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Sample records for hyalella azteca amphipoda

  1. 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

    2018-02-01

    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 as a result of their high hydrophobicity and low toxicity thresholds, which often fall below the analytical methods detection limits (MDLs). 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 the present study, we quantified toxicity loss during storage and testing, using both natural and synthetic water, and presented a tool to enhance toxic signal strength for improved sensitivity of H. azteca toxicity tests. The average half-life during storage in low-density polyethylene (LDPE) cubitainers (Fisher Scientific) at 4 °C of 5 pyrethroids (permethrin, bifenthrin, lambda-cyhalothrin, cyfluthrin, and 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. Environ Toxicol Chem 2018;37:462-472. © 2017 SETAC. © 2017 SETAC.

  2. Estratégia reprodutiva e dinâmica populacional de Hyalella azteca (Crustacea: Amphipoda) : integração de parâmetros populacionais em testes de ecotoxicidade

    OpenAIRE

    Guilherme Lessa Ferreira

    2016-01-01

    Resumo: Hyalella azteca tem sido amplamente utilizada em testes de ecotoxicologia. Algumas características, como facilidade de cultivo, ciclo de vida curto e sensibilidade a diversas classes de contaminantes, a tornam adequada para experimentos com abordagem populacional, os LTRE (Life Table Response Experiment). Entretanto, estudos recentes com marcadores moleculares revelam que a espécie representa na verdade um complexo de espécies, fator complicador na interpretação dos resultados de test...

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

    Science.gov (United States)

    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.

  4. 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.

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

    Directory of Open Access Journals (Sweden)

    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

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

    Science.gov (United States)

    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. Copyright © 2013 SETAC.

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

    DEFF Research Database (Denmark)

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

    . H. azteca is widely distributed through North America where it is common as a food source for birds, fish and large invertebrates and is therefore considered as an ecologically important organism. In addition H. azteca has been extensively used as a test organism and is generally sensitive...... 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...

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

    Science.gov (United States)

    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...

  9. 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...

  10. 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 μ...

  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)

    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.

  13. 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.

  14. Toxicity of stormwater treatment pond sediments to Hyallela azteca (Amphipoda)

    Science.gov (United States)

    Karouna-Renier, N.K.; Sparling, D.W.

    1997-01-01

    Stormwater wetlands are created to contain runoff from human developments and are designed to retain contaminants such as heavy metals, petroleum hydrocarbons, silt, pesticides, and nutrients before the runoff enter natural waterways. Because of this design, stormwater wetlands have a potential of becoming toxic sinks to organisms utilizing the wetlands for habitat. We conducted a 10-day sediment bioassay on Hyallela azteca as part of a larger study on the possible hazards of stormwater wetlands to aquatic invertebrates. Water and sediments from 10 wetlands separated into reference, residential, commercial, and highway land uses were used. No differences in survival were observed among land use categories, possibly because the ratio of acid volatile sulfides/simultaneously extractable metals (AVS/SEM) was > 1.0 for all of the ponds tested; values > 1 in this ratio are indications that toxic metals may not be bioavailable. Survival and growth rates correlated positively with AVS.

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

    Science.gov (United States)

    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 surviva...

  16. 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

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

    International Nuclear Information System (INIS)

    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 (60 mg CaCO 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 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

  18. The Hyalella (Crustacea: Amphipoda) species cloud of the ancient Lake Titicaca originated from multiple colonizations.

    Science.gov (United States)

    Adamowicz, Sarah J; Marinone, María Cristina; Menu-Marque, Silvina; Martin, Jeffrey W; Allen, Daniel C; Pyle, Michelle N; De Los Ríos, Patricio; Sobel, Crystal N; Ibañez, Carla; Pinto, Julio; Witt, Jonathan D S

    2018-08-01

    Ancient lakes are renowned for their exceptional diversity of endemic species. As model systems for the study of sympatric speciation, it is necessary to understand whether a given hypothesized species flock is of monophyletic or polyphyletic origin. Here, we present the first molecular characterization of the Hyalella (Crustacea: Amphipoda) species complex of Lake Titicaca, using COI and 28S DNA sequences, including samples from the connected Small and Large Lakes that comprise Lake Titicaca as well as from a broader survey of southern South American sites. At least five evolutionarily distant lineages are present within Lake Titicaca, which were estimated to have diverged from one another 12-20 MYA. These major lineages are dispersed throughout the broader South American Hyalella phylogeny, with each lineage representing at least one independent colonization of the lake. Moreover, complex genetic relationships are revealed between Lake Titicaca individuals and those from surrounding water bodies, which may be explained by repeated dispersal into and out of the lake, combined with parallel intralacustrine diversification within two separate clades. Although further work in deeper waters will be required to determine the number of species present and modes of diversification, our results strongly indicate that this amphipod species cloud is polyphyletic with a complex geographic history. Copyright © 2018 Elsevier Inc. All rights reserved.

  19. 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.

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

    Science.gov (United States)

    Smith, S; Lizotte, R E

    2007-11-01

    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 Mississippi, USA with varying water quality characteristics. H. azteca 48-h immobilization EC50 values ranged from 1.4 to 15.7 ng/L and 0.6 to 13.4 ng/L for lambda-cyhalothrin and gamma-cyhalothrin, respectively. For both pyrethroids, EC50 values linearly increased as turbidity, suspended solids, dissolved organic carbon and chlorophyll a concentrations increased.

  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. © 2015 SETAC.

  2. 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

  3. 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.

  4. 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...

  5. 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

  6. 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

    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

  7. 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. © 2015 Crown in the Right of Canada.

  8. 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.

  9. 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

  10. A new species of Hyalella from the Andes in Perú (Crustacea: Amphipoda: Hyalellidae).

    Science.gov (United States)

    González, Exequiel R; Watling, Les

    2002-06-01

    Hyalella pauperocavae n. sp. from Huancayo, Perú, is described. Five other epigean freshwater amphipods have been described from Peru (excluding Lake Titicaca), but the lack of type material and poor descriptions do not allow the assignment of the species described here to any of the names known for the area.

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

    Energy Technology Data Exchange (ETDEWEB)

    Weil, Mirco, E-mail: m.weil@ect.de [ECT Oekotoxikologie GmbH, Böttgerstrasse 2-14, 65439 Flörsheim (Germany); Meißner, Tobias, E-mail: tmeiss@gmx.net [Fraunhofer Institute for Ceramic Technologies and Systems, Winterbergstrasse 28, 01277 Dresden (Germany); Springer, Armin, E-mail: armin.springer@nano.tu-dresden.de [Dresden University of Technology, Budapesterstrasse 27, 01069 Dresden (Germany); Bundschuh, Mirco, E-mail: mirco.bundschuh@slu.se [Department of Aquatic Sciences and Assessment, Swedish University of Agricultural Sciences, Uppsala (Sweden); Institute for Environmental Sciences, University of Koblenz-Landau, Forststrasse 7, 76829 Landau (Germany); Hübler, Lydia, E-mail: lydia.huebler@gmail.com [ECT Oekotoxikologie GmbH, Böttgerstrasse 2-14, 65439 Flörsheim (Germany); Schulz, Ralf, E-mail: schulz@uni-landau.de [Institute for Environmental Sciences, University of Koblenz-Landau, Forststrasse 7, 76829 Landau (Germany); Duis, Karen, E-mail: k-duis@ect.de [ECT Oekotoxikologie GmbH, Böttgerstrasse 2-14, 65439 Flörsheim (Germany)

    2016-12-15

    Highlights: • Effects on growth, reproduction and survival at ≥12.5 mg of oxidized Carbo-Iron/L were studied. • Carbo-Iron significantly increases sensitivity of offspring from exposed amphipods. • Toxicity is most likely mediated by an impaired uptake of nutrients and energy. - Abstract: For in situ remediation of groundwater contaminated by halogenated hydrocarbons Carbo-Iron{sup ®}, a composite of microscale activated carbon and nano Fe{sup 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{sup 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 100 mg/L. While an uptake of Carbo-Iron into the gut was

  12. 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

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

    International Nuclear Information System (INIS)

    Willming, Morgan M.; Maul, Jonathan D.

    2016-01-01

    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. - Highlights: • Pyraclostrobin was directly toxic to Hyalella azteca and reduced leaf processing. • Indirect exposure via leaf material did not change H. azteca

  14. A new species of Hyalella from the Andes in Perú (Crustacea: Amphipoda: Hyalellidae

    Directory of Open Access Journals (Sweden)

    Exequiel R González

    2002-06-01

    Full Text Available Hyalella pauperocavae n. sp. from Huancayo, Perú, is described. Five other epigean freshwater amphipods have been described from Peru (excluding Lake Titicaca, but the lack of type material and poor descriptions do not allow the assignment of the species described here to any of the names known for the areaSe describe la especie Hyalella pauperocavae n. sp. recolectada en la localidad de Huancayo, Perú. Otras cinco especies de anfípodos epígeos se conocen para el Perú (excluyendo aquellas presentes en el Lago Titicaca. La ausencia de material tipo y descripciones poco claras impidieron la asignación de la especie descrita aquí a alguno de los nombres conocidos para el área

  15. Distributional patterns of the South American species of Hyalella (Amphipoda: Hyalellidae)

    OpenAIRE

    De los Ríos-Escalante, Patricio; Morrone, Juan J; Rivera, Reinaldo

    2012-01-01

    Distributional patterns of the South American species of the freshwater amphipod genus Hyalella were analysed using a panbiogeographic approach. Five generalized tracks were found: (1) northern Andes to Lake Titicaca (H. dielaii, H. meinerti, H. dybowskii, H.jelskii, H. lubominsky, and H. pauperocavae; (2) lake Titicaca (H. armata, H. cuprea, H. latinamus, H. lucifugax, H. montforti, H. neveulemairei, H. robusta, H. tiwanaku, H. simplex simplex, and H. solida); (3) central Andes (H. fossamanc...

  16. 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.

  17. 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

  18. 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. Copyright © 2016. Published by Elsevier Ltd.

  19. 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.

  20. Relative sensitivity of an amphipod Hyalella azteca, a midge Chironomus dilutus, and a unionid mussel Lampsilis siliquoidea to a toxic sediment

    Science.gov (United States)

    Ingersoll, Christopher G.; Kunz, James L.; Hughes, Jamie P.; Wang, Ning; Ireland, D. Scott; Mount, David R.; Hockett, J. Russell; Valenti, Ted W

    2015-01-01

    The objective of the present study was to evaluate the relative sensitivity of test organisms in exposures to dilutions of a highly toxic sediment contaminated with metals and organic compounds. One dilution series was prepared using control sand (low total organic carbon [TOC; TOC [∼10% TOC, higher binding capacity for contaminants]). Test organisms included an amphipod (Hyalella azteca; 10-d and 28-d exposures), a midge (Chironomus dilutus; 20-d and 48-d exposures started with <1-h-old larvae, and 13-d and 48-d exposures started with 7-d-old larvae), and a unionid mussel (Lampsilis siliquoidea; 28-d exposures). Relative species sensitivity depended on the toxicity endpoint and the diluent. All 3 species were more sensitive in sand dilutions than in West Bearskin Lake sediment dilutions. The <1-h-old C. dilutus were more sensitive than 7-d-old C. dilutus, but replicate variability was high in exposures started with the younger midge larvae. Larval biomass and adult emergence endpoints of C. dilutus exhibited a similar sensitivity. Survival, weight, and biomass of H. azteca were more sensitive endpoints in 28-d exposures than in 10-d exposures. Weight and biomass of L. siliquoidea were sensitive endpoints in both sand and West Bearskin Lake sediment dilutions. Metals, ammonia, oil, and other organic contaminants may have contributed to the observed toxicity.

  1. 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

    OpenAIRE

    Patricio De los Ríos-Escalante; Andrés Mansilla; Christopher B Anderson

    2012-01-01

    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. falklande...

  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, Christopher G.; Stubblefield, William A.; Cardwell, Allison S.

    2018-01-01

    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 data set to update the WQC. Freshwater mussels are one of the most imperiled groups of animals in the world, but little is known about their sensitivity 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. The acute 50% effect concentration (EC50) for survival of both species was >6200 μg total Al/L. The EC50 was greater than all acute values in the USEPA acute Al data set for freshwater species at a pH range of 5.0 to <6.5 and hardness normalized to 100 mg/L, indicating that the mussel and amphipod were insensitive to Al in acute exposures. The chronic 20% effect concentration (EC20) based on dry weight was 163 μg total Al/L for the mussel and 409 μg total Al/L for the amphipod. Addition of the EC20s to the USEPA chronic Al data set for pH 5.0 to <6.5 would rank the mussel (L. siliquoidea) as the fourth most sensitive species and the amphipod (H. azteca) as the fifth most sensitive species, indicating the 2 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. 

  3. 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, Christopher G.; Stubblefield, William A.; Cardwell, Allison S.

    2018-01-01

    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 data set to update the WQC. Freshwater mussels are one of the most imperiled groups of animals in the world, but little is known about their sensitivity 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. The acute 50% effect concentration (EC50) for survival of both species was >6200 μg total Al/L. The EC50 was greater than all acute values in the USEPA acute Al data set for freshwater species at a pH range of 5.0 to based on dry weight was 163 μg total Al/L for the mussel and 409 μg total Al/L for the amphipod. Addition of the EC20s to the USEPA chronic Al data set for pH 5.0 to of the chronic data from the present study and recalculation of the chronic criterion would likely lower the proposed chronic criterion. 

  4. 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. © 2016 SETAC.

  5. 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

  6. Effect of Roundup® (glyphosate formulation) in the energy metabolism and reproductive traits of Hyalella castroi (Crustacea, Amphipoda, Dogielinotidae).

    Science.gov (United States)

    Dutra, Bibiana Kaiser; Fernandes, Felipe Amorim; Failace, Daniela Motta; Oliveira, Guendalina Turcato

    2011-01-01

    Roundup(®) (glyphosate formulation) is a nonselective and posts emergent herbicide used for controlling aquatic weeds and different concentrations are used in cultures around the world. The objective of this investigation was to examine the effects of Roundup(®) (glyphosate formulation) on the biochemical composition, levels of lipoperoxidation, Na(+)/K(+)ATPase activity and reproductive traits in the Hyalella castroi. Amphipods were collected in summer 2009, in the southern Brazilian highlands. In the laboratory, the animals were kept in aquariums under controlled conditions for 7 days, and after this period they were exposed to 0.36, 0.52, 1.08 and 2.16 mg/l of glyphosate for 7 days. After the period of exposure, the animals were immediately frozen for determination of glycogen, proteins, lipids, triglycerides, cholesterol, levels of lipoperoxidation, and Na(+)/K(+)ATPase activity. During each day of the cultivation reproductive traits (number of reproductive pairs, ovigerous females and eggs in the marsupium) were observed. All concentrations of Roundup(®) induced significant decreases in all biochemical parameters and Na(+)/K(+)ATPase activity, and significant increase in lipoperoxidation levels. Showing this form a potentially toxic effect at very low concentrations, this pattern of results can lead to significant changes in trophic structure of limnic environments because these amphipods are important links in food chain in these habitats.

  7. 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

  8. Revisión de la distribución de Hyalella Smith, 1874 (Crustacea, Amphipoda) en la Patagonia e islas adyacentes

    OpenAIRE

    De los Ríos-Escalante,Patricio; Mansilla,Andrés; Anderson,Christopher B

    2012-01-01

    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. falklande...

  9. Effects of photoperiod and temperature on the induction and termination of reproductive resting stage in the freshwater amphipod Hyalella azteca (Saussure)

    Energy Technology Data Exchange (ETDEWEB)

    deMarch, B.G.E.

    1977-10-01

    Three experiments, one on the induction of reproductive resting stage and two on its termination, were performed to determine the effects of various combinations of temperature and photoperiod on the induction and termination of reproduction in Hyallella azteca. These showed that only photoperiod determined whether reproduction was continued or discontinued but that temperature influenced the rate of all changes. The 12L--12D photoperiod terminated reproduction for at least 4 months at temperatures between 12 and 25/sup 0/C in animals previously reproducing at a 16L--8D photoperiod. The 12L--12D photoperiod also induced reproduction at temperatures between 16 and 26/sup 0/C in animals previously held in a reproductive resting stage in dim light. In contrast, the 16L--8D photoperiod induced and maintained reproduction consistently, and the 8L--16D photoperiod halted reproduction and maintained a reproductive resting stage consistently. The induction of reproduction occurred faster at higher temperatures. It is believed that although photoperiod is the main cue in the induction and termination of reproduction, active reproduction takes place when environmental temperatures are 20 to 26/sup 0/C, since optimum reproduction and growth rates occur in this range. The adaptive advantage and the biogeographic variability of the photoperiodic response are discussed.

  10. 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

  11. Fish, Benthic-Macroinvertebrate, and Stream-Habitat Data From Two Estuaries Near Galveston Bay, Texas, 2000-2001

    Science.gov (United States)

    2002-01-01

    0 0 0 1 0 2 0 0 0 2 5 Amphipoda Hyalellidae Hyalella azteca ( Saussure ) 0 0 16 0 0 0 0 0 0 0 16 Capitellida Capitellidae Mediomastus ambiseta (Hartman...0 0 0 0 0 0 0 0 14 0 14 Amphipoda Gammaridae Gammarus sp. 0 0 0 0 0 0 0 0 28 0 28 Amphipoda Hyalellidae Hyalella azteca ( Saussure ) 47 0 18 0 0 0 0 0

  12. 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)

  13. Acute toxicity of fire-retardant and foam-suppressant chemicals to yalella azteca (Saussure)

    Science.gov (United States)

    McDonald, Susan F.; Hamilton, Steven J.; Buhl, Kevin J.; Heisinger, James F.

    1997-01-01

    Acute toxicity tests were conducted with Hyalella azteca Saussure (an amphipod) exposed in soft and hard waters to three fire retardants (Fire-Trol GTS-R, Fire-Trol LCG-R, and Phos-Chek D75-F) and two foam suppressants (Phos-Chek WD-881 and Silv-Ex). The chemicals were slightly to moderately toxic to amphipods. The most toxic chemical to amphipods in soft and hard water was Phos-Chek WD-881 (96-h mean lethal concentration [LC50] equal to 10 mg/L and 22 mg/L, respectively), and the least toxic chemical to amphipods in soft water was Fire-Trol GTS-R (96-h LC50 equal to 127 mg/L) and in hard water was Fire-Trol LCG-R (96-h LC50 equal to 535 mg/L). Concentrations of ammonia in tests with the three fire retardants and both water types were greater than reported LC50 values and probably were the major toxic component. Estimated un-ionized ammonia concentrations near the LC50 were frequently less than the reported LC50 ammonia concentrations for amphipods. The three fire retardants were more toxic in soft water than in hard water even though ammonia and un-ionized ammonia concentrations were higher in hard water tests than in soft water tests. The accidental entry of fire-fighting chemicals into aquatic environments could adversely affect aquatic invertebrates, thereby disrupting ecosystem function.

  14. Los felinos en la escultura azteca

    OpenAIRE

    Díaz Balerdi, Ignacio

    2011-01-01

    Se trata de un estudio pormenorizado del motivo felino tal como aparece representado en la escultura azteca. Es un estudio tanto formal como iconográfico, que parte de la ubicación de las piezas en un contexto fruto de la tradición estética del altiplano mexicano, rastrea en los significados que tradicionalmente se han adjudicado al motivo felino, busca sus interconexiones y analiza la producción artística en tres niveles: el real, el ritual y el mítico, los cuales son otras tantas manifestac...

  15. El sistema de dominación azteca el imperio tepaneca

    OpenAIRE

    Santamarina Novillo, Carlos

    2011-01-01

    Este trabajo parte de una consideración teórica de las relaciones políticas de dominación en las sociedades preindustriales para acercarse al análisis de la cultura azteca. La Primera Parte se dedica al análisis del sistema de dominación azteca, tratando de elaborar un modelo azteca de imperio. Nos interesa la que denominamos política postconquista: las estrategias empleadas por los vencedores sobre un altepetl para articular su dependencia del imperio. Una de las tesis principales de este tr...

  16. Recovery of ostracod with known ages in differently textured sediments and comparison of toxicity of heavily contaminated sediments with ostracod Heterocypris incongruens and amphipod Hyalella azteca

    Science.gov (United States)

    Stepanova, N. Yu; Nikitin, O. V.; Latypova, V. Z.; Vybornova, I. B.; Galieva, G. S.; Okunev, R. V.

    2018-01-01

    The recovery of 1-, 4-, 6,-, and 8-d-old ostracods (Heterocypris incongruens) from sediments with different texture has been evaluated. The recovery of ostracods at all ages has been in agreement with the acceptability criterion of 80% of survival for sediment tests. The recovery of ostracods has turned out to be equal to or more than 80% for sand and silt sediments, respectively. The comparison of survival rates between ostracods and amphipods has shown good convergence in the tests of heavily contaminated sediments (R2=0.75, pquality criteria (TEC) have been exceeded mostly for total petroleum hydrocarbons (100% samples), Cr (100%), Ni (87%), Cu (87%), Pb (47%), and Cd (53%). The content of acid volatile sulfides (AVS) has been significantly higher than that of simultaneously extracted metals (SEM). The obtained results have indicated that, metals (Cu, Zn, Cd, Ni, and Pb) are non-bioavailable. Only one sample has exceeded TEC for PAHs (dibenz[a,h]anthracene). It was observed that, no significant correlation between the effect of toxicity and the chemical content.

  17. Inter-lab testing of Hyalella azteca water and sediment methods: 1 background and overview of the 42-d survival, growth and reproduction test

    Science.gov (United States)

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

  18. Bayo Azteca, primera variedad mejorada de frijol con resistencia a Apion godmani Wagner Bayo Azteca, first improved bean variety with resistance to Apion godmani Wagner

    OpenAIRE

    Ramón Garza-García; Carmen Jacinto-Hernández; Dagoberto Garza-García

    2010-01-01

    Bayo Azteca, la primera variedad mejorada de frijol (Phaseolus vulgaris L.), con resistencia a una plaga insectil, ha sido obtenida por el programa de frijol del Campo Experimental Valle de México, del Instituto Nacional de Investigaciones Forestales, Agrícolas y Pecuarias por cruzas múltiples, esto involucró un largo proceso de mejora genética. Bayo Azteca es la primera variedad mejorada resistente al picudo del ejote (Apion godmani Wagner), un curculiónido que ataca al frijol en las zonas t...

  19. Tensiones entre el esencialismo azteca y el universalismo New Age a partir del estudio de las danzas “conchero-aztecas

    OpenAIRE

    Torre, Renée de la

    2009-01-01

    El propósito del trabajo es describir y analizar comparativamente dos expresiones contemporáneas de la religiosidad mexhica que se manifiestan en los grupos de danza conocidos como concheros o aztecas. La primera es la versión mexicanista, que se opone al sincretismo con la religión católica y la cultura occidental y que plantea la esencialización de lo “auténticamente” azteca promoviendo la restauración del Anáhuac en el presente; la segunda es una versión sincrética, conocida como neomexica...

  20. 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,

  1. A fresh look at the higher classification of the Siphonoecetini Just, 1983 (Crustacea, Amphipoda, Ischyroceridae) 12

    DEFF Research Database (Denmark)

    Just, Jean-Jose Andre Auzimour

    2017-01-01

    With increased knowledge of the Amphipoda Siphonoecetini over the past 30 years, classification of this group of shallow water benthic amphipods is reappraised. The cerapodids and ericthonids are removed from the Siphonoecetini, and two new tribes, Cerapodini and Ericthonini, are diagnosed in the...

  2. Predation and aggressiveness in host plant protection: a generalization using ants from the genus Azteca

    Science.gov (United States)

    Dejean, Alain; Grangier, Julien; Leroy, Céline; Orivel, Jerôme

    2009-01-01

    In studying the ant genus Azteca, a Neotropical group of arboreal species, we aimed to determine the extent to which the ants use predation and/or aggressiveness to protect their host plants from defoliating insects. We compared a territorially dominant, carton-nester, Azteca chartifex, and three plant-ant species. Azteca alfari and Azteca ovaticeps are associated with the myrmecophyte Cecropia (Cecropiaceae) and their colonies shelter in its hollow branches; whereas Azteca bequaerti is associated with Tococa guianensis (Melastomataceae) and its colonies shelter in leaf pouches situated at the base of the laminas. Whereas A. bequaerti workers react to the vibrations transmitted by the lamina when an alien insect lands on a leaf making it unnecessary for them to patrol their plant, the workers of the three other species rather discover prey by contact. The workers of all four species use a predatory behaviour involving spread-eagling alien insects after recruiting nestmates at short range, and, in some cases, at long range. Because A. alfari and A. ovaticeps discard part of the insects they kill, we deduced that the workers’ predatory behaviour and territorial aggressiveness combine in the biotic defence of their host tree.

  3. ALCANCES TRANSLOCALES DE CULTOS ANCESTRALES: EL CASO DE LAS DANZAS RITUALES AZTECAS

    Directory of Open Access Journals (Sweden)

    Reene De la Torre

    2007-06-01

    Full Text Available Este trabajo trata sobre las transformaciones de identidad que se gestan en los grupos de danza conocidos como aztecas o concheros en su intercambio cultural y encuentro con redes espirituales alternativas o conocidas como movimientos de espiritualidad Nueva Era (o New Age. El objetivo de este trabajo es dar cuenta de los procesos a partir de los cuales la tradición dancística conchera o azteca está siendo trasformada por las dinámicas de la globalización cultural,haciendo de esta tradición mexicana y ancestral, un eslabón de una amplia red New Age de alcances planetarios

  4. First cytogenetic characterization of a species of the arboreal ant genus Azteca Forel, 1978 (Dolichoderinae, Formicidae

    Directory of Open Access Journals (Sweden)

    Danon Cardoso

    2012-03-01

    Full Text Available In this paper we present, for the first time, a detailed karyotype characterization of a species of the genus Azteca (Dolichoderinae, Formicidae. Cerebral ganglia from Azteca trigona Emery, 1893 were excised and submitted to colchicine hypotonic solution and chromosomal preparations were analyzed through conventional staining with Giemsa, C-banding, silver nitrate staining (AgNO3 and sequential base-specific fluorochromes. The analysis shows that A. trigona has a diploid number of 28 chromosomes. The karyotype consists of five metacentric pairs, seven acrocentric pairs and two pseudo-acrocentric pairs, which represents a karyotype formula 2K= 10M + 14A + 4AM and a diploid number of the arms 2AN = 38. The analysis of heterochromatin distribution revealed a positive block on distal region of the short arm of fourth metacentric pair, which was coincident with Ag-NOR band and CMA3 fluorochrome staining, meaning that rDNA sequences are interspaced by GC-rich base pairs sequences. The C-banding also marked short arms of other chromosomes, indicating centric fissions followed by heterochromatin growth. The karyotype analysis of A. trigona allowed the identification of cytogenetic markers that will be helpful in a difficult taxonomic group as Azteca and discussion about evolutionary aspects of the genome organization.

  5. Ecologia populacional dos Amphipoda (Crustacea dos fitais de Caiobá, Matinhos, Paraná, Brasil Population ecolocy of Amphipoda (Crustacea from the phytals of Caiobá, Matinhos, Paraná, Brazil

    Directory of Open Access Journals (Sweden)

    Janete Dubiaski-Silva

    1995-01-01

    Full Text Available Spalial and temporal density distributions of Amphipoda from the phytals of Caiobá are described. Air temperature oscillated from 16ºC (August and May to 23ºC (March, surface water temperature from 17ºC (August to 25ºC (March and the salinity from 29.3‰ (May to 32.8‰ (August. Two samples of 25cm² (for algae less than 5cm long, 100 cm² (for algae between 5-10cm long and whole plants (for algae more than 10cm long were removed with a spatula from the rocky surface at Caiobá Beach, in August/86, November/86, March/87 and May/87. After sorting, the algal substrata were weighted, their adsorption coefficient calculated and the sediment retained among the thallii weighted. The average distance between the branching was measured for all branched algae. The densities were calculated in relation to the weight of the algal substrate in grams. Eight phytals were considered: Ulva fasciata Delile, Padina gymnospora (Kútzing Vickers, Sargassum cymosum Garth, Porphyra atropurpurea (Olivi De Toni, Gelidium sp., Gymnogongrus griffithsiae (Turner Martius, Pterocladia capillacea (Gmelin Bornet &Thurel and Pterosiphonia pennata (Roth Falkenberg, over which nine Amphipoda species live: Ampithoe ramondi Audouin, 1816, Cymadusa filosa Savigny, 1852, Elasmopus pectenicrus Bate, 1857, Hyale media Dana, 1857, Hyale sp.l, Jassa falcata Montagu, 1895 and Sunampithoe pelagica H. Milne-Edwards, 1830 (Gammaridea. Caprella danilevskii Czerniavski, 1861 and Caprella penantis Leach, 1814 (Caprellidea. Amphipoda densities ranged from 0.27 ind.g-1 to 45.68. ind.g-1. The broad-thallii algae Porphyra, Ulva and Padina harbored lower densities of Amphipoda, whereas those finely branched Pterocladia, Pterosiphonia and Gymnogongrus, the highest values and the less branched Sargassum and Gelidium, intermediate values. The high densities found in the finely branched algae had as main contribution the juvenile recruiting of most Amphipoda. The tide level might have influenced

  6. The relationship of metals, bifenthrin, physical habitat metrics, grain size, total organic carbon, dissolved oxygen and conductivity to Hyalella sp. abundance in urban California streams.

    Science.gov (United States)

    Hall, Lenwood W; Anderson, Ronald D

    2013-01-01

    The objectives of this study were to determine the relationship between Hyalella sp. abundance in four urban California streams and the following parameters: (1) 8 bulk metals (As, Cd, Cr, Cu, Pb, Hg, Ni, and Zn) and their associated sediment Threshold Effect Levels (TELs); (2) bifenthrin sediment concentrations; (3) 10 habitat metrics and total score; (4) grain size (% sand, silt and clay); (5) Total Organic Carbon (TOC); (6) dissolved oxygen; and (7) conductivity. California stream data used for this study were collected from Kirker Creek (2006 and 2007), Pleasant Grove Creek (2006, 2007 and 2008), Salinas streams (2009 and 2010) and Arcade Creek (2009 and 2010). Hyalella abundance in the four California streams generally declined when metals concentrations were elevated beyond the TELs. There was also a statistically significant negative relationship between Hyalella abundance and % silt for these 4 California streams as Hyalella were generally not present in silt areas. No statistically significant relationships were reported between Hyalella abundance and metals concentrations, bifenthrin concentrations, habitat metrics, % sand, % clay, TOC, dissolved oxygen and conductivity. The results from this study highlight the complexity of assessing which factors are responsible for determining the abundance of amphipods, such as Hyalella sp., in the natural environment.

  7. Amsterdam Expeditions to the West Indian Islands, Report 14. The taxonomy and zoogeography of the family Bogidiellidae (Crustacea, Amphipoda), with emphasis on the West Indian taxa

    NARCIS (Netherlands)

    Stock, Jan H.

    1981-01-01

    The diagnosis of a family of groundwater Amphipoda, the Bogidiellidae, is revised. Based on a cladistic analysis, the former genus Bogidiella is subdivided. In its present conception, the Bogidiellidae comprise eleven named genera, seven subgenera, and 50 named species, whereas several other taxa

  8. Amsterdam Expeditions to the West Indian Islands, Report 29. Presence of a member of the genus Saliweckelia (Amphipoda) on Tortuga, Venezuela

    NARCIS (Netherlands)

    Lieshout, Van Sylvia E.N.

    1983-01-01

    A population of Saliweckelia (Amphipoda) from Tortuga (Venezuela) is compared with populations from Curaçao and Bonaire (Netherlands Antilles). Considerable variability in a number of characters, within and between the different populations, makes it difficult to ascertain the taxonomic status of

  9. Potential impact of Dare County landfills on Alligator River National Wildlife Refuge

    Science.gov (United States)

    Winger, P.V.; Lasier, P.J.; Augspurger, T.

    2005-01-01

    Runoff of leachate from East Lake and Dare County Construction and Demolition Debris landfills has the potential to impact wildlife resources at Alligator River National Wildlife Refuge, Dare and Hyde Counties, North Carolina. Sediment quality of samples collected in August 2000 at 14 locations down-gradient from the landfills was assessed by measuring metal and organic contaminants in the sediments, chronic toxicity of solid-phase sediment (28-d static-renewal exposures; survival and growth as test endpoints) and acute toxicity of sediment porewater (96-h static exposures) to Hyalella azteca (Crustacea: Amphipoda). In addition, contaminant bioaccumulation from 4 sediments was determined using 28-d exposures of Lumbriculus variegatus (freshwater oligochaete). Although survival was not impaired, length of H. azteca was significantly reduced in sediments from 5 locations. Pore water from 4 locations was acutely toxic to H. azteca. Metals and a few polycyclic aromatic hydrocarbons (PAHs) were bioaccumulated by L. variegatus from the sediments. Several metals and PAHs exceeded sediment quality guidelines, and metals in porewater from several sites exceeded water quality criteria for the protection of aquatic wildlife. Runoff of leachate from the landfills has reduced sediment quality and has the potential to adversely affect wildlife resources at Alligator River National Wildlife Refuge.

  10. Nest structure and occurrence of three species of Azteca (Hymenoptera, Formicidae in Cecropia pachystachya (Urticaceae in non-floodable and floodable pantanal areas Arquitetura de ninho e ocorrência de três espécies de Azteca (Hymenoptera, Formicidae em Cecropia pachystachya (Urticaceae em ambiente alagável e não alagável no Pantanal

    Directory of Open Access Journals (Sweden)

    Alexsandro S. Vieira

    2010-01-01

    Full Text Available Thirty Cecropia pachystachya trees were examined in non-floodable and floodable areas to investigate the association between C. pachystachya and Azteca ants in the Pantanal of Mato Grosso do Sul, Brazil. The species Azteca ovaticeps, Azteca isthmica, and Azteca alfari were found nesting inside domatia of C. pachystachya. A. ovaticeps was the most frequent species in the trees in the floodable area, while A. isthmica and A. alfari, in the non-floodable area. A. ovaticeps and A. isthmica maintained more entrance/exit holes in comparison to A. alfari. All Azteca species maintained entrance/exit holes in the closest domatia to the apical area of the branch, due to proximity to Müllerian and pearl bodies, suggesting that these species of Azteca were influenced by their environment during evolution and became specialized. All internodal septa of each examined branch were perforated by ants, indicating the branches were inhabited by a single colony.Foram analisadas 30 plantas de Cecropia pachystachya em cada ambiente alagável e não alagável no Pantanal sul-mato-grossense, Brasil, com o objetivo de investigar a associação entre formigas Azteca e C. pachystachya. Foram encontradas as espécies Azteca ovaticeps, Azteca isthmica e Azteca alfari nidificando nas domáceas da planta. A. ovaticeps foi mais frequente em plantas de área alagável, enquanto A. isthmica e A. alfari em plantas em área não alagável. A. ovaticeps e A. isthmica apresentaram maior quantidade de orifícios de entrada/saída em relação à A. alfari e todas as espécies mantêm próximo da região apical do ramo, orifícios de entrada/saída nas domáceas, devido à proximidade com os corpúsculos müellerianos e pérola. Isto é, essas espécies de Azteca especializaram-se ao longo da evolução influenciadas pelo ambientes. Todos os septos internodais de cada ramo analisados apresentaram-se perfurados pelas formigas, sugerindo que os mesmos são habitados por uma única colônia.

  11. A new species of Bathymedon Sars, 1892 (Amphipoda: Oedicerotidae from the western Mediterranean bathyal floor

    Directory of Open Access Journals (Sweden)

    Damiá Jaume

    1998-12-01

    Full Text Available Bathymedon longirostris sp. nov. (Amphipoda: Oedicerotidae from the western Mediterranean bathyal suprabenthos is described. It is characterised by the well-developed rostrum; the discrete lateral lobe of head; the elongation of the peduncle segment 3 of the first antenna; the very slender propodus of the second gnathopod, which attains maximum width not at the palm angle, but at about midway along the palm margin; and by the relative length of the carpus of the foregoing limb, sub-equal to propodus. The discovery of a tiny remnant of the 2nd peduncle segment of the first antenna in the new species is commented with regard to the homologation of the peduncle segments in other members of the Family. The new taxon was captured below 593 m over muddy bottoms with pteropod shells and remains of planktonic foraminiferans. It was one of the most common amphipods in the lower slope (below ~ 1000 m, whereas in the depth range comprised between 1250 and 1859 m it was the second dominant species, representing 11.4 % of the total gammarideans captured. The area studied harbours three additional congeneric species, although their populations are mainly concentrated in the upper and middle slope. Over the bottom, adult males of the new species apparently tend to occupy higher levels beyond the water-sediment interface than the rest of demographic categories. The gut content of three individuals revealed a bulk of calcified foraminiferans, a diet in consonance with their massive mandibles. Juvenile individuals were more abundant in winter, whereas adult individuals were clearly dominant in summer, thus suggesting the biological cycle of the species follows some type of periodicity.

  12. The Azteca Chess experience: learning how to share concepts of ecological complexity with small coffee farmers

    Directory of Open Access Journals (Sweden)

    Luís García-Barrios

    2017-06-01

    Full Text Available Small-scale coffee farmers understand certain complex ecological processes, and successfully navigate some of the challenges emerging from the ecological complexity on their farms. It is generally thought that scientific knowledge is able to complement farmers' knowledge. However, for this collaboration to be fruitful, the gap between the knowledge frameworks of both farmers and scientists will need to be closed. We report on the learning results of 14 workshops held in Chiapas, Mexico during 2015 in which 117 small-scale coffee farmers of all genders (30% women and ages who had little schooling were exposed by researchers to a natural history narrative, a multispecies network representation, a board game, and a series of graphical quizzes, all related to a nine-species complex ecological network with potential for autonomous control of the ongoing and devastating coffee rust epidemic that was affecting them. Farmers' retention and understanding of direct and indirect bilateral interactions among organisms was assessed with different methods to elucidate the effect of adding Azteca Chess gaming sessions to a detailed and very graphical lecture. Evaluation methods that were better adapted to farmers' conditions improved learning scores and showed statistically significant age effect (players older than 40 had lower retention scores and gaming effect (lower retention of interactions included in the lecture but not in the game. The combination of lecture and game sessions helped participants better understand cascades of trait-mediated interactions. Participants' debriefings confirmed qualitatively that they learned that beneficial organisms and interactions occur on their farms, and that gaming was enjoyable, motivating, and critical to grasp complex interactions. Many of the farmers concluded that the outcome of these interactions is not unique and not always in favor of rust control but is context dependent. Many concluded that there are

  13. Insecticide toxicity to Hyalella curvispina in runoff and stream water within a soybean farm (Buenos Aires, Argentina).

    Science.gov (United States)

    Mugni, H; Ronco, A; Bonetto, C

    2011-03-01

    Toxicity to the locally dominant amphipod Hyalella curvispina was assessed in a first-order stream running through a cultivated farm. Cypermethrin, chlorpyrifos, endosulfan and glyphosate were sprayed throughout the studied period. Toxicity was assayed under controlled laboratory conditions with runoff and stream water samples taken from the field under steady state and flood conditions. Ephemeral toxicity pulses were observed as a consequence of farm pesticide applications. After pesticide application, runoff water showed 100% mortality to H. curvispina for 1 month, but no mortality thereafter. Toxicity persistence was shortest in stream water, intermediate in stream sediments and longest in soil samples. Runoff had a more important toxicity effect than the exposure to direct aerial fumigation. The regional environmental features determining fast toxicity dissipation are discussed. Copyright © 2010. Published by Elsevier Inc.

  14. The effect of symbiotic ant colonies on plant growth: a test using an Azteca-Cecropia system.

    Directory of Open Access Journals (Sweden)

    Karla N Oliveira

    Full Text Available In studies of ant-plant mutualisms, the role that ants play in increasing the growth rates of their plant partners is potentially a key beneficial service. In the field, we measured the growth of Cecropia glaziovii saplings and compared individuals that were naturally colonized by Azteca muelleri ants with uncolonized plants in different seasons (wet and dry. We also measured light availability as well as attributes that could be influenced by the presence of Azteca colonies, such as herbivory, leaf nutrients (total nitrogen and δ(15N, and investments in defense (total phenolics and leaf mass per area. We found that colonized plants grew faster than uncolonized plants and experienced a lower level of herbivory in both the wet and dry seasons. Colonized plants had higher nitrogen content than uncolonized plants, although the δ(15N, light environment, total phenolics and leaf mass per area, did not differ between colonized and uncolonized plants. Since colonized and uncolonized plants did not differ in the direct defenses that we evaluated, yet herbivory was lower in colonized plants, we conclude that biotic defenses were the most effective protection against herbivores in our system. This result supports the hypothesis that protection provided by ants is an important factor promoting plant growth. Since C. glaziovii is widely distributed among a variety of forests and ecotones, and since we demonstrated a strong relationship with their ant partners, this system can be useful for comparative studies of ant-plant interactions in different habitats. Also, given this study was carried out near the transition to the subtropics, these results help generalize the geographic distribution of this mutualism and may shed light on the persistence of the interactions in the face of climate change.

  15. Alcances translocales de cultos ancestrales: El caso de las danzas rituales aztecas (Translocales reaches of ancestral cults: The case of the Aztec ritual dances

    Directory of Open Access Journals (Sweden)

    Renée de la Torre

    2007-03-01

    Full Text Available Este trabajo trata sobre las transformaciones de identidad que se gestan en los grupos de danza conocidos como aztecas o concheros en su intercambio cultural y encuentro con redes espirituales alternativas o conocidas como movimientos de espiritualidad Nueva Era (o New Age. El objetivo de este trabajo es dar cuenta de los procesos a partir de los cuales la tradición dancística conchera o azteca está siendo trasformada por las dinámicas de la globalización cultural, haciendo de esta tradición mexicana y ancestral, un eslabón de una amplia red New Age de alcances planetarios.

  16. First report of two species of scarab beetles (Coleoptera, Scarabaeidae inside nests of Azteca cf. chartifex Forel (Hymenoptera, Formicidae in Brazilian Amazonian Rainforest

    Directory of Open Access Journals (Sweden)

    João Rafael Alves-Oliveira

    Full Text Available ABSTRACT We report for the first time the occurrence of two species of scarab beetles, Phileurus carinatus declivis Prell, 1914 (Scarabaeidae: Dynastinae and Cyclidius elongatus (Olivier, 1789 (Cetoniinae: Cremastocheilini inside nests of Azteca cf. chartifex Forel, 1896, a neotropical arboreal ant species. This report indicates that these two beetle species are associated, at least as inquilines, to this ant species, although the nature of this relationship remains unclear.

  17. Disentangling endogenous versus exogenous pattern formation in spatial ecology: a case study of the ant Azteca sericeasur in southern Mexico.

    Science.gov (United States)

    Li, Kevin; Vandermeer, John H; Perfecto, Ivette

    2016-05-01

    Spatial patterns in ecology can be described as reflective of environmental heterogeneity (exogenous), or emergent from dynamic relationships between interacting species (endogenous), but few empirical studies focus on the combination. The spatial distribution of the nests of Azteca sericeasur, a keystone tropical arboreal ant, is thought to form endogenous spatial patterns among the shade trees of a coffee plantation through self-regulating interactions with controlling agents (i.e. natural enemies). Using inhomogeneous point process models, we found evidence for both types of processes in the spatial distribution of A. sericeasur. Each year's nest distribution was determined mainly by a density-dependent relationship with the previous year's lagged nest density; but using a novel application of a Thomas cluster process to account for the effects of nest clustering, we found that nest distribution also correlated significantly with tree density in the later years of the study. This coincided with the initiation of agricultural intensification and tree felling on the coffee farm. The emergence of this significant exogenous effect, along with the changing character of the density-dependent effect of lagged nest density, provides clues to the mechanism behind a unique phenomenon observed in the plot, that of an increase in nest population despite resource limitation in nest sites. Our results have implications in coffee agroecological management, as this system provides important biocontrol ecosystem services. Further research is needed, however, to understand the effective scales at which these relationships occur.

  18. First record of Parelasmopus setiger Chevreux, 1901 from Singapore, including synonymization of Parelasmopus siamensis Wongkamhaeng, Coleman & Pholpunthin, 2013 with Parelasmopus setiger (Crustacea, Amphipoda, Maeridae

    Directory of Open Access Journals (Sweden)

    Azman Abdul Rahim

    2015-04-01

    Full Text Available Parelasmopus setiger has been widely described from tropical to subtropical regions from Philippine Islands, Sulu Sea, Indonesia, Australia, north Indian Ocean and the Seychelles by several authors. The present study provides detailed descriptions of Parelasmopus setiger Chevreux, 1901 (Crustacea: Amphipoda based on newly collected specimens from Pulau Hantu, Singapore. Morphological characters of the specimens closely resemble those of Parelasmopus setiger and Parelasmopus siamensis Wongkamhaeng, Coleman & Pholpunthin, 2013. The specimens of both the species were quite similar to the Singapore specimens, although the shapes of appendages vary with growth and locality; therefore, P. siamensis is synonymized with P. setiger. The following species characteristics for P. setiger are indicated: 1 antenna 1 peduncle with 2 setae; 2 male gnathopod 2 propodus palm transverse; 3 Pereopods 5 to 7 posterior margins with long slender setae; and 4 dorsal carina pattern for pereonite 7 and pleonites 1 to 3.

  19. CHRONIC EFFECTS OF THE HERBICIDE DIURON ON FRESHWATER CLADOCERANS,AMPHIPODS,MIDGES,MINNOWS,WORMS, AND SNAILS

    Science.gov (United States)

    The chronic effects of the herbicide diuron on survival and reproduction of Daphnia pulex, and survival and growth of the amphipod Hyalella azteca, the midge Chironomus tentans, juvenile and embro/larval fathead minnows, Pimephales promelas, annelid worms, Lumbriculus variegatus,...

  20. 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.

  1. 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.

  2. Financial effects of the corporative government and ethics in Mexico’s businesses: the case of Cemex and TV-Azteca

    Directory of Open Access Journals (Sweden)

    Pablo Lopez Sarabia

    2007-12-01

    Full Text Available This article shows that the bad practices of the corporative government and the ethical absence can affect the financial performance of the companies  specially  its  market  value.  It  is  analyzed the  TV-Azteca  which  faces  a  swindle  demand for a rebuying of debt violating the regulation of the  versatile  market  of  the  United  States  specially the Sarbanes-Oxley Law, the econometric results show that the value and  the price of  the company have  decreased since  the beginning of the Securities and Exchange Commission (SEC research.  The  Cementos  Mexicanos  (Cemex is a company that developed an internal code of ethics and that adjusted  itself  to the  Código de Mejores Práticas Corporativas (Best Corporative Practices  Code,  besides  being  an  enthusiastic motivator of the  good practices  of the  corporative government.

  3. La participación de Televisa y TV Azteca en la construcción, promoción de imagen y percepción ciudadana, de candidatos y gobernantes mexicanos con financiamiento público

    OpenAIRE

    Orta Vélez, Juan Miguel

    2010-01-01

    En México, gobernantes y candidatos, han aplicado innovadoras formas de promover su imagen, la principal herramienta la constituye el duopolio: Televisa y TV Azteca. Inicialmente las campañas políticas en televisión, consistían en la compra de spots y cobertura en noticieros, es a partir del año 2000, cuando políticos y gobiernos en contubernio con las televisoras, irrumpen esta práctica mediante programas de entretenimiento, deportes, espectáculos, incluso comedia, tomando por sorpresa al te...

  4. The life cycle of Huffmanela huffmani Moravec, 1987 (Nematoda: Trichosomoididae), an endemic marine-relict parasite of Centrarchidae from a Central Texas spring

    Czech Academy of Sciences Publication Activity Database

    Worsham, M.L.D.; Huffman, D. G.; Moravec, František; Gibson, J.R.

    2016-01-01

    Roč. 63, JUN 10 (2016), č. článku 020. ISSN 1803-6465 Institutional support: RVO:60077344 Keywords : swim bladder nematode * Trichinelloidea * development * intermediate host * Amphipoda * Hyalella * Gammarus * fish * USA Subject RIV: EG - Zoology Impact factor: 1.082, year: 2016

  5. Lípidos en el anfípodo Talorchestia margaritae (Amphipoda: Talitridae y su relación con la ecología de la especie

    Directory of Open Access Journals (Sweden)

    Sandra López

    2010-09-01

    Full Text Available T. margaritae cumple un papel importante en la descomposición de restos vegetales y animales en las costas venezolanas. El objetivo fue determinar las diferencias en la composición lipídica entre sexos y talla de la especie. Para esto, especímenes de T. margaritae fueron recolectados en la zona supralitoral de dos playas arenosas: Mangle Quemao y las Mercedes de Paparo. Posteriormente se separaron por talla y sexo determinándoles su peso, densidad, biomasa y perfil lipídico. Todas las categorías presentaron tallas similares entre localidades. Los pesos fueron superiores en los organismos de Mangle Quemao. Los lípidos totales presentaron proporciones similares entre sexos, talla y localidad (3-5%, al igual que los fosfololípidos (20-30%, glicolípidos (Lipids in the amphipod Talorchestia margaritae (Amphipoda: Talitridae and its relationship with the ecology of the species. T. margaritae, an endemic species inhabiting Venezuelan coasts, plays an important ecological role in plant and animal decomposition. To understand this issue in some animal groups, especially small ones, lipid composition analysis has been an interesting tool to describe their trophic relationships and food preferences. In order to assess this and visualize the components of their diet, we determined the lipid composition differences between males and females and among age classes in this species. Two sandy beaches were selected: Mangle Quemao and Las Mercedes de Paparo, from which sand samples of known volume were collected at the supralittoral area in 2007. Organisms were separated by age and sex classes, and their size, weight, density, biomass, total lipids (TL, lipid classes and fatty acid markers present in their tissues were determined. The sizes were similar for all age classes between the two locations, while the weights were higher for Mangle Quemao. The TL and lipid classes showed similar proportions between sexes, age classes and locations (TL: 3

  6. Effect of zinc-enriched natural sediments, in isolated and microcosm models, on three species of benthic invertebrates

    International Nuclear Information System (INIS)

    Galar Martinez, Marcela; Martinez-Tabche, Laura; Sanchez-Hidalgo, Eugenia; Lopez Lopez, Eugenia

    2006-01-01

    Availability of toxic in aquatic bodies is limited by the physicochemical characteristics of sediments and water, as well as by the interactions between the different xenobiotics and inhabits species. The aim of this work was to relate the effect produced by zinc (Zn) spiked in sediments of the Ignacio Ramirez dam (PIR), in isolated and microcosm models, on ATP concentration of three benthic organisms with the metal biodisponibility. The selected species were a crustacean, an annelid and a mollusk: Hyalella azteca (Amphipoda: Hyalellidae), Limnodrilus hoffmeisteri (Oligochaeta: Tubificidae) and Stagnicola attenuata (Basommatophora: Lymnaeidae), species that are found at high proportions in the reservoir and use different spaces in the benthos. Samples of sediments and organisms were collected from the PIR during the dry season (February of 1999). Metal concentration (Zn, Fe, Cu and Ni), pH, texture, particle size, total nitrogen and organic matter were determined in sediments. Sublethal studies were carried out using two types of static systems (isolated and in microcosm organisms). Both models contained PIR sediments enriched with Zn (nominal concentration of 0.8129 mg/kg) and synthetic water in a proportion of 1:4. The test organisms were added to the systems once the equilibrium was reached (2 hr) considering the biomass quantity with respect to volume (1.0 g of organism by each 100 ml of water:sediment). After 0, 12, 24, 36, 48 and 72 hr of exposure, samples of sediment and hydrobionts were taken, and Zn content was quantified by atomic absorption. ATP concentration was also determined in organisms. The effect produced by natural sediments spiked with Zn is increased by the presence of more than one specie in the system (microcosm). With respect to Zn levels, two of the organisms (L. hoffmeisteri y S. attenuata) tend to lose this metal in isolated and microcosm models, probably as a regulation strategy in its accumulation, as well as Fe presence in the

  7. Toxicity evaluation of a conservation effects assessment program watershed, Beasley Lake, in the Mississippi Delta, USA

    Science.gov (United States)

    Beasley Lake was assessed monthly in 2005 for biological impairment from 17 historic and current-use pesticides in water and leaf litter using Hyalella azteca (Saussure). Sixteen pesticides were detected in both water and leaf litter with peak detections in spring and summer. Detections ranged fro...

  8. Phototoxicity of TiO2 nanoparticles to a freshwater benthic amphipod: are benthic systems at risk?

    Science.gov (United States)

    This study investigated phototoxicity of TiO2 nanoparticles (nano-TiO2) to a freshwater benthic amphipod (Hyalella azteca) using 48-h and 96-h bioassays. Thorough monitoring of particle interactions with exposure media (Lake Superior water, LSW) and the surface of organisms was p...

  9. Toxicity of fluoride to aquatic species and evaluation of toxicity modifying factors.

    Science.gov (United States)

    Pearcy, Krysta; Elphick, James; Burnett-Seidel, Charlene

    2015-07-01

    The present study was performed to investigate the toxicity of fluoride to a variety of freshwater aquatic organisms and to establish whether water quality variables contribute substantively to modifying its toxicity. Water hardness, chloride, and alkalinity were tested as possible toxicity modifying factors for fluoride using acute toxicity tests with Hyalella azteca and Oncorhynchus mykiss. Chloride appeared to be the major toxicity modifying factor for fluoride in these acute toxicity tests. The chronic toxicity of fluoride was evaluated with a variety of species, including 3 fish (Pimephales promelas, O. mykiss, and Salvelinus namaycush), 3 invertebrates (Ceriodaphnia dubia, H. azteca, and Chironomus dilutus), 1 plant (Lemna minor), and 1 alga (Pseudokirchneriella subcapitata). Hyalella azteca was the most sensitive species overall, and O. mykiss was the most sensitive species of fish. The role of chloride as a toxicity modifying factor was inconsistent between species in the chronic toxicity tests. © 2015 SETAC.

  10. NA phylogeny of Ryukyus Leucothoidae (Crustacea: Amphipoda)

    NARCIS (Netherlands)

    White, K.N.; Reimer, J.D.

    2012-01-01

    Commensal leucothoid amphipods collected from sponges, ascidians, and coral rubble from the Ryukyu Archipelago, Japan, were investigated using nuclear 18S ribosomal DNA sequences. Analysis of sequences from 21 species in three genera supported the current morphological species designations and the

  11. Toxicological Effects of Military Smokes and Obscurants on Aquatic Threatened and Endangered Species

    Science.gov (United States)

    2008-11-10

    toxicity WSF water soluble fractions YCT Yeast -Cereal Leaves – Trout xii DRAFT version 2 ACKNOWLEDGMENTS The authors thank the Strategic...Before testing, organisms were fed a diet of Pseudokirchneriella subcapitata and Yeast -Cereal Leaves-Trout Chow (YCT) mixture daily at rates recommended... Brewer -Swarz S, and Thoeny WT (1997) A reformulated, reconstituted water for testing the freshwater amphipod, Hyalella azteca. Environ Toxicol & Chem 16

  12. Preparation and characterization of a hetero functional system of gold nanoparticles labeled with 99mTc and conjugated to the sequence Arg-Gly-Asp for detection in vivo of angio genesis and evaluation of their toxicity in Hyalella aztec

    International Nuclear Information System (INIS)

    Morales A, E.

