and S. marmoratus.

  16. Diversidad y microestructura de quitones (Mollusca: Polyplacophora del Caribe de Costa Rica

    Directory of Open Access Journals (Sweden)

    Cedar I García-Ríos

    2011-03-01

    Full Text Available Los poliplacóforos asociados a los arrecifes de coral en la costa caribeña de Costa Rica han sido poco estudiados. El examen del cascajo de coral acumulado en el sublitoral somero, en cuatro estaciones de colección, localizadas en la Provincia de Limón reveló una diversidad de quitones mayor a la documentada. Anteriormente se habían registrado ocho especies para el Caribe costaricense: Ischnochiton erythronotus (C.B. Adams, 1845; Ischnoplax pectinata (Sowerby 1840; Stenoplax boogii (Haddon, 1886; S. purpurascens (C.B. Adams, 1845; Acanthopleura granulata (Gmelin, 1791; Chiton marmoratus Gmelin, 1791; C. tuberculatus Linnaeus, 1758; Acanthochitona rhodea (Pilsbry, 1893. Otras cinco se registran aquí por primera vez: Callistochiton portobelensis Ferreira 1976; Ischnochiton kaasi Ferreira 1987; I. pseudovirgatus Kaas 1972; Acanthochitona balesae Abbott 1954; Cryptoconchus floridanus (Dall 1889.Diversity and microstructure of quitons (Mollusca: Polyplacophora from the Caribbean of Costa Rica. The polyplacophorans of the coral reef on the Caribbean coast of Costa Rica have been insufficiently studied. The examination of coral rubble accumulated in the shallow sublitoral waters on four collection stations in Provincia Limón revealed a higher diversity of chitons than was documented. From the country eight species were previously known: Ischnochiton erythronotus (C.B. Adams 1845; Ischnoplax pectinata (Sowerby 1840; Stenoplax boogii (Haddon 1886; S. purpurascens (C.B. Adams 1845; Acanthopleura granulate (Gmelin 1791; Chiton marmoratus Gmelin 1791; C. tuberculatus Linnaeus 1758 and Acanthochitona rhodea (Pilsbry 1893. This study added five more species that are reported here for the first time: Callistochiton portobelensis Ferreira 1976; Ischnochiton kaasi Ferreira 1987; I. pseudovirgatus Kaas 1972; Acanthochitona balesae Abbott 1954 and Cryptoconchus floridanus (Dall 1889. Rev. Biol. Trop. 59 (1: 129-136. Epub 2011 March 01.

  17. Long-term monitoring of tropical alpine habitat change, Andean anurans, and chytrid fungus in the Cordillera Vilcanota, Peru: Results from a decade of study.

    Science.gov (United States)

    Seimon, Tracie A; Seimon, Anton; Yager, Karina; Reider, Kelsey; Delgado, Amanda; Sowell, Preston; Tupayachi, Alfredo; Konecky, Bronwen; McAloose, Denise; Halloy, Stephan

    2017-03-01

    The Cordillera Vilcanota in southern Peru is the second largest glacierized range in the tropics and home to one of the largest high-alpine lakes, Sibinacocha (4,860 m). Here, Telmatobius marmoratus (marbled water frog), Rhinella spinulosa (Andean toad), and Pleurodema marmoratum (marbled four-eyed frog) have expanded their range vertically within the past century to inhabit newly formed ponds created by ongoing deglaciation. These anuran populations, geographically among the highest (5,200-5,400 m) recorded globally, are being impacted by the chytrid fungus Batrachochytrium dendrobatidis ( Bd ), and the disease it causes, chytridiomycosis. In this study, we report results from over a decade of monitoring these three anuran species, their habitat, and Bd infection status. Our observations reveal dynamic changes in habitat including ongoing rapid deglaciation (18.4 m/year widening of a corridor between retreating glaciers from 2005 to 2015), new pond formation, changes in vegetation in amphibian habitat, and widespread occurrence of Bd in amphibians in seven sites. Three of these sites have tested positive for Bd over a 9- to 12-year period. In addition, we observed a widespread reduction in T. marmoratus encounters in the Vilcanota in 2008, 2009, and 2012, while encounters increased in 2013 and 2015. Despite the rapid and dynamic changes in habitat under a warming climate, continued presence of Bd in the environment for over a decade, and a reduction in one of three anuran species, we document that these anurans continue to breed and survive in this high Andean environment. High variability in anuran encounters across sites and plasticity in these populations across habitats, sites, and years are all factors that could favor repopulation postdecline. Preserving the connectivity of wetlands in the Cordillera Vilcanota is therefore essential in ensuring that anurans continue to breed and adapt as climate change continues to reshape the environment.

  18. A mid-Pleistocene rainforest corridor enabled synchronous invasions of the Atlantic Forest by Amazonian anole lizards.

    Science.gov (United States)

    Prates, Ivan; Rivera, Danielle; Rodrigues, Miguel T; Carnaval, Ana C

    2016-10-01

    Shifts in the geographic distribution of habitats over time can promote dispersal and vicariance, thereby influencing large-scale biogeographic patterns and ecological processes. An example is that of transient corridors of suitable habitat across disjunct but ecologically similar regions, which have been associated with climate change over time. Such connections likely played a role in the assembly of tropical communities, especially within the highly diverse Amazonian and Atlantic rainforests of South America. Although these forests are presently separated by open and dry ecosystems, paleoclimatic and phylogenetic evidence suggest that they have been transiently connected in the past. However, little is known about the timing, magnitude and the distribution of former forest connections. We employ sequence data at multiple loci from three codistributed arboreal lizards (Anolis punctatus, Anolis ortonii and Polychrus marmoratus) to infer the phylogenetic relationships among Amazonian and Atlantic Forest populations and to test alternative historical demographic scenarios of colonization and vicariance using coalescent simulations and approximate Bayesian computation (ABC). Data from the better-sampled Anolis species support colonization of the Atlantic Forest from eastern Amazonia. Hierarchical ABC indicates that the three species colonized the Atlantic Forest synchronously during the mid-Pleistocene. We find support of population bottlenecks associated with founder events in the two Anolis, but not in P. marmoratus, consistently with their distinct ecological tolerances. Our findings support that climatic fluctuations provided key opportunities for dispersal and forest colonization in eastern South America through the cessation of environmental barriers. Evidence of species-specific histories strengthens assertions that biological attributes play a role in responses to shared environmental change. © 2016 John Wiley & Sons Ltd.

  19. Benthic prey fish assessment, Lake Ontario 2013

    Science.gov (United States)

    Weidel, Brian C.; Walsh, Maureen; Connerton, Michael J.

    2014-01-01

    The 2013 benthic fish assessment was delayed and shortened as a result of the U.S. Government shutdown, however the assessment collected 51 of the 62 planned bottom trawls. Over the past 34 years, Slimy Sculpin abundance in Lake Ontario has fluctuated, but ultimately decreased by two orders of magnitude, with a substantial decline occurring in the past 10 years. The 2013 Slimy Sculpin mean bottom trawl catch density (0.001 ind.·m-2, s.d.= 0.0017, n = 52) and mean biomass density (0.015 g·m-2 , s.d.= 0.038, n = 52) were the lowest recorded in the 27 years of sampling using the original bottom trawl design. From 2011-2013, the Slimy Sculpin density and biomass density has decreased by approximately 50% each year. Spring bottom trawl catches illustrate Slimy Sculpin and Round Goby Neogobius melanostoma winter habitat overlaps for as much as 7 months out of a year, providing opportunities for competition and predation. Invasive species, salmonid piscivory, and declines in native benthic invertebrates are likely all important drivers of Slimy Sculpin population dynamics in Lake Ontario. Deepwater Sculpin Myoxocephalus thompsonii, considered rare or absent from Lake Ontario for 30 years, have generally increased over the past eight years. For the first time since they were caught in this assessment, Deepwater Sculpin density and biomass density estimates declined from the previous year. The 2013 abundance and density estimates for trawls covering the standard depths from 60m to 150m was 0.0001 fish per square meter and 0.0028 grams per square meter. In 2013, very few small (recruitment. Nonnative Round Gobies were first detected in the USGS/NYSDEC Lake Ontario spring Alewife assessment in 2002. Since that assessment, observations indicate their population has expanded and they are now found along the entire south shore of Lake Ontario, with the highest densities in U.S. waters just east of the Niagara River confluence. In the 2013 spring-based assessment, both the

  20. Impacto del buen gobierno corporativo en la generación de valor financiero de empresas representativas del sector cementero de Perú y Colombia

    OpenAIRE

    Borda Guerra, Alex; Gago Martínez, Angélica; Masuda Cáceres, Vicente; Viviano Bustinza, Magin

    2017-01-01

    x, 184 h. : il. ; 30cm. La presente tesis realiza el análisis de las empresas representativas del sector cementero de Perú y Colombia con prácticas de buen gobierno corporativo y su implicancia en la generación de valor financiero a partir de la revisión de los reportes o códigos de gobierno corporativo y estados financieros auditados publicados en medios oficiales por las empresas que conforman el estudio. Una vez que se recopiló la información de las prácticas de buen gobi...

  1. Nematode eel parasite found inside acanthocephalan cysts--a "Trojan horse" strategy?

    Science.gov (United States)

    Emde, Sebastian; Rueckert, Sonja; Kochmann, Judith; Knopf, Klaus; Sures, Bernd; Klimpel, Sven

    2014-11-18

    The invasive eel parasite Anguillicoloides crassus (syn. Anguillicola crassus) is considered one of the major causes for the decline of the European eel (Anguilla anguilla) panmictic population. It impairs the swim bladder function and reduces swimming performance of its host. The life cycle of this parasite involves different intermediate and paratenic hosts. Despite an efficient immune system of the paratenic fish hosts acting against infections with A. crassus, levels of parasitized eels remain high in European river systems. Recently, the round goby Neogobius melanostomus (Gobiidae) has become dominant in many rivers in Europe and is still spreading at a rapid pace. This highly invasive species might potentially act as an important, so far neglected paratenic fish host for A. crassus. Based on own observations and earlier single sightings of A. crassus in N. melanostomus, 60 fresh individuals of N. melanostomus were caught in the Rhine River and examined to assess the infection levels with metazoan parasites, especially A. crassus. Glycerin preparations were used for parasite identification. The parasite most frequently found in N. melanostomus was the acanthocephalan Pomphorhynchus sp. (subadult stage) which occurred mainly encysted in the mesenteries and liver. Every third gobiid (P = 31.7%) was infected by A. crassus larvae (L3) which exclusively occurred inside the acanthocephalan cysts. No intact or degenerated larvae of A. crassus were detected elsewhere in the goby, neither in the body cavity and mesenteries nor in other organs. Affected cysts contained the acanthocephalan larvae and 1-12 (mI =3) living A. crassus larvae. Additionally, encysted larvae of the nematode Raphidascaris acus were detected in the gobies, but only in the body cavity and not inside the acanthocephalan cysts. Based on our observations, we suggest that A. crassus might actively bypass the immune response of N. melanostomus by invading the cysts of acanthocephalan parasites of the

  2. Preconstruction Biogeochemical Analysis of Mercury in Wetlands Bordering the Hamilton Army Airfield (HAAF) Wetlands Restoration Site. Part 3

    Science.gov (United States)

    2009-12-01

    but not included in the analyzed samples, were zooplankton, bacteria, and larvae for the Asian clam and mysids for the shrimp (Table 5-4). The...Asian clam, shrimp , goby) may contribute the most, while the central role of detritus-associated MeHg has to be further explored. The Questions and...Asian clam) Bay 1 -20.9 (-) 11.6 (-) 13.3 (-) Shrimp sp. Bay 6 -19.6 (0.4) 15.4 (1.6) 14.7 (1.4) Carcinus maenas (European green crab) Bay

  3. "Poder Ciudadano" e tutela dell'Etica Pubblica nella Costituzione Venezuelana del 1999

    OpenAIRE

    Claudia Esposito

    2011-01-01

    El objetivo de esta investigación es analizar los temas desarrolados sobre el papel de la Ética Pública en una democracia moderna. En primer lugar se analiza la introducción del Poder Ciudadano y en particular del Defensor del Pueblo en la Constitución Venezolana de 1999, como medio no jurisdicional de tutela de los derechos humanos. El método adoptado es de tipo documental. En las conclusiones se resalta la importancia de la Ética publica como medio de participación de los ciudadanos al gobi...

  4. Deep Learning Methods for Quantifying Invasive Benthic Species in the Great Lakes

    Science.gov (United States)

    Billings, G.; Skinner, K.; Johnson-Roberson, M.

    2017-12-01

    In recent decades, invasive species such as the round goby and dreissenid mussels have greatly impacted the Great Lakes ecosystem. It is critical to monitor these species, model their distribution, and quantify the impacts on the native fisheries and surrounding ecosystem in order to develop an effective management response. However, data collection in underwater environments is challenging and expensive. Furthermore, the round goby is typically found in rocky habitats, which are inaccessible to standard survey techniques such as bottom trawling. In this work we propose a robotic system for visual data collection to automatically detect and quantify invasive round gobies and mussels in the Great Lakes. Robotic platforms equipped with cameras can perform efficient, cost-effective, low-bias benthic surveys. This data collection can be further optimized through automatic detection and annotation of the target species. Deep learning methods have shown success in image recognition tasks. However, these methods often rely on a labelled training dataset, with up to millions of labelled images. Hand labeling large numbers of images is expensive and often impracticable. Furthermore, data collected in the field may be sparse when only considering images that contain the objects of interest. It is easier to collect dense, clean data in controlled lab settings, but this data is not a realistic representation of real field environments. In this work, we propose a deep learning approach to generate a large set of labelled training data realistic of underwater environments in the field. To generate these images, first we draw random sample images of individual fish and mussels from a library of images captured in a controlled lab environment. Next, these randomly drawn samples will be automatically merged into natural background images. Finally, we will use a generative adversarial network (GAN) that incorporates constraints of the physical model of underwater light propagation

  5. El filibusterismo en los mensajes al Congreso de los presidentes de los Estados Unidos y la Ley de Neutralidad 1848-1860

    OpenAIRE

    Fallas Santana, Carmen María

    2011-01-01

    En este artículo se analiza el abordaje del filibusterismo en los mensajes al Congreso de los presidentes de Estados Unidos en el periodo comprendido entre el fin de la guerra con México y el inicio de la Guerra Civil. Argumenta que todas las administraciones declararon su compromiso de suprimir el filibusterismo porque era perjudicial para los intereses comerciales, políticos y económicos, la seguridad nacional y las relaciones exteriores. Señala que el rechazo de las peticiones de los gobie...

  6. Redescription of Coryphopterus tortugae (Jordan) and a new allied species Coryphopterus bol (Perciformes: Gobiidae: Gobiinae) from the tropical western Atlantic Ocean

    OpenAIRE

    Victor, Benjamin C.

    2008-01-01

    A re-examination of the holotype and mtDNA barcoding confirms Garzon-Ferreira and Acero’s separation of Coryphopterus tortugae from C. glaucofraenum. However, specimens matching the markings of their Santa Marta variant of C. tortugae comprise a distinct clade about 10% sequence divergent from true C. tortugae and C. glauco-fraenum. The variant is described here as a new species, the sand-canyon goby Coryphopterus bol, from specimens collected in Puerto Rico, the US Virgin Islands, and the At...

  7. Evaluating dispersal potential of an invasive fish by the use of aerobic scope and osmoregulation capacity

    DEFF Research Database (Denmark)

    Behrens, Jane W.; Deurs, Mikael van; Christensen, Emil Aputsiaq Flindt

    2017-01-01

    factors such as presence of predators, competitors, and parasites. Early prediction of dispersal potential and future 'area of impact' is challenging, but also a great asset in taking appropriate management actions. Aerobic scope (AS) in fish has been linked to various fitness-related parameters, and may...... waters is unknown to date. We show that AS in round goby is reduced by 30% and blood plasma osmolality increased (indicating reduced capacity for osmoregulation) at salinities approaching oceanic conditions, following slow ramping (5 PSU per week) and subsequent long-term acclimation to salinities...

  8. The diet of whiting Merlangius merlangus in the western Baltic Sea

    DEFF Research Database (Denmark)

    Ross, Stine Dalmann; Gislason, Henrik; Andersen, Niels Gerner

    2016-01-01

    The diet of whiting Merlangius merlangus in the western Baltic Sea was investigated and compared to the diet in the southern North Sea. Clupeids were important prey in both areas, but especially in the western Baltic Sea where they constituted up to 90% of the diet of larger individuals. Gobies......, brown shrimps and polychaetes were the main prey of juveniles in the western Baltic Sea, while a wider range of species were consumed in the North Sea. The shift to piscivory occurred at smaller sizes in the western Baltic Sea and the fish prey consumed was proportionately larger than in the southern...

  9. The basic features of clay rock in Tamusu area

    International Nuclear Information System (INIS)

    Liu Xiaodong; Liu Pinghui

    2012-01-01

    This paper introduces the Tamusu area location, natural and social economic situation, the regional geological background, as well as the upper Gobi formation of clay rocks, and from the geological conditions, economic conditions, social conditions and other aspects of the Tamusu claystone conducted a preliminary evaluation. The results showed that this area can be used as one of the favorable preselected areas for high-level radioactive waste geological disposal repository, basically meets the siting criteria for geological conditions, environmental protection, land use, social influence and waste transport etc. (authors)

  10. A theropod dinosaur embryo and the affinities of the flaming cliffs dinosaur eggs.

    Science.gov (United States)

    Norell, M A; Clark, J M; Demberelyin, D; Rhinchen, B; Chiappe, L M; Davidson, A R; McKenna, M C; Altangerel, P; Novacek, M J

    1994-11-04

    An embryonic skeleton of a nonavian theropod dinosaur was found preserved in an egg from Upper Cretaceous rocks in the Gobi Desert of Mongolia. Cranial features identify the embryo as a member of Oviraptoridae. Two embryo-sized skulls of dromaeosaurids, similar to that of Velociraptor, were also recovered in the nest. The eggshell microstructure is similar to that of ratite birds and is of a type common in the Djadokhta Formation at the Flaming Cliffs (Bayn Dzak). Discovery of a nest of such eggs at the Flaming Cliffs in 1923, beneath the Oviraptor philoceratops holotype, suggests that this dinosaur may have been a brooding adult.

  11. Asthenospheric counterflows beneath the moving lithosphere of Central and East Asia in the past 90 Ma: volcanic and tomographic evidence

    Science.gov (United States)

    Rasskazov, Sergei; Chuvashova, Irina; Kozhevnikov, Vladimir

    2015-04-01

    Asthenospheric counterflows, accompanied motions of the lithosphere in Central and East Asia, are defined on basis of spatial-temporal activity of mantle sources [Rasskazov et al., 2012; Rasskazov, Chuvashova, 2013; Chuvashova, Rasskazov, 2014] and the tomographic model of the Rayleigh wave group velocities [Kozhevnikov et al., 2014]. The opposite fluxes are defined relative to centers of convective instability (low-velocity anomalies), expressed by thinning of the mantle transition layer under Southwestern Gobi (44 °N, 95 °E) and Northern Baikal (52 °N, 108 °E). Cretaceous-Paleogene volcanic fields in Southern Gobi are shifted eastwards relative to the former anomaly over 600 km with the opposite sub-lithospheric flux at depths of 150-300 km. Likewise, the Late Tertiary Vitim volcanic field is shifted relative to the latter anomaly over 100-200 km. We suggest that the Gobi and Baikal asthenospheric counterflows contributed to the rollback mechanism of downgoing slab material from the Pacific under the eastern margin of Asia in the Cretaceous-Paleogene and Early-Middle Miocene. The east-west Gobi reverse flux, caused by differential block motions in front of the Indo-Asian convergence, resulted in the oblique Honshu-Korean flexure of the Pacific slab that propagated beneath the continental margin, while the Japan Sea was quickly opening at about 15 Ma. The Baikal N60°W reverse flux, originated due to oncoming traffic between Eurasia and the Pacific plate, entailed the formation of the Baikal Rift Zone and direct Hokkaido Amur slab flexure [Rasskazov et al., 2004]. The study is supported by the Russian Foundation for Basic Research (Grant 14-05-31328). References Chuvashova I.S., Rasskazov S.V. Magmatic sources in the mantle of the evolving Earth. Irkutsk: Publishing House of the Irkutsk State University, 2014. 310 p. (in Russian) Kozhevnikov V.M., Seredkina A.I., Solovei O.A. 3D mantle structure of Central Asia from Rayleigh wave group velocity dispersion

  12. Trophic specialization drives morphological evolution in sea snakes.

    Science.gov (United States)

    Sherratt, Emma; Rasmussen, Arne R; Sanders, Kate L

    2018-03-01

    Viviparous sea snakes are the most rapidly speciating reptiles known, yet the ecological factors underlying this radiation are poorly understood. Here, we reconstructed dated trees for 75% of sea snake species and quantified body shape (forebody relative to hindbody girth), maximum body length and trophic diversity to examine how dietary specialization has influenced morphological diversification in this rapid radiation. We show that sea snake body shape and size are strongly correlated with the proportion of burrowing prey in the diet. Specialist predators of burrowing eels have convergently evolved a 'microcephalic' morphotype with dramatically reduced forebody relative to hindbody girth and intermediate body length. By comparison, snakes that predominantly feed on burrowing gobies are generally short-bodied and small-headed, but there is no evidence of convergent evolution. The eel specialists also exhibit faster rates of size and shape evolution compared to all other sea snakes, including those that feed on gobies. Our results suggest that trophic specialization to particular burrowing prey (eels) has invoked strong selective pressures that manifest as predictable and rapid morphological changes. Further studies are needed to examine the genetic and developmental mechanisms underlying these dramatic morphological changes and assess their role in sea snake speciation.

  13. Community shelter use in response to two benthic decapod predators in the Long Island Sound.

    Science.gov (United States)

    Hudson, David M; Reagan, Dugan; Crivello, Joseph F

    2016-01-01

    To investigate community shelter effects of two invasive decapod species, Hemigrapsus sanguineus and Carcinus maenas, in the Long Island Sound (LIS), we deployed artificial shelters in the intertidal and immediate subtidal zones. These consisted of five groups during the summer: a control, a resident H. sanguineus male or female group, and a resident C. maenas male or female group. We quantified utilization of the shelters at 24 h by counting crabs and fish present. We found significant avoidance of H. sanguineus in the field by benthic hermit crabs (Pagurus spp.) and significant avoidance of C. maenas by the seaboard goby (Gobiosoma ginsburgi). The grubby (Myoxocephalus aenaeus) avoided neither treatment, probably since it tends to be a predator of invertebrates. H. sanguineus avoided C. maenas treatments, whereas C. maenas did not avoid any treatment. Seasonal deployments in the subtidal indicated cohabitation of a number of benthic species in the LIS, with peak shelter use corresponding with increased predation and likely reproductive activity in spring and summer for green crabs (C. maenas), hermit crabs (Pagurus spp.), seaboard gobies (G. ginsburgi), and grubbies (Myoxocephalus aenaeus).

  14. Community shelter use in response to two benthic decapod predators in the Long Island Sound

    Directory of Open Access Journals (Sweden)

    David M. Hudson

    2016-07-01

    Full Text Available To investigate community shelter effects of two invasive decapod species, Hemigrapsus sanguineus and Carcinus maenas, in the Long Island Sound (LIS, we deployed artificial shelters in the intertidal and immediate subtidal zones. These consisted of five groups during the summer: a control, a resident H. sanguineus male or female group, and a resident C. maenas male or female group. We quantified utilization of the shelters at 24 h by counting crabs and fish present. We found significant avoidance of H. sanguineus in the field by benthic hermit crabs (Pagurus spp. and significant avoidance of C. maenas by the seaboard goby (Gobiosoma ginsburgi. The grubby (Myoxocephalus aenaeus avoided neither treatment, probably since it tends to be a predator of invertebrates. H. sanguineus avoided C. maenas treatments, whereas C. maenas did not avoid any treatment. Seasonal deployments in the subtidal indicated cohabitation of a number of benthic species in the LIS, with peak shelter use corresponding with increased predation and likely reproductive activity in spring and summer for green crabs (C. maenas, hermit crabs (Pagurus spp., seaboard gobies (G. ginsburgi, and grubbies (Myoxocephalus aenaeus.

  15. Inheritance patterns of morphological laterality in mouth opening of zebrafish, Danio rerio.

    Science.gov (United States)

    Hata, Hiroki; Hori, Michio

    2012-01-01

    The inheritance patterns of asymmetry in mouth opening in zebrafish were investigated using crossing experiments. Zebrafish exhibit asymmetric laterality in mouth opening, with each individual having either a leftward (righty) or rightward (lefty) bias. All righty incrosses produced only righty F(1), whereas all lefty incrosses resulted in an F(1) L:R ratio of 2:1. All test crosses between lefty and righty individuals resulted in an F(1) L:R=1:1. These results were consistent with the hereditary pattern for Japanese medaka, three Tanganyikan cichlids, and a Japanese riverine goby. The pattern suggests a one-locus two-allele Mendelian model of inheritance, with the lefty allele being dominant over righty and the dominant homozygote being lethal. To determine the reason for the absence of lefty homozygotes, the survival rates of the offspring were examined according to developmental stage. Survival did not differ among combinations of parent laterality. Thus the mechanism underlying the lethality of the dominant homozygote remains unclear. This study showed that the mouth-opening laterality of zebrafish is genetically determined and that the direction follows a Mendelian inheritance pattern that is shared among cypriniform zebrafish, beloniform medaka, perciform cichlids, and a goby, suggesting a common genetic background in mouth-opening laterality among these species.

