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Sample records for hyalella castroi crustacea

  1. Pairing and reproductive success in two sympatric species of Hyalella (Crustacea, Amphipoda, Dogielinotidae) from southern Brazil

    Science.gov (United States)

    da Silva Castiglioni, Daniela; Bond-Buckup, Georgina

    2008-01-01

    This study aimed at characterizing pairing and reproductive success in relation to male and female sizes of the sympatric freshwater gammarideans Hyalella pleoacuta and H. castroi from southern Brazil. These amphipods exhibit precopulatory mate guarding, in which a male will carry a potential mate beneath its ventral surface, guarding the female for several days until it molts and lays its eggs. The specimens were collected monthly with nets, from November 2003 to July 2004 in two trout aquaculture ponds at Sítio Vale das Trutas locality, São José dos Ausentes County, southern Brazil. The precopulatory pairs and ovigerous females were identified and separated in the field. In the laboratory, they were measured (cephalothorax length in mm), using a micrometer eyepiece in a stereoscopic microscope. Pairing success was estimated from the proportion of mating males and females related to their respective non-pairing individuals by size classes. Reproductive success was estimated from egg production. The mean cephalothorax length of paired males was larger than that of the unpaired males. For females, however, body size not affect pairing success for either species, because mean cephalothorax length of paired females did not differ significantly from unpaired females. Paired and unpaired males of both species of Hyalella were larger than the females. Positive assortative mating by size was observed in both species; i.e., larger males tended to pair with larger females. Male pairing success increased sharply with size. In both species, reproductive success in males increased with body size; however, the females of intermediate size classes showed greater reproductive success. This result supports the hypothesis that loading constraints play a part in structuring size-assortative pairing in these species.

  2. The first hypothelminorheic Crustacea (Amphipoda, Dogielinotidae, Hyalella from South America

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    Stella Rodrigues

    2012-11-01

    Full Text Available Most of known troglobiotic species occur in caves and subterranean environments from great depths. However, recently more attention has been given to other subterranean environments, such as the hypothelminorheic habitats. It comprises the most superficial among all subterranean habitats. This kind of environment is characterized by the constant presence of wet spots, absence of light and very particular abiotic characteristics, comprising unique species. The first hypothelminorheic Amphipoda from South America is here described, a new species of the genus Hyalella which occurs in a wetland on Southern Brazil. The new species differs from other troglobiotics of the genus by the presence of a curved seta on the inner ramus of uropod 1 and elongation of appendices, as the first pair of antennae and peraeopods 6 and 7. However, human impacts in the area where the new species occurs have changed heavily their habitat, which may have led the species to a critical level of threat or even extinction, demonstrating the fragility of this environment.a

  3. Redescription of the freshwater amphipod Hyalella faxoni from Costa Rica (Crustacea: Amphipoda: Hyalellidae

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    Exequiel R. González

    2002-06-01

    Full Text Available Hyalella faxoni Stebbing, 1903 from Costa Rica is redescribed. The species was previously in the synonymy of Hyalella azteca (Saussure, 1858. The morphological differences between these two species are discussedLa especie Hyalella faxoni Stebbing, 1903 de Costa Rica es redescrita. Esta especie estaba previamente en la sinonimia de Hyalella azteca (Saussure, 1858. Se discuten en este trabajo las diferencias morfológicas entre las dos especies

  4. A new species of Hyalella (Crustacea, Amphipoda, Dogielinotidae) from the Atlantic Forest of Misiones, Argentina

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    Colla, María Florencia; César, Inés Irma

    2015-01-01

    Abstract The freshwater genus Hyalella Smith, 1874 has a distribution restricted to the Western Hemisphere with most species being found in South America. In this report we describe a new species of Hyalella from the Atlantic Forest of the Misiones province, Argentina. PMID:25685030

  5. A new species of Hyalella (Crustacea, Amphipoda, Dogielinotidae) from the Atlantic Forest of Misiones, Argentina.

    Science.gov (United States)

    Colla, María Florencia; César, Inés Irma

    2015-01-01

    The freshwater genus Hyalella Smith, 1874 has a distribution restricted to the Western Hemisphere with most species being found in South America. In this report we describe a new species of Hyalella from the Atlantic Forest of the Misiones province, Argentina.

  6. Spatial patterns of Pisidium chilense (Mollusca Bivalvia and Hyalella patagonica (Crustacea, Amphipoda in an unpolluted stream in Navarino island (54° S, Cape Horn Biosphere Reserve

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    Patricio De Los Ríos Escalante

    2017-01-01

    Full Text Available The southern South American inland waters have many endemic species and some of them are considered as endangered for IUCN, that inhabits in unpolluted ecosystems, one of these ecosystems are the sub-Antarctic perennial forests located in the Cape Horn Biosphere Reserve at 54° S. The aim of the present study is to analyze the spatial patterns of Pisidium chilense Ituarte, 1999 (Mollusca Bivalvia and Hyalella patagonica (Cunningham, 1871 (Crustacea, Amphipoda in an unpolluted stream. Both species had aggregated spatial distribution, both have a negative binomial distribution pattern, and both are associated. The present results would agree with similar patterns in Patagonian rivers where both species coexist.

  7. Revisión de la distribución de Hyalella Smith, 1874 (Crustacea, Amphipoda en la Patagonia e islas adyacentes Revision of the distribution of Hyalella Smith, 1874 (Crustacea, Amphipoda in Patagonia and adjacent islands

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    Patricio De los Ríos-Escalante

    2012-07-01

    Full Text Available Se realiza una revisión de las especies de anfípodos del género Hyalella en aguas continentales de la Patagonia, isla Tierra del Fuego, Reserva de la Biosfera de Cabo de Hornos e islas adyacentes (38-54°S. Esta zona austral presenta numerosos tipos de ambientes acuáticos continentales como lagos, humedales y arroyos, y las principales especies en ambientes bentónicos corresponden a anfípodos del género Hyalella. La bibliografía menciona la presencia de H. costera, H. chiloensis, H. falklandensis, H. franciscae, H. neonoma, H. patagónica, H. rionegrina y H. simplex. La distribución de estas especies concuerda con estudios biogeográficos sobre la presencia de especies endémicas y de amplia distribución en el sur de la Patagonia y zona subantárticas. A pesar de la presencia de especies depredadoras introducidas, sobre la base de la literatura, los anfípodos serían más abundantes debido a la presencia de materia orgánica particulada.This study reviews the amphipod species of the genus Hyalella in the inland waters of Patagonia, Tierra del Fuego Island, Cape Horn Biosphere Reserve, and adjacent islands (38-54°S. This southern zone has numerous kinds of continental water bodies such as lakes, wetlands, and streams, and the main species in benthic assemblages are amphipods of the genus Hyalella. The literature mentions the presence of H. costera, H. chiloensis, H. falklaidensis, H. franciscae, H. neonoma, H. patagonica, H. rionegrina, and H. simplex. The distribution of these species agrees with biogeographical studies about the presence of widespread, endemic species in southern Patagonia and the sub-Antarctic zone. In spite of the presence of introduced predatory species, the literature indicates that the amphipods are more abundant due to the presence of particulated organic matter.

  8. Rineloricaria castroi, a new species of Mailed Catfish from Rio Trombetas, Brazil (Pisces, Siluriformes, Loricariidae)

    NARCIS (Netherlands)

    Isbrücker, I.J.H.; Nijssen, H.

    1984-01-01

    Rineloricaria castroi n. sp. from Rio Trombetas, Est. Pará, Brazil, is described and illustrated. It is compared with R. phoxocephala (Eigenmann & Eigenmann, 1889) from Rio Amazonas at Coari, Est. Amazonas, Brazil, which species is here illustrated for the first time.

  9. Enkele interessante Nederlandse crustacea

    NARCIS (Netherlands)

    Holthuis, L.B.

    1969-01-01

    In de laatste jaren heeft het Rijksmuseum van Natuurlijke Historie enkele vermeldenswaardige Crustacea ontvangen, die uit de Nederlandse wateren en uit de zuidelijke Noordzee afkomstig zijn. Twee van deze bleken tot soorten te behoren die nog niet eerder uit ons land vermeld waren, te weten de

  10. Reduced metals concentrations of water, sediment and hyalella azteca from lakes in the vicinity of the sudbury metal smelters, Ontario, Canada.

    Science.gov (United States)

    Shuhaimi-Othman, M; Pascoe, D; Borgmann, U; Norwood, W P

    2006-06-01

    Hyalella azteca (Crustacea: Amphipoda), water and sediments from 12 circum-neutral lakes between Sudbury and North Bay in Ontario, Canada were sampled in August 1998 and analyzed for 10 metals including Cu, Zn, Cd, Ni, Pb, Co, Mo, V, Ba and Ti. Statistical analyses showed that concentrations of the metals in H. azteca, water and sediment differed significantly (ANOVA, Pazteca and Mo in water). There was a trend of declining metal concentration, especially for Cu, Ni and Co (in water, Hyalella and sediment), with distance from the smelters indicating the reduced impact of atmospheric pollution. Metal concentrations of lakes (water) in the Sudbury area were found to be lower compared to data from the 1970s and 1980s indicating an improvement in water quality. Metal concentrations in field-collected amphipods compared favorably with those measured in the laboratory in animals exposed to deep-water sediments, provided metal concentrations were not extremely low (e.g., Pb) and that water chemistry differences (e.g., pH) were taken into account for some metals (especially Cd). In general bioaccumulation of metals in H. azteca was predicted better from surface water than from sediment total metal.

  11. The Crustacea Decapoda of Cyprus

    NARCIS (Netherlands)

    Lewinsohn, Ch.; Holthuis, L.B.

    1986-01-01

    An account of the species of Crustacea Decapoda so far known from Cyprus, based on (1) material collected during the 1967-1970 Hebrew University - Smithsonian Institution Joint Program "Biota of the Red Sea and the Eastern Mediterranean", (2) Cyprus material from other sources, and (3) published rec

  12. A new species of freshwater amphipod (Dogielinotidae, Hyalella from Southeastern Brazil

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    Rafaela Bastos-Pereira

    Full Text Available To the present 57 species of Hyalella were described for Americas, 15 of them found in Brazil, which is among the most diverse countries for this genus. This work aims to describe a new Hyalella species with benthic habits which is found in a water source on Southeastern Brazil. It is mainly characterized by a wide truncated process formed near the dactylus insertion on gnathopod 2, besides both coxal and sternall gills present on pereonits 2 to 7. This work improves the knowledge on biodiversity about Hyalella species.

  13. Modifying Foods and Feeding Regimes to Optimize the Performance of Hyalella azteca during Chronic Toxicity Tests

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    The amphipod Hyalella azteca is commonly used to assess the toxicity of sediments and waters. However, laboratories have reported varying success in maintaining healthy cultures and in obtaining consistent growth and reproduction (where applicable), especially during tests...

  14. Modifying Foods and Feeding Regimes to Optimize the Performance of Hyalella azteca during Chronic Toxicity Tests

    Science.gov (United States)

    The amphipod Hyalella azteca is commonly used to assess the toxicity of sediments and waters. However, laboratories have reported varying success in maintaining healthy cultures and in obtaining consistent growth and reproduction (where applicable), especially during tests...

  15. Reduced recruitment in Hyalella azteca (Saussure, 1858) exposed to copper.

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    Othman, M Shuhaimi; Pascoe, David

    2002-09-01

    Neonates of the amphipod Hyalella azteca were exposed for a 35-day period in the laboratory to a range of copper concentrations, nominally 18 microg/l, 40 microg/l, 70 microg/l and 260 microg/l. The reproductive status of the population was assessed by recording recruitment, the number of precopulatory pairs and number of gravid females. At the end of the experiment, the body lengths of individuals were measured using image analysis. There was a significant decrease in the final population size of H. azteca with increasing copper concentration and compared with the control. Copper significantly reduced recruitment of juveniles and length composition of the final population and there was also a trend toward reduced precopula number with increasing copper concentrations.

  16. Responses of Hyalella azteca to acute and chronic microplastic exposures.

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    Au, Sarah Y; Bruce, Terri F; Bridges, William C; Klaine, Stephen J

    2015-11-01

    Limited information is available on the presence of microplastics in freshwater systems, and even less is known about the toxicological implications of the exposure of aquatic organisms to plastic particles. The present study was conducted to evaluate the effects of microplastic ingestion on the freshwater amphipod, Hyalella azteca. Hyalella azteca was exposed to fluorescent polyethylene microplastic particles and polypropylene microplastic fibers in individual 250-mL chambers to determine 10-d mortality. In acute bioassays, polypropylene microplastic fibers were significantly more toxic than polyethylene microplastic particles; 10-d lethal concentration 50% values for polyethylene microplastic particles and polypropylene microplastic fibers were 4.64 × 10(4) microplastics/mL and 71.43 microplastics/mL, respectively. A 42-d chronic bioassay using polyethylene microplastic particles was conducted to quantify effects on reproduction, growth, and egestion. Chronic exposure to polyethylene microplastic particles significantly decreased growth and reproduction at the low and intermediate exposure concentrations. During acute exposures to polyethylene microplastic particles, the egestion times did not significantly differ from the egestion of normal food materials in the control; egestion times for polypropylene microplastic fibers were significantly slower than the egestion of food materials in the control. Amphipods exposed to polypropylene microplastic fibers also had significantly less growth. The greater toxicity of microplastic fibers than microplastic particles corresponded with longer residence times for the fibers in the gut. The difference in residence time might have affected the ability to process food, resulting in an energetic effect reflected in sublethal endpoints.

  17. Acute toxicity of pyraclostrobin and trifloxystrobin to Hyalella azteca.

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    Morrison, Shane A; McMurry, Scott T; Smith, Loren M; Belden, Jason B

    2013-07-01

    Fungicide application rates on row crop agriculture have increased across the United States, and subsequently, contamination of adjacent wetlands can occur through spray drift or field runoff. To investigate fungicide toxicity, Hyalella azteca amphipods were exposed to 2 fungicide formulations, Headline and Stratego, and their active strobilurin ingredients, pyraclostrobin and trifloxystrobin. Water-only exposures resulted in similar median lethal concentration (LC50; 20-25 µg/L) values for formulations and strobilurin ingredients, suggesting that toxicity is due to strobilurin ingredients. These values were below concentrations that could occur following spray drift over embedded cropland wetlands. When fungicides were added to overlying water of sediment-water microcosms, toxicity was reduced by 500% for Headline and 160% for Stratego, compared with water-only exposures, based on the total amount of fungicide added to the systems. In addition, when fungicides were added to sediment prior to the addition of water, the reduction in toxicity was even greater, with no toxicity occurring at environmentally relevant levels. Differences in toxicity among exposure groups were explained by dissipation from water as toxicity values based on measured water concentrations were within 20% between all systems. The present study reinforces previous studies that Headline and Stratego are toxic to nontarget aquatic organisms. However, the presence of sediment is likely to ameliorate some toxicity of fungicide formulations, especially if spraying occurs prior to wetland inundation.

  18. Naamlijst van de Nederlandse landpissebedden (Crustacea: Isopoda: Oniscidea)

    NARCIS (Netherlands)

    Berg, M.P.

    1997-01-01

    Checklist of Dutch woodlice (Crustacea: Isopoda: Oniscidea). An updated checklist for the terrestrial isopods of The Netherlands is presented. Four species, Armadillo officinalis, Eluma purpurascens, Miktoniscus patiencei, and Trichoniscoides sarsi are new to the woodlice fauna of The Netherlands co

  19. DIFFERENTIAL DISPLAY ANALYSES OF THE AMPHIPOD HYALELLA AZTECA EXPOSED TO ETHYNYLESTRADIOL AT THREE DIFFERENT TROPHIC LEVELS

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    A study was conducted to determine if differential display could be used to detect differences in gene expression in the amphipod, Hyalella azteca. In a study of synthetic estrogen attenuation in different aquatic media, amphipods were exposed to 20 ng/L 17 a-ethynylestradiol in...

  20. Role of vegetation in a constructed wetland on nutrient-pesticide mixture toxicity of Hyalella azteca

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    The toxicity of a nutrient-pesticide mixture in non-vegetated and vegetated sections of a constructed wetland (60 X 30 X 0.3 m) was assessed using Hyalella azteca 48 h aqueous whole effluent toxicity bioassays. Both sections were amended with a mixture of sodium nitrate, triple super phosphate, dia...

  1. Responses of phytoplankton and Hyalella azteca to agrichemical mixtures in a constructed wetland mesocosms

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    We assessed the capability of a constructed wetland to mitigate toxicity of a variety of possible mixtures such as nutrients only (N, P), pesticides only (atrazine, S-metolachlor, permethrin), and nutrients+pesticides on phytoplankton chlorophyll a, 48 h aqueous Hyalella azteca survival, and 10 d se...

  2. Hyalella azteca Responses to Coldwater River Backwater Sediments in Mississippi, USA

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    Sediment from three Coldwater River, Mississippi backwaters was examined using 28 d Hyalella azteca bioassays and chemical analyses for 33 pesticides, 7 metals and 7 PCBs. Hydrologic connectivity between the main river channel and backwater varied widely among the three sites. Mortality occurred i...

  3. Effect on Hyalella azteca after pulse exposure to environmentally realistic concentrations of permethrin

    DEFF Research Database (Denmark)

    Pedersen, Signe; Palmqvist, Annemette; Forbes, Valery E.

    realistic pulse exposure and concentration of a pyrethroid pesticide, permethrin, on the freshwater amphipod Hyalella azteca. Permethrin is a pyrethroid insecticide used in mosquito control and to control a wide range of insect pests on various crops and is known to be highly toxic to aquatic invertebrates...

  4. Efficiency of experimental rice (Oryza sativa L.) fields in mitigating diazinon runoff toxicity to Hyalella azteca

    Science.gov (United States)

    This study assessed the viability of using planted, mature rice fields in mitigating diazinon (an organophosphate insecticide) runoff toxicity using aqueous 48 h Hyalella azteca whole effluent toxicity bioassays. Rice fields decreased diazinon concentrations 80.1-99.9% compared with 10.8% in the unv...

  5. DIFFERENTIAL DISPLAY ANALYSES OF THE AMPHIPOD HYALELLA AZTECA EXPOSED TO ETHYNYLESTRADIOL AT THREE DIFFERENT TROPHIC LEVELS

    Science.gov (United States)

    A study was conducted to determine if differential display could be used to detect differences in gene expression in the amphipod, Hyalella azteca. In a study of synthetic estrogen attenuation in different aquatic media, amphipods were exposed to 20 ng/L 17 a-ethynylestradiol in...

  6. REPRODUCTIVE TOXICITY OF CHLORPYRIFOS, DIELDRIN, AND METHYL MERCURY MIXTURES TO THE AMPHIPOD, HYALELLA AZTECA

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    Toxicological interactions were assessed on the reproduction of the amphipod Hyalella azteca throughout a chronic exposure to methyl mercury (0.9, 4.7, 23.3 nM), chlorpyrifos (0.01, 0.05, 0.24), dieldrin (0.5, 2.3, 11.4 nM) and their binary mixtures. H. azteca were exposed to the...

  7. Toxicity of a cadmium-contaminated diet to Hyalella azteca.

    Science.gov (United States)

    Ball, Angela L; Borgmann, Uwe; Dixon, D George

    2006-09-01

    Four- and 10-week chronic toxicity tests were conducted using the freshwater amphipod Hyalella azteca and Cd-contaminated Chlorella sp. as a food source. Chlorella sp. was cultured in various Cd concentrations, filtered from solution, rinsed, dried, and ground into food flakes for the H. azteca. Unlike Cd toxicity from water sources, growth was found to be a more sensitive toxicological endpoint than survival, with calculated 50 and 25% effect concentrations (EC50s and EC25s, respectively) of 5.43 and 2.82 nmol/g, respectively, for Cd measured in food. Based on the regression of Cd in Chlorella sp. against Cd in filtered culture medium, the EC50 and EC25 corresponded to dissolved Cd concentrations of 11.30 and 5.09 nmol/L, respectively. Little or no bioaccumulation of Cd was found in the tissues of H. azteca that were fed contaminated food. These results demonstrate an apparent toxicological effect (either direct or indirect) of Cd-contaminated Chlorella sp. to H. azteca that is not associated with Cd accumulation. Toxicity of Cd-contaminated Chlorella sp. differs from waterborne Cd toxicity both in terms of the most sensitive endpoint (growth vs survival) and the relationship between toxicity and bioaccumulation. Unlike Cd toxicity through water exposure, Cd bioaccumulation by H. azteca cannot, therefore, be used to infer toxicity of Cd in a diet of Chlorella sp. Although the concentration of Cd in the algal culture medium that ultimately reduced growth of H. azteca in the present study was higher than Cd in water, which caused mortality to H. azteca in water-only tests during previous studies, further research regarding the contribution of dietary Cd to overall Cd toxicity is needed to verify that water-quality guidelines and risk assessments based on water-only exposures are fully protective.

  8. Toxicity of manganese to Ceriodaphnia dubia and Hyalella azteca

    Science.gov (United States)

    Lasier, P.J.; Winger, P.V.; Bogenrieder, K.J.

    2000-01-01

    Manganese is a toxic element frequently overlooked when assessing toxicity of effluents, sediments and pore waters. Manganese can be present at toxic levels in anoxic solutions due to its increased solubility under chemically-reducing conditions, and it can remain at those levels for days in aerated test waters due to slow precipitation kinetics. Ceriodaphnia dubia and Hyalella azteca are freshwater organisms often used for toxicity testing and recommended for assessments of effluents and pore waters. Lethal and reproductive-inhibition concentrations of Mn were determined for C. dubia in acute 48h tests and chronic 3-brood tests using animals Manganese concentrations were measured analytically at test initiation and after 96 h for calculations of toxicity endpoints and determinations of Mn precipitation during the tests. Minimal amounts of Mn (below 3%) precipitated within 96 h. LC50s determined for H. azteca progressively increased from 3.0 to 8.6 to 13.7 mg Mn/L in soft, moderately-hard and hard waters, respectively. The tolerance of C. dubia to Mn was not significantly different between moderately-hard and hard waters, but was significantly lower in soft water. There was no significant difference in Mn sensitivity between the ages of C. dubia tested. Acute LC50 values for C. dubia averaged 6.2, 14.5 and 15.2 mg Mn/L and chronic IC50 values averaged 3.9, 8.5 and 11.5 mg Mn/L for soft, moderately-hard and hard waters, respectively. Manganese toxicity should be considered when assessing solutions with concentrations near these levels.

  9. Toxicity and transcriptomic analysis in Hyalella azteca suggests increased exposure and susceptibility of epibenthic organisms to Zinc Oxide Nanoparticles.

    Science.gov (United States)

    Nanoparticles (NPs) are expected to make their way into the aquatic environment where sedimentation of particles will likely occur, putting benthic organisms at particular risk. Therefore, organisms such as Hyalella azteca, an epibenthic crustacean which forages at the sediment ...

  10. Toxicity and transcriptomic analysis in Hyalella azteca suggests increased exposure and susceptibility of epibenthic organisms to Zinc Oxide Nanoparticles.

    Science.gov (United States)

    Nanoparticles (NPs) are expected to make their way into the aquatic environment where sedimentation of particles will likely occur, putting benthic organisms at particular risk. Therefore, organisms such as Hyalella azteca, an epibenthic crustacean which forages at the sediment ...

  11. TOXICOKINETIC INTERACTIONS AND SURVIVAL OF HYALELLA AZTECA EXPOSED TO BINARY MIXTURES OF CHLORPYRIFOS, DIELDRIN, AND METHYL MERCURY

    Science.gov (United States)

    Chemical mixture interactions of chlorpyrifos, dieldrin, and methyl mercury were evaluated in Hyalella azteca. Survival of adult and juvenile organisms was evaluated following exposure to individual chemicals and in binary combinations. Binary interactions of the model chemicals...

  12. Effect of diet quality on chronic toxicity of aqueous lead to the amphipod Hyalella azteca.

    Science.gov (United States)

    Besser, John M; Ivey, Chris D; Brumbaugh, William G; Ingersoll, Christopher G

    2016-07-01

    The authors investigated the chronic toxicity of aqueous Pb to the amphipod Hyalella azteca (Hyalella) in 42-d tests using 2 different diets: 1) the yeast + cereal leaf + trout pellet (YCT) diet, fed at the uniform low ration used in standard methods for sediment toxicity tests; and 2) a new diet of diatoms + TetraMin flakes (DT), fed at increasing rations over time, that has been optimized for use in Hyalella water-only tests. Test endpoints included survival, weight, biomass, fecundity, and total young. Lethal effects of Pb were similar for the DT and YCT tests (20% lethal concentration [LC20] = 13 μg/L and 15 μg/L, respectively, as filterable Pb). In contrast, weight and fecundity endpoints were not significantly affected in the DT test at Pb concentrations up to 63 µg/L, but these endpoints were significantly reduced by Pb in the YCT test-and in a 2005 test in the same laboratory with a diet of conditioned Rabbit Chow (RC-2005). The fecundity and total young endpoints from the YCT and RC-2005 tests were considered unreliable because fecundity in controls did not meet test acceptability criteria, but both of these tests still produced lower Pb effect concentrations (for weight or biomass) than the test with the DT diet. The lowest biotic ligand model-normalized effect concentrations for the 3 tests ranged from 3.7 μg/L (weight 20% effect concentration [EC20] for the RC-2005 test) to 8.2 μg/L (total young EC20 for the DT test), values that would rank Hyalella as the second or third most sensitive of 13 genera in a species sensitivity distribution for chronic Pb toxicity. These results demonstrate that toxicity tests with Hyalella fed optimal diets can meet more stringent test acceptability criteria for control performance, but suggest that results of these tests may underestimate sublethal toxic effects of Pb to Hyalella under suboptimal feeding regimes. Environ Toxicol Chem 2016;35:1825-1834. Published 2015 Wiley Periodicals Inc

  13. Effect of diet quality on chronic toxicity of aqueous lead to the amphipod Hyalella azteca

    Science.gov (United States)

    Besser, John M.; Ivey, Chris D.; Brumbaugh, William G.; Ingersoll, Christopher G.

    2016-01-01

    The authors investigated the chronic toxicity of aqueous Pb to the amphipod Hyalella azteca (Hyalella) in 42-d tests using 2 different diets: 1) the yeastþcereal leafþtrout pellet (YCT) diet, fed at the uniform low ration used in standard methods for sediment toxicity tests; and 2) a new diet of diatomsþTetraMin flakes (DT), fed at increasing rations over time, that has been optimized for use in Hyalella water-only tests. Test endpoints included survival, weight, biomass, fecundity, and total young. Lethal effects of Pb were similar for the DT and YCT tests (20% lethal concentration [LC20]¼13 mg/L and 15mg/L, respectively, as filterable Pb). In contrast, weight and fecundity endpoints were not significantly affected in the DT test at Pb concentrations up to 63 mg/L, but these endpoints were significantly reduced by Pb in the YCT test—and in a 2005 test in the same laboratory with a diet of conditioned Rabbit Chow (RC-2005). The fecundity and total young endpoints from the YCT and RC-2005 tests were considered unreliable because fecundity in controls did not meet test acceptability criteria, but both of these tests still produced lower Pb effect concentrations (for weight or biomass) than the test with the DT diet. The lowest biotic ligand model–normalized effect concentrations for the 3 tests ranged from 3.7mg/L (weight 20% effect concentration [EC20] for the RC-2005 test) to 8.2 mg/L (total young EC20 for the DT test), values that would rank Hyalella as the second or third most sensitive of 13 genera in a species sensitivity distribution for chronic Pb toxicity. These results demonstrate that toxicity tests with Hyalella fed optimal diets can meet more stringent test acceptability criteria for control performance, but suggest that results of these tests may underestimate sublethal toxic effects of Pb to Hyalella under suboptimal feeding regimes.

  14. Saturation models of arsenic, cobalt, chromium and manganese bioaccumulation by Hyalella azteca.

    Science.gov (United States)

    Norwood, W P; Borgmann, U; Dixon, D G

    2006-10-01

    Bioaccumulation of As, Co, Cr and Mn by the benthic amphipod Hyalella azteca in Burlington City tap (Lake Ontario) water was measured in 4-week tests. Bioaccumulation increased with exposure concentration and demonstrated an excellent fit to a saturation model (r(2): 0.819, 0.838, 0.895 and 0.964 for As, Co, Cr and Mn, respectively). The proportion of total body Mn eliminated during a 24-h depuration period decreased as Mn body concentration increased, apparently due to a saturation of the elimination rate. The high maximum body concentration of 116,000 nmol g(-1) appears to result from the saturation of the Mn excretion which is slightly greater than the maximum Mn uptake rate. Elimination rates for As, Co and Cr were not dependent on body concentration. The four elements were not physiologically regulated in Hyalella. Their body concentrations should be good indicators of bioavailability and useful for environmental assessment.

  15. Acute dysprosium toxicity to Daphnia pulex and Hyalella azteca and development of the biotic ligand approach.

    Science.gov (United States)

    Vukov, Oliver; Smith, D Scott; McGeer, James C

    2016-01-01

    The toxicological understanding of rare earth elements (REEs) in the aquatic environment is very limited but of increasing concern. The objective of this research is to compare the toxicological effect of the REE dysprosium to the freshwater invertebrates Daphnia pulex and Hyalella azteca and in the more sensitive organism, understand the toxicity modifying influence of Ca, Na, Mg, pH and dissolved organic matter (DOM). Standard methods (Environment Canada) were followed for testing and culture in media of intermediate hardness (60mg CaCO3 mg/L) at pH 7.8 with Ca at 0.5, Na 0.5, Mg 0.125 (mM) and 23°C. Acute toxicity tests were done with azteca and D. pulex revealed Hyalella to be 1.4 times more sensitive than Daphnia. Additions of Ca and Na but not Mg provided significant protection against Dy toxicity to Hyalella. Similarly, low pH was associated with reduction in toxicity. Exposures which were pH buffered with and without MOPS were significantly different and indicated that MOPS enhanced Dy toxicity. DOM also mitigated Dy toxicity. Biotic ligand based parameters (LogK values) were calculated based on free ion relationships as determined by geochemical equilibrium modeling software (WHAM ver. 7.02). The logK value for Dy(3+) toxicity to Hyalella was 7.75 while the protective influence of Ca and Na were 3.95 and 4.10, respectively. This study contributes data towards the development of site specific water quality guidelines and criteria for Dy and possibly REEs in general and offers insight into the complex bio-geochemical nature of this element.

  16. Evaluation of toxicity: Whole-sediment versus overlying-water exposures with amphipod Hyalella azteca

    Science.gov (United States)

    Ingersoll, C.G.; Ivey, C.D.; Brunson, E.L.; Hardesty, D.K.; Kemble, N.E.

    2000-01-01

    A laboratory study was conducted to evaluate the toxicity of whole-sediment versus overlying-water exposures to the amphipod Hyalella azteca using field-collected sediments. Severe toxic effects (5-63% survival) were observed with amphipods exposed for 10 d in direct contact with sediment. In contrast, amphipods exposed only to overlying water in these sediment exposures did not exhibit any toxic effects.

  17. Influence of bromide on the performance of the amphipod Hyalella azteca in reconstituted waters

    Science.gov (United States)

    Ivey, Chris D.; Ingersoll, Christopher G.

    2016-01-01

    Poor performance of the amphipod Hyalella azteca has been observed in exposures using reconstituted waters. Previous studies have reported success in H. azteca water-only exposures with the addition of relatively high concentrations of bromide. The present study evaluated the influence of lower environmentally representative concentrations of bromide on the response ofH. azteca in 42-d water-only exposures. Improved performance of H. azteca was observed in reconstituted waters with >0.02 mg Br/L.

  18. Saturation models of arsenic, cobalt, chromium and manganese bioaccumulation by Hyalella azteca

    Energy Technology Data Exchange (ETDEWEB)

    Norwood, W.P. [Department of Biology, University of Waterloo, Waterloo, ON N2L 3G1 (Canada) and Aquatic Ecosystems Protection Research Branch, National Water Research Institute, Environment Canada, P.O. Box 5050, Burlington, ON L7R 4A6 (Canada)]. E-mail: warren.norwood@ec.gc.ca; Borgmann, U. [Aquatic Ecosystems Protection Research Branch, National Water Research Institute, Environment Canada, P.O. Box 5050, Burlington, ON L7R 4A6 (Canada); Dixon, D.G. [Department of Biology, University of Waterloo, Waterloo, ON N2L 3G1 (Canada)

    2006-10-15

    Bioaccumulation of As, Co, Cr and Mn by the benthic amphipod Hyalella azteca in Burlington City tap (Lake Ontario) water was measured in 4-week tests. Bioaccumulation increased with exposure concentration and demonstrated an excellent fit to a saturation model (r {sup 2}: 0.819, 0.838, 0.895 and 0.964 for As, Co, Cr and Mn, respectively). The proportion of total body Mn eliminated during a 24-h depuration period decreased as Mn body concentration increased, apparently due to a saturation of the elimination rate. The high maximum body concentration of 116,000 nmol g{sup -1} appears to result from the saturation of the Mn excretion which is slightly greater than the maximum Mn uptake rate. Elimination rates for As, Co and Cr were not dependent on body concentration. The four elements were not physiologically regulated in Hyalella. Their body concentrations should be good indicators of bioavailability and useful for environmental assessment. - Bioaccumulation of As, Co, Cr and Mn follow a saturation model in Hyalella azteca and can be useful for environmental assessment.

  19. Optimizing the performance of the amphipod, Hyalella azteca, in chronic toxicity tests: Results of feeding studies with various foods and feeding regimes

    Science.gov (United States)

    The freshwater amphipod, Hyalella azteca, is a common organism used for sediment toxicity testing. Standard methods for 10-d and 42-d sediment toxicity tests with H. azteca were last revised and published by USEPA/ASTM in 2000. While Hyalella azteca methods exist for sediment tox...

  20. Optimizing the performance of the amphipod, Hyalella azteca, in chronic toxicity tests: Results of feeding studies with various foods and feeding regimes

    Science.gov (United States)

    The freshwater amphipod, Hyalella azteca, is a common organism used for sediment toxicity testing. Standard methods for 10-d and 42-d sediment toxicity tests with H. azteca were last revised and published by USEPA/ASTM in 2000. While Hyalella azteca methods exist for sediment tox...

  1. Acute dysprosium toxicity to Daphnia pulex and Hyalella azteca and development of the biotic ligand approach

    Energy Technology Data Exchange (ETDEWEB)

    Vukov, Oliver, E-mail: vuko3930@mylaurier.ca [Biology Department, Wilfrid Laurier University, Waterloo, Ontario N2L 3C5 (Canada); Smith, D. Scott [Chemistry Department, Wilfrid Laurier University, Waterloo, Ontario N2L 3C5 (Canada); McGeer, James C. [Biology Department, Wilfrid Laurier University, Waterloo, Ontario N2L 3C5 (Canada)

    2016-01-15

    The toxicological understanding of rare earth elements (REEs) in the aquatic environment is very limited but of increasing concern. The objective of this research is to compare the toxicological effect of the REE dysprosium to the freshwater invertebrates Daphnia pulex and Hyalella azteca and in the more sensitive organism, understand the toxicity modifying influence of Ca, Na, Mg, pH and dissolved organic matter (DOM). Standard methods (Environment Canada) were followed for testing and culture in media of intermediate hardness (60 mg CaCO{sub 3} mg/L) at pH 7.8 with Ca at 0.5, Na 0.5, Mg 0.125 (mM) and 23 °C. Acute toxicity tests were done with <24 h old neonates for 48 h in the case of D. pulex and with 2–9 days old offspring for 96 h tests with Hyalella. The potential protective effect of cationic competition was tested with Ca (0.5–2.0 mM), Na (0.5–2.0 mM) and Mg (0.125–0.5 mM). The effect of pH (6.5–8.0) and Suwannee River DOM complexation (at dissolved organic carbon (DOC) concentrations of 9 and 13 mg C/L) were evaluated. Dissolved Dy concentrations were lower than total (unfiltered) indicating precipitation, particularly at higher concentrations. Acute toxicity of Dy to H. azteca and D. pulex revealed Hyalella to be 1.4 times more sensitive than Daphnia. Additions of Ca and Na but not Mg provided significant protection against Dy toxicity to Hyalella. Similarly, low pH was associated with reduction in toxicity. Exposures which were pH buffered with and without MOPS were significantly different and indicated that MOPS enhanced Dy toxicity. DOM also mitigated Dy toxicity. Biotic ligand based parameters (Log K values) were calculated based on free ion relationships as determined by geochemical equilibrium modeling software (WHAM ver. 7.02). The log K value for Dy{sup 3+} toxicity to Hyalella was 7.75 while the protective influence of Ca and Na were 3.95 and 4.10, respectively. This study contributes data towards the development of site specific

  2. Eluma purpurascens, nieuw voor de Nederlandse fauna (Crustacea: Isopoda: Oniscoidea)

    NARCIS (Netherlands)

    Tempelman, D.; Berg, M.P.

    1997-01-01

    Eluma purpurascens, new for the Dutch fauna (Crustacea: Isopoda: Oniscoidea). The first Dutch specimen of Eluma purpurascens was found on 29 April 1994 on the Kaloot, east of Vlissingen, in the south-western province of Zeeland. One year later the species proved to be locally common along the southe

  3. Landpissebedden van de Ooijpolder: deel 1. verspreiding (Crustacea: Isopoda: Oniscidea)

    NARCIS (Netherlands)

    Wijnhoven, H.

    2000-01-01

    Terrestrial isopods of the Ooijpolder: part 1. distribution (Crustacea: Isopoda: Oniscidea) The distributions and habitats of woodlice were investigated in ‘the Ooijpolder’, also named ‘the Ooij’. The area of approximately 41 square kilometers is located along the river Waal, east of Nijmegen, Provi

  4. Hyalella azteca (Saussure) responses to Coldwater River backwater sediments in Mississippi, USA.

    Science.gov (United States)

    Knight, Scott S; Lizotte, Richard E; Shields, F Douglas

    2009-10-01

    Sediment from three Coldwater River, Mississippi backwaters was examined using 28 day Hyalella azteca bioassays and chemical analyses for 33 pesticides, seven metals and seven PCB mixtures. Hydrologic connectivity between the main river channel and backwater varied widely among the three sites. Mortality occurred in the most highly connected backwater while growth impairment occurred in the other two. Precopulatory guarding behavior was not as sensitive as growth. Fourteen contaminants (seven metals, seven pesticides) were detected in sediments. Survival was associated with the organochlorine insecticide heptachlor.

  5. Optimizing the performance of Hyalella azteca in chronic toxicity tests: Results of feeding studies with various foods and feeding regimes

    Science.gov (United States)

    The freshwater amphipod Hyalella azteca is a common organism used for sediment toxicity testing in the United States and elsewhere. Standard methods for 10-d and 42-d toxicity tests with H. azteca were last revised and published by USEPA/ASTM in 2000. Under the methods in the man...

  6. Interlaboratory testing of 42-d Hyalella azteca survival, growth and reproduction method with sediment and water-only exposures

    Science.gov (United States)

    Over the past four years, USEPA-Duluth, USGS-Columbia, the Illinois Natural History Survey, and Environment Canada have conducted studies to refine the USEPA/ASTM International methods for conducting 10- to 42-d water or sediment toxicity exposures with Hyalella azteca. In advanc...

  7. Evaluation of the Influence of Bromide or Iodide on the Performance the Amphipod Hyalella azteca in Reconstituted Waters

    Science.gov (United States)

    Survival, growth, or reproduction of the amphipod Hyalella azteca (HA) is reported to be poor when some reconstituted waters have been used to conduct chronic (>14-d) water-only or sediment toxicity tests, including ASTM reconstituted hard water (with no addition of Bromi...

  8. Influence of selected water quality characteristics on the toxicity of lambda-cyhalothrin and gamma-cyhalothrin to Hyalella azteca

    Science.gov (United States)

    This study was conducted to assess the influence of suspended solids, dissolved organic carbon, and phytoplankton (as chlorophyll a) water quality characteristics on lambda-cyhalothrin and gamma-cyhalothrin aqueous toxicity to Hyalella azteca using natural water from 12 ponds and lakes in Mississipp...

  9. Evaluation of the Influence of Bromide or Iodide on the Performance the Amphipod Hyalella azteca in Reconstituted Waters

    Science.gov (United States)

    Survival, growth, or reproduction of the amphipod Hyalella azteca (HA) is reported to be poor when some reconstituted waters have been used to conduct chronic (>14-d) water-only or sediment toxicity tests, including ASTM reconstituted hard water (with no addition of Bromi...

  10. Interlaboratory testing of 42-d Hyalella azteca survival, growth and reproduction method with sediment and water-only exposures

    Science.gov (United States)

    Over the past four years, USEPA-Duluth, USGS-Columbia, the Illinois Natural History Survey, and Environment Canada have conducted studies to refine the USEPA/ASTM International methods for conducting 10- to 42-d water or sediment toxicity exposures with Hyalella azteca. In advanc...

  11. Optimizing the performance of Hyalella azteca in chronic toxicity tests: Results of feeding studies with various foods and feeding regimes

    Science.gov (United States)

    The freshwater amphipod Hyalella azteca is a common organism used for sediment toxicity testing in the United States and elsewhere. Standard methods for 10-d and 42-d toxicity tests with H. azteca were last revised and published by USEPA/ASTM in 2000. Under the methods in the man...

  12. Effects of an atrazine, metolachlor, and fipronil mixture on Hyalella azteca (Saussure) in a modified backwater wetland

    Science.gov (United States)

    We examined the toxicity mitigation efficiency of a hydrologically modified backwater wetland amended with a mixture of three pesticides, atrazine, metolachlor, and fipronil, using 96 h survival bioassays with Hyalella azteca. Significant H. azteca 96 h mortality occurred within the first two hours...

  13. The amphipod Hyalella azteca as a biomonitor in field deployment studies for metal mining

    Energy Technology Data Exchange (ETDEWEB)

    Couillard, Y. [Existing Substances Division, Science and Risk Assessment Directorate, Environment Canada, Place Vincent Massey, 351 St. Joseph Boulevard, 20th floor, Gatineau, Quebec, K1A 0H3 (Canada)], E-mail: yves.couillard@ec.gc.ca; Grapentine, L.C.; Borgmann, U. [Water Science and Technology Directorate, Environment Canada, 867 Lakeshore Road, Burlington, Ontario, L7R 4A6 (Canada); Doyle, P. [Existing Substances Division, Science and Risk Assessment Directorate, Environment Canada, Place Vincent Massey, 351 St. Joseph Boulevard, 20th floor, Gatineau, Quebec, K1A 0H3 (Canada); Masson, S. [Parc Aquarium du Quebec, 1675 avenue des Hotels, Quebec, Quebec, Canada G1W 4S3 (Canada)

    2008-12-15

    Specimens of the amphipod Hyalella azteca were deployed, in June-July 2003, along metal contamination gradients in two rivers affected by metal mining in the Abitibi - James Bay region, northwestern Quebec. The amphipods were placed along with natural food items in small, acrylic cages and left in six riverine sites for 17 days. Twelve metals (As, Cu, La, Mn, Ni, Sb, Se, Tl, U, V, Zn, and CrO{sub 4}{sup 2-} modelled by WHAM VI) in transplanted H. azteca varied along metal contamination gradients in a consistent manner, i.e., as a function of metal exposure. Bioaccumulation of As, Cr, La, Ni, Sb, Se, Tl, U and V, as defined by a field BCF, was significantly correlated with their chronic toxicity potential towards the amphipod. We conclude that H. azteca may be a useful field biomonitor for metal mining. In addition, our results suggest that such biomonitoring programs should include less studied elements such as Se in mining effluents. - Hyalella azteca accumulates dissolved metals in a dose-dependent manner.

  14. An assessment of Hyalella azteca burrowing activity under laboratory sediment toxicity testing conditions.

    Science.gov (United States)

    Doig, Lorne E; Liber, Karsten

    2010-09-01

    Burrowing of the freshwater amphipod Hyalella azteca was evaluated under laboratory conditions similar to those recommended for standard sediment toxicity testing in Canada (EPS 1/RM/33; Environment Canada, 1997) and the United States (EPA/600/R-99/064; US EPA, 2000). Sediment type, time of day (light versus dark), size of animal, and the presence or absence of food were varied to assess their effects on burrowing activity. Hyalella azteca were found to burrow rapidly in fine, organic-rich sediments, but were slower to burrow in a sandy sediment. There was no increase in the number of animals occupying the sediment surface of a fine, organic-rich sediment after 4h of darkness compared to the previous 4h of light. Over a 9- to 10-d duration, a higher percentage of animals occupied the surface of the sandy sediment. The addition of food promoted burrowing in sandy sediment, as did using smaller animals. Overall, longer-duration tests involving older animals and coarse sediments may require formal observation to confirm burrowing and ensure adequate sediment exposure. The addition of food during a test may promote the burrowing of larger animals in coarse sediments, but may not be necessary in field-collected sediments that are not excessively sandy.

  15. Intersexuality in Crustacea: an environmental issue?

    Science.gov (United States)

    Ford, Alex T

    2012-02-01

    This paper aims to give a historical overview of current understanding about intersexuality in crustaceans, assesses gaps in our knowledge and asks whether it should be an environmental concern. The oldest known cases of intersexuality come from 70 million year old fossil crabs whilst the oldest published case of intersex crustacean stems from a 1730 Royal Society report of a gynandromorph lobster. Many crustacean species are sequential hermaphroditic or simultaneous hermaphrodites. Consequently, there has been confusion as to whether accounts of intersex in the literature are correct. Intersexuality is fairly common throughout the Crustacea and it has been suggested that intersex may arise through different mechanisms. For example, sexual gynandromorphism may arise through disruption in early embryonic development whereas intersexuality may also arise through perturbations of androgenic gland hormone and sexual differentiation in later development. The causes of intersex are multifaceted and can occur through a number of mechanisms including parasitism, environmental sex determination, genetic abnormalities and increasingly pollution is being implicated. Despite many studies on the effects of endocrine disrupters on crustaceans, very few have focussed on wild populations or male related endpoints; rather many laboratory studies have been attempting to assess biomarkers of feminisation. This is surprising as many of the seminal papers on endocrine disruption focussed on effects found in the wild and male specimens. This paper argues that we might have been addressing the right questions (i.e. pollution induced intersex), but in the wrong way (feminisation); and therefore gives recommendations for future directions for research. Biomarker development has been hampered by paucity of genomic and endocrine knowledge of many crustacean model species; however this is rapidly changing with the advent of cheaper affordable genomic techniques and high throughput sequencing.

  16. Endemism in the Cladocera (Crustacea: Branchiopoda) of Southern Africa

    OpenAIRE

    2013-01-01

    We review the current state of knowledge and patterns of distribution in the endemic Cladocera (Crustacea: Branchiopoda) of Southern Africa and describe two species of the Western Cape, of which one is new to science. Frey (1993), Korovchinsky (2006) and Smirnov (2008) previously suggested that South Africa harbours few endemics in the Cladocera. In the current study, we show that so-called low endemism in this region is mainly attributed to our limited state of knowledge of the local clado...

  17. An annotated checklist of the Cladocera (Crustacea: Branchiopoda) of Colombia.

    Science.gov (United States)

    Kotov, Alexey A; Fuentes-Reinés, Juan M

    2015-11-20

    Based on the revision of available literature on the Colombian Cladocera (Crustacea: Branchiopoda), we present an annotated checklist, with taxonomical comments for all taxa recorded since the start of research on this group in the country in 1913. We have listed 101 valid taxa, of which most records belong to the Caribbean region of Colombia. The situation in Colombian Cladocera taxonomy is, at present, unfavorable for any realistic conclusions on biodiversity, ecology and biogeography.

  18. A simple control for sediment-toxicity exposures using the amphipod, Hyalella azteca.

    Science.gov (United States)

    Lasier, Peter J; Urich, Matthew L

    2014-09-01

    Sediment-toxicity exposures comparing survival and growth of the freshwater amphipod, Hyalella azteca, are often components of aquatic-habitat assessments. Standardized exposure methods have been established and require evaluations for quality assurance. Test acceptability using performance-based criteria can be determined from exposures to control sediments, which are collected from the environment or formulated from commercially available components. Amending sand with leached alfalfa solids provided a simple formulated sediment that elicited consistently acceptable survival and growth in 28-day exposures with and without a daily feeding regime. A procedure is described for preparing the sediment along with results from comparisons among sand, amended sand, and field-collected sediments that incorporated three feeding regimes.

  19. Synergistic effect of piperonyl butoxide on acute toxicity of pyrethrins to Hyalella azteca.

    Science.gov (United States)

    Giddings, Jeffrey; Gagne, James; Sharp, Janice

    2016-08-01

    A series of acute toxicity tests with the amphipod Hyalella azteca was performed to quantify the synergistic effect of piperonyl butoxide (PBO) on pyrethrin toxicity. Concentrations of PBO <4 µg/L caused no toxicity enhancement, whereas toxicity increased with PBO concentrations between 4 µg/L and 15 µg/L. Additive toxicity calculations showed that true synergism accounted for an increase in pyrethrin toxicity (decrease in median lethal concentration) of 1.4-fold to 1.6-fold and varied only slightly between 4 µg/L and 15 µg/L PBO, whereas direct toxicity of PBO accounted for an additional increase in mixture toxicity (up to 3.2-fold) that was proportional to PBO concentration. The results can be used to assess the risk of measured or predicted co-occurring concentrations of PBO and pyrethrins in surface waters. Environ Toxicol Chem 2016;35:2111-2116. © 2016 SETAC.

  20. Efficiency of experimental rice (Oryza sativa L.) fields in mitigating diazinon runoff toxicity to Hyalella azteca.

    Science.gov (United States)

    Moore, Matthew T; Lizotte, Richard E; Kröger, Robert

    2009-06-01

    This study assessed the viability of using planted, mature rice fields in mitigating diazinon (an organophosphate insecticide) runoff toxicity using aqueous 48 h Hyalella azteca whole effluent toxicity bioassays. Rice fields decreased diazinon concentrations 80.1%-99.9% compared with 10.8% in the unvegetated field control. H. azteca survival responses coincided with observed diazinon concentrations. Estimated LC50 effects dilutions (%) ranged from 1.15 to 1.47 for inflow samples and 1.66 (unvegetated), 6.44 (rice field A), and >100 (rice field B) outflow samples. Decreases in inflow versus outflow aqueous toxicity were 77.1%-100% in rice fields compared with 18.7% in the unvegetated field.

  1. Interactive effects of phosphorus and copper on Hyalella azteca via periphyton in aquatic ecosystems.

    Science.gov (United States)

    Li, Miling; Costello, David M; Burton, G Allen

    2012-09-01

    This research examined the interaction between dissolved copper and phosphorus, with respect to their effects on the freshwater amphipod Hyalella azteca feeding on periphyton. Field-collected periphyton communities were exposed to different nutrient and metal conditions in indoor recirculating streams. H. azteca were then exposed to water and periphyton from these streams. There was rapid Cu accumulation by periphyton but the total Cu concentration of periphyton was not directly related to dissolved P. In terms of H. azteca growth, an interactive effect was found between Cu and P as growth was reduced more than expected in the low Cu-high P treatment. Our data suggest that eutrophic conditions result in greater Cu toxicity to benthic macroinvertebrates at lower metal concentrations, likely due to higher assimilation efficiency of dietary Cu from periphyton incubated under eutrophic conditions. These results imply that non-additive interactions between multiple stressors may cause ecosystem effects as detected in standard laboratory bioassays conducted under controlled conditions.

  2. Diclofenac-enriched artificial sediment induces oxidative stress in Hyalella azteca.

    Science.gov (United States)

    Oviedo-Gómez, Dennis Gloria Carolina; Galar-Martínez, Marcela; García-Medina, Sandra; Razo-Estrada, Celene; Gómez-Oliván, Leobardo Manuel

    2010-01-01

    Diclofenac is a nonsteroidal anti-inflammatory drug widely used in Mexico where it is sold over the counter. It enters water bodies through municipal and industrial discharges, posing a risk to water systems and aquatic organisms. Diclofenac-enriched artificial sediment was used to evaluate the toxicity of this pharmaceutical on the sentinel species Hyalella azteca, using oxidative stress biomarkers in order to determine if the set of tests used in this study is a suitable early damage biomarker. The median lethal concentration (72-h LC(50)) was determined and oxidative stress was evaluated using lipid peroxidation, protein carbonyl content to evaluate oxidized protein content, and the activity of superoxide dismutase, catalase, and glutathione peroxidase. All biomarkers were significantly altered. Diclofenac induces oxidative stress in H. azteca and the set of tests used (lipid peroxidation, protein carbonyl content, antioxidant enzyme activities) constitutes an adequate early damage biomarker for evaluating the toxicity of this pharmaceutical group in aquatic species.

  3. Influence of bromide on the performance of the amphipod Hyalella azteca in reconstituted waters.

    Science.gov (United States)

    Ivey, Chris D; Ingersoll, Chris G

    2016-10-01

    Poor performance of the amphipod Hyalella azteca has been observed in exposures using reconstituted waters. Previous studies have reported success in H. azteca water-only exposures with the addition of relatively high concentrations of bromide. The present study evaluated the influence of lower environmentally representative concentrations of bromide on the response of H. azteca in 42-d water-only exposures. Improved performance of H. azteca was observed in reconstituted waters with >0.02 mg Br/L. Environ Toxicol Chem 2016;35:2425-2429. Published 2016 Wiley Periodicals Inc. on behalf of SETAC. This article is a US Government work and, as such, is in the public domain in the United States of America. Published 2016 Wiley Periodicals Inc. on behalf of SETAC. This article is a US Government work and, as such, is in the public domain in the United States of America.

  4. Effects of depleted uranium on the health and survival of Ceriodaphnia dubia and Hyalella azteca

    Science.gov (United States)

    Kuhne, W.W.; Caldwell, C.A.; Gould, W.R.; Fresquez, P.R.; Finger, S.

    2002-01-01

    Depleted uranium (DU) has been used as a substitute for the fissionable enriched uranium component of atomic weapons tested at Los Alamos National Laboratory (LANL) (Los Alamos, NM, USA) since the early 1950s, resulting in considerable concentrations of DU in the soils within the test sites. Although the movement of DU into major aquatic systems has been shown to be minimal, there are many small-order ephemeral streams and areas of standing water in canyons throughout LANL that may be affected by inputs of DU via runoff, erosion, and leaching. Ninety-six-hour acute and 7-d chronic toxicity assays were conducted to measure the toxicity of DU on survival and reproduction of Ceriodaphnia dubia. A 14-d water-only assay was conducted to measure survival and growth of Hyalella azteca. The estimated median lethal concentration (LC50) to produce 50% mortality of the test population for the 96-h Ceriodaphnia dubia assay was 10.50 mg/L. Reproductive effects occurred at a lowest-observable-effect concentration ???3.91 mg/L with a no-observable-effect concentration of 1.97 mg/L. The estimated 14-d LC50 for the Hyalella azteca assay was 1.52 mg/L No significant relationship was detected between growth and DU concentrations. Concentrations at which toxicity effects were observed in this study for both invertebrates exceeded concentrations of total uranium observed in runoff from LANL lands. Thus, it is likely that current runoff levels of uranium do not pose a threat to these types of aquatic invertebrates.

  5. Interlaboratory study of precision: Hyalella azteca and Chironomus tentans freshwater sediment toxicity assays

    Science.gov (United States)

    Burton, G.A.; Norberg-King, T. J.; Ingersoll, C.G.; Benoit, D.A.; Ankley, G.T.; Winger, P.V.; Kubitz, J.; Lazorchak, J.M.; Smith, M.E.; Greer, E.; Dwyer, F.J.; Call, D.J.; Day, K.E.; Kennedy, P.; Stinson, M.

    1996-01-01

    Standard 10-d whole-sediment toxicity test methods have recently been developed by the U.S. Environmental Protection Agency (EPA) for the amphipod Hyalella azteca and the midge Chironomus tentans. An interlaboratory evaluation of method precision was performed using a group of seven to 10 laboratories, representing government, academia, and environmental consulting firms. The test methods followed the EPA protocols for 4-d water-only reference toxicant (KCl) testing (static exposure) and for 10-d whole-sediment testing. Test sediments included control sediment, two copper-containing sediments, and a sediment contaminated primarily with polycyclic aromatic hydrocarbons. Reference toxicant tests resulted in H. azteca and C. tentans median lethal concentration (LC50) values with coefficents of variation (CVs) of 15.8 and 19.6%, respectively. Whole sediments which were moderately contaminated provided the best estimates of precision using CVs. Hyalella azteca and C. tentans tests in moderately contaminated sediments exhibited LC50 CVs of 38.9 and 13.5%, respectively. The CV for C. tentans growth was 31.9%. Only 3% (1 of 28) of samples exceeded acceptable interlaboratory precision limits for the H. azteca survival tests. No samples exceeded the intralaboratory precision limit for H. azteca or C. tentans survival tests. However, intralaboratory variability limits for C. tentans growth were exceeded by 80 and 100% of the laboratories for a moderately toxic and control sample, respectively. Interlaboratory variability limits for C. tentans survival were not exceeded by any laboratory. The results showed these test methods to have relatively low variance and acceptable levels of precision in interlaboratory comparisons.

  6. Effects of an atrazine, metolachlor and fipronil mixture on Hyalella azteca (Saussure) in a modified backwater wetland.

    Science.gov (United States)

    Lizotte, Richard E; Knight, Scott S; Shields, F Douglas; Bryant, Charles T

    2009-12-01

    We examined the toxicity mitigation efficiency of a hydrologically modified backwater wetland amended with a pesticide mixture of atrazine, metolachlor, and fipronil, using 96 h survival bioassays with Hyalella azteca. Significant H. azteca 96 h mortality occurred within the first 2 h of amendment at the upstream amendment site but not at any time at the downstream site. H. azteca survival varied spatially and temporally in conjunction with measured pesticide mixture concentrations. Hyalella azteca 96 h survival pesticide mixture effects concentrations ranges were 10.214–11.997, 5.822–6.658, 0.650–0.817, and 0.030–0.048 μg L−1 for atrazine, metolachlor, fipronil, and fipronil-sulfone, respectively.

  7. NMR-based metabolomics for the environmental assessment of Kaohsiung Harbor sediments exemplified by a marine amphipod (Hyalella azteca).

    Science.gov (United States)

    Chiu, K H; Dong, C D; Chen, C F; Tsai, M L; Ju, Y R; Chen, T M; Chen, C W

    2017-03-03

    Inflow of wastewater from upstream causes a large flux of pollutants to enter Kaohsiung Harbor in Taiwan daily. To reveal the ecological risk posed by Kaohsiung Harbor sediments, an ecological metabolomic approach was employed to investigate environmental factors pertinent to the physiological regulation of the marine amphipod Hyalella azteca. The amphipods were exposed to sediments collected from different stream inlets of the Love River (LR), Canon River (CR), Jen-Gen River (JR), and Salt River (SR). Harbor entrance 1 (E1) was selected as a reference site. After 10-day exposure, metabolomic analysis of the Hyalella azteca revealed differences between two groups: {E1, LR, CR} and {JR, SR}. The metabolic pathways identified in the two groups of amphipods were significantly different. The results demonstrated that NMR-based metabolomics can be effectively used to characterize metabolic response related to sediment from polluted areas.

  8. 40 CFR 180.1071 - Peanuts, Tree Nuts, Milk, Soybeans, Eggs, Fish, Crustacea, and Wheat; exemption from the...

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 23 2010-07-01 2010-07-01 false Peanuts, Tree Nuts, Milk, Soybeans... Peanuts, Tree Nuts, Milk, Soybeans, Eggs, Fish, Crustacea, and Wheat; exemption from the requirement of a..., tree nuts, milk, soybeans, eggs (including putrescent eggs), fish, crustacea, and wheat are exempted...

  9. Relative contribution of food and water to 27 metals and metalloids accumulated by caged Hyalella azteca in two rivers affected by metal mining

    Energy Technology Data Exchange (ETDEWEB)

    Borgmann, U. [Water Science and Technology Directorate, Environment Canada, 867 Lakeshore Road, Burlington, ON, L7R 4A6 (Canada)]. E-mail: uwe.borgmann@ec.gc.ca; Couillard, Y. [Existing Substances Division, Environment Canada, 351 Saint-Joseph Boulevard, Gatineau, QC, K1A 0H3 (Canada); Grapentine, L.C. [Water Science and Technology Directorate, Environment Canada, 867 Lakeshore Road, Burlington, ON, L7R 4A6 (Canada)

    2007-02-15

    Hyalella were caged at three sites in each of the two rivers for 17 days. Food added to the cages consisted of plant and detrital material collected from the same, or other, sites. Concentrations of some metals in Hyalella (e.g., Cd and Cu), but not others (e.g., Se), appeared to reach steady-state within 5 days in one of the rivers. Metal accumulation was minimal by day 5 in the other river, possibly due to the very low temperatures in this river for the first part of the exposure period. Both analysis of variance and analysis of covariance, using site as a categorical variable and metal in food as either a categorical or continuous variable, indicated that Cd, Cu and Se were the only metals for which concentration in food had a significant effect on concentration in Hyalella. Nevertheless, water was still a major source for these metals as well. Other metals which varied by over fivefold in food but for which concentration in food had no effect on concentration in Hyalella included Ag, As, Bi, Sb, U and Zn. Concentrations of the remaining metals varied less than fourfold in food, making it difficult to determine if these were accumulated from food. - Cadmium, copper and selenium were the only metals in food that correlated with increased body concentrations of metals in Hyalella, but even these metals were accumulated largely from water.

  10. Water-sediment interactions for Hyalella azteca exposed to uranium-spiked sediment

    Energy Technology Data Exchange (ETDEWEB)

    Alves, L.C. [Department of Biology, University of Waterloo, Waterloo, ON N2L 3G1 (Canada); Aquatic Ecosystems Protection Research Division, Environment Canada, P.O. Box 5050, Burlington, ON L7R 4A6 (Canada)], E-mail: Lara.Alves@ec.gc.ca; Borgmann, U. [Aquatic Ecosystems Protection Research Division, Environment Canada, P.O. Box 5050, Burlington, ON L7R 4A6 (Canada); Dixon, D.G. [Department of Biology, University of Waterloo, Waterloo, ON N2L 3G1 (Canada)

    2008-05-01

    Data on the toxicity of uranium in sediments to Hyalella azteca and the effect of overlying water chemistry are limited. This study exposed H. azteca to sediments spiked with U (0-10,000 {mu}g U/g dry weight) and five different overlying waters, which varied independently in hardness and alkalinity. Water pH had a major effect on U bioavailability and uptake by H. azteca. Uranium toxicity was higher when overlying water pH was low, while desorption of U into the overlying water increased with increasing pH. There appears to be little effect of Ca on U uptake, other than its influence on U speciation. Experiments with caged animals indicate that U accumulation and toxicity occur mainly through the dissolved phase rather than the solid phase. Uranium bioaccumulation is a more reliable indicator of U toxicity than U concentration in water or sediment. Uranium bioaccumulation in the H. azteca and U adsorption to sediment can be satisfactorily explained using saturation models.

  11. Testing Local Adaptation in Five Populations of Hyalella azteca in Northern Alberta's Oil Sands Region.

    Science.gov (United States)

    Beery, Steven R; Gauthier, Patrick T; Pyle, Gregory G

    2017-02-01

    Canada's oil sands hold the third largest petroleum reserves worldwide and have experienced rapid economic growth. The oil sands region provides an ideal location for studying local adaptations through reciprocal transplant (RT) because populations within the region have been historically exposed to naturally occurring bitumen. Our objectives were to (1) determine if Hyalella azteca from habitats within the oil sands region exhibited increased tolerance to constituents associated with industrial bitumen extraction compared with H. azteca from habitats outside the region; and (2) determine if any observed tolerance was attributable to local adaptation. Five populations of H. azteca were reciprocally transplanted from reclaimed and reference wetlands: four from local wetlands plus one naïve laboratory population. Survival, toxicity, and behaviour were measured before and after the RT period. Survival varied by population and site. These results show that the differences in responses among populations are likely not attributable to local adaptation and that laboratory populations of H. azteca provide ecologically relevant results when tested in the field.

  12. Responses of phytoplankton and Hyalella azteca to agrichemical mixtures in a constructed wetland mesocosm.

    Science.gov (United States)

    Lizotte, Richard E; Testa, Sam; Locke, Martin A; Steinriede, R Wade

    2013-10-01

    We assessed the capability of a constructed wetland to mitigate toxicity of a variety of possible mixtures, such as nutrients only (NO) (nitrogen [N], phosphorus [P]), pesticides only (PO) (atrazine, S-metolachlor, permethrin), and nutrients + pesticides on phytoplankton chlorophyll-a, on 48-h aqueous Hyalella azteca survival and 10-day sediment H. azteca survival and growth. Water and sediment were collected at 10-, 20-, and 40-m distances from inflow and analyzed for nutrients, pesticides, chlorophyll-a, and H. azteca laboratory bioassays. Phytoplankton chlorophyll-a increased 4- to 10 -fold at 7 days after NO treatment. However, responses of chlorophyll-a to PO and nutrients + pesticides were more complex with associated decreases at only 20 m for pesticides only and 10 and 40 m for nutrients + pesticides treatments. H. azteca aqueous survival decreased within the first 48 h of dosing at 10- and 20-m distances during PO and nutrients + pesticides treatments in association with permethrin concentrations. H. azteca sediment survival was unaffected, whereas 10-day growth decreased within 1 day of dosing at all sites during nutrients + pesticides treatment. Constructed wetlands were shown to be an effective agricultural best-management tool for trapping pollutants and mitigating ecological impacts of run-off in agricultural watersheds.

  13. Effect of test duration and feeding on relative sensitivity of genetically distinct clades of Hyalella azteca.

    Science.gov (United States)

    Soucek, David J; Dickinson, Amy; Major, Kaley M; McEwen, Abigail R

    2013-11-01

    The amphipod Hyalella azteca is widely used in ecotoxicology laboratories for the assessment of chemical risks to aquatic environments, and it is a cryptic species complex with a number of genetically distinct strains found in wild populations. While it would be valuable to note differences in contaminant sensitivity among different strains collected from various field sites, those findings would be influenced by acclimation of the populations to local conditions. In addition, potential differences in metabolism or lipid storage among different strains may confound assessment of sensitivity in unfed acute toxicity tests. In the present study, our aim was to assess whether there are genetic differences in contaminant sensitivity among three cryptic provisional species of H. azteca. Therefore, we used organisms cultured under the same conditions, assessed their ability to survive for extended periods without food, and conducted fed and unfed acute toxicity tests with two anions (nitrate and chloride) whose toxicities are not expected to be altered by the addition of food. We found that the three genetically distinct clades of H. azteca had substantially different responses to starvation, and the presence/absence of food during acute toxicity tests had a strong role in determining the relative sensitivity of the three clades. In fed tests, where starvation was no longer a potential stressor, significant differences in sensitivity were still observed among the three clades. In light of these differences in sensitivity, we suggest that ecotoxicology laboratories consider using a provisional species in toxicity tests that is a regionally appropriate surrogate.

  14. Role of vegetation in a constructed wetland on nutrient-pesticide mixture toxicity to Hyalella azteca.

    Science.gov (United States)

    Lizotte, Richard E; Moore, Matthew T; Locke, Martin A; Kröger, Robert

    2011-02-01

    The toxicity of a nutrient-pesticide mixture in nonvegetated and vegetated sections of a constructed wetland (882 m² each) was assessed using Hyalella azteca 48-h aqueous whole-effluent toxicity bioassays. Both sections were amended with a mixture of sodium nitrate, triple superphosphate, diazinon, and permethrin simulating storm-event agricultural runoff. Aqueous samples were collected at inflow, middle, and outflow points within each section 5 h, 24 h, 72 h, 7 days, 14 days, and 21 days postamendment. Nutrients and pesticides were detected throughout both wetland sections with concentrations longitudinally decreasing more in vegetated than nonvegetated section within 24 h. Survival effluent dilution point estimates-NOECs, LOECs, and LC₅₀s-indicated greatest differences in toxicity between nonvegetated and vegetated sections at 5 h. Associations of nutrient and pesticide concentrations with NOECs indicated that earlier toxicity (5-72 h) was from permethrin and diazinon, whereas later toxicity (7-21 days) was primarily from diazinon. Nutrient-pesticide mixture concentration-response assessment using toxic unit models indicated that H. azteca toxicity was due primarily to the pesticides diazinon and permethrin. Results show that the effects of vegetation versus no vegetation on nutrient-pesticide mixture toxicity are not evident after 5 h and a 21-day retention time is necessary to improve H. azteca survival to ≥90% in constructed wetlands of this size.

  15. Effect of gut clearance on metal body concentrations in Hyalella azteca

    Energy Technology Data Exchange (ETDEWEB)

    Neumann, P.T.M.; Borgmann, U.; Norwood, W. [Environment Canada, Burlington, Ontario (Canada)

    1999-05-01

    Gut content can contribute significantly to the metal body burdens in sediment-exposed Hyalella azteca even if it has no direct effect on toxicity. To determine the duration and the effect of gut clearance on total body concentrations, the authors exposed H. azteca for 1 week to a spiked sediment (lead, cadmium, zinc, and copper); a second set of amphipods was kept in cages above the sediment. Following transfer into clean water (25 C) for 96 h, lead and zinc concentrations showed a biphasic decline, with a stronger decrease in the first 4 to 6 h, when gut clearance contributes significantly to metal loss. After 6 h, metal loss was apparently due to excretion from the body. Without gut clearance, the body concentrations of lead and zinc in sediment-exposed amphipods were overestimated by 438 and 44%, respectively. Gut clearance did not have a visible effect on cadmium and copper body burdens because the body and sediment concentrations were similar. After a depuration time of 6 h, direct excretion from the body resulted in a drop of less than 10% in the total body burdens of lead, cadmium, zinc, and copper compared to the gut-corrected time-zero body burdens. After 24 h, this loss increased up to 27%. Feeding during the depuration period did not have a significant influence on gut clearance. A model that allows estimation of the influence of gut content on the total body concentration of undepurated invertebrates from the bioconcentration factor is evaluated.

  16. Bioavailability-based toxicity endpoints of bifenthrin for Hyalella azteca and Chironomus dilutus.

    Science.gov (United States)

    Harwood, Amanda D; Landrum, Peter F; Lydy, Michael J

    2013-01-01

    Recent studies have determined that techniques, such as solid phase microextraction (SPME) fibers and Tenax beads, can predict bioaccumulation and potentially could predict toxicity for several compounds and species. Toxicity of bifenthrin was determined using two standard sediment toxicity tests with the benthic species Hyalella azteca and Chironomus dilutus in three reference sediments with different characteristics. The objectives of the current study were to establish bioavailability-based median lethal concentrations (LC50) and median effect concentrations (EC50) of the pyrethroid insecticide bifenthrin, compare their ability to assess toxicity to the use of whole sediment concentrations, as well as to make comparisons of the concentrations derived using each method in order to make assessments of accuracy and extrapolation potential. Four metrics were compared including SPME fiber concentration, pore water concentration derived using SPMEs, 6 h Tenax extractable concentration, and 24 h Tenax extractable concentration. The variation among the LC50s and EC50s in each sediment derived using bioavailability-based methods was comparable to variation among organic carbon normalized sediment concentrations, but improved over whole sediment concentrations. There was a significant linear relationship between SPME or Tenax and organic carbon normalized sediment concentrations. Additionally, there was a significant relationship between the SPME and Tenax concentrations across sediments. The significant linear relationship between SPME and Tenax concentrations further demonstrates that these bioavailability-based endpoints are interrelated. This study derived bioavailability-based benchmarks that may prove to be more accurate than sediment-based ones in predicting toxicity across sediment types.

  17. Genotype and toxicity relationships among Hyalella azteca: II. Acute exposure to fluoranthene-contaminated sediment

    Energy Technology Data Exchange (ETDEWEB)

    Duan, Y.; Guttman, S.I.; Oris, J.T.; Huang, X.; Burton, G.A.

    2000-05-01

    This study examined the genotypic responses of Hyalella azteca to the toxicity of sediment contaminated by the polycyclic aromatic hydrocarbon (PAH) fluoranthene. The authors monitored the time to death for 696 H. azteca exposed to ultraviolet light and sediment spiked with fluoranthene. The survival distribution functions within the genotypes at each of these variable allozyme loci (acid phosphatase [ACP*], glucose-6-phosphate isomerase [GPI*], and phosphoglucomutase [PGM*]) were compared using a long-rank test. Results showed significant differences among SDFs at all three loci. No association of heterozygosity with time to death was observed. The homozygote ACP*-CC was associated with decreased survivorship compared with ACP*-AA, ACP*-BB, and ACP*-AB. However, GPI*-AA was associated with increased survivorship compared with GPI*-BB, GPI*-CC, and GPI*-BC. Significant differences in resistance also were observed for PGM*-BB versus either PGM*-AC or PGM*-BC. These results indicate that differential resistance to PAH phototoxicity was genetically related, producing significant alteration in the frequencies of several genotypes in the population.

  18. Time-dependent lethal body residues for the toxicity of pentachlorobenzene to Hyalella azteca

    Science.gov (United States)

    Landrum, Peter F.; Steevens, Jeffery A.; Gossiaux, Duane C.; McElroy, Michael; Robinson, Sander; Begnoche, Linda; Chernyak, Sergei; Hickey, James

    2004-01-01

    The study examined the temporal response of Hyalella azteca to pentachlorobenzene (PCBZ) in water-only exposures. Toxicity was evaluated by calculating the body residue of PCBZ associated with survival. The concentration of PCBZ in the tissues of H. azteca associated with 50% mortality decreased from 3 to 0.5 μmol/g over the temporal range of 1 to 28 d, respectively. No significant difference was observed in the body residue calculated for 50% mortality when the value was determined using live or dead organisms. Metabolism of PCBZ was not responsible for the temporal response because no detectable PCBZ biotransformation occurred over an exposure period of 10 d. A damage assessment model was used to evaluate the impact and repair of damage by PCBZ on H. azteca. The toxicokinetics were determined so that the temporal toxicity data could be fit to a damage assessment model. The half-life calculated for the elimination of PCBZ averaged approximately 49 h, while the value determined for the half-life of damage repair from the damage assessment model was 33 h.