    2012-01-01

    96 ± 2% without post-labeling purification. 99m Tc-HYNIC-G GC-AuNP-RGD showed specific recognition for α v β 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. 99m Tc-HYNIC-G GC-AuNP-RGD demonstrates properties suitable for use as a new target-specific agent for molecular imaging of tumor α v β 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 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)

  13. Efecto de sedimentos naturales enriquecidos con zinc, en modelos aislados y en microcosmos, sobre tres especies de invertebrados bentónicos

    Directory of Open Access Journals (Sweden)

    Marcela Galar Martínez

    2006-06-01

    y S. attenuata tienden a perder este metal tanto en sistemas aislados como en microcosmos, probablemente como estrategia de regulación en la acumulación del mismo, así como debido a la presencia de Fe en los sedimentos del embalse. Sin embargo, H. azteca mantiene sus niveles de Zn constantes durante todo el experimento, ya que es posible que la tasa de captación sea tan baja que no requiera otro tipo de mecanismo de regulación. Por otra parte se observó una disminución de ATP tanto en gusanos como en anfípodos expuestos a ambos sistemas a todos los tiempos de exposición; posiblemente los metales que se encuentran en los sedimentos interfieren con las enzimas encargadas de la producción energética por unión a grupos SH. Esta biomolécula se incrementó en el caracol en microcosmos a todos los tiempos de exposición y en sistemas aislados al final del experimento, probablemente debido a mecanismos compensatorios y al consumo reducido de energía que muestran los moluscos frente al estrés generado por la presencia de metales pesados.Effect of zinc-enriched sediments, in open and isolated systems, on three species of benthonic invertebrates. Availability of toxics in aquatic bodies is limited by the physicochemical characteristics of sediments and water, as well as by the interactions between the different xenobiotics and inhabits species. The aim of this work was to relate the effect produced by zinc (Zn spiked in sediments of the Ignacio Ramírez dam (PIR, in isolated and microcosms models, on ATP concentration of three benthic organisms with the metal biodisponibility. The selected species were a crustacean, an annelid and a mollusk: Hyalella azteca (Amphipoda: Hyalellidae, Limnodrilus hoffmeisteri (Oligochaeta: Tubificidae and Stagnicola attenuata (Basommatophora: Lymnaeidae, species that are found at high proportions in the reservoir and use different spaces in the benthos. Samples of sediments and organisms were collected from the PIR during the dry

  14. Androgen metabolism in invertebrates and its modulation by xenoandrogens: a comparative study.

    Science.gov (United States)

    Janer, G; Leblanc, G A; Porte, C

    2005-04-01

    Marisa cornuarietis (Mollusc), Hyalella azteca (Crustacean), and Paracentrotus lividus (Echinoderm) demonstrated the ability to metabolize androgens through different pathways catalyzed by 5alpha-reductases (5alpha-R), hydroxysteroid dehydrogenases (HSD), hydroxylases, sulfotransferases (SULT), and fatty-acid acyl-CoA acyltransferases (ATAT). Interspecies differences and tissue-specific distribution of those enzymatic activities were observed. Xenobiotics, such as triphenyltin, tributyltin, and fenarimol, interfered with some of the pathways studied, namely, testosterone sulfation, testosterone esterification, and 5alpha-R activity. The work evidenced different sensitivity of those pathways to androgenic compounds, together with interphyla differences in androgen metabolism.

  15. Addition of contaminant bioavailability and species susceptibility to a sediment toxicity assessment: Application in an urban stream in China

    International Nuclear Information System (INIS)

    Li, Huizhen; Sun, Baoquan; Chen, Xin; Lydy, Michael J.; You, Jing

    2013-01-01

    Sediments collected from an urban creek in China exhibited high acute toxicity to Hyalella azteca with 81.3% of sediments being toxic. A toxic unit (TU) estimation demonstrated that the pyrethroid, cypermethrin, was the major contributor to toxicity. The traditional TU approach, however, overestimated the toxicity. Reduced bioavailability of sediment-associated cypermethrin due to sequestration explained the overestimation. Additionally, antagonism among multiple contaminants and species susceptibility to various contaminants also contributed to the unexpectedly low toxicity to H. azteca. Bioavailable TUs derived from the bioavailability-based approaches, Tenax extraction and matrix-solid phase microextraction (matrix-SPME), showed better correlations with the noted toxicity compared to traditional TUs. As the first successful attempt to use matrix-SPME for estimating toxicity caused by emerging insecticides in field sediment, the present study found freely dissolved cypermethrin concentrations significantly improved the prediction of sediment toxicity to H. azteca compared to organic carbon normalized and Tenax extractable concentrations. Highlights: •Over 80% sediments from an urban stream in China were acutely toxic to H. azteca. •Toxic unit analysis showed cypermethrin was the major contributor to toxicity. •The traditional toxic unit approach overestimated sediment toxicity. •Reduced bioavailability was the reason for overestimating sediment toxicity. •Freely dissolved cypermethrin concentrations greatly improved toxicity prediction. -- Field sediment toxicity caused by current-use pesticides could be more accurately evaluated by incorporating bioavailability measurements into the toxic unit analysis

  16. Nickel toxicity to benthic organisms: The role of dissolved organic carbon, suspended solids, and route of exposure.

    Science.gov (United States)

    Custer, Kevin W; Hammerschmidt, Chad R; Burton, G Allen

    2016-01-01

    Nickel bioavailability is reduced in the presence of dissolved organic carbon (DOC), suspended solids (TSS), and other complexing ligands; however, no studies have examined the relative importance of Ni exposure through different compartments (water, sediment, food). Hyalella azteca and Lymnaea stagnalis were exposed to Ni-amended water, sediment, and food, either separately or in combination. Both organisms experienced survival and growth effects in several Ni compartment tests. The DOC amendments attenuated L. stagnalis Ni effects (survival, growth, and (62)Ni bioaccumulation), and presence of TSS exposures demonstrated both protective and synergistic effects on H. azteca and L. stagnalis. (62)Ni trophic transfer from food to H. azteca and L. stagnalis was negligible; however, bioaccumulating (62)Ni was attributed to (62)Ni-water ((62)Ni flux from food), (62)Ni-TSS, and (62)Ni-food. Overall, H. azteca and L. stagnalis Ni compartment toxicity increased in the following order: Ni-water > Ni-sediment > Ni-all (water, sediment, food) > Ni-food. Copyright © 2015 Elsevier Ltd. All rights reserved.

  17. Una principessa azteca: Tecuichpotzin Ichcaxochitzin – Isabel de Moctezuma

    Directory of Open Access Journals (Sweden)

    Rosa Maria Grillo

    2016-12-01

    Full Text Available In the framework of the ‘gender studies’ dedicated to forgotten women in history, a prominent place is occupied by Tecuichpotzin Ichcaxochitzin (“Cotton flower, the revered daughter of the lord”   daughter of Moctezuma II, was probably born at the end of the first decade of the sixteenth century. Baptized as Isabel de Moctezuma, she lived a life straddling two worlds and two eras: daughter and wife of kings, repudiated by Cortés, she is sometimes described as the anti Malinche, loyal to her people but perfectly integrated in the colonial system. This paper will compare different sources – historical chronicles of that time and subsequent periods, historical fiction   in order to provide a credible profile and to correctly interpret such contradictory comments and opinions.

  18. Taxonomic features and identification of Oxycephalidae (Platysceloidea, Physocephalata, Hyperiidea, Amphipoda)

    Digital Repository Service at National Institute of Oceanography (India)

    Nair, K.K.C.

    of the species. Taxonomy of the family is discussed with notes on inter- and intra-specific variations. Geographical distribution, ecophenotypic variations and biology of the species involved are mentioned. A detailed bibliographic account on the family is also...

  19. Comparison of oostegite shapes in some gammaroidean species (Crustacea: Amphipoda)

    NARCIS (Netherlands)

    Steele, D.H.

    1990-01-01

    Within the superfamily Gammaroidea oostegites vary from broad (primitive) to narrow (advanced). Broad oostegites are found in members of the Acanthogammaridae, Macrohectopidae and a few of the Gammaridae. Most species of the family Gammaridae have broad anterior oostegites and narrow posterior ones.

  20. Epigean freshwater Gammaridae (Crustacea, Amphipoda) from La Gomera (Canary Islands)

    NARCIS (Netherlands)

    Beyer, Gabriele; Stock, Jan H.

    1994-01-01

    Description of two new species of freshwater amphipods from La Gomera (Canary Islands), both found in the higher parts of the island: Chaetogammarus chaetocerus n. sp. and Rhipidogammarus gomeranus n. sp. Both species have distinct Afro- Iberian relationships.

  1. Metalycaea globosa stephensen, a valid species of Oxycephalidae (Amphipoda, Hyperiidea)

    Digital Repository Service at National Institute of Oceanography (India)

    Nair

    stream_size 6 stream_content_type text/plain stream_name J_Plankton_Res_15_1171.pdf.txt stream_source_info J_Plankton_Res_15_1171.pdf.txt Content-Encoding ISO-8859-1 Content-Type text/plain; charset=ISO-8859-1 ...

  2. Acute and chronic toxicity of boron to a variety of freshwater organisms.

    Science.gov (United States)

    Soucek, David J; Dickinson, Amy; Koch, Brian T

    2011-08-01

    Boron enters the aquatic environment from various sources, including weathering of borates, sewage effluents, coal combustion, use of cleaning compounds, and agrochemicals. The present study was designed to generate data on acute and chronic boron toxicity in support of an update of water quality standards in Illinois, USA. We examined the acute toxicity of boron to eight different freshwater organisms including a fish, an insect, two crustaceans, and four bivalve mollusks. To our knowledge, this is the first study to present data on the toxicity of boron to freshwater mollusks. We also sought to clarify whether hardness or pH affect boron toxicity to aquatic life, and to quantify chronic effect levels in two freshwater species. Sensitivity among the various species ranged widely, with the fathead minnow (Pimephales promelas) being the most sensitive. Neither pH nor hardness had a consistent effect on acute boron toxicity to two crustaceans (Ceriodaphnia dubia and Hyalella azteca), but we observed evidence that chloride reduces boron toxicity to H. azteca. The fathead minnow, while more acutely sensitive than the other species, had a lower acute to chronic ratio than did H. azteca, which had reduced reproduction at 13 mg/L. While we do not know the extent to which the eight tested species represent the range of sensitivities of native but untested species in Illinois, the current water quality standard for Illinois (1 mg/L) is conservative with regard to the native species tested thus far. Copyright © 2011 SETAC.

  3. Subcatchment deltas and upland features influence multiscale aquatic ecosystem recovery in damaged landscapes.

    Science.gov (United States)

    Kielstra, Brian W; Arnott, Shelley E; Gunn, John M

    2017-12-01

    Assessing biological recovery in damaged aquatic environments requires the consideration of multiple spatial and temporal scales. Past research has focused on assessing lake recovery from atmospheric or catchment disturbance at regional or catchment levels. Studies have also rarely considered the influences of adjacent terrestrial characteristics on within-lake habitats, such as subcatchment delta confluences. We used Hyalella azteca, a ubiquitous freshwater amphipod, as a sensitive indicator to assess the importance of local subcatchment scale factors in the context of multiscale lake recovery within the metal mining region of Sudbury, Canada following a period of major reductions in atmospheric pollution. At the regional scale, data from repeated surveys of 40 lakes showed higher probabilities of H. azteca occurrence with higher lake water conductivity, alkalinity, and pH and lower metal concentrations. The importance of metals decreased through time and the importance of higher conductivity, alkalinity, and pH increased. At the subcatchment scale, a subset of six lakes sampled across a colonization gradient revealed higher H. azteca abundances at subcatchment delta sites than non-delta sites in early colonization stages, and that abundance at delta sites was correlated with both within-lake habitat and terrestrial subcatchment characteristics. For example, wetland cover reduced the strength of positive associations between H. azteca abundance and macrophyte density. A single lake from this subset also revealed higher abundances at delta sites associated with higher concentrations of terrestrial organic matter and larger subcatchments. Our results demonstrate that factors affecting recovery can change with the scale of study, and that managing terrestrial-aquatic linkages is important for facilitating recovery processes within damaged lake ecosystems. © 2017 by the Ecological Society of America.

  4. Trait-based modelling of bioaccumulation by freshwater benthic invertebrates.

    Science.gov (United States)

    Sidney, Livia Alvarenga; Diepens, Noël J; Guo, Xiaoying; Koelmans, Albert A

    2016-07-01

    Understanding the role of species traits in chemical exposure is crucial for bioaccumulation and toxicity assessment of chemicals. We measured and modelled bioaccumulation of polychlorinated biphenyls (PCBs) in Chironomus riparius, Hyalella azteca, Lumbriculus variegatus and Sphaerium corneum. We used a battery test procedure with multiple enclosures in one aquarium, which maximized uniformity of exposure for the different species, such that the remaining variability was due mostly to species traits. The relative importance of uptake from either pore water or sediment ingestion was manipulated by using 28 d aged standard OECD sediment with low (1%) and medium (5%) OM content and 13 months aged sediment with medium OM (5%) content. Survival was ≥76% and wet weight increased for all species. Reproduction of H. azteca and weight gain of H. azteca and S. corneum were significantly higher in the medium OM aged sediments than in other sediments, perhaps due to a more developed microbial community (i.e., increase in food resources). Biota-sediment accumulation factors (BSAF) ranged from 3 to 114, depending on species and PCB congener, with C. riparius (3-10)Azteca (5-114), thus challenging the presumed value of 1-2 typically employed in ecological risk assessment schemes. BSAFs for freshwater taxonomic groups were compared with their marine counterparts and showed overlapping values. The dynamic bioaccumulation model with species-specific bioaccumulation parameters fitted well to the experimental data and showed that bioaccumulation parameters were depended on species traits. Enclosure-based battery tests and mechanistic BSAF models are expected to improve the quality of the exposure assessment in whole sediment toxicity tests. Copyright © 2016 Elsevier B.V. All rights reserved.

  5. Phototoxicity of TiO2 nanoparticles to a freshwater benthic amphipod: Are benthic systems at risk?

    International Nuclear Information System (INIS)

    Li, Shibin; Wallis, Lindsay K.; Ma, Hongbo; Diamond, Stephen A.

    2014-01-01

    This study investigated phototoxicity of TiO 2 nanoparticles (nano-TiO 2 ) to a freshwater benthic amphipod (Hyalella azteca) using 48-h and 96-h bioassays. Thorough monitoring of particle interactions with exposure media (Lake Superior water, LSW) and the surface of organisms was performed using dynamic light scattering, UV/Vis spectroscopy, and Scanning Electron Microscopy. Large agglomeration and sedimentation (> 77%) in LSW was observed after 0.5 h. A simulated solar radiation (SSR)-favored surface attachment of nanoparticles was observed, indicating enhanced phototoxicity with the increased attachment. A 96-h median lethal concentration (LC50) of 29.9 mg/L in H. azteca was calculated, with a daily 4-h UV exposure of 2.2 W/m 2 . Phototoxicity of nano-TiO 2 under SSR had a 21-fold increase as compared to that under ambient laboratory light. This phototoxicity was also dependent on UV dose, with calculated LC50s around 22.9 (95% CI, 20.5–23.3) Wh/m 2 when exposed to 20 mg/L nano-TiO 2 . Also, H. azteca exhibited negative phototaxis in the presence of shelters, indicating that other factors might play a role in environmental systems. Finally, the environmental implications of nano-TiO 2 to benthic organisms were illustrated, emphasizing the importance of various environmental factors in the ultimate phototoxicity. This increased phototoxicity and its complex interactions with various environmental factors suggest further investigations are needed for future risk assessment of photoactive nanomaterials to benthic organisms. - Graphical abstract: Display Omitted - Highlights: •Large aggregation of TiO 2 nanoparticles in Lake Superior water was observed. •Phototoxicity was dependent on the dose of both solar radiation and nanoparticle. •A solar radiation favored surface attachment of nanoparticles was observed. •Hyalella azteca exhibited negative phototaxis in the presence of shelters. •Factors influencing phototoxicity in the real environment were

  6. Acute and chronic toxicity testing of bisphenol A with aquatic invertebrates and plants.

    Science.gov (United States)

    Mihaich, Ellen M; Friederich, Urs; Caspers, Norbert; Hall, A Tilghman; Klecka, Gary M; Dimond, Stephen S; Staples, Charles A; Ortego, Lisa S; Hentges, Steven G

    2009-07-01

    Bisphenol A (BPA, 4,4'-isopropylidine diphenol) is a commercially important chemical used primarily as an intermediate in the production of polycarbonate plastic and epoxy resins. Extensive effect data are currently available, including long-term studies with BPA on fish, amphibians, crustaceans, and mollusks. The aim of this study was to perform additional tests with a number of aquatic invertebrates and an aquatic plant. These studies include acute tests with the midge (Chironomus tentans) and the snail (Marisa cornuarietis), and chronic studies with rotifers (Brachionus calyciflorus), amphipods (Hyalella azteca), and plants (Lemna gibba). The effect data on different aquatic invertebrate and plant species presented in this paper correspond well with the effect and no-effect concentrations (NOECs) available from invertebrate studies in the published literature and are within the range found for other aquatic species tested with BPA.

  7. Invasive alien species water hyacinth Eichhornia crassipes as abode for macroinvertebrates in hypertrophic Ramsar Site, Lake Xochimilco, Mexico.

    Science.gov (United States)

    Rocha-Ramirez, A; Robles-Valderrama, E; Ramirez-Flores, E

    2014-11-01

    This paper presents information on the density, diversity and functional feeding groups of macroinvertebrate assemblages associated with water hyacinth in Antiguo Canal Cuemanco, part of Lake Xochimilco in Mexico City. Rare (low frequency and density) and dominant (high frequency and density) taxa prevailed in the assemblages, with the most predominant being Hyalella azteca, Chironomus plumosus and Ischnura denticollis. Nonmetric Multidimensional Scaling confirmed two climatic seasons: warm-rainy and cold-dry; the former with the highest diversity and density of taxa. Canonical Correspondence Analysis showed that conductivity, nitrates and turbidity explained the density variations of taxa. Antiguo Canal Cuemanco waters are spatially homogeneous with the characteristics of hypertrophic shallow lakes, inhabited by scrapers and gathering-collectors. The species found were tolerant to organic pollution.

  8. In situ exposures using caged organisms: a multi-compartment approach to detect aquatic toxicity and bioaccumulation

    International Nuclear Information System (INIS)

    Burton, G. Allen; Greenberg, Marc S.; Rowland, Carolyn D.; Irvine, Cameron A.; Lavoie, Daniel R.; Brooker, John A.; Moore, Laurie; Raymer, Delia F.N.; McWilliam, Ruth A.

    2005-01-01

    An in situ toxicity and bioaccumulation assessment approach is described to assess stressor exposure and effects in surface waters (low and high flow), the sediment-water interface, surficial sediments and pore waters (including groundwater upwellings). This approach can be used for exposing species, representing major functional and taxonomic groups. Pimephales promelas, Daphnia magna, Ceriodaphnia dubia, Hyalella azteca, Hyalella sp., Chironomus tentans, Lumbriculus variegatus, Hydra attenuatta, Hexagenia sp. and Baetis tibialis were successfully used to measure effects on survival, growth, feeding, and/or uptake. Stressors identified included chemical toxicants, suspended solids, photo-induced toxicity, indigenous predators, and flow. Responses varied between laboratory and in situ exposures in many cases and were attributed to differing exposure dynamics and sample-processing artifacts. These in situ exposure approaches provide unique assessment information that is complementary to traditional laboratory-based toxicity and bioaccumulation testing and reduce the uncertainties of extrapolating from the laboratory to field responses. - In situ exposures provide unique information that is complementary to traditional lab-based toxicity results

  9. Methylmercury bioaccumulation in stream food webs declines with increasing primary production

    Science.gov (United States)

    Walters, David; D.F. Raikow,; C.R. Hammerschmidt,; M.G. Mehling,; A. Kovach,; J.T. Oris,

    2015-01-01

    Opposing hypotheses posit that increasing primary productivity should result in either greater or lesser contaminant accumulation in stream food webs. We conducted an experiment to evaluate primary productivity effects on MeHg accumulation in stream consumers. We varied light for 16 artificial streams creating a productivity gradient (oxygen production =0.048–0.71 mg O2 L–1 d–1) among streams. Two-level food webs were established consisting of phytoplankton/filter feeding clam, periphyton/grazing snail, and leaves/shredding amphipod (Hyalella azteca). Phytoplankton and periphyton biomass, along with MeHg removal from the water column, increased significantly with productivity, but MeHg concentrations in these primary producers declined. Methylmercury concentrations in clams and snails also declined with productivity, and consumer concentrations were strongly correlated with MeHg concentrations in primary producers. Heterotroph biomass on leaves, MeHg in leaves, and MeHg in Hyalella were unrelated to stream productivity. Our results support the hypothesis that contaminant bioaccumulation declines with stream primary production via the mechanism of bloom dilution (MeHg burden per cell decreases in algal blooms), extending patterns of contaminant accumulation documented in lakes to lotic systems.

  10. Identifying primary stressors impacting macroinvertebrates in the Salinas River (California, USA): Relative effects of pesticides and suspended particles

    International Nuclear Information System (INIS)

    Anderson, B.S.; Phillips, B.M.; Hunt, J.W.; Connor, V.; Richard, N.; Tjeerdema, R.S.

    2006-01-01

    Laboratory dose-response experiments with organophosphate and pyrethroid pesticides, and dose-response experiments with increasing particle loads were used to determine which of these stressors were likely responsible for the toxicity and macroinvertebrate impacts previously observed in the Salinas River. Experiments were conducted with the amphipod Hyalella azteca, the baetid mayfly Procloeon sp., and the midge Chironomus dilutus (Shobanov, formerly Chironomus tentans). The results indicate the primary stressor impacting H. azteca was pesticides, including chlorpyrifos and permethrin. The mayfly Procloeon sp. was sensitive to chlorpyrifos and permethrin within the range of concentrations of these pesticides measured in the river. Chironomus dilutus were sensitive to chlorpyrifos within the ranges of concentrations measured in the river. None of the species tested were affected by turbidity as high as 1000 NTUs. The current study shows that pesticides are more important acute stressors of macroinvertebrates than suspended sediments in the Salinas River. - Pesticides are the primary stressor impacting macroinvertebrates in sections of the lower Salinas River

  11. Identifying primary stressors impacting macroinvertebrates in the Salinas River (California, USA): Relative effects of pesticides and suspended particles

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, B.S. [Department of Environmental Toxicology, University of California, Davis, CA 95616 (United States)]. E-mail: anderson@ucdavis.edu; Phillips, B.M. [Department of Environmental Toxicology, University of California, Davis, CA 95616 (United States); Hunt, J.W. [Department of Environmental Toxicology, University of California, Davis, CA 95616 (United States); Connor, V. [Division of Water Quality, State Water Resources Control Board, 1001 I. Street, Sacramento, CA 95814 (United States); Richard, N. [Division of Water Quality, State Water Resources Control Board, 1001 I. Street, Sacramento, CA 95814 (United States); Tjeerdema, R.S. [Department of Environmental Toxicology, University of California, Davis, CA 95616 (United States)

    2006-06-15

    Laboratory dose-response experiments with organophosphate and pyrethroid pesticides, and dose-response experiments with increasing particle loads were used to determine which of these stressors were likely responsible for the toxicity and macroinvertebrate impacts previously observed in the Salinas River. Experiments were conducted with the amphipod Hyalella azteca, the baetid mayfly Procloeon sp., and the midge Chironomus dilutus (Shobanov, formerly Chironomus tentans). The results indicate the primary stressor impacting H. azteca was pesticides, including chlorpyrifos and permethrin. The mayfly Procloeon sp. was sensitive to chlorpyrifos and permethrin within the range of concentrations of these pesticides measured in the river. Chironomus dilutus were sensitive to chlorpyrifos within the ranges of concentrations measured in the river. None of the species tested were affected by turbidity as high as 1000 NTUs. The current study shows that pesticides are more important acute stressors of macroinvertebrates than suspended sediments in the Salinas River. - Pesticides are the primary stressor impacting macroinvertebrates in sections of the lower Salinas River.

  12. Microplastic Effect Thresholds for Freshwater Benthic Macroinvertebrates

    Science.gov (United States)

    2018-01-01

    Now that microplastics have been detected in lakes, rivers, and estuaries all over the globe, evaluating their effects on biota has become an urgent research priority. This is the first study that aims at determining the effect thresholds for a battery of six freshwater benthic macroinvertebrates with different species traits, using a wide range of microplastic concentrations. Standardized 28 days single species bioassays were performed under environmentally relevant exposure conditions using polystyrene microplastics (20–500 μm) mixed with sediment at concentrations ranging from 0 to 40% sediment dry weight (dw). Microplastics caused no effects on the survival of Gammarus pulex, Hyalella azteca, Asellus aquaticus, Sphaerium corneum, and Tubifex spp. and no effects were found on the reproduction of Lumbriculus variegatus. No significant differences in growth were found for H. azteca, A. aquaticus, S. corneum, L. variegatus, and Tubifex spp. However, G. pulex showed a significant reduction in growth (EC10 = 1.07% sediment dw) and microplastic uptake was proportional with microplastic concentrations in sediment. These results indicate that although the risks of environmentally realistic concentrations of microplastics may be low, they still may affect the biodiversity and the functioning of aquatic communities which after all also depend on the sensitive species. PMID:29337537

  13. Assessing sediment contamination using six toxicity assays

    Directory of Open Access Journals (Sweden)

    Allen G. BURTON Jr.

    2001-08-01

    Full Text Available An evaluation of sediment toxicity at Lake Orta, Italy was conducted to compare a toxicity test battery of 6 assays and to evaluate the extent of sediment contamination at various sediment depths. Lake Orta received excessive loadings of copper and ammonia during the 1900’s until a large remediation effort was conducted in 1989-90 using lime addition. Since that time, the lake has shown signs of a steady recovery of biological communities. The study results showed acute toxicity still exists in sediments at a depth of 5 cm and greater. Assays that detected the highest levels of toxicity were two whole sediment exposures (7 d using Hyalella azteca and Ceriodaphnia dubia. The MicrotoxR assay using pore water was the third most sensitive assay. The Thamnotox, Rototox, Microtox solid phase, and Seed Germination-Root Elongation (pore and solid phase assays showed occasional to no toxicity. Based on similarity of responses and assay sensitivity, the two most useful assays were the C. dubia (or H. azteca and Microtox pore water. These assays were effective at describing sediment toxicity in a weight-of-evidence approach.

  14. Toxicological evaluation of a lake ecosystem contaminated with crude oil

    International Nuclear Information System (INIS)

    Twigg, D.; Ramey, B.

    1995-01-01

    Winona Lake on the Daniel Boone National Forest in Powell County, Kentucky, was used from the mid 1950's to 1987 as a water source for water-injection oil drilling and as a brine disposal site. The lake was contaminated with excessive amounts of crude oil. A multi phase investigation was conducted, including chemical analysis of water and sediment, water toxicity tests using a cladoceran, Ceriodaphnia dubia, sediment toxicity tests using an amphipod, Hyalella azteca, and a faunal survey of the communities of the lake and stream both above and below the lake. The sediment was laden with petroleum hydrocarbons (4.1 parts per thousand), while the water showed no contamination. The C dubia test results showed no significant water toxicity. The contaminated sediment adjacent to the dam produced 75% mortality in H. azteca. The faunal survey indicated little or no impact on the upstream and downstream communities but the lake community was highly impacted, especially the benthos. Pollution tolerant Chaoborus sp. were the only organisms collected from sediment samples dredged from the lake. Contamination was limited to the sediment within the lake but the impact on the entire lake community was severe

  15. Occurrence and potential toxicity of pyrethroids and other insecticides in bed sediments of urban streams in central Texas

    Energy Technology Data Exchange (ETDEWEB)

    Hintzen, Emily P. [Department of Environmental Studies, Baylor University, Waco, TX 76798 (United States); Lydy, Michael J. [Fisheries and Illinois Aquaculture Center, and Department of Zoology, Southern Illinois University, Carbondale, IL 62091 (United States); Belden, Jason B. [Department of Zoology, Oklahoma State University, 430 Life Science West, Stillwater, OK 74078 (United States)], E-mail: jbelden@okstate.edu

    2009-01-15

    Despite heavy insecticide usage in urban areas, only a few studies have investigated the impact of current-use insecticides on benthic invertebrates in urban streams. The objective of this study was to measure the presence and concentration of current-use pesticides in sediments of residential streams in central Texas. Additionally, toxicity of these sediments to Hyalella azteca was evaluated. Sediment samples were collected from several sites in urban streams over the course of a year, of which, 66% had greater than one toxic unit (TU) of insecticide. Bifenthrin was the greatest contributor accounting for 65% of the TUs, and sediment toxicity to H. azteca correlated with the magnitude of total insecticides and bifenthrin TUs. The results of this study further raise concerns over the environmental consequences posed by many current-use insecticides, especially pyrethroids, in urban settings. - This study examined the presence of insecticides in Texas stream sediments as a model for evaluating the potential impact of urban insecticide use in the Southern United States.

  16. Occurrence and potential toxicity of pyrethroids and other insecticides in bed sediments of urban streams in central Texas

    International Nuclear Information System (INIS)

    Hintzen, Emily P.; Lydy, Michael J.; Belden, Jason B.

    2009-01-01

    Despite heavy insecticide usage in urban areas, only a few studies have investigated the impact of current-use insecticides on benthic invertebrates in urban streams. The objective of this study was to measure the presence and concentration of current-use pesticides in sediments of residential streams in central Texas. Additionally, toxicity of these sediments to Hyalella azteca was evaluated. Sediment samples were collected from several sites in urban streams over the course of a year, of which, 66% had greater than one toxic unit (TU) of insecticide. Bifenthrin was the greatest contributor accounting for 65% of the TUs, and sediment toxicity to H. azteca correlated with the magnitude of total insecticides and bifenthrin TUs. The results of this study further raise concerns over the environmental consequences posed by many current-use insecticides, especially pyrethroids, in urban settings. - This study examined the presence of insecticides in Texas stream sediments as a model for evaluating the potential impact of urban insecticide use in the Southern United States

  17. Biogeochemical controls on the speciation and aquatic toxicity of vanadium and other metals in sediments from a river reservoir

    Energy Technology Data Exchange (ETDEWEB)

    Nedrich, Sara M.; Chappaz, Anthony; Hudson, Michelle L.; Brown, Steven S.; Burton, G. Allen

    2018-01-01

    Effects of hydrologic variability on reservoir biogeochemistry are relatively unknown, particularly for less studied metals like vanadium (V). Further, few studies have investigated the fate and effects of sediment-associated V to aquatic organisms in hydrologically variable systems. Our primary objective was to assess effects of hydrologic manipulation on speciation and toxicity of V (range: 635 to 1620 mg kg- 1) and other metals to Hyalella azteca and Daphnia magna. Sediments were collected from a reservoir located in a former mining area and microcosm experiments were conducted to emulate 7-day drying and inundation periods. Despite high sediment concentrations, V bioavailability remained low with no significant effects to organism survival, growth, or reproduction. The lack of V toxicity was attributed to reduced speciation (III, IV), non-labile complexation, and sorption to Al/Fe/Mn-oxyhydroxides. Zinc (Zn) increased in surface and porewater with inundation, for some sediments exceeding the U.S. EPA threshold for chronic toxicity. While no effects of Zn to organism survival or growth were observed, Zn body concentrations were negatively correlated with H. azteca growth. Results from this study indicate that V bioavailability and environmental risk is dependent on V-speciation, and V is less influenced by hydrologic variability than more labile metals such as Zn.

  18. A comparative study on androgen metabolism in three invertebrate species.

    Science.gov (United States)

    Janer, G; LeBlanc, G A; Porte, C

    2005-09-15

    A comparative approach was taken in this study to evaluate androgen (androstenedione and testosterone) metabolism in three invertebrate species: the gastropod Marisa cornuarietis, the amphipod Hyalella azteca, and the echinoderm Paracentrotus lividus. The existence of 17beta/3beta-hydroxysteroid dehydrogenase (HSD) and 5alpha-reductase catalyzed reactions was demonstrated in all three species. Androstenedione was primarily converted to 5alpha-androstanedione in M. cornuarietis, while it was primarily metabolized to testosterone in P. lividus and H. azteca. In addition, and consistent with vertebrate findings, tissue specific pathways and sexual dimorphism in androgen metabolism were observed. Namely, testosterone was metabolized to dihydrotestosterone in P. lividus gonads (via 5alpha-reductase), and metabolized to 4-androstene-3beta,17beta-diol in the digestive tube (via 3beta-hydroxysteroid dehydrogenase). Furthermore, the synthesis of 17beta-reduced metabolites of androstenedione (testosterone and dihydrotestosterone) was 3- to 4-fold higher in males of M. cornuarietis than in females. Organotin compounds, which have been shown to interfere with some aspects of androgen metabolism, had no major effect on testosterone metabolism in any of the three species. Fenarimol enhanced 5alpha-reductase-mediated catalysis in gonads of P. lividus. Overall, results demonstrate the ubiquity of some androgen biotransformation processes in invertebrates and reveals interphyla differences in androgen metabolic pathways, and different sensitivity of these pathways to some xenobiotics.

  19. Lead Speciation and Bioavailability in Apatite-Amended Sediments

    Directory of Open Access Journals (Sweden)

    Kirk G. Scheckel

    2011-01-01

    Full Text Available The in situ sequestration of lead (Pb in sediment with a phosphate amendment was investigated by Pb speciation and bioavailability. Sediment Pb in preamendment samples was identified as galena (PbS with trace amounts of absorbed Pb. Sediment exposed to atmospheric conditions underwent conversion to hydrocerussite and anglesite. Sediments mixed with apatite exhibited limited conversion to pyromorphite, the hypothesized end product. Conversion of PbS to pyromorphite is inhibited under reducing conditions, and pyromorphite formation appears limited to reaction with pore water Pb and PbS oxidation products. Porewater Pb values were decreased by 94% or more when sediment was amended with apatite. The acute toxicity of the sediment Pb was evaluated with Hyalella azteca and bioaccumulation of Pb with Lumbriculus variegatus. The growth of H. azteca may be mildly inhibited in contaminated sediment, with apatite-amended sediments exhibiting on average a higher growth weight by approximately 20%. The bioaccumulation of Pb in L. variegatus tissue decreased with increased phosphate loading in contaminated sediment. The study indicates limited effectiveness of apatite in sequestering Pb if present as PbS under reducing conditions, but sequestration of porewater Pb and stabilization of near-surface sediment may be a feasible and alternative approach to decreasing potential toxicity of Pb.

  20. Toxicity and bioaccumulation of sediment-associated contaminants using freshwater invertebrates: A review of methods and applications

    Science.gov (United States)

    Ingersoll, C.G.; Ankley, G.T.; Benoit, D.A.; Brunson, E.L.; Burton, G.A.; Dwyer, F.J.; Hoke, R.A.; Landrum, P.F.; Norberg-King, T. J.; Winger, P.V.

    1995-01-01

    This paper reviews recent developments in methods for evaluating the toxicity and bioaccumulation of contaminants associated with freshwater sediments and summarizes example case studies demonstrating the application of these methods. Over the past decade, research has emphasized development of more specific testing procedures for conducting 10-d toxicity tests with the amphipod Hyalella azteca and the midge Chironomus tentans. Toxicity endpoints measured in these tests are survival for H. azteca and survival and growth for C. tentans. Guidance has also been developed for conducting 28-d bioaccumulation tests with the oligochaete Lumbriculus variegatus, including determination of bioaccumulation kinetics for different compound classes. These methods have been applied to a variety of sediments to address issues ranging from site assessments to bioavailability of organic and inorganic contaminants using field-collected and laboratory-spiked samples. Survival and growth of controls routinely meet or exceed test acceptability criteria. Results of laboratory bioaccumulation studies with L. variegatus have been confirmed with comparisons to residues (PCBs, PAHs, DDT) present from synoptically collected field populations of oligochaetes. Additional method development is currently underway to develop chronic toxicity tests and to provide additional data-confirming responses observed in laboratory sediment tests with natural benthic populations.

  1. Transfers and transformations of zinc in flow-through wetland microcosms.

    Science.gov (United States)

    Gillespie, W B; Hawkins, W B; Rodgers, J H; Cano, M L; Dorn, P B

    1999-06-01

    Two microcosm-scale wetlands (570-liter containers) were integratively designed and constructed to investigate transfers and transformations of zinc associated with an aqueous matrix, and to provide future design parameters for pilot-scale constructed wetlands. The fundamental design of these wetland microcosms was based on biogeochemical principles regulating fate and transformations of zinc (pH, redox, etc.). Each wetland consisted of a 45-cm hydrosoil depth inundated with 25 cm of water, and planted with Scirpus californicus. Zinc ( approximately 2 mg/liter) as ZnCl2 was amended to each wetland for 62 days. Individual wetland hydraulic retention times (HRT) were approximately 24 h. Total recoverable zinc was measured daily in microcosm inflow and outflows, and zinc concentrations in hydrosoil and S. californicus tissue were measured pre- and post-treatment. Ceriodaphnia dubia and Pimephales promelas7-day aqueous toxicity tests were performed on wetland inflows and outflows, and Hyalella azteca whole sediment toxicity tests (10-day) were performed pre- and post-treatment. Approximately 75% of total recoverable zinc was transferred from the water column. Toxicity decreased from inflow to outflow based on 7-day C. dubia tests, and survival of H. azteca in hydrosoil was >80%. Data illustrate the ability of integratively designed wetlands to transfer and sequester zinc from the water column while concomitantly decreasing associated toxicity. Copyright 1999 Academic Press.

  2. Ensamble de crustáceos bentónicos en un lago salino tropical Benthic crustaceans assemblage in a tropical, saline lake

    Directory of Open Access Journals (Sweden)

    Ma. del Carmen Hernández

    2010-10-01

    Full Text Available El presente trabajo reconoce la composición, estructura y distribución espacial del ensamble de crustáceos bentónicos de Alchichica, un lago salino tropical ubicado en el extremo oriental del altiplano mexicano. El lago presenta una riqueza taxonómica de crustáceos bentónicos compuesta por 1 anfípodo (Hyalella azteca, 1 isópodo (Caecidotea williamsi y 2 ostrácodos (Limnocythere inopinata y Candona sp.. Comparada con otros lagos tropicales, la riqueza de especies es reducida. A pesar de lo anterior, es importante mencionar el grado elevado de endemismo representado por C. williamsi, recientemente descrita para el lago Alchichica; adicionalmente, es factible que tanto Candona como H. azteca sean especies nuevas y endémicas del lago. Los crustáceos bentónicos se distribuyen desde la zona litoral hasta la zona más profunda del lago (62 m con abundancias y riqueza taxonómica variables. Los ostrácodos fueron los crustáceos que con mayor frecuencia se recolectaron en el lago, en la zona litoral, en el talud, y en la zona profunda de la que son habitantes exclusivos. Los anfípodos constituyeron el segundo grupo en abundancia de la zona litoral y talud y estuvieron ausentes en la zona profunda. Los isópodos sólo se encuentran asociados a los depósitos de tufa, hábitat característico del lago que se extiende a lo largo del talud, por lo que con las técnicas de muestreo tradicional empleadas en el presente estudio no fueron capturados. En este ensamble de crustáceos predominan las especies de desarrollo directo y con posiciones tróficas que incluyen componentes herbívoros (H. azteca, omnívoros (C. williamsi y bacterívoros (L. inopinata y Candona sp..This work acknowledges the composition, structure and spatial distribution of the benthic crustaceans assemblage of Alchichica, a tropical saline lake located in the easternmost portion of the Mexican highlands. The benthic crustaceans' assemblage was comprised by 1 amphipod

  3. Specifically Designed Constructed Wetlands: A Novel Treatment Approach for Scrubber Wastewater

    Energy Technology Data Exchange (ETDEWEB)

    John H. Rodgers Jr; James W. Castle; Chris Arrington: Derek Eggert; Meg Iannacone

    2005-09-01

    A pilot-scale wetland treatment system was specifically designed and constructed at Clemson University to evaluate removal of mercury, selenium, and other constituents from flue gas desulfurization (FGD) wastewater. Specific objectives of this research were: (1) to measure performance of a pilot-scale constructed wetland treatment system in terms of decreases in targeted constituents (Hg, Se and As) in the FGD wastewater from inflow to outflow; (2) to determine how the observed performance is achieved (both reactions and rates); and (3) to measure performance in terms of decreased bioavailability of these elements (i.e. toxicity of sediments in constructed wetlands and toxicity of outflow waters from the treatment system). Performance of the pilot-scale constructed wetland treatment systems was assessed using two criteria: anticipated NPDES permit levels and toxicity evaluations using two sentinel toxicity-testing organisms (Ceriodaphnia dubia and Pimephales promelas). These systems performed efficiently with varied inflow simulations of FGD wastewaters removing As, Hg, and Se concentrations below NPDES permit levels and reducing the toxicity of simulated FGD wastewater after treatment with the constructed wetland treatment systems. Sequential extraction procedures indicated that these elements (As, Hg, and Se) were bound to residual phases within sediments of these systems, which should limit their bioavailability to aquatic biota. Sediments collected from constructed wetland treatment systems were tested to observe toxicity to Hyalella azteca or Chironomus tetans. Complete survival (100%) was observed for H. azteca in all cells of the constructed wetland treatment system and C. tentans had an average of 91% survival over the three treatment cells containing sediments. Survival and growth of H. azteca and C. tentans did not differ significantly between sediments from the constructed wetland treatment system and controls. Since the sediments of the constructed

  4. Testosterone conjugating activities in invertebrates: are they targets for endocrine disruptors?

    Science.gov (United States)

    Janer, G; Sternberg, R M; LeBlanc, G A; Porte, C

    2005-02-10

    Testosterone conjugation activities, microsomal acyltransferases and cytosolic sulfotransferases, were investigated in three invertebrate species, the gastropod Marisa cornuarietis, the amphipod Hyalella azteca, and the echinoderm Paracentrotus lividus. The goals of the study were to characterize steroid conjugation pathways in different invertebrate phyla and to assess the susceptibility of those processes to disruption by environmental chemicals. All three species exhibited palmitoyl-CoA: testosterone acyltransferase activity (ATAT) in the range of 100-510 pmol/min/mg protein. Despite similarities in specific activities, kinetic studies indicated that ATAT had a higher affinity for testosterone but a lower V(max) in M. cornuarietis than in P. lividus, and intermediate values were found for H. azteca. In contrast, the activity of testosterone sulfotransferase (SULT) was rather low (0.05-0.18 pmol/min/mg protein) in M. cornuarietis and H. azteca. The low activity precluded kinetic analyses and inhibition studies with these species. P. lividus digestive tube displayed high SULT activity (50-170 pmol/min/mg protein) at moderate testosterone concentrations, but was inhibited at high testosterone concentrations. The interference of model pollutants (triphenyltin (TPT), tributyltin (TBT), and fenarimol) with these conjugation pathways was investigated in vitro. Both TPT and TBT (100 microM) inhibited ATAT in P. lividus (68 and 42% inhibition, respectively), and appeared to act as non-competitive inhibitors. ATAT activity in M. cornuarietis was less affected by organotins, and a significant inhibition (20% inhibition) was detected only with TBT. Fenarimol (100 microM) did not affect ATAT in any of the species tested. Sulfation of testosterone was suppressed by the organotins as well as fenarimol when using cytosolic preparations from P. lividus. These results demonstrated the existence of interphyla differences in testosterone conjugation, and revealed that these

  5. Epimeria of the Southern Ocean with notes on their relatives (Crustacea, Amphipoda, Eusiroidea

    Directory of Open Access Journals (Sweden)

    Cédric d'Udekem d'Acoz

    2017-10-01

    Full Text Available The present monograph includes general systematic considerations on the family Epimeriidae, a revision of the genus Epimeria Costa in Hope, 1851 in the Southern Ocean, and a shorter account on putatively related eusiroid taxa occurring in Antarctic and sub-Antarctic seas. The former epimeriid genera Actinacanthus Stebbing, 1888 and Paramphithoe Bruzelius, 1859 are transferred to other families, respectively to the Acanthonotozomellidae Coleman & J.L. Barnard, 1991 and the herein re-established Paramphithoidae G.O. Sars, 1883, so that only Epimeria and Uschakoviella Gurjanova, 1955 are retained within the Epimeriidae Boeck, 1871. The genera Apherusa Walker, 1891 and Halirages Boeck, 1891, which are phylogenetically close to Paramphithoe, are also transferred to the Paramphithoidae. The validity of the suborder Senticaudata Lowry & Myers, 2013, which conflicts with traditional and recent concepts of Eusiroidea Stebbing, 1888, is questioned. Eight subgenera are recognized for Antarctic and sub-Antarctic species of the genus Epimeria: Drakepimeria subgen. nov., Epimeriella K.H. Barnard, 1930, Hoplepimeria subgen. nov., Laevepimeria subgen. nov., Metepimeria Schellenberg, 1931, Pseudepimeria Chevreux, 1912, Subepimeria Bellan-Santini, 1972 and Urepimeria subgen. nov. The type subgenus Epimeria, as currently defined, does not occur in the Southern Ocean. Drakepimeria species are superficially similar to the type species of the genus Epimeria: E. cornigera (Fabricius, 1779, but they are phylogenetically unrelated and substantial morphological differences are obvious at a finer level. Twenty-seven new Antarctic Epimeria species are described herein: Epimeria (Drakepimeria acanthochelon subgen. et sp. nov., E. (D. anguloce subgen. et sp. nov., E. (D. colemani subgen. et sp. nov., E. (D. corbariae subgen. et sp. nov., E. (D. cyrano subgen. et sp. nov., E. (D. havermansiana subgen. et sp. nov., E. (D. leukhoplites subgen. et sp. nov., E. (D. loerzae subgen. et sp. nov., E. (D. pandora subgen. et sp. nov., E. (D. pyrodrakon subgen. et sp. nov., E. (D. robertiana subgen. et sp. nov., Epimeria (Epimeriella atalanta sp. nov., Epimeria (Hoplepimeria cyphorachis subgen. et sp. nov., E. (H. gargantua subgen. et sp. nov., E. (H. linseae subgen. et sp. nov., E. (H. quasimodo subgen. et sp. nov., E. (H. xesta subgen. et sp. nov., Epimeria (Laevepimeria anodon subgen. et sp. nov., E. (L. cinderella subgen. et sp. nov., Epimeria (Pseudepimeria amoenitas sp. nov., E. (P. callista sp. nov., E. (P. debroyeri sp. nov., E. (P. kharieis sp. nov., Epimeria (Subepimeria adeliae sp. nov., E. (S. iota sp. nov., E. (S. teres sp. nov. and E. (S. urvillei sp. nov. The type specimens of E. (D. macrodonta Walker, 1906, E. (D. similis Chevreux, 1912, E. (H. georgiana Schellenberg, 1931 and E. (H. inermis Walker, 1903 are re-described and illustrated. Besides the monographic treatment of Epimeriidae from the Southern Ocean, a brief overview and identification keys are given for their putative and potential relatives from the same ocean, i.e., the Antarctic and sub-Antarctic members of the following eusiroid families: Acanthonotozomellidae Coleman & J.L. Barnard, 1991, Dikwidae Coleman & J.L. Barnard, 1991, Stilipedidae Holmes, 1908 and Vicmusiidae Just, 1990. This overview revealed the existence of a new large and characteristic species of Alexandrella Chevreux, 1911, A. chione sp. nov. but also shows that the taxonomy of that genus remains poorly known and that several ‘variable widespread eurybathic species’ probably are species complexes. Furthermore, the genera Bathypanoploea Schellenberg, 1939 and Astyroides Birstein & Vinogradova, 1960 are considered to be junior synonyms of Alexandrella. Alexandrella mixta Nicholls, 1938 and A. pulchra Ren in Ren & Huang, 1991 are re-established herein, as valid species. It is pointed out that this insufficient taxonomic knowledge of Antarctic amphipods impedes ecological and biogeographical studies requiring precise identifications. Stacking photography was used for the first time to provide iconographic support in amphipod taxonomy, and proves to be a rapid and efficient illustration method for large tridimensionally geometric species. A combined morphological and molecular approach was used whenever possible for distinguishing Epimeria species, which were often very similar (albeit never truly cryptic and sometimes exhibited allometric and individual variations. However in several cases, taxa were characterized by morphology only, whenever the specimens available for study were inappropriately fixed or when no sequences could be obtained. A large number of Epimeria species, formerly considered as eurybathic and widely distributed, proved to be complexes of species, with a narrower (overlapping or not distribution. The distributional range of Antarctic Epimeria is very variable from species to species. Current knowledge indicates that some species from the Scotia Arc and the tip of the Antarctic Peninsula are narrow range endemics, sometimes confined to one island, archipelago, or ridge (South Georgia, South Orkney Islands, Elephant Island or Bruce Ridge; other species have a distribution encompassing a broader region, such as the eastern shelf of the Weddell Sea, or extending from the eastern shelf of the Weddell Sea to Adélie Coast. The most widely distributed species are E. (D. colemani subgen. et sp. nov., E. (E. macronyx (Walker, 1906, E. (H. inermis Walker, 1903 and E. (L. walkeri (K.H. Barnard, 1930, which have been recorded from the Antarctic Peninsula/South Shetland Islands area to the western Ross Sea. Since restricted distributions are common among Antarctic and sub-Antarctic Epimeria, additional new species might be expected in areas such as the Kerguelen Plateau, eastern Ross Sea, Amundsen Sea and the Bellingshausen Sea or isolated seamounts and ridges, where there are currently no Epimeria recorded. The limited distribution of many Epimeria species of the Southern Ocean is presumably related to the poor dispersal capacity in most species of the genus. Indeed with the exception of the pelagic and semi-pelagic species of the subgenus Epimeriella, they are heavy strictly benthic organisms without larval stages, and they have no exceptional level of eurybathy for Antarctic amphipods. Therefore, stretches deeper than 1000 m seem to be efficient geographical barriers for many Epimeria species, but other isolating factors (e.g., large stretches poor in epifauna might also be at play. The existence of endemic shelf species with limited dispersal capacities in the Southern Ocean (like many Epimeria suggests the existence of multiple ice-free shelf or upper slope refugia during the Pleistocene glaciations within the distributional and bathymetric range of these species. Genera with narrow range endemics like Epimeria would be excellent model taxa for locating hotspots of Antarctic endemism, and thus potentially play a role in proposing meaningful Marine Protected Areas (MPAs in the Southern Ocean.

  6. Two new species of Urothoe (Crustacea, Amphipoda, Gammaridea From The East Johor Islands Archipelago, Malaysia

    Directory of Open Access Journals (Sweden)

    Azman Abdul Rahim

    2011-03-01

    Full Text Available Two new species of urothoid amphipods from Pulau Sibu and Pulau Tinggi, Johor are described and illustrated. The specimens of Urothoe sibuensis new species were collected by vertical haul plankton net and is distinctively different from other existing Urothoe species by these combination of special characters; similar gnathopods 1–2 with short and stout propodus expanded into poorly defined palms; large eyes and epimeron 3 smooth. Urothoe tinggiensis new species as collected using an airlift suction sampler at seagrass area is characterized by its different gnathopodal configuration with setose dactylus of 5th pereopod; eyes minute; carpus is wider than merus in the 5th pereopod; subquadrate coxa 4; merus and carpus of pereopods 6–7 are linear.

  7. Physiological and behavioural responses of Gammarus pulex (Crustacea: Amphipoda) exposed to cadmium

    International Nuclear Information System (INIS)

    Felten, V.; Charmantier, G.; Mons, R.; Geffard, A.; Rousselle, P.; Coquery, M.; Garric, J.; Geffard, O.

    2008-01-01

    The aim of this study was to investigate the effects of cadmium on physiological and behavioural responses in Gammarus pulex. In a first experiment, cadmium LC50s for different times were evaluated in 264 h experiment under continuous mode of exposure (LC50 96h = 82.1 μg L -1 , LC50 120h = 37.1 μg L -1 , LC50 168h = 21.6 μg L -1 , LC50 264h = 10.5 μg L -1 ). In a second experiment, the physiological and behavioural responses of the amphipod exposed to cadmium (0, 7.5 and 15 μg L -1 ) were investigated under laboratory conditions. The mortality and the whole body cadmium concentration of organisms exposed to cadmium were significantly higher than in controls. Concerning physiological responses, cadmium exposure exerted a significant decrease on osmolality and haemolymph Ca 2+ concentration, but not on haemolymph Na + and Cl - concentrations, whereas the Na + /K + -ATPase activity was significantly increased. Behavioural responses, such as feeding rate, locomotor and ventilatory activities, were significantly reduced in Cd exposed organisms. Mechanism of cadmium action and consequent energetic reallocation in favour of maintenance functions (i.e., osmoregulation) are discussed. The results of this study indicate that osmolality and locomotor activity in G. pulex could be effective ecophysiological/behavioural markers to monitor freshwater ecosystem and to assess the health of organisms

  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. PMID:25354099

  9. Red Sea Leucothoidae (Crustacea: Amphipoda) including new and re-described species

    KAUST Repository

    White, Kristine N.; Krapp-Schickel, Traudl

    2017-01-01

    Examination of leucothoid amphipods of the Red Sea has revealed seven species not previously reported from this location. Leucothoe minoculis sp. nov., Leucothoe pansa sp. nov., Leucothoe reimeri sp. nov., and Paranamixis sommelieri sp. nov. are described and the range of Leucothoe predenticulata Ledoyer, 1978, L. acutilobata Ledoyer, 1978 and L. squalidens Ledoyer, 1978 is expanded to include the Red Sea. Clarification of reports of L. acanthopus Schellenberg, 1928 and L. bannwarthi (Schellenberg, 1928) is provided and Leucothoe alani sp. nov. is described from outside the Red Sea.

  10. Flexible omnivory in Dikerogammarus villosus (Sowinsky, 1894) (Amphipoda) — Amphipod Pilot Species Project (AMPIS) report 5

    NARCIS (Netherlands)

    Platvoet, D.; van der Velde, G.; Dick, J.T.A.; Li, S.

    2009-01-01

    Feeding in Dikerogammarus villosus (Sowinsky, 1894) males was observed in the field and recorded on video in the laboratory. The following feeding modes were recognized: detritus feeding, grazing, particle feeding, coprophagy, predation on benthic and free swimming invertebrates, predation on fish

  11. 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

  12. Distribution of Oxycephalidae (Hyperiidea-Amphipoda) in the Indian Ocean- A statistical study

    Digital Repository Service at National Institute of Oceanography (India)

    Nair, K.K.C.; Jayalakshmy, K.V.

    Statistical analysis of oxycephalids on coexistence of the species showed two clusters of high affinity in the Arabian Sea, four in the Bay of Bengal, one in the South East Indian Ocean and three in the South West Indian Ocean. Species occurring...

  13. The species of the genus Pseudoniphargus Chevreux, 1901 (Amphipoda) from northern Spain

    NARCIS (Netherlands)

    Notenboom, Jos

    1986-01-01

    Based on new material collected in 1983, 1984, and 1985, the genus Pseudoniphargus proves to be distributed in northern Spain from Asturias, in the western part of the Cordillera Cantabrica, to Navarra and Huesca, in the headlands of the Pyrenees; and from coastal Atlantic regions up to the northern

  14. Species of the genus Pseudoniphargus Chevreux, 1901 (Amphipoda) from the Betic Cordillera of southern Spain

    NARCIS (Netherlands)

    Notenboom, Jos

    1987-01-01

    The genus Pseudoniphargus, up to now represented in southern Spain by a single species, branchiatus Stock, appears to be widely distributed in the area. Through the present study, based on new collections obtained in 1984 and 1985, a total of 15 species is recognized. The distribution of

  15. Maeridae from the Indo-Pacific: Elasmopus, Leeuwinella gen. nov., Maeropsis, Pseudelasmopus and Quadrimaera (Amphipoda: Crustacea).