  16. Characteristics of Land Use/Cover and Macroscopic Ecological Changes in the Headwaters of the Yangtze River and of the Yellow River over the Past 30 Years

    Directory of Open Access Journals (Sweden)

    Lulu Liu

    2016-03-01

    Full Text Available Based on land use and land cover (LULC datasets in the late 1970s, the early 1990s, 2004 and 2012, we analyzed characteristics of LULC change in the headwaters of the Yangtze River and Yellow River over the past 30 years contrastively, using the transition matrix and LULC change index. The results showed that, in 2012, the LULC in the headwaters of the Yellow River were different compared to those of the headwaters of the Yangtze River, with more grassland and wet- and marshland. In the past 30 years, the grassland and wet- and marshland increasing at the expense of sand, gobi, and bare land and desert were the main LULC change types in the headwaters of the Yangtze River, with the macro-ecological situation experiencing a process of degeneration, slight melioration, and continuous melioration, in that order. In the headwaters of the Yellow River, severe reduction of grassland coverage, shrinkage of wet- and marshland and the consequential expansion of sand, gobi and bare land were noticed. The macro-ecological situation experienced a process of degeneration, obvious degeneration, and slight melioration, in that order, and the overall change in magnitude was more dramatic than that in the headwaters of the Yangtze River. These different LULC change courses were jointly driven by climate change, grassland-grazing pressure, and the implementation of ecological construction projects.

  17. Tactic-specific differences in seminal fluid influence sperm performance.

    Science.gov (United States)

    Locatello, Lisa; Poli, Federica; Rasotto, Maria B

    2013-03-22

    Seminal fluid often makes up a large part of an ejaculate, yet most empirical and theoretical studies on sperm competition have focused on how sperm characteristics (number and quality) affect fertilization success. However, seminal fluid influences own sperm performance and may potentially influence the outcome of sperm competition, by also affecting that of rivals. As a consequence males may be expected to allocate their investment in both sperm and seminal fluid in relation to the potential level of competition. Grass goby (Zosterisessor ophiocephalus) is an external fertilizer with guard-sneaker mating tactics, where sperm competition risk varies according to the tactic adopted. Here, we experimentally manipulated grass goby ejaculates by separately combining sperm and seminal fluid from territorial and sneaker males. While sperm of sneaker and territorial males did not differ in their performance when they interacted with their own seminal fluid only, sperm of sneakers increased their velocity and fertilization rate in the presence of territorial males' seminal fluid. By contrast, sneaker males' seminal fluid had a detrimental effect on the performance of territorial males' sperm. Sperm velocity was unaffected by the seminal fluid of males employing the same tactic, suggesting that seminal fluid's effect on rival-tactic sperm is not based on a self/non-self recognition mechanism. Our findings show that cross interactions of sperm and seminal fluid may influence the fertilization success of competing ejaculates with males investing in both sperm and seminal fluid in response to sperm competition risk.

  18. Stable isotopes reveal diet shift from pre-extinction to reintroduced Przewalski's horses.

    Science.gov (United States)

    Kaczensky, Petra; Burnik Šturm, Martina; Sablin, Mikhail V; Voigt, Christian C; Smith, Steve; Ganbaatar, Oyunsaikhan; Balint, Boglarka; Walzer, Chris; Spasskaya, Natalia N

    2017-07-20

    The Przewalski's horse (Equus ferus przewalskii), the only remaining wild horse within the equid family, is one of only a handful of species worldwide that went extinct in the wild, was saved by captive breeding, and has been successfully returned to the wild. However, concerns remain that after multiple generations in captivity the ecology of the Przewalski's horse and / or the ecological conditions in its former range have changed in a way compromising the species' long term survival. We analyzed stable isotope chronologies from tail hair of pre-extinction and reintroduced Przewalski's horses from the Dzungarian Gobi and detected a clear difference in the isotopic dietary composition. The direction of the dietary shift from being a mixed feeder in winter and a grazer in summer in the past, to a year-round grazer nowadays, is best explained by a release from human hunting pressure. A changed, positive societal attitude towards the species allows reintroduced Przewalski's horses to utilize the scarce, grass-dominated pastures of the Gobi alongside local people and their livestock whereas their historic conspecifics were forced into less productive habitats dominated by browse.

  19. Assessing diet compositions of Lake Ontario predators using fatty acid profiles of prey fishes

    Science.gov (United States)

    Happell, Austin; Pattridge, Robert; Rinchard, Jacques; Walsh, Maureen

    2017-01-01

    Fatty acid profiles are used in food web studies to assess trophic interactions between predator and prey. The present study provides the first comprehensive fatty acid dataset for important prey and predator species in Lake Ontario. Three major prey fish (alewife, rainbow smelt, and round goby) were collected at three sites along the southern shore of Lake Ontario during the spring and fall of 2013, and predator species were collected in similar locations during the summer of 2013. Fatty acid compositions were compared among all prey species, all predator species, and information from both predator and prey was used to infer foraging differences among predators. Seasonal differences in fatty acids were found within each prey species studied. Differences among prey species were greater than any spatio-temporal differences detected within species. Fatty acids of predators revealed species-specific differences that matched known foraging habits. Chinook and Coho salmon, which are known to select alewife as their dominant prey item, had relatively little variation in fatty acid profiles. Conversely, brown trout, lake trout, yellow perch and esocids had highly variable fatty acid profiles and likely highly variable diet compositions. In general, our data suggested three dominant foraging patterns: 1) diet composed of nearly exclusively alewife for Chinook and Coho Salmon; 2) a mixed diet of alewife and round goby for brown and lake trout, and both rock and smallmouth bass; 3) a diet that is likely comprised of forage fishes other than those included in our study for northern pike and chain pickerel.

  20. Survival of fish after escape from a 40 mm stretched diamond mesh trawl codend in the Aegean Sea

    Directory of Open Access Journals (Sweden)

    Faik Ozan Düzbastilar

    2010-11-01

    Full Text Available This study aimed to determine the survival rates of three fish species, the brown comber (Serranus hepatus, black goby (Gobius niger and annular seabream (Diplodus annularis, after their escape from a 40 mm stretched diamond mesh polyethylene (PE codend. Experiments were carried out in the eastern Mediterranean in September 2007 using a conventional bottom trawl with 600 meshes around the mouth. A constant 15 min towing duration was used for all hauls. The towing speed varied between 2.0 and 2.5 knots. Codend covers, supported by two hoops, were used to retain escaping fish. At the end of each haul, these covers were detached from the codend, fixed to the sea floor at depths of 19 to 28 m, and then observed by the divers for a period of seven days. On the eighth day, all of the covers were lifted up and the survivors and mortalities were counted and measured. The mean survival percentages of open codend and experimental cages were found to be 97.1% and 98.3% for brown comber, 69.0% and 77.2% for black goby, and 97.5% and 98.6% for annular seabream respectively.

  1. Indicator polychlorinated biphenyl residues in muscle tissue of fish from Black Sea coast of Bulgaria

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    S. Georgieva

    2016-06-01

    Full Text Available Abstract. Polychlorinated biphenyls (PCBs are characterized by high lipophilicity and persistence in the environment and will therefore bioaccumulate and biomagnify in the food chain. PCBs were determined in muscle tissue of four fish species: goby (Neogobius melanostomus, horse mackerel (Trachurus Mediterraneus ponticus, shad (Alosa pontica pontica and turbot (Psetta maxima maeotica. Samples were collected from Bulgarian Black Sea coast during 2007 – 2011. The PCBs were analyzed in order to examine the time trends of PCB concentrations in fish from Black Sea. The six individual PCBs congeners were determined by capillary gas chromatography system with mass spectrometry detection. PCBs were found in all fish species at concentrations ranging between 2.32 ng/g ww (wet weight and 32.87 ng/g ww in goby and shad, respectively. PCB profiles have been found to be similar in all the fish species tested. The most abundant PCB congeners in fish species were hexa- and heptachlorinated PCBs 138, 153 and 180. PCB 153 was the dominant congener in all fish studied and were found in the range from 0.95 ng/g ww (horse mackerel 2011 to 11.67 ng/g ww (shad 2010. The sum of six indicator PCBs in all fish species did not exceed the European maximum limit of 75 ng/g ww. The levels of PCBs in fish from Bulgarian Black Sea coast were found lower than in fish species from other seas – the Aegean Sea and the Mediterranean Sea.

  2. Otolith microchemistry of tropical diadromous fishes: spatial and migratory dynamics

    Science.gov (United States)

    Smith, William E.; Kwak, Thomas J.

    2014-01-01

    Otolith microchemistry was applied to quantify migratory variation and the proportion of native Caribbean stream fishes that undergo full or partial marine migration. Strontium and barium water chemistry in four Puerto Rico, U.S.A., rivers was clearly related to a salinity gradient; however, variation in water barium, and thus fish otoliths, was also dependent on river basin. Strontium was the most accurate index of longitudinal migration in tropical diadromous fish otoliths. Among the four species examined, bigmouth sleeper Gobiomorus dormitor, mountain mullet Agonostomus monticola, sirajo goby Sicydium spp. and river goby Awaous banana, most individuals were fully amphidromous, but 9-12% were semi-amphidromous as recruits, having never experienced marine or estuarine conditions in early life stages and showing no evidence of marine elemental signatures in their otolith core. Populations of one species, G. dormitor, may have contained a small contingent of semi-amphidromous adults, migratory individuals that periodically occupied marine or estuarine habitats (4%); however, adult migratory elemental signatures may have been confounded with those related to diet and physiology. These findings indicate the plasticity of migratory strategies of tropical diadromous fishes, which may be more variable than simple categorization might suggest.

  3. Assessment of lake sturgeon (Acipenser fulvescens) spawning efforts in the lower St. Clair River, Michigan

    Science.gov (United States)

    Nichols, S. Jerrine; Kennedy, Gregory; Crawford, Eric; Allen, Jeffrey; French, John; Black, Glen; Blouin, Marc; Hickey, James P.; Chernyak, Sergei; Haas, Robert; Thomas, Michael

    2003-01-01

    One of the most threatened remaining populations of lake sturgeon in the Great Lakes is found in the connecting channels between Lake Huron and Lake Erie. Only two spawning grounds are presently known to be active in this region, and both are in the St. Clair River. The spawning reef in the St. Clair River delta has been recently colonized by round gobies (Neogobius melanostomus) in densities up to 25/m2, raising concerns regarding predation on the benthic-oriented eggs and larvae of the sturgeon. Investigations in 1998–1999 showed that while round goby predation does occur, a number of other factors may be equally affecting sturgeon spawning success, including few spawning adults (noted in either year. There were factors other than predation affecting larval survival in 1999. There was a higher silt load on the reef than in 1998 and large numbers of dead larvae were found. Recruitment success from this site could be improved by utilizing techniques to increase the number of eggs on the reef, such as reducing the illegal take of adult fish and by placing eggs in predator-exclusion chambers to increase hatch rate.

  4. Dynamic modeling predicts continued bioaccumulation of polybrominated diphenyl ethers (PBDEs) in smallmouth bass (Micropterus dolomiu) post phase-out due to invasive prey and shifts in predation

    International Nuclear Information System (INIS)

    Wallace, Joshua S.; Blersch, David M.

    2015-01-01

    Unprecedented food chain links between benthic and pelagic organisms are often thought to disrupt traditional contaminant transport and uptake due to changes in predation and mobilization of otherwise sequestered pollutants. A bioaccumulation model for polybrominated diphenyl ethers (PBDEs) is developed to simulate increases in biotic congener loads based upon trophic transfer through diet and gill uptake for a Lake Erie food chain including two invasive species as a benthic-pelagic link. The model utilizes species-specific bioenergetic parameters in a four-level food chain including the green alga Scenedesmus quadricauda, zebra mussels (Dreissena polymorpha), round goby (Appollonia melanostoma), and the smallmouth bass (Micropterus dolomiu). The model was calibrated to current biotic concentrations and predicts an increase in contaminant load by almost 48% in the upper trophic level in two years. Validation to archival data resulted in <2% error from reported values following a two-year simulation. - Highlights: • A dynamic model assesses continued bioaccumulation of PBDEs in predators of invasive prey. • The model incorporates novel benthic-pelagic energy links due to invasive prey. • Increases in total PBDEs in smallmouth bass due to invasive energy pathways are simulated. • The model is validated to archival data obtained prior to invasion of zebra mussels and round goby. - A dynamic model is developed to simulate continued bioaccumulation of polybrominated diphenyl ethers (PBDEs) in smallmouth bass due to emerging benthic-pelagic energy pathways.

  5. Investigation of Three-Dimensional Evolution of East Asian Dust Storm by Modeling and Remote Sensing Measurements

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    Jiawei Li

    2015-01-01

    Full Text Available The three-dimensional evolution of an East Asian dust storm during 23–26 April 2009 was investigated by utilizing a regional air quality model system (RAQMS and satellite measurements. This severe dust storm hit Mt. Tai in east China with daily mean PM10 concentration reaching 1400 μg/m3 and the model captured the PM10 variation reasonably well. Modeled spatial distributions of AOD and vertical profiles of aerosol extinction coefficient during the dust storm were compared with MODIS and CALIPSO data, demonstrating that RAQMS was able to reproduce the 3D structure and the evolution of the dust storm reasonably well. During early days of the dust storm, daily mean dust-induced AOD exceeded 2.0 over dust source regions (the Gobi desert and the Taklamakan desert and was in a range of 1.2–1.8 over the North China Plain, accounting for about 98% and up to 90% of total AOD over corresponding areas, respectively. The top of the dust storm reached about 8 km over east China, with high dust concentration locating at around 40°N. Dust aerosol below 2 km was transported southeastward off the Gobi desert while dust above 2 km was transported out of China along 40°–45°N.

  6. Jaw muscle fiber type distribution in Hawaiian gobioid stream fishes: histochemical correlations with feeding ecology and behavior.

    Science.gov (United States)

    Maie, Takashi; Meister, Andrew B; Leonard, Gerald L; Schrank, Gordon D; Blob, Richard W; Schoenfuss, Heiko L

    2011-12-01

    Differences in fiber type distribution in the axial muscles of Hawaiian gobioid stream fishes have previously been linked to differences in locomotor performance, behavior, and diet across species. Using ATPase assays, we examined fiber types of the jaw opening sternohyoideus muscle across five species, as well as fiber types of three jaw closing muscles (adductor mandibulae A1, A2, and A3). The jaw muscles of some species of Hawaiian stream gobies contained substantial red fiber components. Some jaw muscles always had greater proportions of white muscle fibers than other jaw muscles, independent of species. In addition, comparing across species, the dietary generalists (Awaous guamensis and Stenogobius hawaiiensis) had a lower proportion of white muscle fibers in all jaw muscles than the dietary specialists (Lentipes concolor, Sicyopterus stimpsoni, and Eleotris sandwicensis). Among Hawaiian stream gobies, generalist diets may favor a wider range of muscle performance, provided by a mix of white and red muscle fibers, than is typical of dietary specialists, which may have a higher proportion of fast-twitch white fibers in jaw muscles to help meet the demands of rapid predatory strikes or feeding in fast-flowing habitats. Copyright © 2011 Elsevier GmbH. All rights reserved.

  7. Great Lakes prey fish populations: a cross-basin overview of status and trends based on bottom trawl surveys, 1978-2013

    Science.gov (United States)

    Gorman, Owen T.; Weidel, Brian C.

    2014-01-01

    The assessment of Great Lakes prey fish stocks have been conducted annually with bottom trawls since the 1970s by the Great Lakes Science Center, sometimes assisted by partner agencies. These stock assessments provide data on the status and trends of prey fish that are consumed by important commercial and recreational fishes. Although all these annual surveys are conducted using bottom trawls, they differ among the lakes in the proportion of the lake covered, seasonal timing, trawl gear used, and the manner in which the trawl is towed (across or along bottom contours). Because each assessment is unique, population indices were standardized to the highest value for a time series within each lake for the following prey species: Cisco (Coregonus artedi), Bloater (C. hoyi), Rainbow Smelt (Osmerus mordax), Alewife (Alosa pseudoharengus), and Round Goby (Neogobius melanostomus). In this report, standardized indices are presented in graphical form along with synopses to provide a short, informal cross-basin summary of the status and trends of principal prey fishes. There was basin-wide agreement in the trends of age-1 and older biomass for all prey species, with the highest concordance occurring for coregonids and Rainbow Smelt, and weaker concordance for Alewife. For coregonids, the highest biomass occurred from the mid-1980s to the mid-1990s. Rainbow Smelt biomass declined slowly and erratically during the last quarter century. Alewife biomass was generally higher from the early 1980s through 1990s across the Great Lakes, but since the early 1990s, trends have been divergent across the lakes, though there has been a downward trend in all lakes since 2005. Recently, Lake Huron has shown resurgence in biomass of Bloater, achieving 75% of its maximum record in 2012 due to recruitment of a succession of strong and moderate year classes that appeared in 2005-2011. Also, strong recruitment of the 2010 year class of Alewife has led to a sharp increase in biomass of Alewife in

  8. Biomarker responses to environmental contamination in estuaries: A comparative multi-taxa approach.

    Science.gov (United States)

    Duarte, Irina A; Reis-Santos, Patrick; França, Susana; Cabral, Henrique; Fonseca, Vanessa F

    2017-08-01

    Estuaries are highly productive ecosystems subjected to numerous anthropogenic pressures with consequent environmental quality degradation. In this study, multiple biomarker responses [superoxide dismutase (SOD), catalase (CAT), ethoxyresorufin O-deethylase (EROD) and glutathione S-transferase (GST) activities, as well as lipid peroxidation (LPO) and DNA damage (DNAd)] were determined in two fish (Dicentrarchus labrax and Pomatoschistus microps) and four macroinvertebrate species (Carcinus maenas, Crangon crangon, Hediste diversicolor and Scrobicularia plana) from the Ria de Aveiro and Tejo estuaries over distinct months. Two sites per estuarine system were selected based on anthropogenic pressures and magnitude of environmental contamination. Antioxidant enzyme activities in fish species suggested a ubiquitous response to oxidative stress, while biotransformation and effect biomarkers exhibited higher spatial and temporal variation. In invertebrate species, biotransformation enzyme activity was clearly less variable than in fish evidencing lower xenobiotic transformation capability. Overall, largest biomarker responses were found in the most contaminated sites (Tejo), yet species-specific patterns were evident. These should be factored in multi-taxa approaches, considering that the differential functional traits of species, such as habitat use, life-stage, feeding or physiology can influence exposure routes and biomarker responses. The Integrated Biomarker Response index highlighted patterns in biomarker responses which were not immediately evident when analyzing biomarkers individually. Overall, results provided insights into the complexity of species responses to contamination in naturally varying estuarine environments. Ultimately, multi-taxa and multi-biomarker approaches provide a comprehensive and complementary view of ecosystem health, encompassing diverse forms of biological integration and exposure routes, and allow the validation of results among markers

  9. INVESTIGATION OF LITHOSPHERIC STRUCTURE IN MONGOLIA: INSIGHTS FROM INSAR OBSERVATIONS AND MODELLING

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    Z. Jing

    2017-09-01

    Full Text Available The western Mongolia is a seismically active intracontinental region, with ongoing tectonic deformation and widespread seismicity related to the far-field effects of India-Eurasia collision. During the 20th century, four earthquakes with the magnitude larger than 8 occurred in the western Mongolia and its surrounding regions, providing a unique opportunity to study the geodynamics of intracontinental tectonic deformations. The 1957 magnitude 8.3 Gobi-Altai earthquake is one of the largest seismic events. The deformation pattern of rupture zone associated with this earthquake is complex, involving left-lateral strike-slip and reverse dip-slip faulting on several distinct geological structures in a 264 × 40 km wide zone. To understand the relationship between the observed postseismic surface deformation and the rheological structure of the upper lithosphere, Interferometric Synthetic Aperture Radar (InSAR data are used to study the 1957 earthquake. Then we developed a postseismic model in a spherical, radially layered elastic-viscoelastic Earth based on InSAR results, and further analysed the dominant contribution to the surface deformation. This work is important for understanding not only the regional tectonics, but also the structure and dynamics of the lithosphere. SAR data were acquired from the ERS1/2 and Envisat from 1996 to 2010. Using the Repeat Orbit Interferometry Package (ROI_PAC, 124 postseismic interferograms are produced on four adjacent tracks. By stacking these interferograms, the maximum InSAR line-of-sight deformation rate along the Gobi-Altai fault zone is obtained. The main results are as follows: (1 The maximum InSAR line-of-sight deformation velocity along this large fault zone is about 6 mm/yr; (2 The modelled surface deformation suggests that the viscoelastic relaxation is the most reasonable mechanism to explain the observed surface motion; (3 The optimal model cover the Gobi-Altai seismogenic thickness is 10

  10. Status and trends of prey fish populations in Lake Michigan, 2013

    Science.gov (United States)

    Madenjian, Charles P.; Bunnell, David B.; Desorcie, Timothy J.; Kostich, Melissa Jean; Armenio, Patricia M.; Adams, Jean V.

    2015-01-01

    The U.S. Geological Survey Great Lakes Science Center has conducted lake-wide surveys of the fish community in Lake Michigan each fall since 1973 using standard 12-m bottom trawls towed along contour at depths of 9 to 110 m at each of seven index transects. The resulting data on relative abundance, size and age structure, and condition of individual fishes are used to estimate various population parameters that are in turn used by state and tribal agencies in managing Lake Michigan fish stocks. All seven established index transects of the survey were completed in 2013. The survey provides relative abundance and biomass estimates between the 5-m and 114-m depth contours of the lake (herein, lake-wide) for prey fish populations, as well as burbot, yellow perch, and the introduced dreissenid mussels. Lake-wide biomass of alewives in 2013 was estimated at 29 kilotonnes (kt, 1 kt = 1000 metric tonnes), which was more than three times the 2012 estimate. However, the unusually high standard error associated with the 2013 estimate indicated no significant increase in lake-wide biomass between 2012 and 2013. Moreover, the age distribution of alewives remained truncated with no alewife exceeding an age of 5. The population of age-1 and older alewives was dominated (i.e., 88%) by the 2010 and 2012 year-classes. Record low biomass was observed for deepwater sculpin (1.3 kt) and ninespine stickleback (0.004 kt) in 2013, while bloater (1.6 kt) and rainbow smelt (0.2 kt) biomasses remained at low levels. Slimy sculpin lake-wide biomass was 0.32 kt in 2013, marking the fourth consecutive year of a decline. The 2013 biomass of round goby was estimated at 10.9 kt, which represented the peak estimate to date. Burbot lake-wide biomass (0.4 kt in 2013) has remained below 3 kt since 2001. Numeric density of age-0 yellow perch (i.e., fish per ha, which is indicative of a relatively poor year-class. Lake-wide biomass estimate of dreissenid mussels in 2013 was 23.2 kt. Overall, the total

  11. Dust Propagation and Radiation In the Presence of a Low-level Jet in Central China on March 17, 2010

    Science.gov (United States)

    McDowell, B. K.; Chen, S. H.

    2014-12-01

    Suspended dust in the air can directly change the energy budget in the atmosphere and at the surface through scattering and absorption of radiation. Thus, dust can potentially modify the development of weather systems. To explore the dust-radiation effects on weather systems, a dust model was developed based on the Weather Research and Forecasting (WRF) model. The calculations of dust processes in the WRF dust model include emission, advection, boundary layer mixing, cumulus mixing, dust-radiation interaction, wet scavenging, and sedimentation. Due to a high vertical spatial resolution near the surface a time splitting method was applied to the calculation of dust sedimentation to relax the numerical time step. The "Hexi Corridor" is the historical name given to a string of oases along the northern slope of the Tibetan Plateau that formed a relatively easy transportation route between eastern China and central Asia. As trade developed over the centuries, this route became known as the Silk Road. This corridor also marks the transition from the relatively flat Gobi desert area in northern China to the elevated mountains of the Tibetan Plateau. These mountains present a southern barrier to the paths of dust storms that develop during spring outbreaks of the Mongolian Cyclone. In March of 2010, a series of dust storms developed in the Gobi Desert north of the Hexi Corridor that transported massive amounts of dust eastward to central and northeastern China, Korea and Japan. On March 17 during this event, a low-level jet developed along the northern perimeter of the Plateau, in alignment with upper level winds and the Hexi Corridor. Over the course of the day, a well-defined short-duration dust plume was emitted in the southern Gobi desert area and was transported over 1300 km in a southeast direction, over the Loess Plateau and into the Gansu Province. In this study, the interactions of synoptic conditions with regional topography that led to the development of the low

  12. SALINITAS OPTIMAL UNTUK PENDEDERAN BENIH IKAN BETUTU (Oxyeleotris marmorata

    Directory of Open Access Journals (Sweden)

    Idil Ardi

    2017-01-01

    Full Text Available Ikan betutu (Oxyeleotris marmorata termasuk ikan perairan tawar yang memiliki nilai ekonomis penting dan sangat disukai karena memiliki daging yang tebal, tulangnya sedikit, dan gurih. Salah satu faktor lingkungan yang berpengaruh dalam kegiatan budidaya adalah salinitas. Penelitian bertujuan untuk mendapatkan salinitas optimum dalam pemeliharaan benih ikan betutu yang diharapkan dapat meningkatkan sintasan dan pertumbuhannya. Penelitian menggunakan rancangan acak lengkap (RAL dengan empat perlakukan berdasarkan perbedaan salinitas yaitu kontrol ppt, 1 ppt, 3 ppt, dan 5 ppt. Setiap perlakuan dilakukan tiga kali pengulangan. Hasil penelitian menunjukkan terdapat perbedaan nyata (P<0,05 terhadap laju pertumbuhan spesifik, panjang mutlak, bobot mutlak, dan kadar glukosa darah terhadap kontrol (salinitas 0 ppt setelah dipelihara selama 56 hari. Laju pertumbuhan mutlak, bobot mutlak, dan glukosa darah paling baik dijumpai pada benih yang dipelihara dengan salinitas 3 ppt, yaitu 0,94 ± 0,09%; 2,53 ± 0,35 mm; 37,33 ± 6,28 g; dan 0,06 ± 0,01 g/dL. Pemeliharaan benih betutu membutuhkan air bersalinitas. Untuk mengoptimalkan pertumbuhan dan sintasan air media budidaya disarankan bersalinitas 3 ppt. Sand goby (Oxyeleotris marmorata is one of freshwater fish that has high economic value and is more desired for its thick meat, bone less, and tasteful. Salinity is one of the most important environmental factors in fish culture. The purpose of this study was to determine the optimal salinity concentration on growth and survival of sand goby fish. A completely Randomized Design (CRD was used in this study with four treatments of salinity levels comprising A Control; B 1 ppt; C 3 ppt; D 5 ppt. Each treatment was consisted of three replicates. The result showed significant differences (P<0.05 in specific growth rate, absolute length, absolute weight, and blood glucose among the treatments against control after 56 days cultured. Seed reared under the salinity

  13. Study on atmosphere pollution by PIXE analysis combining with statistical method

    International Nuclear Information System (INIS)

    Zhu Guanghua

    1994-06-01

    Atmospheric aerosol samples were collected using an 8-stage cascade impactor or an automatic time sequence step sampler at Jomo Langma, Zhangye at the edge of Gobi Desert and Beijing. Element concentration were analyzed by PIXE (proton induced X-ray emission) technique. The data were analyzed by APCA (absolute principal component analysis) to determine the principal components. The sources and contribution to the aerosol in the above three regions were discussed. The result shows that the PIXE has high sensitivity, multi-element capability, high speed and non-destruction advantages. APCA analytical method can effectively determine the aerosol components in urban area, and it also can distinguish between local components and remote components in the area far from the pollution resources

  14. Reducing organic contamination of shallow areas in brackish lagoons during rearing fish in cages in polyculture

    Directory of Open Access Journals (Sweden)

    P. Shekk

    2017-07-01

    Full Text Available Purpose. The development of the technology of the controlled rearing of marine fish remains one of the priority strategic trends of development of national mariculture. A study of the possibility of using polyculture for cage culture has a particular interest. Joint cultivation of several species of fish in the same cage, as practice of fish farming has demonstrated, does not have a tangible positive effect. At the same time, the use of cages of special design can provide significant additional fish products through the use of additional aquaculture objects. The ecological state of water areas, where the cages are located, is of great importance. High fish stocking density and the use of artificial feeds can serve as a source of powerful biogenic and organic pollution, which is especially important for shallow water areas with weak water exchange. The purpose of the study is to develop the methods for joint fish production in cage mariculture capable to provide high fish production and to weaken organic pollution of shallow water areas where cage farms are located. Methodology. The studies were conducted in 1999 and 2004. Cages of special design (internal 10 m3 and external 18.75 m3 installed in the brackish Shabolat Lagoon were used for rearing, steelhead trout, haarder, grass goby and round goby in polyculture. The standard aquaculture research methods were used. For express-analysis of environment hydrochemical parameters in cage location area the following devices were used: "ECOTEST-2000 T" (О2, NO2, NO3, NH4, CO2, phosphates, pH; termooksimetr "АJА-101М" (Т; О2; "pH meter-150 M; Refractometer "ATAGO-100" (salinity and water density. Findings. The results of marine fish cultivation in cages in polyculture in the shallow Shabolat lagoon are presented. It has been shown that joint cultivation of salmon, mullet and gobies in specially designed cages in shallow marine lagoons allows using artificial and natural feeds more fully and

  15. Intraabdominal pressure in women during CrossFit exercises and the effect of age and parity.

    Science.gov (United States)

    Gephart, Laura Faye; Doersch, Karen M; Reyes, Michelle; Kuehl, Thomas J; Danford, Jill M

    2018-07-01

    To determine intraabdominal pressure (IAP) in women during CrossFit and to determine whether parity, age, or CrossFit experience affects IAP during CrossFit exercises, we evaluated 10 women: 5 experienced and active CrossFitters and 5 who were not regularly engaged in CrossFit. A Laborie urodynamics abdominal pressure probe with the Goby wireless system measured IAP during 10 repetitions of 13 different CrossFit exercises. Women had a mean age of 36 years. A significant difference was found between mean peak IAP of the 5 parous vs the 5 nulliparous women ( P = 0.009). Experience with CrossFit did not affect mean peak IAP achieved with exercise. In some exercises, there was a significant change in IAP as participants progressed through repetitions ( P = 0.003 for back squats and 0.04 for sit-ups). Participants achieved IAP values that were markedly higher than those previously published.