  19. Water-sediment interactions for Hyalella azteca exposed to uranium-spiked sediment.

    Science.gov (United States)

    Alves, L C; Borgmann, U; Dixon, D G

    2008-05-01

    Data on the toxicity of uranium in sediments to Hyalella azteca and the effect of overlying water chemistry are limited. This study exposed H. azteca to sediments spiked with U (0-10,000 microg U/g dry weight) and five different overlying waters, which varied independently in hardness and alkalinity. Water pH had a major effect on U bioavailability and uptake by H. azteca. Uranium toxicity was higher when overlying water pH was low, while desorption of U into the overlying water increased with increasing pH. There appears to be little effect of Ca on U uptake, other than its influence on U speciation. Experiments with caged animals indicate that U accumulation and toxicity occur mainly through the dissolved phase rather than the solid phase. Uranium bioaccumulation is a more reliable indicator of U toxicity than U concentration in water or sediment. Uranium bioaccumulation in the H. azteca and U adsorption to sediment can be satisfactorily explained using saturation models.

  20. The amphipod Hyalella azteca as a biomonitor in field deployment studies for metal mining.

    Science.gov (United States)

    Couillard, Y; Grapentine, L C; Borgmann, U; Doyle, P; Masson, S

    2008-12-01

    Specimens of the amphipod Hyalella azteca were deployed, in June-July 2003, along metal contamination gradients in two rivers affected by metal mining in the Abitibi-James Bay region, northwestern Québec. The amphipods were placed along with natural food items in small, acrylic cages and left in six riverine sites for 17 days. Twelve metals (As, Cu, La, Mn, Ni, Sb, Se, Tl, U, V, Zn, and CrO4(2-) modelled by WHAM VI) in transplanted H. azteca varied along metal contamination gradients in a consistent manner, i.e., as a function of metal exposure. Bioaccumulation of As, Cr, La, Ni, Sb, Se, Tl, U and V, as defined by a field BCF, was significantly correlated with their chronic toxicity potential towards the amphipod. We conclude that H. azteca may be a useful field biomonitor for metal mining. In addition, our results suggest that such biomonitoring programs should include less studied elements such as Se in mining effluents.

  1. Testing sediment biological effects with the freshwater amphipod Hyalella azteca: the gap between laboratory and nature.

    Science.gov (United States)

    Wang, Feiyue; Goulet, Richard R; Chapman, Peter M

    2004-12-01

    The freshwater amphipod, Hyalella azteca, is widely used in laboratory sediment toxicity and bioaccumulation tests. However, its responses in the laboratory are probably very different from those in the field. A review of the literature indicates that in its natural habitat this species complex is primarily epibenthic, derives little nutrition from the sediments, and responds primarily to contaminants in the overlying water column (including water and food), not sediment or porewater. In laboratory sediment toxicity tests H. azteca is deprived of natural food sources such as algal communities on or above the sediments, and is subjected to constant light without any cover except that afforded by burial into the sediments. Under these constraining laboratory conditions, H. azteca has been reported to respond to sediment or porewater contamination. In nature, contamination of overlying water from sediment is less likely than in the laboratory because of the large, generally non-static sink of natural surface water. H. azteca does not appear to be the most appropriate test species for direct assessments of the bioavailability and toxicity of sediment contaminants, though it is probably appropriate for testing the toxicity of surface waters. Toxic and non-toxic responses will be highly conservative, though the latter are probably the most persuasive given the exposure constraints. Thus H. azteca is probably a suitable surrogate species for determining sediments that are likely not toxic to field populations; however, it is not suitable for determining sediments that are likely toxic to field populations.

  2. Toxicity of four sulfonamide antibiotics to the freshwater amphipod Hyalella azteca.

    Science.gov (United States)

    Bartlett, Adrienne J; Balakrishnan, V K; Toito, J; Brown, L R

    2013-04-01

    Sulfonamides are a widely used class of antibiotics; however, there are few toxicological data available with which to conduct environmental risk assessments for these compounds. Therefore, the toxicity of four sulfonamides (sulfaguanidine, sulfathiazole, sulfamerazine, and sulfasalazine) to Hyalella azteca was assessed in chronic (four-week), water-only exposures. Survival was evaluated weekly, and growth was measured at the end of the test. Four-week lethal concentrations associated with 50% mortality (LC50s) for sulfaguanidine, sulfathiazole, and sulfamerazine were 0.90, 1.6, and 3.9 µM, respectively. Sulfaguanidine caused effects on survival more quickly and at lower concentrations than sulfathiazole or sulfamerazine. These differences were more pronounced at week 1 than week 4, when sulfaguanidine LC50s were 8 to 20 times lower and 2 to 4 times lower, respectively. Growth was affected by sulfathiazole but was a less sensitive end point than survival, with an effective concentration associated with 50% reduction in growth (EC50) of 13 µM, whereas sulfaguanidine and sulfamerazine caused negligible effects on growth. Sulfasalazine had no effect on survival or growth at any concentration tested, up to 13 µM. The effects observed in the present study occurred at concentrations exceeding those typically found in environmental waters. However, given that LC50s decreased with exposure duration (except for sulfasalazine), the present study demonstrates the importance of conducting longer-term tests to adequately assess the environmental toxicity of sulfonamides.

  3. Effects of copper in flooded Florida agricultural soils on Hyalella azteca.

    Science.gov (United States)

    Hoang, Tham C; Schuler, Lance J; Rand, Gary M

    2009-04-01

    This study examined the uptake and effects of copper (Cu) from flooded agricultural soils to epibenthic amphipods (Hyalella azteca) using 10-day sediment toxicity tests. Soils were collected from 10 citrus agricultural sites in South Florida. One sediment toxicity test was conducted with one flooding of the 10 soils, and based on the results of this test a second sediment toxicity test was conducted with 4 of the soils, after four 14-day flooding and four 14-day drying intervals over 4 months. Sediment toxicity tests were conducted under flow-through conditions using U.S. EPA methodology. Effects on survival, dry weight, and whole-body Cu concentrations of H. azteca were determined. Cu concentrations in overlying water and sediment of both sediment toxicity tests exceeded regulatory criteria for aquatic organisms. Although survival of H. azteca was not consistently affected from the first to the second sediment toxicity tests, dry weight was consistently reduced and related to Cu concentrations in soil, overlying water, and pore water. Furthermore, whole-body tissue Cu concentrations were significantly higher in H. azteca in all 10 soil-water treatments in the first sediment toxicity test and in all 4 soil-water treatments in the second sediment toxicity test compared to controls. Whole-body tissue concentrations and effects on dry weight were related to Cu exposures in soil, overlying water, and pore water. In these managed soil-water systems, small fish consuming H. azteca with high concentrations of Cu may be at risk.

  4. Agricultural pesticides in Mississippi Delta oxbow lake sediments during autumn and their effects on Hyalella azteca.

    Science.gov (United States)

    Lizotte, Richard E; Knight, Scott S; Bryant, Charles T; Smith, Sammie

    2009-10-01

    Agricultural pesticide contamination of sediments from five Mississippi Delta oxbow lakes and their effects and bioavailablity to Hyalella azteca were assessed during a low-application season-autumn. Three reference oxbow lakes were located in the White River National Wildlife Refuge (WRNWR), Arkansas and two impaired lakes, according to the US Environmental Agency Sect. 303 (d) Clean Water Act, were located in Mississippi. Surface sediment (top 5 cm) was collected at three sites within each lake and analyzed for 17 current and historic-use pesticides and metabolites. Chronic 28-day H. azteca sediment bioassays and pesticide body residue analyses were completed to determine the degree of biological responses and bioavailability. The greatest number of detectable pesticides in WRNWR and 303 (d) sediment samples was 9 and 12, respectively, with historic-use pesticide metabolite, p,p'-DDE [1,1-dichloro-2,2-bis(p-chlorophenyl)ethylene] ubiquitous. No significant (p > 0.05) differences in animal survival were observed among sites. Animal growth was significantly (p azteca with current-use pesticides detected at three sites; historic-use pesticides and metabolites detected at 11 sites. Animal body residues of a historic-use pesticide (dieldrin) and metabolite (p,p'-DDE) were associated with observed growth responses. Results show limited current-use pesticide contamination of sediments and H. azteca body tissues during autumn and that historic-use pesticides and metabolites are the primary contributors to observed biological responses.

  5. Lac Dufault sediment core trace metal distribution, bioavailability and toxicity to Hyalella azteca

    Energy Technology Data Exchange (ETDEWEB)

    Nowierski, Monica [Department of Biology, University of Waterloo, 200 University Avenue West, Waterloo, Ontario N2L 3G1 (Canada); Dixon, D. George [Department of Biology, University of Waterloo, 200 University Avenue West, Waterloo, Ontario N2L 3G1 (Canada); Borgmann, Uwe [National Water Research Institute, Canada Centre for Inland Waters, 867 Lakeshore Road, PO Box 5050, Burlington, Ontario L7R 4A6 (Canada)]. E-mail: uwe.borgmann@ec.gc.ca

    2006-02-15

    To determine changes in metal distribution, bioavailability and toxicity with sediment depth, two 20-cm-long replicate cores were collected from a lake historically subjected to the influence of metal mining and smelting activity. The vertical distribution of Pb, Cd and Cu in sediment was similar for all three metals, with the surface layers showing enrichment and the deeper (pre-industrial) layers showing lower concentrations. Toxicity of each sediment core section was determined in laboratory tests with the freshwater amphipod Hyalella azteca. Bioavailable metal in each sediment slice was estimated from metal concentrations in overlying water in these toxicity tests and, for Cd, also from metal bioaccumulation. The profile for Cd in tissue was comparable to Cd in sediment and overlying water, but relative Cd bioavailability from sediment increased with sediment depth. Survival increased with increasing sediment depth, suggesting that surface sediments were probably less or non-toxic before industrialization. - Toxicity and bioaccumulation tests with sediment cores provide more information on biological effects of metals than surface sediment tests.

  6. Acute and chronic toxicity of lead in water and diet to the amphipod Hyalella azteca

    Science.gov (United States)

    Besser, J.M.; Brumbaugh, W.G.; Brunson, E.L.; Ingersoll, C.G.

    2005-01-01

    We evaluated the influence of waterborne and dietary lead (Pb) exposure on the acute and chronic toxicity of Pb to the amphipod Hyalella azteca. Test solutions were generated by a modified diluter with an extended (24-h) equilibration period. Acute (96-h) toxicity of Pb varied with water hardness in the range of 71 to 275 mg/L as CaCO3, despite similar dissolved Pb concentrations. Acute toxicity was greatest in soft test water, with less than 50% survival at the lowest dissolved Pb concentration (151 ??g/L). Survival also was significantly reduced in medium-hardness water but not in hard test water. In chronic (42-d) studies, amphipods were exposed to waterborne Pb and fed either a control diet or a diet equilibrated with waterborne Pb levels. For animals fed the control diet, the median lethal concentration (LC50) for Pb was 24 ??g/L (as dissolved Pb), and significant reductions in survival occurred at 16 ??g/L. Exposure to Pb-treated diets significantly increased toxicity across a wide range of dissolved Pb concentrations, with a LC50 of 16 ??g/L and significant reductions in growth and reproduction at 3.5 ??g/L. Significant effects on growth and reproduction occurred at dissolved Pb concentrations close to the current U.S. chronic water-quality criterion. Our results suggest that both aqueous- and dietary-exposure pathways contribute significantly to chronic Pb exposure and toxic effects in aquatic biota. ?? 2005 SETAC.

  7. Modeling chronic dietary cadmium bioaccumulation and toxicity from periphyton to Hyalella azteca.

    Science.gov (United States)

    Golding, Lisa A; Borgmann, Uwe; Dixon, D George

    2011-07-01

    A chronic (28-d) Cd saturation bioaccumulation model was developed to quantify the Cd contribution from a natural periphyton diet to Cd in the freshwater amphipod Hyalella azteca. Bioaccumulation was then linked to chronic toxic effects. Juvenile H. azteca were exposed to treatments of Cd in water (3.13-100 nmol/L nominal) and food (389-26,300 nmol/g ash-free dry mass). Cadmium bioaccumulation, survival, and growth were recorded. Dietary Cd was estimated to contribute 21 to 31, 59 to 94, and 40 to 55% to bioaccumulated Cd in H. azteca exposed to treatments of Cd primarily in water, food, and food + water, respectively. Survival as a function of Cd lethal body concentration (679 nmol/g; 95% confidence limits, 617-747) was the most robust endpoint. Body concentration integrated all exposure routes. Based on the lethal body concentration, dietary Cd was predicted to contribute markedly (26-90%) to Cd in H. azteca. Cadmium concentration and food nutritional quality (biomass, chlorophyll a, total lipid, fatty acids, total protein) had no effect on H. azteca nutritional quality (total lipid, fatty acids, total protein) but did influence H. azteca dry weight. This research highlighted the importance of including a dietary component when modeling chronic effects of Cd and when refining endpoints for use in ecological risk assessment and water quality guidelines.

  8. Decamethylcyclopentasiloxane (D5) spiked sediment: bioaccumulation and toxicity to the benthic invertebrate Hyalella azteca.

    Science.gov (United States)

    Norwood, W P; Alaee, M; Sverko, E; Wang, D; Brown, M; Galicia, M

    2013-10-01

    Chronic toxicity and bioaccumulation of decamethylcyclopentasiloxane (D5) to Hyalella azteca was examined in a series of spiked sediment exposures. Juvenile H. azteca were exposed for 28d (chronic) to a concentration series of D5 in two natural sediments of differing organic carbon content (O.C.) and particle size composition. The chronic, LC50s were 191 and 857μgD5g(-1) dry weight for Lakes Erie (0.5% O.C.) and Restoule (11% O.C.) respectively. Inhibition of growth only occurred with the L. Restoule spiked sediment with a resultant EC25 of 821μgg(-1)dw. Lethality was a more sensitive endpoint than growth inhibition. Biota sediment accumulation factors (BSAFs, 28d) were <1 indicating that D5 did not bioconcentrate based on lipid normalized tissue concentrations and organic carbon normalized sediment concentrations. Organic carbon (OC) in the sediment appeared to be protective, however normalization to OC did not normalize the toxicity. Normalization of D5 concentrations in the sediments to sand content did normalize the toxicity and LC50 values of 3180 and 3570μg D5g(-1) sand dw were determined to be statistically the same.

  9. Uptake and speciation of vanadium in the benthic invertebrate Hyalella azteca.

    Science.gov (United States)

    Jensen-Fontaine, Madeleine; Norwood, Warren P; Brown, Mitra; Dixon, D George; Le, X Chris

    2014-01-01

    Vanadium has the potential to leach into the environment from petroleum coke, an oil sands byproduct. To determine uptake of vanadium species in the biota, we exposed the benthic invertebrate Hyalella azteca with increasing concentrations of two different vanadium species, V(IV) and V(V), for seven days. The concentrations of vanadium in the H. azteca tissue increased with the concentration of vanadium in the exposure water. Speciation analysis revealed that V(IV) in the exposure water was oxidized to V(V) between renewal periods, and therefore the animals were mostly exposed to V(V). Speciation analysis of the H. azteca tissue showed the presence of V(V), V(IV), and an unidentified vanadium species. These results indicate the uptake and metabolism of vanadium by H. azteca. Because H. azteca are widely distributed in freshwater systems and are an important food supply for many fish, determining the uptake and metabolism of vanadium allows for a better understanding of the potential environmental effects on invertebrates.

  10. Influence of container adsorption upon observed pyrethroid toxicity to Ceriodaphnia dubia and Hyalella azteca

    Science.gov (United States)

    Wheelock, Craig E.; Miller, Jeff L.; Miller, Mike J.; Phillips, Bryn M.; Gee, Shirley J.; Tjeerdema, Ronald S.; Hammock, Bruce D.

    2006-01-01

    Pyrethroid insecticides are known for their potential toxicity to aquatic invertebrates and many fish species. A significant problem in the study of pyrethroid toxicity is their extreme hydrophobicity. They can adsorb to test container surfaces and many studies, therefore, report pyrethroid levels as nominal water concentrations. In this study, pyrethroid adsorption to sampling and test containers was measured and several container treatments were examined for their ability to decrease pyrethroid adsorption. None of the chemical treatments were successful at preventing pyrethroid loss from aqueous samples, but vortexing of containers served to resuspend pyrethroids. The effects of the observed adsorption on Ceriodaphnia dubia and Hyalella azteca permethrin toxicity were examined. Species-specific results showed a time-dependent decrease in toxicity following pyrethroid adsorption to test containers for C. dubia, but not for H. azteca. These results demonstrate that pyrethroid adsorption to containers can significantly affect the observed outcome in toxicity-testing and serves as a caution for researchers and testing laboratories. PMID:15951033

  11. Influence of chloride on the chronic toxicity of sodium nitrate to Ceriodaphnia dubia and Hyalella azteca.

    Science.gov (United States)

    Soucek, David J; Dickinson, Amy

    2016-09-01

    While it has been well established that increasing chloride concentration in water reduces the toxicity of nitrite to freshwater species, little work has been done to investigate the effect of chloride on nitrate toxicity. We conducted acute and chronic nitrate (as sodium nitrate) toxicity tests with the cladoceran Ceriodaphnia dubia and the amphipod Hyalella azteca (chronic tests only) over a range of chloride concentrations spanning natural chloride levels found in surface waters representative of watersheds of the Great Lakes Region. Chronic nitrate toxicity test results with both crustaceans were variable, with H. azteca appearing to be one of the more sensitive invertebrate species tested and C. dubia being less sensitive. While the variability in results for H. azteca were to an extent related to chloride concentration in test water that was distinctly not the case for C. dubia. We concluded that the chloride dependent toxicity of nitrate is not universal among freshwater crustaceans. An additional sodium chloride chronic toxicity test with the US Lab strain of H. azteca in the present study suggested that when present as predominantly sodium chloride and with relatively low concentrations of other ions, there is a narrow range of chloride concentrations over which this strain is most fit, and within which toxicity test data are reliable.

  12. Response spectrum of pentachlorobenzene and fluoranthene for Chironomus tentans and Hyalella azteca.

    Science.gov (United States)

    Schuler, Lance J; Landrum, Peter F; Lydy, Michael J

    2007-06-01

    The whole-body residues of pentachlorobenzene (PCBz) and fluoranthene (FLU) in Hyalella azteca and Chironomus tentans were determined for a variety of chronic sublethal effects. The endpoints evaluated for H. azteca included 28-d growth and survival and 42-d growth, survival, and reproduction. Adverse effects to C. tentans also were determined at multiple endpoints including 10-d growth, cumulative pupation and emergence, and reproduction. The lowest-observed-effect residue (LOER) based on whole-body residues associated with growth was consistent between compounds and species tested with concentrations ranging from 0.17 to 0.33 micromol/g. For H. azteca, the most sensitive endpoints were growth at 0.23 micromol/g and reproduction at 0.11 micromol/g for PCBz and FLU, respectively. For C. tentans, the most sensitive endpoints were emergence, development and reproduction at 0.02 micromol/g, and development and reproduction at 0.15 micromol/g for PCBz and FLU, respectively. Compared to residues associated with acute lethality, the most sensitive sublethal endpoints were approximately 4 and 60 times lower for PCBz and FLU, respectively. The relative consistency of the sublethal endpoints suggests that body residues can be a valuable tool to evaluate bioaccumulation data as part of a risk assessment to predict adverse effects to biota.

  13. Pairing behaviour and reproduction in Hyalella azteca as sensitive endpoints for detecting long-term consequences of pesticide pulses

    DEFF Research Database (Denmark)

    Pedersen, Signe; Palmqvist, Annemette; Thorbek, Pernille

    2013-01-01

    The aim of the present study was to examine acute and delayed effects of pulse exposure of the pyrethroid pesticide, permethrin, on precopulatory pairs of Hyalella azteca. Pairs of H. azteca were exposed to a single 1 h pulse of different nominal concentrations of permethrin: 0, 0.3, 0.9 or 2.7 μg....../L, but not 0.3 μg/L, compared to the control groups. The long-term effects of short-term exposure on reproductive behavior of pairs could potentially have consequences for the population dynamics of H. azteca. However, since individual-level responses can both overestimate and underestimate effects...

  14. Reference values for feeding parameters of isopods (Porcellioscaber, Isopoda, Crustacea).

    Science.gov (United States)

    Drobne, Damjana; Drobne, Samo

    2014-01-01

    The advantage of using terrestrial isopods in toxicity studies is that a battery of parameters can be tested at different levels of biological complexity. Feeding parameters for example link organism level response to potential ecological consequences but a problem with using feeding parameters in toxicity tests with terrestrial isopods is their high variability. The aim of our study was to set benchmark values for feeding parameters for isopod Porcellioscaber (Isopoda, Crustacea) in laboratory-controlled experiments. In the work presented here, the daily feeding rate of the central 50% of the control population of Porcellioscaber and a correlation between feeding rate and isopod weight were set. Values outside these ranges need additional evaluation to increase the relevance of test outcomes. We suggest using benchmark values for feeding parameters as well as the coefficient of variation (a) to identify animals with altered feeding parameters with respect to controls, and (b) to assess the data quality in each experiment.

  15. RNA interference with special reference to combating viruses of crustacea.

    Science.gov (United States)

    La Fauce, Kathy; Owens, Leigh

    2012-09-01

    RNA interference has evolved from being a nuisance biological phenomenon to a valuable research tool to determine gene function and as a therapeutic agent. Since pioneering observations regarding RNA interference were first reported in the 1990s from the nematode worm, plants and Drosophila, the RNAi phenomenon has since been reported in all eukaryotic organisms investigated from protozoans, plants, arthropods, fish and mammals. The design of RNAi therapeutics has progressed rapidly to designing dsRNA that can specifically and effectively silence disease related genes. Such technology has demonstrated the effective use of short interfering as therapeutics. In the absence of a B cell lineage in arthropods, and hence no long term vaccination strategy being available, the introduction of using RNA interference in crustacea may serve as an effective control and preventative measure for viral diseases for application in aquaculture.

  16. Survival, growth, and body residues of Hyalella azteca (Saussure) exposed to fipronil contaminated sediments from non-vegetated and vegetated microcosms

    Science.gov (United States)

    We assessed chronic effects of fipronil and metabolite contaminated sediments from non-vegetated and Thallia dealbata vegetated wetland microcosms on Hyalella azteca during wet and dry exposures. Mean sediment concentrations (ng g-1) ranged from 0.72-1.26, 0.01-0.69, 0.07-0.23, and 0.49-7.87 for fip...

  17. Chronic TiO2 nanoparticle exposure to a benthic organism, Hyalella azteca: Impact of solar UV radiation and material surface coatings on toxicity

    Science.gov (United States)

    The present study examined the chronic toxicity of TiO2 nanoparticles (nano-TiO2) to a representative benthic species, Hyalella azteca, using an industry standard, P25, and a coated nano-TiO2 used in commercial products. There is limited information on the chronic effects of nano...

  18. Chronic TiO2 nanoparticle exposure to a benthic organism, Hyalella azteca: Impact of solar UV radiation and material surface coatings on toxicity

    Science.gov (United States)

    The present study examined the chronic toxicity of TiO2 nanoparticles (nano-TiO2) to a representative benthic species, Hyalella azteca, using an industry standard, P25, and a coated nano-TiO2 used in commercial products. There is limited information on the chronic effects of nano...

  19. Single versus combined exposure of Hyalella azteca to zinc contaminated sediment and food.

    Science.gov (United States)

    Nguyen, Lien T H; Muyssen, Brita T A; Janssen, Colin R

    2012-03-01

    The amphipod Hyalella azteca was exposed for 28 d to different combinations of Zn contaminated sediment and food. Sediment exposure (+clean food) resulted in increased Zn body burdens, increased mortality and decreased body mass when the molar concentrations of simultaneously extracted Zn were greater than the molar concentration of Acid Volatile Sulfide (SEM(Zn)-AVS>0), suggesting that dissolved Zn was a dominant route of exposure. No adverse effect was noted in the food exposure (+clean sediment), suggesting selective feeding or regulation. Combined exposure (sediment+food) significantly increased adverse effects in comparison with sediment exposure, indicating contribution of dietary Zn to toxicity and bioaccumulation. The observed enhanced toxicity also supports the assumption on the presence of an avoidance/selective feeding reaction of the amphipods in the single sediment or food exposures. During 14 d post-exposure in clean medium, the organisms from the same combined exposure history received two feeding regimes, i.e. clean food and Zn spiked food. Elevated Zn bioaccumulation and reduced reproduction were noted in amphipods that were offered Zn spiked food compared to the respective organisms that were fed clean food. This was explained by the failure of avoidance/selective feeding behavior in the absence of an alternative food source (sediment), forcing the amphipods to take up Zn while feeding. Increasing Zn body burdens rejected the assumption that Zn uptake from food was regulated by H. azteca. Our results show that the selective feeding behavior should be accounted for when assessing ecological effects of Zn or other contaminants, especially when contaminated food is a potential exposure route.

  20. 10-Day survival of Hyalella azteca as a function of water quality parameters.

    Science.gov (United States)

    Javidmehr, Alireza; Kass, Philip H; Deanovic, Linda A; Connon, Richard E; Werner, Inge

    2015-05-01

    Estuarine systems are among the most impacted ecosystems due to anthropogenic contaminants; however, they present unique challenges to toxicity testing with regard to varying water quality parameters. The euryhaline amphipod species, Hyalella azteca, is widely used in toxicity testing and well suited for testing estuarine water samples. Nevertheless, the influence of relevant water quality parameters on test endpoints must be quantified in order to efficiently use this species for routine monitoring. Here, we studied the influence of five water quality parameters: electrical conductivity, pH, un-ionized ammonia, dissolved oxygen and temperature, on H. azteca survival in a water column toxicity test. A model was developed to quantify and predict the independent and interacting effects of water quality variables on 10-day survival. The model allows simultaneous assessment of multiple potential predictors recorded during the tests. Data used for modeling came from 1089 tests performed on ambient water samples over a period of three years (2006-2008). The final model reflects significant effects of predictors and their two-way interactions. The effect of each level of all predictors on survival probability of H. azteca was examined by comparing levels of each predictor at a time, while holding all others at their lowest (reference) level. This study showed that predictors of survival in water column tests should not be evaluated in isolation in the interpretation of H. azteca water column tests. Our model provides a useful tool to predict expected control survival based on relevant water quality parameters, and thus enables the use of H. azteca tests for toxicity monitoring in estuaries with a wide range of water quality conditions.

  1. Toxicity of sediment-associated pesticides to Chironomus dilutus and Hyalella azteca.

    Science.gov (United States)

    Ding, Yuping; Weston, Donald P; You, Jing; Rothert, Amanda K; Lydy, Michael J

    2011-07-01

    Two hundred sediment samples were collected and their toxicity evaluated to aquatic species in a previous study in the agriculturally dominated Central Valley of California, United States. Pyrethroid insecticides were the main contributors to the observed toxicity. However, mortality in approximately one third of the toxic samples could not be explained solely by the presence of pyrethroids in the matrices. Hundreds of pesticides are currently used in the Central Valley of California, but only a few dozen are analyzed in standard environmental monitoring. A significant amount of unexplained sediment toxicity may be due to pesticides that are in widespread use that but have not been routinely monitored in the environment, and even if some of them were, the concentrations harmful to aquatic organisms are unknown. In this study, toxicity thresholds for nine sediment-associated pesticides including abamectin, diazinon, dicofol, fenpropathrin, indoxacarb, methyl parathion, oxyfluorfen, propargite, and pyraclostrobin were established for two aquatic species, the midge Chironomus dilutus and the amphipod Hyalella azteca. For midges, the median lethal concentration (LC₅₀) of the pesticides ranged from 0.18 to 964 μg/g organic carbon (OC), with abamectin being the most toxic and propargite being the least toxic pesticide. A sublethal growth endpoint using average individual ash-free dry mass was also measured for the midges. The no-observable effect concentration values for growth ranged from 0.10 to 633 μg/g OC for the nine pesticides. For the amphipods, fenpropathrin was the most toxic, with an LC₅₀ of 1-2 μg/g OC. Abamectin, diazinon, and methyl parathion were all moderately toxic (LC₅₀s 2.8-26 μg/g OC). Dicofol, indoxacarb, oxyfluorfen, propargite, and pyraclostrobin were all relatively nontoxic, with LC₅₀s greater than the highest concentrations tested. The toxicity information collected in the present study will be helpful in decreasing the

  2. Assessment of the effect of water quality on copper toxicity in Hyalella azteca

    Energy Technology Data Exchange (ETDEWEB)

    Richards, L. [Univ. of Guelph, Guelph, Ontario (Canada); Walsh, S.; Shultz, C.; Stuart, M. [Canadian Nuclear Laboratories, Chalk River, Ontario (Canada)

    2015-06-15

    The objective of this study was to test the hypothesis that when standard artificial media 5-salt culture water (SAM-5S) is used to test sediment toxicity of much lower ionic-strength aquatic ecosystems, the resulting toxicity estimates are lower than if the tests had been conducted in water of comparable ionic strength. Results showed that this concern was unfounded for testing of copper toxicity to Hyalella azteca (H. azteca) in Ottawa River water. Sediment testing is often conducted using a standard water that is prepared in the laboratory. However, this water may have an ionic strength that is different than local water bodies. It follows that laboratory results using the standard water may be unrepresentative. A study was undertaken to assess the copper tolerance of 2 strains of H. azteca in SAM-5S, diluted SAM-5S (similar in electrical conductivity to Ottawa River water), and Ottawa River water. Acute (96 h) copper toxicity tests were conducted with 9-16 day-old H. azteca. For a given water type, the 2 strains of H. azteca yielded comparable responses to copper. The highest copper tolerance was found in Ottawa River water (closely followed by SAM-5S), whereas the lowest copper tolerance was found in diluted SAM-5S. Our results suggest that sediment toxicity is not lowered by the higher ionic strength of SAM-5S and that sediment toxicity tests of Ottawa River sediments, conducted with SAM-5S, can be used to estimate the in situ toxicity of the sediments. (author)

  3. A field assessment of long-term laboratory sediment toxicity tests with the amphipod Hyalella azteca

    Science.gov (United States)

    Ingersoll, Christopher G.; Wang, Ning; Hayward, Jeannie M. R.; Jones, John R.; Jones, Susan B.; Ireland, D. Scott

    2005-01-01

    Response of the amphipod Hyalella azteca exposed to contaminated sediments for 10 to 42 d in laboratory toxicity tests was compared to responses observed in controlled three-month invertebrate colonization exposures conducted in a pond. Sediments evaluated included a sediment spiked with dichlorodiphenyldichloroethane (DDD) or dilutions of a field sediment collected from the Grand Calumet River (GCR) in Indiana (USA) (contaminated with organic compounds and metals). Consistent effects were observed at the highest exposure concentrations (400 ??g DDD/goc [DDD concentrations normalized to grams of organic carbon (goc) in sedimentl or 4% GCR sediment) on survival, length, and reproduction of amphipods in the laboratory and on abundance of invertebrates colonizing sediments in the field. Effect concentrations for DDD observed for 10-d length and 42-d reproduction of amphipods (e.g., chronic value [ChV] of 66 ??g DDD/goc and 25% inhibition concentration [IC25] of 68 ??g DDD/goc for reproduction) were similar to the lowest effect concentrations for DDD measured on invertebrates colonizing sediment the field. Effect concentrations for GCR sediment on 28-d survival and length and 42-d reproduction and length of amphipods (i.e., ChVs of 0.20-0.66% GCR sediment) provided more conservative effect concentrations compared to 10-d survival or length of amphipods in the laboratory or the response of invertebrates colonizing sediment in the field (e.g., ChVs of 2.2% GCR sediment). Results of this study indicate that use of chronic laboratory toxicity tests with H. azteca and benthic colonization studies should be used to provide conservative estimates of impacts on benthic communities exposed to contaminated sediments. Bioaccumulation of DDD by oligochaetes colonizing the DDD-spiked sediment was similar to results of laboratory sediment tests previously conducted with the oligochaete Lumbriculus variegates, confirming that laboratory exposures can be used to estimate

  4. Chronic toxicity of the synthetic hormone 17alpha-ethinylestradiol to Chironomus tentans and Hyalella azteca.

    Science.gov (United States)

    Dussault, Eve B; Balakrishnan, Vimal K; Solomon, Keith R; Sibley, Paul K

    2008-12-01

    The chronic toxicity of the synthetic hormone 17alpha-ethinylestradiol (EE2) was investigated in two benthic invertebrates, the midge Chironomus tentans and the freshwater amphipod Hyalella azteca, in life-cycle water-only assays. In C. tentans, a 50% decrease in emergence was observed at a concentration of 1.5 mg/L; emergence was a more sensitive endpoint than survival, growth, or biomass. Reproduction was not significantly affected by EE2 exposure until a concentration of 3.1 mg/L, where emergence, and therefore reproduction, did not occur. In contrast, reproduction was the most sensitive endpoint in H. azteca (50% decrease in reproduction observed at a concentration of 0.36 mg/L). The sensitivity of the F1 generation to EE2 was also investigated with H. azteca, but was not different from the F0 generation. The data from the present study were combined with those from previous 10-d toxicity assays, to derive acute to chronic toxicity ratios (ACRs) for EE2. The ACRs calculated for EE2 were 13 for C. tentans and 16 for H. azteca, indicating that the application factors currently used in ecological risk assessment for the derivation of chronic toxicity are protective and conservative for these organisms. The results of the present study suggest that chronic toxicity was not mediated by disruption of endocrine pathways. Using a hazard quotient approach, the risk associated with sublethal exposure to EE2 was azteca and C. tentans, indicating that adverse effects are not expected, and that environmental exposure to EE2 likely poses a low risk to benthic invertebrates.

  5. Use of sublethal endpoints in sediment toxicity tests with the amphipod Hyalella azteca

    Science.gov (United States)

    Ingersoll, Chris G.; Brunson, Eric L.; Dwyer, F. James; Hardesty, Douglas K.; Kemble, Nile E.

    1998-01-01

    Short-term sediment toxicity tests that only measure effects on survival can be used to identify high levels of contamination but may not be able to identify marginally contaminated sediments. The objective of the present study was to develop a method for determining the potential sublethal effects of contaminants associated with sediment on the amphipod Hyalella azteca (e.g., reproduction). Exposures to sediment were started with 7- to 8-d-old amphipods. On day 28, amphipods were isolated from the sediment and placed in water-only chambers where reproduction was measured on day 35 and 42. Typically, amphipods were first in amplexus at about day 21 to 28 with release of the first brood between day 28 to 42. Endpoints measured included survival (day 28, 35, and 42), growth (as length and weight on day 28 and 42), and reproduction (number of young/female produced from day 28 to 42). This method was used to evaluate a formulated sediment and field-collected sediments with low to moderate concentrations of contaminants. Survival of amphipods in these sediments was typically >85% after the 28-d sediment exposures and the 14-d holding period in water to measure reproduction. Reproduction was more variable than growth; hence, more replicates might be needed to establish statistical differences among treatments. Previous studies have demonstrated that growth of H. azteca in sediment tests often provides unique information that can be used to discriminate toxic effects of exposure to contaminants. Either length or weight can be measured in sediment tests with H. azteca. However, additional statistical options are available if length is measured on individual amphipods, such as nested analysis of variance that can account for variance in length within replicates. Ongoing water-only studies testing select contaminants will provide additional data on the relative sensitivity and variability of sublethal endpoints in toxicity tests with H. azteca.

  6. Chronic toxicity of arsenic, cobalt, chromium and manganese to Hyalella azteca in relation to exposure and bioaccumulation

    Energy Technology Data Exchange (ETDEWEB)

    Norwood, W.P. [Department of Biology, University of Waterloo, Waterloo, ON N2L 3G1 (Canada) and Aquatic Ecosystems Protection Research Division, Environment Canada, P.O. Box 5050, Burlington, ON L7R 4A6 (Canada)]. E-mail: warren.norwood@ec.gc.ca; Borgmann, U. [Aquatic Ecosystems Protection Research Division, Environment Canada, P.O. Box 5050, Burlington, ON L7R 4A6 (Canada); Dixon, D.G. [Department of Biology, University of Waterloo, Waterloo, ON N2L 3G1 (Canada)

    2007-05-15

    Chronic toxicity of As, Co, Cr and Mn to Hyalella azteca can be described using a saturation-based mortality model relative to total-body or water metal concentration. LBC25s (total-body metal concentrations resulting in 25% mortality in 4 weeks) were 125, 103, 152 and 57,900 nmol g{sup -1} dry weight for As, Co, Cr and Mn respectively. LC50s (metal concentrations in water resulting in 25% mortality in 4 weeks) were 5600, 183, 731, and 197,000 nmol L{sup -1}, respectively. A hormesis growth response to As exposure was observed. Growth was a more variable endpoint than mortality for all four toxicants; however, confidence limits based on growth and mortality all overlapped, except Cr which had no effect on growth. Mn toxicity was greater in glass test containers compared to plastic. Bioaccumulation of As, Co, Cr, and Mn was strongly correlated with, and is useful for predicting, chronic mortality. - Chronic toxicity of As, Co, Cr and Mn to Hyalella azteca can be described using a saturation-based mortality model in relationship to total-body or water metal concentration.

  7. The common ecotoxicology laboratory strain of Hyalella azteca is genetically distinct from most wild strains sampled in eastern North America.

    Science.gov (United States)

    Major, Kaley; Soucek, David J; Giordano, Rosanna; Wetzel, Mark J; Soto-Adames, Felipe

    2013-11-01

    The amphipod Hyalella azteca is commonly used as a model for determining safe concentrations of contaminants in freshwaters. The authors sequenced the mitochondrial cytochrome c oxidase subunit I (COI) gene for representatives of 38 populations of this species complex from US and Canadian toxicology research laboratories and eastern North American field sites to determine their genetic relationships. With 1 exception, all US and Canadian laboratory cultures sampled were identified as conspecific. In 22 wild populations spanning 5 US states and 1 Canadian province, the commonly occurring laboratory species was found only in northern Florida, USA. Therefore, the diversity of the H. azteca species complex detected in the wild is not accurately represented in North American laboratories, questioning the reliability of H. azteca cultures currently in use to accurately predict the responses of wild populations in ecotoxicological assays. The authors also examined the utility of different COI nucleotide fragments presently in use to determine phylogenetic relationships in this group and concluded that saturation in DNA sequences leads to inconsistent relationships between clades. Amino acid sequences for COI were not saturated and may allow a more accurate phylogeny estimate. Hyalella azteca is crucial for developing water-quality regulations; therefore, laboratories should know and standardize the strain(s) they use to confidently compare toxicity tests across laboratories and determine whether they are an appropriate surrogate for their regions.

  8. Examining impacts of current-use pesticides in Southern Ontario using in situ exposures of the amphipod Hyalella azteca.

    Science.gov (United States)

    Bartlett, Adrienne J; Struger, John; Grapentine, Lee C; Palace, Vince P

    2016-05-01

    In situ exposures with Hyalella azteca were used to assess impacts of current-use pesticides in Southern Ontario, Canada. Exposures were conducted over 2 growing seasons within areas of high pesticide use: 1 site on Prudhomme Creek and 3 sites on Twenty Mile Creek. Three sites on Spencer Creek, an area of low pesticide use, were added in the second season. Surface water samples were collected every 2 wk to 3 wk and analyzed for a suite of pesticides. Hyalella were exposed in situ for 1 wk every 4 wk to 6 wk, and survival and acetylcholinesterase (AChE) activity were measured. Pesticides in surface waters reflected seasonal use patterns: lower concentrations in spring and fall and higher concentrations during summer months. Organophosphate insecticides (chlorpyrifos, azinphos methyl, diazinon) and acid herbicides (2,4-dichlorophenoxyacetic acid [2,4-D], mecoprop) were routinely detected in Prudhomme Creek, whereas neutral herbicides (atrazine, metolachlor) dominated the pesticide signature of Twenty Mile Creek. Spencer Creek contained fewer pesticides, which were measured at lower concentrations. In situ effects also followed seasonal patterns: higher survival and AChE activity in spring and fall, and lower survival and AChE activity during summer months. The highest toxicity was observed at Prudhomme Creek and was primarily associated with organophosphates. The present study demonstrated that current-use pesticides in Southern Ontario were linked to in situ effects and identified sites of concern requiring further investigation.

  9. Kinetics of uranium uptake in soft water and the effect of body size, bioaccumulation and toxicity to Hyalella azteca

    Energy Technology Data Exchange (ETDEWEB)

    Alves, L.C. [Department of Biology, University of Waterloo, Waterloo, ON N2L 3G1 (Canada); Aquatic Ecosystems Protection Research Division, Environment Canada, P.O. Box 5050, Burlington, ON L7R 4A6 (Canada); Borgmann, U. [Aquatic Ecosystems Protection Research Division, Environment Canada, P.O. Box 5050, Burlington, ON L7R 4A6 (Canada); Dixon, D.G., E-mail: dgdixon@uwaterloo.c [Department of Biology, University of Waterloo, Waterloo, ON N2L 3G1 (Canada)

    2009-08-15

    The kinetics of uptake and the effect of body size on uranium (U) bioaccumulation and toxicity to Hyalella azteca exposed to water-only U concentrations in soft water were evaluated. The effect of body size on U bioaccumulation was significant with a slope of -0.35 between log body concentration and log body mass. A saturation kinetic model was satisfactory to describe the uptake rate, elimination rate and the effect of gut-clearance on size-corrected U bioaccumulation in H. azteca. The one-week lethal water concentrations causing 50% mortality for juvenile and adult H. azteca were 1100 and 4000 nmol U/L, respectively. The one-week lethal body concentration causing 50% mortality was 140 nmol U/g for juvenile H. azteca and 220 nmol U/g for adult H. azteca. One-week bioaccumulation studies that properly account for body-size and gut-clearance times can provide valuable data on U bioavailability and toxicity in the environment. - Uranium accumulation by Hyalella azteca approaches steady state after one week but is strongly dependent on body size.

  10. Re-evaluation of metal bioaccumulation and chronic toxicity in Hyalella azteca using saturation curves and the biotic ligand model

    Energy Technology Data Exchange (ETDEWEB)

    Borgmann, U.; Norwood, W.P.; Dixon, D.G

    2004-10-01

    Bioaccumulation by Hyalella of all metals studied so far in our laboratory was re-evaluated to determine if the data could be explained satisfactorily using saturation models. Saturation kinetics are predicted by the biotic ligand model (BLM), now widely used in modelling acute toxicity, and are a pre-requisite if the BLM is to be applied to chronic toxicity. Saturation models provided a good fit to all the data. Since these are mechanistically based, they provide additional insights into metal accumulation mechanisms not immediately apparent when using allometric models. For example, maximum Cd accumulation is dependent on the hardness of the water to which Hyalella are acclimated. The BLM may need to be modified when applied to chronic toxicity. Use of saturation models for bioaccumulation, however, also necessitates the need for using saturation models for dose-response relationships in order to produce unambiguous estimates of LC50 values based on water and body concentrations. This affects predictions of toxicity at very low metal concentrations and results in lower predicted toxicity of mixtures when many metals are present at low concentrations.

  11. No Evidence for Temporal Variation in a Cryptic Species Community of Freshwater Amphipods of the Hyalella azteca Species Complex

    Directory of Open Access Journals (Sweden)

    Christian Nozais

    2011-08-01

    Full Text Available The co-occurrence of cryptic species of Hyalella amphipods is a challenge to our traditional views of how species assemble. Since these species have similar morphologies, it is not evident that they have developed phenotypic differences that would allow them to occupy different ecological niches. We examined the structure of a community of Hyalella amphipods in the littoral zone of a boreal lake to verify if temporal variation was present in relative abundances. Morphological and molecular analyses using the mitochondrial cytochrome c oxidase I (COI gene enabled us to detect three cryptic species at the study site. No temporal variation was observed in the community, as one cryptic species was always more abundant than the two others. The relative abundances of each species in the community appeared constant at least for the open-water season, both for adult and juvenile amphipods. Niche differences are still to be found among these species, but it is suggested that migration from nearby sites may be an important factor explaining the species co-occurrence.

  12. Changes in ventilation and locomotion of Gammarus pulex (Crustacea, Amphipoda) in response to low concentrations of pharmaceuticals

    NARCIS (Netherlands)

    Lange, de H.J.; Peeters, E.T.H.M.; Lürling, M.F.L.L.W.

    2009-01-01

    Exposure to contaminants below lethal concentrations may affect the performance of organisms, resulting in measurable differences in behavior. We measured the response of the benthic invertebrate Gammarus pulex (Crustacea, Amphipoda) to sublethal concentrations of three pharmaceuticals, fluoxetine,

  13. Reports on the impact of Caulerpa lentillifera by alien free-living isopod Paracerceis sculpta (Crustacea, Isopoda, Sphaeromatidae)

    National Research Council Canada - National Science Library

    太田, 悠造

    2014-01-01

    Unidentified free-living isopods (Crustacea, Sphaeromatidae) occurring in an important commercial seaweed bed of Caulerpa lentillifera at Miyako-jima island, southern Japan, are identified herein Paracerceis sculpta (Holmes, 1904...

  14. Distribution of Mysidium integrum (Tattersall) (Crustacea-mysidacea) in Venezuelan coral habitats

    NARCIS (Netherlands)

    Zoppi de Roa, Evelyn; Pedro Alonso, G.

    1997-01-01

    ZOPPI DE ROA, EVELYN & PEDRO ALONSO G.: Distribution of Mysidium integrum (Tattersall) (Crustacea: Mysidacea) in Venezuelan coral habitats. Studies Nat. Hist. Caribbean Region 73, Amsterdam 1997: 55-62. This paper reports the occurrence, distribution and some ecological aspects of mysids in six cora

  15. Phylogeny and evolution of life history strategies of the Parasitic Barnacles (Crustacea, Cirripedia, Rhizocephala)

    DEFF Research Database (Denmark)

    Glenner, Henrik; Hebsgaard, Martin Bay

    2006-01-01

    The barnacles (Crustacea, Cirripedia) consist of three well-defined orders: the conventional filter-feeding barnacles (Thoracica), the burrowing barnacles (Acrothoracica), and the parasitic barnacles (Rhizocephala). Thoracica and Acrothoracica feed by catching food particles from the surrounding ...... crustaceans (Anomura), which includes hermit crabs and squat lobsters....

  16. Hyloniscus riparius: een lang onopgemerkte landpissebed in Nederland (Crustacea, Isopoda: Trichoniscidae)?

    NARCIS (Netherlands)

    Wijnhoven, H.

    1993-01-01

    Hyloniscus riparius: an unnoticed terrestrial wood-louse in the Netherlands (Crustacea, Isopoda: Trichoniscidae) ? Until recently Hyloniscus riparius was only recorded from The Netherlands from green-houses in the Botanical Garden at Utrecht. More recently material was collected in the Ooy Polder. I

  17. Porcellium conspersum, een in Nederland zeer zeldzame landpissebed van vochtige bossen (Crustacea: Isopoda: Oniscoidea)

    NARCIS (Netherlands)

    Soesbergen, M.

    1999-01-01

    The influence of recent inundations on the distribution pattern of the isopod Eluma purpurascens in the province of Zeeland (Crustacea: Isopoda: Oniscoidea) Small scale mapping of Eluma purpurascens Budde-Lund, 1885 in the province of Zeeland revealed a remarkable distribution pattern. The species p

  18. Mysidacea (Crustacea) from the Minicoy lagoon (Lakshadweep, India) with description of a new species of Anisomysis

    Digital Repository Service at National Institute of Oceanography (India)

    Biju, A.; Panampunnayil, S.U.; Prabhakaran, M.P.

    .M.Garret, U.S.N. commanding, 27. Memoirs of the Museum of Comparative Zo?logy, Harvard College. 35: 175-296. Murano M. 1994. Anisomysis (Paranisomysis) ohtsukai (Crustacea, Mysidacea), a new mysid from Japan. Bulletin of National Science Museum, Tokyo 20...

  19. Immunocytochemical studies on the naupliar nervous system of Balanus improvisus (Crustacea, Cirripedia, Thecostraca)

    DEFF Research Database (Denmark)

    Semmler, Henrike; Wanninger, Andreas; Høeg, Jens T;

    2008-01-01

    neurons in the protocerebrum, along the circumoesophageal connectives and in the mandibular ganglion stain only for serotonin. Due to the almost complete absence of comparable data on the neuroanatomy of early (naupliar) stages in other Crustacea, we include immunocytochemical data on the larvae...

  20. Remarkable convergent evolution in specialized parasitic Thecostraca (Crustacea

    Directory of Open Access Journals (Sweden)

    Crandall Keith A

    2009-04-01

    Full Text Available Abstract Background The Thecostraca are arguably the most morphologically and biologically variable group within the Crustacea, including both suspension feeders (Cirripedia: Thoracica and Acrothoracica and parasitic forms (Cirripedia: Rhizocephala, Ascothoracida and Facetotecta. Similarities between the metamorphosis found in the Facetotecta and Rhizocephala suggests a common evolutionary origin, but until now no comprehensive study has looked at the basic evolution of these thecostracan groups. Results To this end, we collected DNA sequences from three nuclear genes [18S rRNA (2,305, 28S rRNA (2,402, Histone H3 (328] and 41 larval characters in seven facetotectans, five ascothoracidans, three acrothoracicans, 25 rhizocephalans and 39 thoracicans (ingroup and 12 Malacostraca and 10 Copepoda (outgroup. Maximum parsimony, maximum likelihood and Bayesian analyses showed the Facetotecta, Ascothoracida and Cirripedia each as monophyletic. The better resolved and highly supported DNA maximum likelihood and morphological-DNA Bayesian analysis trees depicted the main phylogenetic relationships within the Thecostraca as (Facetotecta, (Ascothoracida, (Acrothoracica, (Rhizocephala, Thoracica. Conclusion Our analyses indicate a convergent evolution of the very similar and highly reduced slug-shaped stages found during metamorphosis of both the Rhizocephala and the Facetotecta. This provides a remarkable case of convergent evolution and implies that the advanced endoparasitic mode of life known from the Rhizocephala and strongly indicated for the Facetotecta had no common origin. Future analyses are needed to determine whether the most recent common ancestor of the Thecostraca was free-living or some primitive form of ectoparasite.

  1. The evaluation of 3 diets for rearing Hyalella azteca and the influence of diet on acute ammonia toxicity.

    Science.gov (United States)

    Kennedy, Lisa M; Watson-Leung, Trudy L; Poirier, David G

    2016-10-01

    Three Hyalella azteca cultures were reared on different diets since birth, reflecting the recommended diets of various investigators. The 3 diets consisted of fish flakes (FF), a mixture of fish flakes supplemented with the diatom Thalassiosira weissflogii (FF-D), and a mixture of fish flakes supplemented with yeast, cereal grass media, and trout chow (FF-YCT). The 3 diets were evaluated by comparing 20 wk of culturing data, along with the organism's response to standard 96-h toxicity testing with ammonium chloride over a range of pH and temperature. Hyalella azteca fed the FF-D diet had the highest overall survival rate (96.6%, standard deviation [SD] 4.3%) compared to those fed the FF diet (92.0%, SD 12.7%), or the FF-YCT diet (91.1%, SD 14.8%), although difference in survival was not statistically significant. Organisms fed the FF-D diet produced a higher number of young per week per adult (6.1, SD 2.8) than the FF diet (5.1, SD 2.2), or the FF-YCT diet (4.0, SD 1.2), although differences were not statistically significant. Of the diets evaluated, H. azteca reared on the FF-D diet were often significantly more resistant to total and un-ionized ammonia toxicity in acute 96-h testing than those reared on the other 2 diets across the 2 temperatures and 5 pHs tested, suggesting this may be the most optimal diet for this species. Environ Toxicol Chem 2016;35:2416-2424. © 2016 SETAC.

  2. Causes of toxicity to Hyalella azteca in a stormwater management facility receiving highway runoff and snowmelt. Part I: polycyclic aromatic hydrocarbons and metals.

    Science.gov (United States)

    Bartlett, A J; Rochfort, Q; Brown, L R; Marsalek, J

    2012-01-01

    The Terraview-Willowfield Stormwater Management Facility (TWSMF) receives inputs of multiple contaminants, including metals, polycyclic aromatic hydrocarbons (PAHs), road salt, and nutrients, via highway and residential runoff. Contaminant concentrations in runoff are seasonally dependent, and are typically high in early spring, coinciding with the snowmelt. In order to investigate the seasonal fluctuations of contaminant loading and related changes in toxicity to benthic invertebrates, overlying water and sediment samples were collected in the fall and spring, reflecting low and high contaminant loading, respectively, and four-week sediment toxicity tests were conducted with Hyalella azteca. The effects of metals and PAHs are discussed here; the effects of salts, nutrients, and water quality are discussed in a companion paper. Survival and growth of Hyalella after exposure to fall samples were variable: survival was significantly reduced (64-74% of controls) at three out of four sites, but there were no significant growth effects. More dramatic effects were observed after Hyalella were exposed to spring samples: survival was significantly reduced at the two sites furthest downstream (0-75% of controls), and growth was significantly lower in four out of five sites when comparing Hyalella exposed to site sediment with overlying site water versus site sediment with overlying control water. These seasonal changes in toxicity were not related to metals or PAHs: 1. levels of bioavailable metals were below those expected to cause toxicity, and 2. levels of PAHs in sediment were lowest at sites with the greatest toxicity and highest in water and sediment at sites with no toxicity. Although not associated with toxicity, some metals and PAHs exceeded probable and severe effect levels, and could be a cause for concern if contaminant bioavailability changes. Toxicity in the TWSMF appeared to be primarily associated with water-borne contaminants. The cause(s) of these effects

  3. Relative toxicity of bifenthrin to Hyalella azteca in 10 day versus 28 day exposures.

    Science.gov (United States)

    Anderson, Brian S; Phillips, Bryn M; Voorhees, Jennifer P; Petersen, Megan A; Jennings, Lydia L; Fojut, Tessa L; Vasquez, Martice E; Siegler, Catherine; Tjeerdema, Ronald S

    2015-04-01

    Many watersheds in the Central Valley region of California are listed as impaired due to pyrethroid-associated sediment toxicity. The Central Valley Regional Water Quality Control Board is developing numeric sediment quality criteria for pyrethroids, beginning with bifenthrin. Criteria are being developed using existing data, along with data from 10 d and 28 d toxicity tests with Hyalella azteca conducted as part of the current study. A single range-finder and 2 definitive tests were conducted for each test duration. Median lethal concentrations (LC50s), as well as LC20s and inhibition concentrations (IC20s) were calculated based on measured whole sediment bifenthrin concentrations and interstitial water concentrations. Sediment LC50s were also corrected for organic C content. Average LC50s were not significantly different in 10 d versus 28 d tests with H. azteca: 9.1 and 9.6 ng/g bifenthrin for 10 d and 28 d tests, respectively. Average LC20 values were also similar with concentrations at 7.1 and 7.0 for 10 d and 28 d tests, respectively. Bifenthrin inhibition concentrations (IC20s) based on amphipod growth were variable, particularly in the 28 d tests, where a clear dose-response relationship was observed in only 1 of the definitive experiments. Average amphipod growth IC20s were 3.9 and 9.0 ng/g for 10 d and 28 d tests, respectively. Amphipod growth calculated as biomass resulted in IC20s of 4.1 and 6.3 ng/g for the 10 d and 28 d tests, respectively. Lack of a clear growth effect in the longer term test may be related to the lack of food adjustment to account for amphipod mortality in whole sediment exposures. The average C-corrected LC50s were 1.03 and 1.09 μg/g OC for the 10 d and 28 d tests, respectively. Interstitial water LC50s were determined as the measured dissolved concentration of bifenthrin relative to interstitial water dissolved organic carbon. The average LC50s for dissolved interstitial water bifenthrin were

  4. Identification of the first neuropeptides from the Amphipoda (Arthropoda, Crustacea).

    Science.gov (United States)

    Christie, Andrew E

    2014-09-15

    Despite being used as models in the field of ecotoxicology, including use in studies of endocrine disruption, little is known about the hormonal systems of amphipods, particularly their peptidergic signaling systems. Here, transcriptome shotgun assembly (TSA) sequences were used to predict the structures of the first neuropeptides from members of this crustacean order. Using a well-established workflow, BLAST searches of the extant amphipod TSA data were conducted for putative peptide-encoding transcripts. The pre/preprohormones deduced from the identified TSA sequences were then used to predict the mature structures of amphipod neuropeptides. In total, 43 putative peptide-encoding transcripts were identified from three amphipods, Echinogammarus veneris, Hyalella azteca and Melita plumulosa. Collectively, 139 distinct mature peptides (110 from E. veneris alone) were predicted from these TSA sequences. The identified peptides included members of the adipokinetic hormone/red pigment concentrating hormone, allatostatin A, allatostatin B, allatostatin C, bursicon α, bursicon β, crustacean hyperglycemic hormone, diuretic hormone 31, FLRFamide, molt-inhibiting hormone, myosuppressin, neuroparsin, neuropeptide F, orcokinin, pigment dispersing hormone (PDH), proctolin, RYamide, SIFamide, sulfakinin and tachykinin-related peptide families. Of particular note were the identifications of orcokinins possessing SFDEIDR- rather than the typical NFDEIDR- amino-termini, e.g. SFDEINRSNFGFN, a carboxyl-terminally amidated orcokinin, i.e. SFDEINRSNFGFSamide, PDHs longer than the stereotypical 18 amino acids, e.g. NSELLNTLLGSKSLAALRAAamide, and a 13 rather than 12 amino acid long SIFamide, i.e. GPYRKPPFNGSIFamide. These data not only provide the first descriptions of native amphipod neuropeptides, but also represent a new resource for initiating investigations of peptidergic signaling in the Amphipoda.

  5. Reference values for feeding parameters of isopods (Porcellio scaber, Isopoda, Crustacea)

    OpenAIRE

    Damjana Drobne; Samo Drobne

    2014-01-01

    Abstract The advantage of using terrestrial isopods in toxicity studies is that a battery of parameters can be tested at different levels of biological complexity. Feeding parameters for example link organism level response to potential ecological consequences but a problem with using feeding parameters in toxicity tests with terrestrial isopods is their high variability. The aim of our study was to set benchmark values for feeding parameters for isopod Porcellio scaber ( Isopoda , Crustacea ...

  6. Reference values for feeding parameters of isopods ( Porcellio scaber , Isopoda , Crustacea )

    OpenAIRE

    Damjana Drobne; Samo Drobne

    2014-01-01

    Abstract The advantage of using terrestrial isopods in toxicity studies is that a battery of parameters can be tested at different levels of biological complexity. Feeding parameters for example link organism level response to potential ecological consequences but a problem with using feeding parameters in toxicity tests with terrestrial isopods is their high variability. The aim of our study was to set benchmark values for feeding parameters for isopod Porcellio scaber ( Isopoda , Crustacea ...

  7. Spatial distribution and general population characteristics of Pseudanchialina pusilla (Crustacea: Mysida) in the eastern Arabian Sea

    Digital Repository Service at National Institute of Oceanography (India)

    Biju, A.

    in a fast maturation of the individuals, allowing the production of many generations per year. Due to continuous breeding, determining the number of generations becomes more complex (Mees et al., 1994; Delgado, 1997) because generations overlap...: Mysidacea) in a sand beach in south Brazil. Revista Brasileira de Zoologia, 25 (3): 403–412. 9 Delgado L., Guerao G. & Ribera C. 1997. Biolgy of the mysid Mesopodopsis slabberi (van Beneden, 1861) (Crustacea, Mysidacea) in a coastal lagoon of the Ebro...

  8. Macroepizoísmo em Libinia ferreirae (Crustacea, Brachyura, Majidae Macroepizoites on Libinia ferreirae (Crustacea, Brachyura, Majidae

    Directory of Open Access Journals (Sweden)

    Vanessa C. Winter

    2006-06-01

    Full Text Available Um estudo de distribuição dos macroepizóicos foi realizado numa população do caranguejo-aranha Libinia ferreirae Brito Capello, 1871 proveniente do litoral dos estados do Paraná e de Santa Catarina. O material biológico foi obtido junto aos pescadores, e faz parte do rejeito de pesca. Os caranguejos foram mensurados e os macroepizóicos identificados e contados. Os seguintes macroepizóicos sésseis foram registrados: Calliactis tricolor (Lesueur, 1817 (Cnidaria; Actiniaria (Cnidaria; Arca sp. (Mollusca; Ostreidae (Mollusca; Acanthodesia tenuis (Desor, 1848 (Bryozoa; Cirripedia e duas espécies tubícolas de Gammaridea (Crustacea. Além destes organismos ocorreram dois tubos desabitados e quatro animais vágeis. A anêmona C. tricolor foi a espécie mais abundante e freqüente, sendo, provavelmente, utilizada como mecanismo de camuflagem pelo caranguejo. O macroepizoísmo em L. ferreirae está relacionado com a idade ou tamanho do caranguejo, tendo maior incidência naqueles mais velhos ou de maior porte. Entretanto, a densidade dos macroepizóicos por caranguejo se mantém em torno de três. Não há relação entre o macroepizoísmo e o sexo do hospedeiro; somente fêmeas ovígeras utilizam desse recurso mais freqüentemente do que as não-ovígeras. Devido à maior área de fixação, os macroepizóicos colonizam principalmente a carapaça do caranguejo, enquanto nos pereiópodos há predominância de Bryozoa.A study of the distribution of the macroepizoites was carried out on a population of the spider crab Libinia ferreirae Brito Capello, 1871 from the Southern Brazilian coast. Crabs were obtained from shrimps and fishes by-catch. They were measured, and their macroepizoites were identified and counted. The following sessile macroepizoites were registered: Calliactis tricolor (Lesueur, 1817 (Cnidaria; Actiniaria (Cnidaria; Arca sp. (Mollusca; Ostreidae (Mollusca; Acanthodesia tenuis (Desor, 1848 (Bryozoa; Cirripedia and two species

  9. Calculation and evaluation of sediment effect concentrations for the amphipod Hyalella azteca and the midge Chironomus riparius

    Science.gov (United States)

    Ingersoll, Christopher G.; Haverland, Pamela S.; Brunson, Eric L.; Canfield, Timothy J.; Dwyer, F. James; Henke, Chris; Kemble, Nile E.; Mount, David R.; Fox, Richard G.

    1996-01-01

    Procedures are described for calculating and evaluating sediment effect concentrations (SECs) using laboratory data on the toxicity of contaminants associated with field-collected sediment to the amphipod Hyalella azteca and the midge Chironomus riparius. SECs are defined as the concentrations of individual contaminants in sediment below which toxicity is rarely observed and above which toxicity is frequently observed. The objective of the present study was to develop SECs to classify toxicity data for Great Lake sediment samples tested with Hyalella azteca and Chironomus riparius. This SEC database included samples from additional sites across the United States in order to make the database as robust as possible. Three types of SECs were calculated from these data: (1) Effect Range Low (ERL) and Effect Range Median (ERM), (2) Threshold Effect Level (TEL) and Probable Effect Level (PEL), and (3) No Effect Concentration (NEC). We were able to calculate SECs primarily for total metals, simultaneously extracted metals, polychlorinated biphenyls (PCBs), and polycyclic aromatic hydrocarbons (PAHs). The ranges of concentrations in sediment were too narrow in our database to adequately evaluate SECs for butyltins, methyl mercury, polychlorinated dioxins and furans, or chlorinated pesticides. About 60 to 80% of the sediment samples in the database are correctly classified as toxic or not toxic depending on type of SEC evaluated. ERMs and ERLs are generally as reliable as paired PELs and TELs at classifying both toxic and non-toxic samples in our database. Reliability of the SECs in terms of correctly classifying sediment samples is similar between ERMs and NECs; however, ERMs minimize Type I error (false positives) relative to ERLs and minimize Type II error (false negatives) relative to NECs. Correct classification of samples can be improved by using only the most reliable individual SECs for chemicals (i.e., those with a higher percentage of correct classification). SECs

  10. Genotype and toxicity relationships among Hyalella azteca: I. Acute exposure to metals or low pH

    Energy Technology Data Exchange (ETDEWEB)

    Duan, Y.; Guttman, S.I.; Oris, J.T.; Bailer, A.J.

    2000-05-01

    Comparative genotype and toxin interactions at three polymorphic enzyme loci were examined in a laboratory population of amphipods (Hyalella azteca) during acute exposure to cadmium, zinc, copper, lead, or low pH. Significant toxin-genotype interactions were observed using logistic regression to model mortality in ten of 15 analyses. Both stressor-specific and nonspecific modes of selection were observed. In general, low pH selected for different genotypes than those selected by metals, especially zinc. Different modes of selection were also observed when amphipods were exposed to different metals. These results suggest that exposure to low pH would significantly reduce the ability of H. azteca to survive subsequent contamination by metals; exposure to stressors in the reverse order would also compromise a population's chance of survival. A genetic distance analysis showed that the magnitude of genetic differentiation consistently increased among survivors compared with that of the initial populations. These increases in genetic divergence estimates suggest that acute exposure to metals or low pH may have an evolutionarily significant impact on the species. They also suggest that both genotype frequency and genetic distance measures (based on allozyme data) may be used as bioindicators for environmental monitoring programs. Validation of such bioindicators requires an understanding of the population's genetic background, genetic structure, and history.

  11. A comparison of the sublethal and lethal toxicity of four pesticides in Hyalella azteca and Chironomus dilutus.

    Science.gov (United States)

    Hasenbein, Simone; Connon, Richard E; Lawler, Sharon P; Geist, Juergen

    2015-08-01

    Laboratory toxicity testing is the primary tool used for surface water environmental risk assessment; however, there are critical information gaps regarding the sublethal effects of pesticides. In 10-day exposures, we assessed the lethal and sublethal (motility and growth) toxicities of four commonly used pesticides, bifenthrin, permethrin, cyfluthrin, and chlorpyrifos, on two freshwater invertebrates, Chironomus dilutus and Hyalella azteca. Pyrethroids were more toxic than the organophosphate chlorpyrifos in both species. Bifenthrin was most toxic to H. azteca survival and growth. Cyfluthrin was most toxic to C. dilutus. However, cyfluthrin had the greatest effect on motility on both H. azteca and C. dilutus. The evaluated concentrations of chlorpyrifos did not affect C. dilutus motility or growth, but significantly impacted H. azteca growth. Motility served as the most sensitive endpoint in assessing sublethal effects at low concentrations for both species, while growth was a good indicator of toxicity for all four pesticides for H. azteca. The integration of sublethal endpoints in ambient water monitoring and pesticide regulation efforts could improve identification of low-level pesticide concentrations that may eventually cause negative effects on food webs and community structure in aquatic environments.

  12. Single-walled carbon nanotubes toxicity to the freshwater amphipod Hyalella azteca: influence of sediment and exposure duration

    Directory of Open Access Journals (Sweden)

    Messika Revel

    2015-04-01

    Full Text Available Carbon nanomaterials are present in various industrial applications and therefore their release into the environment including freshwater ecosystem is expected to increase. The aim of the present study was to investigate the influence of several parameters on the toxicity of single-walled carbon nanotubes (SWCNT to the freshwater amphipod, Hyalella azteca. The effect of period of exposure, sediment presence and possible impurities released during SWCNT preparation on survival and/or growth of such organism was evaluated. We measured a reduction of survival at concentrations ranging from 10 to 40 mg/L after 96-h exposure, while no mortality was observed with the same concentrations and in the presence of artificial sediment after 14 days of exposure. It is possible that SWCNT are adsorbed on the organic matter from the artificial sediment leading to a decrease of SWCNT bioavailability. The survival and growth toxicity tests revealed a stronger effect at 28 days compared to the 14 days of exposure, and full mortality of organisms at 1000 mg/L for both exposure times. The presence of SWCNT in the gut of survived organisms was observed. The present study demonstrates that the interaction with sediment should be considered when carbon nanotubes toxicity through water exposure is investigated.

  13. Screening differentially expressed genes in an amphipod (Hyalella azteca) exposed to fungicide vinclozolin by suppression subtractive hybridization.

    Science.gov (United States)

    Wu, Yun H; Wu, Tsung M; Hong, Chwan Y; Wang, Yei S; Yen, Jui H

    2014-01-01

    Vinclozolin, a dicarboximide fungicide, is an endocrine disrupting chemical that competes with an androgenic endocrine disruptor compound. Most research has focused on the epigenetic effect of vinclozolin in humans. In terms of ecotoxicology, understanding the effect of vinclozolin on non-target organisms is important. The expression profile of a comprehensive set of genes in the amphipod Hyalella azteca exposed to vinclozolin was examined. The expressed sequence tags in low-dose vinclozolin-treated and -untreated amphipods were isolated and identified by suppression subtractive hybridization. DNA dot blotting was used to confirm the results and establish a subtracted cDNA library for comparing all differentially expressed sequences with and without vinclozolin treatment. In total, 494 differentially expressed genes, including hemocyanin, heatshock protein, cytochrome, cytochrome oxidase and NADH dehydrogenase were detected. Hemocyanin was the most abundant gene. DNA dot blotting revealed 55 genes with significant differential expression. These genes included larval serum protein 1 alpha, E3 ubiquitin-protein ligase, mitochondrial cytochrome c oxidase, mitochondrial protein, proteasome inhibitor, hemocyanin, zinc-finger-containing protein, mitochondrial NADH-ubiquinone oxidoreductase and epididymal sperm-binding protein. Vinclozolin appears to upregulate stress-related genes and hemocyanin, related to immunity. Moreover, vinclozolin downregulated NADH dehydrogenase, related to respiration. Thus, even a non-lethal concentration of vinclozolin still has an effect at the genetic level in H. azteca and presents a potential risk, especially as it would affect non-target organism hormone metabolism.

  14. Multiple origins of pyrethroid insecticide resistance across the species complex of a nontarget aquatic crustacean, Hyalella azteca.

    Science.gov (United States)

    Weston, Donald P; Poynton, Helen C; Wellborn, Gary A; Lydy, Michael J; Blalock, Bonnie J; Sepulveda, Maria S; Colbourne, John K

    2013-10-08

    Use of pesticides can have substantial nonlethal impacts on nontarget species, including driving evolutionary change, often with unknown consequences for species, ecosystems, and society. Hyalella azteca, a species complex of North American freshwater amphipods, is widely used for toxicity testing of water and sediment and has frequently shown toxicity due to pyrethroid pesticides. We demonstrate that 10 populations, 3 from laboratory cultures and 7 from California water bodies, differed by at least 550-fold in sensitivity to pyrethroids. The populations sorted into four phylogenetic groups consistent with species-level divergence. By sequencing the primary pyrethroid target site, the voltage-gated sodium channel, we show that point mutations and their spread in natural populations were responsible for differences in pyrethroid sensitivity. At least one population had both mutant and WT alleles, suggesting ongoing evolution of resistance. Although nonresistant H. azteca were susceptible to the typical neurotoxic effects of pyrethroids, gene expression analysis suggests the mode of action in resistant H. azteca was not neurotoxicity but was oxidative stress sustained only at considerably higher pyrethroid concentrations. The finding that a nontarget aquatic species has acquired resistance to pesticides used only on terrestrial pests is troubling evidence of the impact of chronic pesticide transport from land-based applications into aquatic systems. Our findings have far-reaching implications for continued uncritical use of H. azteca as a principal species for monitoring and environmental policy decisions.

  15. Bioaccumulation of metals by Hyalella azteca exposed to contaminated sediments from the upper Clark Fork River, Montana

    Science.gov (United States)

    Ingersoll, Christopher G.; Brumbaugh, William G.; Dwyer, F. James; Kemble, Nile E.

    1994-01-01

    Macroinvertebrates contaminated with metals in the Clark Fork River of Montana have been demonstrated to be a potentially toxic component in the diet of trout Because sediment was the suspected source of metals to these invertebrates, bioaccumulation of As, Cd, Cu, Pb, and Zn from sediment was evaluated by exposing the amphipod Hyalella azteca for 28 d in the laboratory to samples of sediment collected from depositional areas of the Clark Fork River Benthic invertebrates collected from riffles adjacent to the depositional areas were also analyzed for metals The pattern of metal accumulation between laboratory-exposed and field-collected animals was similar, however, the concentrations of metals in laboratory exposed amphipods were often 50 to 75% less than were the concentrations of metals in the field collected invertebrates These findings indicate that sediment is a significant source of metals to invertebrates in the Clark Fork River Additional studies should be conducted to determine threshold concentrations for effects of dietary metals on fish Long-term monitoring of the river should include sampling benthic invertebrates for metal accumulation.

  16. Contrasting effects of chloride on growth, reproduction, and toxicant sensitivity in two genetically distinct strains of Hyalella azteca.

    Science.gov (United States)

    Soucek, David J; Mount, David R; Dickinson, Amy; Hockett, J Russell; McEwen, Abigail R

    2015-10-01

    The strain of Hyalella azteca (Saussure: Amphipoda) commonly used for aquatic toxicity testing in the United States has been shown to perform poorly in some standardized reconstituted waters frequently used for other test species. In 10-d and 42-d experiments, the growth and reproduction of the US laboratory strain of H. azteca was shown to vary strongly with chloride concentration in the test water, with declining performance observed below 15 mg/L to 20 mg/L. In contrast to the chloride-dependent performance of the US laboratory strain of H. azteca, growth of a genetically distinct strain of H. azteca obtained from an Environment Canada laboratory in Burlington, Ontario, Canada, was not influenced by chloride concentration. In acute toxicity tests with the US laboratory strain of H. azteca, the acute toxicity of sodium nitrate increased with decreasing chloride in a pattern similar not only to that observed for control growth, but also to previous acute toxicity testing with sodium sulfate. Subsequent testing with the Burlington strain showed no significant relationship between chloride concentration and the acute toxicity of sodium nitrate or sodium sulfate. These findings suggest that the chloride-dependent toxicity shown for the US laboratory strain may be an unusual feature of that strain and perhaps not broadly representative of aquatic organisms as a whole.

  17. Bioassays with caged hyalella azteca to determine in situ toxicity downstream of two Saskatchewan, Canada, uranium operations.