    Science.gov (United States)

    Hughes, Lauren E

    2015-12-22

    Twenty-two species of Maeridae including the new genus, Leeuwinella, and eight new species are described from Indo-Pacific waters. Leeuwinella mistakensis gen. et sp. nov. from southern Western Australia has dorsal carinae and serrate epimeral margins on pleonites 1-3 and mandibular palp article 3 concave; this significant combination of characters justifies erection of a new genus. Elasmopus coxacallus sp. nov., with a castelloserrate posterior margin of pereopod 7 presents a novel character for the genus, which contains over 100 described species. Elasmopus incomptus sp. nov. and E. norfolkensis sp. nov. are also described from Norfolk Island, South Pacific, while new distribution records are provided for E. gracilis Schellenberg, 1938, E. integer Myers, 1989, and E. molokai J.L. Barnard, 1970 from northwestern Australia, and E. souillacensis Appadoo & Myers, 2003, from the Kermadec Islands. New distribution records for Maeropsis griffini (Berents, 1983) from Bedout Island in Western Australia are the first of the species outside the Queensland type locality and new records of M. thetis (Lowry & Springthorpe, 2005) from mainland Australia to Tasmania and across the Tasman Sea extending its range. Pseudelasmopus walkerae sp. nov. is described from Norfolk Island, and is the second species recorded in the genus, previously known only from Mauritius. Lastly, three new Quadrimaera species, Q. gregoryi, Q. brownorum and Q. vallaris, along with eight known Quadrimaera species, are reported from various locations extending their distributions in the Indo-Pacific.

  16. Red Sea Leucothoidae (Crustacea: Amphipoda) including new and re-described species

    KAUST Repository

    White, Kristine N.

    2017-05-31

    Examination of leucothoid amphipods of the Red Sea has revealed seven species not previously reported from this location. Leucothoe minoculis sp. nov., Leucothoe pansa sp. nov., Leucothoe reimeri sp. nov., and Paranamixis sommelieri sp. nov. are described and the range of Leucothoe predenticulata Ledoyer, 1978, L. acutilobata Ledoyer, 1978 and L. squalidens Ledoyer, 1978 is expanded to include the Red Sea. Clarification of reports of L. acanthopus Schellenberg, 1928 and L. bannwarthi (Schellenberg, 1928) is provided and Leucothoe alani sp. nov. is described from outside the Red Sea.

  17. The genus Bathyporeia Lindström, 1855, in western Europe (Crustacea: Amphipoda: Pontoporeiidae)

    NARCIS (Netherlands)

    Udekem d’Acoz, d' C.

    2004-01-01

    The amphipod genus Bathyporeia Lindström, 1855, on the European Atlantic coasts is revised and new identification keys are provided. The importance of new characters such as the morphology of the first uropod is stressed. The following species are fully redescribed and illustrated: B. elegans

  18. Two new species of Urothoe (Crustacea, Amphipoda, Gammaridea) from the East Johor Islands Archipelago, Malaysia.

    Science.gov (United States)

    Azman, B A R; Melvin, C W H

    2011-03-24

    Two new species of urothoid amphipods from Pulau Sibu and Pulau Tinggi, Johor are described and illustrated. The specimens of Urothoe sibuensis new species were collected by vertical haul plankton net and is distinctively different from other existing Urothoe species by these combination of special characters; similar gnathopods 1-2 with short and stout propodus expanded into poorly defined palms; large eyes and epimeron 3 smooth. Urothoe tinggiensis new species as collected using an airlift suction sampler at seagrass area is characterized by its different gnathopodal configuration with setose dactylus of 5th pereopod; eyes minute; carpus is wider than merus in the 5th pereopod; subquadrate coxa 4; merus and carpus of pereopods 6-7 are linear.

  19. Effekte von Xenohormonen auf die limnischen Invertebraten Gammarus fossarum (Crustacea, Amphipoda) und Marisa cornuarietis (Mollusca, Prosobranchia)

    OpenAIRE

    Schirling, Martin

    2005-01-01

    In dieser Arbeit werden Effekte von Xenohormonen auf Gammarus fossarum und Marisa cornuarietis anhand verschiedener Parameter, auf unterschiedlichen biologischen Ebenen dargestellt. In einem Laborexperiment mit G. fossarum, das Grundlage für weitere Untersuchungen im Rahmen dieser Arbeit war, konnte gezeigt werden, dass sich die Stressproteine hsp90 und hsp70 im Laufe der Oocytenreifung gegenläufig verhalten. Sowohl in einem Freilandversuch, bei dem der Einfluss von Kläranlageneinleitern ...

  20. A new species of Cymadusa Savigny, 1816 (Crustacea: Amphipoda: Ampithoidae from northeastern Brazil

    Directory of Open Access Journals (Sweden)

    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.

  1. Reproductive biology and adaptability of the invasive alien freshwater Amphipod Crangonyx floridanus (Crustacea: Amphipoda, Crangonyctidae).

    Science.gov (United States)

    Tojo, Koji; Tanaka, Yoshiki; Kuranishi, Ryoichi B; Kanada, Shoji

    2010-06-01

    We studied the reproductive biology and adaptability of the alien freshwater crangonyctid amphipod Crangonyx floridanus, currently inhabiting a large portion of Japan, both in the field and under controlled laboratory conditions. In the Chikuma River population of this alien amphipod, egg-bearing individuals were found throughout the year. In terms of egg maturation cycle, egg development (during embryogenesis), and egg count per ovipositional cycle, these amphipods display a very efficient reproductive system. This study also established their adaptability to a wide range of water temperatures (primarily 4-20 degrees C, however in some cases, these individuals are able to survive at up to 30 degrees C). C. floridanus's strong capacity to adapt to broad and variable environmental conditions is certainly contributing to its high rate of population increase, and rapid dispersion throughout Japan.

  2. Stygofauna of the Canary Islands, 8 Amphipoda (Crustacea) from inland groundwaters of Fuerteventura

    NARCIS (Netherlands)

    Stock, Jan H.

    1988-01-01

    New material of Bogidiella from Fuenteventura (Canary Islands) provided evidence that the specimens of the genus previously recorded from inland groundwaters belong to a species new to science: B. (Stygogidiella) purpuriae, closely related to the thalassostygobiont, B. (S.) uniramosa from Lanzarote.

  3. Survey of Biofouling an Australian Navy Ships: Crustacea; Isopoda and Amphipoda; Caprellidea

    Science.gov (United States)

    2008-01-01

    amphipod behaviour and predatory strikes by fish . Journal of experimental marine Biology and Ecology 126:173-180, 1989. W. T. Calman. Crustacea. In...Limnoriidea and Sphaeromatidae be used to better reflect their phylogeny . In considering the suitability of maintaining the suborder Flabellifera, it...Caprellidae). Estuarine and Coastal Marine Science 10:225-237, 1979. E. A. Caine. Comparitive functional morphology of feeding in three species of

  4. The functional and physiological status of Gammarus fossarum (Crustacea; Amphipoda) exposed to secondary treated wastewater

    International Nuclear Information System (INIS)

    Bundschuh, Mirco; Zubrod, Jochen P.; Schulz, Ralf

    2011-01-01

    Climate change scenarios predict lower flow rates during summer that may lead to higher proportions of wastewater in small and medium sized streams. Moreover, micropollutants (e.g. pharmaceuticals and other contaminants) continuously enter aquatic environments via treated wastewater. However, there is a paucity of knowledge, whether extended exposure to secondary treated wastewater disrupts important ecosystem functions, e.g. leaf breakdown. Therefore, the amphipod shredder Gammarus fossarum was exposed to natural stream water (n = 34) and secondary treated wastewater (n = 32) for four weeks in a semi-static test system under laboratory conditions. G. fossarum exposed to wastewater showed significant reductions in feeding rate (25%), absolute consumption (35%), food assimilation (50%), dry weight (18%) and lipid content (22%). Thus, high proportions of wastewater in the stream flow may affect both the breakdown rates of leaf material and thus the availability of energy for the aquatic food web as well as the energy budget of G. fossarum. - Micropollutants in wastewater cause functional and physiological alteration in a leaf-shredding amphipod.

  5. Oxycephalus longipes Spandl, 1927 a valid species of the genus Oxycephalus (Amphipoda, Hyperiidea, Oxycephalidae)

    Digital Repository Service at National Institute of Oceanography (India)

    Nair, K.K.C.

    This is the first description on an adult of @iOxycephalus longipes@@ Spandl, 1927. The original record was based on juvenile females. Since its description, the species has not been recorded again, hence its validity remained uncertain. The present...

  6. Ecotoxicological assessment of the pharmaceutical fluoxetine hydrochloride and the surfactant dodecyl sodium sulfate after their submission to ionizing radiation treatment; Avaliacao ecotoxicologica do farmaco cloridrato de fluoxetina e do surfactante dodecil sulfato de sodio quando submetidos a tratamento por radiacao ionizante

    Energy Technology Data Exchange (ETDEWEB)

    Santos, Dymes Rafael Alves dos

    2011-07-01

    The use of pharmaceuticals and personal care products and the consequent and continuous input of this substances in the environment generates an increasing need to investigate the presence, behavior and the effects on aquatic biota, as well as new ways to treat effluents containing such substances. Fluoxetine hydrochloride is an active ingredient used in the treatment of depressive disorders and anxiety. As the surfactant sodium dodecyl sulfate is present in many cleaning and personal care products. The present study aimed on assessing the acute toxicity of fluoxetine hydrochloride, sodium dodecyl sulfate and the mixture of both to the aquatic organisms Hyalella azteca, Daphnia similis and Vibrio ficheri. Reducing the toxicity of fluoxetine and the mixture after treatment with ionizing radiation from industrial electron beam accelerator has also been the focus of this study. For Daphnia similis the average values of CE50-4{sub 8h} found for the non-irradiated drug, surfactant and mixture were 14.4 %, 9.62 % and 13.8 %, respectively. After irradiation of the substances, the dose 5 kGy proved itself to be the most effective dose for the treatment of the drug and the mixture as it was obtained the mean values for CE50{sub 48h} 84.60 % and > 90 %, respectively. For Hyalella azteca the acute toxicity tests were performed for water column with duration of 96 hours, the mean values for CE50{sub 96h} found for the drug, the surfactant and the mixture non-irradiated were 5.63 %, 19.29 %, 6.27 %, respectively. For the drug fluoxetine and the mixture irradiated with 5 kGy, it was obtained 69.57 % and 77.7 %, respectively. For Vibrio ficheri the acute toxicity tests for the untreated drug and the drug irradiated with 5 kGy it was obtained CE50{sub 15min} of 6.9 % and 32.88 % respectively. These results presented a reduction of the acute toxicity of the test-substances after irradiation. (author)

  7. Ecotoxicological assessment of the pharmaceutical fluoxetine hydrochloride and the surfactant dodecyl sodium sulfate after their submission to ionizing radiation treatment

    International Nuclear Information System (INIS)

    Santos, Dymes Rafael Alves dos

    2011-01-01

    The use of pharmaceuticals and personal care products and the consequent and continuous input of this substances in the environment generates an increasing need to investigate the presence, behavior and the effects on aquatic biota, as well as new ways to treat effluents containing such substances. Fluoxetine hydrochloride is an active ingredient used in the treatment of depressive disorders and anxiety. As the surfactant sodium dodecyl sulfate is present in many cleaning and personal care products. The present study aimed on assessing the acute toxicity of fluoxetine hydrochloride, sodium dodecyl sulfate and the mixture of both to the aquatic organisms Hyalella azteca, Daphnia similis and Vibrio ficheri. Reducing the toxicity of fluoxetine and the mixture after treatment with ionizing radiation from industrial electron beam accelerator has also been the focus of this study. For Daphnia similis the average values of CE50-4 8h found for the non-irradiated drug, surfactant and mixture were 14.4 %, 9.62 % and 13.8 %, respectively. After irradiation of the substances, the dose 5 kGy proved itself to be the most effective dose for the treatment of the drug and the mixture as it was obtained the mean values for CE50 48h 84.60 % and > 90 %, respectively. For Hyalella azteca the acute toxicity tests were performed for water column with duration of 96 hours, the mean values for CE50 96h found for the drug, the surfactant and the mixture non-irradiated were 5.63 %, 19.29 %, 6.27 %, respectively. For the drug fluoxetine and the mixture irradiated with 5 kGy, it was obtained 69.57 % and 77.7 %, respectively. For Vibrio ficheri the acute toxicity tests for the untreated drug and the drug irradiated with 5 kGy it was obtained CE50 15min of 6.9 % and 32.88 % respectively. These results presented a reduction of the acute toxicity of the test-substances after irradiation. (author)

  8. Chronic toxicity of nickel-spiked freshwater sediments: variation in toxicity among eight invertebrate taxa and eight sediments

    Science.gov (United States)

    Besser, John M.; Brumbaugh, William G.; Ingersoll, Christopher G.; Ivey, Chris D.; Kunz, James L.; Kemble, Nile E.; Schlekat, Christian E.; Garman, Emily R.

    2013-01-01

    This study evaluated the chronic toxicity of Ni-spiked freshwater sediments to benthic invertebrates. A 2-step spiking procedure (spiking and sediment dilution) and a 2-stage equilibration period (10 wk anaerobic and 1 wk aerobic) were used to spike 8 freshwater sediments with wide ranges of acid-volatile sulfide (AVS; 0.94–38 µmol/g) and total organic carbon (TOC; 0.42–10%). Chronic sediment toxicity tests were conducted with 8 invertebrates (Hyalella azteca, Gammarus pseudolimnaeus, Chironomus riparius, Chironomus dilutus, Hexagenia sp., Lumbriculus variegatus, Tubifex tubifex, and Lampsilis siliquoidea) in 2 spiked sediments. Nickel toxicity thresholds estimated from species-sensitivity distributions were 97 µg/g and 752 µg/g (total recoverable Ni; dry wt basis) for sediments with low and high concentrations of AVS and TOC, respectively. Sensitive species were tested with 6 additional sediments. The 20% effect concentrations (EC20s) for Hyalella and Gammarus, but not Hexagenia, were consistent with US Environmental Protection Agency benchmarks based on Ni in porewater and in simultaneously extracted metals (SEM) normalized to AVS and TOC. For Hexagenia, sediment EC20s increased at less than an equimolar basis with increased AVS, and toxicity occurred in several sediments with Ni concentrations in SEM less than AVS. The authors hypothesize that circulation of oxygenated water by Hexagenia led to oxidation of AVS in burrows, creating microenvironments with high Ni exposure. Despite these unexpected results, a strong relationship between Hexagenia EC20s and AVS could provide a basis for conservative site-specific sediment quality guidelines for Ni.

  9. Integrated assessment of the impacts of agricultural drainwater in the Salinas River (California, USA)

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, B.S.; Hunt, J.W.; Phillips, B.M.; Nicely, P.A.; Vlaming, V. de; Connor, V.; Richard, N.; Tjeerdema, R.S

    2003-08-01

    Invertebrate mortality was correlated with levels of water and sediment contaminatioin in the Salinas River. - The Salinas River is the largest of the three rivers that drain into the Monterey Bay National Marine Sanctuary in central California. Large areas of this watershed are cultivated year-round in row crops and previous laboratory studies have demonstrated that acute toxicity of agricultural drainwater to Ceriodaphnia dubia is caused by the organophosphate (OP) pesticides chlorpyrifos and diazinon. In the current study, we used a combination of ecotoxicologic tools to investigate incidence of chemical contamination and toxicity in waters and sediments in the river downstream of a previously uncharacterized agricultural drainage creek system. Water column toxicity was investigated using a cladoceran C. dubia while sediment toxicity was investigated using an amphipod Hyalella azteca. Ecological impacts of drainwater were investigated using bioassessments of macroinvertebrate community structure. The results indicated that Salinas River water downstream of the agricultural drain is acutely toxic to Ceriodaphnia, and toxicity to this species was highly correlated with combined toxic units (TUs) of chlorpyrifos and diazinon. Laboratory tests were used to demonstrate that sediments in this system were acutely toxic to H. azteca, which is a resident genus. Macroinvertebrate community structure was moderately impacted downstream of the agricultural drain input. While the lowest macroinvertebrate abundances were measured at the station demonstrating the greatest water column and sediment toxicity and the highest concentrations of pesticides, macroinvertebrate metrics were more significantly correlated with bank vegetation cover than any other variable. Results of this study suggest that pesticide pollution is the likely cause of laboratory-measured toxicity in the Salinas River samples and that this factor may interact with other factors to impact the

  10. Integrated assessment of the impacts of agricultural drainwater in the Salinas River (California, USA)

    International Nuclear Information System (INIS)

    Anderson, B.S.; Hunt, J.W.; Phillips, B.M.; Nicely, P.A.; Vlaming, V. de; Connor, V.; Richard, N.; Tjeerdema, R.S.

    2003-01-01

    Invertebrate mortality was correlated with levels of water and sediment contaminatioin in the Salinas River. - The Salinas River is the largest of the three rivers that drain into the Monterey Bay National Marine Sanctuary in central California. Large areas of this watershed are cultivated year-round in row crops and previous laboratory studies have demonstrated that acute toxicity of agricultural drainwater to Ceriodaphnia dubia is caused by the organophosphate (OP) pesticides chlorpyrifos and diazinon. In the current study, we used a combination of ecotoxicologic tools to investigate incidence of chemical contamination and toxicity in waters and sediments in the river downstream of a previously uncharacterized agricultural drainage creek system. Water column toxicity was investigated using a cladoceran C. dubia while sediment toxicity was investigated using an amphipod Hyalella azteca. Ecological impacts of drainwater were investigated using bioassessments of macroinvertebrate community structure. The results indicated that Salinas River water downstream of the agricultural drain is acutely toxic to Ceriodaphnia, and toxicity to this species was highly correlated with combined toxic units (TUs) of chlorpyrifos and diazinon. Laboratory tests were used to demonstrate that sediments in this system were acutely toxic to H. azteca, which is a resident genus. Macroinvertebrate community structure was moderately impacted downstream of the agricultural drain input. While the lowest macroinvertebrate abundances were measured at the station demonstrating the greatest water column and sediment toxicity and the highest concentrations of pesticides, macroinvertebrate metrics were more significantly correlated with bank vegetation cover than any other variable. Results of this study suggest that pesticide pollution is the likely cause of laboratory-measured toxicity in the Salinas River samples and that this factor may interact with other factors to impact the

  11. The distribution of littoral caprellids (Crustacea: Amphipoda: Caprellidea along the Pacific coast of continental Chile La distribución de caprélidos litorales (Crustacea: Amphipoda: Caprellidea en la costa del Pacífico de Chile continental

    Directory of Open Access Journals (Sweden)

    MARTIN THIEL

    2003-06-01

    Full Text Available Many littoral caprellid species have a very ample distribution, some having been reported from all over the world. The cosmopolitan distribution of many littoral caprellid species might be facilitated by the fact that they are often associated with fouling communities on floating objects, which have a high potential of far-range dispersal. This dispersal potential may also have implications for the distribution of caprellids on local and regional scales. Herein we examined the distribution of littoral caprellid species on two spatial scales, local (tens of kilometers and regional (hundreds of kilometers along the Pacific coast of continental Chile. On the local scale, we studied the caprellid fauna in different habitats (intertidal boulders, subtidal algal and seagrass beds, fouling community on buoys and ropes; on the regional scale we focused only on caprellids associated with the fouling community on buoys and ropes. We found a total of six caprellid species, some of which were very abundant both on the local as well as on the regional scale. On the local scale we found a difference between the three studied habitat types with respect to the assemblage of caprellid species, some of which were found in more than one habitat. The highest species richness and abundance of caprellids was found in the fouling community associated with anchored buoys and ropes. On the regional scale we found very high numbers of caprellids in the fouling community of the northern region (n of 30°S, and decreasing abundances and species richness in the central region (30-37° S. No caprellids were found in the southern region of the study area (37-42° S. This pattern coincides with the global distribution of littoral caprellid species, which are most abundant and diverse at low latitudes but occur in low abundances and low diversity at high latitudes. Detached buoys that were found a few km off the coast harbored similar caprellid assemblages (including ovigerous females as anchored buoys, suggesting that buoys and other floating substrata (litter, macroalgae may facilitate dispersal of caprellids (and other epibiota along the Pacific coast of Chile. Since artificial and natural floating substrata are also abundant at high latitudes it is inferred that the low diversity of littoral caprellids at high latitudes is not due to lack of dispersal vectors, but rather of other factorsMuchas especies de caprélidos del litoral presentan una amplia distribución, algunas han sido citadas a lo largo de todo el mundo. La distribución cosmopolita de muchas especies de caprélidos podría deberse al hecho de que se asocian frecuentemente a las comunidades "fouling" en objetos flotantes, que presentan una capacidad importante de dispersión a largas distancias. Esta capacidad de dispersión puede tener implicaciones en la distribución de caprélidos a escala local y regional. En este estudio, nosotros examinamos la distribución de las especies de caprélidos litorales en dos escalas espaciales, local (decenas de kilómetros y regional (cientos de kilómetros, a lo largo de la costa Pacífico de Chile continental. A escala local se estudió la fauna de caprélidos en distintos hábitats (bolones intermareales, praderas de algas y fanerógamas marinas, comunidades "fouling" de boyas y cuerdas; a escala regional el estudio se centró solamente en los caprélidos asociados a boyas y cuerdas. Se encontraron un total de seis especies de caprélidos, algunos de los cuales fueron muy abundantes a escala local y regional. A escala local, existió una diferencia entre los tres tipos de hábitat con respecto a la fauna de caprélidos, algunos de los cuales estuvieron presentes en más de un hábitat. Los valores más altos de riqueza específica y abundancia se encontraron en la comunidad "fouling" asociada a boyas y cuerdas ancladas. A escala regional, los caprélidos fueron más abundantes y diversos en las comunidades "fouling" de la región norte (n de 30° S, mientras que la abundancia y riqueza de especies disminuyeron en la región central (30-37° S. No se encontraron caprélidos en la región sur del área de estudio (37-42° S. Este patrón coincide con la distribución global de especies de caprélidos litorales, mostrando los valores más altos de abundancia y riqueza de especies en las bajas latitudes y los valores más bajos en las altas latitudes. Boyas desprendidas desde sus amarras y encontradas a varios km de la costa albergaron asociaciones de caprélidos (incluyendo hembras ovígeras similares a las de las boyas fijadas, sugiriendo que las boyas y otros sustratos flotantes pueden facilitar la dispersión de caprélidos (y otra epifauna a lo largo de la costa Pacífico de Chile. Teniendo en cuenta que los sustratos flotantes naturales y artificiales son también abundantes en altas latitudes se infiere que la baja diversidad de caprélidos litorales en altas latitudes no se debe a la falta de vectores dispersantes sino a otros factores

  12. Hipéridos (Crustacea: Amphipoda en el sector norte del Pacífico oriental tropical colombiano Hyperiids (Crustacea: Amphipoda along the northern margin of the eastern tropical Pacific of Colombia

    Directory of Open Access Journals (Sweden)

    Bellineth Valencia

    2009-01-01

    Full Text Available Con el objetivo de analizar la composición, abundancia y diversidad de la comunidad de anfipodos hipéridos en las localidades de Punta Cruces y Cabo Marzo, costa norte del Pacífico colombiano (Pacífico oriental tropical, se realizó una campaña de muestreo en enero de 2008 siguiendo una malla de nueve estaciones. Se encontró un total de 20 especies, siendo Lestrigonus bengalensis e Hyperioides sibaginis las más abundantes, representando el 91% de la comunidad en Cabo Marzo y el 95% de la comunidad en Punta Cruces. La abundancia y la diversidad en las dos localidades fueron muy variables, y no presentaron diferencias significativas (Mann Whitney; p > 0,05. Así mismo, se estableció que la similitud en términos de la composición y la abundancia entre las comunidades de hipéridos de Punta Cruces y Cabo Marzo fue de un 64,6%. Este trabajo proporciona información inédita sobre un componente poco estudiado del zooplancton en el Pacífico oriental tropical, incrementando el número de especies registradas para el Pacífico colombiano.In order to analyze the composition, abundance, and diversity of hyperiid amphipods at Punta Cruces and Cabo Marzo, on the northern Pacific coast of Colombia (eastern tropical Pacific, a sampling campaign was carried out in January 2008 that covered a nine-station sampling grid. Twenty species were found, of which Lestrigonus bengalensis and Hyperioides sibaginis were the most abundant (91% of the community at Cabo Marzo and 95% at Punta Cruces. Although the abundance and diversity were highly variable at both sites, they did not differ significantly (Mann Whitney; p > 0.05. Likewise, the similarity in terms of composition and abundance between the hyperiid communities at Punta Cruces and Cabo Marzo was 64.6%. This re-search provides new information regarding a scarcely studied component of the zooplankton in the eastern tropical Pacific and increases the number of hyperiid species reported for the Pacific Ocean of Colombia.

  13. On the trophic ecology of Gammaridea (Crustacea: Amphipoda) in coastal waters: A European-scale analysis of stable isotopes data

    Science.gov (United States)

    Mancinelli, Giorgio

    2012-12-01

    Gammaridean amphipods are found throughout a diverse range of coastal and brackish environments and are generally considered macrophagous herbivores/detritivores. While predation and cannibalism have been shown to be common in freshwater species, motivating a revision of the group functional role, only qualitative information is available on marine Gammaridea. In this study, a survey was conducted of the available literature on stable C and N isotopic signatures of macrophagous, fully aquatic Gammaridea and their potential basal resources in European brackish and coastal environments. The contribution of intra- and inter-specific predation to the signatures of gammarideans was verified by a mixing model procedure where the diet-tissue enrichment constant was not set a priori. Specifically, for each study included in the survey the minimum and maximum diet-tissue nitrogen enrichment factors (Δ15Nmin and Δ15Nmax) providing a non-zero solution were calculated for a range of carbon enrichment factors, assuming that both metrics would increasingly differ from the values expected for a single trophic level as predation and/or cannibalism increased in the diet of the consumer. The minimum enrichment factors Δ15Nmin estimated for a Δ13C of -2.6‰ and +0.5‰ were found to be independent from resource-related artefacts and provided the highest number of successful model runs. Δ15Nmin values were consistent with a diet based on living or decaying primary producers and not compatible with cannibalism or intra-guild predation. However, they showed a bimodal distribution and were on average far below the range found in the literature, matching the enrichment factors of gammarideans measured under laboratory conditions. These results are discussed considering the interaction of the distinctive isotopic features of basal resources in coastal habitats and the biology and ecology of gammaridean amphipods. Particular emphasis is placed on the high variability of nitrogen enrichment factors, and on their crucial role in attaining reliable results from isotopic models used for food web studies.

  14. Genetic connectivity between land and sea: the case of the beachflea Orchestia montagui (Crustacea, Amphipoda, Talitridae) in the Mediterranean Sea.

    Science.gov (United States)

    Pavesi, Laura; Tiedemann, Ralph; De Matthaeis, Elvira; Ketmaier, Valerio

    2013-04-25

    We examined patterns of genetic divergence in 26 Mediterranean populations of the semi-terrestrial beachflea Orchestia montagui using mitochondrial (cytochrome oxidase subunit I), microsatellite (eight loci) and allozymic data. The species typically forms large populations within heaps of dead seagrass leaves stranded on beaches at the waterfront. We adopted a hierarchical geographic sampling to unravel population structure in a species living at the sea-land transition and, hence, likely subjected to dramatically contrasting forces. Mitochondrial DNA showed historical phylogeographic breaks among Adriatic, Ionian and the remaining basins (Tyrrhenian, Western and Eastern Mediterranean Sea) likely caused by the geological and climatic changes of the Pleistocene. Microsatellites (and to a lesser extent allozymes) detected a further subdivision between and within the Western Mediterranean and the Tyrrhenian Sea due to present-day processes. A pattern of isolation by distance was not detected in any of the analyzed data set. We conclude that the population structure of O. montagui is the result of the interplay of two contrasting forces that act on the species population genetic structure. On one hand, the species semi-terrestrial life style would tend to determine the onset of local differences. On the other hand, these differences are partially counter-balanced by passive movements of migrants via rafting on heaps of dead seagrass leaves across sites by sea surface currents. Approximate Bayesian Computations support dispersal at sea as prevalent over terrestrial regionalism.

  15. Morphological and ontogenetic stratification of abyssal and hadal Eurythenes gryllus sensu lato (Amphipoda: Lysianassoidea) from the Peru-Chile Trench

    Science.gov (United States)

    Eustace, Ryan M.; Ritchie, Heather; Kilgallen, Niamh M.; Piertney, Stuart B.; Jamieson, Alan J.

    2016-03-01

    The globally ubiquitous lysianassoid amphipod, Eurythenes gryllus, has been shown to consist of multiple genetically distinct cryptic taxa, with depth considered a major driver of speciation and morphological divergence. Here we examine morphological variation of E. gryllus sensu lato through a continuous depth distribution that spans from abyssal (3000-6000 m) into hadal depths (>6000 m) in the Peru-Chile Trench (SE Pacific Ocean). Three distinct morphospecies were identified: one was confirmed as being E. magellanicus (4602-5329 m) based on DNA sequence and morphological similarity. The other two morphologically distinct species were named based upon depth of occurrence; Abyssal (4602-6173 m) and Hadal (6173-8074 m). The three Eurythenes morphospecies showed vertical ontogenetic stratification across their bathymetric range, where juveniles were found shallower in their depth range and mature females deeper. Potential ecological and evolutionary drivers that explain the observed patterns of intra and inter-specific structure, such as hydrostatic pressure and topographical isolation, are discussed.

  16. A molecular gut content study of Themisto abyssorum (Amphipoda) from Arctic hydrothermal vent and cold seep systems.

    Science.gov (United States)

    Olsen, Bernt Rydland; Troedsson, Christofer; Hadziavdic, Kenan; Pedersen, Rolf B; Rapp, Hans Tore

    2014-08-01

    The use of DNA as a marker for prey inside the gut of predators has been instrumental in further understanding of known and unknown interactions. Molecular approaches are in particular useful in unavailable environments like the deep sea. Trophic interactions in the deep sea are difficult to observe in situ, correct deep-sea experimental laboratory conditions are difficult to obtain, animals rarely survive the sampling, or the study organisms feed during the sampling due to long hauls. Preliminary studies of vent and seep systems in the Nordic Seas have identified the temperate-cold-water pelagic amphipod Themisto abyssorum as a potentially important predator in these chemosynthetic habitats. However, the prey of this deep-sea predator is poorly known, and we applied denaturing high performance liquid chromatography (DHPLC) to investigate the predator-prey interactions of T. abyssorum in deep-water vent and seep systems. Two deep-water hydrothermally active localities (The Jan Mayen and Loki's Castle vent fields) and one cold seep locality (The Håkon Mosby mud volcano) in the Nordic Seas were sampled, genomic DNA of the stomachs of T. abyssorum was extracted, and 18S rDNA gene was amplified and used to map the stomach content. We found a wide range of organisms including micro-eukaryotes, metazoans and detritus. Themisto abyssorum specimens from Loki's Castle had the highest diversity of prey. The wide range of prey items found suggests that T. abyssorum might be involved in more than one trophic level and should be regarded as an omnivore and not a strict carnivore as have previously been suggested. © 2013 John Wiley & Sons Ltd.

  17. Cryptorchestia ruffoi sp. n. from the island of Rhodes (Greece, revealed by morphological and phylogenetic analysis (Crustacea, Amphipoda, Talitridae

    Directory of Open Access Journals (Sweden)

    Domenico Davolos

    2017-02-01

    Full Text Available A new Cryptorchestia species, Cryptorchestia ruffoi Latella & Vonk, sp. n. from the island of Rhodes in south-eastern Greece, can be distinguished on the basis of morphological and phylogenetic data. Morphological analysis and DNA sequencing of mitochondrial and nuclear protein-coding genes indicated that this species is related to C. cavimana (Cyprus and C. garbinii (Mediterranean regions, with a recent northward expansion. Results supported a genetic separation between the Cryptorchestia species of the east Mediterranean regions and those of the northeast Atlantic volcanic islands examined in this study (C. canariensis, C. gomeri, C. guancha, and C. stocki from the Canary islands, C. monticola from Madeira, and C. chevreuxi from the Azores. The Mediterranean and Atlantic Cryptorchestia species appear to be also morphologically distinct. Cryptorchestia ruffoi sp. n., C. cavimana, C. garbinii, and C. kosswigi (Turkish coast clearly have a small lobe on the male gnathopod 1 merus. This character was the main diagnostic difference between Cryptorchestia (sensu Lowry, 2013 and Orchestia. However, among the six northeast Atlantic island Cryptorchestia species only C. stocki has a small lobe on the merus of gnathopod 1. Reduction or loss of the lobe in the Atlantic Island species cannot be ruled out; however, molecular phylogenetic analysis leads us to presume that this lobe independently evolved between the east Mediterranean Cryptorchestia species and C. stocki from Gran Canaria.

  18. Genetic differentiation in Gammarus fossarum and G. caparti (Crustacea, Amphipoda) with reference to G. pulex pulex in northwestern Europe

    NARCIS (Netherlands)

    Scheepmaker, Maarten; Dalfsen, van Jan

    1989-01-01

    Genetic differentiation among G. fossarum Koch, 1835 from different stations in Germany, Switzerland, Belgium and northern France, and the closely related Belgian form G. caparti Pètre-Stroobants, 1980 was investigated by electrophoresis at 20 enzyme loci. Although morphologically variable,

  19. Under the volcano: phylogeography and evolution of the cave-dwelling Palmorchestia hypogaea (Amphipoda, Crustacea at La Palma (Canary Islands

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    Oromí Pedro

    2008-01-01

    Full Text Available Abstract Background The amphipod crustacean Palmorchestia hypogaea occurs only in La Palma (Canary Islands and is one of the few terrestrial amphipods in the world that have adapted to a strictly troglobitic life in volcanic cave habitats. A surface-dwelling closely related species (Palmorchestia epigaea lives in the humid laurel forest on the same island. Previous studies have suggested that an ancestral littoral Orchestia species colonized the humid forests of La Palma and that subsequent drought episodes in the Canaries reduced the distribution of P. epigaea favouring the colonization of lava tubes through an adaptive shift. This was followed by dispersal via the hypogean crevicular system. Results P. hypogaea and P. epigaea did not form reciprocally monophyletic mitochondrial DNA clades. They showed geographically highly structured and genetically divergent populations with current gene flow limited to geographically close surface locations. Coalescence times using Bayesian estimations assuming a non-correlated relaxed clock with a normal prior distribution of the age of La Palma, together with the lack of association of habitat type with ancestral and recent haplotypes, suggest that their adaptation to cave life is relatively ancient. Conclusion The data gathered here provide evidence for multiple invasions of the volcanic cave systems that have acted as refuges. A re-evaluation of the taxonomic status of the extant species of Palmorchestia is needed, as the division of the two species by habitat and ecology is unnatural. The information obtained here, and that from previous studies on hypogean fauna, shows the importance of factors such as the uncoupling of morphological and genetic evolution, the role of climatic change and regressive evolution as key processes in leading to subterranean biodiversity.

  20. A new species of Nuuanu (Amphipoda: Gammaridea: Melitidae from shallow sandy bottoms of the Balearic Islands (W Mediterranean

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    Damià Jaume

    2006-12-01

    Full Text Available Nuuanu beatricis n. sp., a new melitid amphipod, is described from shallow-water sandy bottoms on the S and SE coasts of Mallorca (Balearic Islands, Mediterranean. It differs from the rest of its congeners in the combination of: (1 non-geniculate antennule, much longer than antenna; (2 distal segment of mandibular palp shorter than second, armed with both D and E setae; (3 second segment of mandibular palp with 2 setae; (4 posteroventral lobe (sensu Lowry and Watson, 2002 absent from posterior margin of coxa 4; (5 reduced spine present on medial surface of coxa 5; (6 posterior margin of basis of pereopod 5 convex; (7 anterodistal lobe of coxa 7 wanting; (8 posterior margin of basis of pereopod 7 sparsely serrated along proximal half only; (9 pleonites 1-2 lacking dorsodistal spines; (10 anterodistal corner of epimeral plate 1 rounded; (11 exopod of uropod 3 longer than protopod; and (12 telson with terminal spine on each lobe. Although the new amphipod could be an alien species introduced from a distant tropical location with alien Caulerpa algae species, it is here regarded as an ancient Mediterranean element owing to its peracarid condition (i.e. reduced potential for dispersal, regressed visual apparatus, and crevicular-interstitial existence. The presumed presence of sternal gills in Nuuanu is rejected after demonstration of the coxal origin of the spiniform structures interpreted elsewhere as sternal gills.

  1. Additive effect of calcium depletion and low resource quality on Gammarus fossarum (Crustacea, Amphipoda) life history traits.

    Science.gov (United States)

    Rollin, Marc; Coulaud, Romain; Danger, Michael; Sohm, Bénédicte; Flayac, Justine; Bec, Alexandre; Chaumot, Arnaud; Geffard, Olivier; Felten, Vincent

    2018-04-01

    Gammarus fossarum is an often-abundant crustacean detritivore that contributes importantly to leaf litter breakdown in oligotrophic, mainly heterotrophic, headwater streams. This species requires large amounts of Ca to moult, thus allowing growth and reproduction. Because resource quality is tightly coupled to the organism's growth and physiological status, we hypothesised that low Ca concentration [Ca] and low food resource quality (low phosphorus [P] and/or reduced highly unsaturated fatty acid [HUFA] contents) would interactively impair molecular responses (gene expression) and reproduction of G. fossarum. To investigate the effects of food resources quality, we experimentally manipulated the P content of sycamore leaves and also used diatoms because they contain high amounts of HUFAs. Three resource quality treatments were tested: low quality (LQ, unmanipulated leaves: low P content), high quality 1 (HQ1; P-manipulated leaves: high P content), and high quality 2 (unmanipulated leaves supplemented with a pellet containing diatoms: high P and HUFA content). Naturally, demineralised stream water was supplemented with CaSO 4 to obtain three Ca concentrations (2, 3.5, and 10.5 mg Ca L -1 ). For 21 days, pairs of G. fossarum were individually exposed to one of the nine treatments (3 [Ca] × 3 resource qualities). At the individual level, strong and significant delays in moult stage were observed in gammarids exposed to lower [Ca] and to lower resource quality, with additive effects lengthening the duration of the reproductive cycle. Effects at the molecular level were investigated by measuring expression of 12 genes involved in energy production, translation, or Ca or P homeostasis. Expression of ATP synthase beta (higher in HQ2), calcified cuticle protein (higher in HQ1 and HQ2), and tropomyosin (higher in HQ2 compared to HQ1) was significantly affected by resource quality, and significant additive effects on Ca transporting ATPase expression were induced by [Ca] and resource quality (higher for low [Ca] and higher resource quality). These results highlight the potential drastic deleterious effects of water [Ca] depletion on G. fossarum physiology, populations, and ecosystem functioning, especially in oligotrophic environments.

  2. Mayaweckelia troglomorpha, a new subterranean amphipod species from Yucatán state, México (Amphipoda, Hadziidae).

    Science.gov (United States)

    Angyal, Dorottya; Solís, Efraín Chávez; Magaña, Benjamín; Balázs, Gergely; Simoes, Nuno

    2018-01-01

    A detailed description of a new stygobiont species of the amphipod family Hadziidae, Mayaweckelia troglomorpha Angyal, sp. n. is given, based on material collected in four cenotes of Yucatán federal state, México. Morphology was studied under light microscopy and with scanning electron microscopy. Morphological description is complemented with mitochondrial cytochrome c oxidase subunit I (COI) sequences as barcodes, with affinities to the related taxa and with notes on the species' ecology. Using COI Bayesian inference and genetic distance analyses, we show that the closest relative of the new species is M. cenoticola , forming a monophyletic group referring to the genus Mayaweckelia . Based on the available sequences, we also revealed that Mayaweckelia and Tuluweckelia are sister genera, standing close to the third Yucatán subterranean genus, Bahadzia . The data gathered on the habitat, distribution, abundance, and ecology will contribute to the conservation planning for M. troglomorpha Angyal, sp. n.

  3. Mantacaprella macaronensis, a new genus and species of Caprellidae (Crustacea: Amphipoda) from Canary Islands and Cape Verde.

    Science.gov (United States)

    Maite, Vázquez-Luis; José M, Guerra-García; Susana, Carvalho; Lydia Png-Gonzalez

    2013-01-01

    Mantacaprella macaronensis new genus, new species, is described based on specimens collected from Canary Islands and Cape Verde. Mantacaprella is close to the genera Parambus, Pseudolirius, Propodalirius and Paracaprella, but can be distinguished by the combination of the following characteristics: pereopods 3, 4 and 5 two-articulate; pereopods 6 and 7 six-articulate; mandibular molar present and palp absent; male abdomen with a pair of well-developed appendages. The new species has been found living in Cymodocea nodosa meadows and Caulerpa prolifera beds from 8.8 to 14.6 m depth in Gran Canaria (Canary Islands), and in natural rocky and artificial habitats (shipwrecks) at 25 m in Sal Island (Cape Verde). Even though the new species is one of the dominant amphipods inhabiting meadows of Cymodocea nodosa in Gran Canaria and in Cape Verde, it had not been described so far. This reflects the lack of knowledge on Macaronesian invertebrates, such as amphipods, and the need of further taxonomical studies to better characterise the whole biodiversity of this region and to design adequate programmes of management and conservation.

  4. A new species of the genus Pontogeneia (Crustacea, Amphipoda) from Matsukawa-ura Inlet, Fukushima Prefecture, Japan

    NARCIS (Netherlands)

    Hirayama, Akira

    1990-01-01

    A new species of the genus Pontogeneia taken from a shallow inlet of Fukushima Prefecture, Japan, is described and figured. The new species is closely related to P. intermedia from Japan Sea and California but is distinguished from it by a slightly dilated propod of gnathopod 1, the presence of

  5. Behaviour of Talitrus saltator (Crustacea: Amphipoda) on a rehabilitated sandy beach on the European Atlantic Coast (Portugal)

    Science.gov (United States)

    Bessa, Filipa; Rossano, Claudia; Nourisson, Delphine; Gambineri, Simone; Marques, João Carlos; Scapini, Felicita

    2013-01-01

    Environmental and human controls are widely accepted as the main structuring forces of the macrofauna communities on sandy beaches. A population of the talitrid amphipod Talitrus saltator (Montagu, 1808) was investigated on an exposed sandy beach on the Atlantic coast of Portugal (Leirosa beach) to estimate orientation capabilities and endogenous rhythms in conditions of recent changes in the landscape (artificial reconstruction of the foredune) and beach morphodynamics (stabilization against erosion from the sea). We tested sun orientation of talitrids on the beach and recorded their locomotor activity rhythms under constant conditions in the laboratory. The orientation data were analysed with circular statistics and multiple regression models adapted to angular distributions, to highlight the main factors and variables influencing the variation of orientation. The talitrids used the sun compass, visual cues (landscape and sun visibility) to orient and the precision of orientation varied according to the tidal regime (rising or ebbing tides). A well-defined free-running rhythm (circadian with in addition a bimodal rhythmicity, likely tidal) was highlighted in this population. This showed a stable behavioural adaptation on a beach that has experienced a process of artificial stabilization of the dune through nourishment actions over a decade. Monitoring the conditions of such dynamic environments and the resilience capacity of the inhabiting macroinfauna is a main challenge for sandy beach ecologists.

  6. Relationship between heavy metals pollution and genetic diversity in Mediterranean populations of the sandhopper Talitrus saltator (Montagu) (Crustacea, Amphipoda)

    International Nuclear Information System (INIS)

    Ungherese, G.; Mengoni, A.; Somigli, S.; Baroni, D.; Focardi, S.; Ugolini, A.

    2010-01-01

    Trace metals are one of the groups of pollutants that reduce genetic variability in natural populations, causing the phenomenon known as 'genetic erosion'. In this study we evaluate the relationship between trace metals contamination (Hg, Cd and Cu) and genetic variability, assessed using fluorescent Inter-Simple Sequence Repeats (fISSRs). We used eight populations of a well-established biomonitor of trace metals on sandy beaches: the amphipod Talitrus saltator. The trace metals analysis confirmed the ability of sandhoppers to accumulate Hg, Cd and Cu. Moreover, populations from sites with high Hg availability had the lowest values of genetic diversity. Our results validate the use of fISSR markers in genetic studies in sandhoppers and support the 'genetic erosion' hypothesis by showing the negative influence of Hg contamination on sandhopper genetic diversity. Therefore, genetic variability assessed with fISSR markers could be successfully employed as a biomarker of Hg exposure. - Genetic variability of sandhoppers is affected by heavy metals contamination.

  7. Four new Gammarus species from Tibetan Plateau with a key to Tibetan freshwater gammarids (Crustacea, Amphipoda, Gammaridae

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    Zhonge Hou

    2018-03-01

    Full Text Available Four new species of the genus Gammarus are described and illustrated from Tibetan Plateau. Gammarus altus sp. n. and G. limosus sp. n. are characterized by pereopods III–IV with a few short setae and uropod III with marginal spines accompanied by short setae. Gammarus kangdingensis sp. n. and G. gonggaensis sp. n. are characterized by pereopods III–IV with long straight setae on posterior margins and inner ramus of uropod III 0.4 times as long as outer ramus. Detailed morphological comparisons with related species are discussed. A key to 15 Gammarus species from the Tibetan Plateau and a map of their distributions are provided.

  8. A new Echinogammarus of the berilloni – group E. Aquilifer nov.sp., from the Pyrenees (Crustacea, Amphipoda)

    NARCIS (Netherlands)

    Pinkster, S.

    1969-01-01

    During a short trip in the western part of the Pyrenees in August 1968 many samples of Gammaridae were collected both on the French and Spanish slopes of this mountain chain. Most of the specimens collected appeared to belong to the species Echinogammarus berilloni (Catta, 1878), or to closely

  9. First record of the invasive and cryptogenic species Jassa slatteryiConlan, 1990 (Crustacea: Amphipoda) in Italian coastal waters

    Science.gov (United States)

    Bonifazi, Andrea; Mancini, Emanuele; Ventura, Daniele

    2018-06-01

    Jassa slatteryi is a cosmopolitan amphipod reported as cryptogenic or invasive species throughout the world. Although it had been signaled in the Mediterranean Sea, it was never found on the Italian coasts. This study represents the first record of J. slatteryi in Italy. A total of 87 specimens were collected on artificial hard substrates in the Port of Civitavecchia (Rome). The presence of this species in the Mediterranean Sea was probably underestimated due to the similar morphological features and ecological requirements of different species of Jassa spp.

  10. Exploring trophic strategies of exotic caprellids (Crustacea: Amphipoda): Comparison between habitat types and native vs introduced distribution ranges

    Science.gov (United States)

    Ros, Macarena; Tierno de Figueroa, José Manuel; Guerra-García, José Manuel; Navarro-Barranco, Carlos; Lacerda, Mariana Baptista; Vázquez-Luis, Maite; Masunari, Setuko

    2014-02-01

    The trophic ecology of non-native species is a key aspect to understand their invasion success and the community effects. Despite the important role of caprellid amphipods as trophic intermediates between primary producers and higher levels of marine food webs, there is very little information on their feeding habits. This is the first comprehensive study on the trophic strategies of two co-occurring introduced caprellids in the Spanish coasts: Caprella scaura and Paracaprella pusilla. The diet of 446 specimens of C. scaura and 230 of P. pusilla was analyzed to investigate whether there were differences in the feeding habits in relation to habitat characteristics (natural vs artificial hard substrata), type of host substrata (bryozoans and hydroids) and native vs introduced distribution ranges (Brazil vs Spain). Results revealed differences in diet preferences of the two species that have important implications for their trophic behaviour and showed a limited food overlap, which may favour their coexistence in introduced areas. In general terms, P. pusilla is a predator species, showing preference by crustacean prey in all of its life stages, while C. scaura feeds mainly on detritus. Although no sex-related diet shifts were observed in either of the species, evidence of ontogenetic variation in diet of C. scaura was found, with juveniles feeding on more amount of prey than adults. No diet differences were found between native and introduced populations within the same habitat type. However, P. pusilla exhibited a shift in its diet when different habitats were compared in the same distribution area, and C. scaura showed a flexible feeding behaviour between different host substrata in the same habitat type. This study shows that habitat characteristics at different scales can have greater influence on the feeding ecology of exotic species than different distribution ranges, and support the hypothesis that a switch between feeding strategies depending on habitat characteristics could favour invasion success.

  11. Safety of the molluscicide Zequanox (R) to nontarget macroinvertebrates Gammarus lacustris (Amphipoda: Gammaridae) and Hexagenia spp. (Ephemeroptera: Ephemeridae)

    Science.gov (United States)

    Waller, Diane L.; Luoma, James A.; Erickson, Richard A.

    2016-01-01

    Zequanox® is a commercial formulation of the killed bacterium, Pseudomonas fluorescens (strain CL145A), that was developed to control dreissenid mussels. In 2014, Zequanox became the second product registered by the United States Environmental Protection Agency (USEPA) for use in open water environments as a molluscicide. Previous nontarget studies demonstrated the safety and selectivity of P. fluorescens CL154A, but the database on the toxicity of the formulation (Zequanox) is limited for macroinvertebrate taxa and exposure conditions. We evaluated the safety of Zequanox to the amphipod Gammarus lacustris lacustris, and nymphs of the burrowing mayfly, Hexagenia spp. at the maximum approved concentration (100 mg/L active ingredient, A.I.) and exposure duration (8 h). Survival of animals was assessed after 8 h of exposure and again at 24 and 96 h post-exposure. Histopathology of the digestive tract of control and treated animals was compared at 96 h post-exposure. The results showed no significant effect of Zequanox on survival of either species. Survival of G. lacustris exceeded 85% in all concentrations at all three sampling time points. Survival of Hexagenia spp. ranged from 71% (control) to 91% at 8 h, 89–93% at 24 h post-exposure, and 70–73% at 96 h post-exposure across all treatments. We saw no evidence of pathology in the visceral organs of treated animals. Our results indicate that application of Zequanox at the maximum approved concentration and exposure duration did not cause significant mortality or treatment-related histopathological changes to G. lacustris and Hexagenia spp.

  12. Temporal variation of the gammaridean fauna (Crustacea, Amphipoda associated with the sponge Mycale angulosa (Porifera, Demospongiae in southeastern Brazil

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    Mariana Fernandes de Britto Costa

    Full Text Available ABSTRACTMarine sponges are advantageous microhabitats because of their complex architecture. The system of internal canals provides circulation of water and deposition of particulate organic matter, ensuring availability of food and shelter. Diminutive amphipods have little difficulty penetrating the spaces of sponges and remain in their aquiferous systems as one of the most abundant taxa in this association. This study evaluated the temporal variation of the gammaridean amphipod species associated with the sponge Mycale angulosa. Sponge samples were collected every three months over one year at Pontal da Cruz Beach, São Sebastião Channel, southeastern Brazil. The amphipod assembly varied over time, while the amphipod density and sponge biomass remained approximately constant. Six species contributed to the temporal variation infaunal composition, highlighting the importance of the natural history of each species.

  13. Caprellidae (Crustacea: Peracarida: Amphipoda) from the Red Sea and Suez Canal, with the redescription of Metaprotella africana and Paradeutella multispinosa.

    Science.gov (United States)

    Zeina, Amr F; Guerra-García, José M

    2016-04-06

    The Caprellidae from the Red Sea are reviewed based on the literature data and new collections from the Hurghada coasts. So far, only six valid species has been reported from the Red Sea and Suez Canal: Caprella equilibra Say, 1818, Hemiaegina minuta Mayer, 1890, Metaprotella africana Mayer, 1903, Paracaprella pusilla Mayer, 1890 and Paradeutella multispinosa Schellenberg, 1928 and Pseudocaprellina pambanensis Sundara Raj, 1927. The type material of M. africana (deposited in the Muséum nacional d'Histoire naturelle, Paris) and Paradeutella multispinosa (deposited in the Museum für Naturkunde, Berlin) are redescribed and illustrated in detail. P. pambanensis and H. minuta were the most abundant species in the collections along the northern coast. Most of the sampling effort has been focused on algae from shallow waters; additional substrates such as sediments, hydroids and coral rubble, especially from areas deeper than 15 meters should be explored. The number of caprellid species in the Red Sea is low compared to adjacent waters, as the Mediterranean Sea. However, further research and more extensive caprellid collections should be conducted along the coasts of Saudi Arabia, Yemen, Sudan and Eritrea, which are still unexplored.

  14. Grandidierella bonnieroides Stephensen, 1948 (Amphipoda, Aoridae)-first record of an established population in the Mediterranean Sea.

    Science.gov (United States)

    Brutto, Sabrina Lo; Iaciofano, Davide; Lubinevsky, Hadas; Galil, Bella S

    2016-03-17

    The first record in the Mediterranean Sea of the invasive aorid amphipod crustacean Grandidierella bonnieroides is presented. A widespread circumtropical species, recorded off the Saudi coast of the Arabian Gulf, the Red Sea and the Suez Canal, it may have been introduced into the Mediterranean through the Suez Canal. This tube-builder species of soft bottoms recently established a population in the polluted Haifa Bay, Israel. Further, this is the first Mediterranean record of the genus.

  15. DNA barcoding reveals new insights into the diversity of Antarctic species of Orchomene sensu lato (Crustacea: Amphipoda: Lysianassoidea)

    Science.gov (United States)

    Havermans, C.; Nagy, Z. T.; Sonet, G.; De Broyer, C.; Martin, P.

    2011-03-01

    Recent molecular analyses revealed that several so-called "circum-Antarctic" benthic crustacean species appeared to be complexes of cryptic species with restricted distributions. In this study we used a DNA barcoding approach based on mitochondrial cytochrome oxidase I gene sequences in order to detect possible cryptic diversity and to test the circumpolarity of some lysianassoid species. The orchomenid genus complex consists of the genera Abyssorchomene, Falklandia, Orchomenella, Orchomenyx and Pseudorchomene. Species of this genus complex are found throughout the Southern Ocean and show a high species richness and level of endemism. In the majority of the studied species, a genetic homogeneity was found even among specimens from remote sampling sites, which indicates a possible circum-Antarctic and eurybathic distribution. In four investigated species ( Orchomenella ( Orchomenopsis) acanthurus, Orchomenella ( Orchomenopsis) cavimanus, Orchomenella ( Orchomenella) franklini and Orchomenella ( Orchomenella) pinguides), genetically divergent lineages and possible cryptic taxa were revealed. After a detailed morphological analysis, O. ( O.) pinguides appeared to be composed of two distinct species, formerly synonymized under O. ( O.) pinguides. The different genetic patterns observed in these orchomenid species might be explained by the evolutionary histories undergone by these species and by their different dispersal and gene flow capacities.

  16. Aspects of mast building and the fine structure of “amphipod silk” glands in Dyopedos bispinis (Amphipoda, Dulichiidae)

    NARCIS (Netherlands)

    Neretin, N.Y.; Zhadan, A.E.; Tzetlin, A.B.

    2017-01-01

    In the present study, we investigated the biology of Dyopedos bispinis, a mast-building amphipod that is abundant near the N. Pertsov White Sea Biological Station. To examine the peculiarities of mast building in Dyopedos bispinis, we studied the social structure of individuals inhabiting the masts

  17. Effect of gender on physiological and behavioural responses of Gammarus roeseli (Crustacea Amphipoda) to salinity and temperature

    International Nuclear Information System (INIS)

    Sornom, Pascal; Felten, Vincent; Medoc, Vincent; Sroda, Sophie; Rousselle, Philippe; Beisel, Jean-Nicolas

    2010-01-01

    The importance of potentially interacting factors in organisms responses to a stress are often ignored or underestimated in ecotoxicology. In laboratory experiments we investigated how gender, temperature and age influence the behaviour and the physiology of the freshwater amphipod Gammarus roeseli under salinity stress. Our results revealed a significant higher sensitivity of females in survival, ventilation and ionoregulation whereas no inter-age differences were reported. Water temperature also exerted a significant effect in survival and ventilation of G. roeseli. Some of those factors appeared to interact significantly. This study provides evidence that gender can affect organisms responses to a stressor and consequently has to be considered while assessing a stress impact. We discussed the potential relationships between biological and behavioural responses. - Influence of gender, age and temperature in a gammarid responses to a stress.

  18. Temporal and spatial trends in sediment contaminants associated with toxicity in California watersheds

    International Nuclear Information System (INIS)

    Siegler, Katie; Phillips, Bryn M.; Anderson, Brian S.; Voorhees, Jennifer P.; Tjeerdema, Ron S.