  16. Small‐scale distribution of fish in offshore windfarms

    DEFF Research Database (Denmark)

    Hansen, Kamilla Sande; Stenberg, Claus; Møller, Peter Rask

    2012-01-01

    Knowledge about small‐scale distribution of fish around turbines in offshore windfarms (OWF) remains relatively scarce. In the present study we used underwater video camera installations to access abundance of fish at 0, 25, and 50 m around the turbine foundations in Middelgrund and Lillgrund OWFs...... in Øresund between Denmark and Sweden in the period August–November 2011. Fish fauna in both localities were dominated in terms of numbers by two‐spotted gobies (Gobiusculus flavescens). Average number of fish observed per hour was a factor 100 higher at Lillgrund and a factor of 2 higher at Middelgrund at 0...... on fish fauna compared to OWFs in areas with heterogeneous sediment. Furthermore, the effect of OWFs on fish appears to be of a much smaller scale than previously thought...

  17. Feeding ecology and trophic relationships of fish species in the lower Guadiana River Estuary and Castro Marim e Vila Real de Santo António Salt Marsh

    Science.gov (United States)

    Sá, Rita; Bexiga, Constança; Veiga, Pedro; Vieira, Lina; Erzini, Karim

    2006-10-01

    In this study we analyze the feeding ecology and trophic relationships of some of the main fish species (Soleidae, Moronidae, Mullidae, Sparidae, Mugilidae, and Batrachoididae) of the lower Estuary of the Guadiana River and the Castro Marim e Vila Real de Santo António Salt Marsh. We examined the stomachs of 1415 fish caught monthly between September 2000 and August 2001. Feeding indices and coefficients were determined and used along with the results of multivariate analysis to develop diagrams of trophic interactions (food webs). Results show that these species are largely opportunistic predators. The most important prey items are amphipods, gobies (Gobiidae), shrimps ( Palaemon serratus and Crangon crangon), and polychaete worms. The lower Estuary and associated salt marshes are important nurseries and feeding grounds for the species studied. In this area, it is therefore important to monitor the effects of changes in river runoff, nutrient input, and temperature that result from construction of the Alqueva Dam upstream.

  18. Spatial extent and dynamics of dam impacts on tropical island freshwater fish assemblages

    Science.gov (United States)

    Cooney, Patrick B.; Kwak, Thomas J.

    2013-01-01

    Habitat connectivity is vital to the persistence of migratory fishes. Native tropical island stream fish assemblages composed of diadromous species require intact corridors between ocean and riverine habitats. High dams block fish migration, but low-head artificial barriers are more widespread and are rarely assessed for impacts. Among all 46 drainages in Puerto Rico, we identified and surveyed 335 artificial barriers that hinder fish migration to 74.5% of the upstream habitat. We also surveyed occupancy of native diadromous fishes (Anguillidae, Eleotridae, Gobiidae, and Mugilidae) in 118 river reaches. Occupancy models demonstrated that barriers 2 meters (m) high restricted nongoby fish migration and extirpated those fish upstream of 4-m barriers. Gobies are adapted to climbing and are restricted by 12-m barriers and extirpated upstream of 32-m barriers. Our findings quantitatively illustrate the extensive impact of low-head structures on island stream fauna and provide guidance for natural resource management, habitat restoration, and water development strategies.

  19. Energy from the desert. Very large scale photovoltaic systems: socio-economic, financial, technical and environmental aspects. Executive summary

    Energy Technology Data Exchange (ETDEWEB)

    Kurokawa, K.; Ito, M.; Komoto, K.; Vleuten, P. van der; Faiman, D. (eds.)

    2009-05-15

    This executive summary report for the International Energy Agency (IEA) summarises the objectives and concepts of very large scale photovoltaic power generation (VLS-PV) systems and takes a look at the socio-economic, financial and technical aspects involved as well as the environmental impact of such systems. Potential benefits for desert communities, agricultural development and desalination of water are topics that are looked at. The potential of VLS-PV, its energy payback time and CO{sub 2} emission rates are discussed. Case studies for the Sahara and the Gobi Dessert areas are discussed. A VLS-PV roadmap is proposed and scenarios are discussed. Finally, conclusions are drawn and recommendations are made.

  20. Compression of FASTQ and SAM format sequencing data.

    Directory of Open Access Journals (Sweden)

    James K Bonfield

    Full Text Available Storage and transmission of the data produced by modern DNA sequencing instruments has become a major concern, which prompted the Pistoia Alliance to pose the SequenceSqueeze contest for compression of FASTQ files. We present several compression entries from the competition, Fastqz and Samcomp/Fqzcomp, including the winning entry. These are compared against existing algorithms for both reference based compression (CRAM, Goby and non-reference based compression (DSRC, BAM and other recently published competition entries (Quip, SCALCE. The tools are shown to be the new Pareto frontier for FASTQ compression, offering state of the art ratios at affordable CPU costs. All programs are freely available on SourceForge. Fastqz: https://sourceforge.net/projects/fastqz/, fqzcomp: https://sourceforge.net/projects/fqzcomp/, and samcomp: https://sourceforge.net/projects/samcomp/.

  1. 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

  2. Development of standard weight equations for Caribbean and Gulf of Mexico amphidromous fishes

    Science.gov (United States)

    Cooney, Patrick B.; Kwak, Thomas J.

    2010-01-01

    We collected and compiled length and weight information from four countries and one commonwealth to develop standard weight (Ws) equations for three amphidromous fish species native to the Caribbean and Gulf of Mexico regions: mountain mullet Agonostomus monticola (N = 9,768 individuals, 52 populations), river goby Awaous banana (N = 1,847 individuals, 62 populations), and bigmouth sleeper Gobiomorus dormitor (N = 2,983 individuals, 53 populations). Linear and quadratic Ws equations for three quartiles (25%, median, 75%) are presented for these three species. The length-weight relationship from eight lentic bigmouth sleeper populations was significantly different from that of lotic populations, reflecting higher weights of juvenile fish (sport fisheries and allow ecological assessment based on fish condition.

  3. Application effect of TEM sounding survey on prospecting and target area selection of sandstone-type uranium deposits

    International Nuclear Information System (INIS)

    He Jianguo; Liang Shanming; Zhao Cuiping

    2006-01-01

    Based on the results of transient electromagnetic (TEM) sounding survey during recent years regional geological reconnaissance with drilling (1:250000), the application effect of TEM sounding survey during regional reconnaissance is summarized in this paper. It is suggested that the data of TEM sounding are useful in judging hydrodynamic conditions of groundwater and determining favorable areas for uranium ore-formation; TEM sounding in large areas may be proper for prospecting in gobi-desert areas and be beneficial for regional reconnaissance and target area selection, and may reduce the target area and provide basis for further drilling program. It is of popularized significance in the prospecting for sandstone-type uranium deposits. (authors)

  4. Evaluating dispersal potential of an invasive fish by the use of aerobic scope and osmoregulation capacity

    DEFF Research Database (Denmark)

    Behrens, Jane W.; Deurs, Mikael van; Christensen, Emil Aputsiaq Flindt

    2017-01-01

    factors such as presence of predators, competitors, and parasites. Early prediction of dispersal potential and future 'area of impact' is challenging, but also a great asset in taking appropriate management actions. Aerobic scope (AS) in fish has been linked to various fitness-related parameters, and may...... waters is unknown to date. We show that AS in round goby is reduced by 30% and blood plasma osmolality increased (indicating reduced capacity for osmoregulation) at salinities approaching oceanic conditions, following slow ramping (5 PSU per week) and subsequent long-term acclimation to salinities...... ranging between 0 and 30 PSU (8 days at final treatment salinities before blood plasma osmolality measurements, 12-20 additional days before respirometry). Survival was also reduced at the highest salinities yet a significant proportion (61%) of the fish survived at 30 PSU. Reduced physiological...

  5. Columbus State University Global Observation and Outreach for the 2012 Transit of Venus

    Science.gov (United States)

    Perry, Matthew; McCarty, C.; Bartow, M.; Hood, J. C.; Lodder, K.; Johnson, M.; Cruzen, S. T.; Williams, R. N.

    2013-01-01

    Faculty, staff and students from Columbus State University’s (CSU’s) Coca-Cola Space Science Center presented a webcast of the 2012 Transit of Venus from three continents to a global audience of 1.4 million unique viewers. Team members imaged the transit with telescopes using white-light, hydrogen-alpha, and calcium filters, from Alice Springs, Australia; the Gobi Desert, Mongolia; Bryce Canyon, UT; and Columbus, GA. Images were webcast live during the transit in partnership with NASA’s Sun-Earth Day program, and Science Center staff members were featured on NASA TV. Local members of the public were brought in for a series of outreach initiatives, in both Georgia and Australia, before and during the transit. The data recorded from the various locations have been archived for use in demonstrating principles such as the historical measurement of the astronomical unit.

  6. Seasonal and interannual effects of hypoxia on fish habitat quality in central Lake Erie

    Science.gov (United States)

    Arend, Kristin K.; Beletsky, Dmitry; DePinto, Joseph; Ludsin, Stuart A.; Roberts, James J.; Rucinski, Daniel K.; Scavia, Donald; Schwab, David J.; Höök, Tomas O.

    2011-01-01

    1. Hypoxia occurs seasonally in many stratified coastal marine and freshwater ecosystems when bottom dissolved oxygen (DO) concentrations are depleted below 2–3 mg O2 L-1. 2. We evaluated the effects of hypoxia on fish habitat quality in the central basin of Lake Erie from 1987 to 2005, using bioenergetic growth rate potential (GRP) as a proxy for habitat quality. We compared the effect of hypoxia on habitat quality of (i) rainbow smelt, Osmerus mordax mordax Mitchill (young-of-year, YOY, and adult), a cold-water planktivore, (ii) emerald shiner, Notropis atherinoides Rafinesque (adult), a warm-water planktivore, (iii) yellow perch, Perca flavescens Mitchill (YOY and adult), a cool-water benthopelagic omnivore and (iv) round goby Neogobius melanostomus Pallas (adult) a eurythermal benthivore. Annual thermal and DO profiles were generated from 1D thermal and DO hydrodynamics models developed for Lake Erie’s central basin. 3. Hypoxia occurred annually, typically from mid-July to mid-October, which spatially and temporally overlaps with otherwise high benthic habitat quality. Hypoxia reduced the habitat quality across fish species and life stages, but the magnitude of the reduction varied both among and within species because of the differences in tolerance to low DO levels and warm-water temperatures. 4. Across years, trends in habitat quality mirrored trends in phosphorus concentration and water column oxygen demand in central Lake Erie. The per cent reduction in habitat quality owing to hypoxia was greatest for adult rainbow smelt and round goby (mean: -35%), followed by adult emerald shiner (mean: -12%), YOY rainbow smelt (mean: -10%) and YOY and adult yellow perch (mean: -8.5%). 5. Our results highlight the importance of differential spatiotemporally interactive effects of DO and temperature on relative fish habitat quality and quantity. These effects have the potential to influence the performance of individual fish species as well as population dynamics

  7. PENGARUH PERBEDAAN SUHU AIR PADA PEMELIHARAAN BENIH IKAN BETUTU (Oxyeleotris marmorata Blkr DENGAN SISTEM RESIRKULASI

    Directory of Open Access Journals (Sweden)

    Imam Taufik

    2016-11-01

    Full Text Available Penelitian bertujuan untuk menentukan suhu air yang optimal pada pemeliharaan benih ikan betutu dengan sistem resirkulasi air. Wadah penelitian: 16 unit bak kayu berlapis plastik (1,5 m x 0,7 m x 0,5 m diisi air 300 L yang masing-masing menggunakan bak filter, ditempatkan dalam ruang terlindung dan dilengkapi dengan aerasi. Hewan uji: benih ikan betutu ukuran fingerling (0,65±0,118 g/ekor, padat tebar 1 ekor/5 liter air, diberi makanan alami berupa cacing dan ikan seribu secara berlebih, dengan waktu pemeliharaan 12 minggu. Perlakuan berupa perbedaan suhu air, yaitu: (a 26oC; (b 29oC; (c 32oC; dan (d 24oC–28oC. Parameter yang diukur: sintasan, pertumbuhan, dan produktivitas benih ikan betutu serta sifat fisika-kimia air pemeliharaan. Hasil pene-litian menunjukkan bahwa suhu air paling baik adalah 29oC dan 32oC dan secara nyata (P<0,05 berpengaruh terhadap sintasan, pertumbuhan, dan produktivitas ikan betutu. The objective of the research was know the optimum water temperature in rearing of sand goby fingerlings. Sixteen containers of 1.5 m x 0.7 m x 0.5 m in size were used in this experiment. Each container was stocked with 1 fish/5 L. Average fish weight of 0.65±0.118 gram. Four different water temperatures were applied i.e: (a 26oC; (b 29oC; (c 32oC; and (d 24oC-28oC. The result showed that the water temperature of 29oC and 32oC gave the best result on survival rate, growth rate, and productifity of sand goby.

  8. Fluctuating asymmetry in evaluating the developmental instability of Glossogobius giuris (Hamilton, 1822 from Lake Mainit, Surigao del Norte, Philippines

    Directory of Open Access Journals (Sweden)

    C.C.D.Joseph

    2016-06-01

    Full Text Available This study was conducted to assess the status of Lake Mainit by using fluctuating asymmetry in the populations of Glossogobius giuris. A total of 200 G. giuris was collected with 100 per sex. All the samples were placed in a flat styrofoam for the pinning of its fins to make it wider and to clearly see the samples point of origin for the land-marking process. 10% Formalin was applied in all the fins of the fish samples to make it hardened using a small brush. Twenty (20 landmarks were used to analyze the body shape of the fish. Several studies proved that FA can be used to directly assess water quality and the overall status of the ecosystem. Using thin-plate spline (TPS series, landmark analyses were obtained and subjected to Symmetry and Asymmetry in Geometric Data (SAGE software. Results in Procrustes ANOVA showed that individual symmetry showed a highly significant difference (P = 0.00 as well as Sides (Directional Asymmetry and Interaction (Fluctuating Asymmetry in the study area. All the samples showed FA in both sexes. The results of Principal Component Scores displayed a higher percentage in female (69.2797% than male (63.9214% from Lake Mainit. Variations are almost found in all the body part of the goby in female and male gobies except for anterior insertion of second dorsal fin and superior margin of the preoperculum. Females have a higher fluctuating asymmetry than in males. Females spawn and males protect the eggs from any predators. In this case, females are more susceptible to stress because they have to forage in order to compensate the energy used up during spawning. Males are less susceptible because they usually stay on the nesting ground, and don't have to cover far distances in finding food. This study validates the use of FA in determining the status of the fishes caught connecting to what the status of the environment is based on the result.

  9. Seasonal variation in male alternative reproductive tactics.

    Science.gov (United States)

    Monroe, M J; Amundsen, T; Utne-Palm, A C; Mobley, K B

    2016-12-01

    Genetic parentage analyses reveal considerable diversity in alternative reproductive behaviours (e.g. sneaking) in many taxa. However, little is known about whether these behaviours vary seasonally and between populations. Here, we investigate seasonal variation in male reproductive behaviours in a population of two-spotted gobies (Gobiusculus flavescens) in Norway. Male two-spotted gobies guard nests, attract females and care for fertilized eggs. We collected clutches and nest-guarding males early and late in the breeding season in artificial nests and used microsatellite markers to reconstruct parentage from a subset of offspring from each nest. We hypothesized that mating, reproductive success and sneaking should be more prevalent early in the breeding season when competition for mates among males is predicted to be higher. However, parentage analyses revealed similar values of mating, reproductive success and high frequencies of successful sneaking early (30% of nests) and late (27% of nests) in the season. We also found that multiple females with eggs in the same nest were fertilized by one or more sneaker males, indicating that some males in this population engage in a satellite strategy. We contrast our results to previous work that demonstrates low levels of cuckoldry in a population in Sweden. Our results demonstrate marked stability in both the genetic mating system and male alternative reproductive tactics over the breeding season. However, sneaking rates may vary geographically within a species, likely due to local selection influencing ecological factors encountered at different locations. © 2016 European Society For Evolutionary Biology. Journal of Evolutionary Biology © 2016 European Society For Evolutionary Biology.

  10. Seminal fluid enhances competitiveness of territorial males' sperm in a fish with alternative male reproductive tactics.

    Science.gov (United States)

    Poli, Federica; Locatello, Lisa; Rasotto, Maria B

    2018-05-29

    The most common adaptation to sperm competition in males is represented by an increase in the sperm number and/or quality released at mating, to raise their probability of egg fertilization. However, rapidly mounting evidence highlights that seminal fluid may directly influence the competitive fertilization success of a male by affecting either own and/or rival sperm performances. In the black goby, Gobius niger , an external fertilizer with guard-sneaker mating tactics and high sperm competition level, sneaker males' ejaculates contain less seminal fluid and more sperm, that are also of better quality, than those of territorial males. However, territorial males, gain a higher paternity success inside natural nests. Here, we ask whether the seminal fluid can contribute to territorial males' reproductive success by enhancing their sperm performances and/or by decreasing those of sneaker males. Using sperm and seminal fluid manipulation and in vitro fertilization tests, we found that own seminal fluid influences the velocity and fertilization ability of sperm only in territorial males, making them as faster as those of sneakers and with similar fertilization rate. Moreover, both sneaker and territorial males' sperm remain unaffected by the seminal fluid of rival males. Thus, black goby males respond to the different level of sperm competition faced by differently allocating in sperm and non-sperm components of the ejaculate, with sneakers primarily investing in sperm of intrinsic high quality and territorial males relying on the effect of seminal fluid to increase the lower intrinsic quality of their sperm. © 2018. Published by The Company of Biologists Ltd.

  11. 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.

  12. Palinspastic reconstruction and geological evolution of Permian residual marine basins bordering China and Mongolia

    Directory of Open Access Journals (Sweden)

    Gen-Yao Wu

    2014-04-01

    Full Text Available One main feature of the tectono-paleogeographic evolution of the southern branch of the Paleo-Asian Ocean was that there developed residual marine basins in former backarc/forearc regions after the disappearance of oceanic crust. The paper illustrates the viewpoint taking the evolution of Dalandzadgad and Solonker oceanic basins as examples. The Dalandzadgad ocean subducted southwards during the Silurian-Devonian, created an intra-oceanic arc and a backarc basin in southern Mongolia. In addition, a continent marginal arc formed along the national boundary between China and Mongolia, the south of which was a backarc basin. The oceanic basin closed and arc–arc (continent collision occurred during the early Early Permian, followed by two residual marine basins developing in the former backarc regions, named the South Gobi Basin in southern Mongolia and the Guaizihu Basin in western Inner Mongolia. The Solonker ocean subducted southwards and finally disappeared during the early Middle Permian. Afterwards, two residual marine basins occurred in northern China, the Zhesi Basin being situated in the former backarc region and the Wujiatun Basin in the former forearc region. The late Middle Permian was the most optimum period for the developing residual marine basins, when they covered a vast area. The basin evolution differentiated during the early Late Permian, with a general trend of uplift in the east and of subsidence in the west. The Upper Permian in the South Gobi Basin was characterized by coal-bearing strata hosting economically valuable coal fields. A transgression invaded westwards and the Chandmani-Bayanleg Basin was created in southwest Mongolia during the middle-late stage of the Late Permian. Correspondingly, the coal formation entered a flourishing time, with thick coal beds and sedimentary interbeds. All of these basins, namely, both the marine and nonmarine residual basins, reversed and closed by the end of Permian.

  13. Effects of season, sex and body size on the feeding ecology of turtle-headed sea snakes ( Emydocephalus annulatus) on IndoPacific inshore coral reefs

    Science.gov (United States)

    Goiran, C.; Dubey, S.; Shine, R.

    2013-06-01

    In terrestrial snakes, many cases of intraspecific shifts in dietary habits as a function of predator sex and body size are driven by gape limitation and hence are most common in species that feed on relatively large prey and exhibit a wide body-size range. Our data on sea snakes reveal an alternative mechanism for intraspecific niche partitioning, based on sex-specific seasonal anorexia induced by reproductive activities. Turtle-headed sea snakes ( Emydocephalus annulatus) on coral reefs in the New Caledonian Lagoon feed entirely on the eggs of demersal-spawning fishes. DNA sequence data (cytochrome b gene) on eggs that we palpated from stomachs of 37 snakes showed that despite this ontogenetic stage specialization, the prey comes from a taxonomically diverse array of species including damselfish (41 % of samples, at least 5 species), blennies (41 %, 4 species) and gobies (19 %, 5 species). The composition of snake diets shifted seasonally (with damselfish dominating in winter but not summer), presumably reflecting seasonality of fish reproduction. That seasonal shift affects male and female snakes differently, because reproduction is incompatible with foraging. Adult female sea snakes ceased feeding when they became heavily distended with developing embryos in late summer, and males ceased feeding while they were mate searching in winter. The sex divergence in foraging habits may be amplified by sexual size dimorphism; females grow larger than males, and larger snakes (of both sexes) feed more on damselfish (which often lay their eggs in exposed sites) than on blennies and gobies (whose eggs are hidden within narrow crevices). Specific features of reproductive biology of coral reef fish (seasonality and nest type) have generated intraspecific niche partitioning in these sea snakes, by mechanisms different from those that apply to terrestrial snakes.