    Science.gov (United States)

    Robertson, Erin L; Liber, Karsten

    2007-11-01

    The main objectives of this in situ study were to evaluate the usefulness of an in situ bioassay to determine if downstream water bodies at the Key Lake and Rabbit Lake uranium operations (Saskatchewan, Canada) were toxic to Hyalella azteca and, if toxicity was observed, to differentiate between the contribution of surface water and sediment contamination to in situ toxicity. These objectives were achieved by performing 4-d in situ bioassays with laboratory-reared H. azteca confined in specially designed, paired, surface water and sediment exposure chambers. Results from the in situ bioassays revealed significant mortality, relative to the respective reference site, at the exposure sites at both Key Lake (p azteca at both operations, although this relationship was stronger at Key Lake. At Key Lake, the primary cause of aquatic toxicity to H. azteca did not appear to be correlated with the variables measured in this study, but most likely with a pulse of organic mill-process chemicals released during the time of the in situ study-a transient event that was caused by a problem with the mill's solvent extraction process. The suspected cause of in situ toxicity to H. azteca at Rabbit Lake was high levels of uranium in surface water, sediment, and pore water.

  18. Survival and precopulatory guarding behavior of Hyalella azteca (Amphipoda) exposed to nitrate in the presence of atrazine.

    Science.gov (United States)

    Pandey, Ram B; Adams, Ginny L; Warren, Laurie W

    2011-05-01

    Nitrate is one of the most commonly detected contaminants found in aquatic systems with other pesticides such as atrazine. The current study examined potential combined effects of nitrate and atrazine on adults of the freshwater amphipod Hyalella azteca, using survival and precopulatory guarding behavior as toxic endpoints. Although significant differences in acute toxicity with nitrate alone and in binary combination with atrazine (200 µg/L) in water-only tests were not consistently observed for each time point, potential biologically relevant trends in the data were observed. Posttest growth and behavioral observations (10-day period) conducted after 96-hour exposure suggested that atrazine and nitrate at these concentrations did not result in delayed effects on H. azteca. However, when test conditions were modified from standard toxicity tests by feeding amphipods, nitrate was found to be more toxic, with a reduction in median lethal concentration (LC50) values of approximately 80%. We also demonstrated that nitrate exhibits a dose-response effect on precopulatory guarding behavior of H. azteca, suggesting that reproductive effects may occur at environmentally relevant concentrations.

  19. Influence of dissolved organic matter on nickel bioavailability and toxicity to Hyalella azteca in water-only exposures.

    Science.gov (United States)

    Doig, Lorne E; Liber, Karsten

    2006-03-10

    Dissolved organic matter (DOM) is known to reduce the bioavailability of metals in aquatic systems. This study evaluated the effects of DOM from various sources (e.g., Little Bear Lake sediment, Suwannee River, peat moss) and various DOM fractions (humic acids, HA; fulvic acids, FA) on the bioavailability of nickel (Ni) to Hyalella azteca, a common freshwater benthic invertebrate. In particular, this study was conducted to evaluate the effect of surficial sediment DOM on Ni bioavailability. Short-term (48 h) acute toxicity tests with H. azteca conducted in synthetic water demonstrated that the aqueous Ni concentrations required for lethality were greater than what could be significantly complexed by environmentally relevant concentrations of dissolved organic carbon (DOC: 0.6-30.4 mg/L). At Ni concentrations sublethal to H. azteca (500 microg/L), the bioavailability of Ni was significantly reduced in the presence of representative surface water DOC concentrations regardless of DOC source or fraction. DOC fraction (i.e., FA and HA) differentially affected Ni speciation, but had little or no effect on Ni accumulation by H. azteca. Tissue Ni was found to be strongly dependent upon the Ni(2+) concentration in the exposure solutions and the Ni:DOC ratio. Overall, the concentration of DOC played a greater role than either DOC source or fraction in determining Ni speciation and hence bioavailability and toxicity to H. azteca.

  20. Kinetics of uranium uptake in soft water and the effect of body size, bioaccumulation and toxicity to Hyalella azteca.

    Science.gov (United States)

    Alves, L C; Borgmann, U; Dixon, D G

    2009-01-01

    The kinetics of uptake and the effect of body size on uranium (U) bioaccumulation and toxicity to Hyalella azteca exposed to water-only U concentrations in soft water were evaluated. The effect of body size on U bioaccumulation was significant with a slope of -0.35 between log body concentration and log body mass. A saturation kinetic model was satisfactory to describe the uptake rate, elimination rate and the effect of gut-clearance on size-corrected U bioaccumulation in H. azteca. The one-week lethal water concentrations causing 50% mortality for juvenile and adult H. azteca were 1100 and 4000 nmol U/L, respectively. The one-week lethal body concentration causing 50% mortality was 140 nmol U/g for juvenile H. azteca and 220 nmol U/g for adult H. azteca. One-week bioaccumulation studies that properly account for body-size and gut-clearance times can provide valuable data on U bioavailability and toxicity in the environment.

  1. Comparative sensitivity of field and laboratory populations of Hyalella azteca to the pyrethroid insecticides bifenthrin and cypermethrin.

    Science.gov (United States)

    Clark, Stephen L; Ogle, R Scott; Gantner, Andrew; Hall, Lenwood W; Mitchell, Gary; Giddings, Jeffrey; McCoole, Matthew; Dobbs, Michael; Henry, Kevin; Valenti, Ted

    2015-10-01

    Hyalella azteca are epibenthic invertebrates that are widely used for toxicity studies. They are reported to be more sensitive to pyrethroid insecticides than most other test species, which has prompted considerable use of this species in toxicity testing of ambient surface waters where the presence of pyrethroids is suspected. However, resident H. azteca have been found in some ambient water bodies reported to contain surface water and/or sediment pyrethroid concentrations that are toxic to laboratory reared H. azteca. This observation suggests differences in the sensitivities of laboratory reared and field populations of H. azteca to pyrethroids. The goal of the present study was to determine the sensitivities of laboratory reared and field populations of H. azteca to the pyrethroids bifenthrin and cypermethrin. Specimens of H. azteca were collected from resident populations at field sites that are subject to varied land-use activities as well as from laboratory populations. These organisms were exposed to bifenthrin- or cypermethrin-spiked water in 96-h water-only toxicity tests. The resulting data demonstrated that: 1) field-collected populations in urban and agricultural settings can be >2 orders of magnitude less sensitive to the pyrethroids than laboratory reared organisms; 2) field-collected organisms varied in their sensitivity (possibly based on land-use activities), with organisms collected from undeveloped sites exhibiting sensitivities similar to laboratory reared organisms; and 3) the sensitivity of field-collected "tolerant" organisms increased in subsequent generations reared under laboratory conditions. Potential mechanisms for these differences are discussed.

  2. Oxidative stress induced in Hyalella azteca by an effluent from a NSAID-manufacturing plant in Mexico.

    Science.gov (United States)

    Novoa-Luna, Karen Adriana; Romero-Romero, Rubí; Natividad-Rangel, Reyna; Galar-Martínez, Marcela; SanJuan-Reyes, Nely; García-Medina, Sandra; Martínez-Vieyra, Catalina; Neri-Cruz, Nadia; Gómez-Oliván, Leobardo Manuel

    2016-09-01

    Production in the pharmaceutical industry has increased and along with it, the amount of wastewater of various characteristics and contaminant concentrations. The main chemicals in these effluents are solvents, detergents, disinfectants-such as sodium hypochlorite (NaClO)-and pharmaceutical products, all of which are potentially ecotoxic. Therefore, this study aimed to evaluate the oxidative stress induced in the amphipod Hyalella azteca by the effluent from a nonsteroidal anti-inflammatory drug (NSAID)-manufacturing plant. The median lethal concentration (72 h-LC50) was determined and H. azteca were exposed to the lowest observed adverse effect level (0.0732 %) for 12, 24, 48 and 72 h, and biomarkers of oxidative stress were evaluated [hydroperoxide content (HPC), lipid peroxidation (LPX), protein carbonyl content (PCC), and the activity of the superoxidant enzymes superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx)]. Statistically significant increases with respect to the control group (P azteca at all exposure times. Antioxidant enzymes activity SOD, CAT and GPx activity also increased significantly (P azteca.

  3. Assessing sediment toxicity from navigational pools of the Upper Mississippi River using a 28-day Hyalella azteca test

    Science.gov (United States)

    Kemble, N.E.; Brunson, E.L.; Canfield, T.J.; Dwyer, F.J.; Ingersoll, C.G.

    1998-01-01

    To assess the extent of sediment contamination in the Upper Mississippi River (UMR) system after the flood of 1993, sediment samples were collected from 24 of the 26 navigational pools in the river and from one site in the Saint Croix River in the summer of 1994. Whole-sediment tests were conducted with the amphipod Hyalella azteca for 28 days measuring the effects on survival, growth, and sexual maturation. Amphipod survival was significantly reduced in only one sediment (13B) relative to the control and reference sediments. Body length of amphipods was significantly reduced relative to the control and reference sediments in only one sample (26C). Sexual maturation was not significantly reduced in any treatment when compared to the control and reference sediments. No significant correlations were observed between survival, growth, and maturation to either the physical or chemical characteristics of the sediment samples from the river. When highly reliable effect range medians (ERMs) were used to evaluate sediment chemistry, 47 of 49 (96%) of the samples were correctly classified as nontoxic. These results indicate that sediment samples from the Upper Mississippi River are relatively uncontaminated compared to other areas of known contamination in the United States.

  4. TRACKING PYRETHROID TOXICITY IN SURFACE WATER SAMPLES: EXPOSURE DYNAMICS AND TOXICITY IDENTIFICATION TOOLS FOR LABORATORY TESTS WITH HYALELLA AZTECA (AMPHIPODA).

    Science.gov (United States)

    Deanovic, Linda A; Stillway, Marie; Hammock, Bruce G; Fong, Stephanie; Werner, Inge

    2017-09-09

    Pyrethroid insecticides are commonly used in pest control and are present at toxic concentrations in surface waters of agricultural and urban areas worldwide. Monitoring is challenging due to their high hydrophobicity and low toxicity thresholds, which often fall below the detection limits of analytical methods. Standard daphnid bioassays used in surface water monitoring are not sensitive enough to protect more susceptible invertebrate species such as the amphipod, Hyalella azteca, and chemical loss during toxicity testing is of concern. In this study, we quantified toxicity loss during storage and testing, using both natural and synthetic water, and present a tool to enhance toxic signal strength for improved sensitivity of H. azteca toxicity tests. The average half-life during storage in LDPE cubitainers at 4°C of five pyrethroids (permethrin, bifenthrin, lambda-cyhalothrin, cyfluthrin, esfenvalerate) and one organophosphate (chlorpyrifos; used as reference) was 1.4 d, and piperonyl butoxide (PBO) proved an effective tool to potentiate toxicity. We conclude that toxicity tests on ambient water samples containing these hydrophobic insecticides are likely to underestimate toxicity present in the field, and mimic short pulse rather than continuous exposures. Where these chemicals are of concern, the addition of PBO during testing can yield valuable information on their presence or absence. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

  5. Sex-specific nutrient use and preferential allocation of resources to a sexually selected trait in Hyalella amphipods.

    Science.gov (United States)

    Goos, Jared M; Cothran, Rickey D; Jeyasingh, Punidan D

    2016-03-01

    Although sexually dimorphic traits are often well studied, we know little about sex-specific resource use strategies that should underlie such dimorphism. We measured sex-specific responses in acquisition and assimilation of two fundamental resources, carbon (C) and phosphorus (P) in juvenile and mature Hyalella amphipods given low and high supplies of inorganic phosphate, analogous to oligotrophic and eutrophic conditions, respectively. Additionally, we quantified allocation of resources to sexual traits in males. Dual radiotracer ((14)C and (33)P) assays revealed substantial age- and sex-specific differences in acquisition and assimilation. Furthermore, a phenotypic manipulation experiment revealed that amphipods fed low-P food allocated more C to all traits than those fed high-P food. Importantly, we found that amphipods preferentially allocated more C to the development of a sexually selected trait (the posterior gnathopod), compared with a serially homologous trait (the fifth pereopod) not under sexual selection. Substantial differences in how the sexes use fundamental resources, and the impact of altered nutrient supply on such differences, illuminate sexual dimorphism at the lowest level of biological organization. Such information will be important in understanding how sex- and age-specific life history demands influence nutrient processing in a biosphere characterized by rapidly changing alterations to biogeochemical cycles.

  6. Comparação metodológica de testes de toxicidade com Hyalella azteca (Crustacea, Amphipoda) e avaliação da qualidade do sedimento em reservatórios do rio Tietê (SP)

    OpenAIRE

    Ana Paula Cristiano do Nascimento

    2003-01-01

    O presente trabalho fez parte do Projeto QualiSed, uma cooperação entre UFSCar, Unicamp e Cetesb, o qual realizou um levantamento das bases técnico-científicas para a derivação de critérios de qualidade de sedimentos (CQS) para proteção da fauna aquática dos ecossistemas. Nos últimos anos tem havido um grande interesse no desenvolvimento, aperfeiçoamento e aplicação de metodologias para avaliar o grau de contaminação de sedimentos. Estes, apesar de fornecerem habitat para muitos organismos aq...

  7. Causes of toxicity to Hyalella azteca in a stormwater management facility receiving highway runoff and snowmelt. Part II: salts, nutrients, and water quality.

    Science.gov (United States)

    Bartlett, A J; Rochfort, Q; Brown, L R; Marsalek, J

    2012-01-01

    The Terraview-Willowfield Stormwater Management Facility (TWSMF) features a tandem of stormwater management ponds, which receive inputs of multiple contaminants from highway and residential runoff. Previous research determined that benthic communities in the ponds were impacted by poor habitat quality, due to elevated sediment concentrations of metals and polycyclic aromatic hydrocarbons (PAHS), and salinity in the overlying water, but did not address seasonal changes, including those caused by the influx of contaminants with the snowmelt. In order to address this issue, water and sediment samples were collected from the TWSMF during the fall and spring, and four-week sediment toxicity tests were conducted with Hyalella azteca. The effects of metals and PAHs are discussed in a companion paper; the effects of road salt, nutrients, and water quality are discussed here. After exposure to fall samples, survival of Hyalella was reduced (64-74% of controls) at three out of four sites, but growth was not negatively affected. After exposure to spring samples, survival was 0-75% of controls at the two sites furthest downstream, and growth was significantly lower in four out of five sites when comparing Hyalella exposed to site water overlying site sediment versus control water overlying site sediment. Toxicity appeared to be related to chloride concentrations: little or no toxicity occurred in fall samples (200 mg Cl(-)/L), and significant effects on survival and growth occurred in spring samples above 1550 mg Cl(-)/L and 380 mg Cl(-)/L, respectively. Sodium chloride toxicity tests showed similar results: four-week LC50s and EC25s (growth) were 1200 and 420 mg Cl(-)/L, respectively. Although water quality and nutrients were associated with effects observed in the TWSMF, chloride from road salt was the primary cause of toxicity in this study. Chloride persists during much of the year at concentrations representing a significant threat to benthic communities in the TWSMF.

  8. Typtonomenaeusformosanus gen. et sp. nov., a new sponge-associated pontoniine shrimp (Crustacea: Decapoda: Palaemonidae: Pontoniinae) from northern Taiwan.

    Science.gov (United States)

    Marin, Ivan; Chan, Tin-Yam

    2013-01-01

    A new genus and species of sponge-associated pontoniine shrimps (Crustacea: Decapoda: Palaemonidae: Pontoniinae) is described from northern part of Formosa Island (Taiwan). The new species can be clearly recognized by convex robust nail-like apices on dactyli of both pereiopods II--a unique morphological structure among pontoniine shrimps. Morphological differences from all known sponge-associated pontoniine genera are discussed.

  9. A new species of Hemicyclops (Crustacea, Copepoda, Poecilostomatoida, Clausidiidae) associated with hermit crabs in Curaçao

    NARCIS (Netherlands)

    Stock, Jan H.

    1992-01-01

    STOCK, J. H. 1992. A new species of Hemicyclops (Crustacea, Copepoda, Poecilostomatoida, Clausidiidae) associated with hermit crabs in Curaçao. Stud. Nat. Hist. Caribbean Region 71, Amsterdam 1992: 69-78. Hemicyclops geminatus n. sp. is described from the upper infralittoral zone of Curaçao (Antille

  10. On a collection of Decapod and Stomatopod Crustacea from Pulau Berhala, an islet situated in the straits of Malacca

    NARCIS (Netherlands)

    Man, de J.G.

    1929-01-01

    Mr. J. C. VAN DER MEER MOHR, Zoologist at the Deli-Station at Medan (Sumatra), has in 1926 and in August and December 1927 collected at Pulau Berhala 37 species and one variety of Decapod Crustacea and a variety of Gonodactylus chiragra (Fabr.); these species are described in this paper. As far as I

  11. Endemism in the Cladocera (Crustacea: Branchiopoda of Southern Africa

    Directory of Open Access Journals (Sweden)

    Kay Van Damme

    2013-08-01

    Full Text Available We review the current state of knowledge and patterns of distribution in the endemic Cladocera (Crustacea: Branchiopoda of Southern Africa and describe two species of the Western Cape, of which one is new to science. Frey (1993, Korovchinsky (2006 and Smirnov (2008 previously suggested that South Africa harbours few endemics in the Cladocera. In the current study, we show that so-called low endemism in this region is mainly attributed to our limited state of knowledge of the local cladoceran fauna. Many of the South African taxa are ignored and revisions are lacking, as we briefly discuss for the genus Daphnia. We list known Southern African endemic Cladocera with notes on their status, map the distributions of well-studied taxa, and discuss the importance of temporary freshwater rockpools. We confirm that Southern Africa is a region of endemism for the group. We recognise three categories of endemics: i Montane endemics in the East (e.g. Drakensberg mountains; ii endemics of the Western Cape (lowlands; iii South African endemics, widely distributed in the region, both in the mountains and the lowlands. South African endemics have previously been regarded as relicts (Korovchinsky 2006, yet for the two taxa explored in detail in this study, there are no specific primitive morphological characters in comparison to congeners (within their respective genus/species group and the morphology mainly suggests strong isolation. The two species belong to the Chydoridae and the Eurycercidae, respectively, and are used here as case studies for the investigation of Western Cape endemics. The first, Alona capensis Rühe, 1914 (Anomopoda: Chydoridae: Aloninae, is redescribed based on the type material. We discuss the affinities of this enigmatic species for the first time. Morphology of the habitus and the postabdomen parallel that of members of the Alona affinis-complex. The disconnected head pores and limb characters, on the other hand, place A. capensis in

  12. OCORRÊNCIA DE Macrobrachium amazonicum (CRUSTACEA, DECAPODA) NA DIETA DE Lysapsus bolivianus (ANURA, HYLIDAE).

    OpenAIRE

    Mayara Fabiana Melo Furtado; Carlos Eduardo Costa-Campos; Suelique de Souza Queiroz; Kelly Juliana Gaya Correa; Inacia Maria Vieira

    2013-01-01

    A dieta de Lysapsus bolivianus está baseada principalmente em pequenos artrópodes, representados geralmente por Diptera, Collembola e Hemiptera, sendo os crustáceos encontrados ocasionalmente. No presente trabalho registramos a presença de Macrobrachium amazonicum na dieta de L. bolivianus em planície de Inundação no Norte do Brasil. Palavras-chave: dieta, Crustacea, Amazônia Oriental. DOI: http://dx.doi.org/10.18561/2179-5746/biotaamazonia.v3n3p185-187

  13. Organization of the mitochondrial genome of mantis shrimp Pseudosquilla ciliata (Crustacea: Stomatopoda).

    Science.gov (United States)

    Podsiadlowski, Lars; Bartolomaeus, Thomas

    2005-01-01

    We determined the nearly complete mitochondrial genome of Pseudosquilla ciliata (Crustacea, Stomatopoda), including all protein-coding genes and all but one of the transfer RNAs. There were no gene rearrangements relative to the pattern shared by crustaceans and hexapods. Phylogenetic analysis using concatenated amino acid sequences of the mitochondrial protein-coding genes confirmed a basal position of Stomatopoda among Eumalacostraca. Pancrustacean relationships based on mitogenomic data were analyzed and are discussed in relation to crustacean and hexapod monophyly and hexapod affinities to crustacean subtaxa.

  14. Ephemeroporus quasimodo sp. nov. (Crustacea: Cladocera: Chydoridae), a new species from the Brazilian Cerrado.

    Science.gov (United States)

    Elmoor-Loureiro, Lourdes M A

    2014-06-19

    A new species of Chydoridae cladoceran (Crustacea: Cladocera: Chydoridae) is described from the Cerrado (a Brazilian tropical savanna ecoregion), Central Brazil. Ephemeroporus quasimodo sp. nov. differs from other species of the genus in a high dorsal keel on carapace and posterior part of the head shield, which resembles a hunchback. Parthenogenetic females, ephippial females and males are described, including details of trunk limb morphology. The species is endemic to shallow wetlands found in the Cerrado, where pristine conditions are preserved. Some questions on genus morphology and taxonomic status of Ephemeroporus species occurring in Brazil are discussed.

  15. [A new species of amphipod crustacean of the genus Amphilochus (Crustacea, Amphipoda, Amphilochidae) from Venezuela].

    Science.gov (United States)

    Martín, A; Ortiz, M; Atienza, D

    2001-01-01

    A new species of amphipod Crustacea (Gammaridea, Amphilochidae) of the genus Amphilochus Bate, 1862, is described. The species was collected in Phallusia nigra (Savigny, 1816) at depths between 0 and 2 m, in the pier piles of the Marina El Ancla and Los Manglares gas station in Morrocoy National Park (Falcón State, Venezuela), during the months of June and July 1998. The main differences between A. ascidicola new species and all others species of the genus recorded from the Gulf of Mexico and the Caribbean Sea, are given.

  16. First Record of Hippa adactyla (Fabricius, 1787; Crustacea, Anomura, Hippidae) from Indonesian Waters.

    Science.gov (United States)

    Ardika, Puji Utari; Farajallah, Achmad; Wardiatno, Yusli

    2015-12-01

    Specimens of Hippa adactyla (Crustacea, Anomura, Hippidae) were collected from several coasts of Indonesia (Sumatera, Java, Bali-Lombok and Sulawesi). This finding represents the first record of this species in Indonesia and confirms its presence in the Indian Ocean and in the Wallacea region. Its systematic and morphological characteristics are described, and its distribution in Indonesia is presented. One of the main characteristics of this species is a median lobe in the anterior part of the carapace, which has 3-4 lobes. Likewise, the left antenna has 2-6 articles.

  17. An evaluation of the ability of chemical measurements to predict polycyclic aromatic hydrocarbon-contaminated sediment toxicity to Hyalella azteca.

    Science.gov (United States)

    McDonough, Kathleen M; Azzolina, Nicholas A; Hawthorne, Steven B; Nakles, David V; Neuhauser, Edward F

    2010-07-01

    The present study examined the ability of three chemical estimation methods to predict toxicity and nontoxicity of polycyclic aromatic hydrocarbon (PAH) -contaminated sediment to the freshwater benthic amphipod Hyalella azteca for 192 sediment samples from 12 field sites. The first method used bulk sediment concentrations of 34 PAH compounds (PAH34), and fraction of total organic carbon, coupled with equilibrium partitioning theory to predict pore-water concentrations (KOC method). The second method used bulk sediment PAH34 concentrations and the fraction of anthropogenic (black carbon) and natural organic carbon coupled with literature-based black carbon-water and organic carbon-water partition coefficients to estimate pore-water concentrations (KOCKBC method). The final method directly measured pore-water concentrations (pore-water method). The U.S. Environmental Protection Agency's hydrocarbon narcosis model was used to predict sediment toxicity for all three methods using the modeled or measured pore-water concentration as input. The KOC method was unable to predict nontoxicity (83% of nontoxic samples were predicted to be toxic). The KOCKBC method was not able to predict toxicity (57% of toxic samples were predicted to be nontoxic) and, therefore, was not protective of the environment. The pore-water method was able to predict toxicity (correctly predicted 100% of the toxic samples were toxic) and nontoxicity (correctly predicted 71% of the nontoxic samples were nontoxic). This analysis clearly shows that direct pore-water measurement is the most accurate chemical method currently available to estimate PAH-contaminated sediment toxicity to H. azteca.

  18. Pairing behavior and reproduction in Hyalella azteca as sensitive endpoints for detecting long-term consequences of pesticide pulses.

    Science.gov (United States)

    Pedersen, Signe; Palmqvist, Annemette; Thorbek, Pernille; Hamer, Mick; Forbes, Valery

    2013-11-15

    The aim of the present study was to examine acute and delayed effects of pulse exposure of the pyrethroid pesticide, permethrin, on precopulatory pairs of Hyalella azteca. Pairs of H. azteca were exposed to a single 1h pulse of different nominal concentrations of permethrin: 0, 0.3, 0.9 or 2.7 μg/L. During exposure, pairing behavior was observed, and during a 56 day post-exposure period the treatments were monitored for pairing behavior, survival and reproductive output. All permethrin-exposed pairs separated within minutes during exposure and shortly thereafter became immobile; however they regained mobility after transfer to clean water. The time to re-form pairs was significantly longer in all tested concentrations compared to the control, although all surviving pairs re-formed within the 56 day test period. Nevertheless not all pairs exposed to 0.9 and 2.7 μg/L reproduced. Furthermore the numbers of juveniles produced by pairs exposed to 0.9 and 2.7 μg/L, but not 0.3 μg/L, were lower throughout the entire post-exposure period compared to the control groups, and the total numbers of juveniles produced during 56 days were significantly lower in organisms exposed to 0.9 and 2.7 μg/L, but not 0.3 μg/L, compared to the control groups. The long-term effects of short-term exposure on reproductive behavior of pairs could potentially have consequences for the population dynamics of H. azteca. However, since individual-level responses can both overestimate and underestimate effects at the population level, appropriate population models are needed to reduce the uncertainty in extrapolating between these levels of biological organization.

  19. Toxicity of fluorotelomer carboxylic acids to the algae Pseudokirchneriella subcapitata and Chlorella vulgaris, and the amphipod Hyalella azteca.

    Science.gov (United States)

    Mitchell, Rebecca J; Myers, Anne L; Mabury, Scott A; Solomon, Keith R; Sibley, Paul K

    2011-11-01

    Perfluorinated acids (PFAs) have elicited significant global regulatory and scientific concern due to their persistence and global pervasiveness. A source of PFAs in the environment is through degradation of fluorotelomer carboxylic acids (FTCAs) but little is known about the toxicity of these degradation products. Previous work found that FTCAs were two to three orders of magnitude more toxic to some freshwater invertebrates than their PFA counterparts and exhibited comparable chain-length-toxicity relationships. In this study, we investigated the toxicity of the 6:2, 8:2, and 10:2 saturated (FTsCA) and unsaturated (FTuCA) fluorotelomer carboxylic acids to two species of freshwater algae, Chlorella vulgaris and Pseudokirchneriella subcapitata, and the amphipod, Hyalella azteca. C. vulgaris was generally the most sensitive species, with EC₅₀s of 26.2, 31.8, 11.1, and 4.2 mg/L for the 6:2 FTsCA, 6:2 FTuCA, 8:2 FTuCA, and 10:2 FTsCA, respectively. H. azteca was most sensitive to the 8:2 FTsCA and 10:2 FTuCA, with LC₅₀s of 5.1 and 3.7 mg/L. The toxicity of the FTCAs generally increased with increasing carbon chain length, and with saturation for most of the species tested, with the exception of P. subcapitata, which did not exhibit any trend. These observations agree with chain-length-toxicity relationships previously reported for the PFCAs and support the greater toxicity of the FTCAs compared to PFCAs. However, the toxicity values are approximately 1000-fold above those detected in the environment indicating negligible risk to aquatic invertebrates.

  20. Bioaccumulation of the synthetic hormone 17alpha-ethinylestradiol in the benthic invertebrates Chironomus tentans and Hyalella azteca.

    Science.gov (United States)

    Dussault, Eve B; Balakrishnan, Vimal K; Borgmann, Uwe; Solomon, Keith R; Sibley, Paul K

    2009-09-01

    The present study investigated the bioaccumulation of the synthetic hormone 17alpha-ethinylestradiol (EE2) in the benthic invertebrates Chironomus tentans and Hyalella azteca, in water-only and spiked sediment assays. Water and sediment residue analysis was performed by LC/MS-MS, while biota extracts were analyzed using both LC/MS-MS and a recombinant yeast estrogen receptor assay. At the lowest exposure concentration, C. tentans accumulated less EE2 than H. azteca in the water-only assays (p=0.0004), but due to different slopes, this difference subsided with increasing concentrations; at the exposure concentration of 1mg/L, C. tentans had a greater body burden than H. azteca (p=0.02). In spiked sediments, C. tentans had the greatest EE2 accumulation (1.2+/-0.14 vs. 0.5+/-0.05 microg/gdw, n=4). Measurements in H. azteca indicated a negligible contribution from the sediments to the uptake of EE2 in this species. These differences were likely due to differences in the behavior and life history of the two species (epibenthic vs. endobenthic). Water-only bioaccumulation factors (BAFs) calculated at the lowest exposure concentration were significantly smaller in C. tentans than in H. azteca (31 vs. 142, respectively; pazteca (0.8 vs. 0.3; p<0.0001). Extracts of the exposed animals caused a response in a recombinant yeast estrogen receptor assay, thus confirming the estrogenic activity of the samples, presumably from EE2 and its estrogenic metabolites. The results of the present study suggest that consumption of invertebrate food items could provide an additional source of exposure to estrogenic substances in vertebrate predators.

  1. Fish and land use influence Gammarus lacustris and Hyalella azteca (Amphipoda) densities in large wetlands across the upper Midwest

    Science.gov (United States)

    Anteau, Michael J.; Afton, Alan D.; Anteau, Andrea C.E.; Moser, E. Barry

    2011-01-01

    Gammarus lacustrisK/i> and Ki>Hyalella azteca (hereafter G. lacustris and H. azteca, respectively) are important components of secondary production in wetlands and shallow lakes of the upper Midwest, USA. Within the past 50 years, amphipod densities have decreased while occurrences of fish and intensity of agricultural land use have increased markedly across this landscape. We investigated influences of fish, sedimentation, and submerged aquatic vegetation (SAV) on densities of G. lacustris and H. azteca in semipermanent and permanent wetlands and shallow lakes (n = 283) throughout seven eco-physiographic regions of Iowa, Minnesota, and North Dakota during 2004–2005. G. lacustris and H. azteca densities were positively correlated with densities of SAV (P P P = 0.01 and P = 0.013, respectively) and with high densities of fathead minnows (Pimephales promelas; P P = 0.033, respectively). H. azteca densities also were negatively correlated with densities of small fish (e.g., other minnows [Cyprinidae] and sticklebacks [Gasterosteidae]; P = 0.048) and common carp (Cyprinus spp.; P = 0.022). G. lacustris densities were negatively correlated with high levels of suspended solids (an index for sedimentation; P H. azteca densities were positively correlated with the width of upland-vegetation buffers (P = 0.004). Our results indicate that sedimentation and fish reduce amphipod densities and may contribute to the current low densities of amphipods in the upper Midwest. Thus, removing/excluding fish, and providing a thick buffer of upland vegetation around wetlands may help restore amphipod densities and wetland and water quality within this landscape.

  2. Evaluation of ability of reference toxicity tests to identify stress in laboratory populations of the amphipod Hyalella azteca

    Science.gov (United States)

    McNulty, E.W.; Dwyer, F.J.; Ellersieck, Mark R.; Greer, E.I.; Ingersoll, C.G.; Rabeni, C.F.

    1999-01-01

    Standard methods for conducting toxicity tests imply that the condition of test organisms can be established using reference toxicity tests. However, only a limited number of studies have evaluated whether reference toxicity tests can actually be used to determine if organisms are in good condition at the start of a test. We evaluated the ability of reference toxicants to identify stress associated with starvation in laboratory populations of the amphipod Hyalella azteca using acute toxicity tests and four reference toxicants: KCl, CdCl2, sodium pentachlorophenate (NaPCP), and carbaryl. Stress associated with severe starvation was observed with exposure of amphipods to carbaryl or NaPCP but not with exposure to KCl or CdCl2 (i.e., lower LC50 with severe starvation). Although the LC50s for NaPCP and carbaryl were statistically different between starved and fed amphipods, this difference may not be biologically significant given the variability expected in acute lethality tests. Stress associated with sieving, heat shock, or cold shock of amphipods before the start of a test was not evident with exposure to carbaryl or KCl as reference toxicants. The chemicals evaluated in this study provided minimal information about the condition of the organisms used to start a toxicity test. Laboratories should periodically perform reference toxicity tests to assess the sensitivity of life stages or strains of test organisms. However, use of other test acceptability criteria required in standard methods such as minimum survival, growth, or reproduction of organisms in the control treatment at the end of a test, provides more useful information about the condition of organisms used to start a test compared to data generated from reference toxicity tests.

  3. Greatly reduced bioavailability and toxicity of polycyclic aromatic hydrocarbons to Hyalella azteca in sediments from manufactured-gas plant sites.

    Science.gov (United States)

    Kreitinger, Joseph P; Neuhauser, Edward F; Doherty, Francis G; Hawthorne, Steven B

    2007-06-01

    The toxicity of polycyclic aromatic hydrocarbons (PAHs) to Hyalella azteca, was measured in 34 sediment samples collected from four manufactured-gas plant (MGP) sites ranging in total PAH16 (sum of 16 U.S. Environmental Protection Agency priority pollutant PAHs) concentrations from 4 to 5700 mg/kg, total organic carbon content from 0.6 to 11%, and soot carbon from 0.2 to 5.1%. The survival and growth of H. azteca in 28-d bioassays were unrelated to total PAH concentration, with 100% survival in one sediment having 1,730 mg/kg total PAH16, whereas no survival was observed in sediment samples with concentrations as low as 54 mg/kg total PAH16. Twenty-five of the 34 sediment samples exceeded the probable effects concentration screening value of 22.8 mg/kg total PAH13 (sum of 13 PAHs) and equilibrium partitioning sediment benchmarks for PAH mixtures (on the basis of the measurement of 18 parent PAHs and 16 groups of alkylated PAHs, [PAH34]); yet, 19 (76%) of the 25 samples predicted to be toxic were not toxic to H. azteca. However, the toxicity of PAHs to H. azteca was accurately predicted when either the rapidly released concentrations as determined by mild supercritical fluid extraction (SFE) or the pore-water concentrations were used to establish the bioavailability of PAHs. These results demonstrate that the PAHs present in many sediments collected from MGP sites have low bioavailability and that both the measurement of the rapidly released PAH concentrations with mild SFE and the dissolved pore-water concentrations of PAHs are useful tools for estimating chronic toxicity to H. azteca.

  4. Toxicity of sediment cores collected from the ashtabula river in northeastern Ohio, USA, to the amphipod hyalella azteca

    Science.gov (United States)

    Ingersoll, C.G.; Kemble, N.E.; Kunz, J.L.; Brumbaugh, W.G.; MacDonald, D.D.; Smorong, D.

    2009-01-01

    This study was conducted to support a Natural Resource Damage Assessment and Restoration project associated with the Ashtabula River in Ohio. The objective of the study was to evaluate the chemistry and toxicity of 50 sediment samples obtained from five cores collected from the Ashtabula River (10 samples/core, with each 10-cm-diameter core collected to a total depth of about 150 cm). Effects of chemicals of potential concern (COPCs) measured in the sediment samples were evaluated by measuring whole-sediment chemistry and whole-sediment toxicity in the sediment samples (including polycyclic aromatic hydrocarbons [PAHs], polychlorinated biphenyls [PCBs], organochlorine pesticides, and metals). Effects on the amphipod Hyalella azteca at the end of a 28-day sediment toxicity test were determined by comparing survival or length of amphipods in individual sediment samples in the cores to the range of responses of amphipods exposed to selected reference sediments that were also collected from the cores. Mean survival or length of amphipods was below the lower limit of the reference envelope in 56% of the sediment samples. Concentrations of total PCBs alone in some samples or concentrations of total PAHs alone in other samples were likely high enough to have caused the reduced survival or length of amphipods (i.e., concentrations of PAHs or PCBs exceeded mechanistically based and empirically based sediment quality guidelines). While elevated concentrations of ammonia in pore water may have contributed to the reduced length of amphipods, it is unlikely that the reduced length was caused solely by elevated ammonia (i.e., concentrations of ammonia were not significantly correlated with the concentrations of PCBs or PAHs and concentrations of ammonia were elevated both in the reference sediments and in the test sediments). Results of this study show that PAHs, PCBs, and ammonia are the primary COPCs that are likely causing or substantially contributing to the toxicity to

  5. Responses of Hyalella azteca and phytoplankton to a simulated agricultural runoff event in a managed backwater wetland.

    Science.gov (United States)

    Lizotte, Richard E; Shields, F Douglas; Murdock, Justin N; Knight, Scott S

    2012-05-01

    We assessed the aqueous toxicity mitigation capacity of a hydrologically managed floodplain wetland following a synthetic runoff event amended with a mixture of sediments, nutrients (nitrogen and phosphorus), and pesticides (atrazine, S-metolachlor, and permethrin) using 48-h Hyalella azteca survival and phytoplankton pigment, chlorophyll a. The runoff event simulated a 1h, 1.27 cm rainfall event from a 16 ha agricultural field. Water (1L) was collected every 30 min within the first 4h, every 4h until 48 h, and on days 5, 7, 14, 21, and 28 post-amendment at distances of 0, 10, 40, 300 and 500 m from the amendment point for chlorophyll a, suspended sediment, nutrient, and pesticide analyses. H. azteca 48-h laboratory survival was assessed in water collected at each site at 0, 4, 24, 48 h, 5 d and 7 d. Greatest sediment, nutrient, and pesticide concentrations occurred within 3h of amendment at 0m, 10 m, 40 m, and 300 m downstream. Sediments and nutrients showed little variation at 500 m whereas pesticides peaked within 48 h but at azteca survival significantly decreased within 48 h of amendment up to 300 m in association with permethrin concentrations. Chlorophyll a decreased within the first 24h of amendment up to 40m primarily in conjunction with herbicide concentrations. Variations in chlorophyll a at 300 and 500 m were associated with nutrients. Managed floodplain wetlands can rapidly and effectively trap and process agricultural runoff during moderate rainfall events, mitigating impacts to aquatic invertebrates and algae in receiving aquatic systems.

  6. Inter-laboratory validation of organism recovery for use in 42 day sediment toxicity tests with Hyalella azteca.

    Science.gov (United States)

    Taylor, Lisa N; Novak, Lesley

    2016-10-03

    Environment and Climate Change Canada (ECCC) has developed a 42 day sediment toxicity test that includes a reproduction endpoint with the freshwater amphipod Hyalella azteca. The new methodology conducts the entire exposure in sediment; in contrast to existing standardized methods where adults are transferred to a water-only exposure before release of their first brood at Day 28. This mid-test transfer to clean water was due to the results of a juvenile H. azteca recovery trial conducted in the 1990s which concluded that reproductive endpoints could be biased because of low recovery of young amphipods from sediment. Using a new procedure and reduced volume of sediment, an inter-laboratory recovery trial was conducted using 2 to 5 day old H. azteca added to control sediment. A total of 29 technicians from eight laboratories participated in the present study. The average recovery for all laboratories and all technicians was 76% (Coefficient of Variation (CV) = 30%). Based on an initial target recovery of at least 80%, 19 out of 29 (66%) of technicians met this criterion, with an average recovery for this group of 88% (CV = 8.3%). Factors that reduced recovery success included: not using a light table, technicians with minimal sediment testing experience and the use of imported young amphipods with limited acclimation. Excluding those results, the overall average recovery which included 17 participating technicians, increased from 76 to 88% and lowered the CV from 30 to 8.6%. Based on these results, ECCC will recommend ≥85% average recovery of young in control sediment and require ≥80% as a technician performance criterion in its new test design for the reproduction methodology. This article is protected by copyright. All rights reserved.

  7. Evaluation of ability of reference toxicity tests to identify stress in laboratory populations of the amphipod Hyalella azteca

    Energy Technology Data Exchange (ETDEWEB)

    McNulty, E.W.; Ellersieck, M.R.; Rabeni, C.F. [Univ. of Missouri, Columbia, MO (United States); Dwyer, F.J.; Greer, E.I.; Ingersoll, C.G. [Geological Survey, Columbia, MO (United States). Columbia Environmental Research Center

    1999-03-01

    Standard methods for conducting toxicity tests imply that the condition of test organisms can be established using reference toxicity tests. However, only a limited number of studies have evaluated whether reference toxicity tests can actually be used to determine if organisms are in good condition, at the start of a test. The authors evaluated the ability of reference toxicants to identify stress associated with starvation in laboratory populations of the amphipod Hyalella azteca using acute toxicity tests and four reference toxicants: KCl, CdCl{sub 2}, sodium pentachlorophenate (NaPCP), and carbaryl. Stress associated with severe starvation was observed with exposure of amphipods to carbaryl or NaPCP but not with exposure to KCl or CdCl{sub 2} (i.e., lower LC50 with severe starvation). Although the LC50s for NaPCP and carbaryl were statistically different between starved and fed amphipods, this difference may not be biologically significant given the variability expected in acute lethality tests. Stress associated with sieving, heat shock, or cold shock of amphipods before the start of a test was not evident with exposure to carbaryl or KCl as reference toxicants. The chemicals evaluated in this study provided minimal information about the condition of the organisms used to start a toxicity test. Laboratories should periodically perform reference toxicity tests to assess the sensitivity of life stages or strains of test organisms. However, use of other test acceptability criteria required in standard methods, such as minimum survival, growth, or reproduction of organisms in the control treatment at the end of a test, provides more useful information about the condition of organisms used to start a test compared to data generated from reference toxicity tests.

  8. USE OF CARBOXYLESTERASE ACTIVITY TO REMOVE PYRETHROID-ASSOCIATED TOXICITY TO CERIODAPHNIA DUBIA AND HYALELLA AZTECA IN TOXICITY IDENTIFICATION EVALUATIONS

    Science.gov (United States)

    Wheelock, Craig E.; Miller, Jeff L.; Miller, Mike J.; Phillips, Bryn M.; Huntley, Sarah A.; Gee, Shirley J.; Tjeerdema, Ronald S.; Hammock, Bruce D.

    2006-01-01

    Increases in the use and application of pyrethroid insecticides have resulted in concern regarding potential effects on aquatic ecosystems. Methods for the detection of pyrethroids in receiving waters are required to monitor environmental levels of these insecticides. One method employed for the identification of causes of toxicity in aquatic samples is the toxicity identification evaluation (TIE); however, current TIE protocols do not include specific methods for pyrethroid detection. Recent work identified carboxylesterase treatment as a useful method for removing/detecting pyrethroid-associated toxicity. The present study has extended this earlier work and examined the ability of carboxylesterase activity to remove permethrin- and bifenthrin-associated toxicity to Ceriodaphnia dubia and Hyalella azteca in a variety of matrices, including laboratory water, Sacramento River (CA, USA) water, and Salinas River (CA, USA) interstitial water. Esterase activity successfully removed 1,000 ng/L of permethrin-associated toxicity and 600 ng/L of bifenthrin-associated toxicity to C. dubia in Sacramento River water. In interstitial water, 200 ng/L of permethrin-associated toxicity and 60 ng/L of bifenthrin-associated toxicity to H. azteca were removed. The selectivity of the method was validated using heat-inactivated enzyme and bovine serum albumin, demonstrating that catalytically active esterase is required. Further studies showed that the enzyme is not significantly inhibited by metals. Matrix effects on esterase activity were examined with municipal effluent and seawater in addition to the matrices discussed above. Results confirmed that the esterase retains catalytic function in a diverse array of matrices, suggesting that this technique can be adapted to a variety of aquatic samples. These data demonstrate the utility of carboxylesterase treatment as a viable step to detect the presence of pyrethroids in receiving waters. PMID:16629136

  9. Sediment Zn-release during post-drought re-flooding: Assessing environmental risk to Hyalella azteca and Daphnia magna.

    Science.gov (United States)

    Nedrich, Sara M; Burton, G Allen

    2017-11-01

    Hydrologic variability exacerbated by climate change affects biogeochemical cycling in sediments through changes in pH, redox, and microbial activity. These alterations affect the lability and speciation of metals, such that toxicity may be observed in otherwise non-toxic sediments. In this study, we investigate the effects of drought and reflooding on metal bioavailability in sediments with low to moderate concentrations of Zn (18-270 mg kg(-1)). Sediments were collected from coastal wetlands in Michigan, dried (36-days) and re-inundated in lab microcosms. We investigated the relationships between key parameters, for surface/porewater (dissolved and particulate metals, dissolved oxygen, redox (Eh), reduced iron, and temperature) and sediment (simultaneously extracted metals (SEM), acid volatile sulfide (AVS), Fe/Mn-oxyhydroxide, organic carbon, water content analyses, and diffusive gradient in thin films (DGTs) metal concentrations). Porewater Zn increased with inundation of dried sediments for all sediment types, exceeding United States Environmental Protection Agency (U.S. EPA) chronic criteria for freshwater organisms, and decreased as sediments became reduced. Effects on Hyalella azteca (7-day exposure) and Daphnia magna (10-day exposure) were quantified. Results show decreased growth of H. azteca for sites with elevated Zn and increased Zn-body concentration (BCZn) in the most contaminated sediment type. Further, BCZn was negatively correlated with H. azteca growth. D. magna survival, growth, and reproduction were not affected. DGT metal concentrations were more reflective of porewater than organism bioaccumulation. Outcomes of predictive toxicology methods are compared to toxicity test results and suggestions are provided for model improvements. This study demonstrates that post-drought re-flooding of sediments affects Zn biogeochemical cycling with potentially adverse effects on benthic organisms, even in sediments with only moderately elevated

  10. A two-step experimental design for a sediment bioassay using growth of the amphipod Hyalella azteca for the test end point

    Science.gov (United States)

    Kubitz, Jody A.; Besser, John M.; Giesy, John P.

    1996-01-01

    We designed a sediment bioassay using 25% growth inhibition of Hyalella azteca as the end point.Hyalella azteca exhibits size-specific fecundity, so growth is a surrogate of reproductive production. We investigated density effects on growth to address whether crowding could affect test interpretation; amphipods in 14,000/m2 exposures were 16 to 20% smaller than those at 7,000/m2. Using power analysis, we found that 20 to 25 samples are required to determine significance when α = 0.10 and 1 − β = 0.90. To minimize the need for laboratory resources, we designed a two-step (screening and confirmatory) bioassay, which we tested with field-collected sediments. The screening bioassay compared 11 sediments to a reference. Three sediments were “toxic” (significant growth inhibition when 1 − β = 0.66 and n = 5), five sediments were “nontoxic” (>90% of reference), and three sediments were “possibly toxic” (growth inhibition was insignificant). In the confirmatory bioassay, three possibly toxic and two nontoxic samples were reevaluated. Two were toxic (1 − β = 0.91 and n = 20), and the remaining four samples were nontoxic. In summary, five sediments were toxic and six sediments were nontoxic. The two-step analysis used minimal laboratory resources but maximized statistical power, where needed, to discriminate growth effects.

  11. Selection of food combinations to optimize survival, growth, and reproduction of the amphipod Hyalella azteca in static-renewal, water-only laboratory exposures.

    Science.gov (United States)

    Soucek, David J; Dickinson, Amy; Major, Kaley M

    2016-10-01

    Although standardized sediment toxicity testing methods have been developed for the amphipod Hyalella azteca, no standardized chronic water-only toxicity testing methods have been established. Furthermore, optimal feeding and water quality conditions for culturing and toxicity testing with this species remained unclear. The objective of the present study was to determine the food or combination of foods that best promotes survival, growth, and reproduction of the US Lab strain of Hyalella azteca under 42-d, water-only, static-renewal testing conditions. The authors conducted 7 42-d control (no toxicant) tests with various combinations of food (including Tetramin, yeast-cereal leaves-trout chow, diatoms, wheatgrass, alfalfa, and maple leaves) and substrate types (clean "unconditioned" Nitex screens vs "conditioned" Nitex screens that were colonized by live biofilms). Over all treatments, survival ranged from 18% to 96%, dry weight per individual from 0.084 mg to 1.101 mg, and reproduction from 0 young/female to 28.4 young/female. Treatments that included Tetramin tended to result in better performance than those that did not. In particular, treatments that included Tetramin and either conditioned screens or diatoms consistently had high survival, weight, and reproduction values as well as low variability among replicates (measured as coefficient of variation). A ramped Tetramin plus diatom suspension feeding regime appears to have the greatest potential to produce consistently good performance across laboratories using static-renewal systems. Environ Toxicol Chem 2016;35:2407-2415. © 2016 SETAC.

  12. Removal of garlic-like off-odours from crustacea by gamma irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Freeman, D.J.; Izzard, M.E. (Australian Atomic Energy Commission Research Establishment, Lucas Heights); Whitfield, F.B. (Commonwealth Scientific and Industrial Research Organization, North Ryde (Australia). Div. of Food Research)

    1985-04-01

    The strong garlic-like off-odours associated with the male shovel-nosed lobster (Ibacus peronii) and the royal red prawn (Hymenopenaeus sibogae) have been attributed principally to the presence of the sulphur-containing compound bis-(methylthio)-methane. In the male shovel-nosed lobster the concentration of this compound increases very rapidly following death, and a small number of contaminated crustacea may cause an entire consignment to be condemned. A method for removing this noxious odour was developed which involved gamma-irradiation of the affected crustacea using a cobalt-60 source. Eight lobsters were subjected to gamma-irradiation at a dose rate of 10 kGy an hour; one half of each was given a dose of 25 kGy and the other half a dose of 5 kGy. Results showed that a high dose completely removes the existing off-odour, and also prevents its further formation. With the lower dose the off-odour is not completely removed. A trial using fresh royal red prawns at doses of 0.5 and 1.0 kGy showed irradiation removed all traces of the off-odour, but in those irradiated at the higher dose a slight burnt flavour was noticeable.

  13. Cadmium bioavailability to Hyalella azteca from a periphyton diet compared to an artificial diet and application of a biokinetic model

    Energy Technology Data Exchange (ETDEWEB)

    Golding, Lisa A., E-mail: lisa.golding@csiro.au [Department of Biology, University of Waterloo, Waterloo, Ontario N2L 3G1 (Canada); Borgmann, Uwe [Environment Canada, 867 Lakeshore Road, Burlington, Ontario L7R 4A6 (Canada); George Dixon, D. [Department of Biology, University of Waterloo, Waterloo, Ontario N2L 3G1 (Canada)

    2013-01-15

    Differences between the bioavailability of cadmium in a periphyton diet and an artificial laboratory diet (TetraMin{sup Registered-Sign }) have important consequences for predicting bioaccumulation and toxicity in the freshwater amphipod Hyalella azteca. The assimilation efficiency (AE) of Cd was compared between periphyton and TetraMin{sup Registered-Sign} at low (1510 and 358 nmol/g ash-free dry mass respectively) and chronically lethal (31,200 and 2890 nmol/g ash-free dry mass respectively) Cd concentrations and in fresh and dry forms using a {sup 109}Cd radiotracer pulse-chase feeding technique. Assimilation efficiency of Cd from periphyton (AE = 3-14%) was lower than that for TetraMin{sup Registered-Sign} (AE = 44-86%) regardless of Cd concentration or food form. Ingestion rate (IR) was lower for dry than fresh forms of periphyton (0.042 and 0.16 g AFDM/g H. azteca/day respectively) and TetraMin{sup Registered-Sign} (0.19 and 0.87 AFDM/g H. azteca/day respectively) and depuration rate (k{sub e}) did not differ statistically with food type, form or Cd concentration (0.032-0.094 d{sup -1}). Biokinetic models with parameters of AE, IR and k{sub e} were used to estimate bioaccumulation from the separate food types. These estimates were compared to those from an independent chronic Cd saturation bioaccumulation model. While the model estimates did not concur, a sensitivity analysis indicated that AE and IR were the most influential biokinetic model parameters for Cd in periphyton and TetraMin{sup Registered-Sign} respectively. It was hypothesized that AE was underestimated for Cd in periphyton due to a non-adapted gut enzyme system and IR was overestimated for Cd in TetraMin{sup Registered-Sign} due to an initial rapid ingestion phase in H. azteca's feeding habits. This research demonstrated the importance of using ecologically relevant food types in laboratory experiments and verifying acute biokinetic model predictions of dietary metal contribution with

  14. Oxidized Carbo-Iron causes reduced reproduction and lower tolerance of juveniles in the amphipod Hyalella azteca.

    Science.gov (United States)

    Weil, Mirco; Meißner, Tobias; Springer, Armin; Bundschuh, Mirco; Hübler, Lydia; Schulz, Ralf; Duis, Karen

    2016-12-01

    For in situ remediation of groundwater contaminated by halogenated hydrocarbons Carbo-Iron(®), a composite of microscale activated carbon and nano Fe(0), was developed. Against the background of intended release of Carbo-Iron into the environment in concentrations in the g/L-range, potential ecotoxicological consequences were evaluated in the present study. The nano Fei(0) in Carbo-Iron acts as reducing agent and is oxidized in aqueous systems by chlorinated solvents, groundwater constituents (e.g. dissolved oxygen) and anaerobic corrosion. As Carbo-Iron is generally oxidized rapidly after application into the environment, the oxidized state is environmentally most relevant, and Carbo-Iron was used in its oxidized form in the ecotoxicological tests. The amphipod Hyalella azteca was selected as a surrogate test species for functionally important groundwater crustaceans. Effects of Carbo-Iron on H. azteca were determined in a 10-d acute test, a 7-d feeding activity test and a 42-d chronic test. Additionally, a 56-d life cycle test was performed with a modified design to further evaluate effects of Carbo-Iron on adult H. azteca and their offspring. The size of Carbo-Iron particles in stock and test suspensions was determined via dynamic light scattering. Potential uptake of particles into test organisms was investigated using transmission and scanning electron microscopy. At the termination of the feeding and acute toxicity test (i.e. after 7 and 10 d of exposure, respectively), Carbo-Iron had a significant effect on the weight, length and feeding rate of H. azteca at the highest test concentration of 100mg/L. While an uptake of Carbo-Iron into the gut was observed, no passage into the surrounding tissue was detected. In both chronic tests, the number of offspring was the most sensitive endpoint and significant effects were recorded at concentrations ≥50mg/L (42-d experiment) and ≥12.5mg/L (56-d experiment). Parental exposure to oxidized Carbo-Iron significantly

  15. Predicting toxicity to Hyalella azteca in pyrogenic-impacted sediments-Do we need to analyze for all 34 PAHs?

    Science.gov (United States)

    Geiger, Stephen C; Azzolina, Nicholas A; Nakles, David V; Hawthorne, Steven B

    2016-07-01

    Polycyclic aromatic hydrocarbons (PAHs) are major drivers of risk at many urban and/or industrialized sediment sites. The US Environmental Protection Agency (USEPA) currently recommends using measurements of 18 parent + 16 groups of alkylated PAHs (PAH-34) to assess the potential for sediment-bound PAHs to impact benthic organisms at these sites. ASTM Method D7363-13 was developed to directly measure low-level sediment porewater PAH concentrations. These concentrations are then compared to ambient water criteria (final chronic values [FCVs]) to assess the potential for impact to benthic organisms. The interlaboratory validation study that was used to finalize ASTM D7363-13 was developed using 24 of the 2-, 3-, and 4-ring PAHs (PAH-24) that are included in the USEPA PAH-34 analyte list. However, it is the responsibility of the user of ASTM Method D7363 to establish a test method to quantify the remaining 10 higher molecular weight PAHs that make up PAH-34. These higher molecular weight PAHs exhibit extremely low saturation solubilities that make their detection difficult in porewater, which has proven difficult to implement in a contract laboratory setting. As a result, commercial laboratories are hesitant to conduct the method on the entire PAH-34 analyte list. This article presents a statistical comparison of the ability of the PAH-24 and PAH-34 porewater results to predict survival of the freshwater amphipod Hyalella azteca, using the original 269 sediment samples used to gain ASTM D7363 Method approval. The statistical analysis shows that the PAH-24 are statistically indistinguishable from the PAH-34 for predicting toxicity. These results indicate that the analysis of freely dissolved porewater PAH-24 is sufficient for making risk-based decisions based on benthic invertebrate toxicity (survival and growth). This reduced target analyte list should result in a cost-saving for stakeholders and broader implementation of the method at PAH-impacted sediment sites

  16. Cadmium bioavailability to Hyalella azteca from a periphyton diet compared to an artificial diet and application of a biokinetic model.

    Science.gov (United States)

    Golding, Lisa A; Borgmann, Uwe; George Dixon, D

    2013-01-15

    Differences between the bioavailability of cadmium in a periphyton diet and an artificial laboratory diet (TetraMin(®)) have important consequences for predicting bioaccumulation and toxicity in the freshwater amphipod Hyalella azteca. The assimilation efficiency (AE) of Cd was compared between periphyton and TetraMin(®) at low (1510 and 358 nmol/g ash-free dry mass respectively) and chronically lethal (31,200 and 2890 nmol/g ash-free dry mass respectively) Cd concentrations and in fresh and dry forms using a (109)Cd radiotracer pulse-chase feeding technique. Assimilation efficiency of Cd from periphyton (AE=3-14%) was lower than that for TetraMin(®) (AE=44-86%) regardless of Cd concentration or food form. Ingestion rate (IR) was lower for dry than fresh forms of periphyton (0.042 and 0.16 g AFDM/g H. azteca/day respectively) and TetraMin(®) (0.19 and 0.87 AFDM/g H. azteca/day respectively) and depuration rate (k(e)) did not differ statistically with food type, form or Cd concentration (0.032-0.094 d(-1)). Biokinetic models with parameters of AE, IR and k(e) were used to estimate bioaccumulation from the separate food types. These estimates were compared to those from an independent chronic Cd saturation bioaccumulation model. While the model estimates did not concur, a sensitivity analysis indicated that AE and IR were the most influential biokinetic model parameters for Cd in periphyton and TetraMin(®) respectively. It was hypothesized that AE was underestimated for Cd in periphyton due to a non-adapted gut enzyme system and IR was overestimated for Cd in TetraMin(®) due to an initial rapid ingestion phase in H. azteca's feeding habits. This research demonstrated the importance of using ecologically relevant food types in laboratory experiments and verifying acute biokinetic model predictions of dietary metal contribution with those derived from a chronic exposure which is more representative of a field exposure scenario.

  17. A cladistic analysis of the genera of Macrothricidae Norman & Brady (Crustacea, Cladocera, Radopoda Análise cladística dos gêneros de Macrothticidae Norman & Brady (Crustacea, Cladocera, Radopoda

    Directory of Open Access Journals (Sweden)

    Lourdes M. A. Elmoor-Loureiro

    2005-09-01

    Full Text Available A cladistic analysis of the genera of the Macrothricidae (Crustacea, Cladocera, Radopoda was performed based on 36 morphological characters, and including 15 terminal taxa (three as outgroups. The single tree obtained from this analysis supported the monophyly of Macrothricidae and Macrothricinae. The group called as "non-Macrothricinae" was indicated as paraphyletic. Neothricidae was also not supported.Foi conduzida uma análise cladística dos gêneros sul-americanos de Macrothricidae (Crustacea, Cladocera, Radopoda com base em 36 caracteres morfológicos e incluindo 15 taxa terminais (três como grupos externos. Uma única árvore foi obtida pela análise, a qual suporta o monofiletismo de Macrothricidae e de Macrothricinae. O grupo chamado de "não-Macrothricinae" é indicado como parafilético. Neothricidae também não encontrou suporte.

  18. First record of Puerulus mesodontus Chan, Ma & Chu, 2013 (Crustacea, Decapoda, Achelata, Palinuridae) from south of Java, Indonesia.

    Science.gov (United States)

    Wardiatno, Yusli; Hakim, Agus Alim; Mashar, Ali; Butet, Nurlisa Alias; Adrianto, Luky; Farajallah, Achmad

    2016-01-01

    Three specimens of Puerulus mesodontus Chan, Ma & Chu, 2013 (Crustacea, Decapoda, Achelata, Palinuridae) were collected from Palabuhanratu Bay, southern Java, Indonesia. There is no previous record on the presence of the species in Indonesia. This finding represents the first record of this species in Java, Indonesia, and confirms that the species is present in the Indian Ocean. The morphological characters of the species are described. This paper contains a new distribution record of a lobster species from Indonesian waters.

  19. Population structure and reproductive biology of Mesopodopsis orientalis (Crustacea: Mysida) in a tropical mangrove ecosystem in India

    Digital Repository Service at National Institute of Oceanography (India)

    Biju, A.; Panampunnayil, S.U.

    , Sawamoto (1985) obtained an opposite result for the same species in neighboring water of Japan. Delgado et al. (1997) mentioned that clutch size of Mesopodopsis slabberi (van Beneden) vary depending on the geographic populations or different...) Fisheries of planktonic shrimp and shrimp-like in the Gulf of Thailand. Thai Fish Gazet 35, 67 – 88. Delgado L., Guerao G. and Ribera C. (1997) Biology of the mysid Mesopodopsis slabberi (van Beneden, 1861) (Crustacea, Mysidacea) in the coastal lagoon...

  20. Use of GC × GC/TOF-MS and LC/TOF-MS for metabolomic analysis of Hyalella azteca chronically exposed to atrazine and its primary metabolite, desethylatrazine.

    Science.gov (United States)

    Ralston-Hooper, Kimberly J; Adamec, Jiri; Jannash, Amber; Mollenhauer, Robert; Ochoa-Acuña, Hugo; Sepúlveda, Maria S

    2011-07-01

    Atrazine is one of the most commonly detected contaminants in the U.S. Little information is available on one of atrazine's metabolites, desethylatrazine (DEA). Two-dimensional gas chromatography and liquid chromatography coupled with time of flight- mass spectrometry were used to examine metabolite profiles of Hyalella azteca chronically exposed to 30 µg/L atrazine and DEA. The majority of identified metabolites were by-products of β-oxidation of fatty acids suggesting possible disruption in energy metabolism. Eicosanoids increased in exposed females suggesting possible perturbations in neuropeptide hormonal systems. Overall, this research demonstrates the feasibility of utilizing metabolomic profiling of invertebrate species exposed to environmental contaminants as a way to determine mechanisms of toxicity.

  1. Survival, growth, and body residues of hyalella azteca (Saussure) exposed to fipronil contaminated sediments from non-vegetated and vegetated microcosms.

    Science.gov (United States)

    Kröger, Robert; Lizotte, Richard E; Moore, Matthew T

    2009-09-01

    We assessed chronic effects of fipronil and metabolite contaminated sediments from non-vegetated and Thallia dealbata vegetated wetland microcosms on Hyalella azteca during wet and dry exposures. Mean sediment concentrations (ng g(-1)) ranged from 0.72-1.26, 0.01-0.69, 0.07-0.23, and 0.49-7.87 for fipronil, fipronil-sulfide, fipronil-sulfone, and fipronil-desulfinyl, respectively. No significant differences in animal survival or growth were observed between non-vegetated and vegetated microcosms during wet or dry exposures. Mean animal body residue concentrations (ng g(-1)) ranged from 28.4-77.6, 0-30.7, and 8.3-43.8 for fipronil, fipronil-sulfide, and fipronil-sulfone. Fipronil-desulfinyl was not detected in any animal samples.

  2. Chronic TiO{sub 2} nanoparticle exposure to a benthic organism, Hyalella azteca: impact of solar UV radiation and material surface coatings on toxicity

    Energy Technology Data Exchange (ETDEWEB)

    Wallis, Lindsay K. [Office of Research and Development, Mid-Continent Ecology Division, National Health and Environmental Effects Research Laboratory, U.S. Environmental Protection Agency, Duluth, MN, 55804 (United States); Diamond, Stephen A. [Nanosafe Inc., Blacksburg, VA, 24060 (United States); Ma, Hongbo [University of Wisconsin-Milwaukee, Zilber School of Public Health, Milwaukee, WI, 53211 (United States); Hoff, Dale J. [Office of Research and Development, Mid-Continent Ecology Division, National Health and Environmental Effects Research Laboratory, U.S. Environmental Protection Agency, Duluth, MN, 55804 (United States); Al-Abed, Souhail R. [National Risk Management Research Laboratory, U.S. Environmental Protection Agency, Cincinnati, OH 45268 (United States); Li, Shibin, E-mail: lishibinepa@gmail.com [Office of Research and Development, Mid-Continent Ecology Division, National Health and Environmental Effects Research Laboratory, U.S. Environmental Protection Agency, Duluth, MN, 55804 (United States)

    2014-11-15

    There is limited information on the chronic effects of nanomaterials to benthic organisms, as well as environmental mitigating factors that might influence this toxicity. The present study aimed to fill these data gaps by examining various growth endpoints (weight gain, instantaneous growth rate, and total protein content) for up to a 21 d sediment exposure of TiO{sub 2} nanoparticles (nano-TiO{sub 2}) to a representative benthic species, Hyalella azteca. An uncoated standard, P25, and an Al(OH){sub 3} coated nano-TiO{sub 2} used in commercial products were added to sediment at 20 mg/L or 100 mg/L Under test conditions, UV exposure alone was shown to be a greater cause of toxicity than even these high levels of nano-TiO{sub 2} exposure, indicating that different hazards need to be addressed in toxicity testing scenarios. In addition, this study showed the effectiveness of a surface coating on the decreased photoactivity of the material, as the addition of an Al(OH){sub 3} coating showed a dramatic decrease in reactive oxygen species (ROS) production. However, this reduced photoactivity was found to be partially restored when the coating had been degraded, leading to the need for future toxicity tests which examine the implications of weathering events on particle surface coatings. - Highlights: • Chronic toxicity of nano-TiO{sub 2} to a benthic organism (Hyalella azteca) was examined. • Phototoxicity was investigated through exposure of solar simulated radiation (SSR). • The degradation of a surface coating resulted in an increase in photoactivity. • In this testing scenario, UV had a larger impact than chemical exposure in toxicity.

  3. Environmental fate of pyrethroids in urban and suburban stream sediments and the appropriateness of Hyalella azteca model in determining ecological risk.

    Science.gov (United States)

    Palmquist, Katherine; Fairbrother, Anne; Salatas, Johanna; Guiney, Patrick D

    2011-07-01

    According to several recent studies using standard acute Hyalella azteca sediment bioassays, increased pyrethroid use in urban and suburban regions in California has resulted in the accumulation of toxic concentrations of pyrethroids in sediments of area streams and estuaries. However, a critical review of the literature indicates that this is likely an overestimation of environmental risk. Hyalella azteca is consistently the most susceptible organism to both aqueous and sediment-associated pyrethroid exposures when compared to a suite of other aquatic taxa. In some cases, H. azteca LC50 values are less than the community HC10 values, suggesting that the amphipod is an overly conservative model for community- or ecosystem-level impacts of sediment-associated pyrethroids. Further, as a model for responses of field populations of H. azteca, the laboratory bioassays considerably overestimate exposure, because the amphipod is more appropriately characterized as an epibenthic organism, not a true sediment dweller; H. azteca preferentially inhabit aquatic macrophytes, periphyton mats, and leaf litter, which drastically reduces their exposure to contaminated sediments. Sediment-bound pyrethroids are transported via downstream washing of fine particulates resulting in longer range transport but also more efficient sequestration of the chemical. In addition, site-specific variables such as sediment organic carbon content, grain size, temperature, and microbial activity alter pyrethroid bioavailability, degradation, and toxicity on a microhabitat scale. The type and source of the carbon in particular, influences the pyrethroid sequestering ability of sediments. The resulting irregular distribution of pyrethroids in stream sediments suggests that sufficient nonimpacted habitat may exist as refugia for resident sediment-dwelling organisms for rapid recolonization to occur. Given these factors, we argue that the amphipod model provides, at best, a screening level assessment of

  4. Male meiosis in Crustacea: synapsis, recombination, epigenetics and fertility in Daphnia magna.

    Science.gov (United States)

    Gómez, Rocío; Van Damme, Kay; Gosálvez, Jaime; Morán, Eugenio Sánchez; Colbourne, John K

    2016-09-01

    We present the first detailed cytological study of male meiosis in Daphnia (Crustacea: Branchiopoda: Cladocera)-an aquatic microcrustacean with a cyclical parthenogenetic life cycle. Using immunostaining of the testes in Daphnia magna for baseline knowledge, we characterized the different stages of meiotic division and spermiogenesis in relation to the distribution of proteins involved in synapsis, early recombination events and sister chromatid cohesion. We also studied post-translational histone modifications in male spermatocytes, in relation to the dynamic chromatin progression of meiosis. Finally, we applied a DNA fragmentation test to measure sperm quality of D. magna, with respect to levels of inbreeding. As a proxy for fertility, this technique may be used to assess the reproductive health of a sentinel species of aquatic ecosystems. Daphnia proves to be a model species for comparative studies of meiosis that is poised to improve our understanding of the cytological basis of sexual and asexual reproduction.

  5. Reference values for feeding parameters of isopods (Porcellio scaber, Isopoda, Crustacea)

    Science.gov (United States)

    Drobne, Damjana; Drobne, Samo

    2014-01-01

    Abstract The advantage of using terrestrial isopods in toxicity studies is that a battery of parameters can be tested at different levels of biological complexity. Feeding parameters for example link organism level response to potential ecological consequences but a problem with using feeding parameters in toxicity tests with terrestrial isopods is their high variability. The aim of our study was to set benchmark values for feeding parameters for isopod Porcellio scaber (Isopoda, Crustacea) in laboratory-controlled experiments. In the work presented here, the daily feeding rate of the central 50% of the control population of Porcellio scaber and a correlation between feeding rate and isopod weight were set. Values outside these ranges need additional evaluation to increase the relevance of test outcomes. We suggest using benchmark values for feeding parameters as well as the coefficient of variation (a) to identify animals with altered feeding parameters with respect to controls, and (b) to assess the data quality in each experiment. PMID:25561844

  6. Reference values for feeding parameters of isopods (Porcellio scaber, Isopoda, Crustacea

    Directory of Open Access Journals (Sweden)

    Damjana Drobne

    2014-11-01

    Full Text Available The advantage of using terrestrial isopods in toxicity studies is that a battery of parameters can be tested at different levels of biological complexity. Feeding parameters for example link organism level response to potential ecological consequences but a problem with using feeding parameters in toxicity tests with terrestrial isopods is their high variability. The aim of our study was to set benchmark values for feeding parameters for isopod Porcellio scaber (Isopoda, Crustacea in laboratory-controlled experiments. In the work presented here, the daily feeding rate of the central 50% of the control population of P. scaber and a correlation between feeding rate and isopod weight were set. Values outside these ranges need additional evaluation to increase the relevance of test outcomes. We suggest using benchmark values for feeding parameters as well as the coefficient of variation (a to identify animals with altered feeding parameters with respect to controls, and (b to assess the data quality in each experiment.

  7. Phagocytosis mediates specificity in the immune defence of an invertebrate, the woodlouse Porcellio scaber (Crustacea: Isopoda).

    Science.gov (United States)

    Roth, Olivia; Kurtz, Joachim

    2009-11-01

    Specificity and memory are the hallmarks of the adaptive immune system of vertebrates. However, phenomena of specificity upon priming of immunity have recently been demonstrated also in invertebrates, which rely exclusively on innate immune defence. It has been suggested that phagocytosis might represent a core candidate for such specificity in invertebrates. We here developed in vitro phagocytosis measurements for different bacteria in the woodlouse Porcellio scaber (Crustacea: Isopoda). After immune priming with heat-killed bacteria, hemocytes showed increased phagocytosis of a previously encountered bacterial strain compared to other bacteria. These data support the role of phagocytosis in invertebrate immunological specificity and suggest a high degree of specificity that even enables to differentiate between strains of the same bacterial species.

  8. Occurence of the Asian shrimp Palaemon macrodactylus in the Southern bight of the North Sea, with a key to the Palaemonidae of North-western Europe (Crustacea: Decapoda: Caridea)

    NARCIS (Netherlands)

    d'Udekem d'Azoc, C.; Faasse, M.; Dumoulin, E.; Blauwe, de H.

    2005-01-01

    Het voorkomen van de rugstreepsteurgarnaal Palaemon macrodactylus in de zuidelijke bocht van de Noordzee, met een determinatiesleutel tot de Palaemonidae van Noordwest-Europa (Crustacea: Decapoda: Caridea) In 1999 werd de rugstreepsteurgarnaal Palaemon macrodactylus Rathbun, 1902, een soort

  9. 酸损害湖泊中底栖无脊椎动物(Stenacron interpunctatum,Stenonema femoratum和Hyalella azteca)的再集群现象%Recolonization of Acid-damaged Lakes by the Benthic Invertebrates Stenacron interpunctatum, Stenonema femoratum and Hyalella azteca

    Institute of Scientific and Technical Information of China (English)

    Ed Snucins

    2003-01-01

    本文描述了加拿大基拉尼公园里的酸损害湖中3种底栖无脊椎动物的再集群现象:它们是两种蜉蝣类动物(Stenonema femoratum,Stenacron interpunctatum)和一种端足类甲壳动物(Hyalella azteca)。1995-1997年间对119个湖的端足类甲壳动物以及77个湖的蜉蝣类动物进行了概要调查,同时确定Stenonema femoratum和Hyalella azteca的pH临界值是5.6。而Stenacron interpunctatum的pH临界值是5.3。从1997-2002年,通过对2个酸损害湖和2个参考湖深入研究。在能够估计出出现时间的地方,种的pH阈值达到后不到4-8年。就可以重建Stenacron interpunctatum,Stenonema femoratum和Hyalella azteca。在最小的湖(11hm2)中监测到集群现象之后3年。该湖内Stenacron interpunctatum到所有栖息地的扩散完成。可以预测,Stenacron interpunctatum在最大的湖(189hm2)内的扩散需要更长的时间。从估算的pH值恢复到湖内蜉蝣类动物重建,再到其后扩散到所有适合栖息地的时间滞后为11-22年之久或更长。虽然在恢复湖中Stenacron interpunctatum的密度增加到高于参考湖的水平。但在6年期间的监测中尚未达到稳定的终点。

  10. Behavioural alterations from exposure to Cu, phenanthrene, and Cu-phenanthrene mixtures: linking behaviour to acute toxic mechanisms in the aquatic amphipod, Hyalella azteca.