    2015-01-01

    California's Stream Pollution Trends program (SPoT) assesses long-term water quality trends, using 100 base-of-the-watershed sampling sites. Annual statewide sediment surveys from 2008 to 2012 identified consistent levels of statewide toxicity (19%), using the freshwater amphipod Hyalella azteca. Significant contaminant trends included a decrease in PCBs, stable concentrations of metals and PAHs, and a statewide increase in detections and concentrations of pyrethroid pesticides. The pyrethroid pesticide bifenthrin was detected in 69% of samples (n = 410). Detection of toxicity increased in a subset of samples tested at a more environmentally relevant test temperature (15 °C), and the magnitude of toxicity was much greater, indicating pyrethroid pesticides as a probable cause. Pyrethroid toxicity thresholds (LC50) were exceeded in 83% of samples with high toxicity. Principal components analysis related pyrethroids, metals and total organic carbon to urban land use. - Highlights: • Toxicity and contaminant concentrations were higher in urban dominated watersheds. • Average and range of total pyrethroid concentrations increased between 2008 and 2012. • Pyrethroid toxicity thresholds (LC50) were exceeded in 83% of samples with high toxicity. - Detections and concentrations of current use pesticides are increasing in California urban watersheds, while legacy organochlorine contaminants are decreasing statewide.

  19. Use of toxicity identification evaluations to determine the pesticide mitigation effectiveness of on-farm vegetated treatment systems

    Energy Technology Data Exchange (ETDEWEB)

    Hunt, John [Department of Environmental Toxicology, University of California, Davis, CA (United States); Department of Environmental Studies, University of California, Santa Cruz, CA (United States); Marine Pollution Studies Laboratory, Granite Canyon, 34500 Highway 1, Monterey, CA 93940 (United States)], E-mail: jwhunt@ucdavis.edu; Anderson, Brian [Department of Environmental Toxicology, University of California, Davis, CA (United States); Marine Pollution Studies Laboratory, Granite Canyon, 34500 Highway 1, Monterey, CA 93940 (United States)], E-mail: anderson@ucdavis.edu; Phillips, Bryn [Department of Environmental Toxicology, University of California, Davis, CA (United States); Marine Pollution Studies Laboratory, Granite Canyon, 34500 Highway 1, Monterey, CA 93940 (United States)], E-mail: bmphillips@ucdavis.edu; Tjeerdema, Ron [Department of Environmental Toxicology, University of California, Davis, CA (United States); Marine Pollution Studies Laboratory, Granite Canyon, 34500 Highway 1, Monterey, CA 93940 (United States)], E-mail: rstjeerdema@ucdavis.edu; Largay, Bryan [Largay Hydrologic Sciences, LLC, 160 Farmer Street Felton, CA 95018-9416 (United States)], E-mail: bryan.largay@sbcglobal.net; Beretti, Melanie [Resources Conservation District of Monterey County, 744-A La Guardia Street, Salinas, CA 93905 (United States)], E-mail: beretti.melanie@rcdmonterey.org; Bern, Amanda [California Regional Water Quality Control Board, Central Coast Region, 895 Aerovista Place, Suite 101, San Luis Obispo, CA 93401 (United States)], E-mail: abern@waterboards.ca.gov

    2008-11-15

    Evidence of ecological impacts from pesticide runoff has prompted installation of vegetated treatment systems (VTS) along the central coast of California, USA. During five surveys of two on-farm VTS ponds, 88% of inlet and outlet water samples were toxic to Ceriodaphnia dubia. Toxicity identification evaluations (TIEs) indicated water toxicity was caused by diazinon at VTS-1, and chlorpyrifos at VTS-2. Diazinon levels in VTS-1 were variable, but high pulse inflow concentrations were reduced through dilution. At VTS-2, chlorpyrifos concentrations averaged 52% lower at the VTS outlet than at the inlet. Water concentrations of most other pesticides averaged 20-90% lower at VTS outlets. All VTS sediment samples were toxic to amphipods (Hyalella azteca). Sediment TIEs indicated toxicity was caused by cypermethrin and lambda-cyhalothrin at VTS-1, and chlorpyrifos and permethrin at VTS-2. As with water, sediment concentrations were lower at VTS outlets, indicating substantial reductions in farm runoff pesticide concentrations. - Toxicity identification evaluations identified key pesticides in agricultural runoff, and their concentrations were reduced by farmer-installed vegetated treatment systems.

  20. A comparison of sediment toxicity test methods at three Great Lake Areas of Concern

    Science.gov (United States)

    Burton, G. Allen; Ingersoll, Christopher G.; Burnett, LouAnn C.; Henry, Mary; Hinman, Mark L.; Klaine, Stephen J.; Landrum, Peter F.; Ross, Phillipe; Tuchman, Marc

    1996-01-01

    The significance of sediment contamination is often evaluated using sediment toxicity (bioassay) testing. There are relatively few “standardized” test methods for evaluating sediments. Popular sediment toxicity methods examine the extractable water (elutriate), interstitial water, or whole (bulk) sediment phases using test species spanning the aquatic food chain from bacteria to fish. The current study was designed to evaluate which toxicity tests were most useful in evaluations of sediment contamination at three Great Lake Areas of Concern. Responses of 24 different organisms including fish, mayflies, amphipods, midges, cladocerans, rotifers, macrophytes, algae, and bacteria were compared using whole sediment or elutriate toxicity assays. Sediments from several sites in the Buffalo River, Calumet River (Indiana Harbor), and Saginaw River were tested, as part of the U.S. Environmental Protection Agency's (USEPA) Assessment and Remediation of Contaminated Sediments (ARCS) Project. Results indicated several assays to be sensitive to sediment toxicity and able to discriminate between differing levels of toxicity. Many of the assay responses were significantly correlated to other toxicity responses and were similar based on factor analysis. For most applications, a test design consisting of two to three assays should adequately detect sediment toxicity, consisting of various groupings of the following species: Hyalella azteca, Ceriodaphnia dubia, Chironomus riparius, Chironomus tentans, Daphnia magna, Pimephales promelas, Hexagenia bilineata, Diporeia sp., Hydrilla verticillata, or Lemna minor.

  1. Toxicity of sediments and pore water from Brunswick Estuary, Georgia

    Science.gov (United States)

    Winger, Parley V.; Lasier, Peter J.; Geitner, Harvey

    1993-01-01

    A chlor-alkali plant in Brunswick, Georgia, USA, discharged >2 kg mercury/d into a tributary of the Turtle River-Brunswick Estuary from 1966 to 1971. Mercury concentrations in sediments collected in 1989 along the tributary near the chlor-alkali plant ranged from 1 to 27 μg/g (dry weight), with the highest concentrations found in surface (0–8 cm) sediments of subtidal zones in the vicinity of the discharge site. Toxicity screening in 1990 using Microtox® bioassays on pore water extracted on site from sediments collected at six stations distributed along the tributary indicated that pore water was highly toxic near the plant discharge. Ten-day toxicity tests on pore water from subsequent sediment samples collected near the plant discharge confirmed high toxicity to Hyalella azteca, and feeding activity was significantly reduced in whole-sediment tests. In addition to mercury in the sediments, other metals (chromium, lead, and zinc) exceeded 50 μg/g, and polychlorobiphenyl (PCB) concentrations ranged from 67 to 95 μg/g. On a molar basis, acid-volatile sulfide concentrations (20–45 μmol/g) in the sediments exceeded the metal concentrations. Because acid-volatile sulfides bind with cationic metals and form metal sulfides, which are generally not bioavailable, toxicities shown by these sediments were attributed to the high concentrations of PCBs and possibly methylmercury.

  2. Assessment of sediment quality in dredged and undredged areas of the Trenton Channel of the Detroit River, Michigan USA, using the sediment quality triad

    Science.gov (United States)

    Besser, John M.; Giesy, John P.; Kubitz, Jody A.; Verbrugge, David A.; Coon, Thomas G.; Braselton, W. Emmett

    1996-01-01

    The “sediment quality triad” approach was used to assess the effects of dredging on the sediment quality of a new marina in the Trenton Channel of the Detroit River, and to evaluate spatial and temporal variation in sediment quality in the Trenton Channel. Samples were collected in November of 1993 (10 months after dredging) and characterized by chemical analysis, sediment bioassays, and assessment of benthic invertebrate communities. The three study components indicated little difference in sediment quality at dredged sites in the marina relative to nearby areas in the Trenton Channel, and little change in sediment quality of Trenton Channel sites relative to conditions reported in the mid-1980s. These results suggest that improvement in sediment quality in the Trenton Channel, due to dredging or natural processes, will depend on elimination of sediment “hot spots” and other upstream contaminant sources. Concentrations of chemical contaminants, especially metals and polycyclic aromatic hydrocarbons, exceeded concentrations associated with effects on biota and were significantly correlated with results of sediment bioassays and characteristics of benthic communities. Laboratory sediment bioassays with Hyalella azteca andChironomus tentans produced better discrimination among sites with differing degrees of contamination than did characterization of benthic communities, which were dominated by oligochaetes at all sites in the marina and the Trenton Channel.

  3. Evidence of lead biomagnification in invertebrate predators from laboratory and field experiments

    International Nuclear Information System (INIS)

    Rubio-Franchini, Isidoro; Rico-Martinez, Roberto

    2011-01-01

    This report includes atomic absorption data from water column, elutriates and zooplankton that demonstrate that lead biomagnifies at El Niagara reservoir, Mexico. Results include field data (bioaccumulation factors) (BAFs) and laboratory data (bioconcentration factors) (BCFs). Two findings: high BAFs for invertebrate predator like Acanthocyclops robustus, Asplanchna brightwellii, Culex sp. larvae, and Hyalella azteca, compared to grazer species Moina micrura and Simocephalus vetulus; low BCF's found for some predators, suggested that lead biomagnifications were taking place. The presence of Moina micrura in the gut of Asplanchna allowed us to design experiments where A. brightwellii was fed lead-exposed M. micrura neonates. The BAF of Asplanchna was 123,684, BCF was 490. Asplanchna individuals fed exposed Moina had 13.31 times more lead than Asplanchna individuals just exposed 48-h to lead, confirming that lead biomagnification occurs. Results of two fish species showed no lead biomagnification, suggesting that lead biomagnification might be restricted to invertebrate predators. - Highlights: → Study shows lead biomagnification evidence in reservoirs where top predators are invertebrates. → Study discusses why in previous studies lead biomagnifications were not detected. → Evidence of biomagnification comes from field and laboratory studies. - This study shows evidence (from field and laboratory experiments) of lead biomagnification in a freshwater reservoir where the main predators are invertebrates.

  4. Pyrethroid insecticides in urban salmon streams of the Pacific Northwest

    Energy Technology Data Exchange (ETDEWEB)

    Weston, D.P., E-mail: dweston@berkeley.edu [Department of Integrative Biology, University of California, 3060 Valley Life Sciences Bldg., Berkeley, CA 94720-3140 (United States); Asbell, A.M., E-mail: aasbell@berkeley.edu [Department of Integrative Biology, University of California, 3060 Valley Life Sciences Bldg., Berkeley, CA 94720-3140 (United States); Hecht, S.A., E-mail: scott.hecht@noaa.gov [NOAA Fisheries, Office of Protected Resources, 510 Desmond Drive S.E., Lacey, WA 98503 (United States); Scholz, N.L., E-mail: nathaniel.scholz@noaa.gov [NOAA Fisheries, Northwest Fisheries Science Center, 2725 Montlake Blvd. E., Seattle, WA 98112 (United States); Lydy, M.J., E-mail: mlydy@siu.edu [Fisheries and Illinois Aquaculture Center and Department of Zoology, Southern Illinois University, 171 Life Sciences II, Carbondale, IL 62901 (United States)

    2011-10-15

    Urban streams of the Pacific Northwest provide spawning and rearing habitat for a variety of salmon species, and food availability for developing salmon could be adversely affected by pesticide residues in these waterbodies. Sediments from Oregon and Washington streams were sampled to determine if current-use pyrethroid insecticides from residential neighborhoods were reaching aquatic habitats, and if they were at concentrations acutely toxic to sensitive invertebrates. Approximately one-third of the 35 sediment samples contained measurable pyrethroids. Bifenthrin was the pyrethroid of greatest concern with regards to aquatic life toxicity, consistent with prior studies elsewhere. Toxicity to Hyalella azteca and/or Chironomus dilutus was found in two sediment samples at standard testing temperature (23 deg. C), and in one additional sample at a more environmentally realistic temperature (13 deg. C). Given the temperature dependency of pyrethroid toxicity, low temperatures typical of northwest streams can increase the potential for toxicity above that indicated by standard testing protocols. - Highlights: > Salmon-bearing creeks can be adversely impacted by insecticides from urban runoff. > Pyrethroid insecticides were found in one-third of the creeks in Washington and Oregon. > Two creeks contained concentrations acutely lethal to sensitive invertebrates. > Bifenthrin was of greatest concern, though less than in prior studies. > Standard toxicity testing underestimates the ecological risk of pyrethroids. - Pyrethroid insecticides are present in sediments of urban creeks of Oregon and Washington, though less commonly than in studies elsewhere in the U.S.

  5. Environmental modeling and exposure assessment of sediment-associated pyrethroids in an agricultural watershed.

    Directory of Open Access Journals (Sweden)

    Yuzhou Luo

    Full Text Available Synthetic pyrethroid insecticides have generated public concerns due to their increasing use and potential effects on aquatic ecosystems. A modeling system was developed in this study for simulating the transport processes and associated sediment toxicity of pyrethroids at coupled field/watershed scales. The model was tested in the Orestimba Creek watershed, an agriculturally intensive area in California' Central Valley. Model predictions were satisfactory when compared with measured suspended solid concentration (R(2 = 0.536, pyrethroid toxic unit (0.576, and cumulative mortality of Hyalella azteca (0.570. The results indicated that sediment toxicity in the study area was strongly related to the concentration of pyrethroids in bed sediment. Bifenthrin was identified as the dominant contributor to the sediment toxicity in recent years, accounting for 50-85% of predicted toxicity units. In addition, more than 90% of the variation on the annual maximum toxic unit of pyrethroids was attributed to precipitation and prior application of bifenthrin in the late irrigation season. As one of the first studies simulating the dynamics and spatial variability of pyrethroids in fields and instreams, the modeling results provided useful information on new policies to be considered with respect to pyrethroid regulation. This study suggested two potential measures to efficiently reduce sediment toxicity by pyrethroids in the study area: [1] limiting bifenthrin use immediately before rainfall season; and [2] implementing conservation practices to retain soil on cropland.

  6. Pyrethroid insecticides in urban salmon streams of the Pacific Northwest

    International Nuclear Information System (INIS)

    Weston, D.P.; Asbell, A.M.; Hecht, S.A.; Scholz, N.L.; Lydy, M.J.

    2011-01-01

    Urban streams of the Pacific Northwest provide spawning and rearing habitat for a variety of salmon species, and food availability for developing salmon could be adversely affected by pesticide residues in these waterbodies. Sediments from Oregon and Washington streams were sampled to determine if current-use pyrethroid insecticides from residential neighborhoods were reaching aquatic habitats, and if they were at concentrations acutely toxic to sensitive invertebrates. Approximately one-third of the 35 sediment samples contained measurable pyrethroids. Bifenthrin was the pyrethroid of greatest concern with regards to aquatic life toxicity, consistent with prior studies elsewhere. Toxicity to Hyalella azteca and/or Chironomus dilutus was found in two sediment samples at standard testing temperature (23 deg. C), and in one additional sample at a more environmentally realistic temperature (13 deg. C). Given the temperature dependency of pyrethroid toxicity, low temperatures typical of northwest streams can increase the potential for toxicity above that indicated by standard testing protocols. - Highlights: → Salmon-bearing creeks can be adversely impacted by insecticides from urban runoff. → Pyrethroid insecticides were found in one-third of the creeks in Washington and Oregon. → Two creeks contained concentrations acutely lethal to sensitive invertebrates. → Bifenthrin was of greatest concern, though less than in prior studies. → Standard toxicity testing underestimates the ecological risk of pyrethroids. - Pyrethroid insecticides are present in sediments of urban creeks of Oregon and Washington, though less commonly than in studies elsewhere in the U.S.

  7. Site-specific sediment clean-up objectives developed by the sediment quality triad

    International Nuclear Information System (INIS)

    Redman, S.; Janisch, T.

    1995-01-01

    Sediment chemistry, sediment toxicity, and benthic macroinvertebrate community data were collected and evaluated in concert (1) to characterize adverse effects of hydrocarbon and metal contaminants in the sediments of a small inlet of Superior Bay, Lake Superior and a tributary creek and (2) to derive numeric objectives for the clean up of this system. Sediments from reference locations and eight study sites were analyzed for a range of contaminants, including hydrocarbons (measured both as diesel range organics (DRO) and oil and grease), lead, chromium, and ammonia. A range of sediment toxicity was observed across the eight study sites using a variety of tests and endpoints: Hyalella azteca (10 day survival and growth), Chironomus tentans (10 day survival and growth), Ceriodaphnia dubia (48 hour survival), and Daphnia magna (48 hour survival and 10 day survival and reproduction). A range of alterations of the benthic macroinvertebrate community compared with communities from reference locations were observed. Benthic community alterations were summarized quantitatively by taxa richness and Shannon-Weiner mean diversity. Lowest effect levels determined through this study included 150 microg/g dry sediment for DRO (as measured in this study) and 40 microg/g dry sediment for lead. Effects thresholds determined through this study included 1,500 microg/g dry sediment for DRO and 90 microg/g dry sediment for lead. These levels and concentrations measured in relevant reference locations are being used to define objectives for sediment clean up in the inlet and creek

  8. Toxicity of carbon nanotubes to freshwater aquatic invertebrates

    Science.gov (United States)

    Mwangi, Joseph N.; Wang, Ning; Ingersoll, Christopher G.; Hardesty, Doug K.; Brunson, Eric L.; Li, Hao; Deng, Baolin

    2012-01-01

    Carbon nanotubes (CNTs) are hydrophobic in nature and thus tend to accumulate in sediments if released into aquatic environments. As part of our overall effort to examine the toxicity of carbon-based nanomaterials to sediment-dwelling invertebrates, we have evaluated the toxicity of different types of CNTs in 14-d water-only exposures to an amphipod (Hyalella azteca), a midge (Chironomus dilutus), an oligochaete (Lumbriculus variegatus), and a mussel (Villosa iris) in advance of conducting whole-sediment toxicity tests with CNTs. The results of these toxicity tests conducted with CNTs added to water showed that 1.00g/L (dry wt) of commercial sources of CNTs significantly reduced the survival or growth of the invertebrates. Toxicity was influenced by the type and source of the CNTs, by whether the materials were precleaned by acid, by whether sonication was used to disperse the materials, and by species of the test organisms. Light and electron microscope imaging of the surviving test organisms showed the presence of CNTs in the gut as well as on the outer surface of the test organisms, although no evidence was observed to show penetration of CNTs through cell membranes. The present study demonstrated that both the metals solubilized from CNTs such as nickel and the "metal-free" CNTs contributed to the toxicity.

  9. Fate and effects of clothianidin in fields using conservation practices.

    Science.gov (United States)

    de Perre, Chloé; Murphy, Tracye M; Lydy, Michael J

    2015-02-01

    Despite the extensive use of the neonicotinoid insecticide clothianidin, and its known toxicity to beneficial insects such as pollinators, little attention has been given to its fate under agricultural field conditions. The present study investigated the fate and toxicity of clothianidin applied every other year as a corn seed-coating at 2 different rates, 0.25 mg/seed and 0.50 mg/seed, in an agricultural field undergoing a corn-soybean annual rotation, and conservation tillage. Concentrations were measured in soil, surface runoff, infiltration, and groundwater from 2011 to 2013. Clothianidin was detected at low concentrations in soil and water throughout the 2-yr corn and soybean rotation. Low and no-tillage had little or no effect on clothianidin concentrations. Laboratory toxicity bioassays were performed on nontarget species, including Daphnia magna, Hyalella azteca, Chironomus dilutus, Pimephales promelas and Eisenia fetida. Risk quotients were calculated from clothianidin concentrations measured in the field and compared with the laboratory toxicity bioassay results to assess the environmental risk of the insecticide. The risk quotient was found to be lower than the level of concern for C. dilutus, which was the most sensitive species tested; therefore, no short-term environmental risk was expected for the species investigated in the present study. © 2014 SETAC.

  10. Use of toxicity identification evaluations to determine the pesticide mitigation effectiveness of on-farm vegetated treatment systems

    International Nuclear Information System (INIS)

    Hunt, John; Anderson, Brian; Phillips, Bryn; Tjeerdema, Ron; Largay, Bryan; Beretti, Melanie; Bern, Amanda

    2008-01-01

    Evidence of ecological impacts from pesticide runoff has prompted installation of vegetated treatment systems (VTS) along the central coast of California, USA. During five surveys of two on-farm VTS ponds, 88% of inlet and outlet water samples were toxic to Ceriodaphnia dubia. Toxicity identification evaluations (TIEs) indicated water toxicity was caused by diazinon at VTS-1, and chlorpyrifos at VTS-2. Diazinon levels in VTS-1 were variable, but high pulse inflow concentrations were reduced through dilution. At VTS-2, chlorpyrifos concentrations averaged 52% lower at the VTS outlet than at the inlet. Water concentrations of most other pesticides averaged 20-90% lower at VTS outlets. All VTS sediment samples were toxic to amphipods (Hyalella azteca). Sediment TIEs indicated toxicity was caused by cypermethrin and lambda-cyhalothrin at VTS-1, and chlorpyrifos and permethrin at VTS-2. As with water, sediment concentrations were lower at VTS outlets, indicating substantial reductions in farm runoff pesticide concentrations. - Toxicity identification evaluations identified key pesticides in agricultural runoff, and their concentrations were reduced by farmer-installed vegetated treatment systems

  11. Catchment liming creates recolonization opportunity for sensitive invertebrates in a smelter impacted landscape

    Directory of Open Access Journals (Sweden)

    John M. Gunn

    2016-04-01

    Full Text Available The response of a sensitive indicator species to the effects of catchment liming was assessed in a lake severely impacted by atmospheric emissions from a metal smelter in Sudbury, Canada. The lake chemistry recovered following the closure of the local smelter and major reductions (approximately 95% in acid and metal emissions from other area smelters, leading to recolonization of the lake with fish and other biota. However, the littoral macrobenthos community remain severely impoverished. The catchment liming sustained improved stream water quality for 20 years after the initial aerial treatment and created a littoral zone hot spot for the recolonization of Hyalella azteca. Colonization at delta sites of untreated catchment drainage areas, in the same lake, were low and highly variable, and these sites appeared to be impacted from soil erosion and episodic release of acid and metals. This study demonstrated the need to both reduce air pollutants and to conduct land reclamation in severely damaged watersheds, before lake ecosystems themselves can be fully recovered.

  12. Identifying the cause of sediment toxicity in agricultural sediments: the role of pyrethroids and nine seldom-measured hydrophobic pesticides.

    Science.gov (United States)

    Weston, Donald P; Ding, Yuping; Zhang, Minghua; Lydy, Michael J

    2013-01-01

    Few currently used agricultural pesticides are routinely monitored for in the environment. Even if concentrations are known, sediment LC(50) values are often lacking for common sediment toxicity testing species. To help fill this data gap, sediments in California's Central Valley were tested for nine hydrophobic pesticides seldom analyzed: abamectin, diazinon, dicofol, fenpropathrin, indoxacarb, methyl parathion, oxyfluorfen, propargite, and pyraclostrobin. Most were detected, but rarely at concentrations acutely toxic to Hyalella azteca or Chironomus dilutus. Only abamectin, fenpropathrin, and methyl parathion were found at concentrations of potential concern, and only in one or two samples. One-quarter of over 100 samples from agriculture-affected waterways exhibited toxicity, and in three-fourths of the toxic samples, pyrethroids exceeded concentrations expected to cause toxicity. The pyrethroid Bi-fen-thrin in particular, as well as lambda-cyhalothrin, cypermethrin, esfenvalerate, permethrin, and the organophosphate chlorpyrifos, were primarily responsible for the observed toxicity, rather than the more novel analytes, despite the fact that much of the sampling targeted areas of greatest use of the novel pesticides. Copyright © 2012 Elsevier Ltd. All rights reserved.

  13. Effects of 2 fungicide formulations on microbial and macroinvertebrate leaf decomposition under laboratory conditions

    Science.gov (United States)

    Elskus, Adria; Smalling, Kelly L.; Hladik, Michelle; Kuivila, Kathryn

    2016-01-01

    Aquatic fungi contribute significantly to the decomposition of leaves in streams, a key ecosystem service. However, little is known about the effects of fungicides on aquatic fungi and macroinvertebrates involved with leaf decomposition. Red maple (Acer rubrum) leaves were conditioned in a stream to acquire microbes (bacteria and fungi), or leached in tap water (unconditioned) to simulate potential reduction of microbial biomass by fungicides. Conditioned leaves were exposed to fungicide formulations QUILT (azoxystrobin + propiconazole) or PRISTINE (boscalid + pyraclostrobin), in the presence and absence of the leaf shredder, Hyalella azteca (amphipods; 7-d old at start of exposures) for 14 d at 23 °C. QUILT formulation (~ 0.3 μg/L, 1.8 μg/L, 8 μg/L) tended to increase leaf decomposition by amphipods (not significant) without a concomitant increase in amphipod biomass, indicating potential increased consumption of leaves with reduced nutritional value. PRISTINE formulation (~ 33 μg/L) significantly reduced amphipod growth and biomass (p<0.05), effects similar to those observed with unconditioned controls. The significant suppressive effects of PRISTINE on amphipod growth, and the trend towards increased leaf decomposition with increasing QUILT concentration, indicate the potential for altered leaf decay in streams exposed to fungicides. Further work is needed to evaluate fungicide effects on leaf decomposition under conditions relevant to stream ecosystems, including temperature shifts and pulsed exposures to pesticide mixtures.

  14. Cadmium risks to freshwater life: derivation and validation of low-effect criteria values using laboratory and field studies

    Science.gov (United States)

    Mebane, Christopher A.

    2006-01-01

    ' criterion) was calculated as 0.75 mug/L cadmium using the hardness-dependent equation CMC = e(0.8403 ? ln(hardness)-3.572) where the 'ln hardness' is the natural logarithm of the water hardness. Likewise, the criterion continuous concentration (CCC, or 'chronic' criterion) was calculated as 0.37 mug/L cadmium using the hardness-dependent equation CCC = (e(0.6247 ? ln(hardness)-3.384)) ? (1.101672 - ((ln hardness) ? 0.041838))). Using data that were independent of those used to derive the criteria, the criteria concentrations were evaluated to estimate whether adverse effects were expected to the biological integrity of natural waters or to selected species listed as threatened or endangered. One species was identified that would not be fully protected by the derived CCC, the amphipod Hyalella azteca. Exposure to CCC conditions likely would lead to population decreases in Hyalella azteca, the food web consequences of which probably would be slight if macroinvertebrate communities were otherwise diverse. Some data also suggested adverse behavioral changes are possible in fish following long-term exposures to low levels of cadmium, particularly in char (genus Salvelinus). Although ambiguous, these data indicate a need to periodically review the literature on behavioral changes in fish following metals exposure as more information becomes available. Most data reviewed indicated that criteria conditions were unlikely to contribute to overt adverse effects to either biological integrity or listed species. If elevated cadmium concentrations that approach the chronic criterion values occur in ambient waters, careful biological monitoring of invertebrate and fish assemblages would be prudent to validate the prediction that the assemblages would not be adversely affected by cadmium at criterion concentrations.

  15. Effects of sediment-spiked lufenuron on benthic macroinvertebrates in outdoor microcosms and single-species toxicity tests

    Energy Technology Data Exchange (ETDEWEB)

    Brock, T.C.M., E-mail: theo.brock@wur.nl [Alterra, Wageningen University and Research Centre, P.O. Box 47, 6700 AA Wageningen (Netherlands); Bas, D.A. [Institute for Biodiversity and Ecosystem Dynamics (IBED), University of Amsterdam (Netherlands); Belgers, J.D.M. [Alterra, Wageningen University and Research Centre, P.O. Box 47, 6700 AA Wageningen (Netherlands); Bibbe, L. [Institute for Biodiversity and Ecosystem Dynamics (IBED), University of Amsterdam (Netherlands); Boerwinkel, M-C.; Crum, S.J.H. [Alterra, Wageningen University and Research Centre, P.O. Box 47, 6700 AA Wageningen (Netherlands); Diepens, N.J. [Department of Aquatic Ecology and Water Quality Management, Wageningen University, P.O. Box 47, 6700 AA Wageningen (Netherlands); Kraak, M.H.S.; Vonk, J.A. [Institute for Biodiversity and Ecosystem Dynamics (IBED), University of Amsterdam (Netherlands); Roessink, I. [Alterra, Wageningen University and Research Centre, P.O. Box 47, 6700 AA Wageningen (Netherlands)

    2016-08-15

    Highlights: • In outdoor microcosms constructed with lufenuron-spiked sediment we observed that this insecticide persistent in the sediment compartment. • Sediment exposure to lufenuron caused population-level declines (insects and crustaceans) and increases (mainly oligochaete worms) of benthic invertebrates. • The direct and indirect effects observed in the microcosms were supported by results of sediment-spiked single species tests with Chironomus riparius, Hyalella azteca and Lumbriculus variegatus. • The tier-1 effect assessment procedure for sediment organisms recommended by the European Food Safety Authority is protective for the treatment-related responses observed in the microcosm test. - Abstract: Sediment ecotoxicity studies were conducted with lufenuron to (i) complement the results of a water-spiked mesocosm experiment with this lipophilic benzoylurea insecticide, (ii) to explore the predictive value of laboratory single-species tests for population and community-level responses of benthic macroinvertebrates, and (iii) to calibrate the tier-1 effect assessment procedure for sediment organisms. For this purpose the concentration-response relationships for macroinvertebrates between sediment-spiked microcosms and those of 28-d sediment-spiked single-species toxicity tests with Chironomus riparius, Hyalella azteca and Lumbriculus variegatus were compared. Lufenuron persisted in the sediment of the microcosms. On average, 87.7% of the initial lufenuron concentration could still be detected in the sediment after 12 weeks. Overall, benthic insects and crustaceans showed treatment-related declines and oligochaetes treatment-related increases. The lowest population-level NOEC in the microcosms was 0.79 μg lufenuron/g organic carbon in dry sediment (μg a.s./g OC) for Tanytarsini, Chironomini and Dero sp. Multivariate analysis of the responses of benthic macroinvertebrates revealed a community-level NOEC of 0.79 μg a.s./g OC. The treatment

  16. Evaluation of the toxicity of sediments from the Anniston PCB Site to the mussel Lampsilis siliquoidea

    Science.gov (United States)

    Schein, Allison; Sinclair, Jesse A.; MacDonald, Donald D.; Ingersoll, Christopher G.; Kemble, Nile E.; Kunz, James L.

    2015-01-01

    concentrations of PCBs were associated with the highest concentrations of PAHs, PCDDs/PCDFs, and organochlorine pesticides. Specifically, sediments 08, 18, and 19 exceeded probable effect concentration quotients (PEC-Qs) of 1.0 for all organic classes of contaminants. These three sediment samples also had high concentrations of mercury and lead, which were the only metals found at elevated concentrations (i.e., above the probable effect concentration [PEC]) in the samples collected. Many sediment samples were highly contaminated with mercury, based on comparisons to samples collected from reference locations. The whole-sediment laboratory toxicity tests conducted with L. siliquoidea met the test acceptability criteria (e.g., control survival was greater than or equal to 80%). Survival of mussels was high in most samples, with 4 of 23 samples (17%) classified as toxic based on the survival endpoint. Biomass and weight were more sensitive endpoints for the L. siliquoidea toxicity tests, with both endpoints classifying 52% of the samples as toxic. Samples 19 and 30 were most toxic to L. siliquoidea, as they were classified as toxic according to all four endpoints (survival, biomass, weight, and length). Mussels were less sensitive in toxicity tests conducted with sediments from the Anniston PCB Site than Hyalella azteca and Chironomus dilutus. Biomass of L. siliquoidea was less sensitive compared to biomass of H. azteca or biomass of larval C. dilutus. Based on the most sensitive endpoint for each species, 52% of the samples were toxic to L. siliquoidea, whereas 67% of sediments were toxic to H. azteca (based on reproduction) and 65% were toxic to C. dilutus (based on adult biomass). The low-risk toxicity threshold (TTLR) was higher for L. siliquoidea biomass (e.g., 20,400 µg/kg dry weight [DW]) compared to that for H. azteca reproduction (e.g., 499 µg/kg DW) or C. dilutus adult biomass (e.g., 1,140 µg/kg DW; MacDonald et al. 2014). While mussels such as L. sili

  17. The Gammarus pulex-group in Italy (Crustacea, Amphipoda) (A study based on material from the Museo Civico di Storia Naturale, Verona)

    NARCIS (Netherlands)

    Goedmakers, Annemarie; Pinkster, Sjouk

    1977-01-01

    A historical review is given of the literature oil Italian members of the genus Gammarus. Only three Gammarus species were known with certainty from Italy, viz G. fossarum Koch, 1836, G. lacustris G.O. Sars, 1863, and G. cf. balcanicus Schäferna, 1922. G. fossarum is widely distributed in the

  18. Kelp forest as a habitat for mobile epifauna: case study of Caprella septentrionalis Kröyer, 1838 (Amphipoda, Caprellidae in an Arctic glacial fjord

    Directory of Open Access Journals (Sweden)

    Marta Ronowicz

    2013-11-01

    Full Text Available Distribution and abundance of the amphipod Caprella septentrionalis in relation to environmental conditions and habitat preferences were investigated in a kelp forest in Hornsund, Spitsbergen. Three sampling sites differed in hydrodynamics, organic and inorganic suspension concentration, and sedimentation rates. None of these abiotic factors or species of a macroalgal host appeared to have a significant influence on C. septentrionalis abundance and size range. An apparent preference towards the blade parts of the algal thalli was observed. These results support the idea of C. septentrionalis as a generalist Arctic–boreal species that takes advantage of the protective nature of kelp forests.

  19. Lípidos en el anfípodo Talorchestia margaritae (Amphipoda: Talitridae y su relación con la ecología de la especie

    Directory of Open Access Journals (Sweden)

    Sandra López

    2010-09-01

    Full Text Available T. margaritae cumple un papel importante en la descomposición de restos vegetales y animales en las costas venezolanas. El objetivo fue determinar las diferencias en la composición lipídica entre sexos y talla de la especie. Para esto, especímenes de T. margaritae fueron recolectados en la zona supralitoral de dos playas arenosas: Mangle Quemao y las Mercedes de Paparo. Posteriormente se separaron por talla y sexo determinándoles su peso, densidad, biomasa y perfil lipídico. Todas las categorías presentaron tallas similares entre localidades. Los pesos fueron superiores en los organismos de Mangle Quemao. Los lípidos totales presentaron proporciones similares entre sexos, talla y localidad (3-5%, al igual que los fosfololípidos (20-30%, glicolípidos (<1% y esteroles (4%, exceptuando los triglicéridos (TAG, siendo estos superiores en Mangle Quemao. Esto último pudiendo estar relacionado con la diferencia de pesos entre localidades. Los ácidos grasos más abundantes en ambas localidades fueron 16:0 y 18:1(n-9. Se identificaron otros 9 marcadores con variaciones en su distribución. Con base en los biomarcadores se puede catalogar a T. margaritae como una especie carnívora- generalista, siendo sus poblaciones influenciadas por la disponibilidad de alimento que a su vez, podría inducir diferencias de peso, TAG y biomarcadores.

  20. A taxonomic revision helps to clarify differences between the Atlantic invasive Ptilohyale littoralis and the Mediterranean endemic Parhyale plumicornis (Crustacea, Amphipoda

    Directory of Open Access Journals (Sweden)

    Sabrina Lo Brutto

    2018-04-01

    Full Text Available Ptilohyale explorator (formerly Parhyale explorator, described by Arresti (1989, can be considered to be a synonym of west-Atlantic Ptilohyale littoralis (Stimpson, 1853, based on morphological observations of paratypes and specimens recently collected in the type locality of Ptilohyale explorator. The first collections of Ptilohyale littoralis, from the eastern Atlantic were from the port of Rotterdam (The Netherlands in 2009 and later in Wimereux, Opal Coast (France in 2014; however, the synonymy of Ptilohyale explorator with Ptilohyale littoralis backdates to the first European record of Ptilohyale littoralis in 1985 at La Vigne, Bay of Arcachon (France. This indicates that Ptilohyale littoralis has been established along European Atlantic coast for many years. An assessment of the nominal valid species belonging to the genus Ptilohyale was carried out and a comparison between the Atlantic Ptilohyale littoralis and the very similar Mediterranean hyalid species, Parhyale plumicornis, is presented based on morphological features and distribution. Due to the invasive ability of Ptilohyale littoralis, a comparison between the two species is necessary.

  1. Benthic amphipods (Amphipoda: Gammaridea and Corophiidea) from the Mexican southeast sector of the Gulf of Mexico: checklist, new records and zoogeographic comments.

    Science.gov (United States)

    Paz-Ríos, Carlos E; Ardisson, Pedro-Luis

    2013-01-01

    The southeast region of the Gulf of Mexico is considered to be biologically important, because it is a connection and transition zone between the Caribbean and the Gulf of Mexico, harboring great marine biodiversity. Nevertheless, benthic amphipods have been poorly studied in the Mexican southeast sector of the Gulf of Mexico with few studies listing species. The aim of this study is to provide an update checklist of species for the Mexican southeast sector (based on literature review and records from the present study) as well as a brief zoogeographical analysis for the Gulf of Mexico amphipod fauna, putting them in context with the fauna on the tropical western Atlantic. Fifty-five species were listed for the Mexican southeast sector; 36 of them showed a geographical extension to the Yucatan continental shelf representing 23 new records for the Mexican southeast sector, nine for the southeast region and four for the Gulf of Mexico. Based on the zoogeographical analysis, there is support of the application of Carolinian and Caribbean zoogeographic provinces to amphipods in the Gulf of Mexico.

  2. Gammarus orinos n. sp. from the Massif Central (France): its genetic and morphological distinction from Gammarus ibericus Margalef, 1951 (Crustacea, Amphipoda)

    NARCIS (Netherlands)

    Pinkster, Sjouk; Scholl, Adolf

    1984-01-01

    Until 1974 Gammarus ibericus was known only from the type-locality in Spain. In that year, Goedmakers recorded the species from many localities in the Massif Central, France. Indeed, these populations show a great morphological resemblance to the Spanish ones. These French populations were used in

  3. Members of the Gammarus pulex-group (Crustacea – Amphipoda) from North Africa and Spain, with description of a new species from Morocco

    NARCIS (Netherlands)

    Pinkster, Sjouk

    1971-01-01

    Gammarus gauthieri (Karaman) was known from North Africa only. During systematic sampling, carried out in 1969 to 1970, it became clear, that the species is also widely distributed in the Iberian peninsula. Comparative descriptions of this species and of two other members of the Gammarus

  4. 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.

  5. Species richness and faunistic affinities of the Gammaridea and Corophiidea (Amphipoda from shallow waters of southern Tierra del Fuego, Argentina: preliminary results

    Directory of Open Access Journals (Sweden)

    Ignacio Luis Chiesa

    2005-12-01

    Full Text Available Species richness and faunistic affinities of gammaridean and corophiidean amphipods from southern Tierra del Fuego were studied. The material was collected with dredges and grabs at 7 locations (15 sampling stations in a range of 5 to 35 m depth. A total of 61 species belonging to 20 families and 43 genera were identified. The genera Cephalophoxoides, Ceradocopsis and Photis are reported for the first time from the Magellan region and 3 species belonging to Atylus, Ischyrocerus and Photis appear to be new to science. Most of the species collected belong to Phoxocephalidae, whereas most individuals were contained in the Stenothoidae and Lysianassidae s.l. The analysis of the faunistic affinities showed that 16 species (39% are endemic to the Magellan region, 9 species (22% extend to the south, 5 species (12.2% to the north and 5 other species (12.2% to both the north and south. In addition, 6 species extend beyond the Magellan region as far as Oceania.

  6. Le genre Victoriopisa signalé pour la première fois en Atlantique Nord: description de V. atlantica nov. sp. de Mauritanie (Crustacea, Amphipoda)

    NARCIS (Netherlands)

    Stock, Jan H.; Platvoet, Dirk

    1981-01-01

    A new species of Victoriopisa, a genus hitherto only known from Australia, India and Southern Africa, has been discovered in the North Atlantic, on intertidal sand flats of the Arguin Bank, Mauritania.

  7. A new marine interstitial psammogammarus (Crustacea, Amphipoda, Melitidae) from Gura Ici Island, off western Halmahera (North Moluccas, Indonesia), and an overview of the genus

    NARCIS (Netherlands)

    Vonk, R.; Hoeksema, B.W.; Jaume, D.

    2011-01-01

    Psammogammarus wallacei sp. n. is described from the shallow marine interstitial of a sand and coral rubble beach on the Gura Ici islands (North Moluccas; Indonesia). This is the first record of this circum-tropical genus from SE Asia, with the geographically closest relative inhabiting the Ryukyu

  8. A new marine interstitial Psammogammarus (Crustacea, Amphipoda, Melitidae from Gura Ici Island, off western Halmahera (North Moluccas, Indonesia, and an overview of the genus

    Directory of Open Access Journals (Sweden)

    Ronald Vonk

    2011-09-01

    Full Text Available Psammogammarus wallacei sp. n. is described from the shallow marine interstitial of a sand and coral rubble beach on the Gura Ici islands (North Moluccas; Indonesia. This is the first record of this circum-tropical genus from SE Asia, with the geographically closest relative inhabiting the Ryukyu archipelago in Japan. The new species is highly distinctive by the display of sexual dimorphism on pleopod II, with the medial margin of the male proximal article of exopod provided with a comb of short, blunt curved spinules; no other representative of the genus is known to display sexually-dimorphic appendages aside of the gnathopods. The new species is also noteworthy by the outline of the palm margin of male gnathopod II, hardly excavated, and by showing a carpus broader than long. An overview of the genus Psammogammarus with 14 species to date is provided.

  9. Population structure of the seaweed dweller Hyale media (Dana) (Amphipoda, Gammaridea, Hyalidae) from Caiobá, Matinhos, Paraná, Brazil

    OpenAIRE

    Dubiaski-Silva, Janete; Masunari, Setuko

    1998-01-01

    A study of correlation between the total body length and the somites length was carried out in a population of Hyale media (Dana, 1857), in order to know which somite or group of somites has the highest correlation index with the total body length. As the sum of the length of the first to fourth pereonites showed the highest linear correlation index (Y=0.0764+0.2736X; r=0.9723), this meristic parameter was chosen to describe the population structure of the species. The following aspects were ...

  10. Nouvelles espèces d’Orchomene s.l. (Crustacea-Amphipoda) des fonds abyssaux. Affinités avec les autres Orchomene profonds

    NARCIS (Netherlands)

    Bellan-Santini, D.

    1990-01-01

    Deux espèces d’ Orchomene aveugles appartenant aux communautés benthiques abyssales sont décrites. O. kaikoi a été récolté dans le grand bivalve Calyptogena (Ectenagena) phaseoliformis provenant des fosses de subduction du Japon. O. stocki provient du lavage d’épongés du genre Cladorhiza récoltées

  11. Evaluation of the impact of farming activity in the water quality in surface catchment areas in hydrographic basin from Mogi-Guacu and Pardo Rivers, Sao Paulo

    International Nuclear Information System (INIS)

    Katsuoka, Lidia

    2001-01-01

    This study was performed in 10 small basins located in the Mogi-Guacu and Pardo Rivers, in the Northeastern area of Sao Paulo State. The land belonging of these basins is used to grow row crops of potato, coffee and pasture areas. This study aimed to characterize small basins, to evaluate water and sediment quality and to correlate basic aspects of climatology, hydrology, toxicology and land uses to the physical, chemical and toxicological characteristics of the water in the streams. Geographic Information System (GIS) was used as a tool of evaluation of land uses and risk assessment was performed for a final evaluation. The samplings were carried out from June/1999 to June/2000 in the 13 collecting points. It was verified that water quality is dependent upon the rainy and dry periods and the harvest periods. In the beginning of rainy periods were found large concentrations of metals and traces of herbicides leachate from soil and, in the dry period the same event was verified, caused by concentration of the water. In August, September and October phosphorus concentrations were very low getting an improvement in the water quality. Al, Fe and Mn are majority elements of chemical compositions of rocks of the study area, and exceed the Brazilian Guidelines. The stream waters were classified as 44% oligotrophic, 42% mesotrophic and 14% eutrophic. Jaguari-Mirim River presented the largest values of Trophic Index (TI). Sediment analyses showed a great variety of organic compounds coming from anthropogenic activities (industrial and farming activity). Toxicity tests with hyalella azteca in the sediments presented toxicity for sediments from Sao Joao da Boa Vista and Divinolandia. A methodology was developed for organochlorinated pesticides by gas chromatography coupled to mass spectrometry (GCMS). The presence of organochlorinated pesticides was not verified. (author)

  12. Fraunhofer Institut fuer Molekularbiologie und Angewandte Oekologie (IME). Annual report 2014/2015

    International Nuclear Information System (INIS)

    2015-01-01

    The Annual report 2014/2015 of the Fraunhofer Institute for molecular biology and applied ecology includes the following contributions: (A) Molecular Biology: TheraSECOURE - Novel immunotherapeutics for targeted cancer therapy; ''MultiNaBel ''- Automated diagnosis of leukemia; Breeding potato for optimized specialty starches; NGS-based zygosity detection in transgenic maize; High-throughput screen ing system for cellulases based on microfluidic devices; Filter aids reduce production costs for plant-derived biopharmaceuticals; Transient expression of recombinant proteins in packed plant cells; ERA-NET Biodiversa EXOTIC project on the invasive harlequin ladybird; AIM-Biotech supported by the Fraunhofer-Max Planck Cooperation program; Metabolic control analysis of the MEP pathway; Metabolic engineering of Clostridium spp. by genomic integration; The Fraunhofer Future Foundation malaria project; Autoantibodies to type 11 collagen as biomarkers of rheumatoid arthritis; Development of a new drug for the treatment of sepsis; Databionic drug research; Structure-based drug design; Neu 2 : competence consortium for multiple sclerosis drug development; Natural compounds from marine fungi for the treatment of cancer; FCR Center for Systems Biotechnology (CSB): Two selected projects; Development and implementation of a plant-derived vaccine against yellow fever. (B) Applied Ecology: Comparison and improvement of laboratory water/sediment test systems; Inter-laboratory comparison of Hyalella Azteca exposure tests lasting 10-42 days; Substance- and matrix-related environmental monitoring of biocides; GERDA-geobased runoff, erosion and drainage risk assessment; The minimum detectable difference and reliability of mesocosm studies; Mechanistic effect models for the ecological risk assessment of pesticides; Molecular biology test for the online analysis of spontaneously-fermented wines; Coupling two test systems to determine the effect of wastewater

  13. Changing patterns in water toxicity associated with current use pesticides in three California agriculture regions.

    Science.gov (United States)

    Anderson, Brian S; Phillips, Bryn M; Voorhees, Jennifer P; Deng, Xin; Geraci, Jeff; Worcester, Karen; Tjeerdema, Ron S

    2018-03-01

    Regulation of agriculture irrigation water discharges in California, USA, is assessed and controlled by its 9 Regional Water Quality Control Boards under the jurisdiction of the California State Water Resources Control Board. Each Regional Water Board has developed programs to control pesticides in runoff as part of the waste discharge requirements implemented through each region's Irrigated Lands Regulatory Program. The present study assessed how pesticide use patterns differ in the Imperial (Imperial County) and the Salinas and Santa Maria (Monterey County) valleys, which host 3 of California's prime agriculture areas. Surface-water toxicity associated with current use pesticides was monitored at several sites in these areas in 2014 and 2015, and results were linked to changes in pesticide use patterns in these areas. Pesticide use patterns appeared to coincide with differences in the way agriculture programs were implemented by the 2 respective Regional Water Quality Control Boards, and these programs differed in the 2 Water Board Regions. Different pesticide use patterns affected the occurrence of pesticides in agriculture runoff, and this influenced toxicity test results. Greater detection frequency and higher concentrations of the organophosphate pesticide chlorpyrifos were detected in agriculture runoff in Imperial County compared to Monterey County, likely due to more rigorous monitoring requirements for growers using this pesticide in Monterey County. Monterey County agriculture runoff contained toxic concentrations of pyrethroid and neonicotinoid pesticides, which impacted amphipods (Hyalella azteca) and midge larvae (Chironomus dilutus) in toxicity tests. Study results illustrate how monitoring strategies need to evolve as regulatory actions affect change in pesticide use and demonstrate the importance of using toxicity test indicator species appropriate for the suite of contaminants in runoff in order to accurately assess environmental risk. Integr

  14. Relationships among exceedences of metals criteria, the results of ambient bioassays, and community metrics in mining-impacted streams.

    Science.gov (United States)

    Griffith, Michael B; Lazorchak, James M; Herlihy, Alan T

    2004-07-01

    If bioassessments are to help diagnose the specific environmental stressors affecting streams, a better understanding is needed of the relationships between community metrics and ambient criteria or ambient bioassays. However, this relationship is not simple, because metrics assess responses at the community level of biological organization, while ambient criteria and ambient bioassays assess or are based on responses at the individual level. For metals, the relationship is further complicated by the influence of other chemical variables, such as hardness, on their bioavailability and toxicity. In 1993 and 1994, U.S. Environmental Protection Agency (U.S. EPA) conducted a Regional Environmental Monitoring and Assessment Program (REMAP) survey on wadeable streams in Colorado's (USA) Southern Rockies Ecoregion. In this ecoregion, mining over the past century has resulted in metals contamination of streams. The surveys collected data on fish and macroinvertebrate assemblages, physical habitat, and sediment and water chemistry and toxicity. These data provide a framework for assessing diagnostic community metrics for specific environmental stressors. We characterized streams as metals-affected based on exceedence of hardness-adjusted criteria for cadmium, copper, lead, and zinc in water; on water toxicity tests (48-h Pimephales promelas and Ceriodaphnia dubia survival); on exceedence of sediment threshold effect levels (TELs); or on sediment toxicity tests (7-d Hyalella azteca survival and growth). Macroinvertebrate and fish metrics were compared among affected and unaffected sites to identify metrics sensitive to metals. Several macroinvertebrate metrics, particularly richness metrics, were less in affected streams, while other metrics were not. This is a function of the sensitivity of the individual metrics to metals effects. Fish metrics were less sensitive to metals because of the low diversity of fish in these streams.

  15. Fraunhofer Institut fuer Molekularbiologie und Angewandte Oekologie (IME). Annual report 2012/2013; Fraunhofer Institut fuer Molekularbiologie und Angewandte Oekologie (IME). Jahresbericht 2012/2013

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2013-03-15

    The Annual report 2012/2013 of the Fraunhofer Institute for molecular biology and applied ecology includes the following contributions: (A) Molecular Biology: A technology platform for human monoclonal antibodies against malaria antigens. Reducing the cold sweetening of potatoes during cold storage. BY2 cell - free lysate: an alternative eucaryotic in vitro translation system. Automated animal cell culture. Improvement of resource-use efficiency and productivity in crop plants. Optimizing transient protein expression in tobacco using predictive models. Microbial master-cell banks for biopharmaceutical production. Development and implementation of a plant-produced vaccine against yellow fever. Insect antennae as in situ biosensors. Communal and individual immunity - their relationship in Tribolium castaneum. A Drosophila model for aging. Analysis of insect transcriptomes, Biofuels: Hexanol production with Clostridia. Application of Targeted Proteomics for Metabolic Engineering of Clostridia. The Fraunhofer Future Foundation Malaria Project. Characterization and validation of predictive human experimental pain models. FCR Center for Systems Biotechnology business areas progress report. (B) Applied Ecology: Transformation/dissolution testing of silver nanoparticles. Effect of silver nanoparticles in the context of sewage sludge used in agriculture. Feasibility of biotic ligand models for routine monitoring. Estimating reasonable application dates related to BBCH crop development stages. Bioconcentration studies with the freshwater amphipod Hyalella azteca. Fish life cycle tests: Static vs. flow-through exposure. Vulnerable fish species for risk assessment of pesticides in Europe. Ecotoxicological testing of armor stones in mesocosms. The effect of wild yeast in traditional wines. Lifestock metabolism studies at Fraunhofer IME. Column generated concentrations of highly-lipophilic test substances.

  16. Fraunhofer Institut fuer Molekularbiologie und Angewandte Oekologie (IME). Annual report 2014/2015; Fraunhofer Institut fuer Molekularbiologie und Angewandte Oekologie (IME). Jahresbericht 2014/2015

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2015-07-01

    The Annual report 2014/2015 of the Fraunhofer Institute for molecular biology and applied ecology includes the following contributions: (A) Molecular Biology: TheraSECOURE - Novel immunotherapeutics for targeted cancer therapy; ''MultiNaBel ''- Automated diagnosis of leukemia; Breeding potato for optimized specialty starches; NGS-based zygosity detection in transgenic maize; High-throughput screen ing system for cellulases based on microfluidic devices; Filter aids reduce production costs for plant-derived biopharmaceuticals; Transient expression of recombinant proteins in packed plant cells; ERA-NET Biodiversa EXOTIC project on the invasive harlequin ladybird; AIM-Biotech supported by the Fraunhofer-Max Planck Cooperation program; Metabolic control analysis of the MEP pathway; Metabolic engineering of Clostridium spp. by genomic integration; The Fraunhofer Future Foundation malaria project; Autoantibodies to type 11 collagen as biomarkers of rheumatoid arthritis; Development of a new drug for the treatment of sepsis; Databionic drug research; Structure-based drug design; Neu{sup 2}: competence consortium for multiple sclerosis drug development; Natural compounds from marine fungi for the treatment of cancer; FCR Center for Systems Biotechnology (CSB): Two selected projects; Development and implementation of a plant-derived vaccine against yellow fever. (B) Applied Ecology: Comparison and improvement of laboratory water/sediment test systems; Inter-laboratory comparison of Hyalella Azteca exposure tests lasting 10-42 days; Substance- and matrix-related environmental monitoring of biocides; GERDA-geobased runoff, erosion and drainage risk assessment; The minimum detectable difference and reliability of mesocosm studies; Mechanistic effect models for the ecological risk assessment of pesticides; Molecular biology test for the online analysis of spontaneously-fermented wines; Coupling two test systems to determine the effect of wastewater

  17. Changing agricultural practices: Potential consequences to aquatic organisms

    Science.gov (United States)

    Lasier, Peter J.; Urich, Matthew L.; Hassan, Sayed M.; Jacobs, Whitney N.; Bringolf, Robert B.; Owens, Kathleen M.

    2016-01-01

    Agricultural practices pose threats to biotic diversity in freshwater systems with increasing use of glyphosate-based herbicides for weed control and animal waste for soil amendment becoming common in many regions. Over the past two decades, these particular agricultural trends have corresponded with marked declines in populations of fish and mussel species in the Upper Conasauga River watershed in Georgia/Tennessee, USA. To investigate the potential role of agriculture in the population declines, surface waters and sediments throughout the basin were tested for toxicity and analyzed for glyphosate, metals, nutrients, and steroid hormones. Assessments of chronic toxicity with Ceriodaphnia dubia and Hyalella azteca indicated that few water or sediment samples were harmful and metal concentrations were generally below impairment levels. Glyphosate was not observed in surface waters, although its primary degradation product, aminomethyl phosphonic acid (AMPA), was detected in 77% of the samples (mean = 509 μg/L, n = 99) and one or both compounds were measured in most sediment samples. Waterborne AMPA concentrations supported an inference that surfactants associated with glyphosate may be present at levels sufficient to affect early life stages of mussels. Nutrient enrichment of surface waters was widespread with nitrate (mean = 0.7 mg NO3-N/L, n = 179) and phosphorus (mean = 275 μg/L, n = 179) exceeding levels associated with eutrophication. Hormone concentrations in sediments were often above those shown to cause endocrine disruption in fish and appear to reflect the widespread application of poultry litter and manure. Observed species declines may be at least partially due to hormones, although excess nutrients and herbicide surfactants may also be implicated.