  14. Diurnal and seasonal variations in carbon dioxide exchange in ecosystems in the Zhangye oasis area, Northwest China.

    Science.gov (United States)

    Zhang, Lei; Sun, Rui; Xu, Ziwei; Qiao, Chen; Jiang, Guoqing

    2015-01-01

    Quantifying carbon dioxide exchange and understanding the response of key environmental factors in various ecosystems are critical to understanding regional carbon budgets and ecosystem behaviors. For this study, CO2 fluxes were measured in a variety of ecosystems with an eddy covariance observation matrix between June 2012 and September 2012 in the Zhangye oasis area of Northwest China. The results show distinct diurnal variations in the CO2 fluxes in vegetable field, orchard, wetland, and maize cropland. Diurnal variations of CO2 fluxes were not obvious, and their values approached zero in the sandy desert, desert steppe, and Gobi ecosystems. Additionally, daily variations in the Gross Primary Production (GPP), Ecosystem Respiration (Reco) and Net Ecosystem Exchange (NEE) were not obvious in the sandy desert, desert steppe, and Gobi ecosystems. In contrast, the distributions of the GPP, Reco, and NEE show significant daily variations, that are closely related to the development of vegetation in the maize, wetland, orchard, and vegetable field ecosystems. All of the ecosystems are characterized by their carbon absorption during the observation period. The ability to absorb CO2 differed significantly among the tested ecosystems. We also used the Michaelis-Menten equation and exponential curve fitting methods to analyze the impact of Photosynthetically Active Radiation (PAR) on the daytime CO2 flux and impact of air temperature on Reco at night. The results show that PAR is the dominant factor in controlling photosynthesis with limited solar radiation, and daytime CO2 assimilation increases rapidly with PAR. Additionally, the carbon assimilation rate was found to increase slowly with high solar radiation. The light response parameters changed with each growth stage for all of the vegetation types, and higher light response values were observed during months or stages when the plants grew quickly. Light saturation points are different for different species. Nighttime

  15. Model development of dust emission and heterogeneous chemistry within the Community Multiscale Air Quality modeling system and its application over East Asia

    Directory of Open Access Journals (Sweden)

    X. Dong

    2016-07-01

    Full Text Available The Community Multiscale Air Quality (CMAQ model has been further developed in terms of simulating natural wind-blown dust in this study, with a series of modifications aimed at improving the model's capability to predict the emission, transport, and chemical reactions of dust. The default parameterization of initial threshold friction velocity constants are revised to correct the double counting of the impact of soil moisture in CMAQ by the reanalysis of field experiment data; source-dependent speciation profiles for dust emission are derived based on local measurements for the Gobi and Taklamakan deserts in East Asia; and dust heterogeneous chemistry is also implemented. The improved dust module in the CMAQ is applied over East Asia for March and April from 2006 to 2010. The model evaluation result shows that the simulation bias of PM10 and aerosol optical depth (AOD is reduced, respectively, from −55.42 and −31.97 % by the original CMAQ to −16.05 and −22.1 % by the revised CMAQ. Comparison with observations at the nearby Gobi stations of Duolun and Yulin indicates that applying a source-dependent profile helps reduce simulation bias for trace metals. Implementing heterogeneous chemistry also results in better agreement with observations for sulfur dioxide (SO2, sulfate (SO42−, nitric acid (HNO3, nitrous oxides (NOx, and nitrate (NO3−. The investigation of a severe dust storm episode from 19 to 21 March 2010 suggests that the revised CMAQ is capable of capturing the spatial distribution and temporal variation of dust. The model evaluation also indicates potential uncertainty within the excessive soil moisture used by meteorological simulation. The mass contribution of fine-mode particles in dust emission may be underestimated by 50 %. The revised CMAQ model provides a useful tool for future studies to investigate the emission, transport, and impact of wind-blown dust over East Asia and elsewhere.

  16. Do Community-based Institutions Build Resilience to Climate Change in Mongolia?

    Science.gov (United States)

    Fernandez-Gimenez, M.

    2012-12-01

    Climate change impacts are inherently local, yet relatively little is known about the role of local people and institutions in adapting to climate change. Mongolia has experienced one of the strongest warming trends on Earth over the past 40 years, associated declines in streamflow, and increases in the frequency of extreme winter weather events. Environmental changes are compounded by rapid political, economic and social transformations beginning in 1990. We investigate the complex interactions of social, ecological and climate changes across multiple levels from local to regional to national. We hypothesize that community-based institutions increase resilience by strengthening self-regulating feedbacks between social and ecological systems through development and enforcement of formal management rules, implementation of innovative management practices, strengthening of social networks and information exchange within and across levels of social organization, and enhanced monitoring. These result in better ecological and socio-economic conditions and greater adaptive capacity in areas under formal community-based management compared to adjacent areas without formal community management institutions. Evaluation of this hypothesis involves integrated collection and analysis of quantitative and qualitative ecological, social and hydro-climatic data at household, community and regional levels of spatial and social organization. Here, we present preliminary results evaluating these hypotheses from 10 counties (soum) in 3 provinces (aimag) in the Gobi desert-steppe of southern Mongolia based on household-level social data and plot-level ecological data representing. Our initial findings support the hypothesis that community-based institutions are associated with greater household adaptive capacity and healthier pasture ecological conditions, characterized by greater perennial vegetation cover and biomass, especially in the functional group most important for livestock

  17. PENGARUH SISTEM PERGANTIAN AIR YANG BERBEDA PADA PEMELIHARAAN BENIH IKAN BETUTU (Oxyeleotris marmorata Blkr.

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    Imam Taufik

    2016-12-01

    Full Text Available Penelitian bertujuan untuk mengetahui sistem pergantian air yang paling baik pada pemeliharaan benih ikan betutu. Wadah penelitian: 12 unit bak kayu berlapis plastik (1,9m x 0,8m x 0,5m diisi air 500 L, ditempatkan dalam ruang terlindung dan dilengkapi dengan aerasi. Hewan uji: benih ikan betutu ukuran bobot 0,96±0,08 g/ekor, padat tebar 1 ekor/5 liter air, diberi pakan alami secara berlebih dengan waktu pemeliharaan selama 12 minggu. Perlakuan berupa perbedaan sistem pergantian air: (a resirkulasi, (b semi-statis, dan (c continous flow. Parameter yang diukur: sintasan, pertumbuhan, dan produktivitas benih ikan betutu serta sifat fisika-kimia air pemeliharaan. Hasil penelitian menunjukkan bahwa pergantian air dengan sistem resirkulasi memberikan sintasan yang paling baik terhadap benih ikan betutu (33,0% dibanding continous flow (28,3% dan berbeda nyata (P0,05 dengan nilai secara berturut-turut sebesar: 1,41%; 1,31%; dan 1,50%. The aim of this experiment is to obtain the information on survival rate and growth of sand goby fries. The experiment was conducted at research station CibalagungBogor. Twelve container of 1.9m x 0.8m x 0.5m were used in this experiment, each container was stocked with 1 fish/5L of sand goby fry with 0.96±0.08 gram weight. Three different water exchange were aplied i.e (a recirculation, (b semi static, and (c continous flow. Each treatment was done in three replicates. The result showed that the recirculation gave the best result on survival rate (33.0% compared with continous flow (28.3% and significantly different from semi static (21.3%.

  18. Evaluating dispersal potential of an invasive fish by the use of aerobic scope and osmoregulation capacity.

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    Jane W Behrens

    Full Text Available Non-indigenous species (NIS can impact marine biodiversity and ecosystem structure and function. Once introduced into a new region, secondary dispersal is limited by the physiology of the organism in relation to the ambient environment and by complex interactions between a suite of ecological factors such as presence of predators, competitors, and parasites. Early prediction of dispersal potential and future 'area of impact' is challenging, but also a great asset in taking appropriate management actions. Aerobic scope (AS in fish has been linked to various fitness-related parameters, and may be valuable in determining dispersal potential of aquatic invasive species in novel environments. Round goby, Neogobius melanostomus, one of the most wide-ranging invasive fish species in Europe and North America, currently thrives in brackish and fresh water, but its ability to survive in high salinity waters is unknown to date. We show that AS in round goby is reduced by 30% and blood plasma osmolality increased (indicating reduced capacity for osmoregulation at salinities approaching oceanic conditions, following slow ramping (5 PSU per week and subsequent long-term acclimation to salinities ranging between 0 and 30 PSU (8 days at final treatment salinities before blood plasma osmolality measurements, 12-20 additional days before respirometry. Survival was also reduced at the highest salinities yet a significant proportion (61% of the fish survived at 30 PSU. Reduced physiological performance at the highest salinities may affect growth and competitive ability under oceanic conditions, but to what extent reduced AS and osmoregulatory capacity will slow the current 30 km year-1 rate of advance of the species through the steep salinity gradient from the brackish Baltic Sea and into the oceanic North Sea remains speculative. An unintended natural experiment is in progress to test whether the rate of advance slows down. At the current rate of advance the

  19. Predator diversity effects in an exotic freshwater food web.

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    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.

  20. Contest experience and body size affect different types of contest decisions.

    Science.gov (United States)

    Chen, Yu-Ju; Hsu, Yuying

    2016-11-01

    This study examined the relative importance of contest experience and size differences to behavioral decisions over the course of contests. Using a mangrove rivulus fish, Kryptolebias marmoratus, we showed that although contest experience and size differences jointly determined contest outcomes, they affected contestants' interactions at different stages of contests. Contest experience affected behavioral decisions at earlier stages of contests, including the tendency and latency to launch attacks, the tendency to escalate contests into mutual attacks and the outcome of non-escalated contests. Once contests were escalated into mutual attacks, the degree of size difference affected the fish's persistence in escalation and chance of winning, but contest experience did not. These results support the hypothesis that contest experience modifies individuals' estimation of their fighting ability rather than their actual strength. Furthermore, (1) in contests between two naïve contestants, more than 60 % of fish that were 2-3 mm smaller than their opponent escalated the contest to physical fights, even though their larger opponents eventually won 92 % of escalated fights and (2) fish with a losing experience were very likely to retreat in the face of an opponent 2-3 mm smaller than them without escalating. The result that a 2-3 mm size advantage could not offset the influence of a losing experience on the tendency to escalate suggests that, as well as depending on body size, the fish's physical strength is influenced by other factors which require further investigation.

  1. Permanent Genetic Resources added to Molecular Ecology Resources database 1 January 2009-30 April 2009.

    Science.gov (United States)

    Abercrombie, L G; Anderson, C M; Baldwin, B G; Bang, I C; Beldade, R; Bernardi, G; Boubou, A; Branca, A; Bretagnolle, F; Bruford, M W; Buonamici, A; Burnett, R K; Canal, D; Cárdenas, H; Caullet, C; Chen, S Y; Chun, Y J; Cossu, C; Crane, C F; Cros-Arteil, S; Cudney-Bueno, R; Danti, R; Dávila, J A; Della Rocca, G; Dobata, S; Dunkle, L D; Dupas, S; Faure, N; Ferrero, M E; Fumanal, B; Gigot, G; González, I; Goodwin, S B; Groth, D; Hardesty, B D; Hasegawa, E; Hoffman, E A; Hou, M L; Jamsari, A F J; Ji, H J; Johnson, D H; Joseph, L; Justy, F; Kang, E J; Kaufmann, B; Kim, K S; Kim, W J; Koehler, A V; Laitung, B; Latch, P; Liu, Y D; Manjerovic, M B; Martel, E; Metcalfe, S S; Miller, J N; Midgley, J J; Migeon, A; Moore, A J; Moore, W L; Morris, V R F; Navajas, M; Navia, D; Neel, M C; De Nova, P J G; Olivieri, I; Omura, T; Othman, A S; Oudot-Canaff, J; Panthee, D R; Parkinson, C L; Patimah, I; Pérez-Galindo, C A; Pettengill, J B; Pfautsch, S; Piola, F; Potti, J; Poulin, R; Raimondi, P T; Rinehart, T A; Ruzainah, A; Sarver, S K; Scheffler, B E; Schneider, A R R; Silvain, J F; Siti Azizah, M N; Springer, Y P; Stewart, C N; Sun, W; Tiedemann, R; Tsuji, K; Trigiano, R N; Vendramin, G G; Wadl, P A; Wang, L; Wang, X; Watanabe, K; Waterman, J M; Weisser, W W; Westcott, D A; Wiesner, K R; Xu, X F; Yaegashi, S; Yuan, J S

    2009-09-01

    This article documents the addition of 283 microsatellite marker loci to the Molecular Ecology Resources Database. Loci were developed for the following species: Agalinis acuta; Ambrosia artemisiifolia; Berula erecta; Casuarius casuarius; Cercospora zeae-maydis; Chorthippus parallelus; Conyza canadensis; Cotesia sesamiae; Epinephelus acanthistius; Ficedula hypoleuca; Grindelia hirsutula; Guadua angustifolia; Leucadendron rubrum; Maritrema novaezealandensis; Meretrix meretrix; Nilaparvata lugens; Oxyeleotris marmoratus; Phoxinus neogaeus; Pristomyrmex punctatus; Pseudobagrus brevicorpus; Seiridium cardinale; Stenopsyche marmorata; Tetranychus evansi and Xerus inauris. These loci were cross-tested on the following species: Agalinis decemloba; Agalinis tenella; Agalinis obtusifolia; Agalinis setacea; Agalinis skinneriana; Cercospora zeina; Cercospora kikuchii; Cercospora sorghi; Mycosphaerella graminicola; Setosphaeria turcica; Magnaporthe oryzae; Cotesia flavipes; Cotesia marginiventris; Grindelia Xpaludosa; Grindelia chiloensis; Grindelia fastigiata; Grindelia lanceolata; Grindelia squarrosa; Leucadendron coniferum; Leucadendron salicifolium; Leucadendron tinctum; Leucadendron meridianum; Laodelphax striatellus; Sogatella furcifera; Phoxinus eos; Phoxinus rigidus; Phoxinus brevispinosus; Phoxinus bicolor; Tetranychus urticae; Tetranychus turkestani; Tetranychus ludeni; Tetranychus neocaledonicus; Tetranychus amicus; Amphitetranychus viennensis; Eotetranychus rubiphilus; Eotetranychus tiliarium; Oligonychus perseae; Panonychus citri; Bryobia rubrioculus; Schizonobia bundi; Petrobia harti; Xerus princeps; Spermophilus tridecemlineatus and Sciurus carolinensis. © 2009 Blackwell Publishing Ltd.

  2. Monophyly of the species of Hepatozoon (Adeleorina: Hepatozoidae) parasitizing (African) anurans, with the description of three new species from hyperoliid frogs in South Africa.

    Science.gov (United States)

    Netherlands, Edward C; Cook, Courtney A; Du Preez, Louis H; Vanhove, Maarten P M; Brendonck, Luc; Smit, Nico J

    2017-12-04

    Haemogregarines (Apicomplexa: Adeleiorina) are a diverse group of haemoparasites reported from almost all vertebrate classes. The most commonly recorded haemogregarines to parasitize anurans are species of Hepatozoon Miller, 1908. To date 16 Hepatozoon species have been described from anurans in Africa, with only a single species, Hepatozoon hyperolli (Hoare, 1932), infecting a member of the Hyperoliidae. Furthermore, only two Hepatozoon species are known from South African anurans, namely Hepatozoon theileri (Laveran, 1905) and Hepatozoon ixoxo Netherlands, Cook and Smit, 2014, from Amietia delalandii (syn. Amietia quecketti) and three Sclerophrys species, respectively. Blood samples were collected from a total of 225 individuals representing nine hyperoliid species from several localities throughout northern KwaZulu-Natal, South Africa. Twenty frogs from three species were found positive for haemogregarines, namely Afrixalus fornasinii (6/14), Hyperolius argus (2/39), and Hyperolius marmoratus (12/74). Based on morphological characteristics, morphometrics and molecular findings three new haemogregarine species, Hepatozoon involucrum Netherlands, Cook and Smit n. sp., Hepatozoon tenuis Netherlands, Cook and Smit n. sp. and Hepatozoon thori Netherlands, Cook and Smit n. sp., are described from hyperoliid hosts. Furthermore, molecular analyses show anuran Hepatozoon species to be a separate monophyletic group, with species isolated from African hosts forming a monophyletic clade within this cluster.

  3. How aquatic water-beetle larvae with small chambered eyes overcome challenges of hunting under water.

    Science.gov (United States)

    Stowasser, Annette; Buschbeck, Elke K

    2014-11-01

    A particularly unusual visual system exists in the visually guided aquatic predator, the Sunburst Diving Beetle, Thermonectus marmoratus (Coleoptera: Dytiscidae). The question arises: how does this peculiar visual system function? A series of experiments suggests that their principal eyes (E1 and E2) are highly specialized for hunting. These eyes are tubular and have relatively long focal lengths leading to high image magnification. Their retinae are linear, and are divided into distinct green-sensitive distal and UV and polarization-sensitive proximal portions. Each distal retina, moreover, has many tiers of photoreceptors with rhabdomeres the long axis of which are peculiarly oriented perpendicular to the light path. Based on detailed optical investigations, the lenses of these eyes are bifocal and project focused images onto specific retinal tiers. Behavioral experiments suggest that these larvae approach prey within their eyes' near-fields, and that they can correctly gauge prey distances even when conventional distance-vision mechanisms are unavailable. In the near-field of these eyes object distance determines which of the many retinal layers receive the best-focused images. This retinal organization could facilitate an unusual distance-vision mechanism. We here summarize past findings and discuss how these eyes allow Thermonectus larvae to be such successful predators.

  4. Skeletal stiffening in an amphibious fish out of water is a response to increased body weight.

    Science.gov (United States)

    Turko, Andy J; Kültz, Dietmar; Fudge, Douglas; Croll, Roger P; Smith, Frank M; Stoyek, Matthew R; Wright, Patricia A

    2017-10-15

    Terrestrial animals must support their bodies against gravity, while aquatic animals are effectively weightless because of buoyant support from water. Given this evolutionary history of minimal gravitational loading of fishes in water, it has been hypothesized that weight-responsive musculoskeletal systems evolved during the tetrapod invasion of land and are thus absent in fishes. Amphibious fishes, however, experience increased effective weight when out of water - are these fishes responsive to gravitational loading? Contrary to the tetrapod-origin hypothesis, we found that terrestrial acclimation reversibly increased gill arch stiffness (∼60% increase) in the amphibious fish Kryptolebias marmoratus when loaded normally by gravity, but not under simulated microgravity. Quantitative proteomics analysis revealed that this change in mechanical properties occurred via increased abundance of proteins responsible for bone mineralization in other fishes as well as in tetrapods. Type X collagen, associated with endochondral bone growth, increased in abundance almost ninefold after terrestrial acclimation. Collagen isoforms known to promote extracellular matrix cross-linking and cause tissue stiffening, such as types IX and XII collagen, also increased in abundance. Finally, more densely packed collagen fibrils in both gill arches and filaments were observed microscopically in terrestrially acclimated fish. Our results demonstrate that the mechanical properties of the fish musculoskeletal system can be fine-tuned in response to changes in effective body weight using biochemical pathways similar to those in mammals, suggesting that weight sensing is an ancestral vertebrate trait rather than a tetrapod innovation. © 2017. Published by The Company of Biologists Ltd.

  5. Restricted gene flow at the micro- and macro-geographical scale in marble trout based on mtDNA and microsatellite polymorphism

    Directory of Open Access Journals (Sweden)

    Patarnello Tomaso

    2011-04-01

    Full Text Available Abstract Background The genetic structure of the marble trout Salmo trutta marmoratus, an endemic salmonid of northern Italy and the Balkan peninsula, was explored at the macro- and micro-scale level using a combination of mitochondrial DNA (mtDNA and microsatellite data. Results Sequence variation in the mitochondrial control region showed the presence of nonindigenous haplotypes indicative of introgression from brown trout into marble trout. This was confirmed using microsatellite markers, which showed a higher introgression at nuclear level. Microsatellite loci revealed a strong genetic differentiation across the geographical range of marble trout, which suggests restricted gene flow both at the micro-geographic (within rivers and macro-geographic (among river systems scale. A pattern of Isolation-by-Distance was found, in which genetic samples were correlated with hydrographic distances. A general West-to-East partition of the microsatellite polymorphism was observed, which was supported by the geographic distribution of mitochondrial haplotypes. Conclusion While introgression at both mitochondrial and nuclear level is unlikely to result from natural migration and might be the consequence of current restocking practices, the pattern of genetic substructuring found at microsatellites has been likely shaped by historical colonization patterns determined by the geological evolution of the hydrographic networks.

  6. Phylogeographic study of brown trout from Serbia, based on mitochondrial DNA control region analysis

    Directory of Open Access Journals (Sweden)

    Snoj Aleš

    2006-06-01

    Full Text Available Abstract In order to illuminate the phylogeography of brown trout (Salmo trutta populations in the Balkan state of Serbia, the 561 bp 5'-end of mtDNA control region of 101 individuals originating from upland tributaries of the Danubian, Aegean and Adriatic drainages were sequenced and compared to corresponding brown trout sequences obtained in previous studies. Among 15 haplotypes found, 14 were considered native, representing the Danubian and Adriatic lineages of the brown trout, while one haplotype (ATcs1, found only in two individuals originating from two stocked rivers, corresponded to the Atlantic lineage and was considered introduced. Native haplotypes exhibited a strong geographic pattern of distribution: the Danubian haplotypes were strictly confined to the Danubian drainage, while the Adriatic haplotypes dominated in the Aegean and Adriatic drainages; most of the total molecular variance (69% was attributed to differences among the drainages. Phylogenetic reconstruction, supplemented with seven haplotypes newly described in this study, suggested a sister position of the Atlantic-Danubian and Adriatic-Mediterranean-marmoratus ("southern" phylogenetic group, and pointed to the existence of a distinct clade, detected within the "southern" group. The data obtained confirmed our expectation of the existence of high genetic diversity in Balkan trout populations, and we recommend more widespread surveys covering trout stocks from the region.

  7. Determination of steroid hormones in fish tissues by microwave-assisted extraction coupled to ultra-high performance liquid chromatography tandem mass spectrometry.

    Science.gov (United States)

    Guedes-Alonso, Rayco; Sosa-Ferrera, Zoraida; Santana-Rodríguez, José Juan

    2017-12-15

    Steroid hormones produce adverse effects on biota as well as bioaccumulation in fish and seafood, making it necessary to develop methodologies to evaluate these compounds in samples related to the food chain. This work presents an analytical method for evaluating 15 steroid hormones in fish tissue. It is based on microwave-assisted extraction and solid-phase extraction coupled to ultra-high-performance liquid chromatography tandem mass spectrometry (MAE-SPE-UHPLC-MS/MS). The proposed method shows appropriate detection limits (0.14-49.0ngg -1 ), recoveries in the range of 50% and good repeatability. After optimization, the method was applied to different tissues from two small fishes of the Canary Islands that constitute an important level of the food web (Boops boops and Sphoeroides marmoratus) and were exposed to the outfall of the Las Palmas de Gran Canaria wastewater treatment plant. The concentrations of eight detected compounds ranged from below the quantification limits to 3.95μgg -1 . Copyright © 2017 Elsevier Ltd. All rights reserved.

  8. Determining individual variation in growth and its implication for life-history and population processes using the empirical Bayes method.

    Directory of Open Access Journals (Sweden)

    Simone Vincenzi

    2014-09-01

    Full Text Available The differences in demographic and life-history processes between organisms living in the same population have important consequences for ecological and evolutionary dynamics. Modern statistical and computational methods allow the investigation of individual and shared (among homogeneous groups determinants of the observed variation in growth. We use an Empirical Bayes approach to estimate individual and shared variation in somatic growth using a von Bertalanffy growth model with random effects. To illustrate the power and generality of the method, we consider two populations of marble trout Salmo marmoratus living in Slovenian streams, where individually tagged fish have been sampled for more than 15 years. We use year-of-birth cohort, population density during the first year of life, and individual random effects as potential predictors of the von Bertalanffy growth function's parameters k (rate of growth and L∞ (asymptotic size. Our results showed that size ranks were largely maintained throughout marble trout lifetime in both populations. According to the Akaike Information Criterion (AIC, the best models showed different growth patterns for year-of-birth cohorts as well as the existence of substantial individual variation in growth trajectories after accounting for the cohort effect. For both populations, models including density during the first year of life showed that growth tended to decrease with increasing population density early in life. Model validation showed that predictions of individual growth trajectories using the random-effects model were more accurate than predictions based on mean size-at-age of fish.

  9. Ready for a fight? The physiological effects of detecting an opponent's pheromone cues prior to a contest.

    Science.gov (United States)

    Garcia, Mark J; Williams, John; Sinderman, Benjamin; Earley, Ryan L

    2015-10-01

    Reception of pheromone cues can elicit significant physiological (e.g. steroid hormone levels) changes in the recipient. These pheromone-induced physiological changes have been well documented for male-female interactions, but scarcely in same-sex interactions (male-male and female-female). We sought to address this dearth in the current literature and examine whether mangrove rivulus fish (Kryptolebias marmoratus) could detect and, ultimately, mount a physiological response to the pheromone signature of a potential, same-sex competitor. We examined steroid hormone levels in mangrove rivulus exposed to one of three treatments: 1) isolation, 2) exposure to pheromones of a size-matched partner, and 3) pheromone exposure to a size-matched opponent followed by a physical encounter with the opponent. We found that exposure to a competitor's pheromone cues elicited a significant increase in testosterone levels. Increases in testosterone were similar across genetically distinct lineages derived from geographically distinct populations. Further, testosterone levels were similar between individuals only exposed to pheromone cues and individuals exposed to both pheromone cues and a subsequent physical encounter. Our findings led us to generate a number of testable predictions regarding how mangrove rivulus utilize pheromone signals in social interactions, the molecular mechanisms linking social stimuli and hormonal responses, and the possible adaptive benefits of hormonal responsiveness to receiving a potential competitor's pheromone cues. Copyright © 2015 Elsevier Inc. All rights reserved.

  10. Deciphering the social structure of Marbled Murrelets from behavioral observations at sea

    Science.gov (United States)

    Speckman, Suzann G.; Piatt, John F.; Springer, Alan M.

    2003-01-01

    We surveyed Marbled Murrelets (Brachyramphus marmoratus) daily from small boats in Auke Bay and Fritz Cove, Alaska, from May through August 1992 and 1993. Differences in numbers of juveniles and in the timing of their presence in the study area between the two years indicated that breeding phenology was late and productivity was low in 1992 compared to 1993. This difference was consistent with variability in the physical environment. Of 99 fish identified in the bills of fish-holding adult murrelets, 81 (82%) were Pacific Sand Lance (Ammodytes hexapterus). Counts of fish-holding adult murrelets were significantly higher in the evening than at any other time of day. Time of day had no significant effects on counts of fledglings, indicating that juveniles were moving into and out of the study area during the day. Murrelets were predominantly found in groups of two or more, even during incubation, suggesting that murrelets incur an appreciable benefit, such as increased foraging efficiency, from foraging in groups. For both summers, there was no correlation between counts of murrelets on the water and numbers of murrelet detections in the adjacent forest. We suggest that many behavior patterns of the Marbled Murrelet (displaying, choosing of mates, and pair-bonding, finding of nest sites and successful foraging of juveniles) may be socially facilitated.

  11. Determining individual variation in growth and its implication for life-history and population processes using the empirical Bayes method.