    Science.gov (United States)

    Gauthier, Patrick T; Norwood, Warren P; Prepas, Ellie E; Pyle, Greg G

    2016-01-01

    Phenanthrene (PHE) and Cu are two contaminants commonly co-occurring in marine and freshwater environments. Mixtures of PHE and Cu have been reported to induce more-than-additive lethality in the amphipod, Hyalella azteca, a keystone aquatic invertebrate, yet little is understood regarding the interactive toxic mechanisms that mediate more-than-additive toxicity. Understanding the interactions among toxic mechanisms among Cu and PHE will allow for better predictive power in assessing the ecological risks of Cu-PHE mixtures in aquatic environments. Here we use behavioural impairment to help understand the toxic mechanisms of Cu, PHE, and Cu-PHE mixture toxicity in the aquatic amphipod crustacean, Hyalella azteca. Our principal objective was to link alterations in activity and ventilation with respiratory rates, oxidative stress, and neurotoxicity in adult H. azteca. Adult amphipods were used for all toxicity tests. Amphipods were tested at sublethal exposures of 91.8- and 195-μgL(-1) Cu and PHE, respectively, and a Cu-PHE mixture at the same concentrations for 24h. Neurotoxicity was measured as acetylcholinesterase (AChE) activity, where malathion was used as a positive control. Oxidative stress was measured as reactive oxygen species (ROS) production. Phenanthrene-exposed amphipods exhibited severe behavioural impairment, being hyperstimulated to the extent that they were incapable of coordinating muscle movements. In addition, respiration and AChE activity in PHE-exposed amphipods were increased and reduced by 51% and 23% respectively. However, ROS did not increase following exposure to phenanthrene. In contrast, Cu had no effect on amphipod behaviour, respiration or AChE activity, but did lead to an increase in ROS. However, co-exposure to Cu antagonized the PHE-induced reduction in ventilation and negated any increase in respiration. The results suggest that PHE acts like an organophosphate pesticide (e.g., malathion) in H. azteca following 24h sublethal

  11. Ecologia populacional, estratégias reprodutivas e uso de recursos por isópodos terrestres neotropicais (Crustacea, isopoda)

    OpenAIRE

    Aline Ferreira Quadros

    2009-01-01

    Os isópodos terrestres (Crustacea, Oniscidea) apresentam adaptações únicas à vida terrestre, tanto fisiológicas quanto morfológicas e comportamentais. Habitam uma grande variedade de ambientes e são facilmente capturados e mantidos em laboratório, constituindo assim um ótimo modelo para investigações que contribuam para um melhor entendimento da ecologia de solo. Apesar de sua grande importância para o funcionamento dos ecossistemas através da detritivoria e da posição chave que ocupam nas te...

  12. Binary mixtures of diclofenac with paracetamol, ibuprofen, naproxen, and acetylsalicylic acid and these pharmaceuticals in isolated form induce oxidative stress on Hyalella azteca.

    Science.gov (United States)

    Gómez-Oliván, Leobardo Manuel; Neri-Cruz, Nadia; Galar-Martínez, Marcela; Islas-Flores, Hariz; García-Medina, Sandra

    2014-11-01

    Toxicity in natural ecosystems is usually not due to exposure to a single substance, but is rather the result of exposure to mixtures of toxic substances. Knowing the effects of contaminants as a mixture compared to their effects in isolated form is therefore important. This study aimed to evaluate the oxidative stress induced by binary mixtures of diclofenac with paracetamol, ibuprofen, naproxen, and acetylsalicylic acid and by these nonsteroidal anti-inflammatory drugs (NSAIDs) in isolated form, using Hyalella azteca as a bioindicator. The median lethal concentration (LC50) and the lowest observed adverse effect level (LOAEL) of each NSAID were obtained. Amphipods were exposed for 72 h to the latter value in isolated form and as binary mixtures. The following biomarkers were evaluated: lipid peroxidation (LPX), protein carbonyl content (PCC), and activity of the antioxidant enzymes: superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx). Significant increases in LPX and PCC with respect to the control group (p ≤ 0.05) were induced by NSAIDs both in isolated form and as binary mixtures. Changes in SOD, CAT, and GPx activity likewise occurred with NSAIDs in isolated form and as binary mixtures. In conclusion, NSAIDs used in this study induce oxidative stress on H. azteca both in isolated form and as binary mixtures, and the interactions occurring between these pharmaceuticals are probably antagonistic in type.

  13. Comparing the effectiveness of chronic water column tests with the crustaceans Hyalella azteca (order: Amphipoda) and Ceriodaphnia dubia (order: Cladocera) in detecting toxicity of current-use insecticides.

    Science.gov (United States)

    Deanovic, Linda A; Markiewicz, Dan; Stillway, Marie; Fong, Stephanie; Werner, Inge

    2013-03-01

    Standard U.S. Environmental Protection Agency laboratory tests are used to monitor water column toxicity in U.S. surface waters. The water flea Ceriodaphnia dubia is among the most sensitive test species for detecting insecticide toxicity in freshwater environments.Its usefulness is limited, however, when water conductivity exceeds 2,000 µS/cm (approximately 1 ppt salinity) and test effectiveness is insufficient. Water column toxicity tests using the euryhaline amphipod Hyalella azteca could complement C. dubia tests; however, standard chronic protocols do not exist. The present study compares the effectiveness of two water column toxicity tests in detecting the toxicity of two organophosphate (OP) and two pyrethroid insecticides: the short-term chronic C. dubia test, which measures mortality and fecundity, and a 10-d H. azteca test, which measures mortality and growth. Sensitivity was evaluated by comparing effect data, and end point variability was evaluated by comparing minimum significant differences. Tests were performed in synthetic water and filtered ambient water to quantify the influence of water matrix on effect concentrations. The H. azteca test detected pyrethroid toxicity far more effectively, while the C. dubia test was more sensitive to OPs. Among endpoints, H. azteca mortality was most robust. The results demonstrate that the H. azteca test is preferable when conductivity of water samples is 2,000 to 10,000 µS/cm or if contaminants of concern include pyrethroid insecticides.

  14. History and sensitivity comparison of two standard whole-sediment toxicity tests with crustaceans: the amphipod Hyalella azteca and the ostracod Heterocypris incongruens microbiotest

    Directory of Open Access Journals (Sweden)

    De Cooman W.

    2015-01-01

    Full Text Available The review first details the development of the test procedures with Hyalella azteca which historically emerged as one of the recommended test species for whole-sediment assays and its gradual standardization and endorsement by national and international organizations. The sensitivity and precision of the H. azteca test for application on chemicals and on real world sediments is discussed. The review subsequently addresses the development of the whole sediment microbiotest with the ostracod crustacean Heterocypris incongruens with larvae of this test species hatched from dormant eggs (cysts, rendering this assay stock culture/maintenance free. The application of the 6-day ostracod microbiotest on sediments in Canada and in Belgium is discussed, as well as its endorsement by the ISO subsequent to an extensive international interlaboratory ring test. The sensitivity of the amphipod and ostracod tests is compared by data from studies in which both assays were applied in parallel. A comparison of more than 1000 ostracod/amphipod data pairs of a 12-year river sediment monitoring study in Flanders/Belgium confirmed that both whole-sediment assays have a similar sensitivity and that the 6-day ostracod microbiotest is a valuable and cost-effective alternative to the 10−14 day amphipod test for evaluation of the toxic hazard of polluted sediments.

  15. An analysis of lethal and sublethal interactions among type I and type II pyrethroid pesticide mixtures using standard Hyalella azteca water column toxicity tests.

    Science.gov (United States)

    Hoffmann, Krista Callinan; Deanovic, Linda; Werner, Inge; Stillway, Marie; Fong, Stephanie; Teh, Swee

    2016-10-01

    A novel 2-tiered analytical approach was used to characterize and quantify interactions between type I and type II pyrethroids in Hyalella azteca using standardized water column toxicity tests. Bifenthrin, permethrin, cyfluthrin, and lambda-cyhalothrin were tested in all possible binary combinations across 6 experiments. All mixtures were analyzed for 4-d lethality, and 2 of the 6 mixtures (permethrin-bifenthrin and permethrin-cyfluthrin) were tested for subchronic 10-d lethality and sublethal effects on swimming motility and growth. Mixtures were initially analyzed for interactions using regression analyses, and subsequently compared with the additive models of concentration addition and independent action to further characterize mixture responses. Negative interactions (antagonistic) were significant in 2 of the 6 mixtures tested, including cyfluthrin-bifenthrin and cyfluthrin-permethrin, but only on the acute 4-d lethality endpoint. In both cases mixture responses fell between the additive models of concentration addition and independent action. All other mixtures were additive across 4-d lethality, and bifenthrin-permethrin and cyfluthrin-permethrin were also additive in terms of subchronic 10-d lethality and sublethal responses. Environ Toxicol Chem 2016;35:2542-2549. © 2016 SETAC.

  16. Monitoring acute and chronic water column toxicity in the Northern Sacramento-San Joaquin Estuary, California, USA, using the euryhaline amphipod, Hyalella azteca: 2006 to 2007.

    Science.gov (United States)

    Werner, Inge; Deanovic, Linda A; Markiewicz, Dan; Khamphanh, Manisay; Reece, Charles K; Stillway, Marie; Reece, Charissa

    2010-10-01

    After the significant population decline of several pelagic fish species in the Northern Sacramento-San Joaquin (SSJ) Estuary (CA, USA) in 2002, a study was performed to monitor water column toxicity using the amphipod Hyalella azteca. From January 1, 2006 to December 31, 2007, water samples were collected biweekly from 15 to 16 sites located in large delta channels and main-stem rivers, selected based on prevalent distribution patterns of fish species of concern. Ten-day laboratory tests with H. azteca survival and relative growth as toxicity endpoints were conducted. The enzyme inhibitor piperonyl butoxide ([PBO], 25 µg/L) was added to synergize or antagonize pyrethroid or organophosphate (OP) insecticide toxicity, respectively. Significant amphipod mortality was observed in 5.6% of ambient samples. Addition of PBO significantly changed survival or growth in 1.1% and 10.1% of ambient samples, respectively. Sites in the Lower Sacramento River had the largest number of acutely toxic samples, high occurrence of PBO effects on amphipod growth (along with sites in the South Delta), and the highest total ammonia/ammonium concentrations (0.28 ± 0.15 mg/L). Ammonia/ammonium, or contaminants occurring in mixture with these, likely contributed to the observed toxicity. Pyrethroid insecticides were detected at potentially toxic concentrations. Overall, results of this study identified specific areas and contaminants of concern and showed that water in the Northern SSJ Estuary was at times acutely toxic to sensitive invertebrates.

  17. Validation of a chronic dietary cadmium bioaccumulation and toxicity model for Hyalella azteca exposed to field-contaminated periphyton and lake water.

    Science.gov (United States)

    Golding, Lisa A; Borgmann, Uwe; Dixon, D George

    2011-11-01

    A model previously developed in the laboratory to predict chronic bioaccumulation and toxicity of cadmium to Hyalella azteca from a diet of periphyton was validated by comparing predictions with measurements of Cd in two exposure scenarios: laboratory-cultured H. azteca exposed for 28 d to field-contaminated water and periphyton, and Cd measured in field-collected H. azteca. In both exposure scenarios, model predictions of bioaccumulation were shown to be robust; however, effects on Cd bioaccumulation from complexation with dissolved organic carbon (DOC) and inhibition of Cd bioaccumulation by Ca²⁺ must be incorporated into the model to permit its wider application. The model predicted that 80 to 84% of Cd in H. azteca came from periphyton when H. azteca were chronically exposed to dissolved Cd in lake water at 2.63 to 3.01 nmol/L and periphyton at 1,880 to 2,630 nmol/g ash-free dry mass. Dietary Cd contributed markedly to the model-predicted decrease in 28-d survival to 74% at environmental Cd concentrations in food and water. In reality, survival decreased to 10%. The lower than predicted survival likely was due to the higher nutritional quality of periphyton used to develop the model in the laboratory compared with the field-collected periphyton. Overall, this research demonstrated that Cd in a periphyton diet at environmental concentrations can contribute to chronic toxicity in H. azteca.

  18. Chronic TiO₂ nanoparticle exposure to a benthic organism, Hyalella azteca: impact of solar UV radiation and material surface coatings on toxicity.

    Science.gov (United States)

    Wallis, Lindsay K; Diamond, Stephen A; Ma, Hongbo; Hoff, Dale J; Al-Abed, Souhail R; Li, Shibin

    2014-11-15

    There is limited information on the chronic effects of nanomaterials to benthic organisms, as well as environmental mitigating factors that might influence this toxicity. The present study aimed to fill these data gaps by examining various growth endpoints (weight gain, instantaneous growth rate, and total protein content) for up to a 21 d sediment exposure of TiO2 nanoparticles (nano-TiO2) to a representative benthic species, Hyalella azteca. An uncoated standard, P25, and an Al(OH)3 coated nano-TiO2 used in commercial products were added to sediment at 20 mg/L or 100 mg/L Under test conditions, UV exposure alone was shown to be a greater cause of toxicity than even these high levels of nano-TiO2 exposure, indicating that different hazards need to be addressed in toxicity testing scenarios. In addition, this study showed the effectiveness of a surface coating on the decreased photoactivity of the material, as the addition of an Al(OH)3 coating showed a dramatic decrease in reactive oxygen species (ROS) production. However, this reduced photoactivity was found to be partially restored when the coating had been degraded, leading to the need for future toxicity tests which examine the implications of weathering events on particle surface coatings.

  19. An effects addition model based on bioaccumulation of metals from exposure to mixtures of metals can predict chronic mortality in the aquatic invertebrate Hyalella azteca.

    Science.gov (United States)

    Norwood, Warren P; Borgmann, Uwe; Dixon, D George

    2013-07-01

    Chronic toxicity tests of mixtures of 9 metals and 1 metalloid (As, Cd, Co, Cr, Cu, Mn, Ni, Pb, Tl, and Zn) at equitoxic concentrations over an increasing concentration range were conducted with the epibenthic, freshwater amphipod Hyalella azteca. The authors conducted 28-d, water-only tests. The bioaccumulation trends changed for 8 of the elements in exposures to mixtures of the metals compared with individual metal exposures. The bioaccumulation of Co and Tl were affected the most. These changes may be due to interactions between all the metals as well as interactions with waterborne ligands. A metal effects addition model (MEAM) is proposed as a more accurate method to assess the impact of mixtures of metals and to predict chronic mortality. The MEAM uses background-corrected body concentration to predict toxicity. This is important because the chemical characteristics of different waters can greatly alter the bioavailability and bioaccumulation of metals, and interactions among metals for binding at the site of action within the organism can affect body concentration. The MEAM accurately predicted toxicity in exposures to mixtures of metals, and predicted results were within a factor of 1.1 of the observed data, using 24-h depurated body concentrations. The traditional concentration addition model overestimated toxicity by a factor of 2.7.

  20. Contaminants in stream sediments from seven United States metropolitan areas: part II--sediment toxicity to the amphipod Hyalella azteca and the midge Chironomus dilutus.

    Science.gov (United States)

    Kemble, Nile E; Hardesty, Douglas K; Ingersoll, Christopher G; Kunz, James L; Sibley, Paul K; Calhoun, Daniel L; Gilliom, Robert J; Kuivila, Kathryn M; Nowell, Lisa H; Moran, Patrick W

    2013-01-01

    Relationships between sediment toxicity and sediment chemistry were evaluated for 98 samples collected from seven metropolitan study areas across the United States. Sediment-toxicity tests were conducted with the amphipod Hyalella azteca (28 day exposures) and with the midge Chironomus dilutus (10 day exposures). Overall, 33 % of the samples were toxic to amphipods and 12 % of the samples were toxic to midge based on comparisons with reference conditions within each study area. Significant correlations were observed between toxicity end points and sediment concentrations of trace elements, polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), or organochlorine (OC) pesticides; however, these correlations were typically weak, and contaminant concentrations were usually below sediment-toxicity thresholds. Concentrations of the pyrethroid bifenthrin exceeded an estimated threshold of 0.49 ng/g (at 1 % total organic carbon) in 14 % of the samples. Of the samples that exceeded this bifenthrin toxicity threshold, 79 % were toxic to amphipods compared with 25 % toxicity for the samples below this threshold. Application of mean probable effect concentration quotients (PECQs) based on measures of groups of contaminants (trace elements, total PAHs, total PCBs, OC pesticides, and pyrethroid pesticides [bifenthrin in particular]) improved the correct classification of samples as toxic or not toxic to amphipods compared with measures of individual groups of contaminants.

  1. The role of metabolism in the toxicity of 2,4,6-trinitrotoluene and its degradation products to the aquatic amphipod Hyalella azteca.

    Science.gov (United States)

    Sims, Jerre G; Steevens, Jeffery A

    2008-05-01

    Toxicological data on the effects of the explosive, 2,4,6-trinitrotoluene (TNT), and its degradation products suggests an unpredictable toxicological response in aquatic organisms. Several studies suggest TNT becomes more toxic as it degrades while others suggest TNT becomes less toxic. This study focused on the toxicity of TNT and several degradation products as well as the role of oxidative metabolism in the toxicity of TNT. The aquatic invertebrate Hyalella azteca was used to evaluate the toxicity of TNT and four of its degradation products. The most reduced degradation product, 2,4-diamino, 6-nitrotoluene (2,4-DANT) was the most toxic to H. azteca. However, 2,4-DANT was only a minor metabolite in H. azteca. The influence of metabolism on the toxicokinetics of TNT was assessed indirectly through the use of a CYP450 inducer and inhibitor. Treatment of organisms with beta-napthoflavone (BNF), a CYP450 inducer, increased the toxicity of TNT and increased the rate of elimination and metabolism of TNT. Similar to BNF, organisms treated with clotrimazole (CTZ), a CYP450 inhibitor, resulted in increased toxicity and TNT metabolism. It is likely the ability to metabolize or bioactivate TNT to a more reactive intermediate plays a significant role in the sensitivity of organisms to TNT.

  2. ACUTE AND CHRONIC TOXICITY OF ALUMINUM TO A UNIONID MUSSEL (LAMPSILIS SILIQUOIDEA) AND AN AMPHIPOD (HYALELLA AZTECA) IN WATER-ONLY EXPOSURES.

    Science.gov (United States)

    Wang, Ning; Ivey, Chris D; Brunson, Eric L; Cleveland, Danielle; Ingersoll, Chris G; Stubblefield, William A; Cardwell, Allison S

    2017-05-05

    The US Environmental Protection Agency (USEPA) is reviewing the protectiveness of the national ambient water quality criteria (WQC) for aluminum (Al) and compiling a toxicity dataset to update the WQC. Freshwater mussels are one of the most imperiled groups of animals in the world, but little is known about the sensitivity of mussels to Al. The objective of the present study was to evaluate acute 96-h and chronic 28-d toxicity of Al to a unionid mussel (Lampsilis siliquoidea) and a commonly tested amphipod (Hyalella azteca) at a pH of 6 and water hardness of 100 mg/L as CaCO3 . Acute 50% effect concentration (EC50) for survival of both species was >6,200 µg total Al/L. The EC50 was greater than all acute values in the USEPA acute Al dataset for freshwater species at pH range of 5.0 to azteca) as the 5th most sensitive species, indicating the two species were sensitive to Al in chronic exposures. The USEPA proposed acute and chronic WQC for Al would adequately protect the mussel and amphipod tested; however, inclusion of the chronic data from the present study and recalculation of the chronic criterion would likely lower the proposed chronic criterion. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

  3. Species diversity and phylogeographical affinities of the Branchiopoda (Crustacea) of Churchill, Manitoba, Canada.

    Science.gov (United States)

    Jeffery, Nicholas W; Elías-Gutiérrez, Manuel; Adamowicz, Sarah J

    2011-01-01

    The region of Churchill, Manitoba, contains a wide variety of habitats representative of both the boreal forest and arctic tundra and has been used as a model site for biodiversity studies for nearly seven decades within Canada. Much previous work has been done in Churchill to study the Daphnia pulex species complex in particular, but no study has completed a wide-scale survey on the crustacean species that inhabit Churchill's aquatic ecosystems using molecular markers. We have employed DNA barcoding to study the diversity of the Branchiopoda (Crustacea) in a wide variety of freshwater habitats and to determine the likely origins of the Churchill fauna following the last glaciation. The standard animal barcode marker (COI) was sequenced for 327 specimens, and a 3% divergence threshold was used to delineate potential species. We found 42 provisional and valid branchiopod species from this survey alone, including several cryptic lineages, in comparison with the 25 previously recorded from previous ecological works. Using published sequence data, we explored the phylogeographic affinities of Churchill's branchiopods, finding that the Churchill fauna apparently originated from all directions from multiple glacial refugia (including southern, Beringian, and high arctic regions). Overall, these microcrustaceans are very diverse in Churchill and contain multiple species complexes. The present study introduces among the first sequences for some understudied genera, for which further work is required to delineate species boundaries and develop a more complete understanding of branchiopod diversity over a larger spatial scale.

  4. Paleocene decapod Crustacea from northeastern Mexico: Additions to biostratigraphy and diversity

    Science.gov (United States)

    Martínez-Díaz, José Luis; Aguillón-Martínez, Martha Carolina; Luque, Javier; Vega, Francisco J.

    2017-03-01

    New decapod specimens from mid-Paleocene shallow marine deposits of NE Mexico represents an important addition to the diversity, paleobiogeography and evolution of the Crustacea record. In this work, we describe additions to the decapod assemblage from the Paleocene (Selandian) Rancho Nuevo Formation (Difunta Group, Parras Basin, Coahuila). Due to the evident size differences with other decapod assemblages, we compare the new assemblage with those from the Lower Paleocene (Danian) Mexia Clay Member of the Wills Point Formation, Texas, and the Lower Eocene (Ypresian) El Bosque Formation in Chiapas. Species reported from the mid-Paleocene (Selandian) assemblage of the Porters Creek Formation (Alabama), are correlatable to the decapod species from NE Mexico in age, size and systematic composition. The erymid lobster Enoploclytia gardnerae (Rathbun, 1935) is represented by several carapaces and chelae remains. One isolated palm of Callianassidae is included. Numerous carapaces of Linuparus wilcoxensis Rathbun, 1935 are described, representing the most abundant lobster. A new record for the raninid Notopoides sp., and presence of Quasilaeviranina sp. cf. arzignagnensis and Quasilaeviranina ovalis are here reported. New raninids, Claudioranina latacantha sp. nov. and Claudioranina sp. (Cyrtorhininae) are also part of this assemblage. Paraverrucoides alabamensis (Rathbun, 1935), and Tehuacana americana (Rathbun, 1935) are represented by several carapaces exhibiting intraspecific morphological variation. Different sizes among the Early and Middle Paleocene and Early Eocene decapod populations suggests a possible effect of variation in seawater temperatures and/or a Lilliput effect after the K/Pg event.

  5. Toxicity of imidacloprid to the terrestrial isopod Porcellio scaber (Isopoda, Crustacea).

    Science.gov (United States)

    Drobne, Damjana; Blazic, Mateja; Van Gestel, Cornelis A M; Leser, Vladka; Zidar, Primoz; Jemec, Anita; Trebse, Polonca

    2008-04-01

    Imidacloprid is a neonicotinoid insecticide with neurotoxic action that, as a possible alternative for commonly used organophosphorus pesticides, has gained registration in about 120 countries for use in over 140 agricultural crops. Only few data are available on its toxicity for soil invertebrates. We therefore assessed the effects of imidacloprid on survival, weight gain, feeding rate, total protein content, glutathione S-transferase activity (GST), and digestive gland epithelial thickness in juveniles and adults of the terrestrial isopod Porcellio scaber. After two weeks of feeding on imidacloprid-dosed food, weight gain (NOEC 5 microg/g dry food) and feeding rate (NOEC 10 microg/g) in juveniles, and feeding rate (NOECPorcellio scaber, Isopoda, Crustacea). Chemosphere 64, 1745-1752]. At actual environmental concentrations, diazinon poses a higher risk to P. scaber. Due to its increasing use in crop protection and higher persistence in soil, imidacloprid might however, be potentially more dangerous after long-term application. We conclude that toxicity testing with P. scaber provides relevant, repeatable, reproducible and comparable toxicity data that is useful for the risk assessment of pesticides in the terrestrial environment.

  6. Photon activation analysis of trace elements in several kinds of invertebrate animals. 1. Arthropoda crustacea

    Energy Technology Data Exchange (ETDEWEB)

    Fukushima, Michiko; Tamate, Hidetoshi [Ishinomaki Senshu Univ., Miyagi (Japan)

    1998-09-01

    Quantitative analysis of trace elements was made for marine mollusca by light quantum activation method. Crustacea which is likely to be well reflecting the environment of ocean floor was used as the subjects. Various kinds of these animals including Carcinus Portunus. Palinurus, Panulirus, Squilla etc. were collected from the sea off Japan to determine the concentrations of 15 kinds of elements in the gills, muscles, head/thorax region and viceraneous organs. The concentration of As was found markedly high in either of gills, muscles or viceraneous organs of Palinurus taken from the sea near Okinawa. It was found that there are no difference in the concentrations of As, Fe, Mn and Pb among the species studied and Fe, Mn and Pb were detected at high levels in the gills of Carcinus, whereas the Fe and Mn concentrations in the gills of Palinurus were considerably lower than other species tested. Thus, the element concentration was different among the regions studied and also species. (M.N.)

  7. The developmental trend of labrum and median eyes of Orsten-type preserved Phosphatocopina (Crustacea)

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    The Phosphatocopina (Crustacea,Arthropoda) is an important group of ’Orsten-type’ preserved fossils.It is resolved as the sister-group of Eucrustacea.Here we study the labrum,the median eyes,and the inner lamella of Phosphatocopina based on the selected specimens respectively from western Hunan,South China,and Sweden.The labrum characters of different species exhibit interspecific difference.The ratio of labrum length/shield length is significant to the reconstruction of the ontogeny of phosphatocopines.The labrum characters should be introduced to the diagnosis of Phosphatocopina.In the earliest growth stage,the median eyes were inconspicuous,almost as flat as the other area of the hypstome.However,with the growth of the individuals they became conspicuous.There were two obviously concave structures on the ventral side of the hypostome in later stages,which were the positions where the median eyes should have been located.In addition,the two modes of preservation of the inner lamella,i.e.,that of shrinking and that of bulging up,are interpreted as the preservational artifact herein.

  8. Benthic Crustacea from tropical and temperate reef locations: differences in assemblages and their relationship with habitat structure

    Science.gov (United States)

    Kramer, Michael J.; Bellwood, David R.; Taylor, Richard B.; Bellwood, Orpha

    2017-09-01

    Tropical and temperate marine habitats have long been recognised as fundamentally different system, yet comparative studies are rare, particularly for small organisms such as Crustacea. This study investigates the ecological attributes (abundance, biomass and estimated productivity) of benthic Crustacea in selected microhabitats from a tropical and a temperate location, revealing marked differences in the crustacean assemblages. In general, microhabitats from the tropical location (dead coral, the epilithic algal matrix [algal turfs] and sand) supported high abundances of small individuals (mean length = 0.53 mm vs. 0.96 mm in temperate microhabitats), while temperate microhabitats (the brown seaweed Carpophyllum sp., coralline turf and sand) had substantially greater biomasses of crustaceans and higher estimated productivity rates. In both locations, the most important microhabitats for crustaceans (per unit area) were complex structures: tropical dead coral and temperate Carpophyllum sp. It appears that the differences between microhabitats are largely driven by the size and relative abundance of key crustacean groups. Temperate microhabitats have a higher proportion of relatively large Peracarida (Amphipoda and Isopoda), whereas tropical microhabitats are dominated by small detrital- and microalgal-feeding crustaceans (harpacticoid copepods and ostracods). These differences highlight the vulnerability of tropical and temperate systems to the loss of complex benthic structures and their associated crustacean assemblages.

  9. Structure and Ultrastructure of the Endodermal Region of the Alimentary Tract in the Freshwater Shrimp Neocaridina heteropoda (Crustacea, Malacostraca.

    Directory of Open Access Journals (Sweden)

    Lidia Sonakowska

    Full Text Available The freshwater shrimp Neocaridina heteropoda (Crustacea, Malacostraca, Decapoda originates from Asia and is one of the species that is widely available all over the world because it is the most popular shrimp that is bred in aquaria. The structure and the ultrastructure of the midgut have been described using X-ray microtomography, transmission electron microscopy, light and fluorescence microscopes. The endodermal region of the alimentary system in N. heteropoda consists of an intestine and a hepatopancreas. No differences were observed in the structure and ultrastructure of males and females of the shrimp that were examined. The intestine is a tube-shaped organ and the hepatopancreas is composed of two large diverticles that are divided into the blind-end tubules. Hepatopancreatic tubules have three distinct zones - proximal, medial and distal. Among the epithelial cells of the intestine, two types of cells were distinguished - D and E-cells, while three types of cells were observed in the epithelium of the hepatopancreas - F, B and E-cells. Our studies showed that the regionalization in the activity of cells occurs along the length of the hepatopancreatic tubules. The role and ultrastructure of all types of epithelial cells are discussed, with the special emphasis on the function of the E-cells, which are the midgut regenerative cells. Additionally, we present the first report on the existence of an intercellular junction that is connected with the E-cells of Crustacea.

  10. Structure and Ultrastructure of the Endodermal Region of the Alimentary Tract in the Freshwater Shrimp Neocaridina heteropoda (Crustacea, Malacostraca).

    Science.gov (United States)

    Sonakowska, Lidia; Włodarczyk, Agnieszka; Poprawa, Izabela; Binkowski, Marcin; Śróbka, Joanna; Kamińska, Karolina; Kszuk-Jendrysik, Michalina; Chajec, Łukasz; Zajusz, Bartłomiej; Rost-Roszkowska, Magdalena Maria

    2015-01-01

    The freshwater shrimp Neocaridina heteropoda (Crustacea, Malacostraca, Decapoda) originates from Asia and is one of the species that is widely available all over the world because it is the most popular shrimp that is bred in aquaria. The structure and the ultrastructure of the midgut have been described using X-ray microtomography, transmission electron microscopy, light and fluorescence microscopes. The endodermal region of the alimentary system in N. heteropoda consists of an intestine and a hepatopancreas. No differences were observed in the structure and ultrastructure of males and females of the shrimp that were examined. The intestine is a tube-shaped organ and the hepatopancreas is composed of two large diverticles that are divided into the blind-end tubules. Hepatopancreatic tubules have three distinct zones - proximal, medial and distal. Among the epithelial cells of the intestine, two types of cells were distinguished - D and E-cells, while three types of cells were observed in the epithelium of the hepatopancreas - F, B and E-cells. Our studies showed that the regionalization in the activity of cells occurs along the length of the hepatopancreatic tubules. The role and ultrastructure of all types of epithelial cells are discussed, with the special emphasis on the function of the E-cells, which are the midgut regenerative cells. Additionally, we present the first report on the existence of an intercellular junction that is connected with the E-cells of Crustacea.

  11. Does long-term fungicide exposure affect the reproductive performance of leaf-shredders? A partial life-cycle study using Hyalella azteca.

    Science.gov (United States)

    Baudy, Patrick; Zubrod, Jochen P; Konschak, Marco; Weil, Mirco; Schulz, Ralf; Bundschuh, Mirco

    2017-03-01

    Leaf-shredding amphipods play a critical role in the ecosystem function of leaf litter breakdown, a key process in many low order streams. Fungicides, however, may adversely influence shredders' behavior and the functions they provide, while there is only limited knowledge concerning effects on their reproductive performance. To assess the latter, a semi-static 56-day partial life-cycle bioassay using the model shredder Hyalella azteca (n = 30) was performed applying two environmentally relevant concentrations of a model fungicide mixture (i.e., 5 and 25 μg/L) composed of five fungicides with different modes of toxic action. Variables related to the food processing (leaf consumption and feces production), growth (body length and dry weight), energy reserves (lipid content), and reproduction (amplexus pairs, number and length of offspring) were determined to understand potential implications in the organisms' energy budget. While the fungicides did not affect leaf consumption, both fungicide treatments significantly reduced amphipods' feces production (∼20%) compared to the control. This observation suggests an increased food utilization to counteract the elevated and stress-related energy demand: although growth as well as energy reserves were unaffected, amplexus pairs were less frequently observed in both fungicide treatments (∼50-100%) suggesting a tradeoff regarding energy allocation favoring the maintenance of fundamental functions at the organism level over reproduction. As a result, the time to release of first offspring was delayed in both fungicide treatments (7 and 14 days) and the median number of offspring was significantly lower in the 25-μg/L treatment (100%), whereas offspring length remained unaffected. The results of this study thus indicate that chronic fungicide exposures can negatively impact shredders' reproductive performance. This may translate into lower abundances and thus a reduced contribution to leaf litter breakdown in

  12. Using an interlaboratory study to revise methods for conducting 10-d to 42-d water or sediment toxicity tests with Hyalella azteca.

    Science.gov (United States)

    Ivey, Chris D; Ingersoll, Chris G; Brumbaugh, William G; Hammer, Edward J; Mount, Dave R; Hockett, J Russell; Norberg-King, Teresa J; Soucek, Dave; Taylor, Lisa

    2016-10-01

    Studies have been conducted to refine US Environmental Protection Agency, ASTM International, and Environment Canada standard methods for conducting 42-d reproduction tests with Hyalella azteca in water or in sediment. Modifications to the H. azteca method include better-defined ionic composition requirements for exposure water (i.e., >15 mg/L of chloride and >0.02 mg/L of bromide) and improved survival, growth, and reproduction with alternate diets provided as increased rations over time in water-only or whole-sediment toxicity tests. A total of 24 laboratories volunteered to participate in the present interlaboratory study evaluating the performance of H. azteca in 42-d studies in control sand or control sediment using the refined methods. Improved growth and reproduction of H. azteca was observed with 2 alternate diets of 1) ramped diatoms (Thalassiosira weissflogii) + ramped Tetramin or 2) yeast-cerophyll-trout chow (YCT) + ramped Tetramin, especially when compared with results from the traditional diet of 1.8 mg YCT/d. Laboratories were able to meet proposed test acceptability criteria and in most cases had lower variation in growth or reproduction compared with previous interlaboratory studies using the traditional YCT diet. Laboratory success in conducting 42-d H. azteca exposures benefited from adherence to several key requirements of the detailed testing, culturing, and handling methods. Results from the present interlaboratory study are being used to help revise standard methods for conducting 10-d to 42-d water or sediment toxicity exposures with H. azteca. Environ Toxicol Chem 2016;35:2439-2447. © 2016 SETAC.

  13. Implications of Cu and Ni toxicity in two members of the Hyalella azteca cryptic species complex: Mortality, growth, and bioaccumulation parameters.

    Science.gov (United States)

    Leung, Jessica; Witt, Jonathan D S; Norwood, Warren; Dixon, D George

    2016-11-01

    Hyalella azteca, an amphipod crustacean, is frequently used in freshwater toxicity tests. Since the mid-1980s, numerous organizations have collected and established cultures of H. azteca originating from localities across North America. However, H. azteca is actually a large cryptic species complex whose members satisfy both the biological and the phylogenetic species concepts. Genetic analysis at the mitochondrial COI gene has revealed that only 2 clades are cultured in 17 North American laboratories; however, there are 85 genetically divergent lineages within this complex in the wild. In the present study, 2 members (clades 1 and 8) of the H. azteca species complex were identified using the mitochondrial COI gene. These 2 clades were exposed to Cu or Ni for 14 d. A saturation-based mortality model and the general growth model were used to determine mortality (lethal concentration, 25% and 50% [LC25 and LC50], lethal body concentration, 25% and 50% [LBC25 and LBC50]) and growth (inhibitory concentration, 25% [IC25, IBC25]) endpoints, respectively. A modified saturation-based model was used to estimate metal bioaccumulation parameters. Clade 8 was significantly more tolerant than clade 1, with differences in LC50s. However, the effects of the metals on growth were not significantly different between clades, even though clade 1 was significantly larger than then clade 8. Differences in Cu or Ni bioaccumulation were not observed between clades 1 and 8. The differences in Cu and Ni LC50s may have implications for risk assessments, and it is recommended that toxicity experiments should only be performed with properly identified members of the H. azteca complex to maintain consistency among laboratories. Environ Toxicol Chem 2016;35:2817-2826. © 2016 SETAC.

  14. Do pyrethroid-resistant Hyalella azteca have greater bioaccumulation potential compared to non-resistant populations? Implications for bioaccumulation in fish.

    Science.gov (United States)

    Muggelberg, Leslie L; Huff Hartz, Kara E; Nutile, Samuel A; Harwood, Amanda D; Heim, Jennifer R; Derby, Andrew P; Weston, Donald P; Lydy, Michael J

    2017-01-01

    The recent discovery of pyrethroid-resistant Hyalella azteca populations in California, USA suggests there has been significant exposure of aquatic organisms to these terrestrially-applied insecticides. Since resistant organisms are able to survive in relatively contaminated habitats they may experience greater pyrethroid bioaccumulation, subsequently increasing the risk of those compounds transferring to predators. These issues were evaluated in the current study following toxicity tests in water with permethrin which showed the 96-h LC50 of resistant H. azteca (1670 ng L(-1)) was 53 times higher than that of non-resistant H. azteca (31.2 ng L(-1)). Bioaccumulation was compared between resistant and non-resistant H. azteca by exposing both populations to permethrin in water and then measuring the tissue concentrations attained. Our results indicate that resistant and non-resistant H. azteca have similar potential to bioaccumulate pyrethroids at the same exposure concentration. However, significantly greater bioaccumulation occurs in resistant H. azteca at exposure concentrations non-resistant organisms cannot survive. To assess the risk of pyrethroid trophic transfer, permethrin-dosed resistant H. azteca were fed to fathead minnows (Pimephales promelas) for four days, after which bioaccumulation of permethrin and its biotransformation products in fish tissues were measured. There were detectable concentrations of permethrin in fish tissues after they consumed dosed resistant H. azteca. These results show that bioaccumulation potential is greater in organisms with pyrethroid resistance and this increases the risk of trophic transfer when consumed by a predator. The implications of this study extend to individual fitness, populations and food webs.

  15. Validation of a new standardized test method for the freshwater amphipod Hyalella azteca: Determining the chronic effects of silver in sediment.

    Science.gov (United States)

    Taylor, Lisa N; Novak, Lesley; Rendas, Martina; Antunes, Paula M C; Scroggins, Rick P

    2016-10-01

    Environment Canada has developed a new 42-d sediment toxicity test method that includes a reproduction test endpoint with the freshwater amphipod Hyalella azteca. Because of concerns that existing standard methodologies, whereby adults are transferred to a water-only exposure before release of their first brood at day 28, will lead to internal contaminant depuration and loss of sensitivity, the Environment Canada methodology conducts the entire exposure in sediment. To demonstrate applicability of the method for assessing the toxicity of chemical-spiked sediment, H. azteca were exposed for 42 d to sediment amended with silver nitrate (AgNO3 ). Mortality was significantly higher at the highest sediment concentration of Ag (2088 mg/kg dry wt); however, there was no significant reduction in biomass or reproduction as a result of Ag exposure despite significant bioaccumulation. Based on Ag measurements and speciation modeling, the principle route of Ag exposure was likely through the ingestion of complexed colloidal or particulate Ag. The techniques used to recover young amphipods from sediment were critical, and although this effort can be labor intensive (20-45 min/replicate), the technicians demonstrated 91% recovery in blind trials. For the first time, Environment Canada will require laboratories to report their recovery proficiency for the 42-d test-without this information, data will not be accepted. Overall, the reproduction test will be more applicable when only a few chemical concentrations need to be evaluated in laboratory-amended sediments or for field-collected contaminated site assessments (i.e., contaminated site vs reference site comparisons). Environ Toxicol Chem 2016;35:2430-2438. © 2016 SETAC.

  16. Mixture toxicity of imidacloprid and cyfluthrin to two non-target species, the fathead minnow Pimephales promelas and the amphipod Hyalella azteca.

    Science.gov (United States)

    Lanteigne, Michelle; Whiting, Sara A; Lydy, Michael J

    2015-02-01

    Two species, the fathead minnow Pimephales promelas and the amphipod Hyalella azteca, were tested to examine acute toxicity to two insecticides, cyfluthrin and imidacloprid individually and as a mixture. Cyfluthrin was acutely toxic to P. promelas and H. azteca with EC50 values and 95 % confidence intervals of 0.31 µg L(-1) (0.26-0.35 µg L(-1)) and 0.0015 µg L(-1) (0.0011-0.0018 µg L(-1)), respectively. Imidacloprid was not acutely toxic to P. promelas at water concentrations ranging from 1 to 5000 µg L(-1), whereas it was toxic to H. azteca with a EC50 value of 33.5 µg L(-1) (23.3-47.4 µg L(-1)). For the P. promelas mixture test, imidacloprid was added at a single concentration to a geometric series of cyfluthrin concentrations bracketing the EC50 value. A synergistic ratio (SR) of 1.9 was found for P. promelas, which was calculated using the cyfluthrin-only exposure and mixture-exposure data. Because cyfluthrin and imidacloprid were toxic to H. azteca, the mixture test was designed based on an equipotent toxic unit method. Results from the mixture test indicated a model deviation ratio (MDR) of 1.7 or 2.7 depending on the model. Mixture test results from the simultaneous exposure to cyfluthrin and imidacloprid with both species indicated a greater than expected toxic response because the SR or MDR values were >1. Because these two insecticides are commonly used together in the same product formulations, nontarget species could be more affected due to their greater-than-additive toxicity observed in the current study.

  17. Direct and indirect toxicity of the fungicide pyraclostrobin to Hyalella azteca and effects on leaf processing under realistic daily temperature regimes.

    Science.gov (United States)

    Willming, Morgan M; Maul, Jonathan D

    2016-04-01

    Fungicides in aquatic environments can impact non-target bacterial and fungal communities and the invertebrate detritivores responsible for the decomposition of allochthonous organic matter. Additionally, in some aquatic systems daily water temperature fluctuations may influence these processes and alter contaminant toxicity, but such temperature fluctuations are rarely examined in conjunction with contaminants. In this study, the shredding amphipod Hyalella azteca was exposed to the fungicide pyraclostrobin in three experiments. Endpoints included mortality, organism growth, and leaf processing. One experiment was conducted at a constant temperature (23 °C), a fluctuating temperature regime (18-25 °C) based on field-collected data from the S. Llano River, Texas, or an adjusted fluctuating temperature regime (20-26 °C) based on possible climate change predictions. Pyraclostrobin significantly reduced leaf shredding and increased H. azteca mortality at concentrations of 40 μg/L or greater at a constant 23 °C and decreased leaf shredding at concentrations of 15 μg/L or greater in the fluctuating temperatures. There was a significant interaction between temperature treatment and pyraclostrobin concentration on H. azteca mortality, body length, and dry mass under direct aqueous exposure conditions. In an indirect exposure scenario in which only leaf material was exposed to pyraclostrobin, H. azteca did not preferentially feed on or avoid treated leaf disks compared to controls. This study describes the influence of realistic temperature variation on fungicide toxicity to shredding invertebrates, which is important for understanding how future alterations in daily temperature regimes due to climate change may influence the assessment of ecological risk of contaminants in aquatic ecosystems.

  18. Using an interlaboratory study to revise methods for conducting 10-d to 42-d water or sediment toxicity tests with Hyalella azteca

    Science.gov (United States)

    Ivey, Chris D.; Ingersoll, Christopher G.; Brumbaugh, William G.; Hammer, Edward J.; Mount, David R.; Hockett, J. Russell; Norberg-King, Teresa J.; Soucek, Dave; Taylor, Lisa

    2016-01-01

    Studies have been conducted to refine US Environmental Protection Agency, ASTM International, and Environment Canada standard methods for conducting 42-d reproduction tests with Hyalella azteca in water or in sediment. Modifications to the H. azteca method include better-defined ionic composition requirements for exposure water (i.e., >15 mg/L of chloride and >0.02 mg/L of bromide) and improved survival, growth, and reproduction with alternate diets provided as increased rations over time in water-only or whole-sediment toxicity tests. A total of 24 laboratories volunteered to participate in the present interlaboratory study evaluating the performance of H. azteca in 42-d studies in control sand or control sediment using the refined methods. Improved growth and reproduction of H. azteca was observed with 2 alternate diets of 1) ramped diatoms (Thalassiosira weissflogii) + ramped Tetramin or 2) yeast–cerophyll–trout chow (YCT) + ramped Tetramin, especially when compared with results from the traditional diet of 1.8 mg YCT/d. Laboratories were able to meet proposed test acceptability criteria and in most cases had lower variation in growth or reproduction compared with previous interlaboratory studies using the traditional YCT diet. Laboratory success in conducting 42-d H. azteca exposures benefited from adherence to several key requirements of the detailed testing, culturing, and handling methods. Results from the present interlaboratory study are being used to help revise standard methods for conducting 10-d to 42-d water or sediment toxicity exposures with H. azteca.

  19. Crustacea: Branchiura

    African Journals Online (AJOL)

    1993-03-25

    Mar 25, 1993 ... Mid-sagittal section through male 3,6 mm tot a] length. AM anterior midgut ..... The cuticle-I ined hindgut is a straight tube, 0,8 mm in length in a 3,6-mm ..... organs. preoral spine and digestive organs, Acta Univ. Lund. 13: 1-33.

  20. Arthropoda. Crustacea

    NARCIS (Netherlands)

    Böhm, Joh.

    1909-01-01

    Die mehrfach unterbrochene Kette tertiärer und jüngerer vulkanischer Gesteine, welche Java der Länge nach durchzieht, wird nordwärts und südwärts sowie in den Lücken von tertiären und quartären Ablagerungen eingerahmt ¹). Kreideformation und hoch krystalline Schiefer treten ganz vereinzelt und auf w

  1. Lysosomal membrane stability in laboratory- and field-exposed terrestrial isopods Porcellio scaber (Isopoda, Crustacea).

    Science.gov (United States)

    Nolde, Natasa; Drobne, Damjana; Valant, Janez; Padovan, Ingrid; Horvat, Milena

    2006-08-01

    Two established methods for assessment of the cytotoxicity of contaminants, the lysosomal latency (LL) assay and the neutral red retention (NRR) assay, were successfully applied to in toto digestive gland tubes (hepatopancreas) of the terrestrial isopod Porcellio scaber (Isopoda, Crustacea). In vitro exposure of isolated gland tubes to copper was used as a positive control to determine the performance of the two methods. Lysosomal latency and the NRR assay were then used on in vivo (via food) laboratory-exposed animals and on field populations. Arbitrarily selected criteria for determination of the fitness of P. scaber were set on the basis of lysosomal membrane stability (LMS) as assessed with in toto digestive gland tubes. Decreased LMS was detected in animals from all polluted sites, but cytotoxicity data were not in agreement with concentrations of pollutants. Lysosomal membrane stability in the digestive gland tubes of animals from an environment in Idrija, Slovenia that was highly polluted with mercury (260 microg/g dry wt food and 1,600 microg/g dry wt soil) was less affected than LMS in laboratory animals fed with 5 and 50 microg Hg/g dry weight for 3 d. This probably indicates tolerance of P. scaber to mercury in the mercury-polluted environment and/or lower bioavailability of environmental mercury. In animals from the vicinity of a thermal power plant with environmental mercury concentrations three to four orders of magnitude lower than those in Idrija, LMS was severely affected. In general, the LL assay was more sensitive than the NRR assay. The LMS assay conducted on digestive gland tubes of terrestrial isopods is highly recommended for integrated biomarker studies.

  2. Reduction and methylation of mercury in the terrestrial isopod Porcellio scaber (Crustacea) and its environment.

    Science.gov (United States)

    Nolde, Natasa; Drobne, Damjana; Horvat, Milena; Jereb, Vesna

    2005-07-01

    Reduction and methylation of inorganic mercury in Porcellio scaber (Isopoda, Crustacea) and its environment were studied, using a purpose-built experimental setup where Hg cycling was followed using 203Hg2+ tracer in experiments without and with isopods. In experiment without isopods, daily reduction of 203Hg2+ to 203Hg0 under sterile and nonsterile conditions was measured for three weeks to assess the contribution of bacteria to this process. In experiments with isopods, daily release of 203Hg0 was measured for two weeks. Total mercury (T203Hg) and monomethylmercury (Me203Hg) in whole animals, gut, digestive glands (hepatopancreas), food (hazelnut leaves), and feces were measured to obtain the assimilation and distribution of mercury in the animals, to investigate the origin and fate of Me203Hg, and, finally, to assess the mass balance of mercury in the experimental system. Experiment without isopods showed the important role of bacteria in reduction of 203Hg2+ to 203Hg0, especially in the first day of the experiment. Experiments with isopods showed that formation of 203Hg0 depended on the 203Hg2+ concentration in the food. The contribution of the isopod's digestive flora in reduction of 203Hg2+ to 203Hg0 was negligible. Approximately 3% of T203Hg and 2% of Me203Hg consumed was assimilated by the animals. Methylation of 203Hg2+ occurred already in the leaves before they were consumed by the isopods. Assimilation of Me203Hg from the food surprisingly was low. Also, a loss of Me203Hg was noticed when comparing assimilated and excreted Me203Hg versus consumed Me203Hg. This may be explained by the assumption that demethylation of MeHg prevailed over methylation of Hg2+ in the animal's digestive system, leading to excretion of ingested mercury as Hg2+.

  3. Cell Death in the Epithelia of the Intestine and Hepatopancreas in Neocaridina heteropoda (Crustacea, Malacostraca.

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    Lidia Sonakowska

    Full Text Available The endodermal region of the digestive system in the freshwater shrimp Neocaridina heteropoda (Crustacea, Malacostraca consists of a tube-shaped intestine and large hepatopancreas, which is formed by numerous blind-ended tubules. The precise structure and ultrastructure of these regions were presented in our previous studies, while here we focused on the cell death processes and their effect on the functioning of the midgut. We used transmission electron microscopy, light and confocal microscopes to describe and detect cell death, while a quantitative assessment of cells with depolarized mitochondria helped us to establish whether there is the relationship between cell death and the inactivation of mitochondria. Three types of the cell death were observed in the intestine and hepatopancreas-apoptosis, necrosis and autophagy. No differences were observed in the course of these processes in males and females and or in the intestine and hepatopancreas of the shrimp that were examined. Our studies revealed that apoptosis, necrosis and autophagy only involves the fully developed cells of the midgut epithelium that have contact with the midgut lumen-D-cells in the intestine and B- and F-cells in hepatopancreas, while E-cells (midgut stem cells did not die. A distinct correlation between the accumulation of E-cells and the activation of apoptosis was detected in the anterior region of the intestine, while necrosis was an accidental process. Degenerating organelles, mainly mitochondria were neutralized and eventually, the activation of cell death was prevented in the entire epithelium due to autophagy. Therefore, we state that autophagy plays a role of the survival factor.

  4. New distribution ranges and records of caridean shrimps (Crustacea: Decapoda: Caridea from the west coast of Mexico Nuevos intervalos de distribución y registros de camarones carideos (Crustacea: Decapoda: Caridea de la costa oeste de México

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    Michel E. Hendrickx

    2011-04-01

    Full Text Available Geographic records are presented for 24 species of Caridea (Crustacea: Decapoda along Pacific coast of Mexico, in the East Pacific. New records are presented for Psathyrocaris fragilis Wood-Mason, 1893 (from Peru to Mexico, Periclimenes infraspinis (Rathbun, 1902, Pontonia margarita Smith, 1869, Alpheus cristulifrons Rathbun, 1900, Alpheus umbo Kim & Abele, 1988, Automate rugosa Coutière, 1900, and Lysmata californica (Stimpson, 1866 (within the Gulf of California, and Typton hephaestus Holthuis, 1951 (from the Gulf of California to the Gulf of Tehuantepec, Mexico. Aditional records are given that establish the presence of species at intermediate localities within the Gulf of California and along the southwestern coast of Mexico.Se recolectaron especímenes de 24 especies de Caridea (Crustacea: Decapoda en la costa del Pacífico de México, en el Pacífico Este. Nuevos registros geográficos son señalados para Psathyrocaris fragilis Wood-Mason, 1893 (desde Perú hasta México, Periclimenes infraspinis (Rathbun, 1902, Pontonia margarita Smith, 1869, Alpheus cristulifrons Rathbun, 1900, Alpheus umbo Kim & Abele, 1988, Automate rugosa Coutière, 1900 y Lysmata californica (Stimpson, 1866 (en el Golfo de California y para Typton hephaestus Holthuis, 1951 (del Golfo de California hasta el Golfo de Tehuantepec, México. Se proporciona información adicional acerca de la presencia de algunas especies en localidades intermedias en el Golfo de California y a lo largo de la costa suroeste de México.

  5. Occurrence of the lessepsian species Portunus pelagicus (Crustacea and Apogon pharaonis (Pisces in the marine area of Rhodes Island

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    M. CORSINI-FOKA

    2004-06-01

    Full Text Available A large number of Red Sea species are colonizing the eastern Mediterranean Sea via the Suez Canal, mainly following the Anatolian coasts and spreading westwards. Portunus pelagicus is one of the most common Red Sea swimming crabs, first recorded in the Levantine Basin in 1898. Four specimens of P. pelagicus were collected in different marine areas of Rhodes Island from 1991 to 2000, while three specimens of the lessepsian fish Apogon pharaonis, first recorded in the Mediterranean in 1947, were caught during 2002 in the NW coast of Rhodes. The sub-tropical character of the marine area around Rhodes seems to facilitate the propagation of lessepsian species. These migrants have reached the island at different velocity and degree of establishment of their populations. The occurrence of the blue swimmer crab P. pelagicus and of the bullseye cardinal fish A. pharaonis increases the number of the decapod Crustacea and fish species of Red Sea origin observed in Greek waters.

  6. Occurrence of the lessepsian species Portunus pelagicus (Crustacea and Apogon pharaonis (Pisces in the marine area of Rhodes Island

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    M. CORSINI-FOKA

    2012-12-01

    Full Text Available A large number of Red Sea species are colonizing the eastern Mediterranean Sea via the Suez Canal, mainly following the Anatolian coasts and spreading westwards. Portunus pelagicus is one of the most common Red Sea swimming crabs, first recorded in the Levantine Basin in 1898. Four specimens of P. pelagicus were collected in different marine areas of Rhodes Island from 1991 to 2000, while three specimens of the lessepsian fish Apogon pharaonis, first recorded in the Mediterranean in 1947, were caught during 2002 in the NW coast of Rhodes. The sub-tropical character of the marine area around Rhodes seems to facilitate the propagation of lessepsian species. These migrants have reached the island at different velocity and degree of establishment of their populations. The occurrence of the blue swimmer crab P. pelagicus and of the bullseye cardinal fish A. pharaonis increases the number of the decapod Crustacea and fish species of Red Sea origin observed in Greek waters.

  7. Focused ion beam/scanning electron microscopy studies of Porcellio scaber (Isopoda, Crustacea) digestive gland epithelium cells.

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    Drobne, Damjana; Milani, Marziale; Zrimec, Alexis; Zrimec, Maja Berden; Tatti, Francesco; Draslar, Kazimir

    2005-01-01

    The focused ion beam (FIB) was used to prepare cross sections of precisely selected regions of the digestive gland epithelium of a terrestrial isopod P. scaber (Isopoda, Crustacea) for scanning electron microscopy (SEM). The FIB/SEM system allows ad libitum selection of a region for gross morphologic to ultrastructural investigation, as the repetition of FIB/SEM operations is unrestricted. The milling parameters used in our work proved to be satisfactory to produce serial two-dimensional (2-D) cuts and/or three-dimensional (3-D) shapes on a submicrometer scale. A final, cleaning mill at lower ion currents was employed to minimize the milling artifacts. After cleaning, the milled surface was free of filament- and ridge-like milling artifacts. No other effects of the cleaning mill were observed.

  8. Bioaccumulation in Porcellio scaber (Crustacea, Isopoda) as a measure of the EDTA remediation efficiency of metal-polluted soil.

    Science.gov (United States)

    Udovic, Metka; Drobne, Damjana; Lestan, Domen

    2009-10-01

    Leaching using EDTA applied to a Pb, Zn and Cd polluted soil significantly reduced soil metal concentrations and the pool of metals in labile soil fractions. Metal mobility (Toxicity Characteristic Leaching Procedure), phytoavailability (diethylenetriaminepentaacetic acid extraction) and human oral-bioavailability (Physiologically Based Extraction Test) were reduced by 85-92%, 68-91% and 88-95%, respectively. The metal accumulation capacity of the terrestrial isopod Porcellio scaber (Crustacea) was used as in vivo assay of metal bioavailability, before and after soil remediation. After feeding on metal contaminated soil for two weeks, P. scaber accumulated Pb, Zn and Cd in a concentration dependent manner. The amounts of accumulated metals were, however, higher than expected on the basis of extraction (in vitro) tests. The combined results of chemical extractions and the in vivo test with P. scaber provide a more relevant picture of the availability stripping of metals after soil remediation.

  9. Toxicity of uranium, molybdenum, nickel, and arsenic to Hyalella azteca and Chironomus dilutus in water-only and spiked-sediment toxicity tests.

    Science.gov (United States)

    Liber, Karsten; Doig, Lorne E; White-Sobey, Suzanne L

    2011-07-01

    A series of laboratory spiked-sediment toxicity tests with the amphipod Hyalella azteca and the midge Chironomus dilutus were undertaken to determine acute and chronic toxicity thresholds for uranium (U), molybdenum (Mo), nickel (Ni), and arsenic (As) based on both whole-sediment (total) and pore water exposure concentrations. Water-only toxicity data were also generated from separate experiments to determine the toxicities of these metals/metalloids under our test conditions and to help evaluate the hypothesis that pore water metal concentrations are better correlated with sediment toxicity to benthic organisms than whole-sediment metal concentrations. The relative toxicity of the four elements tested differed depending on which test species was used and whether whole-sediment or pore water metal concentrations were correlated with effects. Based on measured whole-sediment concentrations, Ni and As were the two most acutely toxic elements to H. azteca with 10-d LC50s of 521 and 532 mg/kg d.w., respectively. Measured pore water concentrations indicated that U and Ni were the two most acutely toxic elements, with 10-d LC50s to H. azteca of 2.15 and 2.05 mg/L, respectively. Based on pore water metal concentrations, the no-observed-effect concentrations (NOECs) for growth were (H. azteca and C. dilutus, respectively) 0.67 and 0.21 mg/L for U, azteca and C. dilutus, respectively) 2.99 and 0.48 mg/L for U, 0.37 and 2.33 mg/L for Ni, and 58.99 and 0.42 mg/L for As. For U and Ni, results from 96-h water-only acute toxicity tests correlated well with pore water metal concentrations in acutely toxic metal-spiked sediment. This was not true for As where metalloid concentrations in overlying water (diffusion from sediment) may have contributed to toxicity. The lowest whole-sediment LOEC reported here for As was 6.6- and 4-fold higher than the Canadian Council of Ministers of the Environment interim sediment quality guideline and the Canadian Nuclear Safety Commission (CNSC

  10. Sediment contamination of residential streams in the metropolitan Kansas City area, USA: Part II. Whole-sediment toxicity to the amphipod Hyalella azteca.

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    Tao, J; Ingersoll, C G; Kemble, N E; Dias, J R; Murowchick, J B; Welker, G; Huggins, D

    2010-10-01

    This is the second part of a study that evaluates the influence of nonpoint sources on the sediment quality of five adjacent streams within the metropolitan Kansas City area, central United States. Physical, chemical, and toxicity data (Hyalella azteca 28-day whole-sediment toxicity test) for 29 samples collected in 2003 were used for this evaluation, and the potential causes for the toxic effects were explored. The sediments exhibited a low to moderate toxicity, with five samples identified as toxic to H. azteca. Metals did not likely cause the toxicity based on low concentrations of metals in the pore water and elevated concentrations of acid volatile sulfide in the sediments. Although individual polycyclic aromatic hydrocarbons (PAHs) frequently exceeded effect-based sediment quality guidelines [probable effect concentrations (PECs)], only four of the samples had a PEC quotient (PEC-Q) for total PAHs over 1.0 and only one of these four samples was identified as toxic. For the mean PEC-Q for organochlorine compounds (chlordane, dieldrin, sum DDEs), 4 of the 12 samples with a mean PEC-Q above 1.0 were toxic and 4 of the 8 samples with a mean PEC-Q above 3.0 were toxic. Additionally, four of eight samples were toxic, with a mean PEC-Q above 1.0 based on metals, PAHs, polychlorinated biphenyls (PCBs), and organochlorine pesticides. The increase in the incidence of toxicity with the increase in the mean PEC-Q based on organochlorine pesticides or based on metals, PAHs, PCBs, and organochlorine pesticides suggests that organochlorine pesticides might have contributed to the observed toxicity and that the use of a mean PEC-Q, rather than PEC-Qs for individual compounds, might be more informative in predicting toxic effects. Our study shows that stream sediments subject to predominant nonpoint sources contamination can be toxic and that many factors, including analysis of a full suite of PAHs and pesticides of both past and present urban applications and the origins of

  11. Contaminants in stream sediments from seven United States metropolitan areas: part II—sediment toxicity to the amphipod Hyalella azteca and the midge Chironomus dilutus

    Science.gov (United States)

    Kemble, Nile E.; Hardesty, Douglas K.; Ingersoll, Christopher G.; Kunz, James L.; Sibley, Paul K.; Calhoun, Daniel L.; Gilliom, Robert J.; Kuivila, Kathryn; Nowell, Lisa H.; Moran, Patrick W.

    2013-01-01

    Relationships between sediment toxicity and sediment chemistry were evaluated for 98 samples collected from seven metropolitan study areas across the United States. Sediment-toxicity tests were conducted with the amphipod Hyalella azteca (28 day exposures) and with the midge Chironomus dilutus (10 day exposures). Overall, 33 % of the samples were toxic to amphipods and 12 % of the samples were toxic to midge based on comparisons with reference conditions within each study area. Significant correlations were observed between toxicity end points and sediment concentrations of trace elements, polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), or organochlorine (OC) pesticides; however, these correlations were typically weak, and contaminant concentrations were usually below sediment-toxicity thresholds. Concentrations of the pyrethroid bifenthrin exceeded an estimated threshold of 0.49 ng/g (at 1 % total organic carbon) in 14 % of the samples. Of the samples that exceeded this bifenthrin toxicity threshold, 79 % were toxic to amphipods compared with 25 % toxicity for the samples below this threshold. Application of mean probable effect concentration quotients (PECQs) based on measures of groups of contaminants (trace elements, total PAHs, total PCBs,OCpesticides, and pyrethroid pesticides [bifenthrin in particular]) improved the correct classification of samples as toxic or not toxic to amphipods compared with measures of individual groups of contaminants. Sediments are a repository for many contaminants released into surface waters. Because of this, organisms inhabiting sediments may be exposed to a wide range of contaminants (United States Environmental Protection Agency (USEPA) United States Environmental Protection Agency 2000; American Society for Testing and Materials [ASTM] American Society for Testing and Materials International 2012). Contaminants of potential concern in sediments typically include trace elements (metals

  12. Acute and chronic toxicity of imidacloprid to the aquatic invertebrates Chironomus tentans and Hyalella azteca under constant- and pulse-exposure conditions.

    Science.gov (United States)

    Stoughton, Sarah J; Liber, Karsten; Culp, Joseph; Cessna, Allan

    2008-05-01

    The toxicity of imidacloprid, a nicotinic mimic insecticide, to the aquatic invertebrates Chironomus tentans and Hyalella azteca, was first evaluated in static 96-hour tests using both technical material (99.2% pure) and Admire, a commercially available formulated product (240 g a.i. L(-1)). The 96-h lethal concentration (LC)50 values for technical imidacloprid and Admire were 65.43 and 17.44 microg/L, respectively, for H. azteca, and 5.75 and 5.40 microg/L, respectively, for C. tentans. Admire was subsequently used in 28-day chronic tests with both species. Exposure scenarios consisted of a constant- and a pulse-exposure regime. The pulse exposure lasted for four days, after which time the animals were transferred to clean water for the remaining 24 days of the study. Assessments were made on both day 10 and day 28. In the C. tentans under constant exposure, larval growth on day 10 was significantly reduced at 3.57 microg/L imidacloprid, the lowest-observed-effect concentration (LOEC). The no-observed-effect concentration (NOEC) and LOEC for the 28-day exposure duration (adult survival and emergence) were 1.14 and greater than 1.14 mug/L, respectively; the associated LC50 and LC25 were 0.91 and 0.59 microg/L, respectively. The LOEC for the pulse treatment was greater than 3.47 microg/L, but the day 10 LC25 was 3.03 microg/L. In the H. azteca tests, the day 10 and 28 constant exposure, as well as the day 28 pulse exposure, LOEC (survival) values were similar at 11.95, 11.46, and 11.93 microg/L, respectively. The day 10 and 28 constant exposure effective concentration (EC)25s (dry weight) were also similar, at 6.22 and 8.72 microg/L, respectively, but were higher than the pulse-exposure day 10 LOEC and EC25 (dry weight) values of 3.53 and 2.22 microg/L, respectively. Overall, C. tentans was more sensitive to acute and chronic imidacloprid exposure, but less sensitive to a single pulse, than H. azteca. Chronic, low-level exposure to imidacloprid may therefore reduce

  13. Sediment contamination of residential streams in the metropolitan kansas city area, USA: Part II. whole-sediment toxicity to the amphipod hyalella azteca

    Science.gov (United States)

    Tao, J.; Ingersoll, C.G.; Kemble, N.E.; Dias, J.R.; Murowchick, J.B.; Welker, G.; Huggins, D.

    2010-01-01

    This is the second part of a study that evaluates the influence of nonpoint sources on the sediment quality of five adjacent streams within the metropolitan Kansas City area, central United States. Physical, chemical, and toxicity data (Hyalella azteca 28-day whole-sediment toxicity test) for 29 samples collected in 2003 were used for this evaluation, and the potential causes for the toxic effects were explored. The sediments exhibited a low to moderate toxicity, with five samples identified as toxic to H. azteca. Metals did not likely cause the toxicity based on low concentrations of metals in the pore water and elevated concentrations of acid volatile sulfide in the sediments. Although individual polycyclic aromatic hydrocarbons (PAHs) frequently exceeded effect-based sediment quality guidelines [probable effect concentrations (PECs)], only four of the samples had a PEC quotient (PEC-Q) for total PAHs over 1.0 and only one of these four samples was identified as toxic. For the mean PEC-Q for organochlorine compounds (chlordane, dieldrin, sum DDEs), 4 of the 12 samples with a mean PEC-Q above 1.0 were toxic and 4 of the 8 samples with a mean PEC-Q above 3.0 were toxic. Additionally, four of eight samples were toxic, with a mean PEC-Q above 1.0 based on metals, PAHs, polychlorinated biphenyls (PCBs), and organochlorine pesticides. The increase in the incidence of toxicity with the increase in the mean PEC-Q based on organochlorine pesticides or based on metals, PAHs, PCBs, and organochlorine pesticides suggests that organochlorine pesticides might have contributed to the observed toxicity and that the use of a mean PEC-Q, rather than PEC-Qs for individual compounds, might be more informative in predicting toxic effects. Our study shows that stream sediments subject to predominant nonpoint sources contamination can be toxic and that many factors, including analysis of a full suite of PAHs and pesticides of both past and present urban applications and the origins of

  14. Variation in the toxicity of sediment-associated substituted phenylamine antioxidants to an epibenthic (Hyalella azteca) and endobenthic (Tubifex tubifex) invertebrate.

    Science.gov (United States)

    Prosser, R S; Bartlett, A J; Milani, D; Holman, E A M; Ikert, H; Schissler, D; Toito, J; Parrott, J L; Gillis, P L; Balakrishnan, V K

    2017-08-01

    Substituted phenylamine antioxidants (SPAs) are produced in relatively high volumes and used in a range of applications (e.g., rubber, polyurethane); however, little is known about their toxicity to aquatic biota. Therefore, current study examined the effects of chronic exposure (28 d) to four sediment-associated SPAs on epibenthic (Hyalella azteca) and endobenthic (Tubifex tubifex) organisms. In addition, acute (96-h), water-only exposures were conducted with H. azteca. Mortality, growth and biomass production were assessed in juvenile H. azteca exposed to diphenylamine (DPA), N-phenyl-1-napthylamine (PNA), N-(1,3-dimethylbutyl)-N'-phenyl-1,4-phenylenediamine (DPPDA), or 4,4'-methylene-bis[N-sec-butylaniline] (MBA). Mortality of adult T. tubifex and reproduction were assessed following exposure to the four SPAs. The 96-h LC50s for juvenile H. azteca were 1443, 109, 250, and >22 μg/L and 28-d LC50s were 22, 99, 135, and >403 μg/g dry weight (dw) for DPA, PNA, DPPDA, and MBA, respectively. Reproductive endpoints for T. tubifex (EC50s for production of juveniles > 500 μm: 15, 9, 4, 3.6 μg/g dw, for DPA, PNA, DPPDA, and MBA, respectively) were an order of magnitude more sensitive than endpoints for juvenile H. azteca and mortality of adult worms. The variation in toxicity across the four SPAs was likely related to the bioavailability of the sediment-associated chemicals, which was determined by the chemical properties of the SPAs (e.g., solubility in water, Koc). The variation in the sensitivity between the two species was likely due to differences in the magnitude of exposure, which is a function of the life histories of the epibenthic amphipod and the endobenthic worm. The data generated from this study will support effect characterization for ecological risk assessment. Crown Copyright © 2017. Published by Elsevier Ltd. All rights reserved.

  15. Evolution and phylogeny of the mud shrimps (Crustacea: Decapoda revealed from complete mitochondrial genomes

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    Lin Feng-Jiau

    2012-11-01

    Full Text Available Abstract Background The evolutionary history and relationships of the mud shrimps (Crustacea: Decapoda: Gebiidea and Axiidea are contentious, with previous attempts revealing mixed results. The mud shrimps were once classified in the infraorder Thalassinidea. Recent molecular phylogenetic analyses, however, suggest separation of the group into two individual infraorders, Gebiidea and Axiidea. Mitochondrial (mt genome sequence and structure can be especially powerful in resolving higher systematic relationships that may offer new insights into the phylogeny of the mud shrimps and the other decapod infraorders, and test the hypothesis of dividing the mud shrimps into two infraorders. Results We present the complete mitochondrial genome sequences of five mud shrimps, Austinogebia edulis, Upogebia major, Thalassina kelanang (Gebiidea, Nihonotrypaea thermophilus and Neaxius glyptocercus (Axiidea. All five genomes encode a standard set of 13 protein-coding genes, two ribosomal RNA genes, 22 transfer RNA genes and a putative control region. Except for T. kelanang, mud shrimp mitochondrial genomes exhibited rearrangements and novel patterns compared to the pancrustacean ground pattern. Each of the two Gebiidea species (A. edulis and U. major and two Axiidea species (N. glyptocercus and N. thermophiles share unique gene order specific to their infraorders and analyses further suggest these two derived gene orders have evolved independently. Phylogenetic analyses based on the concatenated nucleotide and amino acid sequences of 13 protein-coding genes indicate the possible polyphyly of mud shrimps, supporting the division of the group into two infraorders. However, the infraordinal relationships among the Gebiidea and Axiidea, and other reptants are poorly resolved. The inclusion of mt genome from more taxa, in particular the reptant infraorders Polychelida and Glypheidea is required in further analysis. Conclusions Phylogenetic analyses on the mt genome

  16. Estudios sobre los Entomostráceos de Colombia.V. Limnadia Orinoquiensis, una nueva especie de la familia Limnadiidae Sars, 1896 (Arthropoda, Crustacea, Conchostraca Estudios sobre los Entomostráceos de Colombia.V. Limnadia Orinoquiensis, una nueva especie de la familia Limnadiidae Sars, 1896 (Arthropoda, Crustacea, Conchostraca

    Directory of Open Access Journals (Sweden)

    Roessler Ewald W.

    1991-06-01

    Full Text Available En el presente estudio se describen rasgos morfológicos de una nueva especie colombiana del género Limnadia Brongniart, 1820, Limnadia orinoquiensis (Arthropoda, Crustacea, Conchostraca. La forma es de reproducción bisexual y típica para las aguas ácidas y oscuras de los alrededores de Puerto Inírida, Comisaria del Guainía. The present study describes morfological features of a new colombian species of the genus Limnadia Brongniart, 1820, Limnadia orinoquiensis (Arthropoda, Crustacea, Conchostraca, a species of bisexual reproduction, typical to the dark waters of temporary pools in the surroundings of Puerto Inírida, Comisaria of Guainía.

  17. Evaluation of the haematological parameters in Piaractus mesopotamicus Holmberg (Osteichthyes, Characidae with Argulus sp. (Crustacea, Branchiura infestation and treatment with organophosphate

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    Marcos Tavares-Dias

    1999-06-01

    Full Text Available Haematological parameters as erythrocytes, leukocytes and plasma glucose in Piaractus mesopotamicus Holmberg, 1887 were analyzed. Fish were parasitized with Argulus sp. (Crustacea, Branchiura and treated with 0.4 mg of thriclorphon 500/L water. The effects of parasitism and the action of the treatment were evaluated. Parasitized fish showed greater number of monocytes (P>0.05 and special granulocitic cells (P0.05. Organophosphate treatment presented significantly reduction (P>0.05 in red blood cells (RBC and hemoglobin.

  18. Petalophthalmus papilloculatus sp. nov. (Crustacea: Mysida: Petalophthalmidae), a new bathyal suprabenthic mysid from the Galicia Bank (NE Atlantic Ocean).

    Science.gov (United States)

    Vicente, Carlos San; Frutos, Inmaculada; Cartes, Joan E

    2014-02-14

    A new species of the genus Petalophthalmus (Crustacea: Mysida: Petalophthalmidae) is described, based on specimens collected from the Galicia Bank (northeastern Atlantic Ocean). This species can be distinguished from the other species of the genus Petalophthalmus by the presence of an ocular papilla on its eyes. P. papilloculatus sp. nov. is morphologically close to the cosmopolitan species P. armiger Willemoes-Suhm, 1875, but can be easily distinguished by the presence of an ocular papilla, the longer antennal scales bearing an apical lobe, the unique chitinous ridge on the molar process, the outwards lengthening of the three cuspidate setae on the outer margin of the uropodal exopod and the armature of the telson. This new species lives on fine and very fine sandy bottoms at the bank flanks, between 1536 and 1809 m depths. Probably related to the special biogeographic characteristics of seamounts, the morphological affinity between the new species and P. armiger supports the hypothesis on a common ancestry and recent divergence between both deep sea mysids. An identification key to world species of Petalophthalmus is provided.