  18. Biological and chemical characterization of metal bioavailability in sediments from Lake Roosevelt, Columbia River, Washington, USA

    Science.gov (United States)

    Besser, J.M.; Brumbaugh, W.G.; Ivey, C.D.; Ingersoll, C.G.; Moran, P.W.

    2008-01-01

    We studied the bioavailability and toxicity of copper, zinc, arsenic, cadmium, and lead in sediments from Lake Roosevelt (LR), a reservoir on the Columbia River in Washington, USA that receives inputs of metals from an upstream smelter facility. We characterized chronic sediment toxicity, metal bioaccumulation, and metal concentrations in sediment and pore water from eight study sites: one site upstream in the Columbia River, six sites in the reservoir, and a reference site in an uncontaminated tributary. Total recoverable metal concentrations in LR sediments generally decreased from upstream to downstream in the study area, but sediments from two sites in the reservoir had metal concentrations much lower than adjacent reservoir sites and similar to the reference site, apparently due to erosion of uncontaminated bank soils. Concentrations of acid-volatile sulfide in LR sediments were too low to provide strong controls on metal bioavailability, and selective sediment extractions indicated that metals in most LR sediments were primarily associated with iron and manganese oxides. Oligochaetes (Lumbriculus variegatus) accumulated greatest concentrations of copper from the river sediment, and greatest concentrations of arsenic, cadmium, and lead from reservoir sediments. Chronic toxic effects on amphipods (Hyalella azteca; reduced survival) and midge larvae (Chironomus dilutus; reduced growth) in whole-sediment exposures were generally consistent with predictions of metal toxicity based on empirical and equilibrium partitioning-based sediment quality guidelines. Elevated metal concentrations in pore waters of some LR sediments suggested that metals released from iron and manganese oxides under anoxic conditions contributed to metal bioaccumulation and toxicity. Results of both chemical and biological assays indicate that metals in sediments from both riverine and reservoir habitats of Lake Roosevelt are available to benthic invertebrates. These findings will be used as

  19. Neonicotinoids in the Canadian aquatic environment: a literature review on current use products with a focus on fate, exposure, and biological effects.

    Science.gov (United States)

    Anderson, J C; Dubetz, C; Palace, V P

    2015-02-01

    Developed to replace organophosphate and carbamate insecticides, neonicotinoids are structurally similar to nicotine. The three main neonicotinoid insecticides, imidacloprid, clothianidin, and thiamethoxam, are being re-evaluated by Health Canada's Pest Management Regulatory Agency (PMRA). An important aspect of the re-evaluation is the potential for effects in non-target organisms, including aquatic organisms. Leaching into surface waters is one of the major concerns surrounding extensive use of neonicotinoids, especially in close proximity to water bodies. The PMRA has classified IMI as 'persistent' with a 'high' leaching potential. Globally, neonicotinoids have been detected in a variety of water bodies, typically at concentrations in the low μg/L range. While IMI has been included in some monitoring exercises, there are currently very few published data for the presence of CLO and THM in Canadian water bodies. The majority of neonicotinoid toxicity studies have been conducted with IMI due to its longer presence on the market and high prevalence of use. Aquatic insects are particularly vulnerable to neonicotinoids and chronic toxicity has been observed at concentrations of IMI below 1 μg/L. Acute toxicity has been reported at concentrations below 20 μg/L for the most sensitive species, including Hyalella azteca, ostracods, and Chironomus riparius. Fish, algae, amphibians, and molluscs are relatively insensitive to IMI. However, the biological effects of THM and CLO have not been as well explored. The Canadian interim water quality guideline for IMI is 0.23 μg/L, but there is currently insufficient use, fate, and toxicological information available to establish guidelines for CLO and THM. Based on concentrations of neonicotinoids reported in surface waters in Canada and globally, there is potential for aquatic invertebrates to be negatively impacted by neonicotinoids. Therefore, it is necessary to address knowledge gaps to inform decisions around guidelines

  20. Development of a sample preparation method for the analysis of current-use pesticides in sediment using gas chromatography.

    Science.gov (United States)

    Wang, Dongli; Weston, Donald P; Ding, Yuping; Lydy, Michael J

    2010-02-01

    Pyrethroid insecticides have been implicated as the cause of sediment toxicity to Hyalella azteca in both agricultural and urban areas of California; however, for a subset of these toxic sediments (approximately 30%), the cause of toxicity remains unidentified. This article describes the analytical method development for seven additional pesticides that are being examined to determine if they might play a role in the unexplained toxicity. A pressurized liquid extraction method was optimized to simultaneously extract diazinon, methyl parathion, oxyfluorfen, dicofol, fenpropathrin, pyraclostrobin, and indoxacarb from sediment, and the extracts were cleaned using a two-step solid-phase extraction procedure. The final extract was analyzed for the target pesticides by gas chromatography/nitrogen-phosphorus detector (GC/NPD), and gas chromatography/electron capture detector (GC/ECD), after sulfur was removed by shaking with copper and cold crystallization. Three sediments were used as reference matrices to assess method accuracy and precision. Method detection limits were 0.23-1.8 ng/g dry sediment using seven replicates of sediment spiked at 1.0 ng/g dry sediment. Recoveries ranged from 61.6 to 118% with relative standard deviations of 2.1-17% when spiked at 5.0 and 50 ng/g dry sediment. The three reference sediments, spiked with 50 ng/g dry weight of the pesticide mixture, were aged for 0.25, 1, 4, 7, and 14 days. Recoveries of the pesticides in the sediments generally decreased with increased aging time, but the magnitude of the decline was pesticide and sediment dependent. The developed method was applied to field-collected sediments from the Central Valley of California.

  1. Development and application of freshwater sediment-toxicity benchmarks for currently used pesticides

    Science.gov (United States)

    Nowell, Lisa H.; Norman, Julia E.; Ingersoll, Christopher G.; Moran, Patrick W.

    2016-01-01

    Sediment-toxicity benchmarks are needed to interpret the biological significance of currently used pesticides detected in whole sediments. Two types of freshwater sediment benchmarks for pesticides were developed using spiked-sediment bioassay (SSB) data from the literature. These benchmarks can be used to interpret sediment-toxicity data or to assess the potential toxicity of pesticides in whole sediment. The Likely Effect Benchmark (LEB) defines a pesticide concentration in whole sediment above which there is a high probability of adverse effects on benthic invertebrates, and the Threshold Effect Benchmark (TEB) defines a concentration below which adverse effects are unlikely. For compounds without available SSBs, benchmarks were estimated using equilibrium partitioning (EqP). When a sediment sample contains a pesticide mixture, benchmark quotients can be summed for all detected pesticides to produce an indicator of potential toxicity for that mixture. Benchmarks were developed for 48 pesticide compounds using SSB data and 81 compounds using the EqP approach. In an example application, data for pesticides measured in sediment from 197 streams across the United States were evaluated using these benchmarks, and compared to measured toxicity from whole-sediment toxicity tests conducted with the amphipod Hyalella azteca (28-d exposures) and the midge Chironomus dilutus (10-d exposures). Amphipod survival, weight, and biomass were significantly and inversely related to summed benchmark quotients, whereas midge survival, weight, and biomass showed no relationship to benchmarks. Samples with LEB exceedances were rare (n = 3), but all were toxic to amphipods (i.e., significantly different from control). Significant toxicity to amphipods was observed for 72% of samples exceeding one or more TEBs, compared to 18% of samples below all TEBs. Factors affecting toxicity below TEBs may include the presence of contaminants other than pesticides, physical

  2. Salinization triggers a trophic cascade in experimental freshwater communities with varying food-chain length.

    Science.gov (United States)

    Hintz, William D; Mattes, Brian M; Schuler, Matthew S; Jones, Devin K; Stoler, Aaron B; Lind, Lovisa; Relyea, Rick A

    2017-04-01

    The application of road deicing salts in northern regions worldwide is changing the chemical environment of freshwater ecosystems. Chloride levels in many lakes, streams, and wetlands exceed the chronic and acute thresholds established by the United States and Canada for the protection of freshwater biota. Few studies have identified the impacts of deicing salts in stream and wetland communities and none have examined impacts in lake communities. We tested how relevant concentrations of road salt (15, 100, 250, 500, and 1000 mg Cl - /L) interacted with experimental communities containing two or three trophic levels (i.e., no fish vs. predatory fish). We hypothesized that road salt and fish would have a negative synergistic effect on zooplankton, which would then induce a trophic cascade. We tested this hypothesis in outdoor mesocosms containing filamentous algae, periphyton, phytoplankton, zooplankton, several macroinvertebrate species, and fish. We found that the presence of fish and high salt had a negative synergistic effect on the zooplankton community, which in turn caused an increase in phytoplankton. Contributing to the magnitude of this trophic cascade was a direct positive effect of high salinity on phytoplankton abundance. Cascading effects were limited with respect to impacts on the benthic food web. Periphyton and snail grazers were unaffected by the salt-induced trophic cascade, but the biomass of filamentous algae decreased as a result of competition with phytoplankton for light or nutrients. We also found direct negative effects of high salinity on the biomass of filamentous algae and amphipods (Hyalella azteca) and the mortality of banded mystery snails (Viviparus georgianus) and fingernail clams (Sphaerium simile). Clam mortality was dependent on the presence of fish, suggesting a non-consumptive interactive effect with salt. Our results indicate that globally increasing concentrations of road salt can alter community structure via both direct

  3. Evaluation of metals, metalloids, and ash mixture toxicity using sediment toxicity testing.

    Science.gov (United States)

    Stojak, Amber; Bonnevie, Nancy L; Jones, Daniel S

    2015-01-01

    In December 2008, a release of 4.1 million m(3) of coal ash from the Tennessee Valley Authority Kingston Fossil Plant occurred. Ash washed into the Emory River and migrated downstream into the Clinch and Tennessee Rivers. A Baseline Ecological Risk Assessment evaluated risks to ecological receptors from ash in the river system post-dredging. This article describes the approach used and results from sediment toxicity tests, discussing any causal relationships between ash, metals, and toxicity. Literature is limited in the realm of aquatic coal combustion residue (CCR) exposures and the potential magnitude of effects on benthic invertebrates. Sediment samples along a spectrum of ash content were used in a tiered toxicity testing approach and included a combination of 10 day sediment toxicity acute tests and longer-term, partial life cycle "definitive" tests with 2 species (Hyalella azteca and Chironomus dilutus). Arsenic, and to a lesser extent Se, in the ash was the most likely toxicant causing observed effects in the laboratory toxicity tests. Sites in the Emory River with the greatest statistical and biologically significant effects had As concentrations in sediments twice the probable effects concentration of 33 mg/kg. These sites contained greater than 50% ash. Sites with less than approximately 50% ash in sediments exhibited fewer significant toxic responses relative to the reference sediment in the laboratory. The results discussed here present useful evidence of only limited effects occurring from a worst-case exposure pathway. These results provided a valuable line of evidence for the overall assessment of risks to benthic invertebrates and to other ecological receptors, and were crucial to risk management and development of project remediation goals. © 2014 SETAC.

  4. Toxicity of silicon carbide nanowires to sediment-dwelling invertebrates in water or sediment exposures

    Science.gov (United States)

    Mwangi, Joseph N.; Wang, Ning; Ritts, Andrew; Kunz, James L.; Ingersoll, Christopher G.; Li, Hao; Deng, Baolin

    2011-01-01

    Silicon carbide nanowires (SiCNW) are insoluble in water. When released into an aquatic environment, SiCNW would likely accumulate in sediment. The objective of this study was to assess the toxicity of SiCNW to four freshwater sediment-dwelling organisms: amphipods (Hyalella azteca), midges (Chironomus dilutus), oligochaetes (Lumbriculus variegatus), and mussels (Lampsilis siliquoidea). Amphipods were exposed to either sonicated or nonsonicated SiCNW in water (1.0 g/L) for 48 h. Midges, mussels, and oligochaetes were exposed only to sonicated SiCNW in water for 96 h. In addition, amphipods were exposed to sonicated SiCNW in whole sediment for 10 d (44% SiCNW on dry wt basis). Mean 48-h survival of amphipods exposed to nonsonicated SiCNW in water was not significantly different from the control, whereas mean survival of amphipods exposed to sonicated SiCNW in two 48-h exposures (0 or 15% survival) was significantly different from the control (90 or 98% survival). In contrast, no effect of sonicated SiCNW was observed on survival of midges, mussels, or oligochaetes. Survival of amphipods was not significantly reduced in 10-d exposures to sonicated SiCNW either mixed in the sediment or layered on the sediment surface. However, significant reduction in amphipod biomass was observed with the SiCNW either mixed in sediment or layered on the sediment surface, and the reduction was more pronounced for SiCNW layered on the sediment. These results indicated that, under the experimental conditions, nonsonicated SiCNW in water were not acutely toxic to amphipods, sonicated SiCNW in water were acutely toxic to the amphipods, but not to other organisms tested, and sonicated SiCNW in sediment affected the growth but not the survival of amphipods.

  5. Influence of pH on the acute toxicity of ammonia to juvenile freshwater mussels (fatmucket, Lampsills siliquoidea)

    Science.gov (United States)

    Wang, N.; Erickson, R.J.; Ingersoll, C.G.; Ivey, C.D.; Brunson, E.L.; Augspurger, T.; Barnhart, M.C.

    2008-01-01

    The objective of the present study was to evaluate the influence of pH on the toxicity of ammonia to juvenile freshwater mussels. Acute 96-h ammonia toxicity tests were conducted with 10-d-old juvenile mussels (fatmucket, Lampsilis siliquoidea) at five pH levels ranging from 6.5 to 9.0 in flow-through diluter systems at 20??C. Acute 48-h tests with amphipods (Hyalella azteca) and 96-h tests with oligochaetes (Lumbriculus variegatus) were conducted concurrently under the same test conditions to determine the sensitivity of mussels relative to these two commonly tested benthic invertebrate species. During the exposure, pH levels were maintained within 0.1 of a pH unit and ammonia concentrations were relatively constant through time (coefficient of variation for ammonia concentrations ranged from 2 to 30% with a median value of 7.9%). The median effective concentrations (EC50s) of total ammonia nitrogen (N) for mussels were at least two to six times lower than the EC50s for amphipods and oligochaetes, and the EC50s for mussels decreased with increasing pH and ranged from 88 mg N/L at pH 6.6 to 0.96 mg N/L at pH 9.0. The EC50s for mussels were at or below the final acute values used to derive the U.S. Environmental Protection Agency's acute water quality criterion (WQC). However, the quantitative relationship between pH and ammonia toxicity to juvenile mussels was similar to the average relationship for other taxa reported in the WQC. These results indicate that including mussel toxicity data in a revision to the WQC would lower the acute criterion but not change the WQC mathematical representation of the relative effect of pH on ammonia toxicity. ?? 2008 SETAC.

  6. Estrutura populacional de Hyale media (Dana (Amphipoda, Gammaridea, Hyalidae, habitante dos fitais de Caiobá, Matinhos, Paraná, Brasil Population structure of the seaweed dweller Hyale media (Dana (Amphipoda, Gammaridea, Hyalidae from Caiobá, Matinhos, Paraná, Brazil

    Directory of Open Access Journals (Sweden)

    Janete Dubiaski-Silva

    1998-01-01

    Full Text Available A study of correlation between the total body length and the somites length was carried out in a population of Hyale media (Dana, 1857, in order to know which somite or group of somites has the highest correlation index with the total body length. As the sum of the length of the first to fourth pereonites showed the highest linear correlation index (Y=0.0764+0.2736X; r=0.9723, this meristic parameter was chosen to describe the population structure of the species. The following aspects were treated: distribution of the body size classes in the various phytals, population composition, seasonal fluctuation of population density. relative frequency of the ovigerous females and correlation between the body length and the number of eggs inside the marsupium of the ovigerous females. The amphipods were obtained from the seasonal collections of six phytals from a rocky seashore of Caiobá, Paraná State: Pterosiphonia pennata (Roth Falkenberg. Gymrogongrus griffithsiae (Turner Martius, Pterocladia capillacea (Gmelin Bornet & Thured, Sargassum cymosum Garth, Gelidium sp and Ulva fasciata Delile; they did not occurred in Padina gymnospora (Kútsing Vickers and Porphyra atropurpurea (Olivi De Toni. The air temperature oscillated from 16ºC (winter and autumn to 23ºC (summer, the surface water temperature from 17ºC (winter to 25ºC (summer and the surface water salinity, from 29.3‰ (autumn to 32.8‰ (winter. The density oi Hyale media varied from 0.20 ind.g-1 (in Ulva to 26.37 ind.g-1 (in Pterosiphonia of alga-substratum weigth, and the population was distributed mainly in branched algae. It was determined three size classes in the population, within a range from 0.01 to 2.99mm of pereonits 1-4 length. Small amphipods prefer finely branched algae like Gymnogongrusand Pterosiphonia, whereas broad-thallii or less branched algae such as Sargassum, Pterocladia, Gelidium and Ulva harbour proporcionally high number of large individuais. The life cycle of Hyale media takes place wholly in the phytals and the species reproduces continually all year round: males, ovigerous females and juveniles are present every season. The highest femalc reproductive activity occurs in winter and the juveniles are more numerous in summer. The number of eggs inside the marsupium and the pereonites 1-4 length has a linear correlation (Y=-9,9682+12,0729X; r=0.8024.

  7. La fauna de caprélidos (Crustacea: Amphipoda: Caprellidea de la costa de Coquimbo, centro-norte de Chile, con una clave taxonómica para la identificación de las especies The caprellid fauna (Crustacea: Amphipoda: Caprellidea from the coast of Coquimbo, Northern-central Chile, with a taxonomic key for species identification

    Directory of Open Access Journals (Sweden)

    JOSÉ M. GUERRA-GARCÍA

    2001-12-01

    Full Text Available Los caprélidos son comunes y abundantes en muchos hábitats litorales del ambiente marino. Sin embargo este grupo de anfípodos no ha sido muy bien estudiado en la costa chilena. El estudio de los caprélidos se ha visto dificultado por su gran variabilidad morfológica y el hecho de que la literatura así como los especímenes de los museos son difíciles de localizar. El objetivo de este estudio fue entregar las herramientas taxonómicas para la identificación de las especies de crustáceos caprélidos comunes en el centro-norte de la costa de Chile. Se muestrearon distintos hábitats (boyas, bolones intermareales, praderas de algas y fanerógamas marinas y se encontraron seis especies distintas de caprélidos: Caprellina longicollis (Nicolet, 1849, Caprella equilibra Say, 1818, C. scaura Templeton, 1836, C. verrucosa Boeck, 1871; Deutella venenosa Mayer, 1890 y Paracaprella pusilla Mayer, 1890. Caprella scaura, C. verrucosa y D. venenosa fueron muy abundantes sobre las algas, hidrozoos y briozoos asociados a boyas. Caprella equilibra, también presente en boyas, fue más abundante bajo piedras en zonas intermareales rocosas expuestas, donde también se encontraron ejemplares de D. venenosa y de P. pusilla. Caprella scaura también se encontró sobre algas rojas de las playas arenosas, especialmente sobre Gracilaria chilensis y sobre la fanerógama marina Heterozostera tasmanica, donde cohabitó junto a Caprellina longicollis. Paracaprella pusilla constituye una nueva cita para las costas pacíficas sudamericanas, siendo nueva para la fauna de Chile. La especie D. venenosa, que se cita por primera vez después de la descripción original de Mayer en el año 1890, es considerada una especie endémica de la costa central de ChileCaprellids are abundant in many littoral habitats of the marine environment. Nevertheless, this group of amphipods has been scarcely studied along the coast of Chile. The study of the Caprellidea is particularly difficult due to the high degree of intra-specific morphological variability and the fact that literature and specimens from Museums are not easily located. The objective of the present study was to provide the taxonomical tools to identify the most common caprellid species from northern-central Chile. Several habitats were examined (buoys, boulders, algal/seagrass beds and six caprellid species were found: Caprellina longicollis (Nicolet, 1849, Caprella equilibra Say, 1818, C. scaura Templeton, 1836, C. verrucosa Boeck, 1871; Deutella venenosa Mayer, 1890 and Paracaprella pusilla Mayer, 1890. Caprella scaura, C. verrucosa and D. venenosa were most abundant among algae, hydrozoans and bryozoans growing on buoys. Caprella equilibra, also present on buoys, was most abundant underneath boulders in exposed rocky intertidal zones, where additionally D. venenosa and P. pusilla were found. Caprella scaura was dominant in plant beds above sandy subtidal bottom, especially among the alga Gracilaria chilensis and the seagrass Heterozostera tasmanica, where it occurred together with Caprellina longicollis. Paracaprella pusilla represents a new citation for the pacific coasts of S-America, being a new record for Chile. The species D. venenosa, which was recorded for the first time since the original description by Mayer in the year 1890, is considered an endemic species from the central coast of Chile

  8. Impacts of pesticides in a Central California estuary.

    Science.gov (United States)

    Anderson, Brian; Phillips, Bryn; Hunt, John; Siegler, Katie; Voorhees, Jennifer; Smalling, Kelly; Kuivila, Kathy; Hamilton, Mary; Ranasinghe, J Ananda; Tjeerdema, Ron

    2014-03-01

    Recent and past studies have documented the prevalence of pyrethroid and organophosphate pesticides in urban and agricultural watersheds in California. While toxic concentrations of these pesticides have been found in freshwater systems, there has been little research into their impacts in marine receiving waters. Our study investigated pesticide impacts in the Santa Maria River estuary, which provides critical habitat to numerous aquatic, terrestrial, and avian species on the central California coast. Runoff from irrigated agriculture constitutes a significant portion of Santa Maria River flow during most of the year, and a number of studies have documented pesticide occurrence and biological impacts in this watershed. Our study extended into the Santa Maria watershed coastal zone and measured pesticide concentrations throughout the estuary, including the water column and sediments. Biological effects were measured at the organism and community levels. Results of this study suggest the Santa Maria River estuary is impacted by current-use pesticides. The majority of water samples were highly toxic to invertebrates (Ceriodaphnia dubia and Hyalella azteca), and chemistry evidence suggests toxicity was associated with the organophosphate pesticide chlorpyrifos, pyrethroid pesticides, or mixtures of both classes of pesticides. A high percentage of sediment samples were also toxic in this estuary, and sediment toxicity occurred when mixtures of chlorpyrifos and pyrethroid pesticides exceeded established toxicity thresholds. Based on a Relative Benthic Index, Santa Maria estuary stations where benthic macroinvertebrate communities were assessed were degraded. Impacts in the Santa Maria River estuary were likely due to the proximity of this system to Orcutt Creek, the tributary which accounts for most of the flow to the lower Santa Maria River. Water and sediment samples from Orcutt Creek were highly toxic to invertebrates due to mixtures of the same pesticides measured

  9. Development and application of freshwater sediment-toxicity benchmarks for currently used pesticides

    Energy Technology Data Exchange (ETDEWEB)

    Nowell, Lisa H., E-mail: lhnowell@usgs.gov [U.S. Geological Survey, California Water Science Center, Placer Hall, 6000 J Street, Sacramento, CA 95819 (United States); Norman, Julia E., E-mail: jnorman@usgs.gov [U.S. Geological Survey, Oregon Water Science Center, 2130 SW 5" t" h Avenue, Portland, OR 97201 (United States); Ingersoll, Christopher G., E-mail: cingersoll@usgs.gov [U.S. Geological Survey, Columbia Environmental Research Center, 4200 New Haven Road, Columbia, MO 65021 (United States); Moran, Patrick W., E-mail: pwmoran@usgs.gov [U.S. Geological Survey, Washington Water Science Center, 934 Broadway, Suite 300, Tacoma, WA 98402 (United States)

    2016-04-15

    Sediment-toxicity benchmarks are needed to interpret the biological significance of currently used pesticides detected in whole sediments. Two types of freshwater sediment benchmarks for pesticides were developed using spiked-sediment bioassay (SSB) data from the literature. These benchmarks can be used to interpret sediment-toxicity data or to assess the potential toxicity of pesticides in whole sediment. The Likely Effect Benchmark (LEB) defines a pesticide concentration in whole sediment above which there is a high probability of adverse effects on benthic invertebrates, and the Threshold Effect Benchmark (TEB) defines a concentration below which adverse effects are unlikely. For compounds without available SSBs, benchmarks were estimated using equilibrium partitioning (EqP). When a sediment sample contains a pesticide mixture, benchmark quotients can be summed for all detected pesticides to produce an indicator of potential toxicity for that mixture. Benchmarks were developed for 48 pesticide compounds using SSB data and 81 compounds using the EqP approach. In an example application, data for pesticides measured in sediment from 197 streams across the United States were evaluated using these benchmarks, and compared to measured toxicity from whole-sediment toxicity tests conducted with the amphipod Hyalella azteca (28-d exposures) and the midge Chironomus dilutus (10-d exposures). Amphipod survival, weight, and biomass were significantly and inversely related to summed benchmark quotients, whereas midge survival, weight, and biomass showed no relationship to benchmarks. Samples with LEB exceedances were rare (n = 3), but all were toxic to amphipods (i.e., significantly different from control). Significant toxicity to amphipods was observed for 72% of samples exceeding one or more TEBs, compared to 18% of samples below all TEBs. Factors affecting toxicity below TEBs may include the presence of contaminants other than pesticides, physical/chemical characteristics

  10. Toxicity of sediments potentially contaminated by coal mining and natural gas extraction to unionid mussels and commonly tested benthic invertebrates

    Science.gov (United States)

    Wang, Ning; Ingersoll, Christopher G.; Kunz, James L.; Brumbaugh, William G.; Kane, Cindy M.; Evans, R. Brian; Alexander, Steven; Walker, Craig; Bakaletz, Steve

    2013-01-01

    Sediment toxicity tests were conducted to assess potential effects of contaminants associated with coal mining or natural gas extraction activities in the upper Tennessee River basin and eastern Cumberland River basin in the United States. Test species included two unionid mussels (rainbow mussel, Villosa iris, and wavy-rayed lampmussel, Lampsilis fasciola, 28-d exposures), and the commonly tested amphipod, Hyalella azteca (28-d exposure) and midge, Chironomus dilutus (10-d exposure). Sediments were collected from seven test sites with mussel communities classified as impacted and in proximity to coal mining or gas extraction activities, and from five reference sites with mussel communities classified as not impacted and no or limited coal mining or gas extraction activities. Additional samples were collected from six test sites potentially with high concentrations of polycyclic aromatic hydrocarbons (PAHs) and from a test site contaminated by a coal ash spill. Mean survival, length, or biomass of one or more test species was reduced in 10 of 14 test samples (71%) from impacted areas relative to the response of organisms in the five reference samples. A higher proportion of samples was classified as toxic to mussels (63% for rainbow mussels, 50% for wavy-rayed lampmussels) compared with amphipods (38%) or midge (38%). Concentrations of total recoverable metals and total PAHs in sediments did not exceed effects-based probable effect concentrations (PECs). However, the survival, length, or biomasses of the mussels were reduced significantly with increasing PEC quotients for metals and for total PAHs, or with increasing sum equilibrium-partitioning sediment benchmark toxic units for PAHs. The growth of the rainbow mussel also significantly decreased with increasing concentrations of a major anion (chloride) and major cations (calcium and magnesium) in sediment pore water. Results of the present study indicated that (1) the findings from laboratory tests were generally

  11. Development and application of freshwater sediment-toxicity benchmarks for currently used pesticides

    International Nuclear Information System (INIS)

    Nowell, Lisa H.; Norman, Julia E.; Ingersoll, Christopher G.; Moran, Patrick W.

    2016-01-01

    Sediment-toxicity benchmarks are needed to interpret the biological significance of currently used pesticides detected in whole sediments. Two types of freshwater sediment benchmarks for pesticides were developed using spiked-sediment bioassay (SSB) data from the literature. These benchmarks can be used to interpret sediment-toxicity data or to assess the potential toxicity of pesticides in whole sediment. The Likely Effect Benchmark (LEB) defines a pesticide concentration in whole sediment above which there is a high probability of adverse effects on benthic invertebrates, and the Threshold Effect Benchmark (TEB) defines a concentration below which adverse effects are unlikely. For compounds without available SSBs, benchmarks were estimated using equilibrium partitioning (EqP). When a sediment sample contains a pesticide mixture, benchmark quotients can be summed for all detected pesticides to produce an indicator of potential toxicity for that mixture. Benchmarks were developed for 48 pesticide compounds using SSB data and 81 compounds using the EqP approach. In an example application, data for pesticides measured in sediment from 197 streams across the United States were evaluated using these benchmarks, and compared to measured toxicity from whole-sediment toxicity tests conducted with the amphipod Hyalella azteca (28-d exposures) and the midge Chironomus dilutus (10-d exposures). Amphipod survival, weight, and biomass were significantly and inversely related to summed benchmark quotients, whereas midge survival, weight, and biomass showed no relationship to benchmarks. Samples with LEB exceedances were rare (n = 3), but all were toxic to amphipods (i.e., significantly different from control). Significant toxicity to amphipods was observed for 72% of samples exceeding one or more TEBs, compared to 18% of samples below all TEBs. Factors affecting toxicity below TEBs may include the presence of contaminants other than pesticides, physical/chemical characteristics

  12. Occurrence, compositional distribution, and toxicity assessment of pyrethroid insecticides in sediments from the fluvial systems of Chaohu Lake, Eastern China.

    Science.gov (United States)

    Wang, Ji-Zhong; Bai, Ya-Shu; Wu, Yakton; Zhang, Shuo; Chen, Tian-Hu; Peng, Shu-Chuan; Xie, Yu-Wei; Zhang, Xiao-Wei

    2016-06-01

    amphipod Hyalella azteca. However, low TU values were found for the samples from rural areas. These results indicate that the bottom sediments were exposed to high risk largely by the residual SPs from urban areas. The summed TUs were mostly attributable to cypermethrin, followed by λ-cyhalothrin and es/fenvalerate. Despite permethrin contributing ∼28.7 % of the Σ12SP concentration, it only represented 6.34 % of the summed TUs. Therefore, our results suggest that high levels of urbanization can increase the accumulation of SPs in aquatic environments.

  13. Ecotoxicological assessment of sediments from Tiete river between Salesopolis and Suzano, SP (Brazil); Avaliacao ecotoxicologica de sedimentos do rio Tiete, entre os municipios de Salesopolis e Suzano, SP

    Energy Technology Data Exchange (ETDEWEB)

    Alegre, Gabriel Fonseca

    2009-07-01

    Once introduced into the aquatic environment, many substances can bind or be adsorbed by organic particles in suspension. Depending on the river morphology and hydrological conditions, these particles in suspension containing the contaminants can be deposited along its course, becoming part of the bottom sediments, making them actual sinks and often a source of contamination for the water column and benthic organisms. In the assessment of water, sediment has been one of the most important indicators of the contamination levels in aquatic ecosystems, representing the deposition of contaminants in the environment that occurred over the years and even decades. The Tiete River cross the Sao Paulo state, however, in the metropolitan region of Sao Paulo, the river shows the most severe degradation. In the region of Salesopolis, the waters of the Tiete River are used for public supply, but across the city of Mogi das Cruzes the water quality decreases significantly. Considering the importance of the Tiete river and the sediment for the aquatic biota, this study aimed to evaluate the toxicity of the sediment at five points along the Tiete river, between the cities of Salesopolis and Suzano, Sao Paulo. Four sampling were carried out: two in the summer (rainy season) and two in winter (dry season). The whole sediment was assessed by acute and chronic toxicity tests with Hyalella azteca and Ceriodaphnia dubia, respectively, the elutriate was assessed by chronic toxicity test using C. dubia, while the porewater was evaluated by acute toxicity test with Vibrio fischeri. Samples of river water were also evaluated for chronic toxicity tests with C. dubia. The quantification of metals and hydrocarbons in sediment samples was also carried out in order to correlate the biological effects with the chemical contamination. The obtained results with the whole sediment test indicate Mogi das Cruzes and Suzano cities as the most toxic sites and also as the sites with the highest

  14. Ecotoxicological assessment of sediments from Tiete river between Salesopolis and Suzano, SP (Brazil)

    International Nuclear Information System (INIS)

    Alegre, Gabriel Fonseca

    2009-01-01

    Once introduced into the aquatic environment, many substances can bind or be adsorbed by organic particles in suspension. Depending on the river morphology and hydrological conditions, these particles in suspension containing the contaminants can be deposited along its course, becoming part of the bottom sediments, making them actual sinks and often a source of contamination for the water column and benthic organisms. In the assessment of water, sediment has been one of the most important indicators of the contamination levels in aquatic ecosystems, representing the deposition of contaminants in the environment that occurred over the years and even decades. The Tiete River cross the Sao Paulo state, however, in the metropolitan region of Sao Paulo, the river shows the most severe degradation. In the region of Salesopolis, the waters of the Tiete River are used for public supply, but across the city of Mogi das Cruzes the water quality decreases significantly. Considering the importance of the Tiete river and the sediment for the aquatic biota, this study aimed to evaluate the toxicity of the sediment at five points along the Tiete river, between the cities of Salesopolis and Suzano, Sao Paulo. Four sampling were carried out: two in the summer (rainy season) and two in winter (dry season). The whole sediment was assessed by acute and chronic toxicity tests with Hyalella azteca and Ceriodaphnia dubia, respectively, the elutriate was assessed by chronic toxicity test using C. dubia, while the porewater was evaluated by acute toxicity test with Vibrio fischeri. Samples of river water were also evaluated for chronic toxicity tests with C. dubia. The quantification of metals and hydrocarbons in sediment samples was also carried out in order to correlate the biological effects with the chemical contamination. The obtained results with the whole sediment test indicate Mogi das Cruzes and Suzano cities as the most toxic sites and also as the sites with the highest

  15. Comparative toxicity of sodium carbonate peroxyhydrate to freshwater organisms.

    Science.gov (United States)

    Geer, Tyler D; Kinley, Ciera M; Iwinski, Kyla J; Calomeni, Alyssa J; Rodgers, John H

    2016-10-01

    Sodium carbonate peroxyhydrate (SCP) is a granular algaecide containing H2O2 as an active ingredient to control growth of noxious algae. Measurements of sensitivities of target and non-target species to hydrogen peroxide are necessary for water resource managers to make informed decisions and minimize risks for non-target species when treating noxious algae. The objective of this study was to measure and compare responses among a target noxious alga (cyanobacterium Microcystis aeruginosa) and non-target organisms including a eukaryotic alga (chlorophyte Pseudokirchneriella subcapitata), microcrustacean (Ceriodaphnia dubia), benthic amphipod (Hyalella azteca), and fathead minnow (Pimephales promelas) to exposures of hydrogen peroxide as SCP. Hydrogen peroxide exposures were confirmed using the I3(-) method. SCP margins of safety for these organisms were compared with published toxicity data to provide context for other commonly used algaecides and herbicides (e.g. copper formulations, endothall, and diquat dibromide). Algal responses (cell density and chlorophyll a concentrations) and animal mortality were measured after 96h aqueous exposures to SCP in laboratory-formulated water to estimate EC50 and LC50 values, as well as potency slopes. Despite a shorter test duration, M. aeruginosa was more sensitive to hydrogen peroxide as SCP (96h EC50:0.9-1.0mgL(-)(1) H2O2) than the eukaryotic alga P. subcapitata (7-d EC50:5.2-9.2mgL(-1) H2O2), indicating potential for selective control of prokaryotic algae. For the three non-target animals evaluated, measured 96-h LC50 values ranged from 1.0 to 19.7mgL(-1) H2O2. C. dubia was the most sensitive species, and the least sensitive species was P. promelas, which is not likely to be affected by concentrations of hydrogen peroxide as SCP that would be used to control noxious algae (e.g. M. aeruginosa). Based on information from peer-reviewed literature, other algaecides could be similarly selective for cyanobacteria. Of the

  16. Seasonality in meiofaunal distribution on a tropical beach at Balramgari, northeast coast of India

    Digital Repository Service at National Institute of Oceanography (India)

    Chatterji, A; Ansari, Z.A; Mishra, J.K.; Parulekar, A

    in isopods and patchy or contagious in nematodes, turbellaria, amphipoda and cladocera with salinity, pH, chlorophyll-a and POC respectively. Mean grain size of the sediment was highly correlated with the abundance of cladocerans and harpacticods...

  17. Description of Pseudingolfiella possessionis n. sp. (Crustacea, Amphipoda) from sub-Antarctic Île de La Possession, Crozet archipelago: the second freshwater amphipod known from the Antarctic biome, a human introduction of Gondwanan ancestry?

    Science.gov (United States)

    Smet, Willem H De

    2015-03-31

    A new species of freshwater amphipod, Pseudingolfiella possessionis n. sp. (Senticaudata, Pseudingolfiellidae), is described from the submerged moss vegetation of small brooklets at sub-Antarctic Île de La Possession, Crozet archipelago. It constitutes the second freshwater amphipod species known for the sub-Antarctic and Antarctic region, and the fourth member of the genus. The main characters distinguishing it from all congeners are: the spine on the posterior margin of the dactylus, incisor and lamina mobilis of mandible each with 5 teeth, the setation of the maxilliped, the vestigial second article of pleopod 3 in the female, the undulate and laterally notched posterolateral margin of the external ramus of uropods 1 and 2 in the male, the spinulate dorsomedian projection of the telson.

  18. Mexorchestia: a new genus of talitrid amphipod (Crustacea, Amphipoda, Talitridae) from the Gulf of Mexico and Caribbean Sea, with the description of a new species and two new subspecies.

    Science.gov (United States)

    Wildish, David J; Lecroy, Sara E

    2014-08-26

    Two species of supralittoral Tethorchestia were reported by Bousfield (1984) to occur on the shores of the Gulf of Mexico and closely adjacent waters: T. antillensis Bousfield, 1984 from Quintana Roo, Mexico and an undescribed species, Tethorchestia sp. B of Bousfield (1984), from Florida and the U.S. Gulf coast. In this paper, we rediagnose and illustrate the former taxon based on material from Goodland Bay, Florida, which represents a range extension for that species. We examined the latter taxon from many locations throughout the Gulf of Mexico using classical morphology, epidermal pigment pattern recognition and allometry, reinforced by molecular markers (mitochondrial cytochrome oxidase I, Radulovici 2012), determining that Tethorchestia sp. B represents a new genus and species, comprising two subspecies. The nominate subspecies, Mexorchestia carpenteri carpenteri n. gen., sp. and subsp., is described from Tiger Tail Beach, Florida, based on conventional morphological criteria and its distinctive epidermal pigment patterns. The Tiger Tail Beach ecotope of M. c. carpenteri n. gen., sp. and subsp. was distinct from that of other locations examined in Florida and was associated with epidermal pigment pattern polymorphism, absent at other locations. A second subspecies, distinguished by differences in size, number of articles in the flagellum of antenna 2, the number of marginal setae on oostegite 2 of the female and the number of distal dorsolateral robust setae on the telson, was found in samples from Belize and Mexico. This subspecies is described from material collected at Turneffe Island, Belize, as Mexorchestia carpenteri raduloviciae n. gen., sp. and subsp. Like M. c. carpenteri n. gen., sp. and subsp., this taxon is also associated with epidermal pigment pattern polymorphism. A key is provided for the three currently described species of Tethorchestia (two extant) and two new subspecies of Mexorchestia n.gen. 

  19. Trophic preference and preliminary indication of phylloplane fungal influence on the diet of the non-native Gammarus roeselii Gervais 1835 (Amphipoda, Gammaridae in the sub-lacustrine Ticino river basin (Lombardy, Northern Italy

    Directory of Open Access Journals (Sweden)

    Daniele Paganelli

    2017-03-01

    Full Text Available Gammarids are one of the most successful invaders in freshwater ecosystems due to both their diet plasticity and high reproductive capacity. One such amphipod, Gammarus roeselii, has recently colonised the southern part of the sub-lacustrine Ticino River basin (Northern Italy, where its ecological niche overlaps with the native species Echinogammarus stammeri. In the present paper the food preferences of G. roeselii have been investigated, testing the palatability of different food sources: three macrophytes and three different leaf debris. Moreover, an explorative mycological analysis on the three different leaf debris used in the experiment has been performed. Results of the short-term experiment suggest that aquatic plants are less palatable than allocthonous detritus, probably because they can contain secondary metabolites (i.e. tannins and they have lower nutrient tissues with very high water content. On the contrary, G. roeselii showed a clear preference for the oak leaves, resulted colonized by a more abundant fungal biomass and, therefore, more palatable too.

  20. Review of amphipods of the Melita group (Amphipoda: Melitidae) from the coastal waters of Sakhalin Island (Far East of Russia). II. Genera Quasimelita Jarrett & Bousfield, 1996 and Melitoides Gurjanova, 1934.

    Science.gov (United States)

    Labay, Vjacheslav S

    2014-10-01

    Based on new material, three new species of the genus Quasimelita are described: Q. tolyza sp. nov., Q. jarettii sp. nov. and Q. serraticoxae sp. nov. from northern shelf of Sakhalin Island and contiguous area. The new species of the genus Melitoides, M. kawaii sp. nov. is described from north-east shelf of Sakhalin Island. Keys to the world species of genera Quasimelita and Melitoides are provided. Cladistic analysis of morphological relationships within genera Quasimelita and Melitoides are implemented.

  1. Aquatic assessment of the Pike Hill Copper Mine Superfund site, Corinth, Vermont

    Science.gov (United States)

    Piatak, Nadine M.; Argue, Denise M.; Seal, Robert R.; Kiah, Richard G.; Besser, John M.; Coles, James F.; Hammarstrom, Jane M.; Levitan, Denise M.; Deacon, Jeffrey R.; Ingersoll, Christopher G.

    2013-01-01

    -based criteria are commonly lower values than the hardness-based criteria and thus suggest a greater degree or magnitude of impairment at the sampling locations. The riffle-habitat benthic invertebrate richness and abundance data correlate strongly with the extent of impact based on water quality for both brooks. Similarly, the fish community assessments document degraded conditions throughout most of Pike Hill Brook, whereas the data for the tributary to Cookville Brook suggest less degradation to this brook. The sediment environment shows similar extents of impairment to the surface-water environment, with most sampling locations in Pike Hill Brook, including the wetland areas, and the tributary to Cookville Brook affected. Sediment impairment is caused by elevated copper concentrations, although localized degradation due to elevated cadmium and zinc concentrations was documented on the basis of exceedances of probable effects concentrations (PECs). In contrast to impairment determined by exceedances of PECs, equilibrium-partitioning sediment benchmarks (based on simultaneously extracted metals, acid volatile sulfides, and total organic carbon) predict no toxic effects in sediments at the background locations and uncertain toxic effects throughout Pike Hill Brook and the tributary to Cookville Brook, with the exception of the most downstream Cookville Brook location, which indicated no toxic effects. Acute laboratory toxicity testing using the amphipod Hyalella azteca and the midge Chironomus dilutus on pore waters extracted from sediment in situ indicate impairment (based on tests with H. azteca) at only one location in Pike Hill Brook and no impairment in the tributary to Cookville Brook. Chronic laboratory sediment toxicity testing using H. azteca and C. dilutus indicated toxicity in Pike Hill Brook at several locations in the lower reach and two locations in the tributary to Cookville Brook. Toxicity was not indicated for either species in sediment from the most acidic

  2. Modul.LES: a multi-compartment, multi-organism aquatic life support system as experimental platform for research in ∆g

    Science.gov (United States)

    Hilbig, Reinhard; Anken, Ralf; Grimm, Dennis

    nitrogene-cycle (concentration of ammonium, nitrite and nitrate) as well as conductivity will be measured. For this long term mission an external food supply as has been used with OmegaHab is not sufficient and, therefore, in OmegaHab-XP a nutrition compartment has been added. OmegaHab-XP is a multi-trophic system, designed as a basic concept and test-bed for future multi-modular platform Modul.LES. OmegaHab-XP comprises four different trophic lev-els. The algae experimental container is used as CO2 / O2 exchanger and serves as oxygen source for all heterotrophic organisms. The fish compartment is divided into two areas -namely a hatchery (larval cichlid fish Oreochromis mossambicus) and a fish tank (subadult cichlids). Once the yolk sack is resorbed (stage 19) the juvenile fish are capable to leave the hatchery via escapements into the fish compartment. In order to enable the development of fish from larval yolk sack stages to subadult fish a nutrition compartment is enclosed: In this nutrition compartment the crustacean Hyalella azteca will reproduce and build up a stable population by feeding on the Rigid Hornwort (Ceratophyllum demersum). Younger crustaceans can cross the barrier to the fish tank and can serve as nutrition for fully developed subadult fish. Waste products of all organisms will be assimilated by the water snail Biomphalaria glabrata. The scientific concept of Modul.LES is to establish a multidisciplinary framework of scientists and areas of scientific research (biophysics, molecular-organismic biology, biochemistry etc.) to analyze impacts of g on plants and animals.

  3. Evaluation of Metal Toxicity in Streams Affected by Abandoned Mine Lands, Upper Animas River Watershed, Colorado

    Science.gov (United States)

    Besser, John M.; Allert, Ann L.; Hardesty, Douglas K.; Ingersoll, Christopher G.; May, Thomas W.; Wang, Ning; Leib, Kenneth J.

    2001-01-01

    water; (3) to develop site-specific thresholds for toxicity of Zn and Cu in stream water; and (4) to develop models of the contributions of Cu and Zn to toxicity of stream water, which may be used to characterize toxicity before and after planned remediation efforts. We evaluated the toxicity of metal-contaminated sediments by conducting sediment toxicity tests with two species of benthic invertebrates, the midge, Chironomus tentans. and the amphipod, Hyalella azteca. Laboratory toxicity tests with both taxa, exposed to fine stream-bed sediments collected in September 1997, showed some evidence of sediment toxicity, as survival of midge larvae in sediments from Cement Creek (C48) and lower Mineral Creek (M34), and growth of amphipods in sediments from these sites and three Animas River sites (A68, Animas at Silverton; A72, Animas below Silverton, and A73, Animas at Elk Park) were significantly reduced compared to a reference site, South Mineral Creek (SMC) . Amphipods were also exposed to site water and fine stream-bed sediment, separately and in combination, during the late summer low flow period (August-September) of 1998. In these studies, stream water, with no sediment present, from all five sites tested (same sites as above, except C48) caused 90% to 100% mortality of amphipods. In contrast, significant reductions in survival of amphipods occurred at two sites (A72 and SMC) in exposures with field-collected sediment plus stream water, and at only one site (A72) in exposures with sediments and clean overlying water. Concentrations of Zn, Pb, Cu, and Cd were high in both sediment and pore water (interstitial water) from most sites tested, but greatest sediment toxicity was apparently associated with greater concentrations of Fe and/or Al in sediments. These results suggest that fine stream-bed sediments of the more contaminated stream reaches of the upper Animas River watershed are toxic to benthic invertebrates, but that these impacts are less serious than tox

  4. Toxicity of chromium (VI) to two mussels and an amphipod in water-only exposures with or without a co-stressor of elevated temperature, zinc, or nitrate

    Science.gov (United States)

    Wang, Ning; Kunz, James L.; Ivey, Chris D.; Ingersoll, Christopher G.; Barnhart, M. Christopher; Glidewell, Elizabeth A.

    2017-01-01

    The objectives of the present study were to develop methods for propagating western pearlshell (Margaritifera falcata) for laboratory toxicity testing and evaluate acute and chronic toxicity of chromium VI [Cr(VI)] to the pearlshell and a commonly tested mussel (fatmucket, Lampsilis siliquoidea at 20 °C or in association with a co-stressor of elevated temperature (27 °C), zinc (50 µg Zn/L), or nitrate (35 mg NO3/L). A commonly tested invertebrate (amphipod, Hyalella azteca) also was tested in chronic exposures. Newly transformed pearlshell (~1 week old) were successfully cultured and tested in acute 96 h Cr exposures (control survival 100%). However, the grow-out of juveniles in culture for chronic toxicity testing was less successful and chronic 28-day Cr toxicity tests started with 4 month-old pearlshell failed due to low control survival (39–68%). Acute median effect concentration (EC50) for the pearlshell (919 µg Cr/L) and fatmucket (456 µg Cr/L) tested at 20 °C without a co-stressor decreased by a factor of > 2 at elevated temperature but did not decrease at elevated Zn or elevated NO3. Chronic 28-day Cr tests were completed successfully with the fatmucket and amphipod (control survival 83–98%). Chronic maximum acceptable toxicant concentration (MATC) for fatmucket at 20 °C (26 µg Cr/L) decreased by a factor of 2 at elevated temperature or NO3 but did not decrease at elevated Zn. However, chronic MATC for amphipod at 20 °C (13 µg Cr/L) did not decrease at elevated temperature, Zn, or NO3. Acute EC50s for both mussels tested with or without a co-stressor were above the final acute value used to derive United States Environmental Protection Agency acute water quality criterion (WQC) for Cr(VI); however, chronic MATCs for fatmucket at elevated temperature or NO3 and chronic MATCs for the amphipod at 20 °C with or without elevated Zn or NO3 were about equal to the chronic WQC. The results indicate that (1) the elevated temperature

  5. Laboratory toxicity and benthic invertebrate field colonization of Upper Columbia River sediments: finding adverse effects using multiple lines of evidence.

    Science.gov (United States)

    Fairchild, J F; Kemble, N E; Allert, A L; Brumbaugh, W G; Ingersoll, C G; Dowling, B; Gruenenfelder, C; Roland, J L

    2012-07-01

    From 1930 to 1995, the Upper Columbia River (UCR) of northeast Washington State received approximately 12 million metric tons of smelter slag and associated effluents from a large smelter facility located in Trail, British Columbia, approximately 10 km north of the United States-Canadian border. Studies conducted during the past two decades have demonstrated the presence of toxic concentrations of heavy metals in slag-based sandy sediments, including cadmium, copper, zinc, and lead in the UCR area as well as the downstream reservoir portion of Lake Roosevelt. We conducted standardized whole-sediment toxicity tests with the amphipod Hyalella azteca (28-day) and the midge Chironomus dilutus (10-day) on 11 samples, including both UCR and study-specific reference sediments. Metal concentrations in sediments were modeled for potential toxicity using three approaches: (1) probable effects quotients (PEQs) based on total recoverable metals (TRMs) and simultaneously extracted metals (SEMs); (2) SEMs corrected for acid-volatile sulfides (AVS; i.e., ∑SEM - AVS); and (3) ∑SEM - AVS normalized to the fractional organic carbon (f(oc)) (i.e., ∑SEM - AVS/f(oc)). The most highly metal-contaminated sample (∑PEQ(TRM) = 132; ∑PEQ(SEM) = 54; ∑SEM - AVS = 323; and ∑SEM - AVS/(foc) = 64,600 umol/g) from the UCR was dominated by weathered slag sediment particles and resulted in 80% mortality and 94% decrease in biomass of amphipods; in addition, this sample significantly decreased growth of midge by 10%. The traditional ∑AVS - SEM, uncorrected for organic carbon, was the most accurate approach for estimating the effects of metals in the UCR. Treatment of the toxic slag sediment with 20% Resinex SIR-300 metal-chelating resin significantly decreased the toxicity of the sample. Samples ∑SEM - AVS > 244 was not toxic to amphipods or midge in laboratory testing, indicating that this value may be an approximate threshold for effects in the UCR. In situ benthic invertebrate

  6. Non-target trials with Pseudomonas fluorescens strain CL145A, a lethal control agent of dreissenid mussels (Bivalvia: Dreissenidae

    Directory of Open Access Journals (Sweden)

    Daniel P. Molloy

    2013-01-01

    Full Text Available In an effort to develop an efficacious and environmentally safe method for managing zebra mussels (Dreissena polymorpha and quaggamussels (Dreissena rostriformis bugensis, we initiated a research project investigating the potential use of bacteria and their naturalmetabolic products as biocontrol agents. This project resulted in the discovery of an environmental isolate lethal to dreissenid mussels,Pseudomonas fluorescens strain CL145A (Pf-CL145A. In previous published reports we have demonstrated that: 1 Pf-CL145A’s mode ofaction is intoxication (not infection; 2 natural product within ingested bacterial cells lyse digestive tract epithelial cells leading to dreisseniddeath; and 3 high dreissenid kill rates (>90% are achievable following treatment with Pf-CL145A cells, irrespective of whether thebacterial cells are dead or alive. Investigating the environmental safety of Pf-CL145A was also a key element in our research efforts, andherein, we report the results of non-target trials demonstrating Pf-CL145A’s high specificity to dreissenids. These acute toxicity trials weretypically single-dose, short-term (24-72 h exposures to Pf-CL145A cells under aerated conditions at concentrations highly lethal todreissenids (100 or 200 mg/L. These trials produced no evidence of mortality among the ciliate Colpidium colpoda, the cladoceran Daphniamagna, three fish species (Pimephales promelas, Salmo trutta, and Lepomis macrochirus, and seven bivalve species (Mytilus edulis,Pyganodon grandis, Pyganodon cataracta, Lasmigona compressa, Strophitus undulatus, Lampsilis radiata, and Elliptio complanata. Lowmortality (3-27% was recorded in the amphipod Hyalella azteca, but additional trials suggested that most, if not all, of the mortality couldbe attributed to some other unidentified factor (e.g., possibly particle load or a water quality issue rather than Pf-CL145A’s dreissenidkillingnatural product. In terms of potential environmental safety, the results of

  7. Trace element, semivolatile organic, and chlorinated organic compound concentrations in bed sediments of selected streams at Fort Gordon, Georgia, February-April 2010

    Science.gov (United States)

    Thomas, Lashun K.; Journey, Celeste A.; Stringfield, Whitney J.; Clark, Jimmy M.; Bradley, Paul M.; Wellborn, John B.; Ratliff, Hagan; Abrahamsen, Thomas A.

    2011-01-01

    sediment samples from most nonreference sites exceeded concentrations in samples from reference sites at Fort Gordon. Bed sediments from one of the nonreference sites sampled contained the highest concentrations of copper and lead with elevated levels of zinc and chromium relative to reference sites. The percentage change of major ions, trace elements, and total organic carbon that had been detected at sites previously sampled in May 1998 and current bed sediment sites ranged from -4 to 8 percent with an average percentage change of less than 1 percent. Concentrations of major ions and trace elements in bed sediments exceeded probable effect levels for aquatic life (based on the amphipod Hyalella azteca) established by the U.S. Environmental Protection Agency at 46 and 69 percent of the current and previously sampled locations, respectively. The greatest frequency of exceedances for major ions and trace elements in bed sediments was observed for lead. Concentrations of semivolatile organic compounds, organochlorine pesticides, and polychlorinated biphenyls were detected in bed sediment samples at 94 percent of the sites currently sampled. Detections of these organic compounds were reported with greater frequency in bed sediments at upstream sampling locations, when compared to downstream locations. The greatest number of detections of these compounds was reported for bed sediment samples collected from two creeks above a lake. The percentage change of semivolatile organic compounds detected at previously sampled and current bed sediment sites ranged from -68 to 100 percent with the greatest percentage increase reported for one of the creeks above the lake. Concentrations of semivolatile organic compounds and polychlorinated biphenyls in bed sediments exceeded aquatic life criteria established by the U.S. Environmental Protection Agency at three sites. Contaminant compounds exceeding aquatic life criteria included fluoranthene, phenanthrene, anthracene, benzo(a)anthracene

  8. Drugs + HIV, Learn the Link

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    Full Text Available ... and unsafe sexual practices. Drug use disorder treatment programs also serve an important role in providing current ... Psychiatry (AACAP) The United Negro College Fund, Special Programs Latino Commission on AIDS Azteca America Foundation/Vive ...

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    Full Text Available ... link between non-injection drug use and HIV. Television Networks: MunDos Azteca America ... and Families The American Academy of Child & Adolescent Psychiatry (AACAP) The United Negro College Fund, ...

  10. Drugs + HIV, Learn the Link

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    Full Text Available ... Adolescent Psychiatry (AACAP) The United Negro College Fund, Special Programs Latino Commission on AIDS Azteca America Foundation/ ... Montgomery College Center for the Advancement of Distance Education University of Southern California, Maternal Child & Adolescent Program ...