    Science.gov (United States)

    Vincenzi, Simone; Mangel, Marc; Crivelli, Alain J; Munch, Stephan; Skaug, Hans J

    2014-09-01

    The differences in demographic and life-history processes between organisms living in the same population have important consequences for ecological and evolutionary dynamics. Modern statistical and computational methods allow the investigation of individual and shared (among homogeneous groups) determinants of the observed variation in growth. We use an Empirical Bayes approach to estimate individual and shared variation in somatic growth using a von Bertalanffy growth model with random effects. To illustrate the power and generality of the method, we consider two populations of marble trout Salmo marmoratus living in Slovenian streams, where individually tagged fish have been sampled for more than 15 years. We use year-of-birth cohort, population density during the first year of life, and individual random effects as potential predictors of the von Bertalanffy growth function's parameters k (rate of growth) and L∞ (asymptotic size). Our results showed that size ranks were largely maintained throughout marble trout lifetime in both populations. According to the Akaike Information Criterion (AIC), the best models showed different growth patterns for year-of-birth cohorts as well as the existence of substantial individual variation in growth trajectories after accounting for the cohort effect. For both populations, models including density during the first year of life showed that growth tended to decrease with increasing population density early in life. Model validation showed that predictions of individual growth trajectories using the random-effects model were more accurate than predictions based on mean size-at-age of fish.

  12. In Vitro and in Vivo Anticancer Activity of Pardaxin against Proliferation and Growth of Oral Squamous Cell Carcinoma

    Directory of Open Access Journals (Sweden)

    Yifan Han

    2015-12-01

    Full Text Available Pardaxin (H-GFFALIPKIISSPLFKTLLSAVGSALSSSGGQE-OH, a 33-amino-acid polypeptide, is an antimicrobial peptide (AMP isolated from the marine fish species Pardachirus marmoratus. Pardaxin shows antibacterial and antitumor activities. However, pardaxin-induced inhibition of oral cancer and the mechanism of tumor reduction in buccal pouch carcinogenesis after pardaxin painting remain undetermined. Additionally, the toxic effects of pardaxin on normal tissue remain unclear. The present study investigated the anticancer activity of pardaxin in oral squamous cell carcinoma (OSCC cells in the hamster buccal pouch model with or without 7,12-dimethylbenz[a]anthracene (DMBA pretreatment. This is the first study to confirm the effects of pardaxin on normal tissue and its nontoxic effects in vivo. Cell viability assays and colony formation tests in OSCC cell lines (SCC-4 demonstrated that pardaxin reduced cell viability in a dose-dependent manner. Immunofluorescence staining of cleaved caspase-3 in SCC-4 cells revealed that expression of activated caspase-3 in SCC-4 cells significantly increased after 24-h treatment with pardaxin. Additionally, a cell cycle analysis indicated that pardaxin treatment resulted in the cell cycle arrest of SCC-4 cells in the G2/M phase, thereby limiting cell proliferation. Furthermore, pardaxin treatment substantially alleviated carcinogenesis in the DMBA-induced hamster buccal pouch model by lowering prostaglandin E2 levels. These results suggest that pardaxin is a potential marine drug for adjuvant chemotherapy for human OSCC and oral cancer.

  13. Eficacia del control de larvas de vectores de la malaria con peces larvívoros nativos en San Martín, Perú

    Directory of Open Access Journals (Sweden)

    Elmer Rojas P

    2004-01-01

    Full Text Available Objetivo: Determinar la eficacia del control larvario de vectores de la malaria con peces larvívoros nativos en San Martín, Perú. Material y métodos: Estudio experimental que se llevó a cabo en las localidades de Yumbatos, Alianza y San Juan de Shanusi con ocho criaderos cada uno, identificándose las especies nativas Rivulus urophtalmus "chuina" y Pyrrulina brevis "achualillo" comparados con la eficacia ejercida por Poecilia reticulata "guppy". Se midieron variables como temperatura, pH, concentración de electrolitos en el agua, densidad de los peces y presencia de otros depredadores. Resultados: Los peces nativos alcanzaron una eficacia de 98% en el control de larvas de Anopheles, cuando se mantuvieron en densidades entre 10 y 15 peces/m²; estos peces alcanzan longitudes hasta de 8 cm, y tienen similar o mayor voracidad que Poecilia reticulata. Asimismo, se evidenció la existencia de peces depredadores, Hoplias malabaricus "fasaco" y Simbranchus marmoratus "atinga", los que se alimentan de estos peces pequeños. Conclusiones: Los peces nativos son eficaces para el control de larvas de Anopheles; asimismo, se deben tener en cuenta la existencia de otras especies depredadoras, así como la limpieza de la maleza de los criaderos para incrementar la eficacia del control.

  14. Taxonomic revision of the South American catfish genus Ageneiosus (Siluriformes: Auchenipteridae) with the description of four new species

    Science.gov (United States)

    Ribeiro, Frank R.V.; Rapp Py-Daniel, Lúcia H.; Walsh, Stephen J.

    2017-01-01

    The catfish genus Ageneiosus in the exclusively Neotropical family Auchenipteridae is revised. Species of Ageneiosus are widely distributed in all major South American continental drainages except the São Francisco River basin and small rivers along the Brazilian east coast. The taxonomic revision was based on examination of available type specimens, additional museum material and comparisons of original descriptions. A suite of morphometric, meristic and qualitative characters of internal and external anatomy were used to diagnose valid species and determine synonyms. Thirteen valid species are recognized in the genus Ageneiosus, some of which are widely distributed across South America. Ageneiosus pardalis is the only trans-Andean species in the genus. Ageneiosus polystictus and Ageneiosus uranophthalmus are more widely distributed than previously reported. Ageneiosus marmoratus is a junior synonym of Ageneiosus inermis. Ageneiosus dentatus is a valid species and its name is removed from the synonymy of Ageneiosus ucayalensis. Four new species are described: Ageneiosus akamai, Ageneiosus apiaka, Ageneiosus intrusus and Ageneiosus lineatus, all from the Amazon River basin. A dichotomous key for all 13 valid species of Ageneiosus species is provided.

  15. Fish fauna from Gârla Pasărea, a heavy modified former floodplain watercourse

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    NĂVODARU Ion

    2008-10-01

    Full Text Available The “Gârla Pasarea” was a former flood plane watercourse in connection with Vedea River discharged in Danube River. The floodplane was embanked for agriculture polder, Vedea River was redirected to discharge direct into Danube River and Gârla Pasarea was cut in several sectors, connected through underground tubes. Fish fauna inventory of Gârla Pasarea was performed in august 2007, using for shallow water backpack electrofisher and deep large water by Nordic gillnets. The species richness includes 15 fish species with a gradient of increasing from upstream to downstream. The most frequent species (very abundant are two exotic respectively, Pseudorasbora parva and Carassius gibelio that survive in extreme condition. Four species are included in Annexes of Emergency Order of Romanian Govern No.57/2007, concerning regime of natural protected area,conservation of natural habitats and wild flora and fauna, respectively Aspius aspius, Cobitis danubialis (elangoides and Misgurnus fossilis are included in Annex 3 that need designate of Special Protected Area for conservation (SPA, andProterorhinus marmoratus (semilunaris is included in Annex 4B, for species of national interest that need strict protection. Recovering and conservation of fish fauna need ecological restoration based on rebuilding of longitudinal connectivity of Gârla Pasarea sectors, reconnect with Vedea River and lateral connectivity of Danube River with it former floodplane.

  16. Bmp suppression in mangrove killifish embryos causes a split in the body axis.

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    Sulayman Mourabit

    Full Text Available Bone morphogenetic proteins (Bmp are major players in the formation of the vertebrate body plan due to their crucial role in patterning of the dorsal-ventral (DV axis. Despite the highly conserved nature of Bmp signalling in vertebrates, the consequences of changing this pathway can be species-specific. Here, we report that Bmp plays an important role in epiboly, yolk syncytial layer (YSL movements, and anterior-posterior (AP axis formation in embryos of the self-fertilizing mangrove killifish, Kryptolebias marmoratus. Stage and dose specific exposures of embryos to the Bmp inhibitor dorsomorphin (DM produced three distinctive morphologies, with the most extreme condition creating the splitbody phenotype, characterised by an extremely short AP axis where the neural tube, somites, and notochord were bilaterally split. In addition, parts of caudal neural tissues were separated from the main body and formed cell islands in the posterior region of the embryo. This splitbody phenotype, which has not been reported in other animals, shows that modification of Bmp may lead to significantly different consequences during development in other vertebrate species.

  17. Artificial barriers prevent genetic recovery of small isolated populations of a low-mobility freshwater fish.

    Science.gov (United States)

    Coleman, R A; Gauffre, B; Pavlova, A; Beheregaray, L B; Kearns, J; Lyon, J; Sasaki, M; Leblois, R; Sgro, C; Sunnucks, P

    2018-01-12

    Habitat loss and fragmentation often result in small, isolated populations vulnerable to environmental disturbance and loss of genetic diversity. Low genetic diversity can increase extinction risk of small populations by elevating inbreeding and inbreeding depression, and reducing adaptive potential. Due to their linear nature and extensive use by humans, freshwater ecosystems are especially vulnerable to habitat loss and fragmentation. Although the effects of fragmentation on genetic structure have been extensively studied in migratory fishes, they are less understood in low-mobility species. We estimated impacts of instream barriers on genetic structure and diversity of the low-mobility river blackfish (Gadopsis marmoratus) within five streams separated by weirs or dams constructed 45-120 years ago. We found evidence of small-scale (barriers, as expected for a fish with low mobility. Genetic diversity was lower above barriers in small streams only, regardless of barrier age. In particular, one isolated population showed evidence of a recent bottleneck and inbreeding. Differentiation above and below the barrier (F ST  = 0.13) was greatest in this stream, but in other streams did not differ from background levels. Spatially explicit simulations suggest that short-term barrier effects would not be detected with our data set unless effective population sizes were very small (barriers is reduced and requires more genetic markers compared to panmictic populations. We also demonstrate the importance of accounting for natural population genetic structure in fragmentation studies.

  18. Toxin gene determination and evolution in scorpaenoid fish.

    Science.gov (United States)

    Chuang, Po-Shun; Shiao, Jen-Chieh

    2014-09-01

    In this study, we determine the toxin genes from both cDNA and genomic DNA of four scorpaenoid fish and reconstruct their evolutionary relationship. The deduced protein sequences of the two toxin subunits in Sebastapistes strongia, Scorpaenopsis oxycephala, and Sebastiscus marmoratus are about 700 amino acid, similar to the sizes of the stonefish (Synanceia horrida, and Synanceia verrucosa) and lionfish (Pterois antennata and Pterois volitans) toxins previously published. The intron positions are highly conserved among these species, which indicate the applicability of gene finding by using genomic DNA template. The phylogenetic analysis shows that the two toxin subunits were duplicated prior to the speciation of Scorpaenoidei. The precedence of the gene duplication over speciation indicates that the toxin genes may be common to the whole family of Scorpaeniform. Furthermore, one additional toxin gene has been determined in the genomic DNA of Dendrochirus zebra. The phylogenetic analysis suggests that an additional gene duplication occurred before the speciation of the lionfish (Pteroinae) and a pseudogene may be generally present in the lineage of lionfish. Copyright © 2014 Elsevier Ltd. All rights reserved.

  19. Modeling habitat for Marbled Murrelets on the Siuslaw National Forest, Oregon, using lidar data

    Science.gov (United States)

    Hagar, Joan C.; Aragon, Ramiro; Haggerty, Patricia; Hollenbeck, Jeff P.

    2018-03-28

    Habitat models using lidar-derived variables that quantify fine-scale variation in vegetation structure can improve the accuracy of occupancy estimates for canopy-dwelling species over models that use variables derived from other remote sensing techniques. However, the ability of models developed at such a fine spatial scale to maintain accuracy at regional or larger spatial scales has not been tested. We tested the transferability of a lidar-based habitat model for the threatened Marbled Murrelet (Brachyramphus marmoratus) between two management districts within a larger regional conservation zone in coastal western Oregon. We compared the performance of the transferred model against models developed with data from the application location. The transferred model had good discrimination (AUC = 0.73) at the application location, and model performance was further improved by fitting the original model with coefficients from the application location dataset (AUC = 0.79). However, the model selection procedure indicated that neither of these transferred models were considered competitive with a model trained on local data. The new model trained on data from the application location resulted in the selection of a slightly different set of lidar metrics from the original model, but both transferred and locally trained models consistently indicated positive relationships between the probability of occupancy and lidar measures of canopy structural complexity. We conclude that while the locally trained model had superior performance for local application, the transferred model could reasonably be applied to the entire conservation zone.

  20. A Study of lymphangiogenesis in a gecko model of tail autotomy

    International Nuclear Information System (INIS)

    Tsopelas, C.; Munns, S.L.; Lewis, B.; Daniels, C.B.; Cooter, R.D.; Chatterton, B.E.

    2002-01-01

    Full text: Lymphoedema is a debilitating problem for which there is no effective cure. Lymphatic vessels do not regenerate after injuries such as infection, trauma, radiotherapy or tumour invasion. One approach is to determine whether lymph vessels can be regenerated in tissues where these structures have been damaged or removed. This study examined lymphangiogenesis in a gecko model of tail autotomy. Christinus marmoratus can regenerate its tail which is non-oedematous. The lymphatics of gecko tails were visualised using 99m Tc-Sb 2 S 3 colloid, image analyses provided lymph speed and % activity migrated from the injection site. Histological images yielded density and diameter of lymphatic vessels. Measurements were obtained for geckos with non-regenerate tails, 3,6, 9,12, 15, 18 and >24 week (fully) old regenerated tails post autotomy (pa). Fully regenerated tails had significantly slower lymph speed, slower radiocolloid migration from injection site, lower lymphatic density and higher diameter of lymphatic vessels, than similar sized geckos with non-regenerate tails. Their comparison to 6-18 week old tails, confirmed no significant difference in lymph speed, radiocolloid migration or diameter of lymphatic vessels. No measurable lymphatic flow was seen at 3 weeks pa. A functional lymphatic network was established in regenerating gecko tails, where a combination of data elude to a critical lymphangiogenesis period during 3-6 weeks post autotomy. Copyright (2002) The Australian and New Zealand Society of Nuclear Medicine Inc

  1. Marbled Murrelets Select Distinctive Nest Trees within Old-Growth Forest Patches

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    Michael P. Silvergieter

    2011-12-01

    Full Text Available The coastal old-growth forests of North America's Pacific Coast are renowned both for their commercial and ecological value. This study adds to growing evidence that selective harvesting of the largest trees may have a disproportionate ecological impact. Marbled Murrelets (Brachyramphus marmoratus, a threatened species, nest almost exclusively in these old-growth forests. Detailed knowledge of nesting habitat selection provides guidance for habitat management and conservation. Habitat selection for this species has been studied at a variety of scales using ground and remote methods. However, because Marbled Murrelet nesting activity is limited to a single mossy platform on a single tree, we investigated nest tree selection within old-growth forest patches, using a set of 59 forest patches containing active nests. Nest trees were usually distinctive compared with neighboring trees in the surrounding 25 m radius patch. They averaged 15 to 20% taller than neighboring trees depending on region, had significantly larger stem diameters, more potential nesting platforms, and more moss. They had the most extreme values of height and width about three times as often as expected by chance. An analysis of moss platform use as a function of number of platforms per platform tree suggests that murrelets select individual platforms, rather than platform trees per se. Nonetheless, highly selective logging practices that remove high-value trees from stands may also remove trees most likely to be selected by nesting murrelets.

  2. Gyrodactylus salinae n. sp. (Platyhelminthes: Monogenea infecting the south European toothcarp Aphanius fasciatus (Valenciennes (Teleostei, Cyprinodontidae from a hypersaline environment in Italy

    Directory of Open Access Journals (Sweden)

    Huyse Tine

    2011-06-01

    Full Text Available Abstract Background Historically, non-native species of Gambusia (Poeciliidae have been used to control larval stages of the Asian tiger mosquito, Stegomyia albopicta Reinert, Harbach et Kitching, 2004 throughout Italy. The potential utility of indigenous populations of Aphanius fasciatus (Valenciennes (Teleostei: Cyprinodontidae as an appropriate alternative biological control is currently being explored. A sub-sample of ten fish collected from Cervia Saline, Italy (salinity 65 ppt; 30°C to assess their reproductive capability in captivity, harboured a moderate infection of Gyrodactylus von Nordmann, 1832 (Platyhelminthes, Monogenea. A subsequent morphological and molecular study identified this as being a new species. Results Gyrodactylus salinae n. sp. is described from the skin, fins and gills of A. fasciatus. Light and scanning electron microscopical (SEM examination of the opisthaptoral armature and their comparison with all other recorded species suggested morphological similarities to Gyrodactylus rugiensoides Huyse et Volckaert, 2002 from Pomatoschistus minutus (Pallas. Features of the ventral bar, however, permit its discrimination from G. rugiensoides. Sequencing of the nuclear ribosomal DNA internal transcribed spacers 1 and 2 and the 5.8S rRNA gene and a comparison with all species listed in GenBank confirmed they are unique and represent a new species (most similar to Gyrodactylus anguillae Ergens, 1960, 8.3% pair-wise distance based on 5.8S+ITS2. This represents the first species of Gyrodactylus to be described from Aphanius and, to date, has the longest ITS1 (774 bp sequenced from any Gyrodactylus. Additional sampling of Cervia Saline throughout the year, found G. salinae n. sp. to persist in conditions ranging from 35 ppt and 5°C in December to 65 ppt and 30°C in July, while in captivity a low level of infection was present, even in freshwater conditions (0 ppt. Conclusions The ability of G. salinae n. sp. to tolerate a wide

  3. The Hei River Basin in northwestern China - tectonics, sedimentary processes and pathways

    Science.gov (United States)

    Rudersdorf, Andreas; Nottebaum, Veit; Schimpf, Stefan; Yu, Kaifeng; Hartmann, Kai; Stauch, Georg; Wünnemann, Bernd; Reicherter, Klaus; Diekmann, Bernhard; Lehmkuhl, Frank

    2014-05-01

    The Hei River Basin (catchment area of c. 130,000 km²) is situated at the transition between the northern margin of the Tibetan Plateau and the southern slopes of Gobi-Tien-Shan. As part of the northwestern Chinese deserts, the Ejina Basin (Gaxun Nur Basin) constitutes the endorheic erosion base of the drainage system. The basin - hosting the second largest continental alluvial fans in the world, is tectonically strongly shaped by the Gobi belt of left-lateral transpression. The tectonic setting in combination with competing climatic driving forces (Westerlies and summer/winter monsoon currents) has supported the formation of a valuable long-time sediment archive comprises at least the last 250,000 yrs. of deposition. It is composed by the interplay of eolian, fluvial and lacustrine sedimentation cycles and today is dominated by widespread (gravel) gobi surfaces, insular dune fields and shallow evaporitic playa areas. Thus, it provides excellent conditions to investigate tectonic evolution and Quaternary environmental changes. Recently, geomorphological, geophysical, neotectonic and mineralogical studies have enhanced the understanding of the environmental history and the modern depositional environment. Moreover, the role of the Hei River Basin as an important source area of silt particles which were later deposited on the Chinese Loess Plateau is evaluated. Therefore, a 230 m long drill core, sediment sections and ca. 700 surface samples throughout the whole catchment and basin were analyzed. Instrumental and historical seismicity are very low, but the proximity to active fault zones and dating irregularities in earlier publications indicate evidence for deformation in the study area. Despite flat topography, indications of active tectonics such as fault-related large-scale lineations can be observed. Seismically deformed unconsolidated lacustrine deposits (seismites), presumably of Holocene age, are evident and must be related to the nearby faults. The upper

  4. Disturbance of a rare seabird by ship-based tourism in a marine protected area

    Science.gov (United States)

    Marcella, Timothy K.; Gende, Scott M.; Roby, Daniel D.; Allignol, Arthur

    2017-01-01

    Managers of marine protected areas (MPAs) must often seek ways to allow for visitation while minimizing impacts to the resources they are intended to protect. Using shipboard observers, we quantified the “zone of disturbance” for Kittlitz’s and marbled murrelets (Brachyramphus brevirostris and B. marmoratus) exposed to large cruise ships traveling through Glacier Bay National Park, one of the largest MPAs in North America. In the upper reaches of Glacier Bay, where Kittlitz’s murrelets predominated, binary logistic regression models predicted that 61% of all murrelets within 850 m perpendicular distance of a cruise ship were disturbed (defined as flushing or diving), whereas in the lower reaches, where marbled murrelets predominated, this percentage increased to 72%. Using survival analysis, murrelets in both reaches were found to react at greater distances when ships approached indirectly, presumably because of the ship’s larger profile, suggesting murrelets responded to visual rather than audio cues. No management-relevant covariates (e.g., ship velocity, route distance from shore) were found to be important predictors of disturbance, as distance from ship to murrelet accounted for > 90% of the explained variation in murrelet response. Utilizing previously published murrelet density estimates from Glacier Bay, and applying an average empirical disturbance probability (68%) out to 850 m from a cruise ship’s typical route, we estimated that a minimum of 9.8–19.6% of all murrelets in Glacier Bay are disturbed per ship entry. Whether these disturbance levels are inconsistent with Park management objectives, which include conserving wildlife as well as providing opportunities for visitation, depends in large part on whether disturbance events caused by cruise ships have impacts on murrelet fitness, which remains uncertain.

  5. Natural Distribution of Parasitoids of Larvae of the Fall Armyworm, Spodoptera frugiperda, in Argentina

    Science.gov (United States)

    Gabriela Murúa, M.; Molina-Ochoa, Jaime; Fidalgo, Patricio

    2009-01-01

    To develop a better understanding of the natural distribution of the fall armyworm, Spodoptera frugiperda (Smith) (Lepidoptera: Noctuidae), and to update the knowledge of the incidence of its complex of parasitoids. S. frugiperda, samplings in whorl-stage corn were carried out in provinces of Argentina from 1999 to 2003. S. frugiperda larvae were collected from corn in localities of the provinces of Tucumán, Salta, Jujuy, Santiago del Estero, La Rioja, Córdoba, San Luis, Chaco and Misiones. In each locality 30 corn plants were sampled and only larvae located in those plants were collected. The parasitoids that emerged from S. frugiperda larvae were identified and counted. The abundance of the parasitoids and the parasitism rate were estimated. The S. frugiperda parasitoids collected were Campoletis grioti (Blanchard) (Hymenoptera: Ichneumonidae), Chelonus insularis (Cresson) (Hymenoptera: Braconidae), Archytas marmoratus (Townsend) (Diptera Tachinidae) and/or A. incertus (Macquart), Ophion sp. (Hymenoptera: Ichneumonidae), Euplectrus platyhypenae Howard (Hymenoptera: Eulophidae), and Incamyia chilensis (Aldrich) (Diptera Tachinidae). C. grioti was the most abundant and frequent during the five-year survey. Similar diversity of parasitoids was obtained in all the provinces, with the exception of I. chilensis and E. platyhypenae that were recovered only in the province of Salta. In the Northwestern region, in Tucumán, C. grioti and species of Archytas were the most abundant and frequent parasitoids. On the contrary, in Salta and Jujuy Ch. insularis was the parasitoid most abundant and frequently recovered. The parasitism rate obtained in Tucumán, Salta and Jujuy provinces were 21.96%, 17.87% and 6.63% respectively with an average of 18.93%. These results demonstrate that hymenopteran and dipteran parasitoids of S. frugiperda occurred differentially throughout the Argentinian provinces and played an important role on the natural control of the S. frugiperda larval

  6. MR findings of cerebral palsy: comparison between preterm patients and fullterm patients

    Energy Technology Data Exchange (ETDEWEB)

    Hwang, Yoon Joon; Kim, Dong Ik; Yoon, Pyeong Ho; Jeon, Pyoung; Ryu, Young Hoon; Hwang, Geum Ju; Kim, Eun Kyung [Yonsei Univ. College of Medicine, Seoul (Korea, Republic of); Lee, Byung Hee [Pundang Cha General Hospital, Sungnam (Korea, Republic of)

    1997-09-01

    To observe the MR findings of cerebral palsy by evaluating cerebral damage resulting from hypoxic ischemic injury and other variable causes and to compare the findings between preterm and full-term patients. We reviewed the MR findings of 102 cerebral palsy patients (71 full-term and 31 preterm). These were analysed with regard to deep and peripheral white matter, gray matter, basal ganglia, the thalamus, brainstem, cerebellum, corpus callosum and ventricles, according to the pattern of injury such as hypoxic ischemic injury, migration anomaly and early intrauterine injury, the findings of full-term and preterm patients were then compared. MR findings of preterm patients(n=3D31) were as follows;hypoxic ischemic injury(n=3D26),normal(n=3D2), and migration anomaly(n=3D3), while those of full-term patients(n=3D71) were hypoxic ischemic injury(n=3D41), normal(n=3D24), migration anomaly(n=3D4), early uterine injury(n=3D2), and perirolandic ischemic injury(n=3D6);in 5 patients, this latter condition was combined with status marmoratus. Periventricular leukomalacia was the most common finding in both preterm patients and full-term patients;selective neuronal necrosis, parasagittal injury and perirolandic injury were observed only in full-term patients. On MRI, variable findings of cerebral palsy were clearly observed;periventricular leukomalacia was the most common finding in both preterm and full-term patients.=20.

  7. MR findings of cerebral palsy: comparison between preterm patients and fullterm patients

    International Nuclear Information System (INIS)

    Hwang, Yoon Joon; Kim, Dong Ik; Yoon, Pyeong Ho; Jeon, Pyoung; Ryu, Young Hoon; Hwang, Geum Ju; Kim, Eun Kyung; Lee, Byung Hee

    1997-01-01

    To observe the MR findings of cerebral palsy by evaluating cerebral damage resulting from hypoxic ischemic injury and other variable causes and to compare the findings between preterm and full-term patients. We reviewed the MR findings of 102 cerebral palsy patients (71 full-term and 31 preterm). These were analysed with regard to deep and peripheral white matter, gray matter, basal ganglia, the thalamus, brainstem, cerebellum, corpus callosum and ventricles, according to the pattern of injury such as hypoxic ischemic injury, migration anomaly and early intrauterine injury, the findings of full-term and preterm patients were then compared. MR findings of preterm patients(n=3D31) were as follows;hypoxic ischemic injury(n=3D26),normal(n=3D2), and migration anomaly(n=3D3), while those of full-term patients(n=3D71) were hypoxic ischemic injury(n=3D41), normal(n=3D24), migration anomaly(n=3D4), early uterine injury(n=3D2), and perirolandic ischemic injury(n=3D6);in 5 patients, this latter condition was combined with status marmoratus. Periventricular leukomalacia was the most common finding in both preterm patients and full-term patients;selective neuronal necrosis, parasagittal injury and perirolandic injury were observed only in full-term patients. On MRI, variable findings of cerebral palsy were clearly observed;periventricular leukomalacia was the most common finding in both preterm and full-term patients.=20

  8. Comparison of pigment cell ultrastructure and organisation in the dermis of marble trout and brown trout, and first description of erythrophore ultrastructure in salmonids.