  19. A new late Eocene Bicornucythere species (Ostracoda, Crustacea) from Myanmar, and its significance for the evolutionary history of the genus.

    Science.gov (United States)

    Yamaguchi, Tatsuhiko; Suzuki, Hisashi; Soe, Aung-Naing; Htike, Thaung; Nomura, Ritsuo; Takai, Masanaru

    2015-02-17

    The ostracode genus Bicornucythere (Ostracoda, Crustacea) is abundant in modern-day eutrophic marine bays, and is widely distributed in estuaries and inner bays throughout East Asia, including in China, Korea, Japan, and the Russian Far East. The evolutionary history of Bicornucythere is poorly understood. Here, we report on a new species of Bicornucythere (Bicornucythere concentrica sp. nov.) from the upper Eocene Yaw Formation in the Central Myanmar Basin. The oldest previously known Bicornucythere taxon, Bicornucythere secedens, was reported from lower Miocene strata in India, although a molecular phylogeny suggests that the genus first appeared in the Late Cretaceous. Bicornucythere concentrica sp. nov. is at least 10.9 million years older than the earliest known B. secedens. The new species occurs with Ammonia subgranulosa, a benthic foraminifer, an association that is representative of brackish water conditions in modern Asian bays. Our findings indicate that extant genera have inhabited Asian bays since the late Eocene. The paleobiogeography of Bicornucythere indicates that the taxon was dispersed onto Indian coasts during the collision between the Indian and Eurasian plates.

  20. Prolonged feeding of terrestrial isopod (Porcellio scaber, Isopoda, Crustacea) on TiO (2) nanoparicles. Absence of toxic effect.

    Science.gov (United States)

    Novak, Sara; Drobne, Damjana; Menard, Anja

    2012-01-01

    Nanoparticles of titanium dioxide are one of most widely used nanomaterials in different products in everyday use and in industry, but very little is known about their effects on non- target cells and tissues. Terrestrial isopods were exposed to food dosed with nano-TiO(2) to give final nominal concentration 1000 and 2000 µg TiO(2)/g dry weight of food. The effects of ingested nano-TiO(2) on the model invertebrate Porcellio scaber (Isopoda, Crustacea) after short-term (3 and 7 days) and prolonged (14 and 28 days) dietary exposure was assessed by conventional toxicity measures such as feeding rate, weight change and mortality. Cell membrane destabilization was also investigated. No severe toxicity effects were observed after 3, 7, 14 or 28 days of dietary exposure to nano-TiO(2), but some animals, particularly those exposed to lower concentrations of nanoparticles, had severely destabilized digestive cell membranes. It was concluded that strong destabilization of the cell membrane was sporadic, and neither concentration- nor time-related. Further research is needed to confirm this sporadic toxic effect of nanoparticles.

  1. Prolonged feeding of terrestrial isopod (Porcellio scaber, Isopoda, Crustacea on TiO2 nanoparicles. Absence of toxic effect

    Directory of Open Access Journals (Sweden)

    Sara Novak

    2012-03-01

    Full Text Available Nanoparticles of titanium dioxide are one of most widely used nanomaterials in different products in everyday use and in industry, but very little is known about their effects on non- target cells and tissues. Terrestrial isopods were exposed to food dosed with nano-TiO2 to give final nominal concentration 1000 and 2000 µg TiO2/g dry weight of food. The effects of ingested nano-TiO2 on the model invertebrate Porcellio scaber (Isopoda, Crustacea after short-term (3 and 7 days and prolonged (14 and 28 days dietary exposure was assessed by conventional toxicity measures such as feeding rate, weight change and mortality. Cell membrane destabilization was also investigated. No severe toxicity effects were observed after 3, 7, 14 or 28 days of dietary exposure to nano-TiO2, but some animals, particularly those exposed to lower concentrations of nanoparticles, had severely destabilized digestive cell membranes. It was concluded that strong destabilization of the cell membrane was sporadic, and neither concentration- nor time-related. Further research is needed to confirm this sporadic toxic effect of nanoparticles.

  2. Linkage of biomarkers along levels of biological complexity in juvenile and adult diazinon fed terrestrial isopod (Porcellio scaber, Isopoda, Crustacea).

    Science.gov (United States)

    Stanek, Katja; Drobne, Damjana; Trebse, Polonca

    2006-09-01

    In parallel laboratory experiments, we determined the effect of a typical representative of organophosphorous pesticides, diazinon, on AChE activity, lipid, protein and glycogen content, weight change, feeding activity and mortality of juvenile and adult terrestrial isopods Porcellio scaber (Isopoda, Crustacea). Organophosphorous pesticides (OP) are among the most extensively used pesticides, which have replaced organochlorine pesticides. OPs inhibit the enzyme acetylcholinesterase (AChE), resulting in neurotoxicity. They have more widespread effects on non-target organisms than do organochlorine pesticides. The aim of this study was to link effect of diazinon on target enzyme to energy reserves and to integrated biomarker responses in juvenile and adult P. scaber. The non-observed effect concentration (NOEC) for AChE activity after diazinon exposure in two weeks toxicity study with isopods was below 5 microg/g diazinon. There was a good agreement between concentrations at which AChE and survival were affected (10 microg/g diazinon in juveniles, 100 microg/g diazinon in adults). We revealed a link among AChE activity, protein content and mortality. Glycogen and lipid content, feeding activity and weight change were not affected in two weeks diazinon exposure up to 100 microg/g diazinon. Juveniles were affected at concentrations that were an order of magnitude lower than those provoking similar effects on adults. Recommendations are made for future toxicity studies with terrestrial isopods.

  3. "Candidatus Bacilloplasma," a novel lineage of Mollicutes associated with the hindgut wall of the terrestrial isopod Porcellio scaber (Crustacea: Isopoda).

    Science.gov (United States)

    Kostanjsek, Rok; Strus, Jasna; Avgustin, Gorazd

    2007-09-01

    Pointed, rod-shaped bacteria colonizing the cuticular surface of the hindgut of the terrestrial isopod crustacean Porcellio scaber (Crustacea: Isopoda) were investigated by comparative 16S rRNA gene sequence analysis and electron microscopy. The results of phylogenetic analysis, and the absence of a cell wall, affiliated these bacteria with the class Mollicutes, within which they represent a novel and deeply branched lineage, sharing less than 82.6% sequence similarity to known Mollicutes. The lineage has been positioned as a sister group to the clade comprising the Spiroplasma group, the Mycoplasma pneumoniae group, and the Mycoplasma hominis group. The specific signature sequence was identified and used as a probe in in situ hybridization, which confirmed that the retrieved sequences originate from the attached rod-shaped bacteria from the hindgut of P. scaber and made it possible to detect these bacteria in their natural environment. Scanning and transmission electron microscopy revealed a spherically shaped structure at the tapered end of the rod-shaped bacteria, enabling their specific and exclusive attachment to the tip of the cuticular spines on the inner surface of the gut. Specific adaptation to the gut environment, as well as phylogenetic positioning, indicate the long-term association and probable coevolution of the bacteria and the host. Taking into account their pointed, rod-shaped morphology and their phylogenetic position, the name "Candidatus Bacilloplasma" has been proposed for this new lineage of bacteria specifically associated with the gut surface of P. scaber.

  4. Bioaccumulation in Porcellio scaber (Crustacea, Isopoda) as a measure of the EDTA remediation efficiency of metal-polluted soil

    Energy Technology Data Exchange (ETDEWEB)

    Udovic, Metka [Centre for Soil and Environmental Science, Department of Agronomy, Biotechnical Faculty, University of Ljubljana, Jamnikarjeva 101, Sl-1000 Ljubljana (Slovenia); Drobne, Damjana [Department of Biology, Biotechnical Faculty, University of Ljubljana, Vecna pot 111, SI-1000 Ljubljana (Slovenia); Lestan, Domen, E-mail: domen.lestan@bf.uni-lj.s [Centre for Soil and Environmental Science, Department of Agronomy, Biotechnical Faculty, University of Ljubljana, Jamnikarjeva 101, Sl-1000 Ljubljana (Slovenia)

    2009-10-15

    Leaching using EDTA applied to a Pb, Zn and Cd polluted soil significantly reduced soil metal concentrations and the pool of metals in labile soil fractions. Metal mobility (Toxicity Characteristic Leaching Procedure), phytoavailability (diethylenetriaminepentaacetic acid extraction) and human oral-bioavailability (Physiologically Based Extraction Test) were reduced by 85-92%, 68-91% and 88-95%, respectively. The metal accumulation capacity of the terrestrial isopod Porcellio scaber (Crustacea) was used as in vivo assay of metal bioavailability, before and after soil remediation. After feeding on metal contaminated soil for two weeks, P. scaber accumulated Pb, Zn and Cd in a concentration dependent manner. The amounts of accumulated metals were, however, higher than expected on the basis of extraction (in vitro) tests. The combined results of chemical extractions and the in vivo test with P. scaber provide a more relevant picture of the availability stripping of metals after soil remediation. - Bioaccumulation tests with Porcellio scaber isopods are proposed as a supplement to chemical extraction in assessing metal bioavailability before and after soil remediation.

  5. Behavioural and Physiological Implications of a Burrow-dwelling Lifestyle for Two Species of Upogebiid Mud-shrimp (Crustacea: Thalassinidea)

    Science.gov (United States)

    Astall, C. M.; Taylor, A. C.; Atkinson, R. J. A.

    1997-02-01

    Upogebia stellataand U. deltaura(Crustacea: Thalassinidea) construct burrows in nearshore sediments in U.K. waters. Burrow structure is similar in both species; the basic burrow consisting of a two-opening, U-shaped section with a vertical shaft descending from the mid-point of the U. This structure may be variously elaborated. Burrow cross-section is circular, dilations allow turning by somersaulting and surface openings are often constricted. Conditions within the burrows are usually hypoxic and hypercapnic. Burrow water PO 2in the parts normally occupied by the mud-shrimp was between 80-110 Torr, but was much lower (10-45 Torr) in the deepest, poorly-irrigated parts. Both species irrigate their burrows by episodes of pleopod beating of variable duration (mean=8·5±3·5 min and 2·8±0·5 min for U. deltauraand U. stellata, respectively), which draws oxygenated water into the burrow and also particulate food for suspension feeding. When exposed to hypoxia, U. deltauraand U. stellatawere able to maintain their rates of oxygen consumption approximately constant over a wide range of PO 2( Pc=30-50 Torr). Under these conditions, there was a pronounced increase in scaphognathite beat rate but heart rate remained relatively constant. Below the Pc, however, both rates declined.

  6. Reproductive biology and seasonality of the Indo-Australasian mysid Mesopodopsis orientalis (Crustacea: Mysida) in a tropical mangrove estuary, Malaysia

    Science.gov (United States)

    Hanamura, Yukio; Siow, Ryon; Chee, Phaik-Ean

    2008-04-01

    A year-round survey of the tropical shallow-water mysid Mesopodopsis orientalis (Tattersall, 1908) (Crustacea, Mysidacea) was conducted in the Merbok mangrove estuary, northwestern Peninsular Malaysia. The mysid formed dense aggregations at the river's edge close to the mangrove forest during the daytime, but very few were captured elsewhere in the estuary system. The sampled population was found in a wide range of salinities from 16 to 32, demonstrating broad euryhalinity, and the number of the catch at the littoral zone ranged from 11.8 to 2273 ind m -2. The overall annual mean was 709.2 ind m -2. Females predominated over males in the entire population, and brooding females were present at every monthly sample, indicating that reproduction is continuous year round. The clutch size positively correlated with female body length. The diameter of eggs (Stage I embryos) was unaffected by the seasonality and independent of the maternal size within an observed size range. The life history pattern of the estuarine population of M. orientalis showed close similarity to that of the coastal counterpart. However, the former was found to produce fewer but larger eggs, and the specimens in this population were larger than those in the coastal population at the embryo, juvenile, and adult stages. This evidence indicates that the life history features of the estuarine population would differ to some degree from those of the coastal counterpart.

  7. Crustacea Decapoda captured through a passive collection in a stretch of Rio dos Mangues (Porto Seguro – Bahia – Brazil

    Directory of Open Access Journals (Sweden)

    Rafael Ribeiro Teixeira

    2012-11-01

    Full Text Available This paper aimed to carry out, through passive collection, a survey of Crustacea Decapoda species present in a stretch of Rio dos Mangues (Porto Seguro – Bahia – Brazil, during spring season of 2009. The collections were carried out in five sites, distributed over the final 10km of the river, using traps containing biological bait left underwater for 15h. To assess the abiotic variables, temperature, pH, and conductivity values were measured. A total of 135 individuals was registered, belonging to three species: the shrimps Macrobrachium acanthurus (Wiegmann, 1836 and M. olfersi (Wiegman, 1836, besides the crab Trichodactylus fluviatilis Latreille, 1828. In addition to these, two other crab species were collected: Goniopsis cruentata (Latreille, 1803 and Panopeus lacustris Desbonne, 1867. The highest values were registered in P4 (34.07% of individuals, P1 (23.70%, and P3 (22.96%. Temperature and pH presented a small variation throughout the analyses (respectively, 5.1-5.8 and 25.7-29.1°C. In turn, conductivity differed the estuary point (P5 from the other ones (respectively, 886mS and 41-48mS. No individual was registered in P2. The distribution of species was related to the type of microhabitat and the habit of each of them.

  8. The effect of starvation and re-feeding on mitochondrial potential in the midgut of Neocaridina davidi (Crustacea, Malacostraca)

    Science.gov (United States)

    Włodarczyk, Agnieszka; Sonakowska, Lidia; Kamińska, Karolina; Marchewka, Angelika; Wilczek, Grażyna; Wilczek, Piotr; Student, Sebastian; Rost-Roszkowska, Magdalena

    2017-01-01

    The midgut in the freshwater shrimp Neocaridina davidi (previously named N. heteropoda) (Crustacea, Malacostraca) is composed of a tube-shaped intestine and a large hepatopancreas that is formed by numerous blind-ended tubules. The precise structure and ultrastructure of these regions were presented in our previous papers, while here we focused on the ultrastructural changes that occurred in the midgut epithelial cells (D-cells in the intestine, B- and F- cells in the hepatopancreas) after long-term starvation and re-feeding. We used transmission electron microscopy, light and confocal microscopes and flow cytometry to describe all of the changes that occurred due to the stressor with special emphasis on mitochondrial alterations. A quantitative assessment of cells with depolarized mitochondria helped us to establish whether there is a relationship between starvation, re-feeding and the inactivation/activation of mitochondria. The results of our studies showed that in the freshwater shrimp N. davidi that were analyzed, long-term starvation activates the degeneration of epithelial cells at the ultrastructural level and causes an increase of cells with depolarized (non-active) mitochondria. The process of re-feeding leads to the gradual regeneration of the cytoplasm of the midgut epithelial cells; however, these changes were observed at the ultrastructural level. Additionally, re-feeding causes the regeneration of mitochondrial ultrastructure. Therefore, we can state that the increase in the number of cells with polarized mitochondria occurs slowly and does not depend on ultrastructural alterations. PMID:28282457

  9. Muscle precursor cells in the developing limbs of two isopods (Crustacea, Peracarida): an immunohistochemical study using a novel monoclonal antibody against myosin heavy chain.

    Science.gov (United States)

    Kreissl, S; Uber, A; Harzsch, S

    2008-05-01

    In the hot debate on arthropod relationships, Crustaceans and the morphology of their appendages play a pivotal role. To gain new insights into how arthropod appendages evolved, developmental biologists recently have begun to examine the expression and function of Drosophila appendage genes in Crustaceans. However, cellular aspects of Crustacean limb development such as myogenesis are poorly understood in Crustaceans so that the interpretative context in which to analyse gene functions is still fragmentary. The goal of the present project was to analyse muscle development in Crustacean appendages, and to that end, monoclonal antibodies against arthropod muscle proteins were generated. One of these antibodies recognises certain isoforms of myosin heavy chain and strongly binds to muscle precursor cells in malacostracan Crustacea. We used this antibody to study myogenesis in two isopods, Porcellio scaber and Idotea balthica (Crustacea, Malacostraca, Peracarida), by immunohistochemistry. In these animals, muscles in the limbs originate from single muscle precursor cells, which subsequently grow to form multinucleated muscle precursors. The pattern of primordial muscles in the thoracic limbs was mapped, and results compared to muscle development in other Crustaceans and in insects.

  10. Using field data to assess the effects of pesticides on crustacea in freshwater aquatic ecosystems and verifying the level of protection provided by water quality guidelines.

    Science.gov (United States)

    Guy, Martha; Singh, Lucina; Mineau, Pierre

    2011-07-01

    The purpose of this study was to investigate how well single-species laboratory data predict real-world pesticide toxicity effects on Crustacea. Data from field pesticide exposures from experimental mesocosm and small pond studies were converted into toxicity units (TUs) by dividing measured pesticide concentrations by the L(E)C50 for Daphnia or acute 5% hazard concentration for Crustacea (HC5-C). The proportion of crustacean taxa significantly affected by the pesticide treatment, called the count ratio of effect, was used in logistic regression models. Of 200 possible logistic model combinations of the TUs, fate, physicochemical variables, and structural variables versus the count ratio of effect for the mesocosm data, the best model was found to incorporate log(TU HC5-C). This model was used to convert pesticide water quality guidelines from around the world into estimates of the proportion of crustacean taxa predicted to be impacted by exposure to a pesticide at the water quality guideline concentration. This analysis suggests 64% of long-term water quality guidelines and 88% of short-term pesticide water quality guidelines are not protective of the aquatic life they are designed to protect. We conclude that empirically derived data from mesocosm studies should be incorporated into water quality guideline derivation for pesticides where available. Also, interspecific differences in susceptibility should be accounted for more accurately to ensure water quality guidelines are adequately protective against the adverse effects of pesticide exposure. Copyright © 2011 SETAC.

  11. Simultaneous determination of the Cd and Zn total body burden of individual, nearly microscopic, nanoliter-volume aquatic organisms (Hyalella azteca) by rhenium-cup in-torch vaporization (ITV) sample introduction and axially viewed ICP-AES

    Energy Technology Data Exchange (ETDEWEB)

    Smith, Andrea T.; Badiei, Hamid R.; Karanassios, Vassili [University of Waterloo, Department of Chemistry, Waterloo, ON (Canada); Evans, J. Catherine [University of Waterloo, Department of Biology, Waterloo, ON (Canada)

    2004-09-01

    The Cd and Zn total body burden of individual, up to 7-day-old aquatic organisms (Hyalella aztecabenthic amphipod) with an average volume of approximately 100 nL was determined simultaneously by using rhenium-cup (Re-cup) in-torch vaporization (ITV) sample introduction and an axially viewed inductively coupled plasma atomic emission spectrometry (ICP-AES) system. The direct elemental analysis capabilities of this system (i.e., no sample digestion) reduced sample preparation time, eliminated contamination concerns from the digestion reagent and, owing to its detection limits (e.g., in the low pg range for Cd and Zn), vit enabled simultaneous determinations of Cd and Zn in individual, neonate and young juvenile specimens barely visible to the unaided eye (e.g., nearly microscopic). As for calibration, liquid standards and the standard additions method were tested. Both methods gave comparable results, thus indicating that in this case liquid standards can be employed for calibration, and in the process making use of the standard additions method unnecessary. Overall, the ITV-ICP-AES approach by-passed the time-consuming acid digestions, eliminated the potential for contamination from the digestion reagents, improved considerably the speed of acquisition of analytical information and enabled simultaneous determinations of two elements using individual biological specimens. (orig.)

  12. Grandes branquiópodos (Crustacea, Branchiopoda, Anostraca, Notostraca en la provincia de Málaga, España (año hidrológico 2012/2013

    Directory of Open Access Journals (Sweden)

    Ripoll Rodríguez, J.

    2014-03-01

    Full Text Available Large branchiopods (Crustacea, Branchiopoda, Anostraca, Notostraca from Málaga province, Spain (2012/2013 hydrological year This paper presents the occurrence of the large branchiopods detected during a survey carried out in the province of Málaga (Andalusia, southern Spain. Five species (Branchipus cortesi, Chirocephalus diaphanus, Streptocephalus torvicornis, Triops mauritanicus aggr. and Phallocryptus spinosa were recorded at 90 sampled wetlands.

  13. First inventory of the Crustacea (Decapoda, Stomatopoda) of Juan de Nova Island with ecological observations and comparison with nearby islands in the Mozambique channel (Europa, Glorieuses, Mayotte)

    Science.gov (United States)

    Poupin, J.

    2016-04-01

    Crustacea Decapoda and Stomatopoda are inventoried for the first time in Juan de Nova Island, Iles Eparses, Mozambique channel. In total, 112 species are reported: 69 crabs, 28 anomurans, 11 shrimps, 3 mantis shrimps and 1 lobster. A comparison is made with nearby islands in the Mozambique channel: Glorieuses Islands (157 species), Europa Island (178 species), and Mayotte Island (505 species). The lower species richness at Juan de Nova is explained by the small size of the island and by the difficulties to collect the crustaceans on the reef flat hardly accessible at low tide. The crustaceans are listed by main habitats from land to outer reef (2-20 m). The presence of the coconut crab (Birgus latro), an endangered species vulnerable to human predation, is confirmed.

  14. A note on the occurrence of praniza larvae of Gnathiidae (Crustacea, Isopoda on fishes from Northeast of Pará, Brazil

    Directory of Open Access Journals (Sweden)

    Daniel G. Diniz

    2008-12-01

    Full Text Available The infection of the estuarine teleost fishes Mugil gaimardianus Desmarest, 1831 (Mugilidae, Arius phrygiatus Valenciennes, 1839 (Ariidae, Conodon nobilis Linnaeus, 1759 (Haemulidae, Cetengraulis edentulus Cuvier, 1829 (Engraulidae, and Anableps anableps Linnaeus, 1758 (Anablepidae by praniza larvae of Gnathiidae (Crustacea, Isopoda was studied in specimens fished off the Atlantic Ocean in Northeast of Pará State, near Bragança, Brazil. The highest infection prevalence value was found in Anableps anableps (42.3% and the lowest in Conodon nobilis (9.1%. The mean intensity varied from 1 parasitein Conodon nobilis to 19.5 in Arius phrygiatus. A description of the larvae is provided. The morphology of the mouthparts is related to the blood sucking activity, and is compared with the characteristics of other gnathiidae species.Foi estudada a parasitose dos peixes estuarinos Mugil gaimardianus Desmarest, 1831 (Mugilidae, Arius phrygiatus Valenciennes, 1839 (Ariidae, Conodon nobilis Linnaeus, 1759 (Haemulidae, Cetengraulis edentulus Cuvier, 1829 (Engraulidae, e Anableps anableps Linnaeus, 1758 (Anablepidae por larvas praniza de Gnathiidae (Crustacea, Isopoda em exemplares pescados no Oceano Atlântico, no Nordeste do Pará, próximo a Bragança, Brasil. O valor mais elevado da prevalência da infecção foi observado em A. anableps (42,3% e o menor em C. nobilis (9,1%. A intensidade média da parasitose variou entre 1 parasita em C. nobilis até 19,5 em A. phrygiatus. Efetua-se a descrição da larva, verificando-se que a morfologia da armadura bucal está relacionada com a atividade sugadora de sangue, e faz-se a comparação com as características de outras espécies.

  15. Preparation and characterization of a hetero functional system of gold nanoparticles labeled with {sup 99m}Tc and conjugated to the sequence Arg-Gly-Asp for detection in vivo of angio genesis and evaluation of their toxicity in Hyalella aztec; Preparacion y caracterizacion de un sistema heterofuncional de nanoparticulas de oro marcadas con Tecnecio-99m y conjugadas a la secuencia Arg-Gly-Asp para la deteccion in vivo de angiogenesis y la evaluacion de su toxicidad en Hyalella azteca

    Energy Technology Data Exchange (ETDEWEB)

    Morales A, E.

    2012-07-01

    spectroscopy techniques demonstrated that AuNP were functionalized with peptides. Rp was 96 {+-} 2% without post-labeling purification. {sup 99m}Tc-HYNIC-G GC-AuNP-RGD showed specific recognition for {alpha}{sub v}{beta}{sub 3} integrin s expressed in C6 cells, and 3 h after i.p. administration in mice, the tumor uptake was 8.18 {+-} 0.57% Id/g. Micro-SPECT/CT images showed evident tumor uptake. {sup 99m}Tc-HYNIC-G GC-AuNP-RGD demonstrates properties suitable for use as a new target-specific agent for molecular imaging of tumor {alpha}{sub v}{beta}{sub 3} expression. the second aim of this research was to determine the eco toxicological risk, measured by oxidative stress induction in Hyalella aztec, of the well-characterized multifunctional RGD-AuNP system (Tc-HYNIC-G GC-AuNP-c[RGDfK(C)]). In acute toxicological studies, a median lethal concentration of 1.83 cm{sup 2} per milliliter of medium was established for the Tc-HYNIC-G GC-AuNP-c[RGDfK(C)] conjugate. Tests assessing the effects of oxidative stress such as lipo peroxidation and protein carbonyl protein content suggest that this nano conjugate does not induces changes in oxidative markers because the activity of antioxidant defenses including catalase, glutathione peroxidase and superoxide dismutase do not show an increase related to oxidative stress imbalance. Due to the chain length and steric effect of the peptides attached to gold nanoparticles by Au-S bonds, the Tc-HYNIC-G GC-AuNP-C[RGDfK(C)] complex does not react with intracellular glutathione or thiol-proteins and, therefore, does not induce increases in reactive oxygen species. Therefore, Tc-HYNIC-G GC-AuNP-c[RGDfK(C)] (20 nm) is a new chemically stable diagnostic pharmaceutical that does not induce eco toxicity measured by the oxidative stress induction in Hyalella aztec after complete radionuclide decay. This study suggests that Hyalella aztec is a suitable model animal for environmental toxicology studies of nanoparticles. (Author)

  16. Brain architecture of the largest living land arthropod, the Giant Robber Crab Birgus latro (Crustacea, Anomura, Coenobitidae: evidence for a prominent central olfactory pathway?

    Directory of Open Access Journals (Sweden)

    Krieger Jakob

    2010-09-01

    Full Text Available Abstract Background Several lineages within the Crustacea conquered land independently during evolution, thereby requiring physiological adaptations for a semi-terrestrial or even a fully terrestrial lifestyle. Birgus latro Linnaeus, 1767, the giant robber crab or coconut crab (Anomura, Coenobitidae, is the largest land-living arthropod and inhabits Indo-Pacific islands such as Christmas Island. B. latro has served as a model in numerous studies of physiological aspects related to the conquest of land by crustaceans. From an olfactory point of view, a transition from sea to land means that molecules need to be detected in gas phase instead of in water solution. Previous studies have provided physiological evidence that terrestrial hermit crabs (Coenobitidae such as B. latro have a sensitive and well differentiated sense of smell. Here we analyze the brain, in particular the olfactory processing areas of B. latro, by morphological analysis followed by 3 D reconstruction and immunocytochemical studies of synaptic proteins and a neuropeptide. Results The primary and secondary olfactory centers dominate the brain of B. latro and together account for ca. 40% of the neuropil volume in its brain. The paired olfactory neuropils are tripartite and composed of more than 1,000 columnar olfactory glomeruli, which are radially arranged around the periphery of the olfactory neuropils. The glomeruli are innervated ca. 90,000 local interneurons and ca. 160,000 projection neurons per side. The secondary olfactory centers, the paired hemiellipsoid neuropils, are targeted by the axons of these olfactory projection neurons. The projection neuron axonal branches make contact to ca. 250.000 interneurons (per side associated with the hemiellipsoid neuropils. The hemiellipsoid body neuropil is organized into parallel neuropil lamellae, a design that is quite unusual for decapod crustaceans. The architecture of the optic neuropils and areas associated with antenna two

  17. The complete mitochondrial genome of the mantid shrimp Oratosquilla oratoria (Crustacea: Malacostraca: Stomatopoda): Novel non-coding regions features and phylogenetic implications of the Stomatopoda.

    Science.gov (United States)

    Liu, Yuan; Cui, Zhaoxia

    2010-09-01

    The complete mitochondrial (mt) genome sequence of Oratosquilla oratoria (Crustacea: Malacostraca: Stomatopoda) was determined; a circular molecule of 15,783 bp in length. The gene content and arrangement are consistent with the pancrustacean ground pattern. The mt control region of O. oratoria is characterized by no GA-block near the 3' end and different position of [TA(A)]n-blocks compared with other reported Stomatopoda species. The sequence of the second hairpin structure is relative conserved which suggests this region may be a synapomorphic character for the Stomatopoda. In addition, a relative large intergenic spacer (101 bp) with higher A+T content than that in control region was identified between the tRNA(Glu) and tRNA(Phe) genes. Phylogenetic analyses based on the current dataset of complete mt genomes strongly support the Stomatopoda is closely related to Euphausiacea. They in turn cluster with Penaeoidea and Caridea clades while other decapods form a separate group, which rejects the monophyly of Decapoda. This challenges the suitability of Stomatopoda as an outgroup of Decapoda in phylogenetic analyses. The basal position of Stomatopoda within Eumalacostraca according to the morphological characters is also questioned.

  18. On the presence of the Mediterranean endemic Microdeutopus sporadhi Myers, 1969 (Crustacea: Amphipoda: Aoridae in the Gulf of Naples (Italy with a review on its distribution and ecology

    Directory of Open Access Journals (Sweden)

    M. B. SCIPIONE

    2013-10-01

    Full Text Available The species Microdeutopus sporadhi (Crustacea: Amphipoda: Aoridae, endemic of the Mediterranean Sea, was described by Myers in 1969 on material collected from the Aegean Sea in a sheltered environment with high sedimentation rates. A check on the distribution and ecology of M. sporadhi showed that: — although not mentioned in the checklist of amphipods of the Italian seas, it was already found in the central Tyrrhenian Sea in 1983-84 and in the northern Adriatic Sea in 2002-03; — it was rarely found in the Mediterranean Sea, one of the most studied basins as concerns amphipod fauna; but notwithstanding the few records available, the wide ecological spectrum of this species was pointed out. The present study, conducted off the Island of Ischia (Gulf of Naples, Italy, showed the presence of rich and well established populations through time, but only in a peculiar substratum (artificial collectors and environment (low pH values. The species seems to be able to withstand harsh environmental conditions and probably to conceal itself through a cryptic behaviour, escaping traditional sampling methods. The role of rare or hidden species in bio-assessment should be re-evaluated.

  19. On the presence of the Mediterranean endemic Microdeutopus sporadhi Myers, 1969 (Crustacea: Amphipoda: Aoridae in the Gulf of Naples (Italy with a review on its distribution and ecology

    Directory of Open Access Journals (Sweden)

    M. B. SCIPIONE

    2013-07-01

    Full Text Available The species Microdeutopus sporadhi (Crustacea: Amphipoda: Aoridae, endemic of the Mediterranean Sea, was described by Myers in 1969 on material collected from the Aegean Sea in a sheltered environment with high sedimentation rates. A check on the distribution and ecology of M. sporadhi showed that: — although not mentioned in the checklist of amphipods of the Italian seas, it was already found in the central Tyrrhenian Sea in 1983-84 and in the northern Adriatic Sea in 2002-03; — it was rarely found in the Mediterranean Sea, one of the most studied basins as concerns amphipod fauna; but notwithstanding the few records available, the wide ecological spectrum of this species was pointed out. The present study, conducted off the Island of Ischia (Gulf of Naples, Italy, showed the presence of rich and well established populations through time, but only in a peculiar substratum (artificial collectors and environment (low pH values. The species seems to be able to withstand harsh environmental conditions and probably to conceal itself through a cryptic behaviour, escaping traditional sampling methods. The role of rare or hidden species in bio-assessment should be re-evaluated.

  20. The water flea Daphnia magna (Crustacea, Cladocera) as a test species for screening and evaluation of chemicals with endocrine disrupting effects on crustaceans.

    Science.gov (United States)

    Tatarazako, Norihisa; Oda, Shigeto

    2007-02-01

    The water flea Daphnia magna (Crustacea, Cladocera) is a cyclical parthenogen, which can reproduce both by parthenogenesis and by sexual reproduction. With its ease of handling in the laboratory, several testing methods using D. magna exist for regulatory toxicity testing. Recently, several studies revealed that one of the major hormone groups in insects and crustaceans, juvenile hormones, are involved in the shift of reproductive mode from parthenogenesis to sexual reproduction (production of male neonates). Using offspring sex ratio as a new endpoint has made it possible to identify chemicals with juvenile hormone-like effects on crustaceans. The testing method using D. magna, in which offspring sex ratio is incorporated as a new endpoint, is now being proposed to the OECD as an enhanced version of the existing OECD Test Guideline 211: Daphnia magna reproduction test. No other clear-cut endpoint for identifying juvenile-hormone disrupting effects has ever been found in crustaceans than the induction of male neonates production in cladocerans. In this regard, it is expected that testing methods using D. magna are suitable for screening and risk assessment of chemicals with juvenile-hormone disrupting effects.

  1. Seasonal fluctuations of some biological traits of the invader Caprella scaura (Crustacea: Amphipoda: Caprellidae in the Mar Piccolo of Taranto (Ionian Sea, southern Italy

    Directory of Open Access Journals (Sweden)

    Ermelinda Prato

    2013-03-01

    Full Text Available Caprella scaura is an epifaunal amphipod crustacean that originates in the western Indian Ocean and has spread throughout the world, but very little is known about fundamental aspects of its biology. This paper is the first presentation of its life history traits in an invaded region. The study was conducted in the Mar Piccolo basin (southern Italy, Ionian Sea, over a one-year period. All biological parameters showed a strong seasonal pattern, breeding peaked twice during the year and the number of eggs in the ventral brood pouch ranged from 5 to 72. The sex ratio was generally close to 1:1. A strong correlation between total length of ovigerous females and number of eggs was observed. The mean length of both mature males and mature females was 10.63 and 7.70 mm, respectively. The results of this study showed that the population dynamics of this species was not dissimilar to that of other caprellids or marine epifaunal Crustacea. This caprellid has given rise to a stable population in the Mar Piccolo; it was present all year round in the study area but its density suggests that it is not yet a strong invader.

  2. Five species of the family Cyproideidae (Crustacea: Amphipoda) from Japan, with the description of a new genus and two new species.

    Science.gov (United States)

    Ariyama, Hiroyuki

    2016-03-31

    Five species of the family Cyproideidae (Crustacea: Amphipoda) are described from shallow sea in Japan. Cyproidea liodactyla Hirayama, 1978 was collected from Kanagawa and Shizuoka Prefectures and Ariake Sea. Morphological character of the antenna 1 in these specimens is different from the original description. Examining the paratypes of C. liodactyla, the shape of the antenna 1 in the holotype is revealed to be abnormal. Cyproidea okinawensis sp. nov. was collected from Okinawa Island. Its morphological characters resemble C. liodactyla and C. robusta Ren, 2006; however, this new species is different from the former in the smaller eyes, the narrower coxa 5 and the coloration, and from the latter in the ovoid telson. Metacyproidea gen. nov. is established with M. makie sp. nov. from Hachijo Island in Tokyo Prefecture as its type species. This new genus resembles Cyproidea, especially in the peduncular article 2 of antenna 1 with a distinct distal tooth and the posterodorsal end of urosomites with a strong projection. However, Metacyproidea can be distinguished from Cyproidea by the coalesced urosomites 2-3 and the antenna 1 with a 10-16-articulated flagellum. Moolapheonoides acutifalcatus Kobayashi & Ishimaru, 2005 and Terepeltopes dolichorhunia Hirayama, 1983 were also collected from Wakayama and Fukui Prefectures and Kanagawa, Shizuoka and Yamaguchi Prefectures, respectively. A key to species of the family Cyproideidae in Japan is provided.

  3. Effect of ingested tungsten oxide (WOx) nanofibers on digestive gland tissue of Porcellio scaber (Isopoda, Crustacea): fourier transform infrared (FTIR) imaging.

    Science.gov (United States)

    Novak, Sara; Drobne, Damjana; Vaccari, Lisa; Kiskinova, Maya; Ferraris, Paolo; Birarda, Giovanni; Remškar, Maja; Hočevar, Matej

    2013-10-01

    Tungsten nanofibers are recognized as biologically potent. We study deviations in molecular composition between normal and digestive gland tissue of WOx nanofibers (nano-WOx) fed invertebrate Porcellio scaber (Iosopda, Crustacea) and revealed mechanisms of nano-WOx effect in vivo. Fourier Transform Infrared (FTIR) imaging performed on digestive gland epithelium was supplemented by toxicity and cytotoxicity analyses as well as scanning electron microscopy (SEM) of the surface of the epithelium. The difference in the spectra of the Nano-WOx treated and control cells showed up in the central region of the cells and were related to lipid peroxidation, and structural changes of nucleic acids. The conventional toxicity parameters failed to show toxic effects of nano-WOx, whereas the cytotoxicity biomarkers and SEM investigation of digestive gland epithelium indicated sporadic effects of nanofibers. Since toxicological and cytological measurements did not highlight severe effects, the biochemical alterations evidenced by FTIR imaging have been explained as the result of cell protection (acclimation) mechanisms to unfavorable conditions and indication of a nonhomeostatic state, which can lead to toxic effects.

  4. Stomatopod Crustacea of Suriname

    NARCIS (Netherlands)

    Holthuis, L.B.

    1959-01-01

    The present report is based in the first place on material collected by the trawler “Coquette”, which, from April to August 1957, explored the offshore waters of Suriname and French Guiana from the mouth of the Nickerie River in the west to the Iles de Salut in the east. Most of the hauls were made

  5. (Crustacea) from Verlorenvlei

    African Journals Online (AJOL)

    1994-08-29

    Aug 29, 1994 ... history of the system has been initiated, in order to reveal the climatic, floristic .... pinata is a benthic species, devoid of all swimming powers. The population in ..... permanent freshwater pools and dams in the Eastern Cape.

  6. Stomatopod Crustacea of Suriname

    NARCIS (Netherlands)

    Holthuis, L.B.

    1959-01-01

    The present report is based in the first place on material collected by the trawler “Coquette”, which, from April to August 1957, explored the offshore waters of Suriname and French Guiana from the mouth of the Nickerie River in the west to the Iles de Salut in the east. Most of the hauls were made

  7. Gut bacterial community structure (Porcellio scaber, Isopoda, Crustacea) as a measure of community level response to long-term and short-term metal pollution.

    Science.gov (United States)

    Lapanje, Ales; Rupnik, Maja; Drobne, Damjana

    2007-04-01

    Prokaryotes are of high importance in the assessment of environmental pollution effects. Due to fast responsiveness of bacterial communities to environmental physicochemical factors, it is difficult to compare results of bacterial community investigations on the temporal and spatial scale. To reduce the effects of variable physicochemical environmental conditions on bacterial microbiota when investigating the specific impact of contaminants on bacterial communities, we investigated the bacterial community in the gut of terrestrial isopods (Porcellio scaber, Isopoda, Crustacea) from clean and metal-polluted environments. Animals were collected from a chronically mercury-polluted site, a chronically multiple metal-(Cd, Pb, Zn) polluted site, and two reference sites. In addition, animals from an unpolluted site were laboratory exposed to 5 microg Hg/g food in order to compare the effect of acute and chronic Hg exposure. The bacterial gut microbiota was investigated by temporal temperature gradient gel electrophoresis (TTGE) and clone library construction based on polymerase chain reaction amplified 16S rRNA genes. The major bacterial representatives of the emptied gut microbiota in the animals from the chronically polluted environments seemed not affected when analyzed by TTGE. The detailed bacterial community structure investigated by 16S rRNA clone library construction, however, showed that the community from the Hg-polluted site also was affected severely (242.4 operational taxonomic units [OTU] in the polluted and 650.6 OTU in the unpolluted environment). When animals were acutely exposed to mercury, changes of bacterial community structures already were seen on TTGE profiles and no additional analysis was needed. We suggest the use of P. scaber gut bacterial community structure as a measure of effects caused by both long- and short-term exposure to pollution.

  8. Alona iheringula Sinev & Kotov, 2004 (Crustacea, Anomopoda, Chydoridae, Aloninae: life cycle and DNA barcode with implications for the taxonomy of the Aloninae subfamily.

    Directory of Open Access Journals (Sweden)

    Erika dos Santos Silva

    Full Text Available Knowledge of reproductive rates and life cycle of the Cladocera species is essential for population dynamic studies, secondary production and food webs, as well as the management and preservation of aquatic ecosystems. The present study aimed to understand the life cycle and growth of Alona iheringula Kotov & Sinev, 2004 (Crustacea, Anomopoda, Chydoridae, a Neotropical species, as well as its DNA barcoding, providing new information on the Aloninae taxonomy. The specimens were collected in the dammed portion of the Cabo Verde River (21°26'05″ S and 46°10'57″ W, in the Furnas Reservoir, Minas Gerais State, Brazil. Forty neonates were observed individually two or three times a day under controlled temperature (25±1°C, photoperiod (12 h light/12 h dark and feeding (Pseudokirchneriella subcapitata at a concentration of 105 cells.mL-1 and a mixed suspension of yeast and fish feed in equal proportion. Individual body growth was measured daily under optical microscope using a micrometric grid and 40× magnification. The species had a mean size of 413(±29 µm, a maximum size of 510 µm and reached maturity at 3.24(±0.69 days of age. Mean fecundity was 2 eggs per female per brood and the mean number of eggs produced per female during the entire life cycle was 47.6(±6.3 eggs per female. The embryonic development time was 1.79(±0.23 days and the maximum longevity was 54 days. The species had eight instars throughout its life cycle and four instars between neonate and primipara stage. The present study using molecular data (a 461 bp smaller COI fragment demonstrated a deep divergence in the Aloninae subfamily.

  9. Latitudinal patterns in the diversity of two subgenera of the genus Daphnia O.F. Müller (Crustacea: Cladocera: Daphniidae).

    Science.gov (United States)

    Popova, Ekaterina Y; Kotov, Alexey A

    2013-11-12

    Daphnia O.F. Müller (Crustacea: Cladocera: Daphniidae) is an important model in biology. It was concluded earlier that subgenus Daphnia s.str. occurs mainly in the northern hemisphere, subgenus Daphnia (Ctenodaphnia) in the southern hemisphere, which could suggest that: (1) the subgeneric differentiation is correlated with the Laurasia-Gondwanaland subdivision and (2) D. (Ctenodaphnia) is a taxon of Gondwanian origin. Some authors even discussed mechanisms of maintaince of the "ancient subgeneric north-south split", regarding such a pattern as paradoxical. But both molecular clock calculations and fossils of both subgenera from the Jurassic/Cretaceous boundary of Mongolia compromise such ideas and suggest an earlier, Pangaean, differentiation of the subgenera.        We discuss the distribution of Daphnia worldwide based on recent literature. Our analysis covers literature data on all described and on undescribed taxa revealed by genetical methods. Distributional data were associated with five main zones: southern cold (I), southern temperate (II), tropical (III), northern temperate (IV), and northern cold (V) zone. We found no "subgeneric north-south split": the distribution of Daphnia s.str. is dissymmetric between the hemispheres (antipolar), while that of Ctenodaphnia is sub-symmetric (bipolar). We suggest that both patterns are not of Mesozoic, but of Cenozoic origin. Mesozoic differentiation of the subgenera does not contradict a recent origin of the extant species, as found in e.g. Notostraca. A superficially attractive hypothesis about a Gondwanian origin of a taxon (Daphnia (Ctenodaphnia)) therefore did not pass the test of the fossil records. In addition, we agree with the opinion that an antipolar is only a variant of a bipolar pattern, as a result of an extinction in the southern hemisphere, and that these patterns are mid-late Cenozoic instead of Mesozoic.

  10. Nervous system development in the fairy shrimp Branchinella sp. (Crustacea: Branchiopoda: Anostraca): Insights into the development and evolution of the branchiopod brain and its sensory organs.

    Science.gov (United States)

    Frase, Thomas; Richter, Stefan

    2016-11-01

    Using immunohistochemical labeling against acetylated a-tubulin and serotonin in combination with confocal laser scanning microscopy and 3D-reconstruction, we investigated the temporary freshwater pond inhabitant Branchinella sp. (Crustacea: Branchiopoda: Anostraca) for the first time to provide detailed data on the development of the anostracan nervous system. Protocerebral sense organs such as the nauplius eye and frontal filament organs are present as early as the hatching stage L0. In the postnaupliar region, two terminal pioneer neurons grow from posterior to anterior to connect the mandibular neuromeres. The first protocerebral neuropil to emerge is not part of the central complex but represents the median neuropil, and begins to develop from L0+ onwards. In stage L3, the first evidence of developing compound eyes is visible. This is followed by the formation of the visual neuropils and the neuropils of the central complex in the protocerebrum. From the deutocerebral lobes, the projecting neuron tract proceeds to both sides of the lateral protocerebrum, forming a chiasma just behind the central body. In the postnaupliar region, the peripheral nervous system, commissures and connectives develop along an anterior-posterior gradient after the fasciculation of the terminal pioneer neurons with the mandibular neuromere. The peripheral nervous system in the thoracic segments consists of two longitudinal neurite bundles on each side which connect the intersegmental nerves, together with the ventral nervous system forming an orthogon-like network. Here, we discuss, among other things, the evidence of a fourth nauplius eye nerve and decussating projecting neuron tract found in Branchinella sp., and provide arguments to support our view that the crustacean frontal filament (organ) and onychophoran primary antenna are homologous. J. Morphol. 277:1423-1446, 2016. © 2016 Wiley Periodicals, Inc.

  11. Single and combined effects of cadmium and arsenate in Gammarus pulex (Crustacea, Amphipoda): Understanding the links between physiological and behavioural responses

    Energy Technology Data Exchange (ETDEWEB)

    Vellinger, Céline, E-mail: celine.vellinger@gmail.com [Laboratoire Interdisciplinaire des Environnements Continentaux (LIEC), CNRS UMR 7360, Université de Lorraine – Metz (France); Gismondi, Eric, E-mail: gismondi.eric@gmail.com [Laboratoire d’Ecologie animale et d’Ecotoxicologie, Institut de Chimie, Université de Liège, Allée du 6 Août 15, B-4000 Sart-Tilman, Liège (Belgium); Felten, Vincent, E-mail: vincent.felten@univ-lorraine.fr [Laboratoire Interdisciplinaire des Environnements Continentaux (LIEC), CNRS UMR 7360, Université de Lorraine – Metz (France); Rousselle, Philippe, E-mail: rousselle@univ-lorraine.fr [Laboratoire Interdisciplinaire des Environnements Continentaux (LIEC), CNRS UMR 7360, Université de Lorraine – Metz (France); Mehennaoui, Kahina, E-mail: meh_kahina@yahoo.fr [Laboratoire Interdisciplinaire des Environnements Continentaux (LIEC), CNRS UMR 7360, Université de Lorraine – Metz (France); Parant, Marc, E-mail: parant@univ-lorraine.fr [Laboratoire Interdisciplinaire des Environnements Continentaux (LIEC), CNRS UMR 7360, Université de Lorraine – Metz (France); Usseglio-Polatera, Philippe, E-mail: usseglio-polatera@univ-lorraine.fr [Laboratoire Interdisciplinaire des Environnements Continentaux (LIEC), CNRS UMR 7360, Université de Lorraine – Metz (France)

    2013-09-15

    Highlights: •Linking physiological to behavioural responses of G. pulex exposed to AsV and/or Cd. •AsV and/or Cd exposure exhibited similar biomarkers responses. •Contamination increases the mobilization of detoxification systems in gammarids. •Both changes in energy reserve use and allocation are involved in gammarid response. •Increased lipid peroxidation could be the cause of increasing gammarid mortality. -- Abstract: This study aimed at investigating the individual and interactive effects of cadmium (Cd) and arsenate (AsV) in Gammarus pulex (Crustacea, Amphipoda) through the use of several biomarkers. Individuals were exposed for 240 h to two concentrations of AsV or Cd alone, and all the possible binary mixtures of these concentrations of AsV and Cd in a complete factorial design. The pattern of the biomarkers’ responses to Cd and AsV alone or in mixture was similar in Gammarus pulex, even if the response intensity varied depending on the tested conditions. G. pulex responded to contamination with increased mobilization of the detoxification systems [i.e. γ-glutamyl-cystein ligase activity (GCL), reduced glutathione content (GSH) and metallothionein concentrations (MT)]. This response seems to imply changes in energy reserve utilization (total lipids and proteins are used prior to glycogen reserves), but also a possible energy reallocation from locomotion to detoxification processes. The observed increase in lipid peroxidation could be relied to the increasing gammarid mortality, despite the higher mobilization of detoxification systems. Even if the outcome of the complex interactions between AsV and Cd remains difficult to unravel, such studies are critically important for better assessing the effects of stressors on organisms, populations and communities in a multi-contamination context of ecosystems.

  12. Influência da Serra do Mar na distribuição e biologia de Aeglidae (Crustacea, Anomura) na porção leste do Estado do Paraná

    OpenAIRE

    2013-01-01

    Resumo: Um estudo sobre os padrões de distribuição dos eglídeos (Crustacea, Anomura, Aeglidae) com ocorrência no Estado do Paraná e a variação intraespecífica morfológica de Aegla schmitti dentre populações isoladas pelo conjunto de montanhas da Serra do Mar foi realizado. A análise do padrão de distribuição foi realizado principalmente com base em visitas à coleções científicas, porém coletas adicionais foram realizadas, especialmente nas bacias hidrográficas dos rios Iguaçu, Ribeira do Igua...

  13. Evaluation of toxicity to the amphipod, Hyalella azteca, and to the midge, Chironomus dilutus; and bioaccumulation by the oligochaete, Lumbriculus variegatus, with exposure to PCB-contaminated sediments from Anniston, Alabama

    Science.gov (United States)

    Ingersoll, Christopher G.; Steevens, Jeffery A.; MacDonald, Donald D.; Brumbaugh, William G.; Coady, Matthew R.; Farrar, J. Daniel; Lotufo, Guilherme R.; Kemble, Nile E.; Kunz, James L.; Stanley, Jacob K.; Sinclair, Jesse A.; Ingersoll, Christopher G.; Steevens, Jeffery A.; MacDonald, Donald D.

    2014-01-01

    The U.S. Environmental Protection Agency (USEPA) requested that as part of the remedial investigation for the Anniston, Alabama Polychlorinated Biphenyl (PCB) Site (Anniston PCB Site), that Pharmacia Corporation and Solutia Inc. (P/S) perform long-term reproduction toxicity tests with the amphipod, Hyalella azteca, and the midge, Chironomus dilutus, and bioaccumulation tests with the oligochaete, Lumbriculus variegatus, using sediment samples collected from reference locations and from Operable Unit 4 of the Anniston PCB Site. The sediment toxicity testing and sediment bioaccumulation results will be used by ARCADIS U.S., Inc. (ARCADIS) as part of a weight-of-evidence assessment to evaluate risks and establish sediment remediation goals for contaminants to sediment-dwelling organisms inhabiting the Anniston PCB Site. The goal of this study was to characterize relations between sediment chemistry and sediment toxicity and relations between sediment chemistry and sediment bioaccumulation in samples of sediments collected from the Anniston PCB Site. A total of 32 samples were evaluated from six test sites and one reference site to provide a wide range in concentrations of chemicals of potential concern (COPCs) including PCBs in samples of whole sediment. The goal of this study was not to determine the extent of sediment contamination across the Anniston PCB Site. Hence, the test sites or samples collected from within a test site were not selected to represent the spatial extent of sediment contamination across the Anniston PCB Site. Sediment chemistry, pore-water chemistry, and sediment toxicity data were generated for 26 sediment samples from the Anniston PCB Site. All of the samples were evaluated to determine if they qualified as reference sediment samples. Those samples that met the chemical selection criteria and biological selection criteria were identified as reference samples and used to develop the reference envelope for each toxicity test endpoint. Physical

  14. Padrão de deslocamento do camarão marinho Litopenaeus vannamei (Boone (Crustacea, Decapoda, Penaeidae nas fases clara e escura ao longo de 24 horas Displacement pattern of marine shrimp Litopenaeus vannamei (Boone, 1931 (Crustacea, Decapoda, Penaeidae in light and dark phases during a 24-hour period

    Directory of Open Access Journals (Sweden)

    Cibele S. Pontes

    2006-03-01

    Full Text Available O padrão diário de atividade de Litopenaeus vannamei (Boone, 1931 (Crustacea, Decapoda, Penaeidae é ainda pouco entendido. Com o objetivo de fornecer subsídios para otimizar o manejo nas fazendas de cultivo através do estudo do comportamento deste animal, foram desenvolvidos experimentos com juvenis (7,57 ± 1,01 g, mantidos em aquários (30 l. Para registro da atividade, os aquários foram submetidos a fotoperíodo artificial (fase do claro e do escuro, 12h:12 h, sendo monitorados 16 camarões (33 m² em cada fase, durante 20 dias, em janelas de 15 min a cada hora. A alimentação foi fornecida em horários aleatórios, sendo registrados os deslocamentos horizontal e vertical (focal contínuo e os comportamentos de natação e exploração (focal instantâneo. Os deslocamentos horizontal e vertical dos camarões foram mais acentuados na fase escura, predominando o comportamento de natação. A exploração do substrato ocorreu em ambas fases, acentuando-se entre cinco e sete horas após o acendimento das luzes.Litopenaeus vannamei (Boone, 1931 daily behavior pattern is still poorly understood. With the aim of optimizing the management of shrimp farms through the study of this animal behavior, experiments were performed with juvenile (7.57 ± 1.01, which were marked and kept in aquariums (30 l. To record activity, the aquariums were submitted to an artificial photoperiod (light and dark phases, 12h:12 h, with 16 shrimp (33 m² monitored in each phase for 20 days, for 15-minute periods every hour. Food was provided at random times and a record kept of horizontal and vertical displacement (continuous focal, swimming and exploration behavior (instantaneous focal. The horizontal and vertical displacements of the shrimp were greater during the dark phase, with a predominance of the swimming behavior. Exploration of the substrate occurred in both phases, with a peak between five and seven hours after the lights were turned on.

  15. Biologia e pesca do camarão sete-barbas Xiphopenaeus kroyeri (Heller (Crustacea, Penaeidae, na Armação do Itapocoroy, Penha, Santa Catarina, Brasil Fishery and Biology of the sea-bob-shrimp Xiphopenaeus kroyeri (Heller (Crustacea, Penaeidae, at Armação do Itapocoroy, Penha, Santa Catarina, Brazil

    Directory of Open Access Journals (Sweden)

    Joaquim O. Branco

    2005-12-01

    Full Text Available A pesca artesanal do camarão sete-barbas é denominada "pesca de sol a sol" e realizada em grande escala no litoral brasileiro, apresentando uma significativa importância econômica, histórica, social e cultural. Atualmente, a pesca desse camarão é considerada a de maior interesse econômico e o segundo recurso pesqueiro nas regiões Sudeste-Sul do Brasil. Com o objetivo de estudar a biologia e pesca do camarão sete-barbas na Armação do Itapocoroy, Penha (26º40'-26º47'S e 48º36'-48º38'W, durante o período de agosto de 1996 a julho de 2003 foram realizadas coletas mensais com 30 minutos de duração. Foram registrados o número e a biomassa dos exemplares por arrasto, e entre anos de 1996-1997 e 1999-2001, também foram anotados o sexo, o comprimento e peso total, estádio de maturação. Além dessas informações, entre agosto de 1998 a julho de 1999 foi analisado a dieta natural da espécie. X. kroyeri (Heller, 1862 apresentou comprimento total variando entre 3,0 e 16,0 cm e flutuações sazonais na abundância e biomassa, com as maiores taxas de captura ocorreram durante os meses de verão e outono. A relação peso/comprimento indicou um padrão de crescimento tendendo ao isométrico com tamanho de primeira maturação entre 7,3 a 7,9 cm, alcançados em seis meses de idade. A espécie apresentou dois picos de desova ao longo do ano, sendo que a pesca artesanal vem atuando com maior intensidade sobre o estoque adulto. O espectro trófico foi composto por 30 itens, sendo que os Gammaridae, areia, outros Crustacea e matéria orgânica os elementos básicos na dieta da espécie. Em média, 67,82 barcos atuam durante oito meses por ano na pesca do camarão sete-barbas na Armação do Itapocoroy, podendo capturar em torno de 170 toneladas/ano.The artisanal fishery of the sea-bob-shrimp is known as "sun to sun fishery" and is developed in large scale along the Brazilian coast, playing a significant economic, historical, social and

  16. The cavernicolous Oniscidea (Crustacea: Isopoda) of Portugal

    DEFF Research Database (Denmark)

    P. S. Reboleira, Ana Sofia; Gonçalves, Fernando J.; Oromí, Pedro

    2015-01-01

    The study of subterranean Oniscidea in Portugal has been neglected for nearly 70 years, but recent investigations have revealed high diversity. All the terrestrial isopods known from caves of mainland Portugal, including data from the literature and new material, are listed, revealing new biodive...

  17. The Caridean Crustacea of the Canary Islands

    NARCIS (Netherlands)

    Holthuis, L.B.

    1949-01-01

    The present paper is based mainly on material collected at the Canary Islands during the spring of 1947 by Dr. G. Thorson of Universitetets Zoologiske Museum at Copenhagen and Dr. C. O. van Regteren Altena of the Rijksmuseum van Natuurlijke Historie at Leiden. Most of the specimens were collected by

  18. Die Gattung Stenothoe (Crustacea, Amphipoda) im Mittelmeer

    NARCIS (Netherlands)

    Krapp-Schickel, Gertraud

    1976-01-01

    Ausgangssituation dieser Untersuchung war die Kenntnis von 11 nominellen Stenothoe-Arten im Mittelmeer. Von diesen wurde St. bosphorana Sowinski, 1898, seit der Beschreibung nicht mehr wiedergefunden, von St. dactylipotens Chevreux, 1908, kannte man nur das ♀, schließlich waren die Arten im Komplex

  19. The cavernicolous Oniscidea (Crustacea: Isopoda of Portugal

    Directory of Open Access Journals (Sweden)

    Ana Sofia P.S. Reboleira

    2015-12-01

    Full Text Available The study of subterranean Oniscidea in Portugal has been neglected for nearly 70 years, but recent investigations have revealed high diversity. All the terrestrial isopods from caves of mainland Portugal, including data from the literature and new material, are listed, revealing new biodiversity patterns. Twenty-seven species, belonging to 15 genera and six families, are known, of which 16 species are considered to be exclusively from subterranean ecosystems, i.e., troglobionts. Trichoniscidae is the most diverse family. Seven species in the family Trichoniscidae and one species in the family Styloniscidae are described as new (all with Reboleira & Taiti as authors: Trichoniscoides bellesi sp. nov. from the Montejunto Massif; T. sicoensis sp. nov. from the Sicó Massif; Metatrichoniscoides salirensis sp. nov. from the typhonic valley of Caldas da Rainha; Troglonethes olissipoensis sp. nov. from the Lisbon Peninsula; T. arrabidaensis sp. nov. from the Arrábida Massif; Miktoniscus longispina sp. nov. from the Sicó Massif and Cesaredas Plateau; Moserius inexpectatus sp. nov. from the Estremenho Massif; and Cordioniscus lusitanicus sp. nov. from Alentejo and Algarve, the southernmost provinces of Portugal. The subgenus Trogleluma Vandel, 1946 (Armadillidiidae is raised to genus level. In this geographic region terrestrial isopods are the richest group of cave-adapted animals.

  20. A transgenerational endocrine signaling pathway in Crustacea.

    Directory of Open Access Journals (Sweden)

    Gerald A LeBlanc

    Full Text Available BACKGROUND: Environmental signals to maternal organisms can result in developmental alterations in progeny. One such example is environmental sex determination in Branchiopod crustaceans. We previously demonstrated that the hormone methyl farnesoate could orchestrate environmental sex determination in the early embryo to the male phenotype. Presently, we identify a transcription factor that is activated by methyl farnesoate and explore the extent and significance of this transgenerational signaling pathway. METHODOLOGY/PRINCIPAL FINDINGS: Several candidate transcription factors were cloned from the water flea Daphnia pulex and evaluated for activation by methyl farnesoate. One of the factors evaluated, the complex of two bHLH-PAS proteins, dappuMet and SRC, activated a reporter gene in response to methyl farnesoate. Several juvenoid compounds were definitively evaluated for their ability to activate this receptor complex (methyl farnesoate receptor, MfR in vitro and stimulate male sex determination in vivo. Potency to activate the MfR correlated to potency to stimulate male sex determination of offspring (pyriproxyfen>methyl farnesoate>methoprene, kinoprene. Daphnids were exposed to concentrations of pyriproxyfen and physiologic responses determined over multiple generations. Survivial, growth, and sex of maternal organisms were not affected by pyriproxyfen exposure. Sex ratio among offspring (generation 2 were increasingly skewed in favor of males with increasing pyriproxyfen concentration; while, the number of offspring per brood was progressively reduced. Female generation 2 daphnids were reared to reproductive maturity in the absence of pyriproxyfen. Sex ratios of offspring (generation 3 were not affected in this pyriproxyfen lineage, however, the number of offspring per brood, again, was significantly reduced. CONCLUSIONS: Results reveal likely components to a hormone/receptor signaling pathway in a crustacean that orchestrates transgenerational modifications to important population metrics (sex ratios, fecundity of females. A model is provided that describes how these signaling processes can facilitate population sustainability under normal conditions or threaten sustainability when perturbed by environmental chemicals.

  1. Phylomitogenomics of Malacostraca (Arthropoda:Crustacea)

    Institute of Scientific and Technical Information of China (English)

    SHEN Xin; TIAN Mei; YAN Binlun; CHU Kahou

    2015-01-01

    Along with the sequencing technology development and continual enthusiasm of researchers on the mitochondrial genomes, the number of metazoan mitochondrial genomes reported has a tremendous growth in the past decades. Phylomitogenomics—reconstruction of phylogenetic relationships based on mitochondrial genomic data—is now possible across large animal groups. Crustaceans in the class Malacostraca display a high diversity of body forms and include large number of ecologically and commercially important species. In this study, comprehensive and systematic analyses of the phylogenetic relationships within Malacostraca were conducted based on 86 mitochondrial genomes available from GenBank. Among 86 malacostracan mitochondrial genomes, 54 species have identical major gene arrangement (excluding tRNAs) to pancrustacean ground pattern, including six species from Stomatopoda, three species from Amphipoda, two krill, seven species from Dendrobranchiata (Decapoda), and 36 species from Pleocyemata (Decapoda). However, the other 32 mitochondrial genomes reported exhibit major gene rearrangements. Phylogenies based on Bayesian analyses of nucleotide sequences of the protein-coding genes produced a robust tree with 100%posterior probability at almost all nodes. The results indicate that Amphipoda and Isopoda cluster together (Edriophthalma) (BPP=100). Phylomitogenomic analyses strong support that Euphausiacea is nested within Decapoda, and closely related to Dendrobranchiata, which is also consistent with the evidence from developmental biology. Yet the taxonomic sampling of mitochondrial genome from Malacostraca is very biased to the order Decapoda, with no complete mitochondrial genomes reported from 11 of the 16 orders. Future researches on sequencing the mitochondrial genomes from a wide variety of malacostracans are necessary to further elucidate the phylogeny of this important group of animals. With the increase in mitochondrial genomes available, phylomitogenomics will emerge as an important component in the Tree of Life researches.

  2. The cavernicolous Oniscidea (Crustacea: Isopoda) of Portugal

    DEFF Research Database (Denmark)

    P. S. Reboleira, Ana Sofia; Gonçalves, Fernando J.; Oromí, Pedro;

    2015-01-01

    The study of subterranean Oniscidea in Portugal has been neglected for nearly 70 years, but recent investigations have revealed high diversity. All the terrestrial isopods known from caves of mainland Portugal, including data from the literature and new material, are listed, revealing new biodive...... provinces of Portugal. The subgenus Trogleluma Vandel, 1946 (Armadillidiidae) is raised to genus level. In this geographic region terrestrial isopods are the richest group of cave-adapted animals....

  3. The cavernicolous Oniscidea (Crustacea: Isopoda) of Portugal

    DEFF Research Database (Denmark)

    P. S. Reboleira, Ana Sofia; Gonçalves, Fernando J.; Oromí, Pedro

    2015-01-01

    The study of subterranean Oniscidea in Portugal has been neglected for nearly 70 years, but recent investigations have revealed high diversity. All the terrestrial isopods known from caves of mainland Portugal, including data from the literature and new material, are listed, revealing new biodive...

  4. Siphonoecetini Just, 1983 (Crustacea, Amphipoda, Ischyroceridae) 10

    DEFF Research Database (Denmark)

    Just, Jean

    2012-01-01

    Two new genera and eight new species of bubocorophiid Siphonoecetini are described from north-eastern and northern Australia: Belkginoecetes bullockyensis gen. et sp. nov. B. cooee sp. nov. (type species), B. darwiniense sp. nov., B. fleurae sp. nov., B. solea sp. nov., B. springthorpei sp. nov.,...

  5. Phylogenetic systematics of the Eucarida (Crustacea malacostraca

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    Martin L. Christoffersen

    1988-01-01

    Full Text Available Ninety-four morphological characters belonging to particular ontogenetic sequences within the Eucarida were used to produce a hierarchy of 128 evolutionary novelties (73 synapomorphies and 55 homoplasies and to delimit 15 monophyletic taxa. The following combined Recent-fossil sequenced phylogenetic classification is proposed: Superorder Eucarida; Order Euphausiacea; Family Bentheuphausiidae; Family Euphausiidae; Order Amphionidacea; Order Decapoda; Suborder Penaeidea; Suborder Pleocyemata; Infraorder Stenopodidea; Infraorder Reptantia; Infraorder Procarididea, Infraorder Caridea. The position of the Amphionidacea as the sister-group of the Decapoda is corroborated, while the Reptantia are proposed to be the sister-group of the Procarididea + Caridea for the first time. The fossil groups Uncina Quenstedt, 1850, and Palaeopalaemon Whitfield, 1880, are included as incertae sedis taxa within the Reptantia, which establishes the minimum ages of all the higher taxa of Eucarida except the Procarididea and Caridea in the Upper Devonian. The fossil group "Pygocephalomorpha" Beurlen, 1930, of uncertain status as a monophyletic taxon, is provisionally considered to belong to the "stem-group" of the Reptantia. Among the more important characters hypothesized to have evolved in the stem-lineage of each eucaridan monophyletic taxon are: (1 in Eucarida, attachement of post-zoeal carapace to all thoracic somites; (2 in Euphausiacea, reduction of endopod of eighth thoracopod; (3 in Bentheuphausiidae, compound eyes vestigial, associated with abyssal life; (4 in Euphausiidae, loss of endopod of eighth thoracopod and development of specialized luminescent organs; (5 in Amphionidacea + Decapoda, ambulatory ability of thoracic exopods reduced, scaphognathite, one pair of maxillipedes, pleurobranch gill series and carapace covering gills, associated with loss of pelagic life; (6 in Amphionidacea, unique thoracic brood pouch in females formed by inflated carapace and specialized first pieopod, eclosion in zoea phase, body dorsoventrally depressed, thoracopods reduced and antennular statocyst lost, associated with planktonic life; (7 in Decapoda, double series of arthrobranchiae, laminar rostrum, acute stylocerite, two additional pairs of maxillipedes, three pairs of chelipedes and two pairs of walking legs, associated with nekto-benthonic life; (8 in Penaeidea, dendrobranchiae and post-larval mandibular palp expanded; (9 in Pleocyemata, pleopodal incubation of eggs and eclosion in zoea phase; (10 in Stenopodidea, pereiopodal exopods lost in adults and massive third chelipedes, associated with benthonic life; (11 in Reptantia + Procarididea + Caridea, pleura of second abdominal somite overlapping first and specialized setal brushes on propodus of fourth and fifth pereiopods; (12 in Reptantia, hypertrophied first chelipede, associated with benthonic life; (13 in Procarididea + Caridea, chela lost from third pereiopod and epipod-setobranch complexes for gill cleaning; (14 in Procarididea, chelae lost from first and second pereiopods; and (15 in Caridea, ocellus on ocular peduncle.

  6. On Parartemia zietziana Sayce (Crustacea Phyllopoda)

    NARCIS (Netherlands)

    Kuenen, D.J.

    1937-01-01

    On his journey to Australia, Prof. Dr. L. G. M. Baas Becking collected several specimens of Parartemia zietziana, which he kindly handed over to me for further examination. As it is a very little known species, the few details given below may add to our somewhat scanty knowledge. Sayce described thi

  7. Diversity of the Monstrilloida (Crustacea: Copepoda)

    Science.gov (United States)

    Suárez-Morales, Eduardo

    2011-01-01

    Monstrilloid copepods are protelean parasites of different groups of marine benthic invertebrates. Only their first naupliar, preadult, and adult phases are planktonic. Monstrilloids are currently represented by more than 115 nominal species contained in four genera. Its taxonomic knowledge has been hampered by nomenclatural and descriptive problems derived from their peculiar ontogeny and poor definitions of taxa. One of the most important difficulties is that of matching males to females. The only reliable methods to link the sexes of a species are the confirmation of particular apomorphies shared by both sexes, finding both sexes in the same host or as a pre-copulatory male-female pair in the plankton, or by the use of molecular markers. A general overview of the morphology of the group and its life cycle is provided herein. Recently, upgraded descriptive standards have been established and the relevance of redescribing taxa based on type and museum specimens has been demonstrated. The rate of species description per decade has had several peaks between 1840 and 2010: (1971–1980, 1991–2000, 2001–2010), each related to the activity of a few researchers. An analysis of the world distribution of published records of the Monstrilloida revealed that the Northeast Atlantic is the best studied region (45% of all records), followed by the Northwestern Atlantic (17%); the least surveyed areas include regions of the southern hemisphere (less than 3%). The Northeast Atlantic region harbors the highest number of known species (32 nominal species), followed by the Caribbean Sea/Gulf of Mexico (24), the Mediterranean/Black Sea (19), Indonesia-Malaysia-Philippines region (17), Japanese waters (17), and the Brazil-Argentina area (16). Other than these generalized patterns, little can be concluded concerning the biogeography of the group. Many species records are doubtful or improbable, and purportedly cosmopolitan nominal species are being revealed as species complexes yet to be studied. PMID:21853055

  8. Megacyllene Casey (Coleoptera, Cerambycidae): novas sinonímias e descrição de uma nova espécie

    OpenAIRE

    Monné,Miguel A.; Dilma Solange Napp

    2004-01-01

    Megacyllene ebenina sp. nov. é descrita do Brasil (Santa Catarina). Novos sinônimos propostos: M. castroi (Prosen, 1947), comb. nov., stat. nov. = M. (M.) cryptofrasciata Di Iorio, 1998 syn. nov.; M. trifasciata Viana, 1994 = M. (Sierracyllene) tafivallensis Di Iorio, 1998 syn. nov.Megacyllene Casey (Coleoptera. Cerambycidae): new synonyms and description of a new species. Megacyllene ebenina sp. nov. is described from Brazil (Santa Catarina). New synonyms: M. castroi (Prosen, 1947), comb. no...

  9. Effects of calcium, magnesium, and sodium on alleviating cadmium toxicity to Hyalella azteca

    Science.gov (United States)

    Jackson, B.P.; Lasier, P.J.; Miller, W.P.; Winger, P.V.

    2000-01-01

    Toxicity of trace metal ions to aquatic organisms, arising through either anthropogenic inputs or acidification of surface waters, continues to be both a regulatory and environmental problem. It is generally accepted that the free metal ion is the major toxic species (Florence et a1.,1992) and that inorganic or organic complexation renders the metal ion non-bioavailable (Meador, 1991, Galvez and Wood, 1997). However, water chemistry parameters such as alkalinity, hardness, dissolved organic carbon and pH influence metal ion toxicity either directly by lowering free metal ion concentration or indirectly through synergistic or antagonistic effects. Alkalinity and salinity can affect the speciation of metal ions by increasing ion-pair formation, thus decreasing free metal ion concentration. For example, Cu was found to be less toxic to rainbow trout in waters of high alkalinity (Miller and Mackay, 1980), due to formation of CuCO3 ion pair, and corresponding reduction in free Cu2+ concentration. The influence of salinity on the toxicity of cadmium to various organisms has been demonstrated in a number of studies (Bervoets et al., 1995, Hall et al., 1995, Lin and Dunson, 1993, Blust et al., 1992). In all these studies the apparent toxicity of cadmium was lowered as salinity was increased due to increased formation of CdC1+ and CDCl2 aqueous complexes that are non-toxic or of much lower toxicity than the free Cd2+ ion. Changes in pH exert both a biological and chemical effect on metal ion toxicity (Campbell and Stokes, 1985). Low pH favors greater metal ion solubility, and, in the absence of complexing ions, reduced speciation of the metal ion, which tends to increase toxicity compared to higher pH. However, Iow pH also enhances competition between H+ and metal ion for cell surface binding sites, which tends to decrease metal ion toxicity.

  10. A comparative study of different diets to optimize cultivation of Hyalella azteca in the laboratory.

    Science.gov (United States)

    Fracácio, Renata; Dias, Geisa Soares; Zagatto, Pedro Antônio; Bidinotto, Paulo Maurício; Silva, Paulo

    2011-09-01

    The aim of this study was to assess the influence of four diets on the laboratory cultivation of H. azteca, seeking to improve production of young specimens through reduced mortality and better growth and number of offspring per couple. The best diet was composed of a mixture of diluted commercial fish food, diluted yeast and primrose oil, associated with fish food flakes containing spirulina. With this diet the maximum mortality was 25 percent (at the end of 28 days), the average number of offspring/couple was 11.4 ± 2.8 (at the end of twelve days) and the peak weight and length of the males (at the end of 40 days) were 0.930 μg and 5.26 ± 1.1mm, respectively.