  11. Review of the Ecotoxicological Properties of the Methylenedianiline Substances.

    Science.gov (United States)

    Schupp, T; Allmendinger, H; Bossuyt, B T A; Hidding, B; Tury, B; West, R J

    Concerning chronic toxicity, D. magna is the most sensitive species tested against MDA aquatic exposures, with a 21 days-NOEC of 0.00525 mg/L. Exposure of daphnids takes place via the aquatic phase. Other species of the same phylum (Arthropoda) appear to be less sensitive albeit with exposures via soil or sediment, with a 28 days-NOEC of 562 mg/kg d. w. soil (F. candida) and 41.3 mg/kg d. w. sediment (Hyalella azteca), for reproductive and survival endpoints, respectively. Also for acute toxicity, D. magna is more sensitive than the other species, with an 48 h-EC50 that spreads over two orders of magnitude, ranging from 0.019 to 2.7 mg/L. Fish show a more uniform reaction to MDA, with 96 h-LC50 ranging from about 20 to 60 mg/L; chronic data for fish are not available. Acute toxicity data for algae and cyanobacteria are in the range of 1-10 mg/L; based on growth rate, the 72 h-NOEC r or E r C 10 of MDA to algae is 0.3-9.3 mg/L.For sediment organisms, the black worm L. variegatus shows the highest sensitivity against MDA with a NOEC between ≤3.75 mg/kg and 30 mg/kg d. w., followed by the amphipod H. azteca. The lower sensitivity of L. variegatus in the second study compared to the first study is obviously attributable to the different feeding regimes (semi-continuous feeding against pre-spiked sediment). One argument might be that semi-continuous feeding allows the organisms to avoid the contaminated food. However, a change from semi-continuous feeding to sediment pre-spiked with nettle powder (Urtica sp.) results in an earlier and much stronger increase in ammonia concentration in the system. This became apparent after both studies on the blackworm were finalized. The ammonia 96 h-EC50 for the blackworm is 0.69 mg/L at pH = 8.2, and the 96 h-EC10 at pH = 8.2 is 0.33 mg/L (Hickey and Vickers, Arch Environ Contam Toxicol 26:292-298, 1994). As a result, the lower NOEC and LOEC in the second study with L. variegatus are probably attributable

  12. Fauna associada ao fital Halimeda opuntia (Linnaeus Lamouroux (Chlorophyta do Recife da Ponta Verde, Maceió, Alagoas, Brasil Associated fauna of the phytal Halimeda opuntia (Linnaeus Lamouroux (Chlorophyta on Ponta Verde reef in Maceió, Alagoas, Brazil

    Directory of Open Access Journals (Sweden)

    Cardeluzia Guilherme dos Santos

    1995-01-01

    Full Text Available The bell quadrai lecnique were used lo oblain Rve bimestral samples during 1992. Fifteen laxoiioinic groups were found and Amphipoda had numerical dominante, Polychaeta and Decapoda are als

  13. The evolution of intermediate castration virulence and ant coexistence in a spatially structured environment.

    Science.gov (United States)

    Szilágyi, András; Scheuring, István; Edwards, David P; Orivel, Jerome; Yu, Douglas W

    2009-12-01

    Theory suggests that spatial structuring should select for intermediate levels of virulence in parasites, but empirical tests are rare and have never been conducted with castration (sterilizing) parasites. To test this theory in a natural landscape, we construct a spatially explicit model of the symbiosis between the ant-plant Cordia nodosa and its two, protecting ant symbionts, Allomerus and Azteca. Allomerus is also a castration parasite, preventing fruiting to increase colony fecundity. Limiting the dispersal of Allomerus and host plant selects for intermediate castration virulence. Increasing the frequency of the mutualist, Azteca, selects for higher castration virulence in Allomerus, because seeds from Azteca-inhabited plants are a public good that Allomerus exploits. These results are consistent with field observations and, to our knowledge, provide the first empirical evidence supporting the hypothesis that spatial structure can reduce castration virulence and the first such evidence in a natural landscape for either mortality or castration virulence.

  14. Life history and population dynamics of an estuarine amphipod, Eriopisa chilkensis Chilton (Gammaridae)

    Digital Repository Service at National Institute of Oceanography (India)

    Aravind, N.P.; Sheeba, P.; Nair, K.K.C.; Achuthankutty, C.T.

    Life history and Population Dynamics of an Estuarine Amphipod –Eriopisa chilkensis Chilton (Gammaridae) Nisha. P. Aravind, P. Sheeba, K.K.C. Nair and C.T.Achuthankutty* National Institute of Oceanography, Regional Centre, Cochin 682018, India... of laboratory data to the field suggests that E. chilkensis in Cochin estuary has a multivoltine life cycle. Key words: - Eriopisa chilkensis, Amphipoda, life cycle, population dynamics, Cochin estuary, India 2 1. Introduction Life-history traits of 214 amphipod...

  15. An evaluation of invertebrate dynamics in a drinking water distribution system: a South African perspective

    OpenAIRE

    2008-01-01

    M.Sc. The occurrence of invertebrates in drinking water supplies is a common consumer complaint with studies showing that very few drinking water distribution networks are totally free of organisms. A detailed investigation of different types of metazoan animals in the drinking water supply networks of South Africa has not been undertaken. In limited worldwide studies, invertebrates (mainly Amphipoda, Chironomidae, Cladocera, Copepoda and Ostracoda) have been detected in produced drinking ...

  16. Comparing Effects of Lake- and Watershed-Scale Influences on Communities of Aquatic Invertebrates in Shallow Lakes

    Science.gov (United States)

    Hanson, Mark A.; Herwig, Brian R.; Zimmer, Kyle D.; Fieberg, John; Vaughn, Sean R.; Wright, Robert G.; Younk, Jerry A.

    2012-01-01

    Constraints on lake communities are complex and are usually studied by using limited combinations of variables derived from measurements within or adjacent to study waters. While informative, results often provide limited insight about magnitude of simultaneous influences operating at multiple scales, such as lake- vs. watershed-scale. To formulate comparisons of such contrasting influences, we explored factors controlling the abundance of predominant aquatic invertebrates in 75 shallow lakes in western Minnesota, USA. Using robust regression techniques, we modeled relative abundance of Amphipoda, small and large cladocera, Corixidae, aquatic Diptera, and an aggregate taxon that combined Ephemeroptera-Trichoptera-Odonata (ETO) in response to lake- and watershed-scale characteristics. Predictor variables included fish and submerged plant abundance, linear distance to the nearest wetland or lake, watershed size, and proportion of the watershed in agricultural production. Among-lake variability in invertebrate abundance was more often explained by lake-scale predictors than by variables based on watershed characteristics. For example, we identified significant associations between fish presence and community type and abundance of small and large cladocera, Amphipoda, Diptera, and ETO. Abundance of Amphipoda, Diptera, and Corixidae were also positively correlated with submerged plant abundance. We observed no associations between lake-watershed variables and abundance of our invertebrate taxa. Broadly, our results seem to indicate preeminence of lake-level influences on aquatic invertebrates in shallow lakes, but historical land-use legacies may mask important relationships. PMID:22970275

  17. Drugs + HIV, Learn the Link

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    Full Text Available ... HIV/AIDS, and the general public. U.S. National Library of Medicine HIV/AIDS Information : Specialized Information Services. ... Adolescent Psychiatry (AACAP) The United Negro College Fund, Special Programs Latino Commission on AIDS Azteca America Foundation/ ...

  18. A new species of myrmecophilous lady beetle in the genus Diomus (Coleoptera: Coccinellidae: Diomini) from Chiapas, Mexico that feeds on green coffee scale, Coccus viridis (Green) (Hemiptera: Coccidae)

    Science.gov (United States)

    A new species of myrmecophilous lady beetle in the genus Diomus (Coleoptera: Coccinellidae: Diomini) is described from a coffee agroecosystem in Chiapas, Mexico. The new species was found preying on the green coffee scale pest, Coccus viridis (Green), tended primarily by Azteca sericeasur Longino an...

  19. Drugs + HIV, Learn the Link

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    Full Text Available ... public service ads (PSA) where an HIV-positive teenager recounts the night she went to a party ... Youth and Families The American Academy of Child & Adolescent Psychiatry (AACAP) The ... Teen Aids Azteca America Foundation/Vive Sin Drogras AdCouncil ...

  20. Consumption of Mullerian Bodies by Golden-olive Woodpecker (Colaptes rubiginosus) in Nicaragua's Highlands

    Science.gov (United States)

    M.A. Torrez; Wayne Arendt; L. Diaz

    2016-01-01

    The Golden-olive Woodpecker is a generalist species found in a wide range of habitats, being particularly common in coffee plantations within Nicaraguan cloud forests. Observations of an individual feeding at the base of Cecropia leaves revealed it was consuming Mullerian bodies that the Cecropia produces to feed Azteca ants as part of a host-inhabitant mutualistic...

  1. Variações ontogênicas e sazonais na dieta de Etropus crossotus Jordan e Gilbert, 1882 (Paralichthydae na baía de Ubatuba-Enseada, Estado de Santa Catarina, Brasil = Ontogenetic and seasons changes in the diet of Etropus crossotus Jordan and Gilbert, 1882 (Paralichthydae at Ubatuba-Enseada Bay, Santa Catarina State, Brazil

    Directory of Open Access Journals (Sweden)

    Matheus Oliveira Freitas

    2011-04-01

    Full Text Available Foram investigadas as variações ontogênicas e sazonais na dieta de Etropus crossotus coletados na baía de Ubatuba-Enseada, Estado de Santa Catarina, Brasil. Redes de arrasto com porta foram utilizadas para as coletas mensais, e 60 exemplares foram coletados entre outubro de 2003 e setembro de 2004. Maior similaridade entre os Índices de Importância Alimentar foi observada entre a primavera e o outono. Crustáceos decápodes representaram 50% dos itens alimentares durante a primavera e outono, e crustáceos anfípodes foram os itens mais representativos no inverno. Maior similaridade entre os IAifoi observada entre as classes 1, 2 e 4, pela alta representatividade de Decapoda, e entre as classes 5, 6 e 7, em função da representatividade de Decapoda e Amphipoda. Os resultados obtidos foram similares a outros estudos realizados na região costeira Sul do Brasil.Ontogenetic and seasonal changes in the diet of Etropus crossotussampled at Ubatuba-Enseada Bay in Santa Catarina State, Brazil were investigated. A trawl net was used for the surveys, and 60 fish were collected monthly during October (2003 and September (2004. The highest similarity of the Alimentary Importance Index (AII wasobserved between spring and autumn. Crustacea Decapoda represented 50% of the feeding items during spring and fall, and Crustacea Amphipoda were the most representative item in winter. The highest AII similarity was observed among length classes 1, 2 and 4, whichwas related to Decapoda representation, and among length classes 5, 6 and 7, because of Decapoda and Amphipoda importance. Results were similar to other studies in the southern coast of Brazil.

  2. FOOD COMPOSITION OF GRAYLING Thymallus thymallus L., FROM THE RIVER KRUŠNICA

    Directory of Open Access Journals (Sweden)

    Azra Bećiraj Bakrač

    2008-07-01

    Full Text Available Total of 118 specimens of grayling (Thymallus thymallus L. is caught with sport fishing techniques in the river Krušnica. The objectives of this research was to obtain data about the diet composition of these species in natural biotopes. Dominant food of grayling from the river Kru{nica were Amphipoda and Ephemeroptera, while the most abundant number belonging to the group of Diptera. Secondary diet consists of Trichoptera with Hydrop%syche sp. as dominant species, then Gastropoda with Valvata sp., Coleoptera and Formicidae. Grayling occasionally consume Isopoda, Hirudinea, Plecoptera, Oligochaeta, Heteroptera, Aranea, Lepidoptera, Hydracarina and Hymenoptera, as well as plant detritus.

  3. Bio indication of water quality in the Bogota Sabane using fuzzy logic sagging and aquatic micro invertebrates

    International Nuclear Information System (INIS)

    Gutierrez, Juan David; Riss Wolfgang; Ospina Rodolfo

    2002-01-01

    An application of the Sagging-type fuzzy logic to calculate biological water quality in Bogota, Colombia is presented 28 sites corresponding to 9 watersheds in the Bogota area were used. The organisms selected were: Leptoceridae and Hidrobiosidae as indicators of clean waters, Planariidae and Amphipoda as indicators of polluted waters and Psychodida and Syrphidae as indicators of highly polluted waters Chironomids were also included. In order to prove the degree of reliability of Sugeno-type fuzzy logic, the results obtained were compared with values for the Cfq index, and a highly significant correlation was obtained

  4. Los Cuícatl de Acomiztli Netzahualcóyotl: entre el ritual y la estética del pueblo Nahual

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    Carlos Daniel Ortiz Caraballo

    2016-01-01

    Full Text Available Este artículo muestra el aspecto literario de uno de las culturas más desarrolladas del México antiguo: el pueblo azteca - náhuatl. Para este caso, se consideran los Cuícatl de Acomiztli (1402-1469. Su objetivo es develar los temas que sustentan la lírica de este príncipe de la cultura azteca - náhuatl. Para ello, se ha considerado una interpretación de los escritos desde la antropología literaria, que entiende el texto como fragmento de una cultura, por lo que el centro del análisis lo constituye el sujeto creador y su interacción con el entorno. De esa forma, se parte de conceptos, tales como: cultura náhuatl, cuícatl y visión de mundo religiosa, entre otros. Con ello, se busca exteriorizar, tanto el mensaje de libertad y esperanza que plasmó el cuicapicqui (forjador de cantos prehispánico en sus Cuícatl, como la contribución del pueblo azteca náhuatl a las letras latinoamericanas.

  5. Ant species confer different partner benefits on two neotropical myrmecophytes.

    Science.gov (United States)

    Frederickson, Megan E

    2005-04-01

    The dynamics of mutualistic interactions involving more than a single pair of species depend on the relative costs and benefits of interaction among alternative partners. The neotropical myrmecophytes Cordia nodosa and Duroia hirsuta associate with several species of obligately symbiotic ants. I compared the ant partners of Cordia and Duroia with respect to two benefits known to be important in ant-myrmecophyte interactions: protection against herbivores provided by ants, and protection against encroaching vegetation provided by ants. Azteca spp., Myrmelachista schumanni, and Allomerus octoarticulatus demerarae ants all provide the leaves of Cordia and Duroia some protection against herbivores. However, Azteca and Allomerus provide more protection than does Myrmelachista to the leaves of their host plants. Although Allomerus protects the leaves of its hosts, plants occupied by Allomerus suffer more attacks by herbivores to their stems than do plants occupied by other ants. Relative to Azteca or Allomerus, Myrmelachista ants provide better protection against encroaching vegetation, increasing canopy openness over their host plants. These differences in benefits among the ant partners of Cordia and Duroia are reflected in the effect of each ant species on host plant size, growth rate, and reproduction. The results of this study show how mutualistic ant partners can differ with respect to both the magnitude and type of benefits they provide to the same species of myrmecophytic host.

  6. Hydrobiological study of the small stream on the Czech–Moravian Highlands

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    Ivo Sukop

    2010-01-01

    Full Text Available Zoobenthos of the Fryšávka Rivulet was investigated in the years 2007–2008. Research included also physico-chemical factors of water (temperature, pH, conductivity, oxygen saturation. Altogether, 144 taxa of zoobenthos were determined in the Fryšávka Rivulet: Coelenterata (1 taxon, Turbellaria (1 taxon, Oligochaeta (6 taxa, Hirudinea (1 taxon, Mollusca (5 taxa, Amphipoda (1 taxon, Decapoda (1 taxon, Acari (1 taxon, Ephemeroptera (18 taxa, Plecoptera (18 taxa, Heteroptera (1 taxon, Megaloptera (1 taxon, Planipennia (1 taxon, Trichoptera (36 taxa, Coleoptera (8 taxa, Diptera (44 taxa. Altogether, 76 taxa of zoobenthos were determined in Medlovka brook: Coelenterata (1 taxon, Turbellaria (1 taxon, Oligochaeta (2 taxa, Mollusca (1 taxon, Isopoda (1 taxon, Amphipoda (1 taxon, Acari (1 taxon, Ephemeroptera (14 taxa, Plecoptera (8 taxa, Megaloptera (1 taxon, Trichoptera (17 taxa, Coleoptera (6 taxa, Diptera (22 taxa.The average abundance of zoobenthos of the Fryšávka Rivulet was 3208 ind.m−2, the average biomass was 7.5 g . m−2, respectively. The same values for the Medlovka brook were: abundance 3238 ind.m−2 and biomass 5.8 g . m−2. The average value of the saprobic index for the whole Fryšávka Rivulet was 1.25 (oligosaprobity, for the Medlovka brook 1.42 (oligosaprobity.

  7. Alterations in the energy budget of Arctic benthic species exposed to oil-related compounds

    Energy Technology Data Exchange (ETDEWEB)

    Olsen, Gro Harlaug [Akvaplan-niva, Polar Environmental Center, N-9296 Tromso (Norway) and Norwegian College of Fishery Science, University of Tromso, N-9037 Tromso (Norway)]. E-mail: gho@akvaplan.niva.noph; Sva, Eirin [Akvaplan-niva, Polar Environmental Center, N-9296 Tromso (Norway); Carroll, JoLynn [Akvaplan-niva, Polar Environmental Center, N-9296 Tromso (Norway); Camus, Lionel [Akvaplan-niva, Polar Environmental Center, N-9296 Tromso (Norway); De Coen, Wim [Laboratory for Ecophysiology, Biochemistry and Toxicology, University of Antwerp (UA), Groenenborgerlaan 171, B-2020 Antwerp (Belgium); Smolders, Roel [Laboratory for Ecophysiology, Biochemistry and Toxicology, University of Antwerp (UA), Groenenborgerlaan 171, B-2020 Antwerp (Belgium); Environmental Toxicology, VITO, Boeretang 200, B-2400 Mol (Belgium); Overaas, Helene [Norwegian Institute for Water Research (NIVA), CIENS, Gaustadalleen, N-0316 Oslo (Norway); Multiconsult AS, Hoffsveien 1, N-0275 Oslo (Norway); Hylland, Ketil [Norwegian Institute for Water Research (NIVA), CIENS, Gaustadalleen, N-0316 Oslo (Norway); Department of Biology, University of Oslo, P.O. Box 1066, Blindern, N-0316 Oslo (Norway)

    2007-06-15

    We studied cellular energy allocation (CEA) in three Arctic benthic species (Gammarus setosus (Amphipoda), Onisimus litoralis (Amphipoda), and Liocyma fluctuosa (Bivalvia)) exposed to oil-related compounds. The CEA biomarker measures the energy budget of organisms by biochemically assessing changes in energy available (carbohydrates, protein and lipid content) and the integrated energy consumption (electron transport system activity (ETS) as the cellular aspect of respiration). Energy budget was measured in organisms subjected to water-accommodated fraction (WAF) of crude oil and drill cuttings (DC) to evaluate whether these compounds affect the energy metabolism of the test species. We observed significantly lower CEA values and higher ETS activity in G. setosus subjected to WAF treatment compared to controls (p {<=} 0.03). Higher CEA value and lower cellular respiration were observed in O. litoralis exposed to DC compared to controls (p = 0.02). No difference in the energy budget of L. fluctuosa was observed between the treatments (p {>=} 0.19). Different responses to oil-related compounds between the three test species are likely the result of differences in feeding and burrowing behavior and species-specific sensitivity to petroleum-related compounds.

  8. Trophic niche overlap between flatfishes in a nursery area on the Portuguese coast

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    Henrique N. Cabral

    2002-09-01

    Full Text Available The diets and the trophic niche overlap between seven flatfish species were studied in a coastal nursery adjoining to the Tagus estuary (Portugal. Fish were sampled monthly, from March to November 1999, using a beach seine. Arnoglossus imperialis (Rafinesque, 1810, Arnoglossus laterna (Walbaum, 1792 and Arnoglossus thori Kyle, 1913, fed mainly on crustaceans. The diets of Buglossidium luteum (Risso, 1810 and Dicologoglossa cuneata (Moreau, 1881 were mainly composed of Bivalvia and Polychaeta, while for Scophthalmus rhombus (Linnaeus, 1758 the main food items were Mysidacea and Teleostei. The diet of Pegusa lascaris (Risso, 1810 was mainly composed by Cumacea, Bivalvia, Decapoda and Amphipoda. Based on diet similarities two main groups were identified: one composed of A. imperialis, A. laterna, A. thori and S. rhombus, and the other grouping B. luteum, P. lascaris and D. cuneata. For the most common flatfishes, a similar pattern of diet seasonal variation was found, such that Amphipoda presented higher indices values in the period from March to June, while from July to November, Decapoda were more abundant. Although high values of diet overlap were obtained among some of the species, the main items in the diet of flatfishes are probably the most abundant prey in this coastal area, which suggests a generalist and opportunistic utilization of these food resources. Furthermore, niche overlap between these species is probably minimized by differences in resource use in other niche dimensions, namely time and space.

  9. The Impact of Geomorphology and Human Disturbances on the Faunal Distributions in Tiquara and Angico Caves of Campo Formoso, Bahia, Brazil

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    André Vieira de Araujo

    2015-04-01

    Full Text Available Characterization of fauna is important for the understanding of communities and ecosystems, enabling the design of actions for conservation. In the present piece of work, we identified total 45 morphospecies belonging to the order Acarina, Pseudoscorpionida, Dictyoptera, Araneida, Amblypygi, Isopoda, Plecoptera, Amphipoda, Zygentoma, Spirostreptida, Coleoptera, Collembola, Diptera, Ensifera, Heteroptera, Hymenoptera, Lepidoptera and Psocoptera from two distinct types of caves of Campo Formoso, state of Bahia in Brazil. It was made to provide subsidies for conservation studies. The targeted caves were Tiquara Cave suffered for many years from saltpeter extraction and Angico Cave less visited cave having high tourist potential. Though the conservation status is much better in Angico cave, but we found comparatively more morphospecies in Tiquara cave.

  10. STUDY UPON THE MACROZOOBENTHIC COMMUNITIES FROM THE DANUBE RIVER BY BAZIAŞ-PORŢILE DE FIER SECTOR (SOUTH-WESTERN ROMANIA

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    ADINA-MIRELA PANĂ

    2009-01-01

    Full Text Available Different sensitivity of benthic macroinvertebrates was used in determining water quality of the eight major tributaries of the Danube, which drains two mountain ranges: Locvei and Almăjului, within the context in which the macrozoobenthic community is influenced by changes in the qualitative parameters of aquatic ecosystems. To get an overview, a series of physical- chemical parameters (water temperature, pH, oxygen, conductivity, cyanide, nitrites, nitrates, phosphates was studied in parallel with the study of benthic community. Elevated abundance of benthic groups in the case of water quality characteristic (Ephemeroptera, Trichoptera, Plecoptera, Amphipoda, along with their high frequency in all the monitored tributaries in the present study and the water quality parameters maintained within normal limits fits these lotic ecosystems in the A class of surface water quality.

  11. BENTHIC MACROINVERTEBRATE COMMUNITY STRUCTURE IN THE UPPER HYDROGRAPHIC BASIN OF CERNA RIVER IN RELATION TO WATER QUALITY (WEST AND SOUTH-WESTERN ROMANIA

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    CORINA TUDORESCU

    2009-01-01

    Full Text Available The quality of an hydrographic basin may be reflected by the composition of benthic macroinvertebrates communities as they can be influenced by the quality degradations of physical and chemical water parameters. The structure of the benthic community in the upper basin of the Cerna river was characterized by the presence of 13 groups. Abundance and frequency values recorded for benthic communities varied according to the physical-chemical conditions specific to each sample collecting station. Plecoptera, Ephemeroptera, Trichoptera and Amphipoda were influenced by changes in water quality, changes that were reflected in the composition and structure of such communities with low levels of abundance, reaching extinction in some areas of the basin.

  12. Biodiversity of macrozoobenthos some running waters of southern Moravia

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    Ivo Sukop

    2010-01-01

    Full Text Available The present work gives the results of the research of macrozoobenthos some running waters drai­na­ge areas of the Dyje River (southern Moravia – Czech Republic. Altogether, 762 taxa of macrozoobenthos were determined from the running waters of southern Moravia. Porifera (3, Hydrozoa (3, Turbellaria (8, Nematoda (14, Nematomorpha (1, Oligochaeta (60, Hirudinea (18, Bryozoa (5, Mollusca (44, Isopoda (2, Amphipoda (4, Decapoda (2, Hydracarina (17, Ephemeroptera (65, Plecoptera (55, Odonata (26, Heteroptera (3, Plannipennia (2, Trichoptera (128, Coleoptera (59, Diptera (243. Some taxa of macrozoobenthos are extinct unfortunately in running waters of Southern Moravia at present time. Another ones appear newly, for example snail Potamopyrgus antipodarum from New Zealand or Dreissena polymorpha from Pontic region. The data presented in this paper may serve as a basis for future monitoring of water quality and zoobenthos composition in connection with presumption of climate changes.

  13. The effects of the Sea Empress oil spill on the sub-tidal macrobenthos of the Milford Haven waterway: a comparison of survey data from October 1993 and October 1996. V. 1

    International Nuclear Information System (INIS)

    Hobbs, G.; Smith, J.; Law, R.J.

    1997-12-01

    This report presents the results of the October 1996 Milford Haven Macrobenthic survey which was conducted eight months after the Sea Empress oil spill, and provides a comparison with the macrobenthic survey of three years previously. The primary aim of this study was to assess the effect of the Sea Empress oil spill upon the benthic macrofauna of the Milford Haven Waterway. In order that direct comparison with the 1993 study could be made wherever possible, there has been consistency in the timing and methodologies employed in the field and in the laboratory. Comparison of individual species distributions and densities indicate changes in several species that can be ascribed to minor positional differences in sample location and to natural variability. However, some taxa, notably amongst the Amphipoda, show widespread declines in their distribution and densities. The balance of evidence suggests that these changes are an acute response to the oil spill. (author)

  14. The effects of the Sea Empress oil spill on the sub-tidal macrobenthos of the Milford Haven waterway: a comparison of survey data from October 1993 and October 1996. V. 2

    International Nuclear Information System (INIS)

    Hobbs, G.; Smith, J.; Law, R.J.

    1997-12-01

    This report presents the results of the October 1996 Milford Haven Macrobenthic survey which was conducted eight months after the Sea Empress oil spill, and provides a comparison with the macrobenthic survey of three years previously. The primary aim of this study was to assess the effect of the Sea Empress oil spill upon the benthic macrofauna of the Milford Haven Waterway. In order that direct comparison with the 1993 study could be made wherever possible, there has been consistency in the timing and methodologies employed in the field and in the laboratory. Comparison of individual species distributions and densities indicate changes in several species that can be ascribed to minor positional differences in sample location and to natural variability. However, some taxa, notably amongst the Amphipoda, show widespread declines in their distribution and densities. The balance of evidence suggests that these changes are an acute response to the oil spill. (author)

  15. The first hop: Use of Beaufort Sea deltas by hatch-year semipalmated sandpipers

    Science.gov (United States)

    Churchwell, Roy T.; Kendall, Steve J.; Brown, Stephen C.; Blanchard, Arny L.; Hollmen, Tuula E.; Powell, Abby

    2018-01-01

    River deltas along Alaska’s Beaufort Sea coast are used by hatch-year semipalmated sandpipers (Calidris pusilla) after leaving their terrestrial natal sites, but the drivers of their use of these stopover sites on the first “hop” of fall migration are unknown. We quantified sandpiper temporal distribution and abundance as related to food resources at three river deltas during the beginning of their fall migration (post-breeding period) to compare the habitat quality among these deltas. We conducted population counts, sampled invertebrates, and captured birds to collect blood samples from individuals for triglyceride and stable isotope analyses to determine fattening rates and diet. Patterns of sandpiper and invertebrate abundance were complex and varied among deltas and within seasons. River deltas were used by sandpipers from late July to late August, and peak sandpiper counts ranged from 1000 to 4000 individuals, of which 98% were hatch-year semipalmated sandpipers. Isotopic signatures from blood plasma samples indicated that birds switched from a diet of upland tundra to delta invertebrate taxa as the migration season progressed, suggesting a dependence on delta invertebrates. Despite differences in diet among deltas, we found no differences in fattening rates of juvenile sandpipers as indicated by triglyceride levels. The number of sandpipers was positively associated with abundance of Amphipoda and Oligochaeta at the Jago and Okpilak-Hulahula deltas; an isotopic mixing model indicated that sandpipers consumed Amphipoda and Oligochaeta at Jago, mostly Chironomidae at Okpilak-Hulahula and Spionidae at Canning. Regardless of the difference in sandpiper diets at the Beaufort Sea deltas, their similar fattening rates throughout the season indicate that all of these stopover sites provide a critical food resource for hatch-year sandpipers beginning their first migration.

  16. Işıklı Gölü ve Kaynaklarının (Çivril-Denizli Crustacea Faunası.

    Directory of Open Access Journals (Sweden)

    Cem Aygen

    2015-12-01

    Full Text Available Bu çalışmada, Işıklı Gölü Crustacea faunasının taksonomik açıdan incelenmesi hedeflenmiştir. Bu amaçla Şubat 1998-Ocak 1999 ayları arasında, gölde ve göle akan kaynak bölgesinde belirlenen 6 istasyondan aylık periyotlarla biyolojik örnekler ve su örnekleri alınmıştır. Araştırma sonunda Işıklı Gölü ve Kaynağı’nda bulunan Crustacea faunasının başlıca Cladocera (16 tür, Copepoda (12 tür, Ostracoda (1 tür, Amphipoda (2 tür, Isopoda (1 tür, Mysidacea (1 tür ve Decapoda (1 tür gruplarından oluştuğu saptanmıştır. Tespit edilen türlerden Cladocera grubundan Diaphanosoma brachyurum, Diaphanosoma mongolianum, Ceriodaphnia pulchella, Simocephalus vetulus, Macrothrix laticornis, Alona rectangula, Alona guttata, Graptoleberis testudinaria, Leydigia leydigi, Biapertura affinis, Chydorus sphaericus, Pleuroxus aduncus ve Disparalona rostrata; Copepoda grubundan Macrocyclops albidus, Eucyclops serrulatus, Eucyclops speratus, Eucyclops macruroides, Metacyclops gracilis, Mesocyclops leuckarti, Cyclops vicinus, Cyclops abyssorum, Cyclops strenuus, Megacyclops viridis, Acanthocyclops robustus, Canthocamptus staphylinus; Ostracoda grubundan Psychrodromus olivaceus; Amphipoda grubundan Gammarus balcanicus, Gammarus obnixus; Isopoda grubundan Asellus aquaticus türleri Işıklı Gölü’nden ilk kez bildirilmektedir

  17. Antropología del cuerpo y el dolor

    OpenAIRE

    Muñoz Mainato, Manuel Enrique

    2016-01-01

    El culto al cuerpo está presente en todas las culturas y épocas históricas, así como “la experiencia del dolor” que ha conducido a los seres humanos al ejercicio del dominio y del poder de unos sobre otros mediante la aplicación de dolor sobre los cuerpos; verbigracia el dominio ideológico de tinte religioso ejercido por los patriarcas hebreos, los cultos sumerios, mesopotámicos, egipcios, griegos, romanos, aztecas, mayas, incas, etc. Durante el Medievo se constató esta realidad c...

  18. Operation & Maintenance Environmental Impact Statement for the Federal Facilities at Sault Ste. Marie, Michigan, Addressing Limited Season Extension of Operation. Supplement.

    Science.gov (United States)

    1979-10-01

    azteca Aca r ina I sopoda Ar renur us Asellus Lirceus Castropoda Anic ola Diptera Campe loma Tipulidae (S) Gyraulus Ceratopogonidae Helisoma...turbidity could affect the primary productivity in the area for a brief period. Solar energy entering a body of water is converted by microscopic...8217. 4 U 0 Cd co m4 Z i C4 i dio C. ’. U ’U d 0 . C dd W 𔃾 Cd 4 d d > d - U 0 - C ’. i d . - d 44tl n C> - _4 In 0 0 -d W - C C. U : A i ’U 0 di -0 A

  19. Investigación y análisis de la competitividad en el puerto de Veracruz (Estados Unidos Mexicanos)

    OpenAIRE

    Flórez Vanegas, Alejandra; Moreno Fonseca, William

    2016-01-01

    Esta investigación describe la situación portuaria del estado de Veracruz, ubicado en México, con el fin de analizar sus capacidades, infraestructura y funcionamiento, permitiendo una visualización de los modelos usados por el puerto, registrar sus prácticas, entre otros. Partiendo del funcionamiento, algunas estrategias y destrezas que se realizan en el puerto Azteca se tomarán como ejemplo, asimismo se realizará un análisis para el puerto de Buenaventura ubicado en Colombia. Lo anterior...

  20. Estudio de un cemento de las ruinas de Teotihuacan

    Directory of Open Access Journals (Sweden)

    Goldschimdt, A.

    1981-06-01

    Full Text Available Not available

    Se estudió un mortero de cemento portland de aproximadamente 30 años expuesto a la intemperie y otro mortero de las ruinas de Teotihuacan, mediante Microsonda (EM y Microscopía Electrónica de Barrido (SEM. Mostrándose la diferencia entre ambos morteros y evidenciando la semejanza, del de Teotihuacan -cuya edad es anterior a la conquista del Imperio Azteca- con el mortero puzolánico Romano.

  1. El largo camino de Juan Preciado hacia el Mictlán

    OpenAIRE

    Bartolomé Martínez, Cristina

    2011-01-01

    Podríamos establecer que lo que se esconde tras el viaje de Juan Preciado no es sencillamente el mito azteca del Mictlán, sino el arquetipo universal del alma que regresa a las profundidades del ser en un viaje introspectivo que encontraría su correspondencia en mitos de todas las culturas que posean una cosmovisión, una manera propia de interpretar el mundo y, lo que es aún más inquietante, la vida.

  2. Tezcatlipoca (post)moderno : reinterpretaciones de la figura del Espejo Humeante en la narrativa mexicana contemporánea

    OpenAIRE

    Andzel-O'Shanahan, Edyta

    2017-01-01

    El propósito del presente trabajo es el de rastrear la presencia de la figura de Tezcatlipoca y de los mitos relacionados con él en la literatura mexicana de los siglos XX y XXI. Uno de los dioses principales en la cosmovisión azteca, el omnipotente y omnipresente dios de la guerra, capaz de entender los secretos de los corazones humanos y de revelar el destino, reaparece en la narrativa contemporánea con todo su rico simbolismo. Las reelaboraciones de su imagen se inscriben, sin embargo, den...

  3. Inhibidores de la germinación en el residuo seco del tallo del amaranto (Amaranthus hypochondriacus)

    OpenAIRE

    Tejeda-Sartorius, Olga; Escalante-Estrada, J. Alberto; Soto-Hernández, Marcos; Rodríguez-González, Ma. Teresa; Vibrans, Heike; Ramírez-Guzmán, Martha E.

    2004-01-01

    Se evaluó el efecto del extracto acuoso del residuo seco del tallo del amaranto (Amaranthus hypochondriacus L. var. Azteca) a diferentes concentraciones, en la germinación y longitud de radícula y vástago de Amaranthus hybridus L. Dicho extracto, a 108 y 54 ppm inhibió la germinación de la especie en 100% y 68.42%, respectivamente, disminuyendo significativamente la longitud del vástago y la radícula, cuando la inhibición de la germinación no fue total. Se identificaron los ácidos ferúlico (A...

  4. Seasonal trophic activity of the aquatic morphotype of Atelognathus patagonicus (Anura, Neobatrachia and prey availability in the littoral benthos of a permanent pond in Argentinean Patagonia

    Directory of Open Access Journals (Sweden)

    María Elena Cuello

    2009-12-01

    Full Text Available The diet of the aquatic morphotype of Atelognathus patagonicus was studied in frogs collected from the Laguna Verde pond (Laguna Blanca National Park, Neuquén, Argentina. The content of 35 gastrointestinal tracts of post-metamorphic specimens from November 2003 to April 2006 was related to the composition of the benthos in their microhabitat. Number, size, occurrence and relative importance of preys, diversity of the diet, trophic niche breadth and electivitywere estimated for each season of the year. The diet consisted of aquatic arthropods. The composition of both the benthos and the food (number and occurrence of organisms in the diet were dominated by the amphipod Hyalella sp. The relative importance (IRI of Hyalella sp. in the diet was over 99% in summer and autumn, and 100% in winter and spring. Diptera and Copepoda in summer, and Dytiscidae and Ostracoda in autumn, had seasonal IRI values ≤ 0.2%. Trophic niche breadth was very low in summer and autumn, and null (= 0 in winter and spring. The mean number of preys per individual was highest in spring (19 preys/frog and lowest in winter (4 preys/frog. Frogs continued with their trophic activity in winter, even when the surface of the pond was frozen. There is a correspondence between the frogs’ main food item and its presence in the benthos.

  5. OCCURRENCE IN THE SOIL AND DISPERSAL OF Lecanicillium lecanii, A FUNGAL PATHOGEN OF THE GREEN COFFEE SCALE (Coccus viridis AND COFFEE RUST (Hemileia vastatrix

    Directory of Open Access Journals (Sweden)

    Doug William Jackson

    2012-08-01

    Full Text Available The fungus Lecanicillium lecanii attacks the green scale (Coccus viridis, a pest of coffee, and is also a hyperparasite of coffee rust (Hemileia vastatrix. Knowledge of the epizootiology of this fungus is potentially important for conservation biological control in coffee agroecosystems. The presence of viable propagules of L. lecanii in the soil, a possible environmental reservoir, was assessed using two baiting methods: the standard Galleria mellonella bait method and a C. viridis bait method. Infectious propagules of L. lecanii were detected in soil samples taken from a 45 ha study plot, both nearby and far from recent epizootics of L. lecanii. To test the potential for the transmission of L. lecanii conidia from the soil via rain splash or wind, coffee seedlings with populations of C. viridis were placed near L. lecanii-inoculated soil and then subjected to artificial rain and wind treatments. Rain splash was shown to be a potential transmission mechanism. Dispersal of L. lecanii conidia by the ant Azteca instabilis was tested using field and laboratory ant-exclusion experiments. Azteca instabilis was shown to transport conidia of L. lecanii; however, dispersal by A. instabilis may not be important under field conditions.

  6. Spider diversity in coffee agroecosystems: the influence of agricultural intensification and aggressive ants.

    Science.gov (United States)

    Marín, Linda; Perfecto, Ivette

    2013-04-01

    Spiders are a very diverse group of invertebrate predators found in agroecosystems and natural systems. However, spider distribution, abundance, and eventually their ecological function in ecosystems can be influenced by abiotic and biotic factors such as agricultural intensification and dominant ants. Here we explore the influence of both agricultural intensification and the dominant arboreal ant Azteca instabilis on the spider community in coffee agroecosystems in southern Mexico. To measure the influence of the arboreal ant Azteca instabilis (F. Smith) on the spider community inhabiting the coffee layer of coffee agroecosystems, spiders were collected from coffee plants that were and were not patrolled by the ant in sites differing in agricultural intensification. For 2008, generalized linear mixed models showed that spider diversity was affected positively by agricultural intensification but not by the ant. However, results suggested that some spider species were associated with A. instabilis. Therefore, in 2009 we concentrated our research on the effect of A. instabilis on spider diversity and composition. For 2009, generalized linear mixed models show that spider richness and abundance per plant were significantly higher in the presence of A. instabilis. In addition, analyses of visual counts of insects and sticky traps data show that more resources were present in plants patrolled by the ant. The positive effect of A. instabilis on spiders seems to be caused by at least two mechanisms: high abundance of insects and protection against predators.

  7. Long-term dynamics of the state of the fouling community in the Odessa Bay (Black Sea

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    A. Y. Varigin

    2017-04-01

    Full Text Available This article examines the long-term dynamics of the qualitative and quantitative characteristics of the coastal fouling community of OdessaBay(Black Sea for the last 40 years. It compares the data on this community obtained by different researchers in 1976, 1994 and 2016 . The number of species included in the fouling community decreased from 103 (1976 to 43 (1994 and then rose to 62 by 2016. As a possible reason for this reduction in the species composition of the community the influence of large-scale anthropogenic eutrophication, which was already strongly evident in the north-western part of the Black Seain the 1970s, is proposed. This phenomenon was accompanied by periodic outbreaks of mass abundance of planktonic algae, secondary water pollution, the development of hypoxia and a frequent suffocation effect on the benthos, which caused the disappearance from the community of 41 species of invertebrates. The reduction in the number of species affected representatives of the following taxons: Polychaeta, Amphipoda, Gastropoda and Bivalvia. Currently, the core of the community includes the same species of invertebrates as in the past. It is based on Bivalvia mussels Mytilus galloprovincialis. Among the attached forms , Mytilaster lineatus (Bivalvia and Amphibalanus improvisus (Cirripedia play a leading role, and among mobile – representatives of Polychaeta, Isopoda, Amphipoda and Gastropoda. It is shown that 10 of the 25 species, recorded the first time for this community in the 1970s, have become abundant in modern conditions. The primacy in the relative density in the composition of the community at the present time has passed from the amphipod crustaceans to bivalve molluscs. The highest relative biomass, both in the past and in the present-day conditions was observed in representatives of Bivalvia. The structure of the resistance of the fouling community to the effects of unstable environmental factors specific to the coastal zone is

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

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    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

  9. Diversity and effective population size of four horse breeds from microsatellite DNA markers in South-Central Mexico

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    J. F. Vázquez-Armijo

    2017-06-01

    Full Text Available The South-Central region of Mexico has experienced a sizeable introduction of purebred horses for recreational aims. A study was designed to assess effective population sizes and genetic diversity and to verify the genetic integrity of four horse breeds. Using a 12-microsatellite panel, Quarter Horse, Azteca, Thoroughbred and Creole (CRL horses were sampled and analysed for diversity and genetic structure. Genetic diversity parameters showed high numbers of heterozygous horses but small effective population sizes in all breeds. Population structure results suggested some degree of admixture of CRL with the other reference breeds. The highly informative microsatellite panel allowed the verification of diversity in introduced horse populations and the confirmation of small effective population sizes, which suggests a risk for future breed integrity.

  10. Spatial pattern and ecological process in the coffee agroforestry system.

    Science.gov (United States)

    Perfecto, Ivette; Vandermeer, John

    2008-04-01

    The coffee agroforestry system provides an ideal platform for the study of spatial ecology. The uniform pattern of the coffee plants and shade trees allows for the study of pattern generation through intrinsic biological forces rather than extrinsic habitat patchiness. Detailed studies, focusing on a key mutualism between an ant (Azteca instabilis) and a scale insect (Coccus viridis), conducted in a 45-ha plot in a coffee agroforestry system have provided insights into (1) the quantitative evaluation of spatial pattern of the scale insect Coccus viridis on coffee bushes, (2) the mechanisms for the generation of patterns through the combination of local satellite ant nest formation and regional control from natural enemies, and (3) the consequences of the spatial pattern for the stability of predator-prey (host-parasitoid) systems, for a key coccinelid beetle preying on the scale insects and a phorid fly parasitoid parasitizing the ant.

  11. El Centro Histórico de la Ciudad de México al Inicio del Siglo XXI

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    Alejandro Suárez Pareyón

    2004-01-01

    Full Text Available La Ciudad de México tiene un centro cuyo origen se remonta a la ciudad azteca fundada hace siete siglos y los conquistadores españoles refundaron la ciudad conservando la esencia del principio ordenador prehispánico, la riqueza acumulada a lo largo de la historia se manifiesta en la gran concentración de sitios y edificios que le han significado el reconocimiento internacional de Patrimonio de la Humanidad. El Centro Histórico es un reflejo de toda la heterogeneidad social, económica y cultural que representa una de las más grandes metrópolis del mundo, es un espacio urbano lleno de contrastes en donde el gobierno de la ciudad ha emprendido un proceso de planificación urbana para la regeneración integral de las funciones que le han sido representativas a lo largo de la historia.

  12. Conflict over reproduction in an ant-plant symbiosis: why Allomerus octoarticulatus ants sterilize Cordia nodosa trees.

    Science.gov (United States)

    Frederickson, Megan E

    2009-05-01

    The evolutionary stability of mutualism is thought to depend on how well the fitness interests of partners are aligned. Because most ant-myrmecophyte mutualisms are persistent and horizontally transmitted, partners share an interest in growth but not in reproduction. Resources invested in reproduction are unavailable for growth, giving rise to a conflict of interest between partners. I investigated whether this explains why Allomerus octoarticulatus ants sterilize Cordia nodosa trees. Allomerus octoarticulatus nests in the hollow stem domatia of C. nodosa. Workers protect C. nodosa leaves against herbivores but destroy inflorescences. Using C. nodosa trees with Azteca ants, which do not sterilize their hosts, I cut inflorescences off trees to simulate sterilization by A. octoarticulatus. Sterilized C. nodosa grew faster than control trees, providing evidence for a trade-off between growth and reproduction. Allomerus octoarticulatus manipulates this trade-off to its advantage; sterilized trees produce more domatia and can house larger, more fecund colonies.

  13. When attempts at robbing prey turn fatal

    Science.gov (United States)

    Dejean, Alain; Corbara, Bruno; Azémar, Frédéric; Carpenter, James M.

    2012-07-01

    Because group-hunting arboreal ants spread-eagle insect prey for a long time before retrieving them, these prey can be coveted by predatory flying insects. Yet, attempting to rob these prey is risky if the ant species is also an effective predator. Here, we show that trying to rob prey from Azteca andreae workers is a fatal error as 268 out of 276 potential cleptobionts (97.1 %) were captured in turn. The ant workers hunt in a group and use the "Velcro®" principle to cling firmly to the leaves of their host tree, permitting them to capture very large prey. Exceptions were one social wasp, plus some Trigona spp. workers and flies that landed directly on the prey and were able to take off immediately when attacked. We conclude that in this situation, previously captured prey attract potential cleptobionts that are captured in turn in most of the cases.

  14. Asymmetric dispersal and colonization success of Amazonian plant-ants queens.

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    Emilio M Bruna

    Full Text Available The dispersal ability of queens is central to understanding ant life-history evolution, and plays a fundamental role in ant population and community dynamics, the maintenance of genetic diversity, and the spread of invasive ants. In tropical ecosystems, species from over 40 genera of ants establish colonies in the stems, hollow thorns, or leaf pouches of specialized plants. However, little is known about the relative dispersal ability of queens competing for access to the same host plants.We used empirical data and inverse modeling--a technique developed by plant ecologists to model seed dispersal--to quantify and compare the dispersal kernels of queens from three Amazonian ant species that compete for access to host-plants. We found that the modal colonization distance of queens varied 8-fold, with the generalist ant species (Crematogaster laevis having a greater modal distance than two specialists (Pheidole minutula, Azteca sp. that use the same host-plants. However, our results also suggest that queens of Azteca sp. have maximal distances that are four-sixteen times greater than those of its competitors.We found large differences between ant species in both the modal and maximal distance ant queens disperse to find vacant seedlings used to found new colonies. These differences could result from interspecific differences in queen body size, and hence wing musculature, or because queens differ in their ability to identify potential host plants while in flight. Our results provide support for one of the necessary conditions underlying several of the hypothesized mechanisms promoting coexistence in tropical plant-ants. They also suggest that for some ant species limited dispersal capability could pose a significant barrier to the rescue of populations in isolated forest fragments. Finally, we demonstrate that inverse models parameterized with field data are an excellent means of quantifying the dispersal of ant queens.

  15. Do herbivores eavesdrop on ant chemical communication to avoid predation?

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    David J Gonthier

    Full Text Available Strong effects of predator chemical cues on prey are common in aquatic and marine ecosystems, but are thought to be rare in terrestrial systems and specifically for arthropods. For ants, herbivores are hypothesized to eavesdrop on ant chemical communication and thereby avoid predation or confrontation. Here I tested the effect of ant chemical cues on herbivore choice and herbivory. Using Margaridisa sp. flea beetles and leaves from the host tree (Conostegia xalapensis, I performed paired-leaf choice feeding experiments. Coating leaves with crushed ant liquids (Azteca instabilis, exposing leaves to ant patrolling prior to choice tests (A. instabilis and Camponotus textor and comparing leaves from trees with and without A. instabilis nests resulted in more herbivores and herbivory on control (no ant-treatment relative to ant-treatment leaves. In contrast to A. instabilis and C. textor, leaves previously patrolled by Solenopsis geminata had no difference in beetle number and damage compared to control leaves. Altering the time A. instabilis patrolled treatment leaves prior to choice tests (0-, 5-, 30-, 90-, 180-min. revealed treatment effects were only statistically significant after 90- and 180-min. of prior leaf exposure. This study suggests, for two ecologically important and taxonomically diverse genera (Azteca and Camponotus, ant chemical cues have important effects on herbivores and that these effects may be widespread across the ant family. It suggests that the effect of chemical cues on herbivores may only appear after substantial previous ant activity has occurred on plant tissues. Furthermore, it supports the hypothesis that herbivores use ant chemical communication to avoid predation or confrontation with ants.

  16. Strike fast, strike hard: the red-throated caracara exploits absconding behavior of social wasps during nest predation.

    Science.gov (United States)

    McCann, Sean; Moeri, Onour; Jones, Tanya; Scott, Catherine; Khaskin, Grigori; Gries, Regine; O'Donnell, Sean; Gries, Gerhard

    2013-01-01

    Red-throated Caracaras Ibycter americanus (Falconidae) are specialist predators of social wasps in the Neotropics. It had been proposed that these caracaras possess chemical repellents that allow them to take the brood of wasp nests without being attacked by worker wasps. To determine how caracaras exploit nests of social wasps and whether chemical repellents facilitate predation, we: (1) video recorded the birds attacking wasp nests; (2) analyzed surface extracts of the birds' faces, feet, and feathers for potential chemical repellents; and (3) inflicted mechanical damage on wasp nests to determine the defensive behavior of wasps in response to varying levels of disturbance. During caracara predation events, two species of large-bodied wasps mounted stinging attacks on caracaras, whereas three smaller-bodied wasp species did not. The "hit-and-run" predation tactic of caracaras when they attacked nests of large and aggressive wasps reduced the risk of getting stung. Our data reveal that the predation strategy of caracaras is based on mechanical disturbance of, and damage to, target wasp nests. Caracara attacks and severe experimental disturbance of nests invariably caused wasps to abscond (abandon their nests). Two compounds in caracara foot extracts [sulcatone and iridodial] elicited electrophysiological responses from wasp antennae, and were also present in defensive secretions of sympatric arboreal-nesting Azteca ants. These compounds appear not to be wasp repellents but to be acquired coincidentally by caracaras when they perch on trees inhabited with Azteca ants. We conclude that caracara predation success does not depend on wasp repellents but relies on the absconding response that is typical of swarm-founding polistine wasps. Our study highlights the potential importance of vertebrate predators in the ecology and evolution of social wasps.

  17. Características de las instalaciones adaptadas

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    Editorial, Equipo

    1968-11-01

    Full Text Available A number of secondary adaptations were carried out at some of the Olympic installations. These included the improvement of the spectator seats, zones for the information services, increase in the number of wash rooms, so that the Olympic formal requirements could be met at the following specific Olympic sites: The Mexico Arena, for the boxing competitions; the Avandaro & Campo Marte, for the riding competitions; the Azteca Stadium, for football; the Auditorio Nacional, for gymnastics; the Estadio Municipal y Secundario de la «Magdalena Mixhuca », for hockey; the Teatro de los Insurgentes, for weightlif ting ; the Pista Hielo Insurgentes, for wrestling; Club de Yates at Acapulco, for sailing; Pista Hielo Revolución, for volleyball; and the Piscina de la Ciudad Universitaria, for water polo.Se hicieron una serie de adaptaciones secundarias: mejora de los asientos para espectadores, creación de zonas para los servicios de información, ampliación del número de cancelas y aseos, etcétera, de modo que satisficiesen los requisitos olímpicos reglamentarios en las siguientes instalaciones ya existentes: El Arena México, para la celebración de los combates de boxeo; el Avándaro y Campo Marte, para las pruebas ecuestres; Estadio Azteca, fútbol; Auditorio Nacional, gimnasia; Estadio Municipal y Secundarios de la «Magdalena Mixhuca», hockey; Teatro de los Insurgentes, levantamiento de pesas; Pista Hielo Insurgentes, lucha; Club de Yates en Acapulco, vela; Pista Hielo Revolución, balonvolea, y Piscina de la Ciudad Universitaria, water-polo.

  18. Meiobenthos assemblages in the mekong estuarine system with special focus on free-living marine nematodes

    Science.gov (United States)

    Quang, Ngo Xuan; Vanreusel, Ann; Smol, Nic; Chau, Nguyen Ngoc

    2010-12-01

    Meiobenthos assemblages in eight estuaries of the Mekong river system were investigated in August 2008 (from the Cua Tieu estuary to the Tran De estuary). In each estuary, one sampling station was established for meiobenthos sampling. Twelve major taxa of meiobenthos were recorded in this estuarine system, including Nematoda, Copepoda, Turbellaria, Polychaeta, Oligochaeta, Tardigrada, Bivalvia, Ostracoda, Amphipoda, Cumacea, Gastrotricha, Gastropoda, and Crustacean Nauplii larvae. The densities of the meiobenthos range from 581 to 3168 inds/10 cm2. Nematodes always occupy the highest numbers with a percentage ranging from 64-99%. There are 135 nematode genera recorded in this study with the following as dominant genera Desmodora, Leptolaimus, Halalaimus, Thalassomonhystera, Theristus, Daptonema, Rhynchonema, Parodontophora, and Oncholaimus. Although the biodiversity of the meiobenthos at higher taxa level is not high compared to other marine environments, the estimates of nematode biodiversity at the genus level indicates high values. The increase in number of genera with increasing sampling intensity illustrate that the diversity is underestimated and would have been higher if the authors had considered a larger number of individuals, more replicates per station, and more sampling stations.

  19. Taxocenosis of mollusks and crustaceans on roots of rhizophora mangle (rhizophoraceae) at Cispata Bay, Cordoba, Colombia

    International Nuclear Information System (INIS)

    Quiros R, Jorge Alexander; Arias, Jorge Enrique

    2013-01-01

    Despite the existing knowledge on the ecology of mangroves at Cispata Bay, few studies have focused on the association of invertebrates on red mangrove roots, so between December 2010 and September 2011, it was characterized Taxocenosis of mollusks and crustaceans on roots of rhizophora mangle in two study sites at Cispata Bay, Colombia. For the collections of biological material were randomly taken three red mangrove roots with a diameter homogeneous by sampling station. Mollusks and crustaceans were obtained from the root surface with a scraping knife then were removed and fixed in 10 % formalin for later identification to species using specialized taxonomic keys. of the 12289 individuals collected in the four samples, 10470 belonged to the phylum Mollusca (85,2 %) and the remaining 1819 to subphylum Crustacea (14,8 %). for mollusks were identified 14 species distributed in 11 families and two classes; bivalvia and gastropoda. for crustaceans were identified 24 species distributed in 16 families and four orders; sessillia, decapoda, isopoda and amphipoda. in both sectors sampling mytella charruana, balanuseburneus and crassostrea rhizophorae were the most important species in terms of abundance, however mollusks like m. charruana and B. eburneus have a great ability to adapt and adjust to changing hydroclimatic, which was reflected in the dominance of these species in the sector with the greatest influence Sinu River. The presence of crustaceans Petrolisthes armatus and Aratus pisonii in the sector with more proximity to the Caribbean Sea indicate that are species with great mobility and physiological adaptation mechanisms.