    Science.gov (United States)

    Djurdjevič, Ida; Kreft, Mateja Erdani; Sušnik Bajec, Simona

    2015-11-01

    Skin pigmentation in animals is an important trait with many functions. The present study focused on two closely related salmonid species, marble trout (Salmo marmoratus) and brown trout (S. trutta), which display an uncommon labyrinthine (marble-like) and spot skin pattern, respectively. To determine the role of chromatophore type in the different formation of skin pigment patterns in the two species, the distribution and ultrastructure of chromatophores was examined with light microscopy and transmission electron microscopy. The presence of three types of chromatophores in trout skin was confirmed: melanophores; xanthophores; and iridophores. In addition, using correlative microscopy, erythrophore ultrastructure in salmonids was described for the first time. Two types of erythrophores are distinguished, both located exclusively in the skin of brown trout: type 1 in black spot skin sections similar to xanthophores; and type 2 with a unique ultrastructure, located only in red spot skin sections. Morphologically, the difference between the light and dark pigmentation of trout skin depends primarily on the position and density of melanophores, in the dark region covering other chromatophores, and in the light region with the iridophores and xanthophores usually exposed. With larger amounts of melanophores, absence of xanthophores and presence of erythrophores type 1 and type L iridophores in the black spot compared with the light regions and the presence of erythrophores type 2 in the red spot, a higher level of pigment cell organisation in the skin of brown trout compared with that of marble trout was demonstrated. Even though the skin regions with chromatophores were well defined, not all the chromatophores were in direct contact, either homophilically or heterophilically, with each other. In addition to short-range interactions, an important role of the cellular environment and long-range interactions between chromatophores in promoting adult pigment pattern

  9. New Mediterranean Biodiversity Records (April 2015

    Directory of Open Access Journals (Sweden)

    Α. ΖΕΝΕΤΟΣ

    2015-01-01

    Full Text Available The Collective Article ‘New Mediterranean Biodiversity Records’ of the Mediterranean Marine Science journal offers the means to publish biodiversity records in the Mediterranean Sea. The current article is divided in two parts, for records of native and alien species respectively. The new records of native fish species include: the slender sunfish Ranzania laevis and the scalloped ribbonfish Zu cristatus in Calabria; the Azores rockling Gaidropsarus granti in Calabria and Sicily; the agujon needlefish Tylosurus acus imperialis in the Northern Aegean; and the amphibious behaviour of Gouania willdenowi in Southern Turkey. As regards molluscs, the interesting findings include Ischnochiton usticensis in Calabria and Thordisa filix in the bay of Piran (Slovenia. The stomatopod Parasquilla ferussaci was collected from Lesvos island (Greece; the isopod Anilocra frontalis was observed parasitizing the alien Pteragogus trispilus in the Rhodes area. The asteroid Tethyaster subinermis and the butterfly ray Gymnura altavela were reported from several localities in the Greek Ionian and Aegean Seas. The new records of alien species include: the antenna codlet Bregmaceros atlanticus in Saronikos Gulf; three  new fish records and two decapods from Egypt; the establishment of the two spot cardinal fish Cheilodipterus novemstriatus and the first record of the Indo-Pacific marble shrimp Saron marmoratus in semi-dark caves along the Lebanese coastline; the finding of Lagocephalus sceleratus, Sargocentron rubrum, Fistularia commersonii and Stephanolepis diaspros around Lipsi island (Aegean Sea, Greece; the decapod Penaeus hathor in Aegean waters; the decapod Penaeus aztecus and the nudibranch Melibe viridis in the Dodecanese islands; the finding of Pinctada imbricata radiata in the Mar Grande of Taranto (Ionian Sea, Italy and the Maliakos Gulf (Greece.

  10. Ecological and human exposure assessment to PBDEs in Adige River.

    Science.gov (United States)

    Giulivo, Monica; Suciu, Nicoleta Alina; Eljarrat, Ethel; Gatti, Marina; Capri, Ettore; Barcelo, Damia

    2018-07-01

    The interest for environmental issues and the concern resulting from the potential exposure to contaminants were the starting point to develop methodologies in order to evaluate the consequences that those might have over both the environment and human health. Considering the feature of POPs, including PBDEs, such as bioaccumulation, biomagnification, long-range transport and adverse effects even long time after exposure, risk assessment of POPs requires specific approaches and tools. In this particular context, the MERLIN-Expo tool was used to assess the aquatic environmental exposure of Adige River to PBDEs and the accumulation of PBDEs in humans through the consumption of possible contaminated local aquatic food. The aquatic food web models provided as output of the deterministic simulation the time trend of concentrations for twenty years of BDE-47 and total PBDEs, expressed using the physico-chemical properties of BDE-47, in aquatic organisms of the food web of Adige River. For BDE-47, the highest accumulated concentrations were detected for two benthic species: Thymallus thymallus and Squalius cephalus whereas the lowest concentrations were obtained for the pelagic specie Salmo trutta marmoratus. The trend obtained for the total PBDEs, calculated using the physico-chemical properties of BDE-47, follows the one of BDE-47. For human exposure, different BDE-47 and total PBDEs concentration trends between children, adolescent, adults and elderly were observed, probably correlated with the human intake of fish products in the daily diet and the ability to metabolize these contaminants. In detail, for the adolescents, adults and elderly a continuous accumulation of the target contaminants during the simulation's years was observed, whereas for children a plateau at the end of the simulation period was perceived. Copyright © 2018 Elsevier Inc. All rights reserved.

  11. Systematic review and cladistic analysis of the Hernandariinae (Opiliones: Gonyleptidae

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    Marcio Bernardino DaSilva

    2010-08-01

    Full Text Available The harvestmen subfamily Hernandariinae is reviewed and a new classification is proposed based on cladistic analysis using 67 morphological characters. The subfamily is composed of six genera and 23 species and occurs in south-southeastern Brazil, Paraguay, and northeastern Argentina. Fourteen new combinations are proposed: Hernandaria armatifrons (Roewer, 1917; H. una (Mello-Leitão, 1927; Acrogonyleptes granulatus (H. Soares, 1966; A. pectinifemur (Soares & Soares, 1947; Acanthogonyleptes alticola (Mello-Leitão, 1922; A. editus (Roewer, 1943; A. fallax (Mello-Leitão, 1932; A. fulvigranulatus (Mello-Leitão, 1922; A. marmoratus (Mello-Leitão, 1940; A. pictus (Piza, 1942; A. singularis (Mello-Leitão, 1935; A. soaresi (Mello-Leitão, 1944; A. variolosus (Mello-Leitão, 1944. Seven synonymies are proposed: Proweyhia Mello-Leitão, 1927 and Metaxundarava Mello-Leitão, 1927 = Hernandaria Sørensen, 1884; Apembolephaenus calcaratus Soares & Soares, 1945 = H. armatifrons (Roewer, 1917; Sphaerobunus Rower, 1917 and Paraproweyhia Soares & Soares, 1947 = Acrogonyleptes Roewer, 1917; Paraproweyhia curitibae Soares & Soares, 1947 = Acrogonyleptes exochus (Mello-Leitão, 1931; and Melloleitaniana curitibae B. Soares, 1943 = Acrogonyleptes spinifrons Roewer, 1917. Three species are revalidated: Acrogonyleptes granulatus (H. Soares, 1966, A. pectinifemur (Soares & Soares, 1947, and A. spinifrons Roewer, 1917. Seven new species are described: Hernandaria sundermannorum sp. nov. (São Paulo State, Brazil, Hernandaria anitagaribaldiae sp. nov. (Santa Catarina State, Brazil, Hernandaria zumbii sp. nov. (Santa Catarina State, Brazil, Hernandaria chicomendesi sp. nov. (Santa Catarina State, Brazil, Acrogonyleptes cheguevarai sp. nov. (Rio Grande do Sul State, Brazil, Pseudotrogulus pagu sp. nov. (São Paulo State, Brazil, Pseudotrogulus trotskyi sp. nov. (Paraná State, Brazil.

  12. Fauna parasitária dos híbridos siluriformes cachapinta e jundiara nos primeiros estágios de desenvolvimento

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    Arlene Sobrinho Ventura

    2013-08-01

    Full Text Available O objetivo deste trabalho foi avaliar a fauna parasitária dos peixes híbridos cachapinta (Pseudoplatystoma corruscans macho x P. reticulatum fêmea e jundiara (Leiarius marmoratus macho x P. reticulatum fêmea no período de larvicultura. Um total de 315 animais, 126 híbridos jundiara e 189 híbridos cachapinta, foram examinados de acordo com o estágio de desenvolvimento: larvas, pós-larvas e alevinos. Larvas e pós-larvas foram prensadas entre lâmina e lamínula e observadas sob microscopia óptica. Os alevinos foram observados externamente em estereomicroscópio e necropsiados para avaliação interna dos órgãos. Foram aferidos os parâmetros de qualidade de água em todas as fases de cultivo. O exame parasitológico revelou a presença dos protozoários Epistylis sp. e Trichodina sp., no tegumento e nas brânquias, Ichthyophthirius multifiliis no tegumento, dos helmintos Monogenea nas brânquias, e das metacercárias de digenéticos em brânquias, baço, rins, fígado e intestino, em ambos os híbridos analisados. Os parasitos Epystilis sp., Trichodina sp. e metacercária de digenéticos ocorrem com maior frequência nos dois híbridos, nas fases de pós-larvas e alevinos. Há maior prevalência e diversidade de parasitos na fase de alevinagem dos híbridos estudados.

  13. From Desert to Dessert: Why Australian Dust Matters.

    Science.gov (United States)

    Hunter, K. A.; Mackie, D. S.; Boyd, P. W.; McTainsh, G. H.

    2006-12-01

    The growth of some types of phytoplankton in several parts of the world ocean, including much of the Southern Ocean, is limited by the supply of iron. Large Australian dust storms uplift, transport and abrade soils, to produce aeolian dust that is a significant source iron to the Southern Ocean. Atmospheric processes that enhance the dissolution of iron from aeolian dusts are of interest and have been studied for material from major dust producing regions like the Sahara, Gobi and Australian deserts; the reported solubility of iron from aeolian dusts ranges from <0.01% to 80%. The characteristic red soils, sands and dusts from Australia are generally believed to consist of quartz grains with a coating of fine grains and crystals of iron oxides, primarily hematite and goethite. The precise mineralogy of soil and dust grain coatings is poorly understood and it also not well known how the coatings are altered during uplift and transport to the ocean. Current models to understand the processes operating during the transport and atmospheric processing of dust include some generalisations and simplifications that are not always warranted and our work has shown the overlooked complexity of the system. Models for aeolian-iron dissolution based on Northern Hemisphere data commonly include the pollutants SOx and NOx. The modern Southern Hemisphere is less polluted and thus resembles past environmental systems. The dissolution of iron from soils of the Saharan, Gobi and Australian deserts in the presence of protons only (i.e. without SOx and NOx) occurs in two phases. The first, faster phase, representing up to 20% of total iron is via a surface-controlled mechanism. The rate determining variable is the exposed surface area of the iron oxides and not the size of the underlying quartz grain. The second, slower, phase of dissolution occurs via the transport-controlled formation of a leached layer. During the simulated aeolian abrasion of Australian soils from dust producing

  14. Diurnal and seasonal variations in carbon dioxide exchange in ecosystems in the Zhangye oasis area, Northwest China.

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    Lei Zhang

    Full Text Available Quantifying carbon dioxide exchange and understanding the response of key environmental factors in various ecosystems are critical to understanding regional carbon budgets and ecosystem behaviors. For this study, CO2 fluxes were measured in a variety of ecosystems with an eddy covariance observation matrix between June 2012 and September 2012 in the Zhangye oasis area of Northwest China. The results show distinct diurnal variations in the CO2 fluxes in vegetable field, orchard, wetland, and maize cropland. Diurnal variations of CO2 fluxes were not obvious, and their values approached zero in the sandy desert, desert steppe, and Gobi ecosystems. Additionally, daily variations in the Gross Primary Production (GPP, Ecosystem Respiration (Reco and Net Ecosystem Exchange (NEE were not obvious in the sandy desert, desert steppe, and Gobi ecosystems. In contrast, the distributions of the GPP, Reco, and NEE show significant daily variations, that are closely related to the development of vegetation in the maize, wetland, orchard, and vegetable field ecosystems. All of the ecosystems are characterized by their carbon absorption during the observation period. The ability to absorb CO2 differed significantly among the tested ecosystems. We also used the Michaelis-Menten equation and exponential curve fitting methods to analyze the impact of Photosynthetically Active Radiation (PAR on the daytime CO2 flux and impact of air temperature on Reco at night. The results show that PAR is the dominant factor in controlling photosynthesis with limited solar radiation, and daytime CO2 assimilation increases rapidly with PAR. Additionally, the carbon assimilation rate was found to increase slowly with high solar radiation. The light response parameters changed with each growth stage for all of the vegetation types, and higher light response values were observed during months or stages when the plants grew quickly. Light saturation points are different for different

  15. Preliminary Result of Geophysical Some Studieson the Nariinsukhait Coal Deposit

    Science.gov (United States)

    Norov, B.; Purevjav, N.; Roy, D. K., Sr.

    2017-12-01

    Nariinsukhait coal deposit has a strategic importance on Mongolian national economic development. The deposit is located in Gurvan-tes of the Umnu-gobi province, as 849 km south-west away from Ulaanbaatar. The deposit in geographically, belongs to Gobi Altai region region of the Altai mountain region. The area contains Permian, Cretaceous, Jurassic, Triassic age of sediments. Sediments are red or sedimentary cover on some part of area (Minjin. Ch., Batnyam. D., Rentsendorj. S (Baatarkhuyag. A., Altantsetseg. D., 2015). The coal deposit is located in the center portion of the Nariinsukhait basin. The age of coal hosted sedimentary rock is Jurassic estimated by Paleo-botanic methodology, using examination of a total 59 kind of plants, 288 pollen grains (Baatarkhuyag. A., Altantsetseg. D., 2015). The thickness of coal hosted sedimentary sequence is approximately 1105.5m and named as Orgilohbulag formation. In case of geophysical exploration, preliminary interpretation of the coal basin has been done by 3 geophysical methodologies which commonly applying during exploration stage of coal. The interpretations are given below. Natural Gamma Sonde /NGRS 4140/: use to determine natural gamma activation on rock by radionuclides content (238U; 235U; 232Th; 40K). During measurements well contrasted coal bedding and, value indicate between 0-15cps. And depending on the rock type it has been changed, in case of siltstone, argillite, conglomerate value fluctuated between 15-40cps. However, those rocks natural gamma values are difference little, therefore not showing much contrast between rock types. Formation Density Sonde Version B /FDSB 4036/: The Nariinsukhait coal deposit Open holes and protective pipes of density is 0.5-1.5 g/cm3, 1.2-2.3 g/cm3 respectively. Not well contrasted during measurement due to some of sedimentary rock density range is so low as such sandstone, siltstone, and conglomerate. Therefore, applied resistivity methodology and done interpretation. DLL3

  16. Variabilité selon le captureur de l'efficacité de répulsifs à base d'huiles végétales dans la protection individuelle contre les piqûres de Simulium damnosum s. l.

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    Sylla M.

    2002-12-01

    Full Text Available Dans le présent article, nous faisons état de la variabilité selon le captureur de l'efficacité de répulsifs à base d'huiles végétales appliquées sur la peau contre les piqûres de Simulium damnosum s. l. Les expérimentations ont été effectuées en zones de savane (Chaussée-Niaka et de forêt (Soubré de Côte d'Ivoire. Les formulations (lotions, crèmes] testées lors de ces travaux ont été obtenues à partir d'huiles d'amande de palme (Elaeis guineensis, de coco (Cocos nucifera et de gobi (Carapa procera. La technique classique de capture sur homme à l'aide de tubes à hémolyse en matière plastique a été utilisée. Pour chaque journée d'expérimentation, un captureur non traité (jambes non enduites de répulsif servait de témoin. Les résultats indiquent qu'en savane, quels que soient le répulsif et le captureur, la densité simulidienne se situait de 1 à 4, 1 à 6 et de 2 à 10 simulies par homme et par jour lorsque le captureur était respectivement protégé avec le coco, le palmiste et le gobi. Avec les mêmes répulsifs, en zone de forêt, l'agressivité simulidienne variait de 9 à 16, de 2 à 30 et de 8 à 49 piqûres par jour. En comparaison, le témoin recevait de 67 à 90 et de 310 à 533 piqûres par jour, respectivement en zones de savane et de forêt. Malgré les variations importantes dans le nombre de simulies capturées en fonction du captureur choisi, nos résultats montrent que quels que soient le répulsif et l'espèce simulidienne, une protection similaire est conférée à tous les captureurs. Ils indiquent également que le recours à des substances naturelles locales, utilisées comme répulsifs en application dermique, est l'une des meilleures méthodes de protection personnelle contre les simulies.

  17. Morphological selection in an extreme flow environment: body shape and waterfall-climbing success in the Hawaiian stream fish Sicyopterus stimpsoni.

    Science.gov (United States)

    Blob, Richard W; Bridges, William C; Ptacek, Margaret B; Maie, Takashi; Cediel, Roberto A; Bertolas, Morgan M; Julius, Matthew L; Schoenfuss, Heiko L

    2008-12-01

    Flow characteristics are a prominent factor determining body shapes in aquatic organisms, and correlations between body shape and ambient flow regimes have been established for many fish species. In this study, we investigated the potential for a brief period of extreme flow to exert selection on the body shape of juvenile climbing Hawaiian gobiid fishes. Because of an amphidromous life history, juvenile gobies that complete an oceanic larval phase return to freshwater habitats, where they become adults. Returning juveniles often must scale waterfalls (typically with the use of a ventral sucker) in order to reach the habitats they will use as adults, thereby exposing these animals to brief periods of extreme velocities of flow. Hydrodynamic theory predicts that bodies with larger suckers and with lower heights that reduce drag would have improved climbing success and, thus, be well suited to meet the demands of the flows in waterfalls. To test the potential for the flow environment of waterfalls to impose selection that could contribute to differences in body shape between islands, we subjected juvenile Sicyopterus stimpsoni to climbing trials up artificial waterfalls (∼100 body lengths) and measured differences in body shape between successful and unsuccessful climbers. Waterfalls appear to represent a significant selective barrier to these fishes, as nearly 30% failed our climbing test. However, the effects of selection on morphology were not straightforward, as significant differences in shape between successful and unsuccessful climbers did not always match hydrodynamic predictions. In both selection experiments and in adult fish collected from habitats with different prevailing conditions of flow (the islands of Hawai'i versus Kaua'i), lower head heights were associated with exposure to high-flow regimes, as predicted by hydrodynamic theory. Thus, a premium appears to be placed on the reduction of drag via head morphology throughout the ontogeny of this

  18. Temporal and spatial characteristics of dust devils and their contribution to the aerosol budget in East Asia-An analysis using a new parameterization scheme for dust devils

    Science.gov (United States)

    Tang, Yaoguo; Han, Yongxiang; Liu, Zhaohuan

    2018-06-01

    Dust aerosols are the main aerosol components of the atmosphere that affect climate change, but the contribution of dust devils to the atmospheric dust aerosol budget is uncertain. In this study, a new parameterization scheme for dust devils was established and coupled with WRF-Chem, and the diurnal and monthly variations and the contribution of dust devils to the atmospheric dust aerosol budget in East Asia was simulated. The results show that 1) both the diurnal and monthly variations in dust devil emissions in East Asia had unimodal distributions, with peaks in the afternoon and the summer that were similar to the observations; 2) the simulated dust devils occurred frequently in deserts, including the Gobi. The distributed area and the intensity center of the dust devil moved from east to west during the day; 3) the ratio between the availability of convective buoyancy relative to the frictional dissipation was the main factor that limited the presence of dust devils. The position of the dust devil formation, the surface temperature, and the boundary layer height determined the dust devil intensity; 4) the contribution of dust devils to atmospheric dust aerosols determined in East Asia was 30.4 ± 13%, thereby suggesting that dust devils contribute significantly to the total amount of atmospheric dust aerosols. Although the new parameterization scheme for dust devils was rough, it was helpful for understanding the distribution of dust devils and their contribution to the dust aerosol budget.

  19. Observations of carbon dioxide, methane, and carbon monoxide at Tae-Ahn peninsula (Korea), Mount Waliguan (China), Ulaan Uul (Mongolia) and at Mauna Loa (Hawaii USA)

    Energy Technology Data Exchange (ETDEWEB)

    Chung, Y.S. [Korea National Univ. of Education, Chongwon (Korea, Republic of); Tans, P.P.; Conway, T.J.; Dlugokencky, E.J. [Climate Monitoring and Diagnostics Lab., Bouler (United States); Novelli, P.C.; Tolier, M. [Colorado Univ. (United States). Cooperative Inst. for Research in Environmental Sciences; Wen, Y. [Chinese Academy of Meteorological Sciences, Beijing (China); Dagvadorj, D. [Mongolian Hydrometeorological Research Inst., Ulaan Batar (Mongolia)

    1995-12-31

    It has been discussed that the greenhouse gases, e.g. carbon dioxide (CO{sub 2}) methane (CH{sub 4}), enhance warming in the biosphere. Many scientists are therefore interested in monitoring the minor constituents of the atmosphere and in the carbon cycle. In cooperation with the Climate Monitoring and Diagnostics Laboratory (CMDL) of U.S. National Oceanic and Atmospheric Administration (NOAA), CO{sub 2}, CH{sub 4} and carbon monoxide (CO) at the western tip of the Tae-ahn Peninsula (TAP) in central Korea since October 1990 has been measured. Shortly thereafter, two more sites were added for the measurement of greenhouse gases in East Asia; one at Mount Waliguar Qinghai Province (QPC) in China and another at Ulaan Uul (UUM), the Gobi Desert in Mongolia. Also, trace gas data obtained at Mauna Loa (MLO) in Hawaii in the USA has been used. The Hawaiian data represent the world`s longest period of CO{sub 2} monitoring since 1958. The present monitoring is a part of the Global Air Sampling Network the WMO`s Global Atmospheric Watch. The method of collecting and measuring CO{sub 2}, CO and CH{sub 4} have been described else where. Here the four year monitoring of the trace gases at the three sites in East Asia is reported. The results are also compared with the measured values obtained at the free troposphere background site at MLO in Hawaii

  20. Lake Michigan offshore ecosystem structure and food web changes from 1987 to 2008

    Science.gov (United States)

    Rogers, Mark W.; Bunnell, David B.; Madenjian, Charles P.; Warner, David M.

    2014-01-01

    Ecosystems undergo dynamic changes owing to species invasions, fisheries management decisions, landscape modifications, and nutrient inputs. At Lake Michigan, new invaders (e.g., dreissenid mussels (Dreissena spp.), spiny water flea (Bythotrephes longimanus), round goby (Neogobius melanostomus)) have proliferated and altered energy transfer pathways, while nutrient concentrations and stocking rates to support fisheries have changed. We developed an ecosystem model to describe food web structure in 1987 and ran simulations through 2008 to evaluate changes in biomass of functional groups, predator consumption, and effects of recently invading species. Keystone functional groups from 1987 were identified as Mysis, burbot (Lota lota), phytoplankton, alewife (Alosa pseudoharengus), nonpredatory cladocerans, and Chinook salmon (Oncorhynchus tshawytscha). Simulations predicted biomass reductions across all trophic levels and predicted biomasses fit observed trends for most functional groups. The effects of invasive species (e.g., dreissenid grazing) increased across simulation years, but were difficult to disentangle from other changes (e.g., declining offshore nutrient concentrations). In total, our model effectively represented recent changes to the Lake Michigan ecosystem and provides an ecosystem-based tool for exploring future resource management scenarios.

  1. The offshore benthic fish community

    Science.gov (United States)

    Lantry, Brian F.; Lantry, Jana R.; Weidel, Brian C.; Walsh, Maureen; Hoyle, James A.; Schaner, Teodore; Neave, Fraser B.; Keir, Michael

    2014-01-01

    Lake Ontario’s offshore benthic fish community includes primarily slimy sculpin, lake whitefish, rainbow smelt, lake trout, burbot, and sea lamprey. Of these, lake trout have been the focus of an international restoration effort for more than three decades (Elrod et al. 1995; Lantry and Lantry 2008). The deepwater sculpin and three species of deepwater ciscoes (Coregonus spp.) that were historically important in the offshore benthic zone became rare or were extirpated by the 1960s (Christie 1973; Owens et al. 2003; Lantry et al. 2007b; Roth et al. 2013). Ecosystem changes continue to influence the offshore benthic fish community, including the effects of dreissenid mussels, the near disappearance of burrowing amphipods (Diporeia spp.) (Dermott et al. 2005; Watkins et al. 2007), and the increased abundance and expanded geographic distribution of round goby (see Nearshore Fish Community chapter) (Lantry et al. 2007b). The fish-community objectives for the offshore benthic fish community, as described by Stewart et al. (1999), are:

  2. Desert Dust and Health: A Central Asian Review and Steppe Case Study

    Directory of Open Access Journals (Sweden)

    Troy Sternberg

    2017-11-01

    Full Text Available In Asian deserts environmental and anthropomorphic dust is a significant health risk to rural populations. Natural sources in dry landscapes are exacerbated by human activities that increase the vulnerability to dust and dust-borne disease vectors. Today in Central and Inner Asian drylands, agriculture, mining, and rapid development contribute to dust generation and community exposure. Thorough review of limited dust investigation in the region implies but does not quantify health risks. Anthropogenic sources, such as the drying of the Aral Sea, highlight the shifting dust dynamics across the Central EurAsian steppe. In the Gobi Desert, our case study in Khanbogd, Mongolia addressed large-scale mining’s potential dust risk to the health of the local population. Dust traps showed variable exposure to particulates among herder households and town residents; dust density distribution indicated that sources beyond the mine need to be considered when identifying particulate sources. Research suggests that atmospheric dust from multiple causes may enhance human particulate exposure. Greater awareness of dust in greater Central Asia reflects community concern about related health implications. Future human well-being in the region will require more thorough information on dust emissions in the changing environment.