  11. BIOAVAILABILITY OF MERCURY IN SEDIMENTS FROM A FLOOD CONTROL RESERVOIR TO HYALELLA AZTECA

    Science.gov (United States)

    In the last three years, mercury contamination in North Mississippi flood control reservoirs has become a growing concern. Previous data indicate that three flood control reservoirs have similar total mercury sediment concentrations and that fish collected from one reservoir cont...

  12. Sediment quality assessment of Beasley Lake: Bioaccumulation and effects of pesticides in Hyalella azteca

    Science.gov (United States)

    Beasley Lake is a Conservation Evaluation Assessment Program (CEAP) watershed in the intensively cultivated Mississippi Delta, USA. Lake sediment quality at three sites was evaluated in 2004 and 2008 for biological impairment and uptake (viz. body residues) from 14 pesticides and three metabolites ...

  13. BIOAVAILABILITY OF MERCURY IN SEDIMENTS FROM A FLOOD CONTROL RESERVOIR TO HYALELLA AZTECA

    Science.gov (United States)

    In the last three years, mercury contamination in North Mississippi flood control reservoirs has become a growing concern. Previous data indicate that three flood control reservoirs have similar total mercury sediment concentrations and that fish collected from one reservoir cont...

  14. The spelling of the name Sarothrogammarus (Crustacea, Amphipoda)

    NARCIS (Netherlands)

    Stock, Jan H.

    1972-01-01

    In my recent revision of the Sarothrogammarus-group (Bijdr. Dierk., 41: 94—129, 1971), I consistently used the spelling Sarathrogammarus. Professor S. Ruffo, of Verona, kindly pointed out to me that the original spelling of the name is Sarothrogammarus (see Martynov, 1935, Trav. Inst. zool. Acad. Se

  15. Cryptic species in putative ancient asexual darwinulids (Crustacea, Ostracoda.

    Directory of Open Access Journals (Sweden)

    Isa Schön

    Full Text Available BACKGROUND: Fully asexually reproducing taxa lack outcrossing. Hence, the classic Biological Species Concept cannot be applied. METHODOLOGY/PRINCIPAL FINDINGS: We used DNA sequences from the mitochondrial COI gene and the nuclear ITS2 region to check species boundaries according to the evolutionary genetic (EG species concept in five morphospecies in the putative ancient asexual ostracod genera, Penthesilenula and Darwinula, from different continents. We applied two methods for detecting cryptic species, namely the K/θ method and the General Mixed Yule Coalescent model (GMYC. We could confirm the existence of species in all five darwinulid morphospecies and additional cryptic diversity in three morphospecies, namely in Penthesilenula brasiliensis, Darwinula stevensoni and in P. aotearoa. The number of cryptic species within one morphospecies varied between seven (P. brasiliensis, five to six (D. stevensoni and two (P. aotearoa, respectively, depending on the method used. Cryptic species mainly followed continental distributions. We also found evidence for coexistence at the local scale for Brazilian cryptic species of P. brasiliensis and P. aotearoa. Our ITS2 data confirmed that species exist in darwinulids but detected far less EG species, namely two to three cryptic species in P. brasiliensis and no cryptic species at all in the other darwinulid morphospecies. CONCLUSIONS/SIGNIFICANCE: Our results clearly demonstrate that both species and cryptic diversity can be recognized in putative ancient asexual ostracods using the EG species concept, and that COI data are more suitable than ITS2 for this purpose. The discovery of up to eight cryptic species within a single morphospecies will significantly increase estimates of biodiversity in this asexual ostracod group. Which factors, other than long-term geographic isolation, are important for speciation processes in these ancient asexuals remains to be investigated.

  16. [Euphausiids (Crustacea: Melacostraca) from the southern Mexican Caribbean Sea].

    Science.gov (United States)

    Castellanos, Iván; Gasca, Rebeca

    2002-03-01

    The composition, abundance and distribution of euphausiids from the southern part of the Mexican Caribbean Sea (August 1986) were sampled during the ARCOMM I cruise on board the R/V "Justo Sierra" of UNAM. Sampling was done using a Bongo-net (0.5 mm mesh size) performing oblique hauls from 200 m to the surface at 28 stations. Of the total euphausiid numbers, the most abundant species was Stylocheiron carinatum (49%), followed by Euphausia americana (9.8%) and E. tenera with (7.8%). The highest total density and that of the three most abundant species occurred during the night sampling, and probably was related to vertical migration patterns. The Bray-Curtis index revealed three station assemblages, related to the day-night variations of the euphausiid community. Species were distributed mainly in the oceanic area, and were absent in the neritic zones. The local fauna shows a strong affinity for the euphausiid community of the Gulf of Mexico and other areas of the Caribbean Sea. Four species are considered to be new records for the western Caribbean Sea.

  17. Use of neomysis mercedis (crustacea: mysidacea) for estuarine toxicity tests

    Energy Technology Data Exchange (ETDEWEB)

    Brandt, O.M.; Fujimura, R.W.; Finlayson, B.J. (Aquatic Toxicology Laboratory, Elk Grove, CA (United States))

    1993-03-01

    The mysid Neomysis mercedis was examined as a test organism for use in acute toxicity tests at intermediate salinities characteristic of estuarine waters. Several sensitive invertebrate species are available for marine assessments (mysids) and freshwater tests (cladocerans), but few are available for estuarine toxicity tests. Observations in the laboratory indicate that Neomysis mercedis can be reared successfully at a temperature of 17[degrees]C, a salinity of 2%, and a population density less than 5/L. Brine shrimp nauplii Artemia salina, algae, and commercial foods were used to sustain mysid cultures. Neomysis mercedis is vivaparous and can complete its life cycle in 3-4 months. Neomysis mercedis is as sensitive as or more sensitive to toxicants than the marine mysid Mysidopsis bahia and the freshwater cladocerans Daphnia magna, Ceriodaphnia dubia, and Simocephalus serrulatus. The mean 96-h LC50 values (concentrations lethal to half the test animals) for N. mercedis, in increasing order, were 0.20 [mu]g/L for thiobencarb, and for malathion, 14 [mu]g/L for carbofuran, 150 [mu]g/L for copper sulfate, 280 [mu]g/L for thiobencarb, and 1,600 [mu]g/L for molinate. Neonates (5 d postrelease) were generally more sensitive than older juveniles. Coefficients of variation (100[center dot]SD/mean) of LC50 values varied from 21 to 35%. 37 refs., 2 figs., 7 tabs.

  18. The spelling of the name Sarothrogammarus (Crustacea, Amphipoda)

    NARCIS (Netherlands)

    Stock, Jan H.

    1972-01-01

    In my recent revision of the Sarothrogammarus-group (Bijdr. Dierk., 41: 94—129, 1971), I consistently used the spelling Sarathrogammarus. Professor S. Ruffo, of Verona, kindly pointed out to me that the original spelling of the name is Sarothrogammarus (see Martynov, 1935, Trav. Inst. zool. Acad.

  19. Reproductive cycle of Macrobrachium amazonicum females (Crustacea, Palaemonidae

    Directory of Open Access Journals (Sweden)

    CMS. Sampaio

    Full Text Available Macrobrachium amazonicum is considered a favorite Brazilian species of freshwater prawn for cultivation as a result of its quick development and because it is easy to maintain in captivity. The aim of this work is to describe the sexual cycle stages and determine maturation age of the female M. amazonicum, which was collected monthly from June, 2002 to May, 2003 in the Jaguaribe River, Itaiçaba, Ceará. A monthly sample of water was also collected to determine the following parameters: temperature, dissolved oxygen, pH and salinity. A monthly sample of females was selected among the individuals caught, to determine the total weight (W T, carapace length (L C and abdomen+telson length (L A+T and to register the number of non-ovigerous females (NOF and ovigerous females (OF. Determining ovarian maturation stages of M. amazonicum was done in a laboratory by observing macroscopic characters such as coloring, size, location and appearance of ovarians examined by transparent carapace. The first maturation age was determined from the relative frequency of the total length (L T of young and adult females. The environmental parameters of the Jaguaribe River did not hold any influence in the number of individuals collected. A total of 1,337 prawns were sampled, 513 males (38.4% and 824 females (61.6%. The proportion between males and females in the studied population was of 1:1.6. Among the collected females, 492 (50.7% did not carry eggs in their abdomens (NOF and 332 (40.3% carried eggs in their abdomens (OF. There was no record of intact females. Non-ovigerous females with mature ovaries were recorded throughout all the months of collection. The female ovaries were classified as immature (IM, rudimentary (RU, intermediary (IN and mature (M. M. amazonicum females reach their first sexual maturity between 4.5 and 5.5 cm of total length.

  20. Life cycle of Cyclestheria hislopi (Baird, 1859) (Crustacea, Branchiopoda).

    Science.gov (United States)

    Yashima, M N; Baldochi, A; Rocha, O

    2011-05-01

    The Conchostraca (clam shrimps) are a group of microcrustaceans found in freshwater habitats. They inhabit the benthos, yet many can swim actively and are often associated with macrophytes. They are filter-feeders, deriving their food from suspended particles or solids stirred up from the bottom. In Brazil, five species have been recorded and the life cycle of one of these, Cyclestheria hislopi (Baird, 1859) was investigated in this study. Specimens were collected from fish-farming tanks in upstate São Paulo and from the floodplain of the Miranda River, in the Mato Grosso swamplands of center-west, Brazil. We determined the following variables: post-embryonic development, duration of life cycle (longevity), mean period between broods, duration of instars and individual growth. Taxonomic features of the Cyclestheria sp. specimens from Mato Grosso were also assessed to check the possibility that they belonged to another species of the same genus or a separate ecotype of C. hislopi.

  1. Genetic divergence of tanaidaceans (Crustacea: Peracarida with low dispersal ability

    Directory of Open Access Journals (Sweden)

    Kim Larsen

    2014-03-01

    Full Text Available In this study, the phylogeographic patterns of nuclear, ribosomal and mtDNA gene fragments of five tanaidacean species (Zeuxo, Tanaidae from the Atlantic, Pacific and Mediterranean Sea were investigated. We aimed to interpret results in the framework of current hypotheses on the distribution of small invertebrates with very limited dispersal ability. Evidence for a surprisingly high genetic divergence was found for intertidal tanaidaceans from the North Atlantic. This is a result of poor dispersal potential, as tanaidaceans have direct development, no pelagic stage, and very limited swimming capacity. However, lower genetic divergence was found between an intertidal tanaid species from the North Atlantic and two from the North Pacific, which suggests a scenario of recent colonization following the last glacial maximum. The species Zeuxo normani was found to be a species complex consisting, at least, of Z. normani (California, Z. cf. normani (Japan, Z. cf. normani (Australia, Z. sp. A (Korea, and Z. holdichi (Spain and France. Our results showed that traditional species identification underestimates tanaidacean diversity and that what have been previously perceived as reliable diagnostic morphological characters, are, however, variable and unreliable.

  2. Records of Australian Fouling Organisms: Sessile Barnacles (Crustacea, Cirripedia),

    Science.gov (United States)

    1981-04-01

    1976-April 1978. Report 731, Materials Research Labs., Melbourne. Endean, R., Kenny, R. & Stephenson, W. (1956), The ecology and distribution of...The ecology and distribution of intertidal organisms on certain islands off the Queensland coast. Aust. J. mar. Freshwat. Res. 7, 317-42. Ferguson...USA (Attention: Dr. J.R. De Palma ) Naval Oceans Systems Center, Hawaii Laboratory (Attention: Dr. J.C. Grovhoug) Dr. B.A. Foster, University of Auckland, NZ Dr. A.R. Ross, San Diego Natural History Museum, San Diego, USA

  3. Stomatopods (Crustacea: Hoplocarida from the Gulf of Tehuantepec, Mexico

    Directory of Open Access Journals (Sweden)

    I. F. Barbosa-Ledesma

    2000-06-01

    Full Text Available A total of 1173 specimens of Stomatopoda were captured in 27 localities at different depths (20 to 73 m during three oceanographic cruises in the Mexican Pacific along the continental shelf of the states of Oaxaca and Chiapas. Seven species were identified of the families Eurysquillidae, Lysiosquillidae and Squillidae. Squilla hancocki and Squilla parva were the most abundant species and the most frequently found together. The relationships between total length and carapace length were obtained for these species, which show that males of S. hancocki have a longer carapace length than females having the same total length, whereas for S. parva the opposite occurs. Larger sizes than previously reported were obtained for Lysiosquilla panamica and Squilla mantoidea. Squilla bigelowi was recorded for the first time in the Gulf of Tehuantepec. All the species were found in the intermediate platform (25-60 m; E. veleronis, S. hancocki and S. parva extended their distributions to the external platform (60-120 m, and S. hancocki and S. parva reached the circalittoral zone (10-25 m.Se capturaron un total de 1173 especímenes del orden Stomatopoda en 27 localidades a diferentes profundidades (20 a 73 m durante tres cruceros oceanográficos en el Pacífico Mexicano a lo largo de la plataforma continental de los estados de Oaxaca y Chiapas. Se identificaron siete especies de las familias Eurysquillidae, Lysiosquillidae y Squillidae. Squilla hancocki y Squilla parva fueron las especies más abundantes y las más frecuentemente encontradas juntas. Se obtuvieron las relaciones entre la longitud total y la longitud del caparazón para estas dos especies; que indican que con una misma longitud total los machos de S. hancocki tienen una longitud del caparazón mayor que las hembras, mientras que para S. parva sucede lo contrario. Se registraron longitudes totales más grandes a las reportadas previamente para Lysiosquilla panamica y Squilla mantoidea. Squilla bigelowi se registró por primera vez en el área. Todas las especies se encontraron en la plataforma intermerdia (25-60 m; E. Veleronis, S. Hancocki y S. parva se distribuyeron hasta la plataforma externa (60-120 m y S. hancocki y S. parva abarcaron la zona circalitoral (10-25 m.

  4. Redescription of five gnathiid species from Japan (Crustacea: Isopoda).

    Science.gov (United States)

    Ota, Yuzo

    2013-01-01

    Five gnathiid species from Japan are redescribed based on14 holotypes, their paratypes, topotypes, and new materials. Observations of these specimens revealed that Caecognathia kikuchii (Nunomura, 1992) should be transferred to genus Elaphognathia and Caecognathia nasuta (Nunomura, 1992) to genus Gnathia. Furthermore, Caecognathia amakusaensis Nunomura, 1992, C. saikaiensis Nunomura, 1992, Gnathia azumai Nunomura, 2012a, G. quadricephala Nunomura, 2012a, and G. recticornata Nunomura, 2012a are considered to be junior synonyms of E. kikuchii. Gnathia hirayamai Nunomura, 1992, G. nagasakiensis Nunomura, 2012a, G. shijikiensis Nunomura, 2012a, and G. brevicephala Nunomura, 2012a are considered to be junior synonyms of G. nasuta. Moreover, Gnathia sanrikuensis Nunomura, 1998 and G. mutsuensis Nunomura, 2004 are redescribed. Gnathia bungoensis Nunomura, 1982 is not completely redescribed because the key characteristics were lacking. The geographical records of these species are provided.

  5. The spelling of the name Sarothrogammarus (Crustacea, Amphipoda)

    NARCIS (Netherlands)

    Stock, Jan H.

    1972-01-01

    In my recent revision of the Sarothrogammarus-group (Bijdr. Dierk., 41: 94—129, 1971), I consistently used the spelling Sarathrogammarus. Professor S. Ruffo, of Verona, kindly pointed out to me that the original spelling of the name is Sarothrogammarus (see Martynov, 1935, Trav. Inst. zool. Acad. Se

  6. On some species of the genus Nephrops (Crustacea Decapoda)

    NARCIS (Netherlands)

    Holthuis, L.B.

    1964-01-01

    The present note is based in the first place on the Nephropsid material collected by the Australian Fisheries Steamer "Endeavour" in the waters of South and East Australia, while also the West Indian Nephrops specimens in the collections of the U.S. National Museum, Washington, D.C., and the Rijksmu

  7. Molecular effects of diethanolamine exposure on Calanus finmarchicus (Crustacea: Copepoda)

    Energy Technology Data Exchange (ETDEWEB)

    Hansen, Bjorn Henrik, E-mail: bjorn.h.hansen@sintef.no [SINTEF Materials and Chemistry, Marine Environmental Technology, Brattorkaia 17B, N-7465 Trondheim (Norway); Altin, Dag [BioTrix, N-7022 Trondheim (Norway); Booth, Andy; Vang, Siv-Hege; Frenzel, Max; Sorheim, Kristin Rist; Brakstad, Odd Gunnar [SINTEF Materials and Chemistry, Marine Environmental Technology, Brattorkaia 17B, N-7465 Trondheim (Norway); Storseth, Trond R. [SINTEF Fisheries and Aquaculture, N-7465 Trondheim (Norway)

    2010-08-15

    Alkanolamines are surface-active chemicals used in a wide range of industrial, agricultural and pharmaceutical applications and products. Of particular interest is the use of alkanolamines such as diethanolamine (DEA) in the removal of CO{sub 2} from natural gas and for CO{sub 2} capture following fossil fuel combustion. Despite this widespread use, relatively little is known about the ecotoxicological impacts of these compounds. In an attempt to assess the potential effects of alkanolamines in the marine environment, a key species in the North Atlantic, the planktonic copepod Calanus finmarchicus, was studied for molecular effects following sublethal exposure to DEA. DEA-induced alterations in transcriptome and metabolome profiling were assessed using a suppression subtractive hybridization (SSH) gene library method and high resolution magic angle spinning nuclear magnetic resonance (HR-MAS NMR), respectively. Effects were observed on transcription of genes reportedly involved in lipid metabolism, antioxidant systems, metal binding, and amino acid and protein catabolism. These effects were accompanied by altered expression of fatty acid derivates, amino acids (threonine, methionine, glutamine, arginine, alanine and leucine) and cholines (choline, phosphocholine and glycerophosphocholine). Together, SSH and HR-MAS NMR offer complementary screening tools for the assessment of molecular responses of C. finmarchicus to DEA and can be used in the study of other chemicals and organisms. Concentration-response and time-response relationships between DEA exposure and single gene transcription were investigated using quantitative PCR. Specific relationships were found between DEA exposure and the transcription of genes involved in protein catabolism (ubiquitin-specific protease-7), metal ion homeostasis (ferritin) and defence against oxidative stress ({gamma}-glutamylcysteine synthase, glutathione synthase and Cu/Zn-superoxide dismutase). At the lowest alkanolamine concentration used in these experiments, which corresponded to 0.5% of the LC{sub 50} concentration, no transcriptional effects were observed, giving information regarding the lower molecular effect level. Finally, similar transcription patterns were observed for a number of different genes following exposure to DEA, which indicates analogous mechanisms of toxicity and response.

  8. [Marine biodiversity of Costa Rica, the microcrustacea: Copepoda (Crustacea: Maxillopoda)].

    Science.gov (United States)

    Morales-Ramírez, A

    2001-12-01

    This report is part of a series that summarizes the species and localities of Costa Rican marine taxa. A review of the literature on copepods, both pelagic and benthic for the Pacific and Caribbean coast of Costa Rica, includes eighty species. Sixty seven pelagic species have been found, distributed between sixteen calanoid, one cyclopoid, three harparticoid and four poecilostomatoid families. Moreover, thirteen benthonic species distributed into six families, all harparticoids, are reported. Among the pelagic families, Pontellidae has six species, while Paracalanidae and Eucalanidae had five each. Other families, like Calanidae, Pseudodiaptomidae and Acartiidae had four species and most families only one. Forty five species are reported only for the Pacific coast, thirteen for the Caribbean coast, only nine species occurred in both coasts; being a direct consequence of the more intensive research effort in the Pacific. Pelagic copepod biodiversity reflects different oceanographic conditions in both coasts. Typical estuarine species were found in the lower region of the Gulf of Nicoya, while a mixture of estuarine and oceanic species were found in Golfo Dulce. Diversity in the Caribbean, specially at the Cahuita coral reef is lower in comparison with the copepod diversity found in other regions in the Caribbean sea. This may be due to the high sediment resuspension rate characteristic of the Cahuita coral reef, which could affect the reproduction of many holozooplankters, specially copepods. Although sixty seven pelagic copepod species appears to be in low numbers, in terms of specific biodiversity it is as high when compared to numbers found in other tropical areas. Thirteen species are reported in the literature, all harparticoids. Five species, three sub-species and one genera were new to science. Balacopsylla is reported for the first time from a neotropical regions, while the genus Karllangia, represented by two coexisting species in the Caribbean coast, belong to a few circumtropical-subtropical genera. The most diverse family was Tetragonicipitidae. This is the first effort to summarize the available information about the biodiversity of marine copepods for Costa Rica's coasts.

  9. Amphipoda (Crustacea) from Palau, Micronesia: Families Maeridae and Melitidae.

    Science.gov (United States)

    Myers, A A

    2016-09-26

    Seven species of senticaudate amphipods belonging to the families Maeridae and Melitidae are recorded from Palau, Federated States of Micronesia, and are figured. Three species are new to science and are fully described and figured.

  10. Fertilizers for Daphnia sp. (Crustacea, Cladocera) production in experimental tanks

    OpenAIRE

    Cunha, Patrícia de Souza Lima; Lanna,Eduardo Arruda Teixeira; Bastos,Rafael Kopschitz Xavier; Quadros,Moisés; Rezende,Fabrício Pereira; Freitas,Leandro Monteiro de

    2010-01-01

    The current study was aimed at investigating the use of different fertilizers - dicalcium phosphate, biosolid and quail feces - as a strategy for water fertilization in Daphnia sp production. It was used twenty-four 100-L tanks of asbestos cement distributed in a completely randomized split-plot design with six replicates, with plots in the three kinds of fertilizers (biosolid, dicalcium phosphate, and quail feces) and a control without fertilization (WF) and subplots at the times of assessme...

  11. Phylogeny of the Paracalanidae Giesbrecht, 1888 (Crustacea: Copepoda: Calanoida).

    Science.gov (United States)

    Cornils, Astrid; Blanco-Bercial, Leocadio

    2013-12-01

    The Paracalanidae are ecologically-important marine planktonic copepods that occur in the epipelagic zone in temperate and tropical waters. They are often the dominant taxon - in terms of biomass and abundance - in continental shelf regions. As primary consumers, they form a vital link in the pelagic food web between primary producers and higher trophic levels. Despite the ecological importance of the taxon, evolutionary and systematic relationships within the family remain largely unknown. A multigene phylogeny including 24 species, including representatives for all seven genera, was determined based on two nuclear genes, small-subunit (18S) ribosomal RNA and Histone 3 (H3) and one mitochondrial gene, cytochrome c oxidase subunit I (COI). The molecular phylogeny was well supported by Maximum likelihood and Bayesian inference analysis; all genera were found to be monophyletic, except for Paracalanus, which was separated into two distinct clades: the Paracalanus aculeatus group and Paracalanus parvus group. The molecular phylogeny also confirmed previous findings that Mecynocera and Calocalanus are genera of the family Paracalanidae. For comparison, a morphological phylogeny was created for 35 paracalanid species based on 54 morphological characters derived from published descriptions. The morphological phylogeny did not resolve all genera as monophyletic and bootstrap support was not strong. Molecular and morphological phylogenies were not congruent in the positioning of Bestiolina and the Paracalanus species groups, possibly due to the lack of sufficient phylogenetically-informative morphological characters. Copyright © 2013 Elsevier Inc. All rights reserved.

  12. Talitrid amphipods (Crustacea) as biomonitors for copper and zinc

    Science.gov (United States)

    Rainbow, P. S.; Moore, P. G.; Watson, D.

    1989-06-01

    Data are presented on the copper and zinc concentrations of four talitrid amphipod species (standard dry weight 10 mg), i.e. Orchestia gammarellus (Pallas), O. mediterranea Costa, Talitrus saltator Montagu and Talorchestia deshayesii (Audouin), from 31 sites in S.W. Scotland, N. Wales and S.W. England. More limited data are also presented for cadmium in O. gammarellus (three sites) and T. deshayesii (one site). In S.W. Scotland, copper concentrations were raised significantly in O. gammarellus from Whithorn and Auchencairn (Solway) and Loch Long and Holy Loch (Clyde). In S.W. England, copper concentrations were highest at Restronguet Creek, Torpoint and Gannel (Cornwall). Samples of O. gammarellus from Islay (inner Hebrides) taken adjacent to the effluent outfalls of local whisky distilleries fell into two groups based on copper concentrations (presumably derived from copper stills), the higher copper levels deriving from the more productive distilleries. High copper levels were found in T. saltator and Tal. deshayesii from Dulas Bay (Wales). Zinc levels in O. gammarellus were high in Holy Loch and Auchencairn (Scotland), Gannel and Torpoint (England) but extremely elevated (as was Zn in O. mediterranea) at Restronguet Creek. Zinc was also high in T. saltator from Dulas Bay (Wales), but not in Tal. deshayesii. Cadmium levels in O. gammarellus from Kilve (Bristol Channel) were much raised. These differences (a) conform with expectations of elevated bioavailability of these metals from well researched areas (S.W. England & N. Wales), and (b) identify hitherto unappreciated areas of enrichment in S.W. Scotland. Orchestia gammarellus is put forward as a suitable biomonitor for copper and zinc in British coastal waters.

  13. Three artotrogids (Crustacea: Copepoda: Siphonostomatoida from the Ross Sea, Antarctica

    Directory of Open Access Journals (Sweden)

    Mercedes Conradi

    2014-12-01

    Full Text Available The Artotrogidae, one of the most primitive of siphonostomatoid families, consists currently of 117 species in 21 genera. Most of these species (65% are poorly or incompletely described since they have been rarely recorded in recent decades and, when encountered, have been found in very low numbers. During the 19th Italian Antarctic Expedition, with the RV Italica, to the Ross Sea in austral summer 2004, some artotrogid copepods were collected. This paper redescribes two species of artotrogid copepods, which are known only from the Southern Ocean, Neobradypontius neglectus and Cryptopontius latus, and describes for the first time a male of the genus Neobradypontius. Furthermore, a new species is described and added to Sestropontius, increasing the number of known species of this genus to three. The main discrepancies between the original descriptions and the specimens of the two species collected from the Ross Sea redescribed here were on the armature of the antennary exopod and leg 5. The new species, Sestropontius italicae, shares with its most similar congener, S. mckinnoni, the armature of the third endopodal segment of leg 1 and leg 2 and that of the third exopodal segment of leg 4. However, the segmentation of the antennae and the armature on the antennary exopod are different.

  14. Galatheoid squat lobsters (Crustacea: Decapoda: Anomura from Korean waters

    Directory of Open Access Journals (Sweden)

    Jung Nyun Kim

    2016-10-01

    Full Text Available Abstract Ten species of Galatheoidea (squat lobsters, belonging to two families, were collected in the Korean exclusive economic zone: Galathea balssi Miyake and Baba, 1964, Galathea orientalis Stimpson, 1858, Galathea pubescens Stimpson, 1858, and Galathea rubromaculata Miyake and Baba, 1967 belonging to Galatheidae; Bathymunida brevirostris Yokoya, 1933, Cervimunida princeps Benedict, 1902, Munida caesura Macpherson and Baba, 1993, Munida japonica Stimpson, 1858, Munida pherusa Macpherson and Baba, 1993, and Paramunida scabra (Henderson, 1885 belonging to Munididae. The present study comprises the morphological description of these ten species, including drawings and color photographs, a brief review of their regional records, and a key for their identification. Although all species are common in Japanese waters, G. balssi, G. rubromaculata, B. brevirostris, C. princeps, M. caesura, and M. pherusa are new to Korean marine fauna.

  15. Fecundity and fertility of Macrobrachium amazonicum (Crustacea, Palaemonidae

    Directory of Open Access Journals (Sweden)

    R. R. da Silva

    Full Text Available In Brazil, studies with native freshwater prawn species were discontinued due to great importance of Macrobrachium rosenbergii. Therefore, it is necessary to continue investigations about our species, in order to develop technology adequate to our reality and in a future allow prawn farmers to culture other species. The aim of this study was to determine the fecundity and fertility of Macrobrachium amazonicum captured monthly from June 1999 to June 2001 from Jaguaribe River, Itaiçaba, Ceará, Brazil. Prawns were collected using fishing net and transferred at Biological Science Laboratory, Ceará State University (Fortaleza, Ceará, Brazil. Among the ovigerous M. amazonicum females, 60 were randomly selected to determine fecundity. The eggs adhered to the pleopods were taken out and they were then placed in a Gilson solution, and then stored in alcohol 70%. Individual fecundity was determined from the total egg counting, using a stereoscopic microscope. To determine fertility, ovigerous M. amazonicum females were stored in individual 10 L-glass tanks maintained under strong aeration. After the hatching, the larvae were siphoned and counted. The data referring to total length and weight of all the females, storage date, coloration and number of eggs, weight and coloration of gonad and number of hatched larvae were noted. With respect to average fecundity (F by length classes, the lowest and highest number of eggs observed was 696 and 1,554, respectively. As for fecundity by weight classes, the lowest number of eggs observed was 760 and the highest, 1,690. The highest number of eggs observed individually per hatching was 2,193. Average fecundity/total length (L and average fecundity/total weight (W may be expressed by a linear relationship. The adjusted equations are: F = -411.6 + 203.1 L (p < 0.0001 and F = 566.4 + 157.3 W (p < 0.0001, respectively. In the analysis of average fertility (N per length classes, the lowest and highest number of larvae observed was 374 and 1,301, respectively. With respect to fertility per weight classes, the lowest number of larvae was 581 and the highest, 1,391. In this work, the maximum number of larvae observed per hatching for females kept in laboratory was 2,594. Average fertility/total length and average fertility/total weight may be expressed by a linear relationship. The adjusted equations are: N = -1042.7 + 264.9 L (p < 0.0002; N = 384.1 + 160.3 W (p < 0.003. From these results we can deduced that fecundity and fertility of M. amazonicum are lower than ones commercial species, nevertheless it can be captured during all year long. The number of captured prawns was large in the months whose level of water was low; the inverse was observed in the months that the river was with a high volume of water.

  16. The Hermit Crabs (Crustacea Decapoda, Paguridea) of Northwestern North America

    NARCIS (Netherlands)

    Mclaughlin, P.A.

    1974-01-01

    A systematic study has been made of the Paguridea (exclusive of the Lithodidae) from northwestern North America. In addition to the redescriptions of all known species, two subgenera are herein raised to generic rank and a new genus is described. Several systematic problems have been resolved, and h

  17. Transformations of mercury in the terrestrial isopod Porcellio scaber (Crustacea).

    Science.gov (United States)

    Jereb, Vesna; Horvat, Milena; Drobne, Damjana; Pihlar, Boris

    2003-03-20

    The biological cycle of mercury in the terrestrial isopod Porcellio scaber was investigated. Testing the possibility of in vivo Hg(2+) methylation was divided into two methodologically different parts. Firstly, concentrations of total mercury and MeHg in isopods P. scaber and their environment from a Hg-unpolluted area were measured by the use of validated methods (CV AAS, CV AFS). The data obtained show that the percentage of MeHg in leaves, soil and faeces was less than 1%. In contrast, the percentage of MeHg in gut and hepatopancreas was increased to 14 and 77%, respectively, indicating methylation of Hg(2+) in the gut and its further accumulation in glands. To confirm this assumption, the second methodology was applied-a radiotracer technique with 203Hg(2+) of high specific activity. There are few radiotracer techniques for Hg-methylation assays; for our work we chose the method of Czuba et al. which includes alkaline leaching of Hg species, their extraction into dithizone-toluene, followed by specific separation of Hg dithizonates by thin-layer chromatography and gamma counting. All steps of the analytical protocol were checked and optimised by the use of aqueous solutions of 203Hg(2+) and Me(203)Hg(+). The most important finding was that cleaning-up the extract through a florisil column is not appropriate, because the column retains different percentages of Hg(2+) and MeHg(+) and consequently affects the accuracy of the final result. This optimised protocol was then applied to Hg transformation studies in the terrestrial isopod P. scaber. Leaching Hg species from P. scaber fed with 203Hg(2+) or Me(203)Hg(+) dosed food was completely efficient only at elevated temperatures. Preliminary results of methylation/demethlytion studies are rather variable but they show that both processes (Hg(2+)MeHg(+)) take place in the isopod P. scaber. Additionally, an assessment of the mass balance of Hg in isopods P. scaber exposed to 203Hg(2+) indicates that volatile Hg species are also formed.

  18. Species of marine Isopoda (Crustacea, Peracarida from southern Brazil

    Directory of Open Access Journals (Sweden)

    Plínio Soares Moreira

    1972-01-01

    Full Text Available Some species of marine Isopoda collected in southern Brazil mostly in shallow-water and amongst seaweeds are studied. Five species are discussed and illustrated. A diagnosis is given for each species. Idotea metallica and Synidotea marplatensis are new oc currences for the area, and both have had their geographical range extended to off Rio de Janeiro. The presence of Idotea balthica and Erichsonella filiformis in southern Brazil was definitely asserted. Illustrations of both sexes of Rocinela signata and details about its occurrence in the region surveyed were made.O presente trabalho relaciona algumas espécies de isopodes marinhos coletados na região centro-sul do Brasil, em águas razas, em algas, ou entre emaranhados de folhas e raizes. Cinco espécies são ilustradas e discutidas. Uma diagnose é dada para cada espécie. I. metallica e S. marplatensis, constituindo novas ocorrências para a região, tiveram sua distribuição geográfica consideravelmente ampliada ate o Rio de Janeiro. A presença de I. balthica e E. filiformes na região e seguramente confirmada. Finalmente, são figurados o macho e a fêmea da espécie R. signata, ao mesmo tempo em que são fornecidos detalhes sobre sua ocorrência.

  19. Remarkable convergent evolution in specialized parasitic Thecostraca (Crustacea)

    DEFF Research Database (Denmark)

    Pérez-Losada, Marcos; Høeg, Jens Thorvald; Crandall, Keith A

    2009-01-01

    the metamorphosis found in the Facetotecta and Rhizocephala suggests a common evolutionary origin, but until now no comprehensive study has looked at the basic evolution of these thecostracan groups. Results To this end, we collected DNA sequences from three nuclear genes [18S rRNA (2,305), 28S rRNA (2...

  20. An annotated bibliography of parasitic Isopoda (Crustacea of Chondrichthyes

    Directory of Open Access Journals (Sweden)

    Plínio Soares Moreira

    1978-01-01

    Full Text Available This annotated bibliography is an attempt to bring together all available published records on the parasitic isopods of Chondrichthian fishes as a basic reference source. An effort was made to synonymise old names according to the presently accepted scientific names.

  1. Global biodiversity and phylogenetic evaluation of remipedia (crustacea.

    Directory of Open Access Journals (Sweden)

    Marco T Neiber

    Full Text Available Remipedia is one of the most recently discovered classes of crustaceans, first described in 1981 from anchialine caves in the Bahamas Archipelago. The class is divided into the order Enantiopoda, represented by two fossil species, and Nectiopoda, which contains all known extant remipedes. Since their discovery, the number of nectiopodan species has increased to 24, half of which were described during the last decade. Nectiopoda exhibit a disjunct global distribution pattern, with the highest abundance and diversity in the Caribbean region, and isolated species in the Canary Islands and in Western Australia. Our review of Remipedia provides an overview of their ecological characteristics, including a detailed list of all anchialine marine caves, from which species have been recorded. We discuss alternative hypotheses of the phylogenetic position of Remipedia within Arthropoda, and present first results of an ongoing molecular-phylogenetic analysis that do not support the monophyly of several nectiopodan taxa. We believe that a taxonomic revision of Remipedia is absolutely essential, and that a comprehensive revision should include a reappraisal of the fossil record.

  2. Zoological notes from port Dickson : III. Crustacea Anomura and Brachyura

    NARCIS (Netherlands)

    Buitendijk, A.M.

    1947-01-01

    From his stay at Port Dickson on the Malay Peninsula at the beginning of 1946 Major Dr. L. D. Brongersma of the N I C A Detachment brought home several species of crabs. A list of this material which is now incorporated in the collections of the Museum of Natural History at Leiden is given below, wh

  3. Notes on adventive Amphipoda (Crustacea, Malacostraca) on the Dutch coast

    NARCIS (Netherlands)

    Stock, J.H.; Bloklander, A.E.M.H.

    1952-01-01

    During the last few years several persons have been paying attention to the animals transported by floating objects (e.g. bunches of weeds and hydroids, corks, mines, floats, etc.). A careful examination of recent finds increased the list of species known of nearly all groups of marine animals, foun

  4. Remarkable convergent evolution in specialized parasitic Thecostraca (Crustacea)

    DEFF Research Database (Denmark)

    Pérez-Losada, Marcos; Høeg, Jens Thorvald; Crandall, Keith A

    2009-01-01

    analyses indicate a convergent evolution of the very similar and highly reduced slug-shaped stages found during metamorphosis of both the Rhizocephala and the Facetotecta. This provides a remarkable case of convergent evolution and implies that the advanced endoparasitic mode of life known from...... the metamorphosis found in the Facetotecta and Rhizocephala suggests a common evolutionary origin, but until now no comprehensive study has looked at the basic evolution of these thecostracan groups. Results To this end, we collected DNA sequences from three nuclear genes [18S rRNA (2,305), 28S rRNA (2...

  5. Deep phylogeny and character evolution in thecostraca (Crustacea: Maxillopoda)

    DEFF Research Database (Denmark)

    Pérez-Losada, Marcos; Høeg, Jens Thorvald; Crandall, Keith A.

    2012-01-01

    traits associated with their lifecycle, larval biology, reproduction, and adult morphology. Our analyses show that thecostracan biological diversity resulted both from unique innovations and from events of convergence. This provides an opportunity to reevaluate previous classifications of the Thecostraca...

  6. On the origin and evolution of Antarctic Peracarida (Crustacea, Malacostraca

    Directory of Open Access Journals (Sweden)

    Angelika Brandt

    1999-12-01

    Full Text Available The early separation of Gondwana and the subsequent isolation of Antarctica caused a long evolutionary history of its fauna. Both, long environmental stability over millions of years and habitat heterogeneity, due to an abundance of sessile suspension feeders on the continental shelf, favoured evolutionary processes of preadapted taxa, like for example the Peracarida. This taxon performs brood protection and this might be one of the most important reasons why it is very successful (i.e. abundant and diverse in most terrestrial and aquatic environments, with some species even occupying deserts. The extinction of many decapod crustaceans in the Cenozoic might have allowed the Peracarida to find and use free ecological niches. Therefore the palaeogeographic, palaeoclimatologic, and palaeo-hydrographic changes since the Palaeocene (at least since about 60 Ma ago and the evolutionary success of some peracarid taxa (e.g. Amphipoda, Isopoda led to the evolution of many endemic species in the Antarctic. Based on a phylogenetic analysis of the Antarctic Tanaidacea, Sieg (1988 demonstrated that the tanaid fauna of the Antarctic is mainly represented by phylogenetically younger taxa, and data from other crustacean taxa led Sieg (1988 to conclude that the recent Antarctic crustacean fauna must be comparatively young. His arguments are scrutinized on the basis of more recent data on the phylogeny and biodiversity of crustacean taxa, namely the Ostracoda, Decapoda, Mysidacea, Cumacea, Amphipoda, and Isopoda. This analysis demonstrates that the origin of the Antarctic fauna probably has different roots: an adaptive radiation of descendants from old Gondwanian ancestors was hypothesized for the isopod families Serolidae and Arcturidae, an evolution and radiation of phylogenetically old taxa in Antarctica could also be shown for the Ostracoda and the amphipod family Iphimediidae. A recolonization via the Scotia Arc appears possible for some species, though it is not very likely (some Isopoda, like the Sphaeromatidea, are widely distributed in the Subantarctic, but rare in the high Antarctic. However, it could also be that the species of this family and others were not able to survive when the ice reached the sublittoral shelf in the high Antarctic during glacial periods.

  7. The tantulocarid genus Arcticotantalus removed from Basipodellidae into Deoterthridae (Crustacea

    DEFF Research Database (Denmark)

    Knudsen, Steen Wilhelm; Kirkegaard, Maja; Olesen, JØrgen

    2009-01-01

    is tentatively placed in Deoterthridae based on the mode of formation of the male trunk sac, the pattern of ornamentation on the tergites and cephalic shield, and the number of setae on the thoracopods and caudal rami. It is suggested that the genus Arcticotantulus Kornev, Tchesunov & Rybnikov, 2004 is removed...

  8. The Crustacea Decapoda Macrura (the Alpheidae excepted) of Easter Island

    NARCIS (Netherlands)

    Holthuis, L.B.

    1972-01-01

    So far the Crustacean fauna of Easter Island has received but very little attention. In most early narratives of expeditions visiting the island no mention is made of any Crustacean. Behrens (1908: 135) who accompanied Jacob Roggeveen on the voyage during which, in 1722, the island was discovered,

  9. A new hypogean Cyathura from New Caledonia (Crustacea, Isopoda, Anthuridea)

    NARCIS (Netherlands)

    Wägele, Johann Wolfgang

    1982-01-01

    Cyathuva numeae n.sp. from New Caledonia is the sixth blind species of the genus Cyathura Norman & Stebbing, 1886, found in hypogean habitats. The new species lives in the interstitia of coastal sand or gravel, like C. milloti Chappuis et al., 1956, from Réunion. A close relationship to the other sp

  10. Two new species of Floresorchestia (Crustacea, Amphipoda, Talitridae) in Thailand.

    Science.gov (United States)

    Wongkamhaeng, Koraon; Dumrongrojwattana, Pongrat; Pattaratumrong, Manasawan Saengsakda

    2016-01-01

    The beach-hopper and land-hopper genus Floresorchestia Bousfield, 1984 is most widespread in terrestrial and marine littoral habitats and has been recorded from the South African coasts through to tropical Indo-Pacific and Caribbean Sea. In Thailand, there is only Floresorchestia samroiyodensis Azman, Wongkamhaeng & Dumrongrojwattana, 2014 reported from the swamp of Prachuab Kiri Khan, southern Thailand. In this work, two new species of Floresorchestia from Phutsa Reservoir in Nakhon Ratchasima and the man-made swamp in Burapha University are described. The new species are characterised by the mandible left lacinia mobilis 4-dentate; the posterior margin of merus, carpus and propodus covered in palmate setae; the uropod 3 peduncle with two robust setae and the telson longer than broad. The characters of the specimens are described and illustrated in this paper. All specimens are deposited in the Princess Maha Chakri Sirindhorn Natural History Museum, Prince of Songkla University, Thailand.

  11. On some Indo-westpacific Palaemoninae (Crustacea Decapoda Caridae)

    NARCIS (Netherlands)

    Holthuis, L.B.

    1952-01-01

    Since the publication of my paper on the prawns of the subfamily Palaemoninae collected by the Siboga and Snellius Expeditions (Holthuis, 1950, Siboga Exped., mon. 39a9), I had the opportunity to examine more material of this group, which enabled me to make additions and corrections to the above pap

  12. The tantulocarid genus Arcticotantalus removed from Basipodellidae into Deoterthridae (Crustacea

    DEFF Research Database (Denmark)

    Knudsen, Steen Wilhelm; Kirkegaard, Maja; Olesen, JØrgen

    2009-01-01

    from Basipodellidae and placed in Deothertridae instead, in accordance with the mode of trunk sac development in males and the absence in the latter family of a cephalic rostrum. Various internal anatomical features were examined, including the tubular structures inside the head of the tantulus larvae....... The first live photographs of any species of Tantulocarida are presented. This is also the first report on Tantulocarida from West Greenland....

  13. A new species of Branchinecta (Crustacea: Anostraca) from Uruguay.

    Science.gov (United States)

    Rogers, D Christopher; Lorenz, Helen Racz

    2015-10-22

    Branchinecta uruguayensis, a new species of fairy shrimp, is described from a single seasonally astatic aquatic habitat in coastal Uruguay. This is the first record of an anostracan from the nation of Uruguay. Male B. uruguayensis n. sp. are separated from other Branchinecta species by the form of the second antennae. Branchinecta uruguayensis n. sp. share the distal antennomere lobiform projection with B. papillata Rogers, De los Rios, & Zúñiga, 2008 and B. achalensis César, 1985. Branchinecta uruguayensis n. sp. females are readily separated from all other Branchinecta by the presence of posteriolateral thoracic spines and lateral crenulations on the first abdomen segment margins. A key is provided to the Branchinectidae of South America.

  14. Behavioral repertory of Trichodactylus panoplus (Crustacea: Trichodactylidae under laboratory conditions

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    Bianca L. Zimmermann

    2009-03-01

    Full Text Available This work describes the behavioral repertory of Trichodactylus panoplus von Martens, 1869, based on the animals' diel activity and the possible substrate preference under laboratory experiments. Three experimental replicates were carried out, each using six animals (three males and three females. There were four periods of observation a day, with a total of 864 observation sessions and 144 hours of experiments. A total of 15 behavioral acts divided into five categories were recorded: feeding, exploration of the environment, immobility, social interaction, and self-grooming. The obtained results suggest that T. panoplus has greater activity during the night (p < 0.05, yet without showing an activity peak. In addition, the acceptance of food does not depend on the photoperiod. There was a significant preference for gravel as the chosen substrate. The Morisita index indicates an aggregated distribution of these animals, confirming their preference for substrate with gravel. The increase in activity at night and the preference for substrate with gravel, which can be used to disguise these individuals, would be associated to some anti-predator strategies of these crabs against visually orientated predators.

  15. RNA Interference with Special Reference to Combating Viruses of Crustacea

    OpenAIRE

    La Fauce, Kathy; Owens, Leigh

    2012-01-01

    RNA interference has evolved from being a nuisance biological phenomenon to a valuable research tool to determine gene function and as a therapeutic agent. Since pioneering observations regarding RNA interference were first reported in the 1990s from the nematode worm, plants and Drosophila, the RNAi phenomenon has since been reported in all eukaryotic organisms investigated from protozoans, plants, arthropods, fish and mammals. The design of RNAi therapeutics has progressed rapidly to design...

  16. Control of cardiovascular function and its evolution in Crustacea.

    Science.gov (United States)

    McMahon, B R

    2001-03-01

    Work in the last decade has shown that crustacean open circulatory systems are highly efficient and controlled in a complex manner. Control occurs at several levels. Myocardial contraction is initiated in the cardiac ganglion but constantly modulated by the central nervous system, both directly via the cardioregulatory nerves and indirectly via the neurohormonal system. Heart rate and stroke volume can be controlled independently and measurements of both are needed to assess cardiac output accurately. Haemolymph outflow from many arthropod hearts is via a complex multiarterial distribution system, and the regional distribution of cardiac output is tightly controlled via cardioarterial valves at the base of each artery. These valves contain innervated muscle, and differential contraction serves to regulate the efflux of oxygenated haemolymph into a particular system. The major influence on both the evolution and control of arthropod open blood vascular systems is efficiency of oxygen uptake and delivery. This influence is illustrated by reference to a variety of crustacean and other arthropod types.

  17. Cladocera (Crustacea: Branchiopoda of Vientiane province and municipality, Laos

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    Alexey A. Kotov

    2013-12-01

    Full Text Available We present the first faunistic report on the Laotian Cladocera from diverse habitats in Vientiane province, Central Laos. We counted a total of 70 species, belonging to 37 genera, which is realistically close to an estimated 77 species. The five most common species were Diaphanosoma excisum, Ephemeroporus cf. barroisi, Anthalona harti, Macrothrix spinosa and Chydorus cf. eurynotus. The fauna is typically Oriental/Southeast (SE Asian, showing a strong similarity with neighbouring countries and especially Thailand. We discussed the current taxonomical status of the species and provided illustrations of the main taxa for future comparison. There are no surprising faunistic elements, except for a few new records for SE Asia (Matralona freyi, Ilyocryptus thailandensis. Our data is preliminary, as the fauna of Laos remains insufficiently studied. As for SE Asia as a whole, a significant number of taxa is in need of taxonomical revision.

  18. The Species of the genus Sacculina (Crustacea Rhizocephala)

    NARCIS (Netherlands)

    Boschma, H.

    1937-01-01

    The genus Sacculina was founded by Thompson (1836), who described the species Sacculina carcini, the parasite of the shore crab. A second species, Sacculina inflata, was described by Leuckart (1859). Anderson (1862) gave a description of a third species, Sacculina triangularis, and published importa

  19. The decapod and stomatopod Crustacea of St Paul's Rocks

    NARCIS (Netherlands)

    Holthuis, L.B.

    1980-01-01

    INTRODUCTION Saint Paul's Rocks (Penedos de São Pedro e São Paulo) are a small group of rocky islets on the mid-Atlantic ridge near the equator, occupying an area of roughly 250 by 425 m. There is no vegetation and, apart from birds and invertebrates, the islands are uninhabited. The Cambridge Exped

  20. Feeding habits of Hyale media (Dana, 1853 (Crustacea-Amphipoda

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    Airton Santo Tararam

    1985-01-01

    Full Text Available Feeding of males and females of the Gammaridea Hyate media at mature and immature stages were tested in laboratory experiments. Macro and microscopic algae as well as dead or alive animals were utilized as food. This gammarid is omnivorous, feeding by predation, scavenging, browsing and scraping. Feeding behaviour was discontinuous. Padina vickersiae was more utilized in winter and Ulva fasciata in summer. The feeding activity of all the animals showed great variability in relation to the type of food. Higher temperatures probably account for the higher consumption observed in summer.

  1. Foregut morphology of Macrobrachium carcinus (Crustacea, Decapoda, Palaemonidae)

    OpenAIRE

    LIMA, J.F.; GARCIA, J. da S.; Tavares, M.

    2016-01-01

    ABSTRACT Macrobrachium carcinus is a Brazilian native prawn with recognized potential for use in aquaculture activities. The aim of this study was to describe and illustrate in detail the morphology of the M. carcinus foregut. The foregut comprises the mouth, esophagus and stomach. It is lined by a simple cylindrical epithelium overlain by chitinous cuticle. The cardiac chamber is well supplied with muscles and lined with chitin thickened in places to form a complex, articulating set of ossic...

  2. Identifying Chinese species of Gammarus (Crustacea: Amphipoda) using DNA barcoding

    Institute of Scientific and Technical Information of China (English)

    Zhong-e HOU; Zhu LI; Shu-qiang LI

    2009-01-01

    Using a standard cytochrome c oxidase I sequence, DNA barcoding has been shown to be effective to distinguish known species and to discover cryptic species. Here we assessed the efficiency of DNA barcoding for the amphipod genus Gammarus from China. The maximum intraspecific divergence for widespread species, Gammarus lacustris, was 3.5%, and mean interspecific divergence reached 21.9%. We presented a conservative benchmark for determining provisional species using maximum intraspecific divergence of Gammarus lacustris. Thirty-one species possessed distinct barcode clusters. Two species were comprised of highly divergent clades with strong neighbor-joining bootstrap values, and likely indicated the presence of cryptic species. Although DNA barcoding is effective, future identification of species of Gammarus should incorporate DNA barcoding and morphological detection[Current Zoology 55(2):158-164,2009].

  3. Effects of predation by Hydra (Cnidaria on cladocerans (Crustacea: Cladocera

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    Ligia Rivera-De la Parra

    2016-03-01

    Full Text Available Planktonic cladocerans have evolved different strategies to avoid predation from vertebrates; these include changes in morphology, behavior, physiology, and/or life-history traits. However, littoral cladocerans are better adapted to avoid invertebrate predation particularly from insect larvae by evolving morphological and physiological adaptations. Nevertheless, this has not been proven for some littoral predators such as Hydra. In this study, we provide quantitative data on how Hydra affects its zooplankton prey. We studied the predation behavior on Alona glabra, Ceridodaphnia dubia, Daphnia pulex, Daphnia cf. mendotae, Diaphanosoma birgei, Macrothrix triserialis, Moina macrocopa, Pleuroxus aduncus, Scapholeberis kingi, Simocephalus vetulus, Elaphoidella grandidieri, Brachionus rubens and Euchlanis dilatata. We also tested the indirect effect of allelochemicals from Hydra on the demography of Daphnia cf. mendotae. Littoral cladocerans are specially adapted to resist nematocyst injection and discharge of toxic substances from Hydra. A significant decrease in the population growth rate from 0.21 to 0.125 d-1 was observed at densities of 2 ind. ml-1. The role of carapace thickness as an adaptive strategy of littoral cladocerans against Hydra predation is discussed.

  4. The genus Chlamydotheca Saussure (Crustacea: Ostracoda in northeastern Argentina

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    Analía R. Díaz

    Full Text Available The genus Chlamydotheca Saussure, 1858 is a typical representative of the Neotropical ostracod fauna that occupies lotic and lentic environments including temporary and permanent ponds. Up to the present, four species have been recorded in Argentina: C. iheringi (Sars, C. incisa (Claus and C. leuckarti (Claus, and C. symmetrica (Vávra. Temporary and permanent ponds of this region were sampled for ostracods, using a fine mesh net. Three species belonging to the genus Chlamydotheca were collected of which C. arcuata (Sars is recorded for first time for the Chacoan region. Limb morphology was studied under light microscope and line drawings were made using camera lucida. Valves were photographed under scanning electron microscope and redescriptions of C. arcuata and C. iheringi are provided and distributional aspects of the species sampled are discussed.

  5. First Zoeal Stage of Camptandrium sexdentatum (Crustacea: Decapoda: Camptandriidae

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    Park, Jay Hee

    2014-10-01

    Full Text Available The first zoea of Camptandrium sexdentatum is described for the first time with a digital image of live zoeas. An ovigerous crab of C. sexdentatum was collected at the muddy sand flat in Namhaedo Island on 2 June 2012 and hatched in the laboratory on 6 June 2012. In Camptandriidae, the first zoea of C. sexdentatum is distinguished from the first zoeas of Cleistostoma dilatatum and Deiratonotus cristatum by having no dorsal and lateral carapace spines, an abdomen significantly broadened posteriorly, and a subovoid telson without forks. Especially, the finding of a subovoid telson without forks is the first report in brachyuran zoeas.

  6. COMPORTAMENTO REPRODUTIVO DE Dendrocephalus brasiliensis, Pesta 1921 (CRUSTACEA: ANOSTRACA

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    José Patrocínio Lopes

    2011-12-01

    Full Text Available The reproductive behavior of fresh water Anostracan has not been massively studied by the carcinology specialized literature, regarding especially the Dendrocephalus brasiliensis Pesta, 1921, about which there are abundant studies only on the geographical distribution of that Anostracan. The objective of this research was to investigate the reproductive behavior of this Anostracan in different periods (dry and rainy. For this, mature individuals of both sexes were used. They were collected in four ponds of the Fish Farming Station of Paulo Afonso (FFSPA, by monthly capture in each pond, within the period from December 2004 to November 2005. The reproduction type was observed by placing some females in aquariums with males and placing the other ones individually, starting from the nauplii phase, where they stayed for 15 days (reproductive age. The individuals' sexual proportion was calculated by the relative frequencies of males and of females, every month, for the whole collection period. At 10 days cysts production is possible and the number of produced cysts is related to the size of the female. The ratio male:female in the studied period was of 1 male to 1.07 female. The proportion male:female was 51.75% female to 48.25% male along the year. The observation of the reproductive behavior showed the reproduction is sexed.

  7. Review of Palaemoninae (Crustacea: Decapoda: Caridea) from Vietnam, Macrobrachium excepted

    NARCIS (Netherlands)

    Xuan, Van N.

    1992-01-01

    An account is presented of the species of Palaemoninae known from Vietnam, the genus Macrobrachium excluded. Of each species a description or descriptive notes are provided, and the habitat and economic importance are discussed. Illustrations of each species, two of which are new to science, are giv

  8. Comparative ultrastructure of the root system in rhizocephalan barnacles (Crustacea

    DEFF Research Database (Denmark)

    Bresciani, J; Høeg, Jens Thorvald

    2001-01-01

    . The rootlets consist of a cuticle, an epidermis and a subjacent layer of axial cells that often, but not always surround, a central lumen. The rootlets are at all times enclosed in a less than 0.5 microm thick cuticle, which is never molted. The cuticle consists of an inner homogeneous layer with a slightly...... by long septate junctions and exhibit the characteristics of a transporting epithelium. Experiments with acid phosphatase revealed activity both in the epidermis and among the microcuticular projections. The projections may therefore form a domain that is important in absorption and extracellular...... the rootlets towards the external reproductive body. In C. delagei the single, bladder-shaped rootlet lacks both the apical projections in the epidermis, the electron-dense cuticle layer, and the microcuticular projections. We review previous studies on the rhizocephalan root system and discuss functional...

  9. Redescription of three cirolanid isopods (Crustacea: Peracarida) from Indonesia.

    Science.gov (United States)

    Sidabalok, Conni M; Bruce, Niel L

    2016-05-24

    Three species of Cirolanidae described by Nierstrasz in 1931 are redescribed from the type material: Cirolana indica Nierstrasz, 1931, with new material from Singapore and Lombok Island, Indonesia; C. vanhoeffeni Nierstrasz, 1931; and C. stebbingi Nierstrasz, 1931, which is here transferred to the genus Politolana Bruce, 1981 based on the elongate body, long peduncle of pleopod 1, narrow and slender frontal lamina, flat and robust carpus of pereopod 7, long and acute robust setae on merus-propodus pereopod 1, secondary unguis on dactylus, and antenna peduncle articles 1-2 shorter than the subequal articles 3-5.

  10. Embriologia do siri Arenaeus cribrarius (Lamarck (Crustacea, Brachyura, Portunidae Embryology of the swimming crab Arenaeus cribrarius (Lamarck (Crustacea, Brachyura, Portunidae

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    Marcelo A.A. Pinheiro

    2002-06-01

    Full Text Available Ovigerous females of Arenaeus cribrarius were collected at Ubatuba, São Paulo, and maintaining in aquaria under controlled temperature (25±1ºC, salinity (35±1‰ and photoperiod (12:12. A small sample of eggs was collected for each 24h, for morphological description, chromatic changes and biometric analysis throughout the embryonic development. Eight egg stages were photographed and had their small and large diameters measured under a microscope provided with camera lucida. The egg's shape was low elliptical during all the embryogenesis and showed size increase (24.4% and volume (91.1 %, when the last stage were compared with the first one. According to mean egg diameter and volume, the eggs should be pooled in three different groups (1-3; 4-6; 7-8 corresponding to initial, intermediate and final stages. The attained results were compared with the literature which emphasizing the species of Portunidae's family.

  11. Shrimps from the Santana Group (Cretaceous: Albian: new species (Crustacea: Decapoda: Dendrobranchiata and new record (Crustacea: Decapoda: Caridea

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    ALLYSSON P. PINHEIRO

    2014-06-01

    Full Text Available The fossil shrimp Araripenaeus timidus n. gen. n. sp. is the first fossil Penaeoidea from Brazil. Here, we describe, illustrate and compare it with Paleomattea deliciosa, a fossil Sergestoidea (Dendrobranchiata previously described from the same region. The material of the early Cretaceous (Albian was collected in the town of Jardim, south of the state of Ceará, in the superior septarian concretion level of the Romualdo Formation. Additionally, a second specimen of Kellnerius jamacaruensis was found in the same site of the Araripe Basin.

  12. Shrimps from the Santana Group (Cretaceous: Albian): new species (Crustacea: Decapoda: Dendrobranchiata) and new record (Crustacea: Decapoda: Caridea).

    Science.gov (United States)

    Pinheiro, Allysson P; Saraiva, Antônio Áf; Santana, William

    2014-04-29

    The fossil shrimp Araripenaeus timidus n. gen. n. sp. is the first fossil Penaeoidea from Brazil. Here, we describe, illustrate and compare it with Paleomattea deliciosa, a fossil Sergestoidea (Dendrobranchiata) previously described from the same region. The material of the early Cretaceous (Albian) was collected in the town of Jardim, south of the state of Ceará, in the superior septarian concretion level of the Romualdo Formation. Additionally, a second specimen of Kellnerius jamacaruensis was found in the same site of the Araripe Basin.

  13. Morfologia setal de Parastacus brasiliensis (von Martens (Crustacea, Decapoda, Parastacidae Setae morphology of Parastacus brasiliensis (von Martens (Crustacea, Decapoda, Parastacidae

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    Ana Cristina Moura Horn

    2004-12-01

    Full Text Available A familia Parastacidae compreende os crustáceos límnicos popularmente conhecidos como lagostins da água doce. Parastacus Huxley, 1879 é o único gênero que ocorre no Brasil, e inclui, no estado do Rio Grande do Sul, a espécie endêmica, Parastacus brasiliensis (von Martens, 1869. Os espécimes foram coletados com armadilhas em um arroio nas cabeceiras da bacia do Rio Gravataí, município de Taquara, Rio Grande do Sul, Brasil. Os animais capturados foram transportados até o Laboratório de Crustáceos Universidade Federal do Rio Grande do Sul e criados em aquários até atingirem o estado adulto. Os espécimes foram dissecados e suas estruturas examinadas por microscopia óptica e desenhados em câmara clara. O material foi ainda preparado para fotografia sob exame com microscópio eletrônico de varredura. Procedeu-se à análise e classificação de todos tipos de setas encontradas nas formas adultas de P. brasilieinsis.The family Parastacidae comprises the limnic crustaceans popularly known as crayfishes or crawfishes. Parastacus Huxley, 1879 is the only genus occurring in Brazil and has an endemic species, Parastacus brasiliensis (von Martens,1869, in Rio Grande do Sul State. The individuals were collected with traps from a brook in the springs of Gravataí basin, Taquara, Rio Grande do Sul State, Brazil. The captured animals were taken to the Universidade Federal do Rio Grande do Sul Carcinology Laboratory and raised to full growth in aquaria. The specimens were dissected, and the setae analysed under optical microscopy and drawn with the aid of a camera lucida. Material was prepared for photography under scanning electron microscope. The analysis and classification of all types of setae in the adult forms of P. brasilieinsis was performed.

  14. Exoskeletal proteins from the crab, Cancer pagurus

    DEFF Research Database (Denmark)

    Andersen, Svend Olav

    1999-01-01

    Crustacea; decapods; cuticle; exoskeleton; structural protein; amino acid sequence; mass spectrometry......Crustacea; decapods; cuticle; exoskeleton; structural protein; amino acid sequence; mass spectrometry...

  15. Megacyllene Casey (Coleoptera, Cerambycidae: novas sinonímias e descrição de uma nova espécie

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    Miguel A. Monné

    2004-01-01

    Full Text Available Megacyllene ebenina sp. nov. é descrita do Brasil (Santa Catarina. Novos sinônimos propostos: M. castroi (Prosen, 1947, comb. nov., stat. nov. = M. (M. cryptofrasciata Di Iorio, 1998 syn. nov.; M. trifasciata Viana, 1994 = M. (Sierracyllene tafivallensis Di Iorio, 1998 syn. nov.Megacyllene Casey (Coleoptera. Cerambycidae: new synonyms and description of a new species. Megacyllene ebenina sp. nov. is described from Brazil (Santa Catarina. New synonyms: M. castroi (Prosen, 1947, comb. nov., stat. nov. = M. (M. cryptofrasciata Di Iorio, 1998 syn. nov.; M. trifasciata Viana, 1994 = M. (Sierracyllene tafivallensis Di Iorio, 1998 syn. nov.

  16. Interlaboratory Evaluation of Hyalella Azteca and Chironomus Tentans Short-term and Long-term Sediment Toxicity Tests

    Science.gov (United States)

    This paper presents the results of interlaboratory toxicity tests on sediment toxicity methods for use in routine testing and this data has been presented in an EPA report and this is a summary of that data.

  17. The Influence of Test Conditions on the Performance of Chironomus dilutus and Hyalella azteca in Sediment Toxicity Tests

    Science.gov (United States)

    In most all sediment toxicity assessments, the performance of organisms in control sediments is a key parameter in defining sediment toxicity, whether through direct statistical comparison to control or by normalizing to control performance to compare results across sites or batc...

  18. The acute and chronic toxicity of major geochemical ions to Hyalella azteca Ion interactions and comparisons to other species

    Science.gov (United States)

    We have previously reported that the acute and chronic toxicities of major geochemical ions (Na, K, Ca, Mg, Cl, SO4, HCO3) to Ceriodaphnia dubia can involve multiple, independent mechanisms. The toxicities of K, Mg, and Ca salts were best related to the chemical activity of the c...

  19. Responses of Hyalella azteca to a Pesticide-Nutrient Mixture in Vegetated and Non-vegetated Wetland Mesocosms

    Science.gov (United States)

    Aquatic vegetation has been shown to improve water quality by trapping and processing contaminants such as pesticides, nutrients and sediments. Currently there is little information regarding effects of pesticide and nutrient mixtures on aquatic biota in these systems and the influence aquatic vege...

  20. The acute and chronic toxicity of major geochemical ions to Hyalella azteca Ion interactions and comparisons to other species

    Science.gov (United States)

    We have previously reported that the acute and chronic toxicities of major geochemical ions (Na, K, Ca, Mg, Cl, SO4, HCO3) to Ceriodaphnia dubia can involve multiple, independent mechanisms. The toxicities of K, Mg, and Ca salts were best related to the chemical activity of the c...

  1. The Influence of Test Conditions on the Performance of Chironomus dilutus and Hyalella azteca in Sediment Toxicity Tests

    Science.gov (United States)

    In most all sediment toxicity assessments, the performance of organisms in control sediments is a key parameter in defining sediment toxicity, whether through direct statistical comparison to control or by normalizing to control performance to compare results across sites or batc...

  2. Interlaboratory Evaluation of Hyalella Azteca and Chironomus Tentans Short-term and Long-term Sediment Toxicity Tests

    Science.gov (United States)

    This paper presents the results of interlaboratory toxicity tests on sediment toxicity methods for use in routine testing and this data has been presented in an EPA report and this is a summary of that data.

  3. Crescimento do caranguejo de água doce, Dilocarcinus pagei Stimpson (Crustacea, Brachyura, Trichodactylidae Growth of the freshwater crab, Dilocarcinus pagei Stimpson (Crustacea, Brachyura, Trichodactylidae

    Directory of Open Access Journals (Sweden)

    Marcelo A. A. Pinheiro

    2005-09-01

    Full Text Available A biologia de caranguejos de água doce tem sido pouco enfocada na literatura carcinológica, especialmente em relação ao crescimento das espécies da família Trichodactylidae. Este estudo visa determinar as curvas de crescimento em tamanho e peso, bem como a longevidade e a idade na muda pubertária dos caranguejos de água doce Dilocarcinus pagei Stimpson, 1861. As amostras foram obtidas mensalmente na Represa Municipal de São José do Rio Preto (São Paulo, de outubro/1994 a setembro/1996. Os indivíduos tiveram o sexo determinado, sendo também mensurados (LC = largura do cefalotórax e pesados (PE = peso úmido. O crescimento dos indivíduos foi determinado pelo método de distribuição dos exemplares em classes de tamanho, sendo utilizado o programa FiSAT para a determinação das curvas através do ajuste não linear dos dados pelo modelo de Bertalanffy. Foram analisados 962 exemplares (534 machos e 428 fêmeas e as curvas de crescimento em tamanho foram expressas pelas equações LC Machos = 61,7[1-e-0,97(t+0,041] e LC Fêmeas = 57,1[1-e-1,41(t+0,031], enquanto o crescimento em peso foi melhor representado por PE Machos = 65,2[1-e-0,97(t+0,041]3,08 e PE Fêmeas = 44,9[1-e-1,41(t+0,031]2,82. O tamanho assintótico dos machos (61,66 mm foi pouco superior ao das fêmeas (57,09 mm, ocorrendo o inverso para a longevidade, estimada em 2,4 e 2,7 anos, respectivamente. O tamanho máximo estimado com base em 95% do tamanho assintótico foi de 58,6 mm para os machos e 54,2 mm para as fêmeas, valores muito próximos dos maiores tamanhos registrados na natureza para cada sexo (55,8 mm. A muda da puberdade dos machos ocorreu com idade superior à das fêmeas (tMachos = 1,2 anos e tFêmeas = 0,9 anos. Os resultados obtidos neste trabalho são inéditos na literatura carcinológica, sendo de grande valia no manejo populacional e preservação desta espécie, que vem sendo intensamente explorada e usada como isca na pesca esportiva.The biology of freshwater crab Dilocarcinus pagei Stimpson, 1861 has been poorly studied, mainly in relation to growth in the Trichodactylidae species. This study aims to determine size/weight growth curves, longevity and age in the puberty molt of the freshwater crab Dilocarcinus pagei Stimpson, 1861. The samples were taken monthly in the São José do Rio Preto county dam (São Paulo, from October 1994 to September 1996, the individuals being sexed, measured (CW = cephalotorax width and weighed (WW = wet weight. Growth was determined by distribution of the specimens by size classes, where as the FiSAT program was used to determine non-linear estimation of growth parameters by the Bertalanffy equation. A total of 962 specimens (534 males and 428 females was analyzed. Growth size curves were expressed by the equations CW Males = 61.7[1-e-0.97(t+0.041] and CW Females = 57.1[1-e-1.41(t+0.031], while growth in weight was better represented by WW Males = 65.2[1-e-0.97(t+0.041]3.08 and WW Females = 44.9[1-e-1.41(t+0.031]2.82. Assintotic size of the males (61.7 mm was greater than that of the felamles (57.1 mm, the opposite occurring for longevity, estimated at 2.4 and 2.7 years, respectively. The maximum size (95% of the CW¥ was 58.6 mm for males and 54.2 mm for females, very close to maximum sizes recorded in nature to each sex (55.8 mm. The puberty molt in males occurred at a higher age level when compared to that of females (tMales = 1.2 years and tFemales = 0.9 years. The results present here are inedited in the carcinological literature, this being very important in population management and preservation of this species, as it is explored intensely and used as bait in fishing.

  4. Uma armadilha para captura de Porcellanidae (Crustacea, Decapoda do mediolitoral de praias rochosas A trap for capturing porcellanidae (Crustacea, Decapoda from midlittoral of rocky shores

    Directory of Open Access Journals (Sweden)

    Edinalva Oliveira

    1995-01-01

    Full Text Available A simple net trap for capturing agile porcelain crabs living amongst superposed stones of the midlittoral rocky shore was developed. About a hundred pebbles and boulders were dislodged from I m² area and Im depth, so that a pit was formed. A sheet net of Im² and Imm mesh size was spread on the bottom of this pit and the stones were replaced again, like the original condition. After a cicle of high tide (about 12 hours, the same stones in the pit were carefully searched by dislodging and by rinsing them. The porcelain crabs were slowly getting out from the handling stones towards the bottom until they found the net sheet. The net border was lifted and the animais captured. The density of population sampled with the aid of the net trap was about 50% higher than that collected by hand. Also, small size species and early developmental stages were adequately collected in this trap. However, the sampling by hand also showed a good performance, as all species of Porcellanidae known from Farol isle and all developmental stages of those species were registered in this collection methodology.

  5. Isopoda (Crustacea do complexo estuarino-lagunar Mundaú/Manguaba, Alagoas, Brasil Isopoda (Crustacea from the estuary-lagoon complex Mundaú/Manguaba, Alagoas, Brasil

    Directory of Open Access Journals (Sweden)

    Jayme de Loyola e Silva

    1994-01-01

    Full Text Available Qualilative and quantitative studies of Isopoda species were made at Mundaú/Manguaba Estuary-Lagoon Complex on the Coast of Alagoas State. Six points were established in order to carry out methodical collections of animals. These collections were made monthly, without interruption, from April, 1990 to March, 1991, in which three families, five genera and seven species of Isopoda were identified. A special key for identification of Isopoda and also diagnosis for each species are presented. Sphaeromatidae Family was the most significant and Cassidinidea fluminensis (Mane-Garzón, 1944, was the species with numerical dominance. Space/time distribution of the species of Isopoda was related to the variation of salinity.

  6. Crescimento relativo em Uca leptodactyla Rathbun (Crustacea Decapoda Ocypodidae Relative growth in the fiddler crab Uca leptodactyla Rathbun (Crustacea Decapoda Ocypodidae

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    Setuko Masunari

    2003-09-01

    Full Text Available Relative growth of the male major chela and female abdome was studied in a population of the fiddler crab Uca leptodactyla Rathbun, 1898 from Itapoá, Santa Catarina coast, southern Brazil. Major chela length (CMQ was measured from 191 males, and abdomen width (LAB from 128 females. Carapace width (LC was the reference dimension for both sexes, which ranged from 3.9 to 11.5 mm for males, and from 3.15 to 10.65 mm for females. Males grew bigger than females. Relationship between CMQ and LC showed a transition point at 8.35 mm LC in males, and between LA and LC at 7.10 mm LC in females. Growth was allometrically positive in the early ontogenesis and isometric after the puberal molting for both sexes. Regressions between LC and CMQ in males read as: logCMQ = -0,854536 + 2,19. logLC for empirical points at left of critical point and logCMQ = 0,063047 + 1,24. logLC for those at right. In females, this relation was logLAB = -0,603590 + 1,30. logLC and logLAB = -0,361464 + 1,07. logLC, respectively. These body dimensions were connected with reproductive activity of this species.