  20. Do insect repellents induce drift behaviour in aquatic non-target organisms?

    Science.gov (United States)

    Fink, Patrick; Moelzner, Jana; Berghahn, Ruediger; von Elert, Eric

    2017-01-01

    Synthetic insect repellents are compounds applied to surfaces to discourage insects, mainly mosquitoes, from landing on those surfaces. As some of these repellents have repeatedly been detected in surface waters at significant concentrations, they may also exert repellent effects on aquatic non-target organisms. In running water systems, aquatic invertebrates actively enter downstream drift in order to avoid unfavourable environmental conditions. We thus tested the hypothesis that the widely used insect repellents DEET (N,N-Diethyl-m-toluamide), EBAAP (3-[N-butyl-N-acetyl]-aminopropionic acid ethyl ester) and Icaridin (1-piperidinecarboxylic acid 2-(2-hydroxyethyl)-1-methylpropyl ester) induce downstream drift behaviour in the aquatic invertebrates Gammarus pulex (Crustacea, Amphipoda) and Cloeon dipterum (Insecta, Ephemeroptera), using a laboratory-scale drift assay. We found no clear increase in the drift behaviour of both invertebrate species across a concentration gradient of eight orders of magnitude and even beyond maximum environmental concentrations for any of the three repellents. We found no evidence for a direct drift-inducing activity of insect repellents on aquatic non-target organisms. Copyright © 2016 Elsevier Ltd. All rights reserved.

  1. The opportunistic feeding and reproduction strategies of the annual fish Cynopoecilus melanotaenia (Cyprinodontiformes: Rivulidae inhabiting ephemeral habitats on southern Brazil

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    Cristina da Silva Gonçalves

    Full Text Available Most Rivulidae fishes are popularly known as annual fishes which live in ephemeral environments such as pools, that obligatorily dry out seasonally causing the death of adult individuals. They have unique biological characteristics such as small body size, early sexual maturation, continuous reproduction, an elaborated courtship behavior, and a great reproductive capacity among fishes. The rivulids are widely distributed in North, Central and South America. In this study, the diet and reproductive biology of Cynopoecilus melanotaenia was analyzed. A total of 263 specimens were collected and the analysis of 233 gastrointestinal contents revealed an invertivorous diet composed mainly of small crustaceans (Cladocera, Amphipoda, and Ostracoda and immature insects (Chaoboridae, Culicidae, Syrphidae, but mainly Chironomidae larvae. Lepidophagy on male's diet was also registered. Fecundity was estimated by analyzing 59 pairs of mature ovaries and ranged from 2 to 157 oocytes (mean, 19 ± 26[SD]. The species has fractional spawning, a strategy to increase the chance of survival to prolonged depletions. This study is the first to investigate the reproductive biology of C. melanotaenia. The results confirmed the opportunistic character of the rivulid C. melanotaenia and provided unreported reproductive information that may aid conservation of the species.

  2. Field and laboratory investigations on the effects of road salt (NaCl) on stream macroinvertebrate communities

    International Nuclear Information System (INIS)

    Blasius, B.J.; Merritt, R.W.

    2002-01-01

    Short-term exposure to road salt did not significantly affect stream macro-invertebrate communities. - Field and laboratory experiments were conducted to examine the effects of road salt (NaCl) on stream macroinvertebrates. Field studies investigated leaf litter processing rates and functional feeding group composition at locations upstream and downstream from point source salt inputs in two Michigan, USA streams. Laboratory studies determined the effects of increasing NaCl concentrations on aquatic invertebrate drift, behavior, and survival. Field studies revealed that leaves were processed faster at upstream reference sites than at locations downstream from road salt point source inputs. However, it was sediment loading that resulted in partial or complete burial of leaf packs, that affected invertebrate activity and confounded normal leaf pack colonization. There were no significant differences that could be attributed to road salt between upstream and downstream locations in the diversity and composition of invertebrate functional feeding groups. Laboratory drift and acute exposure studies demonstrated that drift of Gammarus (Amphipoda) may be affected by NaCl at concentrations greater than 5000 mg/l for a 24-h period. This amphipod and two species of limnephilid caddisflies exhibited a dose response to salt treatments with 96-h LC 50 values of 7700 and 3526 mg NaCl/l, respectively. Most other invertebrate species and individuals were unaffected by NaCl concentrations up to 10,000 mg/l for 24 and 96 h, respectively

  3. Riffle zoobenthos in streams receiving acid mine drainage

    Energy Technology Data Exchange (ETDEWEB)

    Koryak, M; Shapiro, M A; Sykora, J L

    1972-01-01

    The bottom fauna of a stream polluted by acid mine drainage, was studied, using the standard methods of sample collecting. In localities immediately influenced by mine drainage, where very low pH values and high acidities prevail, the effect of acid mine wastes on the ecology and composition of the benthic fauna is, in general, similar to the effect of organic pollution. In these areas we found high numbers of individuals comprised of a few species. In the zones of active neutralization, where iron hydroxides are deposited, species diversity slightly increases but the biomass is very low. The most numerous invertebrates in the stream sections exhibiting high acidity and low pH are midge larvae, especially Tendipes gr. riparius. The number of insect groups present increases steadily with progressive neutralization until crustacea (amphipoda) and oligochaeta appear, indicating considerable improvement in water quality. The supply of desirable benthic fish food (Tendipes ssp.) is very high in the parts of the stream where low pH, high acidity, and high ferrous iron concentrations prevail. Unfortunately, fish cannot survive under these conditions to utilize this abundant food supply. On the other hand, in the less acidic zones, where fish could possibly survive, the deposition of ferric iron drastically diminishes the total biomass of benthic organisms and therefore severely limits fish populations.

  4. The Early Shorebird Will Catch Fewer Invertebrates on Trampled Sandy Beaches.

    Science.gov (United States)

    Schlacher, Thomas A; Carracher, Lucy K; Porch, Nicholas; Connolly, Rod M; Olds, Andrew D; Gilby, Ben L; Ekanayake, Kasun B; Maslo, Brooke; Weston, Michael A

    2016-01-01

    Many species of birds breeding on ocean beaches and in coastal dunes are of global conservation concern. Most of these species rely on invertebrates (e.g. insects, small crustaceans) as an irreplaceable food source, foraging primarily around the strandline on the upper beach near the dunes. Sandy beaches are also prime sites for human recreation, which impacts these food resources via negative trampling effects. We quantified acute trampling impacts on assemblages of upper shore invertebrates in a controlled experiment over a range of foot traffic intensities (up to 56 steps per square metre) on a temperate beach in Victoria, Australia. Trampling significantly altered assemblage structure (species composition and density) and was correlated with significant declines in invertebrate abundance and species richness. Trampling effects were strongest for rare species. In heavily trafficked plots the abundance of sand hoppers (Amphipoda), a principal prey item of threatened Hooded Plovers breeding on this beach, was halved. In contrast to the consistently strong effects of trampling, natural habitat attributes (e.g. sediment grain size, compactness) were much less influential predictors. If acute suppression of invertebrates caused by trampling, as demonstrated here, is more widespread on beaches it may constitute a significant threat to endangered vertebrates reliant on these invertebrates. This calls for a re-thinking of conservation actions by considering active management of food resources, possibly through enhancement of wrack or direct augmentation of prey items to breeding territories.

  5. STUDY ON MACROZOOBENTHOS COMMUNITY IN THE WATERS OF THE RIVER AIR PERIKAN MUNICIPALITY OF PAGAR ALAM SOUTH SUMATRA

    Directory of Open Access Journals (Sweden)

    Rafles Tampubolon

    2017-11-01

    Full Text Available The research entitled “ Study on Macrozoobenthos Community in the Waters of the River Air Perikan Pagar Alam Municipality”, was conducted from November 2007 until March 2008. The aims of the research: to know about composition, density, diversity index, dominancy index, and similarity index, which based on the different microhabitat types. Sampling was carried out on November 2007. Five sampling stations were determined by survey method and the Purposive Sampling method was used at each sampling point to find stony, gravel, sandy and leaf pack area as a different microhabitat substrate. Twenty one orders (Ephemeroptera, Trichoptera, Diptera, Plecoptera, Collembola, Hemiptera, Odonata, Coleoptera, Lepidoptera, Megaloptera, Hymenoptera, Orthoptera, Decapoda, Plesiopora, Tricladida, Amphipoda, Isopoda, Mesogastropoda, Ctenobranchiata, Eulamellibranchiata, and Rhynchobdellida which are consisted of 70 families and 151 genera were identified from four types of substrates on each sampling station. According to this research, station 4 has the highest in composition (80 genera, and the lowest one at station 1(33 genera. The highest abundance was 12589 ind./m2 found in the station 5, and the lowest one was in the station 1 approximately 880 ind./m2. For the diversity index value, station 3 was the highest (3.1 and the lowest one was station 5 (1.9. The Dominancy index was found in station 5 at the sandy substrates was approximately 0,8 index, which dominated by Tubifex sp. There were differences species composition on each station.

  6. Effects of offshore oil drilling on benthic invertebrate communities on the Grand Banks (North Atlantic)

    Energy Technology Data Exchange (ETDEWEB)

    DeBlois, E. [Jacques Whitford Ltd., St. John' s, NL (Canada); Wight, F. [Husky Oil Operations Ltd., St. John' s, NL (Canada); Taylor, D. [DG Taylor Inc., Conception Bay South, NL (Canada); Paine, M. [Paine, Ledge and Associates, North Vancouver, BC (Canada)

    2007-07-01

    Drilling occurs at three different drill centres of the White Rose (WR) oil platform that lies 350 km offshore from St. John's Newfoundland. An extensive environmental effects monitoring (EEM) program conducted by Husky Energy is underway at the WR site. The sediment component of the program involves the measurement of physical and chemical characteristics, an assessment of toxicity in laboratory tests, and an assessment of in situ benthic invertebrate communities. Baseline sampling occurred in 2000, followed by post-drilling sampling in 2004 to 2006. The sediment is 95 per cent sand, with polychaetes and bivalves dominating the invertebrate communities. A comparative evaluation was performed for regressions between community variables and distances from drill centres before and after drilling. Concentration-response relationships between community variables and concentrations of major constituents in drilling muds (C10-C21 HCs) were also compared among years. It was shown that the biological effects on invertebrate communities were highly restricted to reductions in the amount of Paraonidae and Amphipoda near drill centres and at higher C10-C21 HC concentrations. The study revealed that the two most abundant invertebrate communities were not influenced by drilling in terms of standing crop, richness, diversity and evenness.

  7. Diversity of Tanaidacea (Crustacea: Peracarida in the world's oceans--how far have we come?

    Directory of Open Access Journals (Sweden)

    Magdalena Blazewicz-Paszkowycz

    Full Text Available Tanaidaceans are small peracarid crustaceans which occur in all marine habitats, over the full range of depths, and rarely into fresh waters. Yet they have no obligate dispersive phase in their life-cycle. Populations are thus inevitably isolated, and allopatric speciation and high regional diversity are inevitable; cosmopolitan distributions are considered to be unlikely or non-existent. Options for passive dispersion are discussed. Tanaidaceans appear to have first evolved in shallow waters, the region of greatest diversification of the Apseudomorpha and some tanaidomorph families, while in deeper waters the apseudomorphs have subsequently evolved two or three distinct phyletic lines. The Neotanaidomorpha has evolved separately and diversified globally in deep waters, and the Tanaidomorpha has undergone the greatest evolution, diversification and adaptation, to the point where some of the deep-water taxa are recolonizing shallow waters. Analysis of their geographic distribution shows some level of regional isolation, but suffers from inclusion of polyphyletic taxa and a general lack of data, particularly for deep waters. It is concluded that the diversity of the tanaidomorphs in deeper waters and in certain ocean regions remains to be discovered; that the smaller taxa are largely understudied; and that numerous cryptic species remain to be distinguished. Thus the number of species currently recognized is likely to be an order of magnitude too low, and globally the Tanaidacea potentially rival the Amphipoda and Isopoda in diversity.

  8. Food of forage fishes in western Lake Erie, 1975-76

    Science.gov (United States)

    Muth, Kenneth M.; Busch, Wolf-Dieter N.

    1989-01-01

    In western Lake Erie in the summer and fall of 1975–1976, food eaten by seven forage fishes—emerald shiner (Notropis atherinoides), spottail shiner (Notropis hudsonius), trout-perch (Percopsis omiscomaycus), andyoung-of-the-year (YOY) of alewife (Alosa pseudoharengus), gizzard shad (Dorosoma cepedianum), white bass (Morone chrysops), and freshwater drum (Aplodi-notus grunniens)—was divided among six major taxa: Cladocera, Copepoda, Diptera, Ostracoda, Amphipoda, and Algae. In addition, fish were eaten by YOY white bass, and Rotifera were consumed by YOY gizzard shad. Interspecies diet overlap indices, calculated to compare the food of the different species and to evaluate diet similarities, were usually highest for YOY white bass and YOY freshwater drum when compared with the other species and usually lowest between emerald shiners and all other forage fishes. Understanding the feeding interactions among fishes that could influence production at the forage-food level of the food web could provide insight into how cascading trophic interactions influence the production of piscivorous predators.

  9. Thiacloprid affects trophic interaction between gammarids and mayflies

    International Nuclear Information System (INIS)

    Englert, D.; Bundschuh, M.; Schulz, R.

    2012-01-01

    Neonicotinoid insecticides like thiacloprid enter agricultural surface waters, where they may affect predator–prey-interactions, which are of central importance for ecosystems as well as the functions these systems provide. The effects of field relevant thiacloprid concentrations on the leaf consumption of Gammarus fossarum (Amphipoda) were assessed over 96 h (n = 13–17) in conjunction with its predation on Baetis rhodani (Ephemeroptera) nymphs. The predation by Gammarus increased significantly at 0.50–1.00 μg/L. Simultaneously, its leaf consumption decreased with increasing thiacloprid concentration. As a consequence of the increased predation at 1.00 μg/L, gammarids' dry weight rose significantly by 15% compared to the control. At 4.00 μg/L, the reduced leaf consumption was not compensated by an increase in predation causing a significantly reduced dry weight of Gammarus (∼20%). These results may finally suggest that thiacloprid adversely affects trophic interactions, potentially translating into alterations in ecosystem functions, like leaf litter breakdown and aquatic-terrestrial subsidies. - Highlights: ► Field relevant thiacloprid concentrations affected gammarid and mayfly interaction. ► Gammarus leaf consumption and predation success is adversely affected. ► Gammarus growth increased due to higher predation at 1.0 μg thiacloprid/L. ► The study's results are discussed in the context of ecosystem functions. - Field relevant thiacloprid concentrations affect species interactions, which may translate to alterations in ecosystem functions.

  10. Atypical feeding behavior of Long-tailed Ducks in the wake of a commercial fishing boat while clamming

    Science.gov (United States)

    Perry, Matthew; Osenton, Peter C.; White, Timothy P.

    2017-01-01

    A foraging group of Clangula hyemalis (Long-tailed Duck) was observed on 10 February 2010 diving behind a commercial boat that was clamming near Monomoy Island, Nantucket Sound, MA. We used a shotgun to collect 9 of the ducks, and our analyses of gizzard and gullet (esophagus and proventriculus) revealed 37 food items in the gizzard and 16 in the gullet. Mollusca were the dominant food in the gizzard (49%), whereas Crustacea were dominant in the gullet (57%). Crustacea were the second most important food in the gizzard (38%), whereas Mollusca were the second most important food in the gullet (31%). Relatively high volumes of the Amphipoda Caprella sp. (skeleton shrimp) and the Decopoda Crangon septemspinosa (Sand Shrimp) were recorded in the gullet and gizzard. Ensis directus (Atlantic Jackknife Clam) formed the greatest volume of Mollusca in the gizzard (15%) and in the gullet (15%). Long-tailed Ducks had fed on this Bivalvia and several other species of Mollusca that had no shell or broken shell when consumed. Many of the food organisms were apparently dislodged and some damaged by the clamming operation creating an opportunistic feeding strategy for the Long-tailed Ducks.

  11. Bioassay of Lake Onego bottom sediments toxicity based on their chemical composition and deepwater macrozoobenthos state

    Directory of Open Access Journals (Sweden)

    Kalinkina Nataliya Michailovna

    2017-03-01

    Full Text Available The bioassay of the toxicity of bottom sediments sampled in different areas of Lake Onega was carried out by crustaceans biotesting (Ceriodaphnia affinis Lillijeborg. It was shown that in the most areas of Lake Onega there are non-toxic bottom sediments. Toxic bottom sediments were found in Kondopogskaya Bay, intensively polluted with pulp-and-paper mill wastewaters. For the first time in the deep central part of Lake Onega the area was revealed where the toxic bottom sediments contain a high content of iron, manganese and other trace elements typical for the central areas of the lake. The mapping of the bottom of Lake Onega was accomplished, and three zones were identified based on the analysis of the data concerning the chemical composition of bottom sediments, bioassay toxicity data and the results of the deepwater macrozoobenthos assessment. For each zone the parameters of the main groups of benthos (Amphipoda, Oligochaeta, Chironomidae were defined. The first zone is located in the area of intensive anthropogenic influence (Kondopogskaya Bay, Petrozavodskaya Bay, Povenets Bay, Kizhi Skerries. The second zone is located mostly in the deep part of Petrozavodskaya Bay, where the most intensive development of amphipods is observed. The third area is identified for the first time: it is located in the central deep part of Lake Onega, where the communities of macrozoobenthos are limited by a natural toxic factor.

  12. Field Validation of Toxicity Tests to Evaluate the Potential for Beneficial Use of Produced Water

    Energy Technology Data Exchange (ETDEWEB)

    Joseph Bidwell; Jonathan Fisher; Naomi Cooper

    2008-03-31

    This study investigated potential biological effects of produced water contamination derived from occasional surface overflow and possible subsurface intrusion at an oil production site along the shore of Skiatook Lake, Oklahoma. We monitored basic chemistry and acute toxicity to a suite of standard aquatic test species (fathead minnow-Pimephales promelas, Daphnia pulex, Daphnia magna, and Ceriodaphnia dubia) in produced water and in samples taken from shallow groundwater wells on the site. Toxicity identification evaluations and ion toxicity modeling were used to identify toxic constituents in the samples. Lake sediment at the oil production site and at a reference site were also analyzed for brine intrusion chemically and by testing sediment toxicity using the benthic invertebrates, Chironomus dilutus, and Hyallela azteca. Sediment quality was also assessed with in situ survival and growth studies with H. azteca and the Asian clam, Corbicula fluminea, and by benthic macroinvertebrate community sampling. The produced water was acutely toxic to the aquatic test organisms at concentrations ranging from 1% to 10% of the whole produced water sample. Toxicity identification evaluation and ion toxicity modeling indicated major ion salts and hydrocarbons were the primary mixture toxicants. The standardized test species used in the laboratory bioassays exhibited differences in sensitivity to these two general classes of contaminants, which underscores the importance of using multiple species when evaluating produced water toxicity. Toxicity of groundwater was greater in samples from wells near a produced water injection well and an evaporation pond. Principle component analyses (PCA) of chemical data derived from the groundwater wells indicated dilution by lake water and possible biogeochemical reactions as factors that ameliorated groundwater toxicity. Elevated concentrations of major ions were found in pore water from lake sediments, but toxicity from these ions was

  13. Composition, abundance and distribution of macrozooplankton in Culebra Bay, Gulf of Papagayo, Pacific coast of Costa Rica and its value as bioindicator of pollution

    Directory of Open Access Journals (Sweden)

    Melinda Bednarski

    2004-12-01

    Full Text Available The abundance, distribution and composition of the macrozooplankton of Culebra Bay, Costa Rica (10º 38’ N - 85º 40’ W were studied at four stations throughout the dry (February - May and rainy (September - November seasons of 2000. The samples were collected at two-week intervals using a 500µm mesh net with a 0.5 m diameter opening. Copepods (23-31% and ostracods (20-34% were predominant throughout the year, followed by cladocerans (2.5-14%, zoea (6.6-9.5%, and siphonophores (2.5-7.2%. High densities of zooplankton were obtained in February and March with peak abundance on March 18. The lowest densities were observed on September 3 and November 5. Significant differences in abundances at each station were observed for the groups Acartia tonsa (Copepoda, Ctenophora, Medusae, Ostracoda, Zoea, and Amphipoda. Comparison of the dry and rainy seasons revealed significantly higher zooplankton abundance in the dry season and copepod domination of all stations; during the rainy season ostracods dominated the off-shore areas. Zooplankton abundance and distribution are influenced by upwelling, which occurs during the dry season in Culebra BayLa abundancia, distribución y composición del macrozooplancton fue estudiada en bahía Culebra Costa Rica (10º 38’ N and 85º 40’ W en cuatro estaciones durante la época seca (Febrero-Mayo y lluviosa (Setiembre - Noviembre del año 2000. Las muestras fueron colectadas en intervalos de dos semanas usando una red de 500µm de poro y 0.50-m de diámetro. Copépodos (23-31% y ostrácodos (20-34% fueron predominantes através del año, seguidos por los cladóceros (2.5-14%, zoea (6.6-9.5%, y sifonóforos (2.5-7.2%. Altas densidades de zooplancton fueron obtenidas en Febrero y Marzo, con un pico el 18 de Marzo. Las más bajas densidades fueron observadas el 3 de Septiembre y 5 de Noviembre. Se observaron diferencias significativas en las abundancias en cada estación para los copépodos de la especie Acartia

  14. Natural disturbance shapes benthic intertidal macroinvertebrate communities of high latitude river deltas

    Science.gov (United States)

    Churchwell, Roy T.; Kendall, Steve J.; Blanchard, Amy L.; Dunton, Kenneth H.; Powell, Abby N.

    2016-01-01

    Unlike lower latitude coastlines, the estuarine nearshore zones of the Alaskan Beaufort Sea are icebound and frozen up to 9 months annually. This annual freezing event represents a dramatic physical disturbance to fauna living within intertidal sediments. The main objectives of this study were to describe the benthic communities of Beaufort Sea deltas, including temporal changes and trophic structure. Understanding benthic invertebrate communities provided a baseline for concurrent research on shorebird foraging ecology at these sites. We found that despite continuous year-to-year episodes of annual freezing, these estuarine deltas are populated by a range of invertebrates that represent both marine and freshwater assemblages. Freshwater organisms like Diptera and Oligochaeta not only survive this extreme event, but a marine invasion of infaunal organisms such as Amphipoda and Polychaeta rapidly recolonizes the delta mudflats following ice ablation. These delta sediments of sand, silt, and clay are fine in structure compared to sediments of other Beaufort Sea coastal intertidal habitats. The relatively depauperate invertebrate community that ultimately develops is composed of marine and freshwater benthic invertebrates. The composition of the infauna also reflects two strategies that make life on Beaufort Sea deltas possible: a migration of marine organisms from deeper lagoons to the intertidal and freshwater biota that survive the 9-month ice-covered period in frozen sediments. Stable isotopic analyses reveal that both infaunal assemblages assimilate marine and terrestrial sources of organic carbon. These results provide some of the first quantitative information on the infaunal food resources of shallow arctic estuarine systems and the long-term persistence of these invertebrate assemblages. Our data help explain the presence of large numbers of shorebirds in these habitats during the brief summer open-water period and their trophic importance to migrating

  15. Influence of Benthic Macrofauna as a Spatial Structuring Agent for Juvenile Haddock (Melanogrammus aeglefinus) on the Eastern Scotian Shelf, Atlantic Canada.

    Science.gov (United States)

    Rincón, Beatriz; Kenchington, Ellen L

    2016-01-01

    We examined the habitat of juvenile haddock on the eastern Scotian Shelf (off Nova Scotia, Canada) in relation to grab-sampled benthic macrofaunal invertebrate species assemblages in order to determine whether there were significant differences in benthic macrofauna between areas of historically persistent high and low juvenile haddock abundance. Our analyses were conducted over two spatial scales in each of two years: among banks (Emerald, Western and Sable Island), approximately 60 km distant from each other, and between areas of high and low juvenile haddock abundance at distances of 10 to 30 km-all in an area that had not experienced groundfishing in the decade prior to sampling. We also examined fine-scale (10s of metres) within-site variability in the macrofauna and used surficial sediment characteristics, along with hydrographic variables, to identify environmental correlates. PERMANOVA identified statistically significant differences in biomass, density and composition of the benthos associated with juvenile haddock abundance; however it was difficult to determine whether the results had biological relevance. Post hoc tests showed that these differences occurred only on Sable Island Bank where both fish and benthos may have been independently responding to sediment type which was most different there (100% sand in the area of low haddock abundance vs. 22% gravel in the area of high haddock abundance). In total, 383 benthic taxa representing 13 phyla were identified. Annelida was the most specious phylum (36.29% of taxa, representing 33 families), followed by Arthropoda (with Crustaceans, mostly Amphipoda, accounting for 25.07% of the total number of taxa). The strongest pattern in the macrofauna was expressed at the largest scale, between banks, accounting for approximately 25% of the variation in the data. Emerald Bank, deeper, warmer and saltier than the Western and Sable Island Banks, had a distinctive fauna.

  16. Influence of Benthic Macrofauna as a Spatial Structuring Agent for Juvenile Haddock (Melanogrammus aeglefinus) on the Eastern Scotian Shelf, Atlantic Canada

    Science.gov (United States)

    2016-01-01

    We examined the habitat of juvenile haddock on the eastern Scotian Shelf (off Nova Scotia, Canada) in relation to grab-sampled benthic macrofaunal invertebrate species assemblages in order to determine whether there were significant differences in benthic macrofauna between areas of historically persistent high and low juvenile haddock abundance. Our analyses were conducted over two spatial scales in each of two years: among banks (Emerald, Western and Sable Island), approximately 60 km distant from each other, and between areas of high and low juvenile haddock abundance at distances of 10 to 30 km–all in an area that had not experienced groundfishing in the decade prior to sampling. We also examined fine-scale (10s of metres) within-site variability in the macrofauna and used surficial sediment characteristics, along with hydrographic variables, to identify environmental correlates. PERMANOVA identified statistically significant differences in biomass, density and composition of the benthos associated with juvenile haddock abundance; however it was difficult to determine whether the results had biological relevance. Post hoc tests showed that these differences occurred only on Sable Island Bank where both fish and benthos may have been independently responding to sediment type which was most different there (100% sand in the area of low haddock abundance vs. 22% gravel in the area of high haddock abundance). In total, 383 benthic taxa representing 13 phyla were identified. Annelida was the most specious phylum (36.29% of taxa, representing 33 families), followed by Arthropoda (with Crustaceans, mostly Amphipoda, accounting for 25.07% of the total number of taxa). The strongest pattern in the macrofauna was expressed at the largest scale, between banks, accounting for approximately 25% of the variation in the data. Emerald Bank, deeper, warmer and saltier than the Western and Sable Island Banks, had a distinctive fauna. PMID:27649419

  17. Annotated list of marine alien species in the Mediterranean with records of the worst invasive species

    Directory of Open Access Journals (Sweden)

    A. ZENETOS

    2005-12-01

    Full Text Available This collaborative effort by many specialists across the Mediterranean presents an updated annotated list of alien marine species in the Mediterranean Sea. Alien species have been grouped into six broad categories namely established, casual, questionable, cryptogenic, excluded and invasive, and presented in lists of major ecofunctional/taxonomic groups. The establishment success within each group is provided while the questionable and excluded records are commented in brief. A total of 963 alien species have been reported from the Mediterranean until December 2005, 218 of which have been classified as excluded (23% leaving 745 of the recorded species as valid aliens. Of these 385 (52% are already well established, 262 (35% are casual records, while 98 species (13% remain “questionable” records. The species cited in this work belong mostly to zoobenthos and in particular to Mollusca and Crustacea, while Fish and Phytobenthos are the next two groups which prevail among alien biota in the Mediterranean. The available information depends greatly on the taxonomic group examined. Thus, besides the three groups explicitly addressed in the CIESM atlas series (Fish, Decapoda/Crustacea and Mollusca, which are however updated in the present work, Polychaeta, Phytobenthos, Phytoplankton and Zooplankton are also addressed in this study. Among other zoobenthic taxa sufficiently covered in this study are Echinodermata, Sipuncula, Bryozoa and Ascidiacea. On the contrary, taxa such as Foraminifera, Amphipoda and Isopoda, that are not well studied in the Mediterranean, are insufficiently covered. A gap of knowledge is also noticed in Parasites, which, although ubiquitous and pervasive in marine systems, have been relatively unexplored as to their role in marine invasions. Conclusively the lack of funding purely systematic studies in the region has led to underestimation of the number of aliens in the Mediterranean. Emphasis is put on those species that are

  18. Macro-invertebrate decline in surface water polluted with imidacloprid.

    Directory of Open Access Journals (Sweden)

    Tessa C Van Dijk

    Full Text Available Imidacloprid is one of the most widely used insecticides in the world. Its concentration in surface water exceeds the water quality norms in many parts of the Netherlands. Several studies have demonstrated harmful effects of this neonicotinoid to a wide range of non-target species. Therefore we expected that surface water pollution with imidacloprid would negatively impact aquatic ecosystems. Availability of extensive monitoring data on the abundance of aquatic macro-invertebrate species, and on imidacloprid concentrations in surface water in the Netherlands enabled us to test this hypothesis. Our regression analysis showed a significant negative relationship (P<0.001 between macro-invertebrate abundance and imidacloprid concentration for all species pooled. A significant negative relationship was also found for the orders Amphipoda, Basommatophora, Diptera, Ephemeroptera and Isopoda, and for several species separately. The order Odonata had a negative relationship very close to the significance threshold of 0.05 (P = 0.051. However, in accordance with previous research, a positive relationship was found for the order Actinedida. We used the monitoring field data to test whether the existing three water quality norms for imidacloprid in the Netherlands are protective in real conditions. Our data show that macrofauna abundance drops sharply between 13 and 67 ng l(-1. For aquatic ecosystem protection, two of the norms are not protective at all while the strictest norm of 13 ng l(-1 (MTR seems somewhat protective. In addition to the existing experimental evidence on the negative effects of imidacloprid on invertebrate life, our study, based on data from large-scale field monitoring during multiple years, shows that serious concern about the far-reaching consequences of the abundant use of imidacloprid for aquatic ecosystems is justified.

  19. Efeito de fatores bióticos no crescimento de Hypnea musciformis(Rhodophyta - Gigartinales

    Directory of Open Access Journals (Sweden)

    Reis Renata Perpetuo

    2003-01-01

    Full Text Available O melhor conhecimento da ação de fatores biológicos sobre o crescimento de Hypnea musciformis (Wulfen in Jacqu. J. V. Lamour. torna-se um aspecto premente visando a otimização do manejo e a conservação dessa espécie de interesse comercial. Uma vez que as espécies de Sargassum C. Agardh são consideradas importantes substratos para a fixação de H. musciformis, durante 18 meses, foram realizadas amostragens do tipo destrutiva, em uma população natural de H. musciformis epífita sobre Sargassum spp., em três profundidades de um costão rochoso no Rio de Janeiro. Obteve-se relação positiva entre as biomassas de ambos os gêneros, além da preferência destes pelo ambiente sublitorâneo. Visto a usual presença de mesoherbívoros (Amphipoda nos talos dessas algas, a ação da herbivoria em H. musciformis e S. cymosum var. nanum foi testada em experimento in vitro. A herbivoria foi confirmada para ambos os táxons e a maior taxa de crescimento de H. musciformis favoreceu o crescimento de S. cymosum var.nanum, diminuindo o ataque de mesoherbívoros por ser alimento disponível. Observou-se também que não houve inibição do crescimento de H. musciformis por S. cymosum var.nanum. Sendo assim, recomenda-se que a colheita de H. musciformis para fins comerciais em bancos naturais de Sargassum spp. seja manejada para não causar danos às comunidades marinhas bentônicas.

  20. Phylogeny as a proxy for ecology in seagrass amphipods: which traits are most conserved?

    Directory of Open Access Journals (Sweden)

    Rebecca J Best

    Full Text Available Increasingly, studies of community assembly and ecosystem function combine trait data and phylogenetic relationships to gain novel insight into the ecological and evolutionary constraints on community dynamics. However, the key to interpreting these two types of information is an understanding of the extent to which traits are phylogenetically conserved. In this study, we develop the necessary framework for community phylogenetics approaches in a system of marine crustacean herbivores that play an important role in the ecosystem functioning of seagrass systems worldwide. For 16 species of amphipods and isopods, we (1 reconstructed phylogenetic relationships using COI, 16S, and 18S sequences and Bayesian analyses, (2 measured traits that are potentially important for assembling species between and within habitats, and (3 compared the degree to which each of these traits are evolutionarily conserved. Despite poor phylogenetic resolution for the order Amphipoda as a whole, we resolved almost all of the topology for the species in our system, and used a sampling of ultrametric trees from the posterior distribution to account for remaining uncertainty in topology and branch lengths. We found that traits varied widely in their degree of phylogenetic signal. Body mass, fecundity, and tube building showed very strong phylogenetic signal, and temperature tolerance and feeding traits showed much less. As such, the degree of signal was not predictable based on whether the trait is related to environmental filtering or to resource partitioning. Further, we found that even with strong phylogenetic signal in body size, (which may have large impacts on ecosystem function, the predictive relationship between phylogenetic diversity and ecosystem function is not straightforward. We show that patterns of phylogenetic diversity in communities of seagrass mesograzers could lead to a variety of interpretations and predictions, and that detailed study of trait

  1. Temporal and spatial distribution of the meiobenthic community in Daya Bay, South China Sea

    Science.gov (United States)

    Tang, L.; Li, H. X.; Yan, Y.

    2012-04-01

    Spatial and temporal biodiversity patterns of the meiobenthos were studied for the first time in Daya Bay, which is a tropical semi-enclosed basin located in the South China Sea. The abundance, biomass, and composition of the meiobenthos and the basic environmental factors in the bay were investigated. The following 19 taxonomic groups were represented in the meiofauna: Nematoda, Copepoda, Polychaeta, Oligochaeta, Kinorhyncha, Gastrotricha, Ostracoda, Bivalvia, Turbellaria, Nemertinea, Sipuncula, Hydroida, Amphipoda, Cumacea, Halacaroidea, Priapulida, Echinodermata, Tanaidacea, and Rotifera. Total abundance and biomass of the meiobenthos showed great spatial and temporal variation, with mean values of 993.57 ± 455.36 ind cm-2 and 690.51 ± 210.64 μg 10 cm-2, respectively. Nematodes constituted 95.60 % of the total abundance and thus had the greatest effect on meiofauna quantity and distribution, followed by copepods (1.55 %) and polychaetes (1.39 %). Meiobenthos abundance was significantly negatively correlated with water depth at stations (r=-0.747, P<0.05) and significantly negatively correlated with silt-clay content (r=-0.516, P<0.01) and medium diameter (r=-0.499, P<0.01) of the sediment. Similar results were found for correlations of biomass and abundance of nematodes with environmental parameters. Polychaete abundance was positively correlated with the bottom water temperature (r=0.456, P<0.01). Meiobenthos abundance differed significantly among seasons (P<0.05), although no significant difference among stations and the interaction of station × season was detected by two-way ANOVA. In terms of vertical distribution, most of the meiobenthos was found in the surface layer of sediment. This pattern was apparent for nematodes and copepods, but a vertical distribution pattern for polychaetes was not as obvious. Based on the biotic indices and analyses of their correlations and variance, the diversity of this community was likely to be influenced by

  2. Fungal composition on leaves explains pollutant-mediated indirect effects on amphipod feeding.

    Science.gov (United States)

    Bundschuh, Mirco; Zubrod, Jochen P; Kosol, Sujitra; Maltby, Lorraine; Stang, Christoph; Duester, Lars; Schulz, Ralf

    2011-07-01

    The energy stored in coarse particulate organic matter, e.g. leaf litter, is released to aquatic ecosystems by breakdown processes involving microorganisms and leaf shredding invertebrates. The palatability of leaves and thus the feeding of shredders on leaf material are highly influenced by microorganisms. However, implications in the colonization of leaves by microorganisms (=conditioning) caused by chemical stressors are rarely studied. Our laboratory experiments, therefore, investigated for the first time effects of a fungicide on the conditioning process of leaf material by means of food-choice experiments using Gammarus fossarum (Crustacea: Amphipoda). Additionally, microbial analyses were conducted to facilitate the mechanistic understanding of the observed behavior. Gammarids significantly preferred control leaf discs over those conditioned in presence of the fungicide tebuconazole at concentrations of 50 and 500 μg/L. Besides the decrease of fungal biomass with increasing fungicide concentration, also the leaf associated fungal community composition showed that species preferred by gammarids, such as Alatospora acumunata, Clavariopsis aquatica, or Flagellospora curvula, were more frequent in the control. Tetracladium marchalianum, however, which is rejected by gammarids, was abundant in all treatments suggesting an increasing importance of this species for the lower leaf palatability--as other more palatable fungal species were almost absent--in the fungicide treatments. Hence, the food-choice behavior of G. fossarum seems to be a suitable indicator for alterations in leaf associated microbial communities, especially fungal species composition, caused by chemical stressors. Finally, this or similar test systems may be a reasonable supplement to the environmental risk assessment of chemicals in order to achieve its protection goals, as on the one hand, indirect effects may occur far below concentrations known to affect gammarids directly, and on the other

  3. Macro-Invertebrate Decline in Surface Water Polluted with Imidacloprid

    Science.gov (United States)

    Van Dijk, Tessa C.; Van Staalduinen, Marja A.; Van der Sluijs, Jeroen P.

    2013-01-01

    Imidacloprid is one of the most widely used insecticides in the world. Its concentration in surface water exceeds the water quality norms in many parts of the Netherlands. Several studies have demonstrated harmful effects of this neonicotinoid to a wide range of non-target species. Therefore we expected that surface water pollution with imidacloprid would negatively impact aquatic ecosystems. Availability of extensive monitoring data on the abundance of aquatic macro-invertebrate species, and on imidacloprid concentrations in surface water in the Netherlands enabled us to test this hypothesis. Our regression analysis showed a significant negative relationship (Pmacro-invertebrate abundance and imidacloprid concentration for all species pooled. A significant negative relationship was also found for the orders Amphipoda, Basommatophora, Diptera, Ephemeroptera and Isopoda, and for several species separately. The order Odonata had a negative relationship very close to the significance threshold of 0.05 (P = 0.051). However, in accordance with previous research, a positive relationship was found for the order Actinedida. We used the monitoring field data to test whether the existing three water quality norms for imidacloprid in the Netherlands are protective in real conditions. Our data show that macrofauna abundance drops sharply between 13 and 67 ng l−1. For aquatic ecosystem protection, two of the norms are not protective at all while the strictest norm of 13 ng l−1 (MTR) seems somewhat protective. In addition to the existing experimental evidence on the negative effects of imidacloprid on invertebrate life, our study, based on data from large-scale field monitoring during multiple years, shows that serious concern about the far-reaching consequences of the abundant use of imidacloprid for aquatic ecosystems is justified. PMID:23650513

  4. Ocean acidification alters zooplankton communities and increases top-down pressure of a cubozoan predator.

    Science.gov (United States)

    Hammill, Edd; Johnson, Ellery; Atwood, Trisha B; Harianto, Januar; Hinchliffe, Charles; Calosi, Piero; Byrne, Maria

    2018-01-01

    The composition of local ecological communities is determined by the members of the regional community that are able to survive the abiotic and biotic conditions of a local ecosystem. Anthropogenic activities since the industrial revolution have increased atmospheric CO 2 concentrations, which have in turn decreased ocean pH and altered carbonate ion concentrations: so called ocean acidification (OA). Single-species experiments have shown how OA can dramatically affect zooplankton development, physiology and skeletal mineralization status, potentially reducing their defensive function and altering their predatory and antipredatory behaviors. This means that increased OA may indirectly alter the biotic conditions by modifying trophic interactions. We investigated how OA affects the impact of a cubozoan predator on their zooplankton prey, predominantly Copepoda, Pleocyemata, Dendrobranchiata, and Amphipoda. Experimental conditions were set at either current (pCO 2 370 μatm) or end-of-the-century OA (pCO 2 1,100 μatm) scenarios, crossed in an orthogonal experimental design with the presence/absence of the cubozoan predator Carybdea rastoni. The combined effects of exposure to OA and predation by C. rastoni caused greater shifts in community structure, and greater reductions in the abundance of key taxa than would be predicted from combining the effect of each stressor in isolation. Specifically, we show that in the combined presence of OA and a cubozoan predator, populations of the most abundant member of the zooplankton community (calanoid copepods) were reduced 27% more than it would be predicted based on the effects of these stressors in isolation, suggesting that OA increases the susceptibility of plankton to predation. Our results indicate that the ecological consequences of OA may be greater than predicted from single-species experiments, and highlight the need to understand future marine global change from a community perspective. © 2017 John Wiley & Sons

  5. Diet and food consumption of the pearl cichlid Geophagus brasiliensis (Teleostei: Cichlidae: relationships with gender and sexual maturity

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    Rodrigo F. Bastos

    Full Text Available Despite the importance of the pearl cichlid Geophagus brasiliensis for the aquarium fish trade worldwide and its wide distribution, many aspects of its biology, such as the relationships between its feeding ecology and reproductive behavior, are not fully understood in natural conditions on its native habitat. In this paper, we investigated its diet focusing on how differences in diet and food consumption are related to differences in gender and sexual maturity. The digestive tract of each individual was dissected and had its content analyzed, whereas each gonad was microscopically analyzed to determine gender (male/female and sexual maturity (immature/mature. A total of 28 females and 31 males were analyzed. Mature individuals were more common than immature specimens both for males (64.50% and females (64.30%. The analysis of 52 individuals with non-empty digestive tracts revealed a diet comprised of 27 items. According to the Index of Alimentary importance (%IAi, the most important food items in the diet were Gastropoda (37.30%, fragments of vascular plants (15.16%, detritus (10.14%, Amphipoda (9.24%, and fish scales (6.29%. Mature males had more empty stomachs (65.00% when compared to immature males (27.27% and immature (55.56% and mature females (40.00%. Also, mature females seemed to have more food consumption (greater mean values of total volume in their digestive tracts than mature males. Some hypotheses are proposed in order to distinguish if this gender-based difference in food consumption in mature individuals of the pearl cichlid could be associated with the development of primary and secondary sexual characteristics or with asymmetrical time invested in parental care activities.

  6. Comparative analyses of olfactory systems in terrestrial crabs (Brachyura: evidence for aerial olfaction?

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    Jakob Krieger

    2015-12-01

    Full Text Available Adaptations to a terrestrial lifestyle occurred convergently multiple times during the evolution of the arthropods. This holds also true for the “true crabs” (Brachyura, a taxon that includes several lineages that invaded land independently. During an evolutionary transition from sea to land, animals have to develop a variety of physiological and anatomical adaptations to a terrestrial life style related to respiration, reproduction, development, circulation, ion and water balance. In addition, sensory systems that function in air instead of in water are essential for an animal’s life on land. Besides vision and mechanosensory systems, on land, the chemical senses have to be modified substantially in comparison to their function in water. Among arthropods, insects are the most successful ones to evolve aerial olfaction. Various aspects of terrestrial adaptation have also been analyzed in those crustacean lineages that evolved terrestrial representatives including the taxa Anomala, Brachyura, Amphipoda, and Isopoda. We are interested in how the chemical senses of terrestrial crustaceans are modified to function in air. Therefore, in this study, we analyzed the brains and more specifically the structure of the olfactory system of representatives of brachyuran crabs that display different degrees of terrestriality, from exclusively marine to mainly terrestrial. The methods we used included immunohistochemistry, detection of autofluorescence- and confocal microscopy, as well as three-dimensional reconstruction and morphometry. Our comparative approach shows that both the peripheral and central olfactory pathways are reduced in terrestrial members in comparison to their marine relatives, suggesting a limited function of their olfactory system on land. We conclude that for arthropod lineages that invaded land, evolving aerial olfaction is no trivial task.

  7. Taxocoenosis and distribution of nektonic fauna in the rice fields of Kashmir (J and K) India.

    Science.gov (United States)

    Bahaar, S W N; Bhat, G A

    2011-04-15

    Present study attempts to identify the taxocoenosis and distribution of nektonic fauna harbouring the rice field ecosystems of Kashmir. The main objective of the study was to provide an overview of the nektonic community composition and physicochemical characteristics of flood waters. 6 sites were selected in Kupwara, Bandipora, Budgam, Srinagar, Pulwama and Anantnag districts of valley Kashmir. A total of 26 taxa belonging to 13 different orders were reported during the study which commenced through 2 consecutive crop cycles. The taxocoenosis was dominated by Coleoptera (10 taxa) followed by Hemiptera (3 taxa), Diptera (2 taxa), Diplostraca (2 taxa), Acarina, Anostraca, Anura, Amphipoda, Basommatophora, Cypriniformes, Cyprinodontiformes, Odonata and Pulmonata (1 taxa each). Diversity was calculated using Simpsons Index (D), Simpsons Index of Diversity (1-D), Simpsons Reciprocal Index (1/D), Shannon-Weiner Index (H'), Margalef Richness Index (d) and Evenness Index (e). Kupwara (34 degrees 02'N; 74 degrees 16'E) formed the most diverse site registering a total of 2384 individuals belonging to 24 taxa. A perusal of the primary data related to the physicochemical attributes of flood waters exhibited that average water temperature varied between 19-30 degrees C, average air temperature varied between 21 and 33 degrees C. pH depicted a variation between 6.0 and 9.0, Dissolved Oxygen varied between a minimum of 1.0 mg L(-1) and a maximum of 10 mg L(-1). Free CO2 ranged between 0 mg L(-1) and 6.1 mg(-1). The results pressed the need for recognizing and preserving rice fields as potential habitats for organisms that have successfully adapted to the highly manipulated and eutrophic conditions of rice paddies.

  8. Differential tolerance of two Gammarus pulex populations transplanted from different metallogenic regions to a polymetal gradient.

    Science.gov (United States)

    Khan, Farhan R; Irving, Jennifer R; Bury, Nicolas R; Hogstrand, Christer

    2011-03-01

    The River Hayle, Cornwall, UK exhibits pronounced Cu and Zn concentration gradients which were used to compare the metal handling abilities of two populations of Gammarus pulex (Crustacea: Amphipoda). One population was native to the Hayle region (Drym) and presumably has been historically impacted by elevated Cu and Zn levels, whilst naïve gammarids were collected from the River Cray, Kent, UK. Both populations were subject to a 32 day in situ exposure at four R. Hayle sites (Drym, Godolphin, Relubbus and St. Erth). Mortality (LT50), Cu and Zn accumulation and sub-cellular distribution, and oxidative stress (malondialdehyde production) increased with the expected Cu and Zn bioavailabilities at the four sites (i.e. Godolphin>Relubbus>St. Erth>Drym). The naïve population experienced greater metal induced effects in terms of Cu and Zn accumulation, oxidative stress responses and lower LT50s. Analysis of Cu and Zn sub-cellular distribution, however, revealed no significant differences in metal handling. In both populations each metal was localised predominantly to the sub-cellular fraction containing metal bound to metallothionein-like proteins (MTLP) or that holding both metal-rich granules (MRG) and exoskeleton, MTLP and MRG binding being indicative of metal detoxification. However, a greater capacity for detoxified metal storage is not a mechanism implicated in the perceived tolerance of the historically impacted gammarids. Instead our results suggest that the historically impacted population was adapted for lower uptake of Cu and Zn leading to lower bioaccumulation, stress response and ultimately mortality. These results demonstrate not only the usefulness of the in situ methodology, but also that differences in population exposure history can cause significant differences in metal responses during exposure at higher concentrations. Copyright © 2011 Elsevier B.V. All rights reserved.

  9. Threads of continuity and change. Fabricating unity in anthropology

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    Brumfiel, Elizabeth M.

    2007-12-01

    Full Text Available In this article, I compare backstrap-loom weaving in three cultural contexts: the ancient Maya, the ancient Aztecs, and 20th century Mesoamerica. Although continuities are present, important differences exist in the ways that weaving was situated historically. Among the Classic Maya, weaving defined class; in Aztec Mexico, weaving defined gender; and in 20th-century Mesoamerica, weaving defined ethnicity. A comparison of these cases suggests that historical study is a useful tool for both archaeologists and ethnographers. It promotes recognition of the diversity of practice and belief in ancient societies. It helps to define the scope of contemporary ethnographic study. It combats cultural essentialism and injects agency into our accounts. It enables us to acknowledge both the rich heritage of indigenous peoples and the fact of culture change. Comparative historical study provides a strong rationale for the continued association of archaeology and cultural anthropology as parts of a wider anthropological whole.

    En este artículo comparo el proceso de tejido en telares de cintura de tres contextos culturales: los Maya, los antiguos aztecas y la Mesoamérica del siglo XX. Aunque existen evidentes continuidades, también hay importantes diferencias en sus contextos históricos. En el Maya Clásico el tejido marcó la clase social, el género entre los Azteca de México y el origen étnico en la Mesoamérica del siglo XX. El análisis comparativo de estos casos históricos sugiere que la comparación es una herramienta útil tanto para arqueólogos como para los etnógrafos: promueve el reconocimiento de la diversidad de las prácticas y las creencias de las sociedades antiguas; contribuye a definir el alcance del estudio etnográfico contemporáneo; combate el esencialismo cultural y carga a nuestras narrativas de capacidad transformadora; nos permite reconocer el rico patrimonio de los pueblos indígenas y el hecho cultural del cambio. El

  10. Linking in situ bioassays and population dynamics of macroinvertebrates to assess agricultural contamination in streams of the Argentine pampa.

    Science.gov (United States)

    Jergentz, S; Pessacq, P; Mugni, H; Bonetto, C; Schulz, R

    2004-10-01

    The two local crustacean species Hyalella curvispina and Macrobrachium borelli were chosen for assessment of agricultural contamination in two streams (Horqueta and Maguire) in the Argentine pampa. In parallel with in situ bioassays of both species, the population dynamics and the organismic drift of H. curvispina were investigated throughout the main period of insecticide application, from December 2001 to March 2002. In Maguire none of the current-use insecticides (chlorpyrifos, alpha-cypermethrin, and endosulfan) in question were detected throughout the sampling period. During 1-week intervals with no contamination by insecticides the survival rate of H. curvispina varied between 77 +/- 6% (+/- SE, n = 4) and 85 +/- 3%. In Horqueta during a week with a peak insecticide contamination of 64 microg/kg chlorpyrifos in the suspended particles, a mortality of 100% was observed in the in situ bioassays for both species, H. curvispina and M. borelli. At the same time, in Maguire H. curvispina showed reduced survival rates of 23 +/- 5% and 25 +/- 18% at the two sites, while the survival rate of M. borelli was 60 +/- 11% upstream and 93 +/- 5% downstream, below a wetland. During the period with 100% mortality of H. curvispina in Horqueta, the population density of this species decreased correspondingly, from 106 +/- 26 to 0 individuals/m(2). We conclude that in situ bioassays can be successfully linked to in-stream population dynamics for the same species and that this link is very useful for interpreting causal exposure-effect relationships.

  11. Bioavailability, ecotoxicity, and geological characteristics of trace lead in sediments from two sites on Negro River, Uruguay, South America.

    Science.gov (United States)

    Míguez, Diana M; Huertas, Raquel; Carrara, María V; Carnikián, Agustín; Bouvier, María E; Martínez, María J; Keel, Karen; Pioda, Carolina; Darré, Elena; Pérez, Ramiro; Viera, Santiago; Massa, Enrique

    2012-04-01

    Bioassays of two sites along the Rio Negro in Uruguay indicate ecotoxicity, which could be attributable to trace concentrations of lead in river sediments. Monthly samples at two sites at Baygorria and Bonete locations were analyzed for both particle size and lead. Lead was determined by atomic spectrometry in river water and sediment and particle size by sieving and sedimentation. Data showed that Baygorria's sediments have greater percentage of clay than Bonete's (20.4 and 5.8%, respectively). Lead was measurable in Baygorria's sediments, meanwhile in Bonete's, it was always below the detection limit. In water samples, lead was below detection limit at both sites. Bioassays using sub-lethal growth and survival test with Hyalella curvispina amphipod, screening with bioluminescent bacteria Photobacterium leiognathi, and acute toxicity bioassay with Pimephales promelas fish indicated toxicity at Baygorria, with much less effect at Bonete. Even though no lethal effects could be demonstrated, higher sub-lethal toxicity was found in samples from Baygorria site, showing a possible concentration of the contaminant in the clay fraction.

  12. Vascular epiphytes and host trees of ant-gardens in an anthropic landscape in southeastern Mexico

    Science.gov (United States)

    Morales-Linares, Jonas; García-Franco, José G.; Flores-Palacios, Alejandro; Valenzuela-González, Jorge E.; Mata-Rosas, Martín; Díaz-Castelazo, Cecilia

    2016-12-01

    Ant-gardens (AGs) are considered one of the most complex mutualist systems between ants and plants, since interactions involving dispersal, protection, and nutrition occur simultaneously in them; however, little is known about the effects of the transformation of ecosystems on their diversity and interactions. In five environments with different land use within an anthropic landscape in southeastern Mexico, we investigated the diversity and composition of epiphytes and host trees of AGs built by Azteca gnava. A total of 10,871 individuals of 26 epiphytic species, associating with 859 AGs located in 161 host trees, were recorded. The diversity and composition of epiphytes tended to be different between environments; however, Aechmea tillandsioides and Codonanthe uleana were the most important species and considered true AG epiphytes, because they were the most frequent, abundant, and occurred exclusively in AGs. Other important species were the orchids Epidendrum flexuosum, Coryanthes picturata, and Epidendrum pachyrachis, and should also be considered true AG epiphytes, because they occurred almost exclusively in the AGs. The AG abundance in agroforestry plantations was similar or even greater than in riparian vegetation (natural habitat). The AGs were registered in 37 host species but were more frequent in Mangifera indica and Citrus sinensis. We conclude that true epiphytes of A. gnava AGs persist in different environments and host trees, and even these AGs could proliferate in agroforestry plantations of anthropic landscapes.

  13. La cartografía como relato: intervenir los mapas, narrar las ciudades

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    Esperanza López Parada

    2013-11-01

    Full Text Available El misterio que rodea el mapa de la primera ciudad imperial azteca, publicado en la traducción latina de la Segunda Carta de Relación de Hernán Cortés –su origen, su orientación, su autoría, su sentido–, se ve acompañado por los cambios que, con un claro sesgo ideológico, introducen las reproducciones posteriores en las imprentas de toda Europa. Si no resultan menos enigmáticos los rasgos que, en cambio, permanecen inalterados, tampoco arrojan luz sus nuevos empleos, independizándose ya de la relación cortesiana para ilustrar más crónicas o completar la descripción de otras ciudades americanas. El estudio de la suerte de aquel plano de la ciudad conquistada, que algunos atribuyeron al propio Durero, tendrá que habérselas con el proceso complejísimo por el que una representación como la cartográfica –que se busca sea descriptiva, objetiva, exacta– alcanza en este caso los modos y maneras de una ficción o un espejismo, hasta dejar de funcionar como mapa únicamente para convertirse en un ramillete de relatos entrecruzados.

  14. El sacrificio gladiatorio y su vinculación con la guerra en la sociedad mexicana

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    Bueno Bravo, Isabel

    2009-12-01

    Full Text Available The following work analyzes how the Mexica State promoted the success of war through public ceremony and focuses on the celebration of Tlacaxipehualiztli. As was one of the most important ceremonies of the year, it was where the most powerful provincial leaders as well as millions of people from all corners of the Anahuac met. This was a favourable moment for the empire to display all of its propaganda and flaunt its power. It is the dark side of conquest, of blood and sand, or as paraphrased by Juvenal, panem et circus.

    El siguiente trabajo analiza cómo el Estado azteca-mexica rentabilizó el éxito de la guerra a través de las ceremonias públicas, centrándose en la fiesta de tlacaxipehualiztli, una de las más importantes del calendario, donde se daban cita los gobernantes de las provincias más poderosas, así como millones de personas venidas de todos los rincones del Anahuac. Este era el momento propicio para que el imperio desplegara toda su propaganda e hiciera ostentación de su poder. Era el lado oscuro de la conquista, sangre y arena o parafraseando a Juvenal panem et circenses.