  3. Characterization of the current biological communities within the Nanticoke River in the vicinity of the Vienna SES

    International Nuclear Information System (INIS)

    Stroup, C.F.; Brindley, A.; Kazyak, P.F.

    1991-07-01

    Pursuant to a utility's intent to file for permission to build a generating station along the Nanticoke River, Maryland, a field program was conducted to update characterizations of major aquatic biota of the river in proximity to the existing power plant and a potential intake/discharge location. This characterization sampled five stations on the Nanticoke River, spanning 14 miles from Chapter Point to Riverton, between July 1988 and October 1989. During the study period, the juvenile and adult fish community was dominated by white perch, Atlantic menhaden, bay anchovy, hogchoker, and spot. Spring ichthyoplankton was composed of white perch, striped bass, yellow perch, and alosids, while summer ichthyoplankton was dominated by naked gobies and bay anchovy. Acartia tonsa, Eurytemora affinis and Bosmina longirostris dominated zooplankton samples. The phytoplankton community was composed primarily of diatoms, green algae, and monads. Polychaetes and crustaceans were the dominant macrobenthic taxa, with molluscs contributing to total abundance primarily during spring recruitment. The final report presents the results of fish, ichthyoplankton, zooplankton, and benthic surveys conducted between July 1988 and October 1989 in the middle portion of the Nanticoke River, Maryland. During the dry conditions of 1988, aquatic communities were dominated by estuarine species, while the lower saline environment of 1989 resulted in the presence of more freshwater species

  4. Increased extinction potential of insular fish populations with reduced life history variation and low genetic diversity.

    Science.gov (United States)

    Hellmair, Michael; Kinziger, Andrew P

    2014-01-01

    Theoretical work has shown that reduced phenotypic heterogeneity leads to population instability and can increase extinction potential, yet few examples exist of natural populations that illustrate how varying levels expressed diversity may influence population persistence, particularly during periods of stochastic environmental fluctuation. In this study, we assess levels of expressed variation and genetic diversity among demographically independent populations of tidewater goby (Eucyclogobius newberryi), show that reductions in both factors typically coincide, and describe how low levels of diversity contribute to the extinction risk of these isolated populations. We illustrate that, for this annual species, continuous reproduction is a safeguard against reproductive failure by any one population segment, as natural, stochastically driven salinity increases frequently result in high mortality among juvenile individuals. Several study populations deviated from the natural pattern of year-round reproduction typical for the species, rendering those with severely truncated reproductive periods vulnerable to extinction in the event of environmental fluctuation. In contrast, demographically diverse populations are more likely to persist through such periods through the continuous presence of adults with broader physiological tolerance to abrupt salinity changes. Notably, we found a significant correlation between genetic diversity and demographic variation in the study populations, which could be the result of population stressors that restrict both of these diversity measures simultaneously, or suggestive of a causative relationship between these population characteristics. These findings demonstrate the importance of biocomplexity at the population level, and assert that the maintenance of diversity contributes to population resilience and conservation of this endangered species.

  5. Both male and female identity influence variation in male signalling effort

    Directory of Open Access Journals (Sweden)

    Svensson P Andreas

    2011-08-01

    Full Text Available Abstract Background Male sexual displays play an important role in sexual selection by affecting reproductive success. However, for such displays to be useful for female mate choice, courtship should vary more among than within individual males. In this regard, a potentially important source of within male variation is adjustment of male courtship effort in response to female traits. Accordingly, we set out to dissect sources of variation in male courtship effort in a fish, the desert goby (Chlamydogobius eremius. We did so by designing an experiment that allowed simultaneous estimation of within and between male variation in courtship, while also assessing the importance of the males and females as sources of courtship variation. Results Although males adjusted their courtship depending on the identity of the female (a potentially important source of within-male variation, among-male differences were considerably greater. In addition, male courtship effort towards a pair of females was highly repeatable over a short time frame. Conclusion Despite the plasticity in male courtship effort, courtship displays had the potential to reliably convey information about the male to mate-searching females. Our experiment therefore underscores the importance of addressing the different sources contributing to variation in the expression of sexually-selected traits.

  6. Light scattering and absorption properties of dust particles retrieved from satellite measurements

    International Nuclear Information System (INIS)

    Hu, R.-M.; Sokhi, R.S.

    2009-01-01

    We use the radiative transfer model and chemistry transport model to improve our retrievals of dust optical properties from satellite measurements. The optical depth and absorbing optical depth of mineral dust can be obtained from our improved retrieval algorithm. We find the nonsphericity and absorption of dust particles strongly affect the scattering signatures such as phase function and polarization at the ultraviolet wavelengths. From our retrieval results, we find the high levels of dust concentration occurred over most desert regions such as Saharan and Gobi deserts. The dust absorption is found to be sensitive to mineral chemical composition, particularly the fraction of strongly absorbing dust particles. The enhancement of polarization at the scattering angles exceeding 120 0 is found for the nonspherical dust particles. If the polarization is neglected in the radiative transfer calculation, a maximum 50 percent error is introduced for the case of forward scattering and 25 percent error for the case of backscattering. We suggest that the application of polarimeter at the ultraviolet wavelengths has the great potential to improve the satellite retrievals of dust properties. Using refined optical model and radiative transfer model to calculate the solar radiative forcing of dust aerosols can reduce the uncertainties in aerosol radiative forcing assessment.

  7. Estimation of wind erosion from construction of a railway in arid Northwest China

    Directory of Open Access Journals (Sweden)

    Benli Liu

    2017-06-01

    Full Text Available A state-of-the-art wind erosion simulation model, the Wind Erosion Prediction System and the United States Environmental Protection Agency's AP 42 emission factors formula, were combined together to evaluate wind-blown dust emissions from various construction units from a railway construction project in the dry Gobi land in Northwest China. The influence of the climatic factors: temperature, precipitation, wind speed and direction, soil condition, protective measures, and construction disturbance were taken into account. Driven by daily and sub-daily climate data and using specific detailed management files, the process-based WEPS model was able to express the beginning, active, and ending phases of construction, as well as the degree of disturbance for the entire scope of a construction project. The Lanzhou-Xinjiang High-speed Railway was selected as a representative study because of the diversities of different climates, soil, and working schedule conditions that could be analyzed. Wind erosion from different working units included the building of roadbeds, bridges, plants, temporary houses, earth spoil and barrow pit areas, and vehicle transportation were calculated. The total wind erosion emissions, 7406 t, for the first construction area of section LXS-15 with a 14.877 km length was obtained for quantitative analysis. The method used is applicable for evaluating wind erosion from other complex surface disturbance projects.

  8. The importance of sponges and mangroves in supporting fish communities on degraded coral reefs in Caribbean Panama.

    Science.gov (United States)

    Seemann, Janina; Yingst, Alexandra; Stuart-Smith, Rick D; Edgar, Graham J; Altieri, Andrew H

    2018-01-01

    Fish communities associated with coral reefs worldwide are threatened by habitat degradation and overexploitation. We assessed coral reefs, mangrove fringes, and seagrass meadows on the Caribbean coast of Panama to explore the influences of their proximity to one another, habitat cover, and environmental characteristics in sustaining biomass, species richness and trophic structure of fish communities in a degraded tropical ecosystem. We found 94% of all fish across all habitat types were of small body size (≤10 cm), with communities dominated by fishes that usually live in habitats of low complexity, such as Pomacentridae (damselfishes) and Gobiidae (gobies). Total fish biomass was very low, with the trend of small fishes from low trophic levels over-represented, and top predators under-represented, relative to coral reefs elsewhere in the Caribbean. For example, herbivorous fishes comprised 27% of total fish biomass in Panama relative to 10% in the wider Caribbean, and the small parrotfish Scarus iseri comprised 72% of the parrotfish biomass. We found evidence that non-coral biogenic habitats support reef-associated fish communities. In particular, the abundance of sponges on a given reef and proximity of mangroves were found to be important positive correlates of reef fish species richness, biomass, abundance and trophic structure. Our study indicates that a diverse fish community can persist on degraded coral reefs, and that the availability and arrangement within the seascape of other habitat-forming organisms, including sponges and mangroves, is critical to the maintenance of functional processes in such ecosystems.

  9. Unusually dynamic sex roles in a fish.

    Science.gov (United States)

    Forsgren, Elisabet; Amundsen, Trond; Borg, Asa A; Bjelvenmark, Jens

    2004-06-03

    Sex roles are typically thought of as being fixed for a given species. In most animals males compete for females, whereas the females are more reluctant to mate. Therefore sexual selection usually acts most strongly on males. This is explained by males having a higher potential reproductive rate than females, leading to more males being sexually active (a male-biased operational sex ratio). However, what determines sex roles and the strength of sexual selection is a controversial and much debated question. In this large-scale field study, we show a striking temporal plasticity in the mating competition of a fish (two-spotted goby, Gobiusculus flavescens). Over the short breeding season fierce male-male competition and intensive courtship behaviour in males were replaced by female-female competition and actively courting females. Hence, sex role reversal occurred rapidly. This is the first time that a shift in sex roles has been shown in a vertebrate. The shift might be explained by a large decline in male abundance, strongly skewing the sex ratio towards females. Notably, the sex role reversal did not occur at an equal operational sex ratio, contrary to established sex role theory.

  10. Specializations of the mandibular anatomy and dentition of Segnosaurus galbinensis (Theropoda: Therizinosauria).

    Science.gov (United States)

    Zanno, Lindsay E; Tsogtbaatar, Khishigjav; Chinzorig, Tsogtbaatar; Gates, Terry A

    2016-01-01

    Definitive therizinosaurid cranial materials are exceptionally rare, represented solely by an isolated braincase and tooth in the North American taxon Nothronychus mckinleyi, the remarkably complete skull of the Asian taxon Erlikosaurus andrewsi, and the lower hemimandibles of Segnosaurus galbinensis. To date, comprehensive descriptions of the former taxa are published; however, the mandibular materials of S. galbinensis have remained largely understudied since their initial description in 1979. Here we provide a comprehensive description of the well-preserved hemimandibles and dentition of S. galbinensis (MPC-D 100/80), from the Upper Cretaceous Bayanshiree Formation, Gobi Desert, Mongolia. The subrectangular and ventrally displaced caudal hemimandible, extreme ventral deflection of the rostral dentary, and edentulism of the caudal dentary of S. galbinensis are currently apomorphic among therizinosaurians. Unique, unreported dental traits including lingually folded mesial carinae, development of a denticulated triangular facet on the distal carinae near the cervix, and extracarinal accessory denticles, suggest a highly specialized feeding strategy in S. galbinensis. The presence of triple carinae on the distalmost lateral tooth crowns is also unique, although may represent an abnormality. Contrasted with the simplistic dentition of the contemporaneous therizinosaurid E. andrewsi, the dentition of S. galbinensis is indicative of niche partitioning in food acquisition, processing, or resources among known therizinosaurids inhabiting Asian ecosystems in the Late Cretaceous. Although not quantitatively correlated with diet, this suite of specializations is otherwise unique among theropod dinosaurs and supports derived inferences of facultative or obligate herbivory in therizinosaurids, ultimately adding novel information to our understanding of ecomorphology in theropods.

  11. Alonzo Pond and the 1930 Logan Museum Expedition to North Africa - The Beloit College Symposium, edited by L. B. Breitborde, Logan Museum Bulletin (new series, vol. 1, no. 1, 1992

    Directory of Open Access Journals (Sweden)

    Andrew L. Christenson

    1994-11-01

    Full Text Available After a 32 year hiatus, the Logan Museum Bulletin returns with a number on the man who contributed to three of the first five numbers of the old series, Alonzo W. Pond. Pond is one of those archaeologists with a distinctive name most professionals recognize, but whose specific accom­plishments do not easily come to mind. For lithic analysts, his work on flintknapper Halvor Skavlem stands foremost (pond 1930, but for desert enthusiasts his work with Roy Chapman Andrews in the Gobi, the Rainbow Bridge-Monument Valley Expedition in the American South­ west, and Beloit College in the Sahara are most memorable. The last season of the latter expedi­tion is the focus of this slim volume, based upon a symposium given in 1985. The six chapters in the volume stand alone without an editorial structure and 50 readers are on their own to synthesize the information provided. Unfortunately, the longest contribution, Kit Hinsley's revision of a previously published (Hinsley 1989 visual analysis of late 19th century archaeological images, although of interest in the grand scale of things, sticks out as being unrelated to the concern of the volume. The author or editor should have done something to make this unrelatedness less obvious.

  12. Levels of Platinum Group Metals in Selected Species (Sarotherodon melanotheron, Chonophorus lateristriga, Macrobrachium vollenhovenii and Crassostrea tulipa in Some Estuaries and Lagoons Along the Coast of Ghana

    Directory of Open Access Journals (Sweden)

    D. K. Essumang

    2010-01-01

    Full Text Available The use of some biota as bioindicators of heavy metal pollution has been demonstrated as particularly adequate due to their capacity of bioconcentration. This study evaluated the levels of platinum group metals (PGMs in some selected species along the coastal belt of Ghana, using the neutron activation analysis (NAA method. The result was processed to evaluate pollution indices in order to map the distribution of the metals in those species in the lagoons and estuaries along the costal belt of Ghana. The analysis showed significant levels of all PGMs in blackchin tilapia (Sarotherodon melanotheron Cichlidae, brown goby (Chonophorus lateristriga Gobiidae, shrimp (Macrobrachium vollenhovenii Palaemonidae, and mangrove oysters (Crassostrea tulipa Ostreidae in the lagoons and river Pra estuary. However, the oysters showed an elevated mean concentration of 0.13 μ/g (dry weight Pd. From the pollution indices, most of the sampling sites registered mean contamination factor (CF values between 1.20 and 3.00 for Pt, Pd, and Rh. The pollution load index (PLI conducted also gave an average pollution index between 0.79 and 2.37, indicating progressive contamination levels. The results revealed that anthropogenic sources, industrial and hospital effluent, etc., together with vehicular emissions, could be the contributing factors to the deposition of PGMs along the Ghanaian coast.

  13. Salinity as the main factor structuring small-bodied fish assemblages in hydrologically altered Mediterranean coastal lagoons

    Directory of Open Access Journals (Sweden)

    Sílvia Rodríguez-Climent

    2013-03-01

    Full Text Available In the Ebro Delta coastal lagoons, one of the main anthropogenic pressures is the artificial freshwater input. Each coastal lagoon has different water management schemes causing profound changes in its physicochemical characteristics. The main objective of this water management is to favour some bird species with interest either for conservation or hunting activities. The present study assesses the influence of hydrological alteration on the fish assemblages of three coastal lagoons in the Ebro Delta. The small-bodied fish fauna was mainly composed of five families: Gobiidae, Poecilidae, Cyprinodontidae, Atherinidae and Mugilidae. Salinity was found to be the main factor structuring fish community in the lagoons. The dominant species was the common goby (Pomatochistus microps when the lagoons reached higher salinity values, whereas the invasive eastern mosquitofish (Gambusia holbrooki dominated during the period of higher freshwater inputs. The juveniles of the family Mugilidae showed low catch per unit effort, especially during the period of lower salinity. This same pattern was found for the endangered Spanish toothcarp (Aphanius iberus. Overall, introduced species were favoured by low salinity, which highlights the importance of changing the present water management by reducing the freshwater inputs in order to maintain suitable levels of salinity to favour native species that are important for both commercial and conservation purposes.

  14. Deinococcus gobiensis cold shock protein improves salt stress tolerance of escherichia coli

    International Nuclear Information System (INIS)

    Jiang Shijie; Wang Jin; Yang Mingkun; Chen Ming; Zhang Wei; Luo Xuegang

    2013-01-01

    The Deinococcus gobiensis I-0, an extremely radiation-resistant bacterium, isolated from the Gobi, has superior resistance to abiotic stress (e.g radiation, oxidation, dehydration and so on). The two cold-shock proteins encoded by csp1 (Dgo_CA1136) and csp2 (Dgo_PA0041) were identified in the complete genome sequence of D. gobiensis. In this study, we showed that D. gobiensis Csp1 protected Escherichia coli cells against cold shock and other abiotic stresses such as salt and osmotic shocks. The quantitative real-time PCR assay shows that the expression of trehalose synthase (otsA, otsB) was up-regulated remarkably under salt stress in the csp1-expressing strain, while no difference in the expression of the genes involved in trehalose degradation (treB and treC). The results suggested that Csp1 caused the accumulation of the trehalose was a major feature for improving tolerance to salt stress in E. coli. (authors)

  15. Hypoxia tolerance in coral-reef triggerfishes (Balistidae)

    Science.gov (United States)

    Wong, Corrie C.; Drazen, Jeffrey C.; Callan, Chatham K.; Korsmeyer, Keith E.

    2018-03-01

    Despite high rates of photosynthetic oxygen production during the day, the warm waters of coral reefs are susceptible to hypoxia at night due to elevated respiration rates at higher temperatures that also reduce the solubility of oxygen. Hypoxia may be a challenge for coral-reef fish that hide in the reef to avoid predators at night. Triggerfishes (Balistidae) are found in a variety of reef habitats, but they also are known to find refuge in reef crevices and holes at night, which may expose them to hypoxic conditions. The critical oxygen tension ( P crit) was determined as the point below which oxygen uptake could not be maintained to support standard metabolic rate (SMR) for five species of triggerfish. The triggerfishes exhibited similar levels of hypoxia tolerance as other coral-reef and coastal marine fishes that encounter low oxygen levels in their environment. Two species, Rhinecanthus rectangulus and R. aculeatus, had the lowest P crit ( 3.0 kPa O2), comparable to the most hypoxia-tolerant obligate coral-dwelling gobies, while Odonus niger and Sufflamen bursa were moderately tolerant to hypoxia ( P crit 4.5 kPa), and Xanthichthys auromarginatus was intermediate ( P crit 3.7 kPa). These differences in P crit were not due to differences in oxygen demand, as all the species had a similar SMR once mass differences were taken into account. The results suggest that triggerfish species are adapted for different levels of hypoxia exposure during nocturnal sheltering within the reef.

  16. Risk factors associated with white spot syndrome virus infection in a Vietnamese rice-shrimp farming system.

    Science.gov (United States)

    Corsin, F; Turnbull, J F; Hao, N V; Mohan, C V; Phi, T T; Phuoc, L H; Tinh, N T; Morgan, K L

    2001-10-29

    White spot disease (WSD) is a pandemic disease caused by a virus commonly known as white spot syndrome virus (WSSV). Several risk factors for WSD outbreaks have been suggested. However, there have been very few studies to identify risk factors for WSD outbreaks in culture systems. This paper presents and discusses the risk factors for WSSV infection identified during a longitudinal observational study conducted in a Vietnamese rice-shrimp farming system. A total of 158 variables were measured comprising location, features of the pond, management practices, pond bottom quality, shrimp health and other animals in the pond. At the end of the study period WSSV was detected in 15 of the 24 ponds followed through the production cycle (62.5%). One hundred and thirty-nine variables were used in univariate analyses. All the variables with a p-value Hemigrapsus spp. crabs during the first month of production, feeding vitamin premix or legumes, presence of high numbers of shrimp with bacterial infection and the presence of larger mud crabs or gobies at harvest. No associations were detected with WSSV at harvest and stocking density, presence, or number or weight of wild shrimp in the pond. The multivariate model to identify outcomes associated with WSSV infection highlighted the presence of high mortality as the main variable explaining the data. The results obtained from this study are discussed in the context of WSD control and areas requiring further investigation are suggested.

  17. Determining the Frequency of Dry Lake Bed Formation in Semi-Arid Mongolia From Satellite Data

    Directory of Open Access Journals (Sweden)

    Yuta Demura

    2017-12-01

    Full Text Available In the Mongolian Plateau, the desert steppe, mountains, and dry lake bed surfaces may affect the process of dust storm emissions. Among these three surface types, dry lake beds are considered to contribute a substantial amount of global dust emissions and to be responsible for “hot spots” of dust outbreaks. The land cover types in the study area were broadly divided into three types, namely desert steppe, mountains, and dry lake beds, by a classification based on Normalized Difference Water Index (NDWI calculated from MODIS Terra satellite images, and Digital Elevation Model (DEM. This dry lake beds extracting method using remote sensing offers a new technique for identifying dust hot spots and potential untapped groundwater in the dry lands of the Gobi region. In the study area, frequencies of dry lake bed formation were calculated during the period of 2001 to 2014. The potential dry lake area corresponded well with the length of the river network based on hydrogeological characterization (R2 = 0.77, p < 0.001. We suggest that the threshold between dry lake bed areas and the formation of ephemeral lakes in semi-arid regions is eight days of total precipitation.

  18. Drinking by amphibious fish: convergent evolution of thirst mechanisms during vertebrate terrestrialization.

    Science.gov (United States)

    Katayama, Yukitoshi; Sakamoto, Tatsuya; Saito, Kazuhiro; Tsuchimochi, Hirotsugu; Kaiya, Hiroyuki; Watanabe, Taro; Pearson, James T; Takei, Yoshio

    2018-01-12

    Thirst aroused in the forebrain by angiotensin II (AngII) or buccal drying motivates terrestrial vertebrates to search for water, whereas aquatic fish can drink surrounding water only by reflex swallowing generated in the hindbrain. Indeed, AngII induces drinking through the hindbrain even after removal of the whole forebrain in aquatic fish. Here we show that AngII induces thirst also in the amphibious mudskipper goby without direct action on the forebrain, but through buccal drying. Intracerebroventricular injection of AngII motivated mudskippers to move into water and drink as with tetrapods. However, AngII primarily increased immunoreactive c-Fos at the hindbrain swallowing center where AngII receptors were expressed, as in other ray-finned fish, and such direct action on the forebrain was not found. Behavioural analyses showed that loss of buccal water on land by AngII-induced swallowing, by piercing holes in the opercula, or by water-absorptive gel placed in the cavity motivated mudskippers to move to water for refilling. Since sensory detection of water at the bucco-pharyngeal cavity like 'dry mouth' has recently been noted to regulate thirst in mammals, similar mechanisms seem to have evolved in distantly related species in order to solve osmoregulatory problems during terrestrialization.

  19. Inclusion of Solar Elevation Angle in Land Surface Albedo Parameterization Over Bare Soil Surface.

    Science.gov (United States)

    Zheng, Zhiyuan; Wei, Zhigang; Wen, Zhiping; Dong, Wenjie; Li, Zhenchao; Wen, Xiaohang; Zhu, Xian; Ji, Dong; Chen, Chen; Yan, Dongdong

    2017-12-01

    Land surface albedo is a significant parameter for maintaining a balance in surface energy. It is also an important parameter of bare soil surface albedo for developing land surface process models that accurately reflect diurnal variation characteristics and the mechanism behind the solar spectral radiation albedo on bare soil surfaces and for understanding the relationships between climate factors and spectral radiation albedo. Using a data set of field observations, we conducted experiments to analyze the variation characteristics of land surface solar spectral radiation and the corresponding albedo over a typical Gobi bare soil underlying surface and to investigate the relationships between the land surface solar spectral radiation albedo, solar elevation angle, and soil moisture. Based on both solar elevation angle and soil moisture measurements simultaneously, we propose a new two-factor parameterization scheme for spectral radiation albedo over bare soil underlying surfaces. The results of numerical simulation experiments show that the new parameterization scheme can more accurately depict the diurnal variation characteristics of bare soil surface albedo than the previous schemes. Solar elevation angle is one of the most important factors for parameterizing bare soil surface albedo and must be considered in the parameterization scheme, especially in arid and semiarid areas with low soil moisture content. This study reveals the characteristics and mechanism of the diurnal variation of bare soil surface solar spectral radiation albedo and is helpful in developing land surface process models, weather models, and climate models.

  20. How to allocate water resources under climate change in the arid endorheic river basin, Northwest China

    Science.gov (United States)

    Zhang, A.; Feng, D.; Tian, Y.; Zheng, Y.

    2017-12-01

    Water resource is of fundamental importance to the society and ecosystem in arid endorheic river basins, and water-use conflicts between upstream and downstream are usually significant. Heihe river basin (HRB) is the second largest endorheic river basin in china, which is featured with dry climate, intensively irrigated farmlands in oases and significant surface water-groundwater interaction. The irrigation districts in the middle HRB consume a large portion of the river flow, and the low HRB, mainly Gobi Desert, has an extremely vulnerable ecological environment. The water resources management has significantly altered the hydrological processes in HRB, and is now facing multiple challenges, including decline of groundwater table in the middle HRB, insufficient environmental flow for the lower HRB. Furthermore, future climate change adds substantial uncertainty to the water system. Thus, it is imperative to have a sustainable water resources management in HRB in order to tackle the existing challenges and future uncertainty. Climate projection form a dynamical downscaled climate change scenario shows precipitation will increase at a rate of approximately 3 millimeter per ten years and temperature will increase at a rate of approximately 0.2 centigrade degree per ten years in the following 50 years in the HRB. Based on an integrated ecohydrological model, we evaluated how the climate change and agricultural development would collaboratively impact the water resources and ecological health in the middle and lower HRB, and investigated how the water management should cope with the complex impact.

  1. Investigation for the ecology in areas nearby a nuclear facility

    International Nuclear Information System (INIS)

    Qin Suyun; Zhou Caiyun; Zhou Zirong; Chen Wenying; Zhen Zhijiang

    1995-03-01

    Studies were undertaken for the general ecological environment around the evaporating ponds and Gobi desert areas receiving the low and very low level radioactive waste water from a nuclear facility and for the transport of radionuclides in food chains were undertaken. On basis of obtained results the following conclusions were made: (1) In consequence of controlled releases of low level radioactive waste water, a steady specific ecosystem had formed. (2) Concentration of radionuclides in sediments, soils, terrestrial and aquatic wild plants and animals, agricultural products irrigated with very low level radioactive waste water, and tissues of sheep pastured in very low level radioactive water drainage areas, were higher significantly than that of non-contaminated areas. (3) Radioactive waste water discharging might result in potential exposure to members of residents. The critical radionuclide was 137 Cs, and the critical pathway was ingesting polluted waterfowls of evaporating pond. On basis of very conservative assessing the maximum intake of 137 Cs of individual of local resident was 1.0 x 10 4 Bq·a -1 corresponding to 50% of ALI of individual of population. Maximum amount of redistribution of radioactive material as a result of carrying by migrating birds under extreme conditions might be about 10 7 Bq·a -1 . (16 refs., 9 tabs., 1 fig.)