  7. Tanaidáceos (Crustacea: Peracarida de los litorales de Guerrero y Oaxaca, México Littoral tanaidaceans (Crustacea: Peracarida from Guerrero and Oaxaca, Mexico

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    Jani Jarquín-González

    2010-10-01

    Full Text Available Los tanaidáceos son componentes esenciales de las cadenas tróficas del bentos marino, son fuente de alimento para especies de relevancia comercial y para otros organismos marinos. A pesar de su importancia, el conocimiento del grupo se ha rezagado debido a los problemas relacionados con su biología y taxonomía, y por la carencia de muestreos exhaustivos y sistemáticos; así, en las costas de Guerrero y Oaxaca sólo se había registrado 1 género. Por lo anterior, el objetivo fue conocer la composición específica y los patrones de distribución de los tanaidáceos litorales de Guerrero y Oaxaca. De 4 275 ejemplares, se identificaron 6 familias y 9 morfotipos: Hexapleomera robusta, Sinelobus stanfordi, Leptochelia cf. dubia, Paratanais cf. denticulatus, Paradoxapseudes cf. garthi, Apseudormorpha sp., Cyclopoapseudes cf. indecorus, Synapseudes sp. y Parapseudes pedispinis. Todos son registros nuevos para el litoral de Guerrero y Oaxaca. Se amplía el intervalo de distribución hacia el norte, para H. robusta de islas Galápagos a Guerrero. Para S. stanfordi y P. pedispinis se proporcionan localidades intermedias que rompen con la distribución disyunta previa en el Pacífico oriental. Hay 6 especies, posiblemente nuevas, con distribución restringida; 2 son de amplia distribución y 1 restringida al Pacífico oriental tropical.The tanaidaceans are essential components in food chains of marine benthos, since they are the main food source for commercially important species and other marine organisms. Despite their importance, problems related to their biology and taxonomy have delayed the understanding of the group, as observed on the coasts of Guerrero and Oaxaca, where only 1 genus was previously known. The aim was to determine the species richness and distribution patterns of littoral tanaids from Guerrero and Oaxaca. A total of 4 275 specimens were collected and 6 families and 9 morphotypes have been identified: Hexapleomera robusta, Sinelobus stanfordi, Leptochelia cf. dubia, Paratanais cf. denticulatus, Paradoxapseudes cf. garthi, Apseudormorpha sp., Cyclopoapseudes cf. indecorus, Synapseudes sp. and Parapseudes pedispinis. All species are new records for the littorals of Guerrero and Oaxaca. Hexapleomera robusta increased the range distribution to the north, from the Galapagos to Guerrero; and S. stanfordi and P. pedispinis are the first intermediate records for a previously disjunct distribution in the East Pacific. With respect to the distribution patterns, 6 species have restricted distribution, represented by possible new species; 2 species have a wider distribution, and 1 species has restricted distribution to the tropical eastern Pacific.

  8. Palaemonidae (Crustacea: Decapoda: Caridea from the shallow waters from Quintana Roo, Mexican Caribbean coast Palaemonidae (Crustacea: Decapoda: Caridea de las aguas someras de Quintana Roo, Caribe mexicano

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    Ramiro Román-Contreras

    2010-04-01

    Full Text Available Few studies have focused on the palaemonid fauna of the Mexican Caribbean. This study provides a list of shallow water free-living and symbiont shrimps of the family Palaemonidae collected on turtle grass (Thalassia testudinum in Bahía de la Ascensión, Bahía del Espíritu Santo and Mahahual reef lagoon, Quintana Roo, Mexico. Ten species in 8 genera are reported, of which the genus Periclimenes is the most diverse with 3 species. An updated geographic distribution along the western Atlantic and other regions is provided for all the species. The greatest affinity of the palaemonid fauna studied, besides that with the Caribbean province, is with the Brazilian, Argentinian, and Texan zoogeographic provinces. Of the 10 species reported in this paper, 8 represent new local records in the studied area.Los crustáceos de la familia Palaemonidae del Caribe mexicano han sido poco estudiados. En este trabajo se presenta un listado de palemónidos de vida libre y simbiontes recolectados en el pasto marino Thalassia testudiuim de Bahía de la Ascensión, Bahía del Espíritu Santo y la laguna arrecifal de Mahahual, Quintana Roo, México. Se registran 10 especies pertenecientes a 8 géneros, siendo el género Periclimenes el más diverso con 3 especies. Para todas las especies se proporciona su distribución geográfica en la costa del Atlántico americano así como en otras regiones. Además de la provincia Caribeña, los palemónidos recolectados también muestran alta afinidad con otras provincias zoogeográficas como la Brasileña, Argentina y Texana; de las 10 especies registradas en este estudio, 8 representan nuevo registro local en el área estudiada.

  9. A new species of Benthana (Crustacea: Isopoda: Philosciidae from southern Brazil Uma nova espécie de Benthana Budde-Lund (Crustacea: Isopoda: Philosciidae sul do Brasil

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    Carolina C. Sokolowicz

    2008-06-01

    Full Text Available A new species of Benthana Budde-Lund, 1908 is described from southern Brazil. Benthana cairensis sp. nov. is distinguished from the other species in the genus by having 17 aesthetascs on the antennula and the elongated male pleopod 1 exopod with a lobe on the inner lateral margin and up to six setae on the outer lateral margin. The new species most resembles B. olfersii (Brandt, 1833, but may be distinguished by lacking the lobe with six setae on the internal margin of the proximal extremity of the merus of pereiopod 7. Furthermore, we include B. olfersii in the subgenus Benthanoscia based on the examined material as described herein.Uma nova espécie de Benthana Budde-Lund, 1908, é descrita de material coletado no sul do Brasil. B. cairensis sp. nov. distingue-se das outras espécies do gênero por apresentar 17 estetascos na antênula e o exópode do pleópode 1 do macho alongado, com um lobo e portando seis setas na margem lateral externa. A nova espécie assemelha-se a B. olfersii (Brandt, 1833 em várias características, mas pode ser diferenciada pela ausência do lobo com seis setas na margem externa da extremidade proximal do mero do pereiópodo 7. Além disso, B. olfersii é incluída, neste trabalho, no subgênero Benthanoscia, com base no material examinado.

  10. Biologia reprodutiva e ecologia de Aegla leptoaectyla Buckup & Rossi (Crustacea, Anomura, Aeglidae Biology and ecology of Aegla leptodactyla Buckup & Rossi (Crustacea, Anomura, Aeglidae

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    Clarissa Köhler Noro

    2002-12-01

    Full Text Available The crustaeeans of Aeglidae family oeeur in South America's fresh water enviranments, featuring as important links in the food chains. The present article has the intention to give an acount of the results from investigations made from April/2000 to July/2001 on the biological and ecological features of Aegla leptodactyla Buckup & Rossi, 1977, an endemic species from the headwaters of the Rio Pelotas Basin in Rio Grande do Sul State, Brazil. The sampling was performed at the Rio da Divisa, tributary of Rio Pelotas, municipal district of São José dos Ausentes, Rio Grande do Sul. The animais were collected with a hand net (puçá at four different sites of the river. High contents of dissolved oxygen was verified, with a medium value of 108% and alow conductivity (avarage of 13.7mS/cm. The water mean temperature was 16ºC and the pH remained neutral, average of 7.5. The velocity of the water current varied from 0.54 to 0.78m/s. A total of 1,323 males and 1,112 females of A. leptodactyla was sampled. Ovigerous females were observed from April through September and the smallest egg bearing female measured 14.09 mm cephalothorax length. The recruitment took place in November and December. The sex-ratio of the population was 1.19 males for 1 female.

  11. Fertilizers for Daphnia sp. (Crustacea, Cladocera production in experimental tanks Fertilizantes para produção de Daphnia sp. (Crustacea, Cladocera em tanques experimentais

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    Patrícia de Souza Lima Cunha

    2010-05-01

    Full Text Available The current study was aimed at investigating the use of different fertilizers - dicalcium phosphate, biosolid and quail feces - as a strategy for water fertilization in Daphnia sp production. It was used twenty-four 100-L tanks of asbestos cement distributed in a completely randomized split-plot design with six replicates, with plots in the three kinds of fertilizers (biosolid, dicalcium phosphate, and quail feces and a control without fertilization (WF and subplots at the times of assessment (days 8 and 13. It was assessed the biomass production of Daphnia sp. and the following water quality parameters: chlorophyll a, electrical conductivity, pH, dissolved oxygen, temperature, ammonia and organic nitrogen, total phosphorus and total hardness. There was a significant correlation between the values of chlorophyll a and biomass weight of Daphnia sp, which indicates interactions between phytoplankton and zooplankton communities. The maximum weight of Daphnia sp. biomass is found in tanks fertilized with quail feces (35.98 g, followed by the biosolid (16.80 g, control without fertilization (6.75 g and dicalcium phosphate (5.24 g.Este trabalho foi conduzido com o objetivo de avaliar a utilização de fertilizantes - fosfato bicálcico, biossólido e fezes de codorna - na água de produção de Daphnia sp. Foram utilizados 24 tanques de cimento-amianto, cada um com volume útil de 100 L, em um delineamento inteiramente ao acaso em parcelas subdivididas com seis repetições, tendo nas parcelas os tipos de fertilizantes e um controle, sem adubação, e nas subparcelas as épocas de avaliação (dias 8 e 13. Foram avaliados a produção da biomassa de Daphnia sp. e os seguintes parâmetros de qualidade da água: clorofila a, condutividade elétrica, pH, oxigênio dissolvido, temperatura, nitrogênio amoniacal e orgânico, fósforo total e dureza total. Observou-se correlação significativa entre os valores de clorofila a e o peso da biomassa de Daphnia sp., o que indica interação entre as comunidades fito e zooplanctônicas. O peso máximo da biomassa de Daphnia sp. em tanques adubados com fezes de codorna é maior (35,98 g que em tanques adubados com biossólido (16,80 g, sem adubação (6,75 g ou adubados com fosfato bicálcico (5,24 g.

  12. Estrutura populacional e biologia reprodutiva de Parastacus defossus (Crustacea: Decapoda: Parastacidae Population structure and reproductive biology of Parastacus defossus (Crustacea: Decapoda: Parastacidae

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    Clarissa K. Noro

    2008-12-01

    Full Text Available Este trabalho descreve a estrutura populacional e aspectos da biologia reprodutiva de Parastacus defossus Faxon, 1898, uma espécie com hábito fossorial que passa sua vida no interior de galerias subterrâneas. Aproximadamente 30 exemplares foram coletados mensalmente, de janeiro de 2003 a agosto de 2005 na região do Lami, Município de Porto Alegre, Rio Grande do Sul, Brasil. Registrou-se o comprimento mínimo, máximo e médio da carapaça de machos, fêmeas, juvenis e animais com ootestículo. Analisou-se a distribuição de freqüência por classes de tamanho, a proporção sexual, o recrutamento e o período reprodutivo. Foram amostrados um total de 766 exemplares, 315 machos (41,12%, 278 fêmeas (36,30%, 166 juvenis (21,67% e sete animais com ootestículo (0,91%. Machos e fêmeas estiveram presentes durante todos os meses de amostragem e em todas as classes de tamanho, sendo que a maior freqüência de indivíduos foi registrada nas classes de tamanho ente 24 a 30 mm. A maior freqüência de juvenis foi observada na primavera/2003 e verão/2005. Diferenças significativas no tamanho de machos e fêmeas foram registradas apenas nas classes de tamanho entre 26-30 mm. A proporção sexual no período amostral foi de 1:0,88 (x² = 2,3; p > 0,05 e entre as classes de tamanho foram constatadas diferenças significativas nas classes de tamanho 26-28 mm (x² = 5,43; p This study investigates the population structure and the reproductive biology of Parastacus defossus Faxon, 1898, a fossorial species that spends its life inside subterranean tunnels. Around 30 specimens were collected each month in the region of Lami, municipality of Porto Alegre, state of Rio Grande do Sul, Brazil, from January, 2003 to August, 2005. The minimum, the maximum, and the mean carapace length of males, females, juveniles and individuals with ootestis were recorded. The frequency distribution by size classes, the sexual proportion, the recruitment, and the reproductive period were analyzed. A total of 766 specimens were collected, from which 315 were males (41.12%, 278 were females (36.30%, 166 were juveniles (21.67%, and seven individuals had ootestis (0.91%. Males and females were present in all months and in all size classes. The highest frequency of individuals matched the size classes from 24 to 30 mm. The highest frequency of juveniles was recorded during the spring of 2003 and the summer 2005. Significant differences in the size of males and females were recorded in the size classes between 26 and 30 mm. The sex ratio between all males and females was 1:0.88 (x² = 2.3, p > 0.05. The proportion between males and females showed significant differences between the size classes 26-28 mm (x² = 5.43, p < 0.05 and 28-30 mm (x² = 4.77, p < 0.05 carapace length, were the number of males was highest. Of the 278 females, only 17 were ovigerous (6.11% and the reproductive period was clearly restricted to the spring.

  13. Atividade nictimeral e tempo de digestão de Aegla longirostri (Crustacea, Decapoda, Anomura Diel activity and digestion time of Aegla longirostri (Crustacea, Decapoda, Anomura

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    Carolina C. Sokolowicz

    Full Text Available O objetivo do presente trabalho foi caracterizar o ritmo de atividade e tempo de digestão em Aegla longirostri Bond-Buckup & Buckup, 1994. Os animais foram coletados em Santa Maria, RS, Brasil. Em laboratório, os animais foram transferidos para aquários individuais (5L. Para testar a atividade locomotora e alimentar dos aeglídeos um grupo de animais permaneceu sob luminosidade constante durante 12 horas, enquanto outro grupo permanecia no escuro, essa condição sendo invertida a cada 12 horas. As observações foram realizadas a cada 6 horas. Para determinar o tempo de digestão os animais foram alimentados e a cada 30 minutos um indivíduo era sacrificado. Aegla longirostri mostrou menor atividade em períodos de luminosidade, o que aconteceu nos dois grupos de animais. Essa espécie leva aproximadamente 5 horas para concluir a digestão extracelular. Os resultados sugerem que A. longirostri possui hábitos noturnos e provavelmente se alimenta sempre que há recursos disponíveis.The aim of this work was to characterize the diel activity rhythm and time of digestion in Aegla longirostri Bond-Buckup & Buckup, 1994. The individuals were collected in Santa Maria, RS, Brazil. In laboratory, the animals were kept in individuals glass aquariums (5L. To test locomotor and feeding activity of the aeglids, a group remained under constant luminosity for 12 hours, while another group was mantained in the dark, this condition being reversed at each 12 hours. The observations were taken at every 6 hours. For the determination of digestion's time the animals were fed, and one individual was sacrificed at each 30 minutes. Aegla longirostri showed lower activity in periods of light time. This condition was recorded for both groups of animals. This species takes approximately 5 hours to conclude its extracellular digestion. The results suggest that A. longirostri has nocturnal habits and probably feeds whenever resources are available.

  14. Shallow-water anomuran and brachyuran crabs (Crustacea: Decapoda from southern Bahia, Brazi l Cangrejos anomuros y braquiuros (Crustacea: Decapoda de aguas someras del sur de Bahia, Brasil

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    Alexandre O Almeida

    2010-01-01

    Full Text Available The objective of this study was to determine the taxonomic composition and ecological aspects of decapods crustacean species belonging to the infraorders Anomura and Brachyura in shallow marine and estuarine waters from southern Bahia, a coastline about 640 km in extent, corresponding to approximately 7% of the Brazilian coast. Sixteen species of the infraorder Anomura and 68 of the infraorder Brachyura are reported for the study area. The most important families in terms of number of species were the Panopeidae with 11 species, and the Ocypodidae and Portunidae with 9. Among the Brachyura, the southern distribution of the species Austinixa leptodactyla Coelho, 1997 (Pinnotheridae, endemic to Brazil, is extended from the coast of Sergipe to Bahía (Prado, Cumuruxatiba Beach, 17°06'18.6"S, 39°10'50.4"W. The ocypodid Uca (Leptuca cumulanta Crane, 1943 and also the pinnotherids Austinixa aidae (Righi, 1967 and Fabia byssomiae (Say, 1818 are reported for the first time from the Bahia coast. The specimen of F. byssomiae examined was collected in the mantle cavity of the clam Macoma constrict (Bruchiére, 1792 (Bivalvia: Tellinidae, a new host record for the species.El objetivo del presente estudio fue determinar la composición taxonómica y aspectos ecológicos de los crustáceos decápodos pertenecientes a los infraórdenes Anomura y Brachyura, en aguas someras, marinas y estuarinas del sur de Bahia, Brasil, una línea costera con cerca de 640 km de extensión, que corresponde aproximadamente al 7% de la costa brasileña. Para esta area de estudio se registraron 16 especies del infraorden Anomura y 68 del infraorden Brachyura. Las familias más representativas en términos de número de especies fueron Panopeidae, con 11 especies, y Ocypodidae y Portunidae, ambas con nueve especies. Entre los Brachyura, la distribución meridional de Austinixa leptodactyla Coelho, 1997 (Pinnotheridae, endémica del Brasil, se extiende desde la costa de Sergipe hasta la costa de Bahia (Municipalidad de Prado, Playa de Cumuruxatiba, 17°06'18.6"S, 39°10'50.4"W. Se reportó por primera vez para Bahia el ocipódido Uca (Leptuca cumulanta Crane, 1943, al igual que los pinotéridos Austinixa aidae (Righi, 1967 y Fabia byssomiae (Say, 1818. El único espécimen de F. byssomiae fue recolectado al interior de la cavidad paleal del molusco Macoma constricta (Bruchiére, 1792 (Bivalvia: Tellinidae, representando un nuevo huésped para esta especie.

  15. Water Quality And Sediment Evaluation for Inner Harbor Navigation Canal Lock Replacement Project, New Orleans, Louisiana

    Science.gov (United States)

    2011-08-01

    118 Figure 29. Hyalella azteca 10-day freshwater solid phase toxicity tests. .......................................... 123 Figure 30. Benthic...toxicity evaluation. Mean percent survival of Hyalella azteca exposed to IHNC dredged material...121 Table 40. Hyalella azteca 10-day freshwater solid phase toxicity tests

  16. New Record of Two Xanthid Crabs (Crustacea: Decapoda: Xanthidae from Korea

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    Lee, Sang-Kyu

    2014-10-01

    Full Text Available Xanthid crabs, decapod crustacean, with the black coloured fingers, are easily found under rocks or stones in the intertidal or subtidal zones. Two xanthids, Etisus laevimanus Randall, 1840 and Paraxanthias elegans (Stimpson, 1858, were newly reported in Korean waters as part of continuous taxonomic studies on crabs. The genus Paraxanthias Odhner, 1925 was also reported for the first time in Korea. Of these, the examined specimen of P. elegans showed eight feathery hairs on the subdistal tip of the first gonopod, which differs from the description of Dai and Yang at 1991. Here, the descriptions and illustrations of these species are provided. Korean Xanthoidea currently consists of 30 species belonging to 25 genera.

  17. Intersexuality in the porcellanid crab Pisidia longicornis (Crustacea: Decapoda: Anomura: Porcellanidae

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    Luciane Augusto de Azevedo Ferreira

    2015-04-01

    Full Text Available Intersex specimens of Pisidia longicornis (Linnaeus, 1767 are recorded for the first time and their secondary sexual characters are analyzed. Of 145 specimens of P. longicornis examined in this study, six were identified as intersex individuals. Of these, three presented male secondary sexual characters, well-developed male gonopores and rudimentary female gonopores, whereas the other three had female secondary sexual characters, with female gonopores being more pronounced than the male ones. The present study provides the first record of intersex porcelain crabs.

  18. Population genetic history of Aristeus antennatus (Crustacea: Decapoda in the Western and Central Mediterranean Sea.

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    Annamaria Marra

    Full Text Available Aristeus antennatus is an ecologically and economically important deep-water species in the Mediterranean Sea. In this study we investigated the genetic variability of A. antennatus sampled from 10 sampling stations in the Western and Central Mediterranean. By comparing our new samples with available data from the Western area, we aim to identify potential genetic stocks of A. antennatus and to reconstruct its historical demography in the Mediterranean. We analyzed two regions of mitochondrial DNA in 319 individuals, namely COI and 16S. We found two main results: i the genetic diversity values consistent with previous data within the Mediterranean and the absence of barriers to gene flow within the Mediterranean Sea; ii a constant long-term effective population size in almost all demes but a strong signature of population expansion in the pooled sample about 50,000 years B.P./ago. We propose two explanation for our results. The first is based on the ecology of A. antennatus. We suggest the existence of a complex meta-population structured into two layers: a deeper-dwelling stock, not affected by fishing, which preserves the pattern of historical demography; and genetically homogeneous demes inhabiting the fishing grounds. The larval dispersal, adult migration and continuous movements of individuals from "virgin" deeper grounds not affected by fishing to upper fishing areas support an effective 'rescue effect' contributing to the recovery of the exploited stocks and explain their genetic homogeneity throughout the Mediterranean Sea. The second is based on the reproduction model of this shrimp: the high variance in offspring production calls for a careful interpretation of the data observed under classical population genetics and Kingman's coalescent. In both cases, management policies for A. antennatus will therefore require careful evaluation of the meta-population dynamics of all stocks in the Mediterranean. In the future, it will be particularly relevant to sample the deepest ones directly.

  19. Copepoda (Crustacea) associated with commercial and non-commercial Bivalvia in the East Scheldt, The Netherlands

    NARCIS (Netherlands)

    Stock, Jan H.

    1993-01-01

    Six species of Copepoda Poecilostomatoida of the families Myicolidae, Sabelliphilidae, Lichomolgidae, and Mytilicolidae are recorded from six different species of intertidal bivalves in the East Scheldt (The Netherlands), a branch of the southern bight of the North Sea. One bivalve species may harbo

  20. The epidemiology of Argulus spp. (Crustacea: Branchiura) infections in stillwater trout fisheries.

    Science.gov (United States)

    Taylor, N G H; Sommerville, C; Wootten, R

    2006-04-01

    Problem infections caused by species of the crustacean ectoparasite, Argulus, in UK stillwater trout fisheries appear to have increased in recent years. A cross-sectional study of 77 such fisheries was conducted to establish the perceived problem and the extent and severity of this problem, and to identify associated risk factors. An interview-based study was conducted in 2001 using a standardized questionnaire based on the management and infection status of each fishery in the previous year. Logistic regression was used to identify potential risk factors. Argulus spp. were perceived to cause economic losses in infected fisheries through a reduction in the number of anglers due to reduced aesthetic appeal and catchability of fish. Of the sites studied, 29% experienced such a problem infection in 2000. Argulus foliaceus was identified in all but one case and was found to be widely distributed throughout the UK. The remaining case was identified as Argulus coregoni. Three risk factors were associated with problem infections: the presence of an algal bloom, slow rates of stock turnover and whether water level dropped by <1 m during the summer months.

  1. First record of the Asian diaptomid Neodiaptomus schmackeri (Poppe & Richard, 1892 (Crustacea: Copepoda: Calanoida in Europe

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    Giuseppe Alfonso

    2014-06-01

    Full Text Available Albania, as well as a great part of the Balkan area in general, still suffers a lack of environmental studies especially in limnological research. The Dumre plateau, in Central Albania, is characterized by an extraordinary high number of karst lakes in a small geographic area. Despite their environmental peculiarity, very few biological data are to date available for these lakes, none on the zooplankton. For this reason, 15 water bodies located in the central area of the plateau were selected for a preliminary limnological survey carried out in the years 2008-2011. Neodiaptomus schmackeri (Poppe & Richard, 1892, a diaptomid calanoid copepod characterized by a South-Eastern Palearctic - Oriental distribution, and the most widely spread Neodiaptomus species in Asia, was found in 8 lakes of the Dumre area. This finding represents the first record of the species, and of the entire genus Neodiaptomus, for Europe. Several environmental variables were measured to characterize the lakes, and the co-occurring planktonic crustaceans were also identified. Taxonomical drawings and descriptions of the main morphological features of both sexes are herein provided in order to compare the Albanian populations of N. schmackeri with those of the native distribution area of the species. The possible causes which determined the occurrence of this non-indigenous species in several Dumre lakes are discussed.

  2. Can contrasting environmental conditions of mangroves induce morphological variability in Aratus pisonii (Crustacea: Brachyura: Sesarmidae?

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    Beatriz López-Sánchez

    2016-09-01

    Full Text Available Aratus pisonii is one of the most common crab species in Neotropical mangroves. It shows great plasticity in its life history traits, which makes it an interesting subject for comparative studies. This study evaluated the morphometric variability in five populations of A. pisonii inhabiting mangroves with different degrees of structural development under contrasting environmental conditions. Mangrove forests located on the northwest coast of Venezuela were studied during the rainy season in 2006. The results showed morphometric differences and interaction between sampling sites and sex (PERMANOVA, P=0.0001, as well as the presence of five morphological groups in males and four in females. The findings support the existence of sexual dimorphism. Females from the dwarf hypersaline mangrove showed a wide variability associated with the chelipeds. The differences in crab morphology between sites seem to be related to a combination of environmental factors that is unique for each habitat, leading to the formation of different morphological groups, in which the mangrove structural development (resource availability and salinity (which compromises the energy budget play an important role. The presence of more robust chelipeds in females from the dwarf hypersaline mangrove seems to reflect an adaptation to the biomechanical properties of the leaves (sclerophylly.

  3. Population biology of the crab Armases angustipes (Crustacea, Decapoda, Sesarmidae at Brazilian tropical coast

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    Marina de Sá Leitão C. de Araújo

    2014-06-01

    Full Text Available The semi terrestrial crabs are important elements of the fauna of coastal regions. The aim of this study was to analyze the population structure of Armases angustipes (Dana, 1852 at estuaries of the Ariquindá River, considered a non impacted area, and Mamucabas River, considered a few impacted area, on the south coast of state of Pernambuco, Brazil. The species occurred in all months of the year. The number of individuals per month varied, being higher in the months of transition between the seasons. This is probably due to significant seasonal variations of air and burrow temperature and burrow salinity. There was no sexual dimorphism in size of A. angustipes in the mangrove of Ariquindá River, but males were larger than females in the mangrove of Mamucabas River. In both estuaries, the sex ratio did not differ from Mendelian proportion, but showed a deviation for females. The analysis of temporal variation in sex ratio showed significant differences in some months of the year. These variations are due to cyclical events that act distinctly on each sex. In both estuaries, size classes of carapace width were equally represented by both sexes. The ovigerous females of A. angustipes occurred only in some months of the year, especially in summer, in both estuaries. Probably the high phytoplankton productivity observed in summer favors the reproductive activity, since these algae serve as food for the larvae. Specimens of the population of Rio Ariquindá are largest and wider than those of Mamucabas River. This fact, associated with the low abundance of crabs and the lower frequency of ovigerous females observed in Mamucabas River, is an indication that this population may be influenced by the environmental impacts that this estuary has received.

  4. [Abundance and body size of Menippe mercenaria (Crustacea: Brachyura), in artificial refuges in Quintana Roo, Mexico].

    Science.gov (United States)

    Cervantes-Martínez, A; Ramírez-González, A

    2001-01-01

    In Florida and Cuba the stone crab Menippe mercenaria (Say, 1818) is under strong fishing-pressure; nevertheless in the Mexican Caribbean it is considered as sub-utilized and poorly known resource. Artificial shelters ("condominios cubanos") were used to study relative abundance, age structure, claw length-carapace amplitude relation, and population in three seasons and four sectors at Bahía Ascension, Quintana Roo, Mexico. The abundance varied according to the sector and sampling season: population was higher in the south and during the north wind ("Nortes") season (January to March). The carapace amplitude was directly proportional to claw length (r2 = 0.83, 0.97 and 0.89; p < 0.05 in females, males and total, respectively). The results suggest that specimens with 37.5 and 67.5 mm of carapace amplitude are the most limited regarding refuge availability in the Bay.

  5. Experimental evaluation of Candonocypris novaezelandiae(Crustacea:Ostracoda) in the biocontrol of Schistosomiasis mansoni transmission

    Institute of Scientific and Technical Information of China (English)

    Fouad; Yousif; Sherif; Hafez; Samia; El; Bardicy; Menerva; Tadros; Hoda; Abu; Taleb

    2013-01-01

    Objective:To test Candonocypris novaezelandiae(Baird)(C.novaezelandiae),sub-class Ostracoda,obtained from the Nile,Egypt for its predatory activity on snail,Biomphalaria alexandrina(B.alexandrina),intermediate host of Schistosoma mansoni(S.mansoni)and on the free-living larval stages of this parasite(miracidia and cercariae).Methods:The predatory activity of C.novaezelandiae was determined on B.alexandrina snail(several densities of eggs,newly hatched and juveniles).This activity was also determined on S.mansoni miracidia and cercariae using different volumes of water and different numbers of larvae.C.novaezelandiae was also tested for its effect on infection of snails and on the cercarial production.Results:C.novaezelandiae was found to feed on the eggs,newly hatched and juvenile snails,but with significant reduction in the consumption in the presence of other diet like the blue green algae(Nostoc muscorum).This ostracod also showed considerable predatory activity on the free-living larval stages of S.mansoni which was affected by certain environmental factors such as volume of water,density of C.novaezelandiae and number of larvae of the parasite.Conclusions:The presence of this ostracod in the aquatic habitat led to significant reduction of snail population,infection rate of snails with schistosme miracidia as well as of cercarial production from the infected snails.This may suggest that introducing C.novaezelandiae into the habitat at schistosome riskv sites could suppress the transmission of the disease.

  6. Decapod Crustacea of the Central Paratethyan Ottnangian Stage (middle Burdigalian: implications for systematics and biogeography

    Directory of Open Access Journals (Sweden)

    Hyžný Matúš

    2015-06-01

    Full Text Available Decapod crustaceans from the Ottnangian (middle Burdigalian, Lower Miocene of the Western and Central Paratethys remain poorly known. In this study, we review and re-describe mud shrimps (Jaxea kuemeli, ghost shrimps (Gourretia sp., Calliax michelottii and brachyuran crabs of the families Leucosiidae, Polybiidae and Portunidae. A dorsal carapace of the genus Calliax is reported for the first time in the fossil record. Re-examination of the type material of Randallia strouhali (Leucosiidae and Geryon ottnangensis (Geryonidae resulted in a transfer of these species into Palaeomyra (Leucosiidae and Liocarcinus (Polybiidae, respectively. Achelous vindobonensis, originally described as a chela of a portunid crab, probably belongs to a member of Polybiidae and is provisionally treated as Liocarcinus sp. Only two species, J. kuemeli and C. michelottii, are also known from the Karpatian, the succeeding Paratethyan stage. In most cases, the decapod assemblages of the Ottnangian consist of rather shallow-water taxa whereas the assemblages of the Karpatian consist of deep-water taxa from the middle and outer shelf. The Central Paratethyan assemblages show similarities in genus composition to the Proto-Mediterranean and recent Indo-Pacific regions. Gourretia sp. represents the earliest occurrence of the respective genus in the fossil record. The Oligocene–Early Miocene appearance of Palaeomyra and Liocarcinus in the circum-Mediterranean implies that sources of present-day diversity hotspots in the Indo-Pacific trace to the Western Tethys (as for other decapod genera, although coeval decapod assemblages in the Indo-Pacific remain poorly known.

  7. Amphi-Atlantic distribution of the subterranean amphipod family Metacrangonyctidae (Crustacea, Gammaridea)

    NARCIS (Netherlands)

    Jaume, Damià; Christenson, Keith

    2001-01-01

    Members of the strictly stygobiont, continental subterranean amphipod family Metacrangonyctidae are reported for the first time outside the Old World. Two new species of Metacrangonyx are described from two widely separated localities in the Dominican Republic (Hispaniola), one facing the Caribbean

  8. Complete mitochondrial genome of the Antarctic amphipod Gondogeneia antarctica (Crustacea, amphipod).

    Science.gov (United States)

    Shin, Seung Chul; Cho, Jin; Lee, Jong Kyu; Ahn, Do Hwan; Lee, Hyoungseok; Park, Hyun

    2012-02-01

    The complete sequence of the mitochondrial genome of the Antarctic amphipod Gondogeneia antarctica was determined to be 18,424 bp in length, and to contain 13 protein-coding genes (PCGs), 22 tRNA genes, and large (rrnL) and small (rrnS) rRNA genes. Its total A+T content is 70.1%. The G. antarctica mitogenome is the largest known among those of crustaceans, due to the existence of two relatively large intergenic non-coding sequences. The PCG arrangement of G. antarctica is identical to that of the ancestral pancrustacean ground pattern, although the tRNA arrangement differs somewhat. The complete mitogenome sequences of 68 species of pancrustacea have been added to the NCBI database, only 4 of which represent complete mitogenome sequences from amphipods. This is the first report of a mitogenome sequence of an Antarctic amphipod, and provides insights into the evolution of crustacean mitochondrial genomes, particularly in amphipods.

  9. Feeding of the planktonic shrimp Lucifer faroni Borradaile, 1915 (Crustacea: Decapoda in the laboratory

    Directory of Open Access Journals (Sweden)

    Luz Amelia Vega-Pérez

    1996-01-01

    Full Text Available Feeding behavior of juveniles of the planktonic shrimp Lucifer faxoni Borradaile was studied in the laboratory under light and dark conditions. Newly-hatched nauplii and metanauplii of Artemio were used as prey organisms. The fecding raie of L. foxoni was dependent on prey size and prey density, but was not obviously affected by light or dark conditions. The capture of the prey tended to increase with longer exposure time to prey. The maximum ingestion rate was 17.28 and 13.40 nauplii.L. faxoni .d- , in the light and in the dark conditions, respectively.O comportamento alimentar de espécimens jovens de Lucifer faxoni Borradaile, em laboratório, sob condições de luz e escuro, foi estudado utilizando-se como alimento náuplios recém-eclodidos e metanáuplios de Artemio. Neste estudo a taxa de alimentação de L. faxoni foi influenciada pelo tamanho e concentração da presa, bem como pelo tempo de contato com a mesma. A atividade alimentar de L. faxoni foi maior em condições de luz, quando comparado com as condições de escuro. f- taxa máxima de ingestão calculada foi de 17,28 e 13,40 náuplios.L. faxoni .d- para as condições de luz e escuro, respectivamente.

  10. Role of maxilla 2 and its setae during feeding in the shrimp Palaemon adspersus (Crustacea: Decapoda)

    DEFF Research Database (Denmark)

    Garm, A; Hallberg, E; Høeg, J T

    2003-01-01

    The movements of the basis of maxilla 2 in Palaemon adspersus were examined using macro-video recordings, and the morphology of its setae was examined using both scanning and transmission electron microscopy. The basis of maxilla 2 performs stereotypical movements in the latero-medial plane and g...

  11. Diversity and Spatial Distribution of Extant Freshwater Ostracodes (Crustacea in Ancient Lake Ohrid (Macedonia/Albania

    Directory of Open Access Journals (Sweden)

    Julia Lorenschat

    2014-07-01

    Full Text Available We carried out an intensive sampling survey in ancient Lake Ohrid (Macedonia/Albania, covering all seasons, to determine total species number, relative species abundances and spatial distribution of Ostracoda. We identified 32 living species that belong to seven families (Candonidae, Ilyocyprididae, Cyprididae, Leptocytheridae, Limnocytheridae, Cytherideidae, and Darwinulidae and 15 genera (Candona, Fabaeformiscandona, Candonopsis, Cypria, Cyclocypris, Ilyocypris, Eucypris, Prionocypris, Bradleystrandesia, Herpetocypris, Dolerocypris, Amnicythere, Paralimnocythere, Cytherissa, and Darwinula. Six additional species were identified from empty carapaces and valves. Dominant families in Lake Ohrid were Candonidae and Limnocytheridae, representing 53% and 16% of all species, respectively. Prevalence of species flocks in these two families confirms the “young” ancient status of the lake. Amnicythere displays a preference for oligo-haline to meso-haline waters, but some species are found in saline environments, which suggests Lake Ohrid has a marine history. Recent studies, however, indicate fluvial/glaciofluvial deposition at the onset of Lake Ohrid sedimentation. Candona is the most diverse genus in Lake Ohrid, represented by 12 living species. Paralimnocythere is represented by five living species and all other genera are represented by one or two species. Reports of Candona bimucronata, Ilyocypris bradyi, Eucypris virens, Eucypris sp., Prionocypris zenkeri, Bradleystrandesia reticulate, Herpetocypris sp. 2, and Dolerocypris sinensis are firsts for this lake. Living ostracodes were collected at the maximum water depth (280 m in the lake (Candona hadzistei, C. marginatoides, C. media, C. ovalis, C. vidua, Fabaeformiscandona krstici, Cypria lacustris, C. obliqua and Amnicythere karamani. Cypria lacustris was overall the most abundant species and Cypria obliqua displayed the highest abundance at 280 m water depth. Principal environmental variables that influence ostracode distributions in Lake Ohrid are water depth and conductivity. In general, species richness, diversity and evenness were greater in waters <60 m deep, with highest values often found in the littoral zone, at depths <30 m. Candonids, however, displayed highest diversity in the sublittoral (30–50 m and profundal (50–280 m zones. The most frequent species encountered are taxa endemic to the lake (14 living species, which have a wide depth range (≤280 m, and display higher abundance with greater water depth. Non-endemic species were rare, limited to water depths <50 m, and were found mainly in the north part of the lake where anthropogenic pressure is high. Several cosmopolitan species were encountered for the first time, which suggests that these widespread species are new arrivals that may replace endemics as human impacts increase.

  12. Induction of ovarian growth in Aegla platensis (Crustacea, Aeglidae by means of neuroregulators incorporated to food

    Directory of Open Access Journals (Sweden)

    Alejandra V Cahansky

    2008-09-01

    Full Text Available The freshwater crab Aegla platensis was used as a model to induce ovarian growth by adding different neuroregulators to a pellet food formulation. Added compounds were the dopaminergic inhibitor spiperone or the enkephalinergic inhibitor naloxone, both of them at a dose of 10-8 mol/animal. Animals were fed on the enriched pellets twice a week. After 7 wk, the gonadosomatic index (GI was calculated as (gonad fresh weight / body fresh weight x 100. GI significantly increased only for those females fed on spiperone pellets, compared to a control group receiving pellets with no compound added. During the assayed period, spiperone would be reverting the arrest exerted by dopamine on the neuroendocrine stimulation of ovarian growth. On the other hand, for both spiperone and naloxone a higher GI was correlated to a higher lipid content of both gonads and/or hepatopancreas, suggesting an increased energetic demand in accordance with an active investment in reproduction. Rev. Biol. Trop. 56 (3: 1201-1207. Epub 2008 September 30.Se utilizó al anomuro de agua dulce Aegla platensis como modelo para inducir el crecimiento ovárico mediante el agregado de diferentes neuroreguladores a una formulación de alimento pelleteado. Los compuestos agregados fueron el inhibidor dopaminergico spiperona ó el inhibidor encefalinérgico naloxone, ambos a una dosis de 10-8 moles/animal. Los animales fueron alimentados dos veces a la semana con pellets enriquecidos con alguno de los neuroreguladores. Luego de 7 semanas, se calculó el índice gonadomático (IG como (peso gonadal fresco/ peso corporal fresco x 100. El IG mostró un incremento significativamente sólo en aquellas hembras alimentadas con pellets enriquecidos con spiperona, en comparación con un grupo control que recibió pellets sin agregado alguno. Durante el período ensayado, la spiperona estaría revirtiendo el arresto ejercido por la dopamina sobre la estimulación neuroendocrina del crecimiento ovárico. Por otro lado, para ambos grupos experimentales (spiperona y naloxone, un mayor valor de IG estuvo correlacionado a un mayor incremento del contenido de lípidos tanto en gonadas como en hepatopáncreas, sugiriendo una demanda energética incrementada en relación con una activa inversión en reproducción

  13. Some biological aspects of Mysidopsis juniae (Crustacea:Mysidacea) and its use in chronic toxicity tests

    Energy Technology Data Exchange (ETDEWEB)

    Badaro-Pedroso, C. [USP, Sao Paulo (Brazil)] Nipper, M.G. [NIWA, Hamilton (New Zealand)

    1995-12-31

    As part of the joint effort to develop marine toxicity tests with organisms abundant at the Brazilian coast, some aspects for the laboratory culture of M. juniae and its sensitivity to single chemicals were studied. Organisms fed a mixture of brine shrimp (Artemia sp.) nauplii and the microalgae Isochrysis galbana reached sexual maturity 10 days before animals fed brine shrimp nauplii only. Under best conditions, sexual maturity was reached on the 9th--11th day and newborn mysids hatched on the 16th--18th day, Short-term chronic toxicity tests were initiated with 7-day old mysids and exposure time was 11 days, with growth (length and dry weight) as test endpoints. Experiments were undertaken with zinc, copper, and ammonia. Zinc did not affect the organisms at concentrations between 0.018 and 0.1 mg/L, which were one order of magnitude lower than the average 96-h; LC50 value. The NOEC and LOEC values were the same for length and weight in some tests with copper and ammonia (Cu: 0.006 and 0.015 mg/L; NH{sub 3}: 0.32 and 0.87 mg/L, respectively), but revealed length as a more sensitive endpoint than weight in others (length NOEC and LOEC: 0.23 and 0.53 mgNH{sub 3}/L; weight: 0.53 and 0.99 mgNH{sub 3}/L, respectively). The authors speculate that this could be caused by time-dependent variations in the lipid content of the organisms. Length would be a steadier and more reliable endpoint for chronic toxicity tests with M. juniae. The results show that the method has potential applications for the evaluation and monitoring of contaminated marine systems along the Brazilian coast.

  14. Bio-ecological aspects of the hermit crab Paguristes calliopsis (Crustacea, Diogenidae from Anchieta Island, Brazil

    Directory of Open Access Journals (Sweden)

    Renata Biagi

    2006-09-01

    Full Text Available In southern Atlantic studies on hermit crab biology are scanty considering the local biodiversity. In this way, some population features of Paguristes calliopsis Forest and Saint Laurent, 1968 such as size frequency distribution, sex ratio and shell occupation in the natural environment were studied. Specimens were collected by means of scuba methods in the infralittoral area of the Anchieta Island. A total of 116 individuals were analyzed. Size measurements (minimum; maximum; mean shield length ± sd, respectively were 0.8; 4.5; 2.76 ± 0.79 mm for males and 2.28 ± 0.36 mm for females. The sex ratio was 1.47:1 in favor of males which prevailed in the largest size classes. The hermit crabs occupied shells from eleven gastropod species and Cerithium atratum (Born 1778 was significantly the most occupied one (75.86%. Significant correlations were not obtained in all regression analysis, demonstrating sexual differences on fitting of the occupied shells. In the studied area P. calliopsis population is small if compared with the other hermit crab populations. The shell utilization varies as a function of shell availability and hermit crabs interspecific competition, in relation to the other coexistent species.Os estudos sobre a biologia dos ermitões no Atlântico sul ocidental são escassos considerando-se a biodiversidade local. O presente trabalhou caracterizou a população do ermitão Paguristes calliopsis Forest and Saint Laurent, 1968 quanto à distribuição de freqüência de tamanho dos indivíduos, ao sex-ratio, e a ocupação das conchas no ambiente natural. Os exemplares foram coletados por mergulho autônomo na região infralitoral da Ilha Anchieta. Um total de 116 indivíduos foi analisado. O tamanho do comprimento do escudo cefalotorácico (mínimo; máximo; média ± sd, respectivamente dos indivíduos variou de: 0.8; 4.5; 2.76 ± 0.79 mm para machos e 2.28 ± 0.36 mm para fêmeas. O sex-ratio foi de 1.47:1 em favor dos machos, sendo estes os que prevaleceram nas maiores classes de tamanho. Os ermitões ocuparam conchas de 11 espécies de gastrópodes sendo Cerithium atratum (Born 1778 significativamente a concha mais ocupada (75.86%. Não foram obtidas correlações significativas em todas as análises de regressão, demonstrando diferenças entre os grupos sexuais quanto a adequação das conchas ocupadas. Na área estudada a população de P. calliopsis pode ser considerada pequena quando comparada com as outras populações coexistentes. O padrão de utilização de conchas variou em função da disponibilidade destas e da competição interespecífica.

  15. [Artemia sp. (Crustacea, Anostracea) as intermediate host of Eurycestus avoceti Clark, 1954 (Cestoda, Cyclophyllidea) (author's transl)].

    Science.gov (United States)

    Gabrion, C; MacDonald, G

    1980-01-01

    Examination of Artemia sp. (Crustacé, Anostracé) for natural infection by cysticercoids of Flamingolepis liguloides, Cestode of the Flamingo (Phoenicopterus ruber) shows the presence of three other cysticercoids of cestode parasites of the Flamingo in the hemocoele of the Branchiopode. A fourth one is reported as the cysticercoid of Eurycestus avoceti, Clark, 1954, which parasitizes the Avocet (Recurvirostra avosetta). The systematic position of this Cestode is always unknown. This report shows the importance of Artemia in the life cycle of Cestodes of Anseriforms and Charadriiforms birds in saline lagoons.

  16. Microcassiope minor (Dana, 1852: a description of the first stage zoea (Crustacea: Decapoda: Brachyura: Xanthidae

    Directory of Open Access Journals (Sweden)

    P.F. CLARK

    2012-12-01

    Full Text Available The first stage zoea of Microcassiope minor (Dana, 1852 is described, illustrated and compared with thirteen other known Xanthinae. This comparison suggests that M. minor is closely related to another Atlantic Ocean xanthid, Nanocassiope melanodactyla (A. Milne-Edwards, 1867. Such an affinity may indicate that the genus Nanocassiope Guinot, 1967 is not a homogenous taxon.

  17. Macrurans (Crustacea, Decapoda) from the Lower Triassic (Olenekian) of the Ambilobé area (NW Madagascar)

    NARCIS (Netherlands)

    Garassino, Alessandro; Pasini, Giovanni; Teruzzi, Giorgio

    2003-01-01

    Fossil decapods of the Lower Triassic marine strata of Madagascar are reviewed. These display affiliation to the dendrobranchiates. These include Antrimpos madagascariensis, two species of Ifasya (I. madagascariensis and I. straeleni) and Ambilobeia karojoi.

  18. Shoaling of sergestid shrimp Acetes johni (Crustacea Decapoda: Sergestidae) associated with swarming of gammarid amphipods

    Digital Repository Service at National Institute of Oceanography (India)

    Goswami, S.C.

    zooplankton standing stock (5.81 ml.m/3). The sergestid shrimps and gammarid amphipods formed 94.7% of the zooplankton population, the former constituting more than half of the biomass of the sample. Their numerical abundance decreased with depth. The adaptive...

  19. Diversity and structure of the stomatopod (Crustacea community on the Amazon continental shelf

    Directory of Open Access Journals (Sweden)

    Kátia C. Araújo Silva

    2013-04-01

    Full Text Available The present study aimed to characterize the biodiversity of the Stomatopoda species found off the coast of the northern Brazilian states of Amapá and Pará, within the region's Exclusive Economic Zone. Two distinct sectors were surveyed, to the north and to the south of Cape Norte. The specimens were collected during fishery surveys carried out between 1996 and 1998 by the Revizee Program, using bottom shrimp trawl nets. The specimens were identified at the Crustaceans Laboratory of the Center for Research and Management of Fishery Resources of the Northern Coast and the Carcinology Laboratory of the Federal Rural University of Pernambuco. The 189 identified specimens represented Lysiosquilla scabricauda (Lamarck, 1818 (n = 2, Parasquilla meridionalis Manning, 1916 (n = 1, Squilla empusa Say, 1818 (n = 6, and Squilla lijdingi Holthuis, 1959 (n = 180. Only three species were collected in each of the survey sectors, with L. scabricauda and S. lijdingi being captured in both sectors. Squilla lijdingi was dominant in both sectors, whereas the other species were considered to be rare. Squilla lijdingi was very frequent in the northern sector, although the other stomatopods were infrequent. In the southern sector, L. scabricauda was sporadic, S. empusa was frequent, and S. lijdingi was very frequent. A significant difference was observed in the number of specimens captured in both sectors. The Shannon index was 0.6144 bits.ind-1 for the northern sector and 0.2708 bits.ind-1 for the southern one, whereas equitability was 0.3876 in the North and 0.1708 in the South. The stomatopods were collected at depths between 32 and 109 m, and were captured primarily on gravelly bottoms in the northern sector, and on muddy substrates in the southern sector. Stomatopods were more abundant in the northern sector during the dry season from June to November, whereas they were more common in the South during rainy season, from December to May.

  20. Athanas manticolus sp. nov., a new stomatopod-associated alpheid shrimp from Vietnam (Crustacea, Decapoda).

    Science.gov (United States)

    Duriš, Zdenek; Anker, Arthur

    2014-04-01

    A new species of the alpheid shrimp genus Athanas Leach, 1814 is described based on a single specimen, an ovigerous female from Nha Trang Bay, Vietnam. Athanas manticolus sp. nov. differs from all other species of Athanas by the presence of a small post-rostral tubercle, combined with a minutely toothed rostrum, reduced extra-corneal teeth, and the absence of infra-corneal and supra-corneal teeth. In addition, the new species is characterised by its unique colour pattern, particularly by the red chromatophores disposed in randomly oriented, short, narrow streaks. As its name suggests, A. manticolus sp. nov. is commensally associated with the burrows of the nannosquillid mantis shrimp Bigelowina phalangium (Fabricius, 1798).

  1. Out of the blue: the evolution of horizontally polarized signals in Haptosquilla (Crustacea, Stomatopoda, Protosquillidae).

    Science.gov (United States)

    How, Martin J; Porter, Megan L; Radford, Andrew N; Feller, Kathryn D; Temple, Shelby E; Caldwell, Roy L; Marshall, N Justin; Cronin, Thomas W; Roberts, Nicholas W

    2014-10-01

    The polarization of light provides information that is used by many animals for a number of different visually guided behaviours. Several marine species, such as stomatopod crustaceans and cephalopod molluscs, communicate using visual signals that contain polarized information, content that is often part of a more complex multi-dimensional visual signal. In this work, we investigate the evolution of polarized signals in species of Haptosquilla, a widespread genus of stomatopod, as well as related protosquillids. We present evidence for a pre-existing bias towards horizontally polarized signal content and demonstrate that the properties of the polarization vision system in these animals increase the signal-to-noise ratio of the signal. Combining these results with the increase in efficacy that polarization provides over intensity and hue in a shallow marine environment, we propose a joint framework for the evolution of the polarized form of these complex signals based on both efficacy-driven (proximate) and content-driven (ultimate) selection pressures. © 2014. Published by The Company of Biologists Ltd.

  2. Total mitochondrial genome of mantis shrimp, Squilloides leptosquilla (Brooks, 1886) (Crustacea: Stomatopoda: Squillidae) in Korean waters.

    Science.gov (United States)

    Kang, Hye-Eun; Kim, Jung Nyun; Yoon, Tae-Ho; Park, Kyeong Dong; Park, Won Gyu; Park, Hyun; Kim, Hyun Woo

    2016-07-01

    We characterized the complete mitochondrial genome of Squilloides leptosquilla (Brooks, 1886) collected from the southern waters of Korea, which is newly recorded into the Korean carcinological fauna. The total mitochondrial genome length of S. leptosquilla was 16,376 bp. This circular DNA encodes 13 proteins, two ribosomal RNAs, and 22 transfer RNAs, as well as a putative control region. Compared with other decapod crustacean mitochondrial genomes, the overall A + T content was relatively high (71.1%) as those among other stomatopod species. Nine and four protein-coding genes are encoded on the H-strand and on the L-strand, respectively. The short non-coding region (210 bp) between tRNA(Glu) and tRNA(Phe) may be the good candidate as the molecular marker to discriminate S. leptosequilla from other stomatopods.

  3. Insight on cellular and humoral components of innate immunity in Squilla mantis (Crustacea, Stomatopoda).

    Science.gov (United States)

    Gallo, Chiara; Schiavon, Filippo; Ballarin, Loriano

    2011-09-01

    For deeper insights into the function of crustacean haemocytes in immune responses, we studied the morphology and enzyme content of circulating cells of the mantis shrimp Squilla mantis from the North Adriatic Sea, together with their ability to phagocytose foreign cells. We also assayed the enzyme content and the agglutinating and haemolytic activities of cell-free haemolymph. Three haemocyte types, i.e., hyalinocytes, semigranulocytes and granulocytes, can be distinguished, according to cell and nuclear morphology and the presence of cytoplasmic granules. All of them share the same patterns of enzyme activities and are recognised by the same lectins. Spreading cells (hyalinocytes and semigranulocytes) can ingest foreign cells; granules of semigranular and granular cells have similar cytochemical properties. Injection of Micrococcus luteus into the heart sinus results in an increase in the frequency of hyaline cells and a decrease in the frequency of granulocytes. After 24 h from the injection, a decrease in the number of phagocytosing hyalinocytes, and a general decrease in the frequency of acid phosphatase-positive cells was reported. Our data match previous results and suggest the existence of a single differentiation pathway for Squilla haemocytes with the three haemocyte morphs as different stages of cell differentiation. Results also indicate that Squilla haemolymph performs immunosurveillance, through rapid changes in haemocyte distribution, increase of antimicrobial and antioxidant enzymes and secretion of lectins stimulating agglutination, phagocytosis and encapsulation. Copyright © 2011 Elsevier Ltd. All rights reserved.

  4. COMPARISON OF STRESS PROTEINS PARTICIPATION IN ADAPTATION MECHANISMS OF BAIKALIAN AND PALEARCTIC AMPHIPOD (AMPHIPODA; CRUSTACEA SPECIES

    Directory of Open Access Journals (Sweden)

    Timofeyev M.A

    2006-03-01

    Full Text Available The aim of the present study was a study of the influence different stressful factor on syntheses and activity of the stress proteins (HSP70, sHSP and peroxidase of freshwater organism. Six freshwater amphipod species were investigated: Eulimnogammarus cyaneus (Dyb., E verrucosus (Gerstf., E vittatus (Dyb. - endemic species from Lake Baikal which were compared with Palearctic species - Gammarus lacustris Sars., G tigrinus (Sexton, Chaetogammarus ischnus (Stebbins. It was shown expression of sHSP by heat and toxic stresses for all amphipods species. Oxidative stress induced HSP70 for Palearctic species G tigrinus and C ischnus but not for baikalian species. Heat stress did not caused the increase of HSP70 level for Baikalian species of amphipods. The activity of the peroxidase was decrease by heat and toxic stresses. Oxidative stress caused the increase of peroxidase activity for Palearctic species, and the decrease for Baikalian once.

  5. First records of parasitic copepods (Crustacea, Siphonostomatoida) from marine fishes in Korea.

    Science.gov (United States)

    Venmathi Maran, B A; Soh, H Y; Hwang, U W; Chang, C Y; Myoung, J G

    2015-06-01

    The knowledge of the biodiversity of parasitic copepods in South Korea is increasing. Interestingly we report here, some parasitic copepods considered as the first record of findings from Korea. Nine species of parasitic copepods (Siphonostomatoida) including six genera of three different families [Caligidae (7), Lernaeopodidae (1), Lernanthropidae (1)] were recovered from eight species of wild fishes in Korea: 1) Caligus hoplognathi Yamaguti & Yamasu, 1959 (♀, ♂) from the body surface of barred knifejaw Oplegnathus fasciatus (Temminck & Schlegel); 2) Caligus lagocephali Pillai, 1961 (♀) from the gills of panther puffer Takifugu pardalis (Temminck & Schlegel); 3) Euryphorus brachypterus (Gerstaecker, 1853) (♀, ♂) from the opercular cavity of Atlantic bluefin tuna Thunnus thynnus (Linnaeus); 4) Euryphorus nordmanni Milne Edwards, 1840 (♀, ♂) from the opercular cavity of common dolphin fish Coryphaena hippurus Linnaeus; 5) Gloiopotes huttoni (Thomson) (♀, ♂) from the body surface of black marlin Istiompax indica (Cuvier); 6) Lepeophtheirus hapalogenyos Yamaguti & Yamasu, 1959 (♀) from the gill filaments of O. fasciatus; 7) Lepeophtheirus sekii Yamaguti, 1936 (♀, ♂) from the body surface of red seabream Pagrus major (Temminck & Schlegel); 8) Brachiella thynni Cuvier, 1830 (♀) from the body surface of longfin tuna or albacore Thunnus alalunga (Bonnaterre); 9) Lernanthropinus sphyraenae (Yamaguti & Yamasu, 1959) (♀) from the gill filaments of moon fish Mene maculata (Bloch & Schneider). Since the female was already reported in Korea, it is a new record for the male of C. hoplognathi. A checklist for the parasitic copepods of the family Caligidae, Lernaeopodidae and Lernanthropidae of Korea is provided.

  6. Genesis of Hematopoietic Tissue and Its Relation with Hemocytes of Litopenaeus Vannamei (Boone, 1931 (Crustacea: Decapoda

    Directory of Open Access Journals (Sweden)

    Faiz Muhammad§, Zhi-Feng Zhang*, Ming-Yu Shao, Xiao-Li Shi and Muhammad Shafi

    2013-01-01

    Full Text Available The Litopenaeus vannamei is a prime aquaculture species and has a worth market value all over the world. In this study, we investigated the genesis and morphology of hematopoietic tissue (HPT and types of hemocyte based on its morphology and cytochemical feature using histological and histochemical methods. The results revealed that HPT in L. vannamei is not visible histologically in mysis and early two post larvae (P1 & P2, and emerges in P3 which locates in epigastric region. The HPT showed a continuous propagation of cells in successive post larval stages. Four types of cells can be identified in the HPT from adult specimen and mitotic activity is visible in the HPT. The hemocytes have been differentiated into five types and some of these types are co-related with the HPT cells. The cytochemical studies suggested that type I and II cells of hemocytes are PAS positive while scanty presence of prophenoloxidase was observed in type I cells. Similarly the type I cells are Sudan Black B positive and rest of the cells showed weak activity against lipid detective stain. This is the first effort towards genesis of HPT and its relation with circulating hemocytes in L. vannamei.

  7. A new species of the alpheid shrimp genus Triacanthoneus Anker, 2010 (Crustacea: Alpheidae) from Belize.

    Science.gov (United States)

    Alvarez, Fernando; Iliffe, Thomas M; Villalobos, José Luis

    2014-02-24

    A new species of the alpheid shrimp genus Triacanthoneus Anker, 2010, is described based on material collected in a marine cave off Caye Chapel, Belize. Triacanthoneus chapelianus sp. nov. is the fifth species in the genus and can be distinguished from the other four species by the position of the dorsolateral teeth on the carapace, which in the new species have an anterior (= submarginal) position, and by the configuration of the posterior margin of the telson, with a notch in the middle portion and two pairs of spines and one pair of plumose setae. A key to the five species of Triacanthoneus is provided.

  8. Diversity and distribution of freshwater amphipod species in Switzerland (Crustacea: Amphipoda).

    Science.gov (United States)

    Altermatt, Florian; Alther, Roman; Fišer, Cene; Jokela, Jukka; Konec, Marjeta; Küry, Daniel; Mächler, Elvira; Stucki, Pascal; Westram, Anja Marie

    2014-01-01

    Amphipods are key organisms in many freshwater systems and contribute substantially to the diversity and functioning of macroinvertebrate communities. Furthermore, they are commonly used as bioindicators and for ecotoxicological tests. For many areas, however, diversity and distribution of amphipods is inadequately known, which limits their use in ecological and ecotoxicological studies and handicaps conservation initiatives. We studied the diversity and distribution of amphipods in Switzerland (Central Europe), covering four major drainage basins, an altitudinal gradient of>2,500 m, and various habitats (rivers, streams, lakes and groundwater). We provide the first provisional checklist and detailed information on the distribution and diversity of all amphipod species from Switzerland. In total, we found 29 amphipod species. This includes 16 native and 13 non-native species, one of the latter (Orchestia cavimana) reported here for the first time for Switzerland. The diversity is compared to neighboring countries. We specifically discuss species of the genus Niphargus, which are often receiving less attention. We also found evidence of an even higher level of hidden diversity, and the potential occurrence of further cryptic species. This diversity reflects the biogeographic past of Switzerland, and suggests that amphipods are ideally suited to address questions on endemism and adaptive radiations, post-glaciation re-colonization and invasion dynamics as well as biodiversity-ecosystem functioning relationships in aquatic systems.

  9. Cladocera (Crustacea: Branchiopoda of South East Asia: history of exploration, taxon richness and notes on zoogeography

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    Nikolai M. Korovchinsky

    2013-08-01

    Full Text Available The history of Cladocera studies in South-East Asia is reviewed, beginning from the early start of explorations in the end of the 19th century by J. Richard and T. Stingelin. In the first half of the 20th century, extensive research was carried out by V. Brehm, who investigated material collected by the Wallacea-Expedition and the Deutschen Limnologischen Sunda-Expedition. Later, in the 1970-1980s, C.H. Fernando and collaborators, besides a few other researchers, provided a new series of regional studies of the cladoceran faunas together with the systematic revisions of some taxa from tropical Asia. Then and up to present, investigations of the Cladocera have concentrated in Thailand and many species have been revised and described as new to science. In total, 298 taxa of species rank have been recorded in SE Asia but only comparatively few of them (67 taxa; 22.5% can be regarded good species, of which the valid status has been confirmed by recent studies, while others are synonyms (68; 22.8% or taxa of uncertain taxonomic status, including those which definitely represent complexes of species (163; 54.7%. Most total taxa of species level and good species are known from Thailand (155 and 54, respectively, followed by Malaysia (plus Singapore, Indonesia, Philippines, Vietnam, and Cambodia in this respect (70-119 total taxa and 23-33 good species respectively. Laos, Burma (Myanmar and Brunei remain practically unexplored. Only good species were used for the zoogeographic analysis. Of them, about a quarter is known only in SE Asia but more species are distributed in tropical/subtropical/temperate Asia and Australia, others in tropics/subtropics of the eastern hemisphere (17.9% or even wider. Tropical species, constituting the primary part of the cladoceran fauna of SE Asia, can penetrate the neighboring subtropical and southern temperate zones to a different degree. Only a small fraction of species (7 or 10.5% here are of more or less northern origin, the are distributed predominantly in the subtropical/southern temperate or in the northern boreal latitudes. Few species are suggested to penetrate SE Asia from the north using the Mekong river and its tributaries. Generally, the cladocerans of SE Asia are poorly known and only continuous extensive taxonomic studies would improve this situation.

  10. Description of laboratory reared first zoea of Callinectes danae Smith (Crustacea, Decapoda, Portunidae)

    OpenAIRE

    Cheruparambil Sankarankutty; Sung Yun Hong; Kwang Bong Kim

    1999-01-01

    A detailed description of laboratory reared first zoea larva of Callinectes danae Smith, 1869 is given. The larvae utilized for this study were reared in vitro in a special incubator. A comparison with larvae of other species is also attempted.

  11. Descrição de um Novo Decapoda (Natantia, Malacostraca, Crustacea

    Directory of Open Access Journals (Sweden)

    Márcia Aparecida Fernandes dos Reis

    2005-08-01

    Full Text Available A “lobster” fossil from the Riachuelo Formation, Sergipe Sub-basin, is here described and placed in the Decapoda, Infraorder Palinura, based on the flattened carapace and the well-developed abdomen. The specimen is characterized by a dorsal median keel and a keel in each margin of the carapace and abdomen. Field data and petrographic studies suggest that the environment in which the Decapoda lived was probably a place with waves and moderate currents, located behind a sand barrier or in within a lagoon. Apparently, the carbonization process was responsible for specimen preservation.

  12. On a parthenogenetic population of Artemia (Crustacea, Branchiopoda from Algeria (El-Bahira, Sétif

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    Mounia Amarouayache

    2015-12-01

    Full Text Available The brine shrimp Artemia is a small crustacean of hypersaline lakes which is commonly used in larviculture. The parthenogenetic population of Artemia from El-Bahira Lake (10 ha area, situated in the High Plateaus of Northeastern Algeria (1034 m alt, has been characterized and surveyed during two hydroperiods of 2009 and 2013. Contrary to other known parthenogenetic populations, which develop in hot seasons and reproduce by ovoviviparity, Artemia from El-Bahira was found to develop only in cold seasons (winter and spring, even if the lake doesn’t dry in summer. It reproduces by oviparity and produces few cysts (5.69 ± 3.6 and 98.00 ± 28.32 offsprings/brood. Individual density was much lower during the hydroperiod of 2013, whereas fecundity was higher than in the previous hydroperiod (2009. Cyst reserve was estimated at 133.13 kg of dry weight which corresponds to a rate of 13.31 kg.ha-1.

  13. On a parthenogenetic population of Artemia (Crustacea, Branchiopoda) from Algeria (El-Bahira, Sétif)

    OpenAIRE

    Mounia Amarouayache; Naim Belakri

    2015-01-01

    The brine shrimp Artemia is a small crustacean of hypersaline lakes which is commonly used in larviculture. The parthenogenetic population of Artemia from El-Bahira Lake (10 ha area), situated in the High Plateaus of Northeastern Algeria (1034 m alt), has been characterized and surveyed during two hydroperiods of 2009 and 2013. Contrary to other known parthenogenetic populations, which develop in hot seasons and reproduce by ovoviviparity, Artemia from El-Bahira was found to develop only i...

  14. [Tissular alterations and defence reactions in cymothoids parasited teleosteans (Crustacea - Isopoda - blood sucking) (author's transl)].

    Science.gov (United States)

    Romestand, B; Janicot, M; Trilles, J P

    1977-01-01

    Some tissual alterations of the parasitic microbiotope are shown in fishes harbouring Cymothoidae (blood-sucking Isopods). These alterations consist mainly in a hypertrophied epidermis and a deeply disturbed conjunctive tissue; moreover, it can be observed an important production of mucus on the tegument surface and a rush of blood cells (lymphocytes, eosenophilic granulated cells) and of cells of histiocytary origin (giant multinucleated cells).

  15. Estudos sobre a morfologia de Parastacus brasiliensis (von Martens, 1869) (Crustacea, Decapoda, Parastacidae)

    OpenAIRE

    Ana Cristina Moura Horn

    2003-01-01

    A família Parastacidae inclui os crustáceos límnicos conhecidos como lagostins-de-água-doce. A espécie Parastacus brasiliensis (von Martens, 1869) é endêmica da região meridional brasileira, ocorrendo nas bacias que formam o estuário do Guaíba, na depressão central do Estado do Rio Grande do Sul. O presente trabalho reúne um estudo da organização morfológica do lagostim Parastacus brasiliensis. Os animais foram coletados, majoritariamente nas cabeceiras do Rio Gravataí e trazidos ao Laboratór...

  16. A new species of Munidopsis Whiteaves, 1874 (Crustacea: Decapoda: Anomura) from the Northwest Indian Ocean Ridge.

    Science.gov (United States)

    Dong, Dong; Li, Xinzheng; Zhou, Yadong; Wang, Chunsheng

    2016-08-23

    A new species, Munidopsis militaris n. sp., from the Carlsberg Ridge, Northwest Indian Ocean Ridge is described herein. The species belongs to a group of species having a pair of epigastric spines, mesial and lateral eye-spines, abdominal tergites unarmed, five or six spines on the lateral margin of the carapace, and a denticulate carina on the distolateral margin of the P1 fixed finger. It can be distinguished from its relatives by the spinous lateral margin of the palm and dorsal carinae on the P2-4 propodus. The Munidopsis fauna of the Indian Ocean Ridge is seldom reported on; this new species is the sixth member of this genus found inhabiting the Indian Ocean Ridge.

  17. Aspectos ecológicos dos Brachyura (Crustacea: Decapoda no manguezal do Itacorubi, SC - Brasil

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    Joaquim Olinto Branco

    1990-01-01

    Full Text Available Ecological studies including occurrence, relative abundance and spatial distribution of 15 species of Brachyura, as well as the fluctuation in the annual cycle are carried out in mangrove (27º 34' 14" and 27º 35' 31" L.S.; 48º 30' 07"and 48º 31' 33" L. W., during the year 1986. The hydrological parameters temperature, salinity and pH of surface and intersticial waters were also studied. Chasmagnathus granulata was the most abundant specie, followed by Uça uruguayensis, Aratus pisonii and Callinectes danae. The number of males was higher than females. In the spring a larger rate of Catches occurred. The species Eurytium limosum, Cardisoma guanhumi that had the state of São Paulo as their austral boundaru and Uça maracoani the state of Paraná, have now their boundaries of distribution expanded is for as the City of Florianópolis, in the state of Santa Catarina.

  18. Land and fresh water decapod crustacea from the Leeward Group and northern South America

    NARCIS (Netherlands)

    Chace, Fenner A.; Holthuis, Lipke B.

    1948-01-01

    This small paper consists only of an enumeration of the specimens collected by Dr. HUMMELINCK in 1936 and 1937, together with the records of land and fresh water decapods from the articles by RATHBUN (1936) and SCHMITT (1936) on the collections made in 1930. Identifications of many of the brachyuran

  19. Length and weight relationship of laboratory reared penaeid prawn Penaeus monodon (Fabricius) (Crustacea: Penaeidae)

    Digital Repository Service at National Institute of Oceanography (India)

    Saldanha, C.M.; Chatterji, A.

    followed the cube law. The weight of the prawn increased at the rate of more or less cube of the length. The relationship was found to be significant (p less than 0.001). At 95% confidence limit the b values were between 3.0524 and 4.3691. ANOVA showed...

  20. Stygofauna of the Canary Islands, 9. The amphipod genus Pseudoniphargus (Crustacea) in the Canary Islands

    NARCIS (Netherlands)

    Stock, Jan H.

    1988-01-01

    Pseudoniphargus was known from inland stygohabitats in the Iberian peninsula, the Azores, Madeira, N.W. Africa, and Bermuda, but not from the Canary Islands. Systematic sampling in six of the seven larger islands of the latter archipelago has revealed the presence of the genus in Tenerife (4 species

  1. Marine interstitial Amphipoda and Isopoda (Crustacea) from Santiago, Cape Verde Islands

    NARCIS (Netherlands)

    Stock, Jan H.; Vonk, Ronald

    1992-01-01

    Three species of Amphipoda are recorded from interstices of a marine beach on the island of Santiago, Cape Verde Archipelago: Cabogidiella littoralis n. gen., n. sp. (Bogidiellidae), Psammogammarus spinosus n. sp. (Melitidae), and Idunella sketi Karaman, 1980 (Liljeborgiidae). The latter, widely dis

  2. Reproductive variability of Parapandalus narval (Crustacea: Decapoda) along a depth gradient

    Science.gov (United States)

    Thessalou-Legaki, Maria

    1992-12-01

    The variations of the reproductive parameters of Parapandalus narval are studied from a population off Rhodos Island, Greece. Female size (CL), dry weight (FDW) and depth of occurrence are examined as determinants of the reproductive parameters such as the percentage of ovigerous females, the stage of egg maturation, the brood size and the reproductive effort. The percentage of the ovigerous females and the egg maturation are related to depth. More ovigerous, older females with larger eggs in earlier stages of development are found in deeper waters. Nevertheless, brood size or brood dry weight regressions on female size and dry weight, respectively, show that the shallow water reproductive output increases more steeply with size or weight of the females than does that in deeper waters. Finally, the reproductive effort of Parapandalus narval does not seem to be directly related to depth but it is related to the size of the female. Small females have smaller reproductive effort than bigger ones that reach a maximum value.

  3. Depth zonation in a Parapandalus narval (Crustacea, Decapoda, Pandalidae) population from Rhodos Island, Greece

    Science.gov (United States)

    Thessalou-Legaki, Maria; Frantzis, Alexis; Nassiokas, Kostas; Hatzinikolaou, Savas

    1989-09-01

    The population characteristics of Parapandalus narval are related to depth. Sex ratio (females/males and females) decreases with depth, while female size increases. Dry weight of equal sized individuals decreases with depth. For the 23 and 80 + 140 m females, the relative dry weight reduction was estimated to 10·3% and 16·0% compared to that of the 5 m females, respectively. Males (80-220 m) exhibited the greatest reduction of 19·9%. It is suggested that the depth zonation exhibited by the P. narval population is related to habitat differences along the depth range sampled and has to do with the exploitation of the available food resources by different sex and/or size groups.

  4. Food preference in the cultured species, Penaeus monodon Fabricius (Crustacea: Decapoda)

    OpenAIRE

    S. Khanum; Tirmizi, N.M.

    1997-01-01

    The study of food preference is necessitated by the need to promote coastal culture of shrimps in Pakistan. The cultured Penaeus monodon was selected for study. Food preferences have been examined through the analysis of the gut contents. The shrimp shows a seasonal variation in its preference to food and feeding.

  5. Diversity of the free-living marine and freshwater Copepoda (Crustacea) in Costa Rica: a review.

    Science.gov (United States)

    Morales-Ramírez, Álvaro; Suárez-Morales, Eduardo; Corrales-Ugalde, Marco; Garrote, Octavio Esquivel

    2014-01-01

    The studies on marine copepods of Costa Rica started in the 1990's and focused on the largest coastal-estuarine systems in the country, particularly along the Pacific coast. Diversity is widely variable among these systems: 40 species have been recorded in the Culebra Bay influenced by upwelling, northern Pacific coast, only 12 in the Gulf of Nicoya estuarine system, and 38 in Golfo Dulce, an anoxic basin in the southern Pacific coast of the country. Freshwater environments of Costa Rica are known to harbor a moderate diversity of continental copepods (25 species), which includes 6 calanoids, 17 cyclopoids and only two harpacticoids. Of the +100 freshwater species recorded in Central America, six are known only from Costa Rica, and one appears to be endemic to this country. The freshwater copepod fauna of Costa Rica is clearly the best known in Central America. Overall, six of the 10 orders of Copepoda are reported from Costa Rica. A previous summary by 2001 of the free-living copepod diversity in the country included 80 marine species (67 pelagic, 13 benthic). By 2009, the number of marine species increased to 209: 164 from the Pacific (49% of the copepod fauna from the Eastern Tropical Pacific) and 45 from the Caribbean coast (8% of species known from the Caribbean Basin). Both the Caribbean and Pacific species lists are growing. Additional collections of copepods at Cocos Island, an oceanic island 530 km away of the Pacific coast, have revealed many new records, including five new marine species from Costa Rica. Currently, the known diversity of marine copepods of Costa Rica is still in development and represents up to 52.6% of the total marine microcrustaceans recorded in the country. Future sampling and taxonomic efforts in the marine habitats should emphasize oceanic environments including deep waters but also littoral communities. Several Costa Rican records of freshwater copepods are likely to represent undescribed species. Also, the biogeographic relevance of the inland copepod fauna of Costa Rica requires more detailed surveys.

  6. Diversity of the free-living marine and freshwater Copepoda (Crustacea in Costa Rica: a review

    Directory of Open Access Journals (Sweden)

    Alvaro Morales-Ramírez

    2014-11-01

    Full Text Available The studies on marine copepods of Costa Rica started in the 1990’s and focused on the largest coastal-estuarine systems in the country, particularly along the Pacific coast. Diversity is widely variable among these systems: 40 species have been recorded in the Culebra Bay influenced by upwelling, northern Pacific coast, only 12 in the Gulf of Nicoya estuarine system, and 38 in Golfo Dulce, an anoxic basin in the southern Pacific coast of the country. Freshwater environments of Costa Rica are known to harbor a moderate diversity of continental copepods (25 species, which includes 6 calanoids, 17 cyclopoids and only two harpacticoids. Of the +100 freshwater species recorded in Central America, six are known only from Costa Rica, and one appears to be endemic to this country. The freshwater copepod fauna of Costa Rica is clearly the best known in Central America. Overall, six of the 10 orders of Copepoda are reported from Costa Rica. A previous summary by 2001 of the free-living copepod diversity in the country included 80 marine species (67 pelagic, 13 benthic. By 2009, the number of marine species increased to 209: 164 from the Pacific (49% of the copepod fauna from the Eastern Tropical Pacific and 45 from the Caribbean coast (8% of species known from the Caribbean Basin. Both the Caribbean and Pacific species lists are growing. Additional collections of copepods at Cocos Island, an oceanic island 530 km away of the Pacific coast, have revealed many new records, including five new marine species from Costa Rica. Currently, the known diversity of marine copepods of Costa Rica is still in development and represents up to 52.6% of the total marine microcrustaceans recorded in the country. Future sampling and taxonomic efforts in the marine habitats should emphasize oceanic environments including deep waters but also littoral communities. Several Costa Rican records of freshwater copepods are likely to represent undescribed species. Also, the biogeographic relevance of the inland copepod fauna of Costa Rica requires more detailed surveys.

  7. Thermal biology of the sub-polar–temperate estuarine crab Hemigrapsus crenulatus (Crustacea: Decapoda: Varunidae)

    Science.gov (United States)

    Cumillaf, Juan P.; Blanc, Johnny; Paschke, Kurt; Gebauer, Paulina; Díaz, Fernando; Re, Denisse; Chimal, María E.; Vásquez, Jorge; Rosas, Carlos

    2016-01-01

    ABSTRACT Optimum temperatures can be measured through aerobic scope, preferred temperatures or growth. A complete thermal window, including optimum, transition (Pejus) and critical temperatures (CT), can be described if preferred temperatures and CT are defined. The crustacean Hemigrapsus crenulatus was used as a model species to evaluate the effect of acclimation temperature on: (i) thermal preference and width of thermal window, (ii) respiratory metabolism, and (iii) haemolymph proteins. Dependant on acclimation temperature, preferred temperature was between 11.8°C and 25.2°C while CT was found between a minimum of 2.7°C (CTmin) and a maximum of 35.9°C (CTmax). These data and data from tropical and temperate crustaceans were compared to examine the association between environmental temperature and thermal tolerance. Temperate species have a CTmax limit around 35°C that corresponded with the low CTmax limit of tropical species (34–36°C). Tropical species showed a CTmin limit around 9°C similar to the maximum CTmin of temperate species (5–6°C). The maximum CTmin of deep sea species that occur in cold environments (2.5°C) matched the low CTmin values (3.2°C) of temperate species. Results also indicate that the energy required to activate the enzyme complex (Ei) involved in respiratory metabolism of ectotherms changes along the latitudinal gradient of temperature. PMID:26879464

  8. Amphipoda (crustacea) from palau, micronesia: families ampeliscidae, ampithoidae, aoridae, colomastigidae and cyproideidae.

    Science.gov (United States)

    Myers, Alan A

    2012-01-01

    12 species of amphipod in 5 families, collected from shallow reefs in Palau by S. DeGrave during 2002, are reported here. Of these, five species are new to science and Microdeutopus tridens Schellenberg (1938) is redescribed and transferred to the genus Bemlos Shoemaker (1925). The collection included several additional species in the genera Amphilochus Bate, 1862, Ampithoe Leach (1814), Bemlos, Byblis Boeck (1871), Colomastix Grube (1861) and Notopoma Lowry & Berents (1996), that were either incomplete or juvenile and could therefore not adequately be described. In addition, two new species of Plumithoe Barnard & Karaman (1991) are erected from the literature. Other families collected in Palau will be considered in later contributions.

  9. Amphipoda (Crustacea) from Palau, Micronesia: families Melphidippidae, Oedicerotidae, Photidae, Pleustidae, Podoceridae, Stenothoidae, Synopiidae and Talitridae.

    Science.gov (United States)

    Myers, A A

    2014-06-05

    Eleven species belonging to the families Melphidippidae, Oedicerotidae, Photidae, Pleustidae, Podoceridae, Stenothoidae, Synopiidae and Talitridae are recorded from Palau, Micronesia. Eight species are figured. One species is new to science and is described and figured. One species was previously known only from Australia, one only from Madagascar and one only from Fiji.

  10. Amphipoda (crustacea) from Palau, Micronesia: families Dexaminidae, Eusiridae, Hyalidae, Ischyroceridae, Leucothoidae and Lysianassidae.

    Science.gov (United States)

    Myers, A A

    2013-10-31

    Thirteen species of amphipod in the families Dexaminidae (1), Eusiridae (1), Hyalidae (1), Ischyroceridae (1), Leucothoidae (8) and Lysianassidae (1) are recorded from Palau in Micronesia. Of these, Ventojassa palauensis sp. nov., Leucothoe beobeldabensis sp.nov., L. pseudepidemos sp. nov., L. serratissima sp. nov., L. tumida sp. nov., L. whiteae sp. nov and Paranamixis dentidactylus sp. nov. are new to science and are described and figured.

  11. New species of Floresorchestia from Micronesia living in unusual habitats (Crustacea, Amphipoda, Talitridae).

    Science.gov (United States)

    Lowry, J K; Myers, A A

    2013-11-22

    The first freshwater talitrid, Floresorchestia pohnpei sp. nov., is described from the island of Pohnpei, Micronesia. Floresorchestia palau sp. nov. is described from supralittoral and shallow-water marine habitats in Palau, Micronesia.

  12. Amphipoda (Crustacea from Palau, Micronesia: Families Ampeliscidae, Ampithoidae, Aoridae, Colomastigidae and Cyproideidae

    Directory of Open Access Journals (Sweden)

    Alan Myers

    2012-05-01

    Full Text Available 12 species of amphipod in 5 families, collected from shallow reefs in Palau by S. DeGrave during 2002, are reported here. Of these, five species are new to science and Microdeutopus tridens Schellenberg (1938 is redescribed and transferred to the genus Bemlos Shoemaker (1925. The collection included several additional species in the genera Amphilochus Bate, 1862, Ampithoe Leach (1814, Bemlos, Byblis Boeck (1871, Colomastix Grube (1861 and Notopoma Lowry & Berents (1996, that were either incomplete or juvenile and could therefore not adequately be described. In addition, two new species of Plumithoe Barnard & Karaman (1991 are erected from the literature. Other families collected in Palau will be considered in later contributions.

  13. Jerbarnia stocki, a new species from the Barrier Reef (Crustacea, Amphipoda)

    NARCIS (Netherlands)

    Thomas, James Darwin; Barnard, J.L.

    1990-01-01

    A new species of Jerbarnia is described in 2 meters of depth from Lizard Island on the Great Barrier Reef. It is the first species from depths shallower than 13 m. The species differs from all but J. aquilopacifica (Japan) in the lack of major teeth on pleonites 1-3 and from the latter species in th

  14. Barcoding of ancient lake ostracods (crustacea reveals cryptic speciation with extremely low distances.

    Directory of Open Access Journals (Sweden)

    Ivana Karanovic

    Full Text Available Ostracods are drastically reduced crustaceans, with never more than eight appendages enclosed between two valves, leaving only a limited number of morphological characters for species delineation. Conservative morphology of characters used to define genera, along with high variability of characters used to define species are creating problems in applying a morphospecies concept. A high intraspecific variability in a Lake Biwa (Japan endemic, Physocypria biwaensis (Okubo, 1990, has been observed previously but was never studied in detail. Two sympatric forms, differing in pigmentation and size, suggest a presence of reproductive isolation. The aim of this study is to employ molecular and morphometric tools to aid in species delineation within P. biwaensis complex and reconstruct their phylogenetic relationships. A fragment of the mtCOI gene was amplified from 30 specimens, and an additional 37 specimens were studied for morphological characters. Resulting phylogenies showed that each morphologically distinct form is associated with a distinct phylogenetic group based on mtDNA. The average pairwise distance is very low (5%, indicating a recent divergence time. I speculate that there is a possibility that one of them originated in the lake, while the other probably colonized it afterwards. This seems to be supported with an apparent niche partitioning at different depths. In spite of the fact that traditionally used sexual characters are highly variable in these two species, the morphometric analysis of shell and soft part related characters clearly delineates them and suggests that such characters may be useful for future detection of seemingly cryptic ostracod species.

  15. Records of Hippa strigillata (Stimpson, 1860 (Crustacea: Decapoda: Hippidae in the SE Gulf of California, Mexico

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    Daniela Ríos-Elósegui

    Full Text Available This paper presents details regarding the collections and records of H. strigillata in the Bay of Mazatlán, SE Gulf of California, Mexico. Samples of H. strigillata were obtained in this bay and suroundings area during different periods and deposited in the collection of UNAM, Mazatlán. Morphometric data, distribution, biological and ecological data were furnished.

  16. Biodiversity and Biogeography of Chthamalid Barnacles from the North-Eastern Pacific (Crustacea Cirripedia).

    Science.gov (United States)

    Chan, Benny K K; Chen, H-N; Dando, P R; Southward, A J; Southward, E C

    2016-01-01

    The biogeography and ecology of the species of Chthamalus present on the west coast of America are described, using data from 51 localities from Alaska to Panama, together with their zonation on the shore with respect to that of other barnacles. The species present were C. dalli, Pilsbry 1916, C. fissus, Darwin, 1854, C. anisopoma Pilsbry 1916 and four species in the C. panamensis complex. The latter are C. panamensis Pilsbry, 1916, C. hedgecocki, Pitombo & Burton, 2007, C. alani nom. nov. (formerly C. southwardorum Pitombo & Burton, 2007) and C. newmani sp. nov.). These four species were initially separated by enzyme electrophoresis. They could only be partially separated by DNA bar coding but may be separated using morphological characters.

  17. The fate of Lernaeocera branchialis (L.) (Crustacea; Copepoda) in Atlantic cod, Gadus morhua L.

    Science.gov (United States)

    Baily, J E; Smith, J L; Wootten, R; Sommerville, C

    2011-02-01

    Lernaeocera branchialis, a copepod crustacean parasite of gadoids, represents a potential threat to both wild and farmed cod, Gadus morhua. The pathological changes associated with the early stages of experimental infection have previously been reported in detail, and this article describes the lesions associated with later chronic stages of experimental infection. Chronic infection is characterised by extravascular granuloma formation and proliferation of fibrovascular tissue around intact and fragmented, degenerate parasites within both the gill arch and cardiac region. The majority of parasite granulomas are located within connective tissues of the gill arch or pericardium; however, low numbers are present within the wall of large vessels. The intraluminal parasites and thrombi of early stage infection are largely absent in these later lesions. We propose that organisation and incorporation of the parasite thrombus into the vessel wall with subsequent granuloma formation and extrusion into the surrounding connective tissue leads to the elimination of the parasite from the vascular system. Thus, rather than being a negative consequence of infection thrombosis is protective, allowing the host to survive the substantial initial vascular insult.

  18. Using length-frequency data to elucidate the population dynamics of Argulus foliaceus (Crustacea: Branchiura).

    Science.gov (United States)

    Taylor, N G H; Wootten, R; Sommerville, C

    2009-08-01

    This study uses a novel method for discriminating cohorts and investigating the population dynamics of the parasitic crustacean, Argulus foliaceus. Analysis of parasite length-frequency data was carried out in order to elucidate the timings and drivers behind the parasite's life cycle. Up to 6 cohorts of the parasite emerge through the course of 1 year in still-water trout fisheries in England. Recruitment ceases over the winter months; however, 3 cohorts of the parasite over-winter, 2 as eggs and 1 as a hatched stage. The technique, when used in conjunction with temperature data, also allowed for the reliable prediction of growth rates and provided estimates of egg incubation times and the length of hatching periods. These data showed that growth rates increased exponentially between the observed temperatures of 4 to 22 degrees C. The method allowed for the time taken from hatching to egg laying under field conditions to be predicted and produced estimates that were validated against independent laboratory studies on the growth of the parasite.

  19. Dry season distribution of land crabs, Gecarcinus quadratus (Crustacea: Gecarcinidae), in Corcovado National Park, Costa Rica.

    Science.gov (United States)

    Griffiths, Megan E; Mohammad, Basma A; Vega, Andres

    2007-03-01

    The land crab Gecarcinus quadratus is an engineering species that controls nutrient cycling in tropical forests. Factors regulating their coastal distribution are not fully understood. We quantified land crab distribution during the dry season at Sirena Field Station in Corcovado National Park, Costa Rica, and found that land crab burrow density decreases with increasing distance from the ocean. Leaf litter depth and tree seedling density are negatively correlated with land crab burrow density. Burrows are strongly associated with sand substrate and burrow density is comparatively low in clay substrate. Results suggest that G. quadratus is limited to a narrow coastal zone with sand substrate, and this distribution could have profound effects on plant community structure.

  20. Primer registro de Ligia baudiniana (Crustacea: Isopoda: Oniscidea) para el Caribe colombiano..

    OpenAIRE

    López Orozco, Carlos Mario; Bermúdez, Adriana; Navas S., Gabriel R

    2014-01-01

    The isopod Ligia baudiniana is reported for the first time from the Caribbean coast of Colombia. Specimens of this species were collected on a rocky, intertidal substrate on the beaches of Marbella, Cartagena de Indias. A diagnosis is included along with illustrations of main taxonomic characters.

  1. Ensayo de diferentes lecitinas en la dieta de juveniles de Penaeus vannamei (Crustacea: Decapoda

    Directory of Open Access Journals (Sweden)

    Ana Denisse Re-Araujo

    2003-09-01

    Full Text Available Para comparar diferentes niveles y calidades de lecitina se hizo un bioensayo nutricional con dietas isoenergéticas; para medir el crecimiento, la tasa de conversión alimenticia y sobrevivencia de juveniles de P. vannamei (290 mg ± 0.02. Las lecitinas experimentales fueron de calamar, lecitina liquida de soya (7%, lecitina desaceitada de soya (3.48% en combinación con aceite de pescado o lípidos neutros de calamar, en una formula parcialmente desaceitada. Las cinco dietas fueron administradas ad libitum con cuatro replicas (estanques de 15 camarones cada uno (5 x 4 x 15, durante 28 días. La mayor ganancia en peso fue (191% y FCR (1.69±0.041 fueron obtenidos con la dieta que contenía 7% de lecitina cruda de soya como única fuente de lípidos, seguida por la dieta que contenía 3.94% de lecitina desaceitada y 2.24% de aceite Menhaiden (172% y 2.03±0.054 respectivamente. Como se esperaba los resultados menos propicios fueron con la dieta que no contenía lecitina (121% y 2.42±0.129. La lecitina cruda de soya, cubrió los requerimientos de fosfolípidos y de lípidos neutrales, tanto como la dieta con lecitina desaceitada de soya con aceite de pescado o aceite de calamarThe effect of different lecithin sources and presentations on growth, food conversion ratio and survival of P. vannamei (290 mg ± 0.02 was studied. The bioassay was designed in order to compare different dietary levels and different quality of lecithin. Squid lecithin, crude soybean (7%, deoiled soybean lecithin (3.48% in combination with fish oil or squid neutral lipids, in a partially dilapidate formula. The isoenergetic diets were fed ad libitum to four replicate groups (tanks of 15 shrimps each (5 x 4 x 15, during 28 days. The result of the bioassay with the partially dilapidate formulas was; the best growth rate (191% and FCR (1.69±0.041 were obtained with the diet containing 7% of soybean crude lecithin as the unique lipid source. Followed by the diet countering 3.94% deoiled lecithin and 2.42% Menhaden oil (172% and 2.03±0.054 respectively. As expected, the worst results were obtained without the dietary lecithin 121% and 2.42±0.129. Crude soybean lecithin alone covered the phospholipid and neutral lipids requirements as well as the combination of deoiled soybean lecithin with fish or squid oil

  2. Bornean freshwater crabs of the genus Arachnothelphusa gen. nov. (Crustacea: Decapoda: Brachyura: Gecarcinucidae)

    NARCIS (Netherlands)

    Ng, P.K.L.

    1991-01-01

    A new genus, Arachnothelphusa gen. nov., is established for five species of Bornean freshwater crabs (Gecarcinucidae) previously placed in Thelphusula Bott, 1969. One species from Sabah, A. terrapes, is here described as new. The genus is characterised by its long ambulatory legs, shape of the carap

  3. Spelaeomysis cochinensis, a new mysid (Crustacea: Mysidacea) from a prawn culture field in Cochin, India

    Digital Repository Service at National Institute of Oceanography (India)

    Panampunnayil, S.U.; Viswakumar, M.

    to S. servatus Fage (1925) known from Zanzibar and S. cardisomae Bowman (1973) known from Mexico in many of its characters, notably in having separate eye- plates with visual elements and in the apical arma- ture of the telson. But S. cochinensis...

  4. Growth of hatchery raised banana shrimp Penaeus merguiensis (de Man) (Crustacea: Decapoda) juveniles under different salinity

    Digital Repository Service at National Institute of Oceanography (India)

    Saldanha, C.M.; Achuthankutty, C.T.

    relationships of estuaries to the fisheries of the Gulf of Mexico, in Estuaries, edited by Lauff G H (Amer Ass Adv Sci Publ, Washington D C) 1967, pp. 621-638. 3 Mair J McD, Salinity and water-type preference of four species of postlarval shrimp (Penaeus) from... west Mexico, J Exp Mar Biol Ecol, 45(1980)69-82. 4 Achuthankutty C T & Parulekar A H, Biology of commercially important penaeid prawns of Goa waters, Indian J Mar Sci, 15 (1986)171-173. 5 Achuthankutty C T & Parulekar A H, Distribution of penaeid...

  5. The new species of Mysidacea (Crustacea), Anchialina labatus and Gastrosaccus sarae, from south west Australia

    Digital Repository Service at National Institute of Oceanography (India)

    Panampunnayil, S.U.

    Descriptions of two new sepcies Anchialina labatus and Gastrosaccus sarae, are give. A. lobatus is distinguished from the other species of the genus by the presence of a hairy lobe on the first segment of the antennule, by the modified setae...

  6. Mysids (Crustacea) from the salt pans of Mumbai, India, with a description of a new species

    Digital Repository Service at National Institute of Oceanography (India)

    Biju, A.; Panampunnayil, S.U.

    The taxonomy, distribution and ecology of mysids collected from the salt pans of Mumbai, India, were studied. Two mysid species are represented, of which one species, Indomysis nybini, is described as new to science. The new species is distinguished...

  7. Four new species of the genus Rhopalophthalmus (Mysidacea: Crustacea) from the northwest coast of India

    Digital Repository Service at National Institute of Oceanography (India)

    Panampunnayil, S.U.; Biju, A.

    thoracic endopods, and the vestigial endopod of the eighth thoracic limb of both sexes is longer than the basal plate of the exopod. In R. tattersallae, one of the long spines on the antennal sympod is barbed; thoracic endopods three to seven have only... the inner pair. Rhopalophthalmus kempi O.Tattersall, 1957 is the only other species of the genus in which the endopod of the eighth thoracic limb in both sexes is longer than the basal segment of the exopod. But R. kempi differs from the new species...

  8. Description of two new apseudomorphan Tanaidacea (Crustacea: Malacostraca: Peracarida) from the Kochi Backwaters, India

    Digital Repository Service at National Institute of Oceanography (India)

    PandiyaRajan, R.S.; Jyothibabu, R.; Arunpandi, N.; Biju, A.

    antennular flagellum longer than outer flagellum in both sexes. Antenna composed of five peduncular articles. Mandible with triarticulated palp. Maxilliped palp four articled. Absence of spines on outer edge of article 2 of maxilliped palp. Ischium... of pereopod 2 bearing a sternal spine. Female cheliped stout, but in male it is thin. Cutting edge of fixed finger of cheliped bearing seven conical teeth distally in both sexes. Uropodal exopod with 10-11 articles and exopod with 38-40 articles. Materials...

  9. A new genus and species of Heteromysini (Crustacea- Mysidacea) from the backwater of Kochi (Kerala, India)

    Digital Repository Service at National Institute of Oceanography (India)

    Panampunnayil, S.U.; Buju, A.

    ; pleopods rudimentary in both sexes; telson entire, apex with two pairs of spines, outer pair longer than inner. Uropods without spines. Females with marsupium formed of two pairs of lamellae. Figure 1. Location of station (arrowhead indicates the occurrence... pleopods rudimentary in both sexes, telson with or without apical cleft, and third thoracic endopod sometimes enlarged and robust. The new genus Kochimysis clearly belongs to the tribe Heteromysini based on these characters. The tribe at present contains 10...

  10. Descriptions of five new species of Haplostylus (Mysidaceae crustacea) from South West Australia

    Digital Repository Service at National Institute of Oceanography (India)

    Panampunnayil, S.U.

    and are well spaced. The interesting sexual dimorphism of the telson is another distinguishing character of the present species. In H.flagelliforma, the telson is similar in both sexes, while in the present species the females always have a greater number... of this species is easily distinguished from the same sex of the other related species by the armature of the telson and inner uropod. Etymology The specific name is derived from the many spines on the inner uropod. 1221 S.U.Pan ampunnayll Fig. 13. Haplostylus...

  11. Arctocypris fuhrmanni, n. gen., n. sp. (Crustacea, Ostracoda, Eucypridinae) from Spitsbergen (Norway).

    Science.gov (United States)

    Petkovski, Trajan K; Scharf, Burkhard; Keyser, Dietmar

    2016-01-14

    Material from Spitsbergen (Norway) collected by Spitzenberger (1996) was reinvestigated. A new genus Arctocypris and a new species Arctocypris. fuhrmanni n. gen. n. sp. are described in the present paper. A key to the genera of the subfamily Eucypridinae is provided. At the moment Arctocypris n. gen. comprises four species: Arctocypris arctica (Olofsson, 1918) comb. nov.; A. dulcifons (Diebel & Pietrzeniuk, 1969) comb. nov.; A. foveata (Delorme, 1968) comb. nov. and Arctocypris fuhrmanni n. gen., n. sp.

  12. Debroyerella gen. nov. and Ulladulla gen. nov., two new lysianassoid genera (Crustacea, Amphipoda, Lysianassoidea).

    Science.gov (United States)

    Lowry, J K; Kilgallen, N M

    2015-02-19

    Two new genera and a new species of lysianassoid amphipods are described. Debroyerella gen. nov. is described for three Antarctic species previously assigned to the genus Cheirimedon. Ulladulla gen. nov. is described to accommodate the new species U. selje, from Australian waters. Diagnostic descriptions are given for the genera and all species are described in full.

  13. On the occurrence of the tropical caprellid Paracaprella pusilla Mayer, 1890 (Crustacea: Amphipoda in Europe

    Directory of Open Access Journals (Sweden)

    M. ROS

    2012-12-01

    Full Text Available Paracaprella pusilla MAYER, 1980 is a tropical caprellid amphipod species first described from Brasil and very common along the Atlantic coast of Central America. Since its original description, P. pusilla has been found at numerous widespread locations in tropical and subtropical seas around the world, primarily associated with fouling communities in harbours. An established population of P. pusilla was recently found in Cádiz, southern Spain, which is both the northernmost collection and first record of this species in European coastal waters. Ship fouling is the most probable vector for its introduction. The species was always found associated with the native hydroid Eudendrium racemosum (CAVOLINI, 1785 and appeared to display a mutualistic relationship with this host.

  14. Distribution and abundance of mysid shrimps (Crustacea: Mysidacea) in the Northern Indian Ocean.

    Digital Repository Service at National Institute of Oceanography (India)

    Biju, A.; Jagadeesan, L.; Panampunnayil, S.U.

    in their distribution to surface waters only (Table III). In the 500–1000m depth stratum only two species, Boreomysis plebeja Hansen, 1910 and Gibbery- throps acanthura (Illig, 1906) were observed (Table III). Most of the species showed spatial and temporal variations.... typica orientalis were found in one depth stratum (surface; Table III) and P. inscita distribution was in both the surface and TT–BT layers. The distribution of P. pusilla was different from the other three species, occurring at higher densities from...

  15. Mysids (Crustacea) from the Exclusive Economic Zone of India with description of a new species

    Digital Repository Service at National Institute of Oceanography (India)

    Biju, A.; Panampunnayil, S.U.

    (IOBC), National Institute of Oceanography (NIO), Kochi. Materials and methods The materials for the present study are based on samples collected in the Arabian Sea, Bay of Bengal and the Andaman Sea (Figure 1) during different cruises... & Tattersall Genus Boreomysis G.O. Sars Boreomysis plebeja Hansen, 1910 (Figure 2A, B) Boreomysis plebeja Hansen 1910: 24–25, plate 2, Figure 2a–d; Illig 1930: 414, 560; O. Tattersall 1955: 68, 74, Figure 11 A; Ii 1964: 35, Figures 5–6. Materials...

  16. Habitat architecture influencing microcrustaceans composition: a case study on freshwater Cladocera (Crustacea Branchiopoda).

    Science.gov (United States)

    Debastiani-Júnior, J R; Elmoor-Loureiro, L M A; Nogueira, M G

    2016-02-01

    Environmental complexity is considered a key factor for diversity enhancement in aquatic ecosystems. Macrophyte stands are a major contributor for this complexity due to their differential architectures. Nevertheless, the influence of distinct aquatic habitat architectures (with different types of macrophytes or without them) on microcrustaceans' taxa composition, usually found in macrophyte colonized water bodies, is underexplored in limnological studies. The main objective of this study was to analyze this influence by comparing the Cladocera composition among four habitat architectures: (1) fluctuant macrophytes, (2) rooted emergent macrophytes, (3) submerged macrophytes and (4) the limnetic zone of oxbow lakes associated to a large subtropical reservoir. Wide compositional variation was observed. Fluctuant macrophytes exhibited the richest Cladocera assemblage, dominated by Chydoridae. Submerged and rooted emergent macrophytes had the most similar assemblages between them. The most distinctive fauna was found in the limnetic zone, dominated by Bosminidae. Probable differences in resource availability in each sampled habitat architecture are considered as the driving factor for the Cladocera composition variation. We concluded that for a complete inventory of a given local fauna, it is imperative to take into account the aquatic habitat architecture, including macrophyte stands, in the data sampling design.

  17. Habitat architecture influencing microcrustaceans composition: a case study on freshwater Cladocera (Crustacea Branchiopoda

    Directory of Open Access Journals (Sweden)

    J. R. Debastiani-Júnior

    Full Text Available Abstract Environmental complexity is considered a key factor for diversity enhancement in aquatic ecosystems. Macrophyte stands are a major contributor for this complexity due to their differential architectures. Nevertheless, the influence of distinct aquatic habitat architectures (with different types of macrophytes or without them on microcrustaceans’ taxa composition, usually found in macrophyte colonized water bodies, is underexplored in limnological studies. The main objective of this study was to analyze this influence by comparing the Cladocera composition among four habitat architectures: (1 fluctuant macrophytes, (2 rooted emergent macrophytes, (3 submerged macrophytes and (4 the limnetic zone of oxbow lakes associated to a large subtropical reservoir. Wide compositional variation was observed. Fluctuant macrophytes exhibited the richest Cladocera assemblage, dominated by Chydoridae. Submerged and rooted emergent macrophytes had the most similar assemblages between them. The most distinctive fauna was found in the limnetic zone, dominated by Bosminidae. Probable differences in resource availability in each sampled habitat architecture are considered as the driving factor for the Cladocera composition variation. We concluded that for a complete inventory of a given local fauna, it is imperative to take into account the aquatic habitat architecture, including macrophyte stands, in the data sampling design.

  18. Les processidae (Crustacea Decapoda Natantia) des eaux Européennes

    NARCIS (Netherlands)

    Nouvel, H.; Holthuis, L.B.

    1957-01-01

    PRÉ FACE Au cours d'études sur la biologie des Processa des mers européennes (1937-1944), le premier auteur fut frappé par les différences singulières que présentaient des spécimens qui, en accord avec l'opinion courante, devaient se rapporter à une même espèce. I1 résolut d'approfondir le côté syst

  19. Three new sympatric species of Remipedia (Crustacea) from Great Exuma Island, Bahamas Islands

    NARCIS (Netherlands)

    Koenemann, Stefan; Iliffe, Thomas M.; Ham, van der Joris

    2003-01-01

    Three new sympatric species of remipede crustaceans, Speleonectes tanumekes, Speleonectes parabenjamini and Speleonectes minnsi, are described from an anchihaline cave on Great Exuma Island in the central Bahamas. Speleonectes tanumekes is a comparatively long and slender species distinguished by

  20. First Record of Cleantioides planicauda (Crustacea: Isopoda: Holognathidae from South Korea

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    Gi-Sik Min

    2014-01-01

    Full Text Available Cleantioides planicauda (Benedict, 1899 has previously been recorded in China and Japan. In the present study, to our knowledge, we report for the first time the occurrence of this species in South Korea. Here, we provide detailed descriptions and illustrations of the diagnostic characteristics of C. planicauda. Further, for the first time, we determined the partial sequence of mitochondrial cytochrome c oxidase subunit 1 (CO1 gene of C. planicauda for molecular characteristic. Additionally, we provide a key to the Korean species and distribution of the genus Cleantioides. As a result of this study, four species of the genus Cleantioides, including C. planicauda, have now been recorded in South Korea.

  1. Growth curve of Atlantoscia floridana (van Name (Crustacea, Isopoda, Philosciidae from a Brazilian Restinga Forest

    Directory of Open Access Journals (Sweden)

    Paula Beatriz Araujo

    2004-03-01

    Full Text Available The terrestrial isopod Atlantoscia floridana (van Name, 1940 occurs from the U.S.A. (Florida to Brazil and Argentina. In the southernmost Brazilian State, Rio Grande do Sul, the species is recorded in many localities, in urban and in non-urban areas. The growth curve of Atlantoscia floridana based on field data is presented. The specimens were sampled from April, 2000 to October, 2001 at the Reserva Biológica do Lami (RBL, Rio Grande do Sul. Captured individuals were sexed and had their cephalothorax width measured, with the data analyzed with von Bertalanffy's model. The growth curves for males and females are described, respectively, by the equations: Wt = 1.303 [1 - e-0.00941 (t + 50.37] and Wt = 1.682 [1 - e-0.00575 (t + 59.13]. The curves showed differential growth between sexes, where females reach a higher Wµ with a slower growth rate. Based on the growth curves it was also possible to estimate life expectancy for males and females.O isópodo terrestre Atlantoscia floridana (van Name, 1940 ocorre desde os Estados Unidos (Flórida até o Brasil e Argentina. No Rio Grande do Sul a espécie é registrada em muitas localidades, em áreas urbanas e não-urbanas. Este trabalho apresenta a curva de crescimento de Atlantoscia floridana, baseada em dados de campo. Os espécimes foram amostrados desde abril, 2000 a outubro, 2001 na Reserva Biológica do Lami (RBL, Rio Grande do Sul. Os indivíduos capturados foram sexados e tiveram o cefalotórax medido. Os dados foram analisados utilizando-se o modelo de von Bertalanffy. A curva de crescimento para machos e fêmeas são descritas, respectivamente, pelas equações Wt = 1.303 [1 - e-0.00941 (t + 50.37] e Wt = 1.682 [1 - e -0.00575 (t + 59.13]. As curvas mostraram crescimento diferencial entre os sexos, onde as fêmeas atingem o maior Wµ com uma taxa de crescimento menor. Com base nas curvas de crescimento também foi possível estimar a expectativa de vida para machos e fêmeas.

  2. Dead shrimp blues: a global assessment of extinction risk in freshwater shrimps (Crustacea: Decapoda: Caridea.

    Directory of Open Access Journals (Sweden)

    Sammy De Grave

    Full Text Available We present the first global assessment of extinction risk for a major group of freshwater invertebrates, caridean shrimps. The risk of extinction for all 763 species was assessed using the IUCN Red List criteria that include geographic ranges, habitats, ecology and past and present threats. The Indo-Malayan region holds over half of global species diversity, with a peak in Indo-China and southern China. Shrimps primarily inhabit flowing water; however, a significant subterranean component is present, which is more threatened than the surface fauna. Two species are extinct with a further 10 possibly extinct, and almost one third of species are either threatened or Near Threatened (NT. Threats to freshwater shrimps include agricultural and urban pollution impact over two-thirds of threatened and NT species. Invasive species and climate change have the greatest overall impact of all threats (based on combined timing, scope and severity of threats.

  3. A new species of crinoid-associated Periclimenes from Honduras (Crustacea: Decapoda: Palaemonidae).

    Science.gov (United States)

    De Grave, Sammy

    2014-05-02

    A new species of crinoid associated Periclimenes, P. rincewindi sp. nov. is described from the Bay Islands (Honduras) in the Caribbean. The species associates with the swimming crinoid, Analcidometra armata and displays a unique colour pattern. Morphologically, the new species is closely related to the other known crinoid associates in the Caribbean, specifically Periclimenes crinoidalis, from which it can be distinguished by a suite of relatively minor morphological features.

  4. Description, systematics and ecology of a new tanaidacean (Crustacea, Peracarida) species from mediterranean fish farms

    Science.gov (United States)

    Esquete, P.; Fernandez-Gonzalez, V.

    2017-01-01

    An undescribed species of tanaidacean belonging to the genus Hexapleomera, tribe Pancolini, Hexapleomera bultidactyla sp. nov. was found in fouling community samples from off-coast fish farms cages in the western Mediterranean Sea. The species can be distinguished from other Hexapleomera species by the presence of a ventral apophysis on the dactylus of the chela in males. Other diagnostic characters (in combination) include a male antennule with five aesthetascs, the female with three, the maxillule palp with four terminal setae and maxilliped basis and coxa each with two setae; the male fixed finger with four ventral setae and proximal apophysis, the female chela fixed finger with a proximal triangular apophysis, an apophysis on the coxa of pereopod 1, a pleopod 3 basis with three outer setae, and an uropod of four segments. Although several substrata were investigated, the species was most abundant where the turf formed by Ceramiaceae algae and the hydroid Aglaophenia sp. was dominant. An updated identification key to all the species of Hexapleomera is provided.

  5. Studies on the planktonic Decapoda and Stomatopoda (Crustacea) from the western Bay of Bengal

    Digital Repository Service at National Institute of Oceanography (India)

    Paulinose, V.T.; Nair, V.R.; Goswami, S.C.

    Abundance and distribution of decapods and stomatopods were studied, based on 90 samples collected from the western Bay of Bengal (Lat. 09 degrees 58' and 20 degrees 50'N and long. 80 degrees 00'E) between 24 August and 2 October, 1976. The decapod...

  6. A new species of seagrass-boring Limnoria (Limnoriidae, Isopoda, Crustacea) from Japan.

    Science.gov (United States)

    Yoshino, Hiroki; Watabe, Hikari; Ohsawa, Takeshi A

    2017-02-15

    The marine seagrass-boring isopod, Limnoria rhombipunctata sp. nov. (Limnoriidae) is described from the rhizome of Phyllospadix iwatensis seagrass, in shallow coastal waters off Chiba Prefecture, Japan. L. rhombipunctata sp. nov. is distinguished from other Limnoria species by the unique carinae of pleonite 5 and pleotelson, two branched lacinia mobilis of the right mandible, 3 flagellar articles of antenna 1, and triangular epipod of the maxilliped. Specimens of L. magadanensis, a species similar to L. rhombipunctata sp. nov., are re-examined and compared with L. rhombipunctata sp. nov.

  7. Occurrence of Lophogaster spinosus Ortmann, 1906 (Crustacea, Lophogastrida in the Gulf of Cadiz (NE Atlantic

    Directory of Open Access Journals (Sweden)

    Abelló, P.

    2011-11-01

    Full Text Available The occurrence of the lophogastrid crustacean Lophogaster spinosus is reported for the Gulf of Cadiz waters, in the North-East Atlantic. This is the first report of the species for the Iberian Atlantic region. Samples were collected by demersal trawling during a fisheries research survey performed in March 2008. A total of four specimens were collected at three sampling sites. Depths of occurrence ranged between 363 and 548 m.

  8. The complete mitogenome of the Norway lobster Nephrops norvegicus (Linnaeus, 1758) (Crustacea: Decapoda: Nephropidae).

    Science.gov (United States)

    Gan, Han Ming; Tan, Mun Hua; Gan, Huan You; Lee, Yin Peng; Austin, Christopher M

    2016-09-01

    The clawed lobster Nephrops norvegicus is an important commercial species in European waters. We have sequenced the complete mitochondrial genome of the species from a partial genome scan using Next-Gen sequencing. The N. norvegicus has a mitogenome of 16,132 base pairs (71.22% A+ T content) comprising 13 protein-coding genes, 2 ribosomal subunit genes, 21 transfer RNAs, and a putative 1259 bp non-coding AT-rich region. This mitogenome is the second fully characterized for the family Nephropidae and the first for the genus Nephrops. The mitogenome gene order is identical to the Maine lobster, Homarus americanus with the exception of the possible loss of the trnI gene.

  9. The complete mitochondrial genome of the Violet-spotted reef lobster Enoplometopus debelius (Crustacea, Astacidea, Enoplometopidae).

    Science.gov (United States)

    Ahn, Dong-Ha; Min, Gi-Sik; Park, Joong-Ki; Kim, Sanghee

    2016-05-01

    The violet-spotted reef lobster Enoplometopus debelius Holthuis, 1983 (Decapoda, Astacidea, Enoplometopidae) is found in the tropical reef areas of the Indo-Pacific region, and is a highly prized and very popular species in the aquarium trade industry. The complete mitochondrial genome of E. debelius has 15,641 base pairs consisting of 13 protein-coding genes, 22 transfer RNAs, 2 ribosomal RNAs, and a control region of 746 bp. The base composition of E. debelius is 36.4% A, 35.3% T, 18.1% C, 10.3% G, and the species has an AT content of 71.7%. The E. debelius mitogenome was found to have a gene arrangement and transcriptional polarity identical to that of the Homarus americanus mitogenome, a representative of the arthropod ground pattern. Here, we present the complete mitogenome sequence of E. debelius, which is the first in the superfamily Enoplometopoidea. These data will provide a useful molecular resource for the phylogenetic study of the infraorder Astacidea/order Decapoda.

  10. The complete mitochondrial genome of the Japanese fan lobster Ibacus ciliatus (Crustacea, Achelata, Scyllaridae).

    Science.gov (United States)

    Ahn, Dong-Ha; Kim, Sanghee; Park, Joong-Ki; Shin, Sook; Min, Gi-Sik

    2016-05-01

    Slipper lobsters are a unique group of decapod crustaceans; they have cylindrical or flattened bodies and belong to the family Scyllaridae. The genus Ibacus (Leach, 1815) (Achelata, Scyllaridae, Ibacinae) consists of eight recognized species to date, all of which occur in the Indo-West Pacific Ocean and are commercially important seafood species. The complete mitochondrial genome of the Japanese fan lobster Ibacus ciliatus (Von Siebold, 1824) is 15,696 bp in size and consists of 13 protein-coding genes, 22 transfer RNAs, 2 ribosomal RNAs, and a control region of 783 bp. The base composition of I. ciliatus is 35.8% A, 34.7% T, 19.0% C, and 10.5% G, with an overall AT content of 70.5%. The mitogenome of I. ciliatus was found to have gene arrangement and transcriptional polarity identical to that of the American lobster Homarus americanus, showing the pancrustacean ground pattern. Here, we present the complete mitogenome sequence of I. ciliatus; it is the first mitogenome information from the subfamily Ibacinae, and represents the second for the family Scyllaridae.

  11. Herkenning en biotoop van de West-Europese Dexaminidae (Crustacea, Amphipoda)

    NARCIS (Netherlands)

    Vader, W.

    1969-01-01

    De amphipodenfamilie Dexaminidae is in West-Europa met vier soorten vertegenwoordigd, te weten Dexamine Spinosa (Montagu), Dexamine thea Boeck, Guernea coalita (Norman) en Tritaeta gibbosa (Bate). Tot nu toe is van deze vier alleen Dexamine thea in de Nederlandse wateren aangetroffen, en wel tweemaa

  12. Morphological and histological studies on the embryonic development of the freshwater prawn, Macrobrachium rosenbergii (Crustacea, Decapoda

    Directory of Open Access Journals (Sweden)

    Madlen M. Habashy

    2012-05-01

    Full Text Available The present work was carried out to describe the embryonic changes during development of the freshwater prawn Macrobrachium rosenbergii based on some morphological and histological features. In addition the biochemical composition of eggs was investigated during the embryonic development of the studied species. Results revealed that eggs of M. rosenbergii completed their development in 20 days at 28.5 ± 0.45 °C. The present investigation showed that primordial germ cells (PGCs were detected early in the examined embryos. In 6.5 days old embryo, a cluster of PGCs occupied the dorso-medial region behind the yolky portion. In addition, the biochemical data indicated that the protein content was significantly increased, while lipid and carbohydrate contents decreased during the embryonic development. The lowest water content was found in the bright orange eggs and reached its highest level in the deep brown eggs. It was noted that the increase in the water content was correlated with the increase in the egg diameters. It was also concluded that, variations in the biochemical compositions of eggs reflected changes in their morphogenesis during the embryonic development.

  13. Grooming as a secondary behavior in the shrimp Macrobrachium rosenbergii (Crustacea, Decapoda, Caridea

    Directory of Open Access Journals (Sweden)

    Lauren VanMaurik

    2014-11-01

    Full Text Available The giant freshwater prawn, Macrobrachium rosenbergii, is a large shrimp extensively used in aquaculture whose grooming behaviors were analyzed in this study. Macrobrachium rosenbergii exhibits three unique male morphotypes that differ in their behavior, morphology and physiology: small-clawed males (SM, orange-clawed males (OC and blue-clawed males (BC. The largest and most dominant males, BC males, are predicted to have significantly different grooming behaviors compared to females and the other two male morphotypes. These BC males may be too large and bulky to efficiently groom and may dedicate more time to mating and agonistic interactions than grooming behaviors. Observations were conducted to look at the prevalence of grooming behaviors in the absence and presence of conspecifics and to determine if any differences in grooming behavior exist among the sexes and male morphotypes. Significant differences in the grooming behaviors of all individuals (females and male morphotypes were found. BC males tended to have the highest grooming time budget (percent of time spent grooming while SM males had a relatively low grooming time budget. The grooming behaviors of the male morphotypes differed, indicating while these males play distinct, separate roles in the social hierarchy, they also have different grooming priorities. The conditions in which M. rosenbergii are cultured may result in increased body fouling, which may vary, depending on the grooming efficiencies and priorities of these male morphotypes. Overall, grooming behaviors were found to be a secondary behavior which only occurred when primary behaviors such as mating, feeding or fighting were not present.

  14. Notes on Indo-West Pacific Crustacea Decapoda III to IX

    NARCIS (Netherlands)

    Holthuis, L.B.

    1995-01-01

    Seven short notes: (1) describing a new species of Macrobrachium from Madagascar, (2) synonymizing Chlorotocella leptorhynchus (Stimpson, 1860) with C. spinicaudus (H. Milne Edwards, 1837), (3) synonymizing Rhynchocinetes rugulosus Stimpson, 1860, with R. serratus (H. Milne Edwards, 1837), (4) estab

  15. Formation of the hindgut cuticular lining during embryonic development of Porcellio scaber (Crustacea, Isopoda

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    Polona Mrak

    2015-07-01

    Full Text Available The hindgut and foregut in terrestrial isopod crustaceans are ectodermal parts of the digestive system and are lined by cuticle, an apical extracellular matrix secreted by epithelial cells. Morphogenesis of the digestive system was reported in previous studies, but differentiation of the gut cuticle was not followed in detail. This study is focused on ultrastructural analyses of hindgut apical matrices and cuticle in selected intramarsupial developmental stages of the terrestrial isopod Porcellio scaber in comparison to adult animals to obtain data on the hindgut cuticular lining differentiation. Our results show that in late embryos of stages 16 and 18 the apical matrix in the hindgut consists of loose material overlaid by a thin intensely ruffled electron dense lamina facing the lumen. The ultrastructural resemblance to the embryonic epidermal matrices described in several arthropods suggests a common principle in chitinous matrix differentiation. The hindgut matrix in the prehatching embryo of stage 19 shows characteristics of the hindgut cuticle, specifically alignment to the apical epithelial surface and a prominent electron dense layer of epicuticle. In the preceding embryonic stage – stage 18 – an electron dense lamina, closely apposed to the apical cell membrane, is evident and is considered as the first epicuticle formation. In marsupial mancae the advanced features of the hindgut cuticle and epithelium are evident: a more prominent epicuticular layer, formation of cuticular spines and an extensive apical labyrinth. In comparison to the hindgut cuticle of adults, the hindgut cuticle of marsupial manca and in particular the electron dense epicuticular layer are much thinner and the difference between cuticle architecture in the anterior chamber and in the papillate region is not yet distinguishable. Differences from the hindgut cuticle in adults imply not fully developed structure and function of the hindgut cuticle in marsupial manca, possibly related also to different environments, as mancae develop in marsupial fluid. Bacteria, evenly distributed within the homogenous electron dense material in the hindgut lumen, were observed only in one specimen of early marsupial manca. The morphological features of gut cuticle renewal are evident in the late marsupial mancae, and are similar to those observed in the exoskeleton.

  16. A Study of the Morphology and Biology of Thompsonia littoralis (Crustacea: Cirripedia: Rhizocephala)

    DEFF Research Database (Denmark)

    Lützen, Jørgen; Jespersen, Åse

    1992-01-01

    the stalk. Spermatogonia are presumably injected by male cyprids into the female externa and develop into sperm within one or more vesicular spermatogenic bodies in its mantle. The eggs are laid through a single oviduct into the mantle cavity where they become fertilized and develop into cyprids...

  17. Odors influencing foraging behavior of the California spiny lobster, Panulirus interruptus, and other decapod crustacea

    Energy Technology Data Exchange (ETDEWEB)

    Zimmer-Faust, R.K.; Case, J.F.

    1982-01-01

    Trapping experiments were conducted in the More Mesa coastal area of Santa Barbara, California, 4 km east of the U.C. Santa Barbara campus. Live intact and injured prey and excised tissues were placed in traps, in containers allowing odor release but preventing contacts with entering animals. Individuals of six prey species failed to attract lobsters when alive and intact, but some became attractive once injured. Excised tissues were the most effective baits. Abalone and mackerel muscle were attractive to lobsters but relatively nonattractive to crabs, while angel shark muscle was attractive to crabs but not to lobsters. Shrimp cephalothoraces were repellant to lobsters. Naturally occurring attractant and repellent tissues are thus identified and chemosensory abilities of lobsters and sympatric crabs are demonstrated to differ. Abalone muscle increased in attractivity following 1-2 days field exposure. Molecular weights of stimulants released by both weathered and fresh abalone were < 10,000 daltons with evidence suggesting that the 1000-10,000 dalton fraction may contribute significantly to attraction. Concentrations of total primary amines released from abalone muscle failed to differ from background levels, following an initial three (0-3h) period. Primary amines thus appear not to contribute directly to captures of lobsters, since animals were usually caught greater than or equal to 7 h after baits were positioned. Amino acids were the dominant contributors to present measurements of total primary amines, suggesting that these molecules may not direct lobster foraging behavior in the present experiments. 41 references, 4 figures, 8 tables.

  18. The shallow-water Asellota (Crustacea: Isopoda from the Beagle Channel: Preliminary taxonomic and zoogeographical results

    Directory of Open Access Journals (Sweden)

    Brenda Lía Doti

    2005-12-01

    Full Text Available The shallow-water Asellota from the Beagle Channel were investigated, based on material collected at four localities in 2001-2002. A total of 3,124 asellotes were sorted, and three new species and 12 new records of distribution were reported. The Paramunnidae showed the highest species diversity and abundance (11 species and 1,463 specimens. The present research raises the number of species known from the Beagle Channel to 23; of these, 16 were previously reported from the Magellan Straits, representing 69% of similarity. Based on the present results and published data, the faunistic affinities for the shallow-water Asellota was 30% between the Magellan region and the Scotia Arc, and 26% between the Magellan region and the Antarctic Peninsula.

  19. Toxicity of selected pesticides to the groundwater copepod Parastenocaris germanica (Crustacea)

    NARCIS (Netherlands)

    Notenboom J; Boessenkool JJ; ECO

    1994-01-01

    De toxiciteit van negen verschillende bestrijdingsmiddelen of afbraakproducten voor de grondwater copepod Parstenocaris germanica is onderzocht. De onderzochte stoffen zijn geselecteerd vanwege hun potentieel gevaar voor grondwater bewonende metazoen. Niet alle experimenten lieten een duidelijke

  20. The toxicological effects of thiamethoxam on Gammarus kischineffensis (Schellenberg 1937) (Crustacea: Amphipoda).

    Science.gov (United States)

    Uğurlu, Pelin; Ünlü, Erhan; Satar, Elif İpek

    2015-03-01

    Neonicotinoids are a new group of insecticides, and little is known about their toxicity to nontarget freshwater organisms an potential effects on freshwater ecosystems. The aim of this study is to establish the acute toxicity and histopathological effects of thiamethoxam-based pesticide on the gill tissue of Gammarus kischineffensis. In this study G. kischineffensis samples were exposed to 2.5, 5, 7.5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 60, 70, 80, 90 and 100mg/l of commercial grade thiamethoxam for 96 h. The 24, 48, 72 and 96 h LC50 values were determined as 75.619, 23.505, 8.048 and 3.751 mg/l respectively. In histopathological study the individuals were exposed to 0.004, 0.04 and 0.4 mg/l thiamethoxam concentrations for 14 days. The results showed that the most common changes at all doses of thiamethoxam were vacuolization and hemostatic infiltration in the gill tissue of G. kischineffensis.

  1. A new species of Cymadusa Savigny, 1816 (Crustacea: Amphipoda: Ampithoidae from northeastern Brazil

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    Luiz F. Andrade

    Full Text Available A new species of the amphipod family Ampithoidae Stebbing, 1899 is described from the northeastern Brazilian waters. The new described taxon is grouped in the genus Cymadusa Savigny, 1816, since it presents all the diagnostic characteristics of the genus. The examined material was collected by scuba diving in the Rocas Atoll, off Rio Grande do Norte state coast, Camamu Bay and Todos os Santos Bay, Bahia state. The new species described here is close to C. filosa Savigny, 1816, type species of the genus, by presenting anterior margin of gnathopod 1 poorly setose, male gnathopod 2 densely setose, with palmar corner not defined by a spine and dactylus subequal in length to palm, being considered part of the C. filosa complex. Among the species of this complex, the one which most resembles to the new taxon is C. imbroglio Rabindranath, 1972, which is distinguished by the absence of both the trapezoid process in the palm and spine at the palmar corner in the gnathopod 2. This is the second species of the genus Cymadusa recorded from Brazilian waters.

  2. The first zoeal stage of Parthenope macrochelos (Herbst, 1790 hatched in the laboratory (Crustacea: Brachyura: Parthenopidae

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    Guillermo Guerao

    1999-03-01

    Full Text Available The first zoeal stage of the parthenopid crab Parthenope macrochelos is described and illustrated from laboratory-hatched material obtained from an ovigerous crab captured in the western Mediterranean. The first larva of P. macrochelos possesses all the characters as diagnostic of the Parthenopidae and some additional features, including a seta on the basal segment of the endopod of the maxillule and a well developed lateral spine on the telson forks. The present stage is compared with those previously described from other species of the genus Parthenope.

  3. Axially aligned organic fibers and amorphous calcium phosphate form the claws of a terrestrial isopod (Crustacea).

    Science.gov (United States)

    Vittori, Miloš; Srot, Vesna; Žagar, Kristina; Bussmann, Birgit; van Aken, Peter A; Čeh, Miran; Štrus, Jasna

    2016-08-01

    Skeletal elements that are exposed to heavy mechanical loads may provide important insights into the evolutionary solutions to mechanical challenges. We analyzed the microscopic architecture of dactylus claws in the woodlice Porcellio scaber and correlated these observations with analyses of the claws' mineral composition with energy dispersive X-ray spectrometry (EDX), electron energy loss spectroscopy (EELS) and selected area electron diffraction (SAED). Extraordinarily, amorphous calcium phosphate is the predominant mineral in the claw endocuticle. Unlike the strongly calcified exocuticle of the dactylus base, the claw exocuticle is devoid of mineral and is highly brominated. The architecture of the dactylus claw cuticle is drastically different from that of other parts of the exoskeleton. In contrast to the quasi-isotropic structure with chitin-protein fibers oriented in multiple directions, characteristic of the arthropod exoskeleton, the chitin-protein fibers and mineral components in the endocuticle of P. scaber claws are exclusively axially oriented. Taken together, these characteristics suggest that the claw cuticle is highly structurally anisotropic and fracture resistant and can be explained as adaptations to predominant axial loading of the thin, elongated claws. The nanoscale architecture of the isopod claw may inspire technological solutions in the design of durable machine elements subjected to heavy loading and wear.

  4. Brachyura (Crustacea, Decapoda associated to Schizoporella unicornis (Bryozoa, Gymnolaemata in Ubatuba bay (SP, Brazil

    Directory of Open Access Journals (Sweden)

    Fernando L. M. Mantelatto

    1998-01-01

    Full Text Available This work characterizes the composition of Brachyura from Schizoporella unicornis. The samples were collected in 1995 at Itaguá Beach, Ubatuba (SP, at three month intervals, during all seasons from January to December. The Bryozoa colonies were obtained by snorkeling at a depth of five meters in daylight. A total of 323 specimens were collected from four families (Xanthidae, Portunidae, Majidae and Grapsidae. Pachygrapsus transversus, Hexapanopeus schimitti, and Menippe nodifrons occurred in all seasons. The highest and lowest number of individuals occurred during the spring and autumn, respectively. Xanthidae exhibited the highest density during the summer, autumn, and spring, while Grapsidae exhibited the highest density in winter. It was noted the presence of Charibdis hellerii, an portunid from Indo-Pacific ocean. The diversity of species obtained, in addition to an accentuated number of immature and ovigerous females specimens, suggested that Schizoporella colonies were a place of reproduction and development.Este trabalho caracterizou a composição dos braquiúros em Schizoporella unicornis. As amostras foram coletadas na Praia do Itaguá, Ubatuba (SP, em intervalos de três meses, durante as estações climáticas de Janeiro a Dezembro/1995. As colônias de briozoários foram obtidas por mergulho livre, coletadas pela manhã. Um total de 323 espécimes foram coletados dentro de quatro famílias (Xanthidae, Portunidae, Majidae e Grapsidae. Pachygrapsus transversus, Hexapanopeus schimitti e Menippe nodifrons ocorreram em todas as estações. O maior e o menor número de indivíduos foram registrados na primavera e no outono, respectivamente. Xanthidae exibiu maior densidade no verão, outono e primavera, enquanto Grapsidae foi no inverno. Registrou-se a ocorrência de Charibdis hellerii, espécie originária do Indo-Pacífico. A diversidade de espécies obtida, juntamente com o acentuado número de indivíduos imaturos e fêmeas ovígeras, constituem indícios de que colônias de Schizoporella constituem um local de reprodução e desenvolvimento para estes crustáceos

  5. Behavioural responses of Gammarus pulex (Crustacea, Amphipoda) to low concentrations of pharmaceuticals

    NARCIS (Netherlands)

    Lange, de H.J.; Noordoven, W.; Murk, A.J.; Lürling, M.F.L.L.W.; Peeters, E.T.H.M.

    2006-01-01

    The continuous discharge of pharmaceuticals and personal care products into the environment results in a chronic exposure of aquatic organisms to these substances and their metabolites. As concentrations in surface waters are in the ng/L range, and sometimes in the low microg/L range, they are not l

  6. On two species of Archipelothelphusa Bott, 1969 (Crustacea: Decapoda: Brachyura: Sundathelphusidae) from Luzon, Philippines

    NARCIS (Netherlands)

    Ng, P.K.L.

    1991-01-01

    The taxonomic problems concerning freshwater crabs of the genus Archipelothelphusa Bott, 1969 (Gecarcinucoidea: Sundathelphusidae) are discussed. The identity of Para-Bary-thelphusa grapsoides subsp. longipes Balss, 1937, is clarified, and a new species, A. celer spec. nov. is described from Luzon,

  7. Nuclear mitochondrial pseudogenes in Austinograea alayseae hydrothermal vent crabs (Crustacea: Bythograeidae): effects on DNA barcoding.

    Science.gov (United States)

    Kim, Se-Joo; Lee, Kyeong Yong; Ju, Se-Jong

    2013-09-01

    Members of the brachyuran crab family, Bythograeidae, are among the most abundant and common crabs in vent fields. However, their identification based on morphological characteristics often leads to incorrect species recognition due to a lack of taxonomic factors and the existence of sibling (or cryptic) species. For these reasons, we used DNA barcoding for vent crabs using mitochondrial cytochrome c oxidase subunit 1 (CO1). However, several nuclear mitochondrial pseudogenes (Numts) were amplified from Austinograea alayseae Guinot, 1990, using universal primers (Folmer primers). The Numts were characterized in six haplotypes, with 13.58-14.11% sequence divergence from A. alayseae, a higher nonsynonymous substitution ratio than true CO1, and the formation of an independent clade in bythograeids. In a neighbour-joining tree, the origin of the Numts would be expected to incorporate into the nucleus at an ancestral node of Austinograea, and they mutated more slowly in the nucleus than CO1 in the mitochondria. This evolutionary process may have resulted in the higher binding affinity of Numts for the Folmer primers than CO1. In the present study, we performed long PCR for the amplification of CO1 in A. alayseae. We also present evidence that Numts can introduce serious ambiguity into DNA barcoding, including overestimating the number of species in bythograeids. These results may help in conducting taxonomic studies using mitochondrial genes from organisms living in hydrothermal vent fields.

  8. Leucosiid crabs (Crustacea: Decapoda: Brachyura) from Taiwan, with three new records.

    Science.gov (United States)

    Shih, Yi-Jia; Ho, Ping-Ho; Chan, Tin-Yam

    2015-12-01

    Four leucosiid species from Taiwan are presented. Ebalia nudipes Sakai, 1963, with its male first gonopod figured for the first time. Galilia petricola Komai & Tsuchida, 2014, is recorded on the basis of a larger specimen, and distinguishing features with its only congener, G. narusei Ng & Richer de Forges, 2007, reappraised. Nursia rhomboidalis (Miers, 1879), previously known only from Japan, Korea, and mainland China, is also recorded from Taiwan. Myra fugax (Fabricius, 1798) is now formally recorded from Taiwan, and female characters identified to help separate the three known Taiwanese species of Myra.

  9. Eight new species of the genus Sinopotamon from Jiangxi Province, China (Crustacea, Decapoda, Brachyura, Potamidae)

    NARCIS (Netherlands)

    Ai-Yun, Dai; Xian-Min, Zhou; Wei-Dong, Peng

    1995-01-01

    Fifteen species of freshwater crabs belonging to the genus Sinopotamon are recorded from Jiangxi Province, S.E. China. Eight species are new to science and these are described: S. xiushuiense, S. jiujiangense, S. wanzaiense, S. anyuanense, S. siguqiaoense, S. linhuanense, S. yushanense and S ninggan

  10. Evolutionary history of true crabs (Crustacea: Decapoda: Brachyura) and the origin of freshwater crabs.

    Science.gov (United States)

    Tsang, Ling Ming; Schubart, Christoph D; Ahyong, Shane T; Lai, Joelle C Y; Au, Eugene Y C; Chan, Tin-Yam; Ng, Peter K L; Chu, Ka Hou

    2014-05-01

    Crabs of the infra-order Brachyura are one of the most diverse groups of crustaceans with approximately 7,000 described species in 98 families, occurring in marine, freshwater, and terrestrial habitats. The relationships among the brachyuran families are poorly understood due to the high morphological complexity of the group. Here, we reconstruct the most comprehensive phylogeny of Brachyura to date using sequence data of six nuclear protein-coding genes and two mitochondrial rRNA genes from more than 140 species belonging to 58 families. The gene tree confirms that the "Podotremata," are paraphyletic. Within the monophyletic Eubrachyura, the reciprocal monophyly of the two subsections, Heterotremata and Thoracotremata, is supported. Monophyly of many superfamilies, however, is not recovered, indicating the prevalence of morphological convergence and the need for further taxonomic studies. Freshwater crabs were derived early in the evolution of Eubrachyura and are shown to have at least two independent origins. Bayesian relaxed molecular methods estimate that freshwater crabs separated from their closest marine sister taxa ~135 Ma, that is, after the break up of Pangaea (∼200 Ma) and that a Gondwanan origin of these freshwater representatives is untenable. Most extant families and superfamilies arose during the late Cretaceous and early Tertiary.

  11. The male copulatory system of European pea crabs (crustacea, brachyura, pinnotheridae).

    Science.gov (United States)

    Becker, Carola; Türkay, Michael; Brandis, Dirk

    2012-11-01

    The male copulatory system of the European pinnotherid species Pinnotheres pisum, Pinnotheres pectunculi, and Nepinnotheres pinnotheres was investigated by gross morphology, scanning electron microscopy, histological methods, and confocal laser scanning microscopy. The brachyuran copulatory system is consistently formed by paired penes and two pairs of abdominal appendages, the gonopods, functioning in sperm transfer. In pinnotherids, the long first gonopods transfer the sperm mass into the female ducts. The first gonopod has the ejaculatory canal inside that opens both basally and distally. The second gonopod is solid, short, and conical. During copulation, the penis and the second gonopod are inserted into the basal lumen of the first gonopod. While the penis injects the sperm mass, the second gonopod functions in the transport of spermatozoa inside the ejaculatory canal toward its distal opening. The second gonopod is adapted for the sealing of the tubular system in the first gonopod by its specific shape and the ability to swell. Longitudinal cuticle foldings of the second gonopod hook into structures inside the first gonopod. The second gonopod can interact with the penis during copulation by a flexible flap separating the lumina in which the second gonopod and the penis are inserted.

  12. Morphology of the female reproductive system of European pea crabs (Crustacea, Decapoda, Brachyura, Pinnotheridae).

    Science.gov (United States)

    Becker, Carola; Brandis, Dirk; Storch, Volker

    2011-01-01

    Commensal pea crabs inhabiting bivalves have a high reproductive output due to the extension andfecundity of the ovary. We studied the underlying morphology of the female reproductive system in the Pinnotheridae Pinnotheres pisum, Pinnotheres pectunculi and Nepinnotheres pinnotheres using light microscopy and transmission electron microscopy (TEM). Eubrachyura have internal fertilization: the paired vaginas enlarge into storage structures, the spermathecae, which are connected to the ovaries by oviducts. Sperm is stored inside the spermathecae until the oocytes are mature. The oocytes are transported by oviducts into the spermathecae where fertilization takes place. In the investigated pinnotherids, the vagina is of the "concave pattern" (sensu Hartnoll1968): musculature is attached alongside flexible parts of the vagina wall that controls the dimension of its lumen. The genital opening is closed by a muscular mobile operculum. The spermatheca can be divided into two distinct regions by function and morphology. The ventral part includes the connection with vagina and oviduct and is regarded as the zone where fertilization takes place. It is lined with cuticle except where the oviduct enters the spermatheca by the "holocrine transfer tissue." At ovulation, the oocytes have to pass through this multilayered glandular epithelium performing holocrine secretion. The dorsal part of the spermatheca is considered as the main sperm storage area. It is lined by a highly secretory apocrine glandular epithelium. Thus, two different forms of secretion occur in the spermathecae of pinnotherids. The definite role of secretion in sperm storage and fertilization is not yet resolved, but it is notable that structure and function of spermathecal secretion are more complex in pinnotherids, and probably more efficient, than in other brachyuran crabs.

  13. Genetic diversity of bacteria associated with the hindgut of the terrestrial crustacean Porcellio scaber (Crustacea: Isopoda).

    Science.gov (United States)

    Kostanjsek, Rok; Strus, Jasna; Avgustin, Gorazd

    2002-06-01

    Molecular approaches were used to examine the genetic diversity of bacteria associated with the gut wall of the terrestrial isopod Porcellio scaber and to determine whether an autochthonous microflora exists in the P. scaber hindgut. 16S ribosomal genes were amplified from the total DNA isolated from thoroughly washed papillate regions of the hindgut, where the highest concentrations of bacteria are commonly found. The amplified genes were cloned, sequenced and phylogenetically analysed. The results implied an unexpectedly large diversity of microflora associated with the cuticle of the hindgut. Almost half of the retrieved sequences were found to be less than 80% homologous with any of the known sequences available at DNA data banks. Most of these sequences were clustered in one of three groups, and were clearly distant from the sequences of other bacterial taxa, indicating that they could represent novel bacterial species or even genera. More than two thirds of the sequences were found to be phylogenetically related to sequences from bacteria typically isolated from human and animal intestines, e.g. streptococci, enterococci, and members of the genus Bacteroides. The majority of the remaining sequences were most closely related to typical soil bacteria, e.g. bacilli and pseudomonads. The facts that a large proportion of the retrieved sequences was related to the sequences of bacteria, which are autochthonous to intestinal ecosystems, and that bacteria, specifically attached to the cuticular spines, were observed, indicate that truly autochthonous bacteria may well be present in the hindgut of P. scaber.

  14. De pissebedden (Crustacea Isopoda, Oniscoidea) van de ondergrondse kalksteengroeven in Zuid-Limburg

    NARCIS (Netherlands)

    Holthuis, L.B.

    1983-01-01

    In the limestone quarries in the southern part of the province of Limburg, Netherlands, 13 species of Isopoda Oniscoidea were found during an intensive exploration (1946-1958) of the obscuricole fauna of these artificial caves. None of the species found is troglobiont, all have to be classed as trog

  15. Formation of the hindgut cuticular lining during embryonic development of Porcellio scaber (Crustacea, Isopoda)

    Science.gov (United States)

    Mrak, Polona; Bogataj, Urban; Štrus, Jasna; Žnidaršič, Nada

    2015-01-01

    Abstract The hindgut and foregut in terrestrial isopod crustaceans are ectodermal parts of the digestive system and are lined by cuticle, an apical extracellular matrix secreted by epithelial cells. Morphogenesis of the digestive system was reported in previous studies, but differentiation of the gut cuticle was not followed in detail. This study is focused on ultrastructural analyses of hindgut apical matrices and cuticle in selected intramarsupial developmental stages of the terrestrial isopod Porcellio scaber in comparison to adult animals to obtain data on the hindgut cuticular lining differentiation. Our results show that in late embryos of stages 16 and 18 the apical matrix in the hindgut consists of loose material overlaid by a thin intensely ruffled electron dense lamina facing the lumen. The ultrastructural resemblance to the embryonic epidermal matrices described in several arthropods suggests a common principle in chitinous matrix differentiation. The hindgut matrix in the prehatching embryo of stage 19 shows characteristics of the hindgut cuticle, specifically alignment to the apical epithelial surface and a prominent electron dense layer of epicuticle. In the preceding embryonic stage – stage 18 – an electron dense lamina, closely apposed to the apical cell membrane, is evident and is considered as the first epicuticle formation. In marsupial mancae the advanced features of the hindgut cuticle and epithelium are evident: a more prominent epicuticular layer, formation of cuticular spines and an extensive apical labyrinth. In comparison to the hindgut cuticle of adults, the hindgut cuticle of marsupial manca and in particular the electron dense epicuticular layer are much thinner and the difference between cuticle architecture in the anterior chamber and in the papillate region is not yet distinguishable. Differences from the hindgut cuticle in adults imply not fully developed structure and function of the hindgut cuticle in marsupial manca, possibly related also to different environments, as mancae develop in marsupial fluid. Bacteria, evenly distributed within the homogenous electron dense material in the hindgut lumen, were observed only in one specimen of early marsupial manca. The morphological features of gut cuticle renewal are evident in the late marsupial mancae, and are similar to those observed in the exoskeleton. PMID:26261443

  16. Amorphous and crystalline calcium carbonate distribution in the tergite cuticle of moulting Porcellio scaber (Isopoda, Crustacea).

    Science.gov (United States)

    Neues, Frank; Hild, Sabine; Epple, Matthias; Marti, Othmar; Ziegler, Andreas

    2011-07-01

    The main mineral components of the isopod cuticle consists of crystalline magnesium calcite and amorphous calcium carbonate. During moulting isopods moult first the posterior and then the anterior half of the body. In terrestrial species calcium carbonate is subject to resorption, storage and recycling in order to retain significant fractions of the mineral during the moulting cycle. We used synchrotron X-ray powder diffraction, elemental analysis and Raman spectroscopy to quantify the ACC/calcite ratio, the mineral phase distribution and the composition within the anterior and posterior tergite cuticle during eight different stages of the moulting cycle of Porcellio scaber. The results show that most of the amorphous calcium carbonate (ACC) is resorbed from the cuticle, whereas calcite remains in the old cuticle and is shed during moulting. During premoult resorption of ACC from the posterior cuticle is accompanied by an increase within the anterior tergites, and mineralization of the new posterior cuticle by resorption of mineral from the anterior cuticle. This suggests that one reason for using ACC in cuticle mineralization is to facilitate resorption and recycling of cuticular calcium carbonate. Furthermore we show that ACC precedes the formation of calcite in distal layers of the tergite cuticle.

  17. Toxicity of abamectin to the terrestrial isopod Porcellio scaber (Isopoda, Crustacea).

    Science.gov (United States)

    Kolar, Lucija; Jemec, Anita; van Gestel, Cornelis A M; Valant, Janez; Hrzenjak, Rok; Erzen, Nevenka Kozuh; Zidar, Primoz

    2010-06-01

    To determine effects of the antiparasitic veterinary drug abamectin on the isopod Porcellio scaber, animals were exposed for 21 days to Lufa 2.2 soil spiked at concentrations of 3-300 mg/kg dry soil. After exposure, abamectin residues in the isopods were analysed using a novel analytical method. Toxicity was evaluated on different levels of biological organisation: biochemical, cellular and the individual organism. Measurements included glutathione S-transferase (GST) activity and stability of cell membranes in the digestive gland, animal mass gain or loss, food consumption, behaviour and mortality. LC50 for the effect of abamectin on survival of P. scaber was 71 mg/kg dry soil. The most obvious sublethal effects were reduced food consumption and decreased body mass (NOEC 3 mg/kg dry soil). Additionally, loss of digging activity and reduced GST activity (NOEC 30 mg/kg dry soil) and cell membrane destabilization (NOEC 10 mg/kg dry soil) were recorded. Abamectin only slightly accumulated in the isopods, with bioaccumulation factors always being <0.1. Based on these results and current information on environmental levels of abamectin, it is not likely that isopods will be affected by abamectin, but further studies with exposure through faeces are recommended.

  18. Assimilation of zinc by Porcellio scaber (Isopoda, Crustacea) exposed to zinc

    Energy Technology Data Exchange (ETDEWEB)

    Bibic, A.; Drobne, D.; Strus, J. [Univ. of Ljubijana (Slovenia)

    1997-05-01

    The ability of terrestrial isopods to accumulate high amounts of metals, to survive in industrially polluted areas and respond to environmental contaminants in a dose-dependent manner makes them one of the most favorite experimental organisms for terrestrial ecotoxicology. Understanding metal uptake, assimilation and loss by these animals is important to explain how they cope with polluted environments. Metal uptake depends on the rate of food consumption, on metal availability in the food, on the pH inside the gut and some other factors. Isopods respond to high metal concentrations in the food in different ways and try to avoid the negative effects of metal poisoning. Zinc is one of the metals present in high concentrations in industrially polluted areas. Zinc poisoning may be avoided by the regulation of the consumption rate, by behavioral response, by storing metals in the hepatopancreas as insoluble granules, and by fecal, and possibly urinary, excretion. Zinc in organisms is a constituent of more than 200 metalloenzymes and other metabolic compounds and assures stability of biological molecules and structures. High Zn levels in food cause a reduction of feeding rate, affect growth and reproduction, cause changes in the structure of the digestive glands and influence the duration of the molting cycle. The present study investigated zinc assimilation by Porcellio scaber exposed to leaves contaminated with radioactively labeled zinc at five different concentrations. 17 refs., 2 figs., 2 tabs.

  19. The glycosylated androgenic hormone of the terrestrial isopod Porcellio scaber (Crustacea).

    Science.gov (United States)

    Grève, Pierre; Braquart-Varnier, Christine; Strub, Jean-Marc; Félix, Christine; Van Dorsselaer, Alain; Martin, Gilbert

    2004-05-01

    It appears from grafting experiments that the androgenic hormone (AH) of terrestrial isopods has a narrow species-specificity [J. Crust. Biol. 19 (1999) 684], even if AH of different species shared common epitopes [Gen. Comp. Endocrinol. 125 (2002) 218]. To date only the glycosylated AH of the woodlouse Armadillidium vulgare has been deciphered by us [Ann. New York Acad. Sci. 839 (1998) 111; Eur. J. Biochem. 262 (1999) 727] and [Biochem. Biophys. Res. Commun. 264 (1999) 419] have confirmed the primary structure of this protein. We reported in the present paper the characterization of the AH in another species Porcellio scaber by a combination of microsequencing, mass spectrometry, and molecular cloning. We found only one glycoform which consisted of two peptide chains, A and B, of 31 and 44 amino acids, respectively, with A chain carrying on Asn18 a N-glycosylated moiety, size of which has been determined by MALDI-MS measurements. The expected structure of the glycosylation was proposed. The deduced amino acid sequence of the AH precursor was mainly identical to the one obtained independently by another group [Zool. Sci. 20 (2003) 75]. We also showed that AH gene is exclusively expressed in androgenic glands. Sequence comparison with A. vulgare and P. scaber (population of Japan) AH was discussed.

  20. The effect of Zn on the digestive gland epithelium of Porcellio scaber (Isopoda, Crustacea).

    Science.gov (United States)

    Drobne, D; Strus, J

    1996-01-01

    The effect of zinc (Zn)-contaminated food on the shape of digestive gland epithelium was studied in the terrestrial isopod, Porcellio scaber. In animals fed with 5,000 micrograms Zn g-1 dry wt. of food, the epithelium was flattened in the anterior part of the gland tube. In the posterior part of the gland tube, the shape and size of cells did not change drastically, but they had folded apical surface. In animals fed with more Zn-contaminated food (10,000 micrograms Zn g-1 dry wt.) the epithelium was uniformly flattened and the basal lamina was intensively folded. In both cases, reduction of lipid bodies was evident. The possibility of using the shape of the gland epithelium as a biomarker of toxic chemicals is discussed.