  2. Long-term changes of fisheries landings in enclosed gulf lagoons (Amvrakikos gulf, W Greece): Influences of fishing and other human impacts

    Science.gov (United States)

    Katselis, George N.; Moutopoulos, Dimitrios K.; Dimitriou, Evagelos N.; Koutsikopoulos, Constantin

    2013-10-01

    The present study analyses long-term annual fishery landings time series (1980-2007) for species derived from six lagoons (covering about 70 km2) around an important European wetland, the fjord-like Amvrakikos gulf. Landing trends for most abundant species revealed that typical lagoon fish species-groups, such as Mugilidae (Mugil cephalus, Chelon labrosus, Liza saliens, Liza aurata and Liza ramada), eels (Anguilla anguilla) and Gobies (mainly Zosteriosessor ophiocephalus) had largely decreased, while the landings of Sparus aurata increased during the entire study period. These trends led to a significant change in species composition during recent years that might be attributed to large-scale climatic changes as well as serious anthropogenic impacts that degraded the water quality and altered the hydrology within the gulf and lagoons, the increase of fishing exploitation in Amvrakikos gulf, the expansion of aquaculture activities within the gulf, the application of new fishing management practices in lagoons, and the increase of fish-eating sea-bird populations. The findings are needed for the implementation of an efficient and integrated management tool for the study of coastal systems.

  3. Aerosol contamination survey during dust storm process in Northwestern China using ground, satellite observations and atmospheric modeling data

    Science.gov (United States)

    Filonchyk, Mikalai; Yan, Haowen; Shareef, Tawheed Mohammed Elhessin; Yang, Shuwen

    2018-01-01

    The present survey addresses the comprehensive description of geographic locations, transport ways, size, and vertical aerosol distribution during four large dust events which occurred in the Northwest China. Based on the data from 35 ground-based air quality monitoring stations and the satellite data, emission flows for dust events within the period of 2014 to 2017 have been estimated. The data show that maximum peak daily average PM10 and PM2.5 concentrations exceeded 380 and 150 μg/m3, respectively, and the PM2.5/PM10 ratio was ranging within 0.12-0.66. Both satellite data and simulation data of the Hybrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) coincide with location and extension of a dust cloud. The Cloud Aerosol Lidar and Infrared Pathfinder Satellite Observations (CALIPSO) found dust at 0 to 10 km altitude which remained at this level during the most part of its trajectory. The vertical aerosol distribution at a wave of 532 nm total attenuated backscatter coefficient range of 0.0025-0.003 km-1 × sr-1. Moderate Resolution Imaging Spectroradiometer (MODIS) (Terra) Collection 6 Level-3 aerosol products data show that aerosol optical depth (AOD) at pollution epicenters exceeds 1. A comprehensive data survey thus demonstrated that the main sources of high aerosol pollutions in the territory were deserted areas of North and Northwest China as well as the most part of the Republic of Mongolia, where one of the largest deserts, Gobi, extends.

  4. Evaluating natural radiation level by existing airborne radioactive data

    International Nuclear Information System (INIS)

    Mingkao, Hu; Changqing, Han; Jiangqi, Fang; Zhengxin, Shen

    2002-01-01

    Airborne Survey and Remote Sensing Center of Nuclear Industry, founded in the middle of 1950s, is a unique unit specialized in uranium exploration by airborne radioactive survey in China. Large numbers of airborne data of radioactivity and abundant experience have been accumulated for more than 40 years. All-round detailed investigation of environmental radiation levels in our country will not be completed in the near future. Thus, at present it is considered to evaluate natural radiation levels using the existing radioactive data. This paper introduces the results of analysis and study comparing airborne radioactive data for radiation environmental evaluation obtained from survey area in Gansu, China, in the 2001 with the measurement results by ground gamma ray radiation dose-rate instrument for environment. The air-earth inter-comparison error does not exceed 30% at radiation fields with a definite area, and the air-earth inter-comparison error does not exceed 60% at outcrop of granite. In 6km long profile that has various circumstances, such as desert, Gobi, farmland and residential area, minimum of air absorbed dose rate is 47nGy/h at an altitude of 1 meter above the soil plane, maximum is 68nGy/h. The inter-comparison errors are usually less than 20%, and maximum is 25.38%. This shows that it is feasible to obtain natural radiation levels rapidly if we could use the existing radioactive data adequately and make some correction, such as geology factor

  5. Impacts of aquatic nonindigenous invasive species on the Lake Erie ecosystem

    Science.gov (United States)

    Austen, Madeline J.W.; Ciborowski, Jan J.H.; Corkum, Lynda D.; Johnson, Tim B.; MacIsaac, Hugh J.; Metcalfe-Smith, Janice L.; Schloesser, Donald W.; George, Sandra E.

    2002-01-01

    Lake Erie is particularly vulnerable to the introduction and establishment of aquatic nonindigenous invasive species (NIS) populations. A minimum of 144 aquatic NIS have been recorded in the Lake Erie basin including several species [e.g., Eurasian watermilfoil (Myriophyllum spicatum); zebra mussel (Dreissena polymorpha); quagga mussel (Dreissena bugensis); an amphipod (Echinogammarus ischnus); round goby (Neogobius melanostomus); and sea lamprey (Petromyzon marinus)] that have had discernible impacts on the lake's ecology. NIS pose threats to the Lake Erie ecosystem for a variety of reasons including their ability to proliferate quickly, compete with native species, and transfer contaminants (e.g., PCBs) and disease through the food web. Six of the 14 beneficial use impairments listed in Annex 2 of the Great Lakes Water Quality Agreement are impaired in Lake Erie, in part as a result of the introduction of NIS. The Lake Erie Lakewide Management Plan (LaMP) has adopted an ecosystem approach to restore beneficial use impairments in the lake. Furthermore, a research consortium, known as the Lake Erie Millennium Network, is working alongside the LaMP, to address research problems regarding NIS, the loss of habitat, and the role of contaminants in the Lake Erie ecosystem.

  6. Individual adjustment of sperm expenditure accords with sperm competition theory.

    Science.gov (United States)

    Pilastro, Andrea; Scaggiante, Marta; Rasotto, Maria B

    2002-07-23

    Sperm competition theory predicts that males should strategically allocate their sperm reserves according to the level of sperm competition, defined as the probability that the sperm of two males compete for fertilizing a given set of ova. Substantial evidence from numerous animal taxa suggests that, at the individual level, sperm expenditure increases when the risk of sperm competition is greater. In contrast, according to the "intensity model" of sperm competition [Parker, G. A., Ball, M. A., Stockley, P. & Gage, M. J. G. (1996) Proc. R. Soc. London Ser. B 263, 1291-1297], when more than two ejaculates compete during a given mating event, sperm expenditure should decrease as the number of competing males increases. Empirical evidence supporting this prediction, however, is still lacking. Here we measured sperm expenditure in two gobiid fishes, the grass (Zosterisessor ophiocephalus) and black goby (Gobius niger), in which up to six sneakers can congregate around the nest of territorial males and release their sperm when females spawn. We show that, in accordance with theory, sneaker males of both species release fewer sperm as the number of competitors increases.

  7. New Mediterranean Marine biodiversity records (June 2013

    Directory of Open Access Journals (Sweden)

    I. SIOKOU

    2013-04-01

    Full Text Available This paper concerns records of species that have extended their distribution in the Mediterranean Sea. The finding of the rare brackish angiosperm Althenia filiformis in the island of Cyprus is interesting since its insertion in the Red Data Book of the Flora of Cyprus is suggested. The following species enriched the flora or fauna lists of the relevant countries: the red alga Sebdenia dichotoma (Greece, the hydrachnid mite Pontarachna adriatica (Slovenia, and the thalassinid Gebiacantha talismani (Turkey. Several alien species were recorded in new Mediterranean localities. The record of the burrowing goby Trypauchen vagina in the North Levantine Sea (Turkish coast, suggests the start of spreading of this Lessepsian immigrant in the Mediterranean Sea. The findings of the following species indicate the extension of their occurrence in the Mediterranean Sea: the foraminifer Amphistegina lobifera (island of Zakynthos, Greece, the medusa Cassiopea andromeda (Syria, the copepod Centropages furcatus (Aegean Sea, the decapod shrimp Melicertus hathor (island of Kastellorizo, Greece, the crab Menoethius monoceros (Gulf of Tunis, the barnacles Balanus trigonus, Megabalanus tintinnabulum, Megabalanus coccopoma and the bivalves Chama asperella, Cucurbitula cymbium (Saronikos Gulf, Greece.

  8. Mapping Palaeohydrography in Deserts: Contribution from Space-Borne Imaging Radar

    Directory of Open Access Journals (Sweden)

    Philippe Paillou

    2017-03-01

    Full Text Available Space-borne Synthetic Aperture Radar (SAR has the capability to image subsurface features down to several meters in arid regions. A first demonstration of this capability was performed in the Egyptian desert during the early eighties, thanks to the first Shuttle Imaging Radar mission. Global coverage provided by recent SARs, such as the Japanese ALOS/PALSAR sensor, allowed the mapping of vast ancient hydrographic systems in Northern Africa. We present a summary of palaeohydrography results obtained using PALSAR data over large deserts such as the Sahara and the Gobi. An ancient river system was discovered in eastern Lybia, connecting in the past the Kufrah oasis to the Mediterranean Sea, and the terminal part of the Tamanrasett river was mapped in western Mauritania, ending with a large submarine canyon. In southern Mongolia, PALSAR images combined with topography analysis allowed the mapping of the ancient Ulaan Nuur lake. We finally show the potentials of future low frequency SAR sensors by comparing L-band (1.25 GHz and P-band (435 MHz airborne SAR acquisitions over a desert site in southern Tunisia.

  9. 10Be in desert sands, falling dust and loess in China

    International Nuclear Information System (INIS)

    Shen, C.D.; Beer, J.; Kubik, P.W.; Sun, W.D.; Liu, T.S.; Liu, K.X.

    2010-01-01

    Cosmogenic 10 Be is produced in the atmosphere, and deposits onto the surface of the earth mainly through wet precipitation and dust. Based on the analysis of 10 Be in Chinese loess, we believe that 10 Be in loess is composed of two components: locally precipitated atmospheric 10 Be, and windblown 10 Be adsorbed on the surface of silt grains. On the Loess Plateau, 10 Be concentrations in loess and paleosol range from (1.4 to 2.8) x 10 8 atoms/g and (2.7 to 4.5) x 10 8 atoms/g, respectively. To investigate the sources of 10 Be in loess, we measured 10 Be in sand grains from deserts in western China and falling dust from the deposition regions. The results show that the 10 Be concentrations in sand and dust are (1.1-5.1) x 10 7 atoms/g and (1.3-2.8) x 10 8 atoms/g, respectively. Loess and paleosol on the Loess Plateau both contain inherited 10 Be adsorbed on silt grains from dust; most of the windblown deposited loess materials do not directly come from the Gobi and other sand deserts, but mainly from the loess-desert transitional zones, which are characterized by silt and dust holding areas.

  10. The right place for the right job in the photovoltaic life cycle.

    Science.gov (United States)

    Kawajiri, Kotaro; Genchi, Yutaka

    2012-07-03

    The potential for photovoltaic power generation (PV) to reduce primary energy consumption (PEC) and CO(2) emissions depends on the physical locations of each stage of its life cycle. When stages are optimally located, CO(2) emissions are reduced nearly ten times as much as when each stage is located in the country having the largest current market share. The usage stage contributes the most to reducing CO(2) emissions and PEC, and total CO(2) emissions actually increase when PV is installed in countries having small CO(2) emissions from electricity generation. Global maps of CO(2) reduction potential indicate that Botswana and Gobi in Mongolia are the optimal locations to install PV due to favorable conditions for PV power generation and high CO(2) emissions from current electricity generation. However, the small electricity demand in those countries limits the contribution to global CO(2) reduction. The type of PVs has a small but significant effect on life cycle PEC and CO(2) emissions.

  11. The taxonomy of a new parvicursorine alvarezsauroid specimen IVPP V20341 (Dinosauria: Theropoda from the Upper Cretaceous Wulansuhai Formation of Bayan Mandahu, Inner Mongolia, China

    Directory of Open Access Journals (Sweden)

    Michael Pittman

    2015-06-01

    Full Text Available A new parvicursorine alvarezsauroid theropod specimen IVPP V20341 from the Upper Cretaceous Wulansuhai Formation of Bayan Mandahu, Inner Mongolia, China is described. IVPP V20341 appears to be distinguishable amongst alvarezsauroids by possible cervical procoely and relatively larger semi-circular caudal neural canals, but these features are not proposed as autapomorphies because current knowledge of alvarezsauroid necks and tails remains sparse. IVPP V20341 is distinguishable from Linhenykus—the sole parvicursorine at Bayan Mandahu—by the location of the origination points of the anterior caudal transverse processes; in IVPP V20341 this is the anterodorsal corner of the centra, whereas in Linhenykus it is the posterior end of the prezygapophyses. A number of additional tentative differences between IVPP V20341 and Linhenykus are also identified, but cannot be confirmed until further details of anatomical variation along the neck and tail are revealed by future finds. Thus, following the study of IVPP V20341 there are still seven parvicursorine species from the Upper Cretaceous Gobi Basin, but future finds could increase this to eight species.

  12. Ensemble forecasting of potential habitat for three invasive fishes

    Science.gov (United States)

    Poulos, Helen M.; Chernoff, Barry; Fuller, Pam L.; Butman, David

    2012-01-01

    Aquatic invasive species pose major ecological and economic threats to aquatic ecosystems worldwide via displacement, predation, or hybridization with native species and the alteration of aquatic habitats and hydrologic cycles. Modeling the habitat suitability of alien aquatic species through spatially explicit mapping is an increasingly important risk assessment tool. Habitat modeling also facilitates identification of key environmental variables influencing invasive species distributions. We compared four modeling methods to predict the potential continental United States distributions of northern snakehead Channa argus (Cantor, 1842), round goby Neogobius melanostomus (Pallas, 1814), and silver carp Hypophthalmichthys molitrix (Valenciennes, 1844) using maximum entropy (Maxent), the genetic algorithm for rule set production (GARP), DOMAIN, and support vector machines (SVM). We used inventory records from the USGS Nonindigenous Aquatic Species Database and a geographic information system of 20 climatic and environmental variables to generate individual and ensemble distribution maps for each species. The ensemble maps from our study performed as well as or better than all of the individual models except Maxent. The ensemble and Maxent models produced significantly higher accuracy individual maps than GARP, one-class SVMs, or DOMAIN. The key environmental predictor variables in the individual models were consistent with the tolerances of each species. Results from this study provide insights into which locations and environmental conditions may promote the future spread of invasive fish in the US.

  13. Digitization of uranium deposit information in basin. A new strategy of ISL sandstone-type uranium deposits exploration

    International Nuclear Information System (INIS)

    Tan Chenglong

    2006-01-01

    The discovered ISL sandstone-type uranium deposits in the entire world are mostly blind deposits, many of them occur in bleak desert, gobi desert, and semi-hilly land area. Exploration methods for these deposits mainly depend on great and systematic drilling. There are many large-medium size Meso-Cenozoic sedimentary basins in northern China, and over twenty of them are thick overburden basins which are mostly the virgin land for ISL sandstone-type uranium deposit. Due to the comprehensive national power, geological background, uranium exploration ability, great and systematic drilling is not favorable for prospecting ISL sandstone-type uranium deposit in China. According to the exploration and prospecting experiences for mineral ore bodies at home and abroad, uranium information mapping based on geochemical survey of the basins is a new strategy for ISL sandstone-type uranium deposits. It is an economic, practical, fast and effective method, and has been manifested by the performing information digitization for oil and gas resources, gold mineral resources in China and the mapping of uranium information for whole Europe continent. (authors)

  14. A simplified Suomi NPP VIIRS dust detection algorithm

    Science.gov (United States)

    Yang, Yikun; Sun, Lin; Zhu, Jinshan; Wei, Jing; Su, Qinghua; Sun, Wenxiao; Liu, Fangwei; Shu, Meiyan

    2017-11-01

    Due to the complex characteristics of dust and sparse ground-based monitoring stations, dust monitoring is facing severe challenges, especially in dust storm-prone areas. Aim at constructing a high-precision dust storm detection model, a pixel database, consisted of dusts over a variety of typical feature types such as cloud, vegetation, Gobi and ice/snow, was constructed, and their distributions of reflectance and Brightness Temperatures (BT) were analysed, based on which, a new Simplified Dust Detection Algorithm (SDDA) for the Suomi National Polar-Orbiting Partnership Visible infrared Imaging Radiometer (NPP VIIRS) is proposed. NPP VIIRS images covering the northern China and Mongolian regions, where features serious dust storms, were selected to perform the dust detection experiments. The monitoring results were compared with the true colour composite images, and results showed that most of the dust areas can be accurately detected, except for fragmented thin dusts over bright surfaces. The dust ground-based measurements obtained from the Meteorological Information Comprehensive Analysis and Process System (MICAPS) and the Ozone Monitoring Instrument Aerosol Index (OMI AI) products were selected for comparison purposes. Results showed that the dust monitoring results agreed well in the spatial distribution with OMI AI dust products and the MICAPS ground-measured data with an average high accuracy of 83.10%. The SDDA is relatively robust and can realize automatic monitoring for dust storms.

  15. Integrated heart failure telemonitoring system for homecare.

    Science.gov (United States)

    Lobodzinski, S Suave; Jadalla, Ahlam A

    2010-01-01

    The integrated telemonitoring system (ITS) for homecare has been designed to improve quality of care as measured by increased nursing productivity, improved patients' clinical and behavioral outcomes and reduction of cost. The system incorporates managerial, organizational, operational and clinical tasks optimized for delivery of quality care through telemonitoring. A secure, multi-modal computer network that integrates homecare nurses, patients and those who care into one seamless environment has been developed. The network brings together a new generation of small, hand-held, wireless terminals used by nurses and patients with a HIPPA-compliant electronic patient record system at the caregiver's site. Wireless terminals use Gobi multi-standard networking technology for connectivity to any available wireless network. The unique features of ITS include a) picture recognition technology capable of extracting numeric data from in-home physiological signal monitor displays that include blood pressure, weight, oxygen saturation, transmission of lung sounds, and capturing echocardiography and electrocardiography data from mobile units; b) in-home caregiver-assisted interactive examinations of signs and symptoms that include visual impressions of ankle swelling, jugular vein distension measurement, and weight gain; c) video-conference capability, facilitating face-to-face two-way communication of nursing personnel with the patients. The ITS network has been designed to improve patients' clinical and behavioral outcomes, increase nursing productivity, and reduce the cost of homecare. Patients' co-operation and compliance has been achieved through use of easy-to-use videoconferencing terminals.

  16. New Mediterranean Marine biodiversity records (December, 2013

    Directory of Open Access Journals (Sweden)

    M. BILECENOGLU

    2013-10-01

    Full Text Available Based on recent biodiversity studies carried out in different parts of the Mediterranean, the following 19 species are included as new records on the floral or faunal lists of the relevant ecosystems: the green algae Penicillus capitatus (Maltese waters; the nemertean Amphiporus allucens (Iberian Peninsula, Spain; the salp Salpa maxima (Syria; the opistobranchs Felimida britoi and Berghia coerulescens (Aegean Sea, Greece; the dusky shark Carcharhinus obscurus (central-west Mediterranean and Ionian Sea, Italy; Randall’s threadfin bream Nemipterus randalli, the broadbanded cardinalfish Apogon fasciatus and the goby Gobius kolombatovici (Aegean Sea, Turkey; the reticulated leatherjack Stephanolepis diaspros and the halacarid Agaue chevreuxi (Sea of Marmara, Turkey; the slimy liagora Ganonema farinosum, the yellowstripe barracuda Sphyraena chrysotaenia, the rayed pearl oyster Pinctada imbricata radiata and the Persian conch Conomurex persicus (south-eastern Crete, Greece; the blenny Microlipophrys dalmatinus and the bastard grunt Pomadasys incisus (Ionian Sea, Italy; the brown shrimp Farfantepenaeus aztecus (north-eastern Levant, Turkey; the blue-crab Callinectes sapidus (Corfu, Ionian Sea, Greece. In addition, the findings of the following rare species improve currently available biogeographical knowledge: the oceanic pufferfish Lagocephalus lagocephalus (Malta; the yellow sea chub Kyphosus incisor (Almuñécar coast of Spain; the basking shark Cetorhinus maximus and the shortfin mako Isurus oxyrinchus (north-eastern Levant, Turkey.

  17. The community structure of over-wintering larval and small juvenile fish in a large estuary

    Science.gov (United States)

    Munk, Peter; Cardinale, Massimiliano; Casini, Michele; Rudolphi, Ann-Christin

    2014-02-01

    The Skagerrak and Kattegat are estuarine straits of high hydrographical and ecological diversity, situated between the saline waters of the North Sea and the brackish waters of the Baltic Sea. These sustain important nursery grounds of many fish species, of which several overwinter during the larval and early juvenile stages. In order to give more insight into the communities of the overwintering ichthyoplankton in estuarine areas, we examine an annual series of observations from a standard survey carried out 1992-2010. Species differences and annual variability in distributions and abundances are described, and linkages between ichthyoplankton abundances and corresponding hydrographical information are analysed by GAM methods. Communities were dominated by herring, gobies, butterfish, sprat, pipefishes, lemon sole and European eel (i.e. glass eel), and all the sampled species showed large annual fluctuations in abundances. The species showed quite specific patterns of distribution although species assemblages with common distributional characteristics were identified. Within these assemblages, the ichthyoplankton abundances showed linkage to environmental characteristics described by bottom-depth and surface temperature and salinity. Hence the study points to a significant structuring of overwintering ichthyoplankton communities in large estuaries, based on the species habitat choice and its response to physical gradients.

  18. An analysis of the correlation between dust storms in Korea and 137Cs nuclide concentration

    International Nuclear Information System (INIS)

    Choi, Soo-won; Kim, Jeong-hun; Shin, Sang-hwa; Hwang, Joo-ho

    2008-01-01

    Dust storms occur in Korea during spring time when fine dust is blown in from the far western regions of western China and Mongolia. A fine powdery dust is blown up into the sky and enters the upper reaches of the atmosphere where it is carried easterly across China then slowly falls to the ground on the Korean peninsula and Japan. The dust originates mostly in the Gobi dessert of China, as well as the yellow earth regions in the middle and upper streams of the Yellow river in China. Previous studies on dust storms have been limited to following or estimating their courses, distribution and frequency, or distribution of the heavy metals they transmit. However, since radionuclides exist in the dust, they must also exist in the dust storms. In this study, we analyzed the correlation of :1 37 Cs nuclide concentration based on a count of annual dust storm occurrence in the city of Suwon, South Korea and assessed seasonal differences of 137 Cs nuclide concentration

  19. {sup 241}Pu concentrations in water, plankton and fish from the southern Baltic Sea

    Energy Technology Data Exchange (ETDEWEB)

    Struminska-Parulska, D.I.; Skwarzec, B. [Gdansk, Univ. (Poland). Facuty of Chemistry

    2013-08-01

    The aim of the work was to determine {sup 241}Pu activities in different components (water, plankton and fish) of the southern Baltic Sea ecosystem. Measurement of {sup 241}Pu in the samples was done indirectly by determining the increment in {sup 241}Am from the decay of the {beta}-emitting {sup 241}Pu in samples collected 10-15 years after the Chernobyl accident. Enhanced levels of {sup 241}Pu were observed in all analyzed Baltic samples. The highest {sup 241}Pu concentrations in fish were found in Perciformes: benthic round goby (0.863 {+-} 0.066 mBq/g ww) and pelagic perch (0.666 {+-} 0.001 mBq/g ww). Plutonium is also non-uniformly distributed in the organs and tissues of the analyzed fish; especially pelagic herring and cod as well as benthic flounder. Most of {sup 241}Pu in flounder, herring and cod is located in soft tissues, especially digestive organs (stomach, intestine, liver). The annual individual effective doses calculated on the basis of {sup 241}Pu concentrations in fish indicated that the impact of the consumption of {sup 241}Pu containing Baltic fish on the annual effective dose for a statistical inhabitant of Poland was very small. (orig.)

  20. Detection of the spatiotemporal trends of mercury in Lake Erie fish communities: a Bayesian approach.

    Science.gov (United States)

    Azim, M Ekram; Kumarappah, Ananthavalli; Bhavsar, Satyendra P; Backus, Sean M; Arhonditsis, George

    2011-03-15

    The temporal trends of total mercury (THg) in four fish species in Lake Erie were evaluated based on 35 years of fish contaminant data. Our Bayesian statistical approach consists of three steps aiming to address different questions. First, we used the exponential and mixed-order decay models to assess the declining rates in four intensively sampled fish species, i.e., walleye (Stizostedion vitreum), yellow perch (Perca flavescens), smallmouth bass (Micropterus dolomieui), and white bass (Morone chrysops). Because the two models postulate monotonic decrease of the THg levels, we included first- and second-order random walk terms in our statistical formulations to accommodate nonmonotonic patterns in the data time series. Our analysis identified a recent increase in the THg concentrations, particularly after the mid-1990s. In the second step, we used double exponential models to quantify the relative magnitude of the THg trends depending on the type of data used (skinless-boneless fillet versus whole fish data) and the fish species examined. The observed THg concentrations were significantly higher in skinless boneless fillet than in whole fish portions, while the whole fish portions of walleye exhibited faster decline rates and slower rates of increase relative to the skinless boneless fillet data. Our analysis also shows lower decline rates and higher rates of increase in walleye relative to the other three fish species examined. The food web structural shifts induced by the invasive species (dreissenid mussels and round goby) may be associated with the recent THg trends in Lake Erie fish.