  15. Las Ideas Psicológicas en Colombia

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    Rubén Ardila

    1999-06-01

    Full Text Available El interés en los problemas que hoy llamamos psicológicos se encuentra en todas las grandes civilizaciones. En América existieron importantes ideas psicológicas en los Mayas, Aztecas, Incas y en los pobladores de la actual Colombia. La psicología en su conceptualización moderna comienza en 1879 con la fundación del primer Laboratorio de Psicología Experimental en la Universidad de Leipzig por obra de W. Wundt. Hoy la psicología como disciplina es tanto una ciencia como una profesión, y tanto una ciencia natural como una ciencia social. En el contexto colombiano el origen está ligado a la fundación del Instituto de Psicología Aplicada de la Universidad Nacional de Colombia, el 20 de noviembre de 1947, con el cual comienzan los estudios profesionales de psicología en Colombia y en el resto de Latinoamérica. En este artículo se analiza el estado de la psicología como disciplina, como campo de investigación y como área de aplicación profesional. Se concluye que es necesario enfatizar más los aspectos científicos, además de los profesionales y trabajar en contextos multi e interdisciplinarios, con otros profesionales de las ciencias naturales y sociales.

  16. Harnessing ant defence at fruits reduces bruchid seed predation in a symbiotic ant–plant mutualism

    Science.gov (United States)

    Pringle, Elizabeth G.

    2014-01-01

    In horizontally transmitted mutualisms, mutualists disperse separately and reassemble in each generation with partners genetically unrelated to those in the previous generation. Because of this, there should be no selection on either partner to enhance the other's reproductive output directly. In symbiotic ant–plant mutualisms, myrmecophytic plants host defensive ant colonies, and ants defend the plants from herbivores. Plants and ants disperse separately, and, although ant defence can indirectly increase plant reproduction by reducing folivory, it is unclear whether ants can also directly increase plant reproduction by defending seeds. The neotropical tree Cordia alliodora hosts colonies of Azteca pittieri ants. The trees produce domatia where ants nest at stem nodes and also at the node between the peduncle and the rachides of the infloresence. Unlike the stem domatia, these reproductive domatia senesce after the tree fruits each year. In this study, I show that the tree's resident ant colony moves into these ephemeral reproductive domatia, where they tend honeydew-producing scale insects and patrol the nearby developing fruits. The presence of ants significantly reduced pre-dispersal seed predation by Amblycerus bruchid beetles, thereby directly increasing plant reproductive output. PMID:24807259

  17. Water stress strengthens mutualism among ants, trees, and scale insects.

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    Elizabeth G Pringle

    2013-11-01

    Full Text Available Abiotic environmental variables strongly affect the outcomes of species interactions. For example, mutualistic interactions between species are often stronger when resources are limited. The effect might be indirect: water stress on plants can lead to carbon stress, which could alter carbon-mediated plant mutualisms. In mutualistic ant-plant symbioses, plants host ant colonies that defend them against herbivores. Here we show that the partners' investments in a widespread ant-plant symbiosis increase with water stress across 26 sites along a Mesoamerican precipitation gradient. At lower precipitation levels, Cordia alliodora trees invest more carbon in Azteca ants via phloem-feeding scale insects that provide the ants with sugars, and the ants provide better defense of the carbon-producing leaves. Under water stress, the trees have smaller carbon pools. A model of the carbon trade-offs for the mutualistic partners shows that the observed strategies can arise from the carbon costs of rare but extreme events of herbivory in the rainy season. Thus, water limitation, together with the risk of herbivory, increases the strength of a carbon-based mutualism.

  18. Water Stress Strengthens Mutualism Among Ants, Trees, and Scale Insects

    Science.gov (United States)

    Pringle, Elizabeth G.; Akçay, Erol; Raab, Ted K.; Dirzo, Rodolfo; Gordon, Deborah M.

    2013-01-01

    Abiotic environmental variables strongly affect the outcomes of species interactions. For example, mutualistic interactions between species are often stronger when resources are limited. The effect might be indirect: water stress on plants can lead to carbon stress, which could alter carbon-mediated plant mutualisms. In mutualistic ant–plant symbioses, plants host ant colonies that defend them against herbivores. Here we show that the partners' investments in a widespread ant–plant symbiosis increase with water stress across 26 sites along a Mesoamerican precipitation gradient. At lower precipitation levels, Cordia alliodora trees invest more carbon in Azteca ants via phloem-feeding scale insects that provide the ants with sugars, and the ants provide better defense of the carbon-producing leaves. Under water stress, the trees have smaller carbon pools. A model of the carbon trade-offs for the mutualistic partners shows that the observed strategies can arise from the carbon costs of rare but extreme events of herbivory in the rainy season. Thus, water limitation, together with the risk of herbivory, increases the strength of a carbon-based mutualism. PMID:24223521

  19. Population responses to environmental change in a tropical ant: the interaction of spatial and temporal dynamics.

    Science.gov (United States)

    Jackson, Doug; Vandermeer, John; Perfecto, Ivette; Philpott, Stacy M

    2014-01-01

    Spatial structure can have a profound, but often underappreciated, effect on the temporal dynamics of ecosystems. Here we report on a counterintuitive increase in the population of a tree-nesting ant, Azteca sericeasur, in response to a drastic reduction in the number of potential nesting sites. This surprising result is comprehensible when viewed in the context of the self-organized spatial dynamics of the ants and their effect on the ants' dispersal-limited natural enemies. Approximately 30% of the trees in the study site, a coffee agroecosystem in southern Mexico, were pruned or felled over a two-year period, and yet the abundance of the ant nests more than doubled over the seven-year study. Throughout the transition, the spatial distribution of the ants maintained a power-law distribution - a signal of spatial self organization - but the local clustering of the nests was reduced post-pruning. A cellular automata model incorporating the changed spatial structure of the ants and the resulting partial escape from antagonists reproduced the observed increase in abundance, highlighting how self-organized spatial dynamics can profoundly influence the responses of ecosystems to perturbations.

  20. Population responses to environmental change in a tropical ant: the interaction of spatial and temporal dynamics.

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    Doug Jackson

    Full Text Available Spatial structure can have a profound, but often underappreciated, effect on the temporal dynamics of ecosystems. Here we report on a counterintuitive increase in the population of a tree-nesting ant, Azteca sericeasur, in response to a drastic reduction in the number of potential nesting sites. This surprising result is comprehensible when viewed in the context of the self-organized spatial dynamics of the ants and their effect on the ants' dispersal-limited natural enemies. Approximately 30% of the trees in the study site, a coffee agroecosystem in southern Mexico, were pruned or felled over a two-year period, and yet the abundance of the ant nests more than doubled over the seven-year study. Throughout the transition, the spatial distribution of the ants maintained a power-law distribution - a signal of spatial self organization - but the local clustering of the nests was reduced post-pruning. A cellular automata model incorporating the changed spatial structure of the ants and the resulting partial escape from antagonists reproduced the observed increase in abundance, highlighting how self-organized spatial dynamics can profoundly influence the responses of ecosystems to perturbations.

  1. Notes on the nesting biology of five species of Euglossini (Hymenoptera: Apidae in the Brazilian Amazon

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    Fernando Carvalho-Filho

    2017-04-01

    Resumo. As abelhas-da-orquídea (Euglossini possuem tamanho médio a grande, corpo parcialmente ou completamente metálico e são relativamente comuns na região Neotropical. Apesar disso, a biologia de nidificação da maioria das espécies permanece desconhecida. Portanto, o objetivo deste estudo e fornecer novas informações sobre a biologia de nidificação de cinco espécies de Euglossini encontradas em área urbana e florestada da Amazônia Brasileira. Os ninhos de Eufriesea pulchra (Smithe Euglossa chalybeata Frieseforam registrados pela primeira vez, encontrados dentro de ninho de formiga Azteca sp. e em uma árvore apodrecida caída, respectivamente. O ninho de Euglossa townsendiCockerell foi registrado pela primeira vez em uma folha da planta ornamental Cordyline sp. (Asparagaceae. Euglossa intersecta Latreillefoi registrada nidificando dentro de um ninho abandonado de cupim e Euglossa cordata (Linnaeusfoi encontrada nidificando em uma maçaneta tubular de metal de uma janela.

  2. Hormigas arbóreas del Parque Nacional Natural Gorgona (Pacífico de Colombia

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    Patricia Chacón de Ulloa

    2014-02-01

    Full Text Available Este trabajo se enfocó en el conocimiento de la mirmecofauna arbórea de Gorgona, ecosistema insular de la zona de vida de bosque lluvioso tropical (27ºC, 6 000mm de precipitación promedio anual. En noviembre de 2007 se muestrearon 16 árboles mediante la técnica de nebulización usando un insecticida piretroide biodegradable, aplicado en dirección al dosel, desde cuatro alturas diferentes, entre 1 y 15m por encima de la vegetación del sotobosque. Se encontraron 53 especies de Formicidae pertenecientes a 24 géneros y seis subfamilias, sobresaliendo por su riqueza las Formicinae (20 especies y Myrmicinae (17. Por su abundancia, se destacaron especies arbóreas de los géneros Azteca, Dolichoderus (D. bispinosus y D. lutosus, Camponotus (C. atriceps, C. claviscapus, C. championi, C. excisus y Crematogaster (C. brasiliensis, C. carinata, C. curvispinosa. Algunas especies que son muy comunes a nivel del suelo (Wasmannia auropunctata y Camponotus sericeiventris, fueron colectadas a más de 15m de altura. Se resalta la captura de Nesomyrmex pittieri, Crematogaster stolli, Cephalotes basalis, Anochetus bispinosus y Stigmatomma mystriops que usualmente no se detectan en muestreos comunes.

  3. Televisión y tratamiento de la información político-electoral

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    Martha Alicia Márquez Rodríguez

    2004-01-01

    Full Text Available Este artículo describe, mediante un ejercicio de análisis de contenido y aplicación de técnicas cuantitativas, las diferencias respecto a la jerarquización, omisión, evaluación y tratamiento general de la información que se observan en la transmisión de noticias de cuatro noticiarios nocturnos (Televisa, TV Azteca, CNI-Canal 40 e IPN-Canal 11. Los temas de las noticias evaluadas tienen que ver con el periodo de las campañas electorales intermedias federales del 2003 y la información relativa a partidos políticos. El artículo sostiene que la cantidad o calidad de la información sobre política nacional, que se difunde en los medios de comunicación, es un factor que contribuye en el proceso de formación de opinión pública y en última instancia, en un insumo de la cultura política.

  4. Arboreal ants use the "Velcro(R principle" to capture very large prey.

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    Alain Dejean

    2010-06-01

    Full Text Available Plant-ants live in a mutualistic association with host plants known as "myrmecophytes" that provide them with a nesting place and sometimes with extra-floral nectar (EFN and/or food bodies (FBs; the ants can also attend sap-sucking Hemiptera for their honeydew. In return, plant-ants, like most other arboreal ants, protect their host plants from defoliators. To satisfy their nitrogen requirements, however, some have optimized their ability to capture prey in the restricted environment represented by the crowns of trees by using elaborate hunting techniques. In this study, we investigated the predatory behavior of the ant Azteca andreae which is associated with the myrmecophyte Cecropia obtusa. We noted that up to 8350 ant workers per tree hide side-by-side beneath the leaf margins of their host plant with their mandibles open, waiting for insects to alight. The latter are immediately seized by their extremities, and then spread-eagled; nestmates are recruited to help stretch, carve up and transport prey. This group ambush hunting technique is particularly effective when the underside of the leaves is downy, as is the case for C. obtusa. In this case, the hook-shaped claws of the A. andreae workers and the velvet-like structure of the underside of the leaves combine to act like natural Velcro that is reinforced by the group ambush strategy of the workers, allowing them to capture prey of up to 13,350 times the mean weight of a single worker.

  5. Harnessing ant defence at fruits reduces bruchid seed predation in a symbiotic ant-plant mutualism.

    Science.gov (United States)

    Pringle, Elizabeth G

    2014-06-22

    In horizontally transmitted mutualisms, mutualists disperse separately and reassemble in each generation with partners genetically unrelated to those in the previous generation. Because of this, there should be no selection on either partner to enhance the other's reproductive output directly. In symbiotic ant-plant mutualisms, myrmecophytic plants host defensive ant colonies, and ants defend the plants from herbivores. Plants and ants disperse separately, and, although ant defence can indirectly increase plant reproduction by reducing folivory, it is unclear whether ants can also directly increase plant reproduction by defending seeds. The neotropical tree Cordia alliodora hosts colonies of Azteca pittieri ants. The trees produce domatia where ants nest at stem nodes and also at the node between the peduncle and the rachides of the infloresence. Unlike the stem domatia, these reproductive domatia senesce after the tree fruits each year. In this study, I show that the tree's resident ant colony moves into these ephemeral reproductive domatia, where they tend honeydew-producing scale insects and patrol the nearby developing fruits. The presence of ants significantly reduced pre-dispersal seed predation by Amblycerus bruchid beetles, thereby directly increasing plant reproductive output.

  6. Water stress strengthens mutualism among ants, trees, and scale insects.

    Science.gov (United States)

    Pringle, Elizabeth G; Akçay, Erol; Raab, Ted K; Dirzo, Rodolfo; Gordon, Deborah M

    2013-11-01

    Abiotic environmental variables strongly affect the outcomes of species interactions. For example, mutualistic interactions between species are often stronger when resources are limited. The effect might be indirect: water stress on plants can lead to carbon stress, which could alter carbon-mediated plant mutualisms. In mutualistic ant-plant symbioses, plants host ant colonies that defend them against herbivores. Here we show that the partners' investments in a widespread ant-plant symbiosis increase with water stress across 26 sites along a Mesoamerican precipitation gradient. At lower precipitation levels, Cordia alliodora trees invest more carbon in Azteca ants via phloem-feeding scale insects that provide the ants with sugars, and the ants provide better defense of the carbon-producing leaves. Under water stress, the trees have smaller carbon pools. A model of the carbon trade-offs for the mutualistic partners shows that the observed strategies can arise from the carbon costs of rare but extreme events of herbivory in the rainy season. Thus, water limitation, together with the risk of herbivory, increases the strength of a carbon-based mutualism.

  7. Community analysis of microbial sharing and specialization in a Costa Rican ant-plant-hemipteran symbiosis.

    Science.gov (United States)

    Pringle, Elizabeth G; Moreau, Corrie S

    2017-03-15

    Ants have long been renowned for their intimate mutualisms with trophobionts and plants and more recently appreciated for their widespread and diverse interactions with microbes. An open question in symbiosis research is the extent to which environmental influence, including the exchange of microbes between interacting macroorganisms, affects the composition and function of symbiotic microbial communities. Here we approached this question by investigating symbiosis within symbiosis. Ant-plant-hemipteran symbioses are hallmarks of tropical ecosystems that produce persistent close contact among the macroorganism partners, which then have substantial opportunity to exchange symbiotic microbes. We used metabarcoding and quantitative PCR to examine community structure of both bacteria and fungi in a Neotropical ant-plant-scale-insect symbiosis. Both phloem-feeding scale insects and honeydew-feeding ants make use of microbial symbionts to subsist on phloem-derived diets of suboptimal nutritional quality. Among the insects examined here, Cephalotes ants and pseudococcid scale insects had the most specialized bacterial symbionts, whereas Azteca ants appeared to consume or associate with more fungi than bacteria, and coccid scale insects were associated with unusually diverse bacterial communities. Despite these differences, we also identified apparent sharing of microbes among the macro-partners. How microbial exchanges affect the consumer-resource interactions that shape the evolution of ant-plant-hemipteran symbioses is an exciting question that awaits further research. © 2017 The Author(s).

  8. Organic matter characterization and decomposition dynamics in sub-Antarctic streams impacted by invasive beavers Caracterización de la materia orgánica y la dinámica de descomposición en arroyos subantárticos impactados por castores invasores

    Directory of Open Access Journals (Sweden)

    Erica Ulloa

    2012-11-01

    Full Text Available Despite being a relatively remote and well conserved area, the sub-Antarctic ecoregion faces pressing global threats from climate change, the ozone hole and introduced species. Its freshwater ecosystems are one of the least studied components of this biome, but they are known to confront a host of invasive taxa including trout and beavers. We set out to understand the basic characterization and dynamics of organic matter processing and decomposition in sub-Antarctic streams under natural forest (NF conditions and in ponds constructed by North American beavers (Castor canadensis (BP. We found these streams have a naturally stable benthic organic matter regime throughout the year with a peak in leaf input from Nothofagus pumilio in autumn. Beaver ponds significantly increased the retention of organic matter and caused significantly higher decomposition rates, probably associated with increased density and biomass of Hyalella spp. As expected, leaf decay rates for N. pumilio, a deciduous species, were higher (NF: -0.0028 day- ± 0.0001 SE; BP: -0.0118 day-1 ± 0.0009 SE than N. betuloides (a broad-leaf evergreen (NF: -0.0018 day-1 ± 0.0005 SE; BP: -0.0040 day-1 ± 0.0003 SE. Overall these results indicate that the naturally low decomposition rates (slower than 89% of a global survey of decay rates for these cold, oligotrophic streams are being modified by introduced beavers to resemble more temperate latitudes.A pesar de ser una zona relativamente remota y bien conservado, la ecorregión subantártica se enfrenta a presiones por amenazas globales por el cambio climático, el agujero de ozono y las especies introducidas. Los ecosistemas de agua dulce son uno de los componentes menos estudiados de este bioma, pero se sabe que enfrentan una serie de taxones invasivos como la trucha y los castores. El propósito de este estudio es entender la caracterización básica y dinámica de descomposición de la materia orgánica en arroyos subantárticos de

  9. Investigating the emerging role of comparative proteomics in the search for new biomarkers of metal contamination under varying abiotic conditions

    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); Sohm, Bénédicte, E-mail: benedicte.sohm@univ-lorraine.fr [Laboratoire Interdisciplinaire des Environnements Continentaux (LIEC), CNRS UMR 7360, Université de Lorraine – Metz (France); Parant, Marc, E-mail: marc.parant@univ-lorraine.fr [Laboratoire Interdisciplinaire des Environnements Continentaux (LIEC), CNRS UMR 7360, Université de Lorraine – Metz (France); Immel, Françoise, E-mail: Francoise.Immel@u-bourgogne.fr [Biogéosciences, CNRS UMR 6282, Université de Bourgogne – Dijon (France); Usseglio-Polatera, Philippe, E-mail: philippe.usseglio-polatera@univ-lorraine.fr [Laboratoire Interdisciplinaire des Environnements Continentaux (LIEC), CNRS UMR 7360, Université de Lorraine – Metz (France)

    2016-08-15

    This study aims at investigating the potential use of comparative proteomics as a multi-marker approach of metal contamination, taking into account the potential confounding effect of water temperature. The major objective was to identify combinations of proteins specifically responding to a given metal, even if included in a metal mixture. The diagnostic approach was performed via the comparative analysis of protein expression on spot mapping provided by adult males of Gammarus pulex (Amphipoda, Crustacea) respectively exposed to arsenate (As), cadmium (Cd) or a binary mixture of these metals (AsCd) at three realistic temperatures (5, 10 and 15 °C). Proteomic expression analysis was performed by Differential in-Gel Electrophoresis (2D-DiGE), and completed by an adapted inferential statistical approach. Combinations of under/over-expressed protein spots discriminated the metal identity. However, none of these spots discriminated both the individual metal effect (As or Cd) and its effect in metal mixture (AsCd) whatever the tested temperature. Some limits of the two-dimensional analysis of protein spot maps in G. pulex have been highlighted: (i) the presence of contaminating peptides and/or abundant “déja-vu” proteins which can mask the responses of other proteins of interest or (ii) the presence of post-translational modifications. An optimization of the experimental design (especially during the sample preparation) has been described for future investigations. This study has also highlighted (i) the importance of precisely identifying the protein spots of interest to avoid erroneous interpretations in terms of action mechanisms of chemicals and (ii) the importance of working under controlled laboratory conditions with a temperature close to 10 °C. In such conditions, we have demonstrated a higher impact of As than Cd on the energetic metabolism of Gammarus. This As impact is reduced in AsCd mixture confirming the antagonistic interaction of this binary

  10. Epifauna dynamics at an offshore foundation--implications of future wind power farming in the North Sea.

    Science.gov (United States)

    Krone, Roland; Gutow, Lars; Joschko, Tanja J; Schröder, Alexander

    2013-04-01

    In the light of the introduction of thousands of large offshore wind power foundations into the North Sea within the next decades, this manuscript focuses on the biofouling processes and likely reef effects. The study explores the macrozoobenthos (biofouling) colonization at an offshore platform which is comparable to offshore wind turbine foundations. A total of 183 single samples were taken and the parameters water depth and time were considered comparing biofouling masses and communities. The blue mussel Mytilus edulis, Anthozoa and the Amphipoda Jassa spp. were the dominant species. The community from the 1 m zone and those from the 5 and 20-28 m zones can clearly be differentiated. The 10 m zone community represents the transition between the M. edulis dominated 1 m and 5 m zones and the Anthozoa dominated 20-28 m zone. In the future offshore wind farms, thousands of wind turbine foundations will provide habitat for a hard bottom fauna which is otherwise restricted to the sparse rocky habitats scattered within extensive sedimentary soft bottoms of the German Bight. However, offshore wind power foundations cannot be considered natural rock equivalents as they selectively increase certain natural hard bottom species. The surface of the construction (1280 m²) was covered by an average of 4300 kg biomass. This foundation concentrates on its footprint area (1024 m²) 35 times more macrozoobenthos biomass than the same area of soft bottom in the German exclusive economic zone (0.12 kg m(-2)), functioning as a biomass hotspot. Concerning the temporal biomass variation, we assume that at least 2700 kg biomass was exported on a yearly basis. 345 × 10(4) single mussel shells of different sizes were produced during the study period. It is anticipated that the M. edulis abundance will increase in the North Sea due to the expansion of the offshore wind farm development. This will result in the enhanced production of secondary hard substrate (mussel shells

  11. Investigating the emerging role of comparative proteomics in the search for new biomarkers of metal contamination under varying abiotic conditions

    International Nuclear Information System (INIS)

    Vellinger, Céline; Sohm, Bénédicte; Parant, Marc; Immel, Françoise; Usseglio-Polatera, Philippe

    2016-01-01

    This study aims at investigating the potential use of comparative proteomics as a multi-marker approach of metal contamination, taking into account the potential confounding effect of water temperature. The major objective was to identify combinations of proteins specifically responding to a given metal, even if included in a metal mixture. The diagnostic approach was performed via the comparative analysis of protein expression on spot mapping provided by adult males of Gammarus pulex (Amphipoda, Crustacea) respectively exposed to arsenate (As), cadmium (Cd) or a binary mixture of these metals (AsCd) at three realistic temperatures (5, 10 and 15 °C). Proteomic expression analysis was performed by Differential in-Gel Electrophoresis (2D-DiGE), and completed by an adapted inferential statistical approach. Combinations of under/over-expressed protein spots discriminated the metal identity. However, none of these spots discriminated both the individual metal effect (As or Cd) and its effect in metal mixture (AsCd) whatever the tested temperature. Some limits of the two-dimensional analysis of protein spot maps in G. pulex have been highlighted: (i) the presence of contaminating peptides and/or abundant “déja-vu” proteins which can mask the responses of other proteins of interest or (ii) the presence of post-translational modifications. An optimization of the experimental design (especially during the sample preparation) has been described for future investigations. This study has also highlighted (i) the importance of precisely identifying the protein spots of interest to avoid erroneous interpretations in terms of action mechanisms of chemicals and (ii) the importance of working under controlled laboratory conditions with a temperature close to 10 °C. In such conditions, we have demonstrated a higher impact of As than Cd on the energetic metabolism of Gammarus. This As impact is reduced in AsCd mixture confirming the antagonistic interaction of this binary

  12. A “Rosetta Stone” for metazoan zooplankton: DNA barcode analysis of species diversity of the Sargasso Sea (Northwest Atlantic Ocean)

    Science.gov (United States)

    Bucklin, Ann; Ortman, Brian D.; Jennings, Robert M.; Nigro, Lisa M.; Sweetman, Christopher J.; Copley, Nancy J.; Sutton, Tracey; Wiebe, Peter H.

    2010-12-01

    Species diversity of the metazoan holozooplankton assemblage of the Sargasso Sea, Northwest Atlantic Ocean, was examined through coordinated morphological taxonomic identification of species and DNA sequencing of a ˜650 base-pair region of mitochondrial cytochrome oxidase I (mtCOI) as a DNA barcode (i.e., short sequence for species recognition and discrimination). Zooplankton collections were made from the surface to 5,000 meters during April, 2006 on the R/V R.H. Brown. Samples were examined by a ship-board team of morphological taxonomists; DNA barcoding was carried out in both ship-board and land-based DNA sequencing laboratories. DNA barcodes were determined for a total of 297 individuals of 175 holozooplankton species in four phyla, including: Cnidaria (Hydromedusae, 4 species; Siphonophora, 47); Arthropoda (Amphipoda, 10; Copepoda, 34; Decapoda, 9; Euphausiacea, 10; Mysidacea, 1; Ostracoda, 27); and Mollusca (Cephalopoda, 8; Heteropoda, 6; Pteropoda, 15); and Chaetognatha (4). Thirty species of fish (Teleostei) were also barcoded. For all seven zooplankton groups for which sufficient data were available, Kimura-2-Parameter genetic distances were significantly lower between individuals of the same species (mean=0.0114; S.D. 0.0117) than between individuals of different species within the same group (mean=0.3166; S.D. 0.0378). This difference, known as the barcode gap, ensures that mtCOI sequences are reliable characters for species identification for the oceanic holozooplankton assemblage. In addition, DNA barcodes allow recognition of new or undescribed species, reveal cryptic species within known taxa, and inform phylogeographic and population genetic studies of geographic variation. The growing database of "gold standard" DNA barcodes serves as a Rosetta Stone for marine zooplankton, providing the key for decoding species diversity by linking species names, morphology, and DNA sequence variation. In light of the pivotal position of zooplankton in ocean

  13. Eumalacostracan phylogeny and total evidence: limitations of the usual suspects

    Directory of Open Access Journals (Sweden)

    Ferla Matteo P

    2009-01-01

    Full Text Available Abstract Background The phylogeny of Eumalacostraca (Crustacea remains elusive, despite over a century of interest. Recent morphological and molecular phylogenies appear highly incongruent, but this has not been assessed quantitatively. Moreover, 18S rRNA trees show striking branch length differences between species, accompanied by a conspicuous clustering of taxa with similar branch lengths. Surprisingly, previous research found no rate heterogeneity. Hitherto, no phylogenetic analysis of all major eumalacostracan taxa (orders has either combined evidence from multiple loci, or combined molecular and morphological evidence. Results We combined evidence from four nuclear ribosomal and mitochondrial loci (18S rRNA, 28S rRNA, 16S rRNA, and cytochrome c oxidase subunit I with a newly synthesized morphological dataset. We tested the homogeneity of data partitions, both in terms of character congruence and the topological congruence of inferred trees. We also performed Bayesian and parsimony analyses on separate and combined partitions, and tested the contribution of each partition. We tested for potential long-branch attraction (LBA using taxon deletion experiments, and with relative rate tests. Additionally we searched for molecular polytomies (spurious clades. Lastly, we investigated the phylogenetic stability of taxa, and assessed their impact on inferred relationships over the whole tree. We detected significant conflict between data partitions, especially between morphology and molecules. We found significant rate heterogeneity between species for both the 18S rRNA and combined datasets, introducing the possibility of LBA. As a test case, we showed that LBA probably affected the position of Spelaeogriphacea in the combined molecular evidence analysis. We also demonstrated that several clades, including the previously reported and surprising clade of Amphipoda plus Spelaeogriphacea, are 'supported' by zero length branches. Furthermore we showed

  14. Taxocenosis of mollusks and crustaceans on roots of Rhizophora mangle (Rhizophoraceae at Cispatá Bay, Córdoba, Colombia

    Directory of Open Access Journals (Sweden)

    Jorge Alexander Quirós R

    2013-05-01

    EN LA BAHÍA DE CISPATÁ, CÓRDOBA, COLOMBIA A pesar del conocimiento existente sobre la ecología de los manglares en la bahía de Cispatá, pocos estudios han sido enfocados en invertebrados asociados a las raíces del mangle rojo. Entre diciembre 2010 y septiembre 2011, se evaluó la estructura de los ensamblajes de moluscos y crustáceos asociados a las raíces de Rhizophora mangle en dos sectores de muestreo de la bahía de Cispatá, Colombia. Para la recolección del material biológico se tomaron al azar tres raíces de mangle homogéneas en cuanto al diámetro. Los organismos fueron obtenidos de la raíz raspando la superficie con un cuchillo, luego fueron separados y fijados en formalina al 10% para su posterior identificación. De los 12289 individuos recolectados en los cuatro muestreos, 10470 pertenecieron al phylum Mollusca (85,2% y los restantes 1819 al subphylum Crustacea (14,8%. Para los moluscos se identificaron 14 especies distribuidas en 12 familias y dos clases; Bivalvia y Gastropoda. Para los crustáceos se identificaron 24 especies distribuidas en 16 familias y cuatro órdenes; Sessillia, Decapoda, Isopoda y Amphipoda. En los dos sectores de muestreo Mytella charruana, Balanus eburneus y Crassostrea rhizophorae fueron las especies más importantes en términos de abundancia, no obstante M. charruana y B. eburneus presentan una gran capacidad de adaptación y ajuste a las variaciones hidroclimáticas, mostrándose como especies fuertemente eurihalinas, lo que se relejó en la dominancia de dichas especies en el sector B. La presencia de Petrolisthes armatus y Aratus pisonii indica que son especies de bosques de manglar con gran movilidad y mecanismos de adaptación fisiológicos, lo que justifica su presencia en el sector A.

  15. Unexpectedly higher metazoan meiofauna abundances in the Kuril-Kamchatka Trench compared to the adjacent abyssal plains

    Science.gov (United States)

    Schmidt, Christina; Martínez Arbizu, Pedro

    2015-01-01

    We studied meiofauna standing stocks and community structure in the Kuril-Kamchatka Trench and its adjacent abyssal plains in the northwestern Pacific Ocean. In general, the Nematoda were dominant (93%) followed by the Copepoda (4%). Nematode abundances ranged from 87% to 96%; those of copepods from 2% to 7%. The most diverse deployment yielded 17 taxa: Acari, Amphipoda, Annelida, Bivalvia, Coelenterata, Copepoda, Cumacea, Gastrotricha, Isopoda, Kinorhyncha, Loricifera, Nematoda, Ostracoda, Priapulida, Tanaidacea, Tantulocarida, and Tardigrada. Nauplii were also present. Generally, the trench slope and the southernmost deployments had the highest abundances (850-1392 individuals/cm2). The results of non-metric multidimensional scaling indicated that these deployments were similar to each other in meiofauna community structure. The southernmost deployments were located in a zone of higher particulate organic carbon (POC) flux (g Corg m-2 yr-1), whereas the trench slope should have low POC flux due to depth attenuation. Also, POC and abundance were significantly correlated in the abyssal plains. This correlation may explain the higher abundances at the southernmost deployments. Lateral transport was also assumed to explain high meiofauna abundances on the trench slope. Abundances were generally higher than expected from model results. ANOSIM revealed significant differences between the trench slope and the northern abyssal plains, between the central abyssal plains and the trench slope, between the trench slope and the southern abyssal plains, between the central and the southern abyssal plains, and between the central and northern deployments. The northern and southern abyssal plains did not differ significantly. In addition, a U-test revealed highly significant differences between the trench-slope and abyssal deployments. The taxa inhabited mostly the upper 0-3 cm of the sediment layer (Nematoda 80-90%; Copepoda 88-100%). The trench-slope and abyssal did not differ

  16. Comparison of laboratory single species and field population-level effects of the pyrethroid insecticide lambda-cyhalothrin on freshwater invertebrates.

    Science.gov (United States)

    Schroer, A F W; Belgers, J D M; Brock, T C M; Matser, A M; Maund, S J; Van den Brink, P J

    2004-04-01

    The toxicity of the pyrethroid insecticide lambda-cyhalothrin to freshwater invertebrates has been investigated using data from short-term laboratory toxicity tests and in situ bioassays and population-level effects in field microcosms. In laboratory tests, patterns of toxicity were consistent with previous data on pyrethroids. The midge Chaoborus obscuripes was most sensitive (48- and 96-h EC50 = 2.8 ng/L). Other insect larvae (Hemiptera, Ephemeroptera) and macrocrustacea (Amphipoda, Isopoda) were also relatively sensitive, with 48- and 96-h EC50 values between 10 and 100 ng/L. Generally, microcrustacea (Cladocera, Copepoda) and larvae of certain insect groups (Odonata and Chironomidae) were less sensitive, with 48-h EC50 values higher than 100 ng/L. Mollusca and Plathelminthes were insensitive and were unaffected at concentrations at and above the water solubility (5 microg/L). Generally, the EC50 values based on initial population responses in field enclosures were similar to values derived from laboratory tests with the same taxa. Also, the corresponding fifth and tenth percentile hazard concentrations (HC5 and HC10) were similar (laboratory HC5 = 2.7 ng/L and field HC5 = 4.1 ng/L; laboratory and field HC10 = 5.1 ng/L), at least when based on the same sensitive taxonomic groups (insects and crustaceans) and when a similar concentration range was taken into account. In the three field enclosure experiments and at a treatment level of 10 ng/L, consistent effects were observed for only one population (Chaoborus obscuripes), with recovery taking place within 3 to 6 weeks. The laboratory HC5 (2.7 ng/L) and HC10 (5.1 ng/L) based on acute EC50 values of all aquatic arthropod taxa were both lower than this 10 ng/L, a concentration that might represent the "regulatory acceptable concentration." The HC5 and HC10 values in this study in The Netherlands (based on static laboratory tests with freshwater arthropods) were very similar to those derived from a previous study in

  17. Pesticide impact study in the peri-urban horticultural area of Gran La Plata, Argentina.

    Science.gov (United States)

    Mac Loughlin, Tomás M; Peluso, Leticia; Marino, Damián J G

    2017-11-15

    Vegetable production systems are characterized by intense pesticide use, yet the effects on the surrounding environment are largely unknown and need to be studied. Given this knowledge gap, the objective of this work is to determine the impact of horticulture on a representative watercourse by conducting an integrated study of the occurrence and concentration of pesticides in bottom sediments and their relation to lethal and sublethal effects on benthic fauna. Two sampling campaigns were conducted during seasons of low and high pesticide application in five sites along the Carnaval creek, located in the peri-urban area of La Plata City (Buenos Aires, Argentina). The samples were tested for 36 pesticide compounds by GC-MS and LC-MS, and whole-sediment laboratory toxicity tests were performed using the native amphipod Hyalella curvispina. The results showed a general but variable distribution in the concentrations detected along the stream. For each sampling campaign (first/second), the total pesticide loads, measured as the sum of herbicides, insecticides and fungicides, were 1080/2329, 3715/88, and 367/5ngg -1 dw, respectively. Lethal and sublethal effects were observed in both sampling campaigns. In order to correlate both sets of results, data were assessed by multivariate analysis, including principal component analysis. The observed toxicity was considered to be mainly due to insecticides; thus, horticultural practices have an impact on nearby watercourses and can potentially endanger the benthic fauna. This is the first study in Argentina to assess the impact of pesticides on aquatic environments close to horticultural production areas. Copyright © 2017 Elsevier B.V. All rights reserved.

  18. Composição da fauna cavernícola brasileira, com uma análise preliminar da distribuição dos taxons

    Directory of Open Access Journals (Sweden)

    Eleonora Trajano

    1990-01-01

    Full Text Available New data on Brazilian cave fauna are added to previous surveys and the relative abundance and distribution of the cavernicolous taxa is discussed. Terrestrial representatives of several arthropod families and genera are common in both tropical and subtropical Brazilian caves: Endecous and Eidmanacris crickets, Reduviidae heteropterans, Carabidae, Catopinae and Ptilodactylidae beetles, dipterans such as the Chironomidae, Keroplatidae, Phoridae and Drosophilidae, Hydropsychidae trichopterans, Pseudonnanolenidae and Chelodesnidae millipedes, Plato, Ctenus, Loxosceles and Blechroscelis spiders, Pachylinae opilionids, Chernetidae pseudoscorpions and acarians such as the Macrochelidae and Uropodidae. Other taxa are mainly or exclusively tropical Blattelidae, Blattidae and BlaberidaE cockroaches, Histeridae beetles, Noctuoidea moths, social insects as termites and ants, Styloniscidae isopods, Migalomorpha spiders, Amblypigi On the other hand, Psauridae spiders, Goniosoma and Tricommatinae opilionids, Elmidae beetles, and Philosciidae isopods seems to be mainly subtropical. Brazilian aquatic cave fauna seems to be less diversified than the terrestrial one. Siluriform fishes such as pimelodids, trichomycterids and loricariids predominate throughout the country, besides decapod (Macrobrachium shrimps, Potamidae crabs, Aegla anomurans, the latter exclusive of subtropical caves and amphipod (Spelaeogammarus, in tropical caves, and Hyalella crustaceans. Insect larvae (e.g. Elmidae coleopterans, Nematocera dipterans, trichopterans and adults (e.g. Veliidae and Naucoridae heteropterans, Dytiscidae coleopterans, oligochaetes and gastropods such as the Hydrobiidae, are also relatively common. Blechroscelis spiders, Goniosoma opilionids, Zelurus heteropterans, Eidmanacris crickets, Keroplatidae dipterans and Macrobrachium shrimps, among others, live next to the entrance zone in the majority of the caves. But, these animals become troglofiles under certain

  19. Relationship between bifenthrin sediment toxic units and benthic community metrics in urban California streams.

    Science.gov (United States)

    Hall, Lenwood W; Anderson, Ronald D

    2013-08-01

    The objective of this study was to use ecologically relevant field measurements for determining the relationship between bifenthrin sediment toxic units (TUs) (environmental concentrations/Hyalella acute LC50 value) and 15 benthic metrics in four urban California streams sampled from 2006 to 2011. Data from the following four California streams were used in the analysis: Kirker Creek (2006, 2007), Pleasant Grove Creek (2006, 2007, and 2008), Arcade Creek (2009, 2010, and 2011), and Salinas streams (2009, 2010, and 2011). The results from univariate analysis of benthic metrics versus bifenthrin TU calculations for the four California streams with multiple-year datasets combined by stream showed that there were either nonsignificant relationships or lack of metric data for 93 % of cases. For 7 % of the data (4 cases) where significant relationships were reported between benthic metrics and bifenthrin TUs, these relationships were ecologically meaningful. Three of these significant direct relationships were an expression of tolerant benthic taxa (either % tolerant taxa or tolerance values, which are similar metrics), which would be expected to increase in a stressed environment. These direct significant tolerance relationships were reported for Kirker Creek, Pleasant Grove Creek, and Arcade Creek. The fourth significant relationship was an inverse relationship between taxa richness and bifenthrin TUs for the 3-year Pleasant Grove Creek dataset. In summary, only a small percent of the benthic metric × bifenthrin TU relationships were significant for the four California streams. Therefore, the general summary conclusion from this analysis is that there is no strong case for showing consistent meaningful relationships between various benthic metrics used to characterize the status of benthic communities and bifenthrin TUs for these four California streams.

  20. Evaluación ecotoxicológica de sedimentos en una zona del Río Uruguay, con puntos finales indicadores de toxicidad aguda, sub-letal, crónica, reproductiva y teratogénica

    Directory of Open Access Journals (Sweden)

    Diana Míguez Carames

    2011-05-01

    Full Text Available El objetivo de este trabajo fue caracterizar la toxicidad de los sedimentos de una zona del Río Uruguay, aplicando una batería de bioensayos. Las muestras provinieron de: una zona de influencia de descargas domésticas y efluentes de una planta de celulosa (Fray Bentos, una ciudad turística aguas abajo (Las Cañas y otra aguas arriba (Nuevo Berlín, sin influencia directa de dichos vertidos. Los bioensayos aplicados en elutriados fueron: de toxicidad con Photobacterium leiognathi, de reproducción con Ceriodaphnia dubia, de teratogenicidad y letalidad con Pimephales promelas y el ensayo sub-letal en sedimento completo con Hyalella curvispina. Para evaluar la biodisponibilidad y las rutas de toxicidad, se midió el fraccionamiento del 2,4,5-triclorofenol, con resultados: 63% disuelto, 27% adsorbido sobre partículas y el resto sedimentado.Se observó toxicidad por orgánicos y metales con P. leioghnati para todos los sitios. La frecuencia de malformaciones vertebralesde P. promelas fue de 3.3% en Fray Bentos, pero C. dubia sólo mostró efectos en Nuevo Berlín y Las Cañas. Los efectos con H. curvispina se evidenciaron en todas las muestras. Las rutas de toxicidad incluirían la ingestión de contaminantes disueltos y particulados asociados a arcillas y limo. El vínculo causa-efecto para la toxicidad se continuará investigando.

  1. Initial study of arthropods succession and pig carrion decomposition in two freshwater ecosystems in the Colombian Andes.

    Science.gov (United States)

    Barrios, Maria; Wolff, Marta

    2011-10-10

    Entomological succession and trophic roles of arthropods associated with different stages of carcass decomposition were studied to estimate the post-mortem submersion interval in two freshwater ecosystems in the Colombian Andes, at an altitude of 2614 m. Pig carcasses were employed as models placed 68 m apart, one in a stream (lotic) and another in an artificial lake (lentic). Decomposition time to skeletal remains was 74 days in the lake and 80 days in the stream. Six phases of decomposition were established: submerged fresh, early floating, floating decay, bloated deterioration, floating remains and sunken remains. A total of 18,832 organisms associated with the carcasses were collected: 11,487 in the lake (four orders, 19 families and 33 species) and 7345 in the stream (eight orders, 15 families and 25 species). Organisms were classified in the following ecological categories: shredders, collectors, predators, necrophagous, sarcosaprophagous and opportunists. Physical and chemical properties of the habitats, such as water temperature, CO(2) and conductivity, varied according to rainfall. In the lake, shredders (Coleoptera: Tropisternus sp. and Berosus sp.) and collectors (Diptera: Chironomus sp.) were found to be associated with submerged phases. Predators (Odonata) were only present during the first phases. Coleoptera (Dytiscidae) were found during floating decay and bloated deterioration stages. In the stream, shredders (Hyalella sp.) and collectors (Simulium sp.) were found during all stages, whereas the predator Oxelytrum discicolle was found exclusively during the floating stages, during which body temperature increased in a fashion similar to active decay in terrestrial environments. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  2. Relação entre diferentes espécies de formigas e a mirmecófita Cordia nodosa Lamarck (Boraginaceae em áreas de mata ripária na Amazônia mato-grossense Relationship among different plant-ants and its myrmecophite host Cordia nodosa Lamarck (Boraginaceae in a riparian Mato Grosso Amazonian forest

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    Thiago Junqueira Izzo

    2011-01-01

    Full Text Available Os benefícios obtidos por um organismo em uma associação mutualística podem variar em função de fatores ambientais, bem como entre as diferentes espécies que podem estar associadas. Neste trabalho demonstramos que quatro espécies de formigas, Crematogaster brasiliensis, Allomerus octoarticulatus e duas não identificadas do gênero Azteca podem ser encontradas associadas à mirmecófita Cordia nodosa em florestas ripárias sul-amazônicas. Essa composição de espécies de formigas é mais similar a encontrada na Amazônia Andina do que aquela da Amazônia Central brasileira. A colonização por formigas parece ser determinante, pois diminuiu a herbivoria e, consequentemente, aumentou a probabilidade de C. nodosa produzir frutos. Adicionalmente, mesmo não havendo diferença na herbivoria entre plantas colonizadas pelas diferentes espécies de formigas, a probabilidade de uma planta colonizada por formigas do gênero Allomerus produzir frutos é menor do que quando colonizadas pelas outras espécies de formigas. Esse estudo demonstra a dependência de C. nodosa pela colonização de formigas para sua reprodução. Contudo, conforme outros estudos realizados em outras áreas da Amazônia demonstram, nossos resultados também sugerem que Allomerus pode estar castrando as plantas hospedeiras, agindo como parasita em toda a sua distribuição geográfica.The benefits obtained by an organism when involved in a mutualistic interaction vary depending on environmental factors, as well as among the identity of the involved species. In this study, we showed that four ant species, Crematogaster brasiliensis, Allomerus octoarticulatus, and two unidentified Azteca species can be found associated to the myrmecophite Cordia nodosa in riparian forests in the South of Amazonia. This composition of ant-associated species is more similar in forests of Andean Amazon than in Central Amazonia. The colonization of an ant colony on C. nodosa seems to be vital

  3. Especies de hormigas del suelo en el Parque Nacional Natural Gorgona, Pacífico Colombiano

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    Stephany Valdés-Rodríguez

    2014-02-01

    Full Text Available Este trabajo compila registros publicados (1991 y no publicados (2006 sobre las especies de hormigas del PNN Gorgona y aporta nuevos registros de especies recolectadas en 2010. Se recopiló información de 15 diferentes sitios de isla Gorgona (13.82km², incluyendo la pequeña isla de Gorgonilla (0.4899km². Los métodos de recolecta incluyeron trampas de caída, cebos de atún, sacos Winkler, trampas Malaise, red entomológica y captura directa. El inventario de hormigas de suelo y sotobosque resultó en 107 especies y morfoespecies, 46 géneros y 12 subfamilias. Myrmicinae reunió la mayor riqueza (37 especies seguida de Ponerinae (27 y Formicinae (12. Los géneros más ricos fueron Pachycondyla (15 especies, Camponotus (nueve y Pheidole (ocho, mientras que 30 géneros solo presentaron una especie. Doce especies fueron muy comunes: Azteca sp., Atta cephalotes, Camponotus sericeiventris, Eciton vagans, Ectatomma goninion, Gnamptogenys annulata, Odontomachus bauri, Pachycondyla bugabensis, P. harpax, P. verenae, Paraponera clavata y Wasmannia auropunctata. En comparación con otras islas neotropicales, Gorgona tiene un número sorprendentemente elevado de especies de hormigas, ninguna de ellas invasivas. Por tanto, estos resultados sugieren que, mecanismos ecológicos y procesos de recuperación natural en el ecosistema han generado disponibilidad de microhábitats permitiendo la coexistencia una gran riqueza de especies.

  4. Las universidades privadas y la transformación de la educación superior: el caso de puebla, México (2012-2015

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    Alfonso Gómez Rossi

    2017-07-01

    Full Text Available Las políticas neoliberales que se instituyeron en México a partir de la década del 90 transformaron la relación de la ciudadanía mexicana con las diversas universidades públicas del país Azteca. Mientras que en las décadas anteriores el ingreso a la universidad pública había sido legislado como un derecho al que podían acceder todos los ciudadanos, las políticas neoliberales exigían que a partir de ese momento sólo entraran los candidatos que aprobaran el examen con buenas notas y tuvieran buenas calificaciones de la preparatoria o bachillerato de los que provenían. La decisión tuvo consecuencias inesperadas para jóvenes de la generación x y los millennials ya que al no poder acceder a la universidad pública recurrieron a universidades privadas, que en la cultura general fueron llamadas “Universidades Patito” por no ser consideradas buenas instituciones para la educación superior. El surgimiento de diversas universidades las obligó a competir entre ellas para poder atraer nuevos alumnos, a partir de programas de estudio innovadores, que al mismo tiempo fueran redituables. Irónicamente, las universidades públicas al ver el éxito que tenían estas carreras las incorporaron posteriormente a su matrícula, convirtiendo a las universidades privadas pequeñas en laboratorios experimentales de conocimiento.

  5. Sobre la primitiva organización gentilicia

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    1973-01-01

    Full Text Available L'A. établit la relation entre l'organisation gentilice grecque et romaine et le calendrier de ces peuples. Il montre également la relation entre l'organisation gentilice des indiens nord-américains et un modèle prédéterminé de huit 'gens' pour chaque tribu. Il démontre finalement le caractère décimal de l'organisation gentilice inca qui s'oppose a l'organisation aztèque de type vicésimal liée a son calendrier. En raison de tout ceci, l'A. conclut que le modèle général gentilice de ces peuples est de caractère mythique, rejetant ainsi le concept qui veut que l'organisation gentilice typique se forme a partir de l'évolution naturelle des organisations familiales primitives. Se establece la relación existente entre la organización gentilicia griega y romana con el calendario usado por estos pueblos. Asimismo la relación existente entre la organización gentilicia de los indios norteamericanos y un patrón predeterminado de ocho gens para cada tribu. Finalmente se establece el carácter decimal de la organización gentilicia incaica, en contraposición a la vigesimal azteca que se relaciona con el calendario usado en esta cultura. Con esta evidencia se concluye en que el patrón general gentilicio de estos pueblos es de carácter mítico, rechazándose así el concepto de que la organización gentilicia típica se forma por la evolución natural de las organizaciones familiares primarias.

  6. A Keystone Ant Species Provides Robust Biological Control of the Coffee Berry Borer Under Varying Pest Densities.

    Science.gov (United States)

    Morris, Jonathan R; Vandermeer, John; Perfecto, Ivette

    2015-01-01

    Species' functional traits are an important part of the ecological complexity that determines the provisioning of ecosystem services. In biological pest control, predator response to pest density variation is a dynamic trait that impacts the provision of this service in agroecosystems. When pest populations fluctuate, farmers relying on biocontrol services need to know how natural enemies respond to these changes. Here we test the effect of variation in coffee berry borer (CBB) density on the biocontrol efficiency of a keystone ant species (Azteca sericeasur) in a coffee agroecosystem. We performed exclosure experiments to measure the infestation rate of CBB released on coffee branches in the presence and absence of ants at four different CBB density levels. We measured infestation rate as the number of CBB bored into fruits after 24 hours, quantified biocontrol efficiency (BCE) as the proportion of infesting CBB removed by ants, and estimated functional response from ant attack rates, measured as the difference in CBB infestation between branches. Infestation rates of CBB on branches with ants were significantly lower (71%-82%) than on those without ants across all density levels. Additionally, biocontrol efficiency was generally high and did not significantly vary across pest density treatments. Furthermore, ant attack rates increased linearly with increasing CBB density, suggesting a Type I functional response. These results demonstrate that ants can provide robust biological control of CBB, despite variation in pest density, and that the response of predators to pest density variation is an important factor in the provision of biocontrol services. Considering how natural enemies respond to changes in pest densities will allow for more accurate biocontrol predictions and better-informed management of this ecosystem service in agroecosystems.

  7. Arboreal Ants Use the “Velcro® Principle” to Capture Very Large Prey

    Science.gov (United States)

    Dejean, Alain; Leroy, Céline; Corbara, Bruno; Roux, Olivier; Céréghino, Régis; Orivel, Jérôme; Boulay, Raphaël

    2010-01-01

    Plant-ants live in a mutualistic association with host plants known as “myrmecophytes” that provide them with a nesting place and sometimes with extra-floral nectar (EFN) and/or food bodies (FBs); the ants can also attend sap-sucking Hemiptera for their honeydew. In return, plant-ants, like most other arboreal ants, protect their host plants from defoliators. To satisfy their nitrogen requirements, however, some have optimized their ability to capture prey in the restricted environment represented by the crowns of trees by using elaborate hunting techniques. In this study, we investigated the predatory behavior of the ant Azteca andreae which is associated with the myrmecophyte Cecropia obtusa. We noted that up to 8350 ant workers per tree hide side-by-side beneath the leaf margins of their host plant with their mandibles open, waiting for insects to alight. The latter are immediately seized by their extremities, and then spread-eagled; nestmates are recruited to help stretch, carve up and transport prey. This group ambush hunting technique is particularly effective when the underside of the leaves is downy, as is the case for C. obtusa. In this case, the hook-shaped claws of the A. andreae workers and the velvet-like structure of the underside of the leaves combine to act like natural Velcro® that is reinforced by the group ambush strategy of the workers, allowing them to capture prey of up to 13,350 times the mean weight of a single worker. PMID:20593032

  8. CALIDAD DE FRUTOS DE MATERIALES COMERCIALES DE PAPAYA ROJA PRODUCIDOS EN YUCATÁN, MÉXICO

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    Felipe Santamaría

    2015-01-01

    Full Text Available La variedad Maradol es la principal papa - ya cultivada en México y uno de los principales cultivos del estado de Yucatán. Presenta algunos inconvenientes, como la susceptibilidad a viro - sis, por lo que se buscan nuevos materiales que puedan superar en rendimiento a Maradol, pero es necesario que presenten características de cali - dad similares. El objetivo del presente trabajo fue evaluar las características de calidad de los fru - tos de nuevos genotipos producidos en Yucatán. Se usaron 6 materiales comerciales (Maradol, Sensation, Intenzza, Siluet, Lenia Plus y Jíbara y 2 híbridos generados por INIFAP (Azteca y MSXJ. Se evaluó el tamaño de los frutos, color de cáscara y pulpa, firmeza de la pulpa y conte - nido de sólidos solubles totales. En el tamaño de frutos, excepto Jíbara que es muy grande (2,900 kg y Siluet que es muy pequeño (1,200 kg, los 6 materiales restantes fueron similares a Maradol. En color de la cás - cara, Intenzza y Siluet presentaron tono similar a Maradol (65 a 67º pero fueron más luminosos. Siluet y Sensation tuvieron mayor contenido de grados Brix que Maradol, pero también menor firmeza de la pulpa. Considerando el tamaño de los frutos, la firmeza de la pulpa, el contenido desólidos solubles totales y el color de la cáscara y pulpa, los genotipos Sensation, Lenia Plus y MSXJ presentan buenas características, por lo que pueden competir en calidad con la variedad Maradol.

  9. A checklist of the ants (Hymenoptera: Formicidae of the department of Antioquia, Colombia and new records for the country

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    Erika Valentina Vergara-Navarro

    2013-12-01

    Full Text Available Antioquia is a state (department of Colombia, located in the northwestern Andes of South America. Geologically, the northwestern region of the Western Range in Antioquia and Chocó includes the fault resulting from the connection between the Isthmus of Panamá and South America. The Occidental and Central cordilleras in Colombia are characterized by a number of reliefs, valleys and water basins, containing historical biological refuges and endemisms. In this study, we present the first species-level checklist of the 255 species (in 64 genera and 14 subfamilies of ants currently known in Antioquia. One hundred and fifty-two (152 species had previously been registered for the state in different publications. Here, 103 additional species are recognized. Most of these species are distributed in other bioregions of the country as well. Forty-six percent are present in the Amazon Province and 36% in the Colombian Orinoco River basin. Less than 3% are found in the arid lands of the Colombian Caribbean area, Guyana, and the Colombian Pacific Province, plus the Caribbean islands. Sixty-three percent of the species are shared with Costa Rica. Our checklist constitutes the largest roster of ants at the species level for a state in Colombia to date and constitutes the beginning of the assessment of ant diversity in Antioquia. Many more field trips are necessary to gain a better understanding of the ant composition of this state. The following 13 species are new to the records for Colombia: Azteca diabolica, Camponotus amoris, C. eurynotus, C. pachylepis, C. propinquus, C. tonduzi, Cerapachys toltecus, Cylindromyrmex whymperi, Myrmicocrypta urichi, Pheidole angulifera, Pseudomyrmex lisus, Solenopsis subterranea and Trachymyrmex zeteki

  10. Caterpillars and fungal pathogens: two co-occurring parasites of an ant-plant mutualism.

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    Olivier Roux

    Full Text Available In mutualisms, each interacting species obtains resources from its partner that it would obtain less efficiently if alone, and so derives a net fitness benefit. In exchange for shelter (domatia and food, mutualistic plant-ants protect their host myrmecophytes from herbivores, encroaching vines and fungal pathogens. Although selective filters enable myrmecophytes to host those ant species most favorable to their fitness, some insects can by-pass these filters, exploiting the rewards supplied whilst providing nothing in return. This is the case in French Guiana for Cecropia obtusa (Cecropiaceae as Pseudocabima guianalis caterpillars (Lepidoptera, Pyralidae can colonize saplings before the installation of their mutualistic Azteca ants. The caterpillars shelter in the domatia and feed on food bodies (FBs whose production increases as a result. They delay colonization by ants by weaving a silk shield above the youngest trichilium, where the FBs are produced, blocking access to them. This probable temporal priority effect also allows female moths to lay new eggs on trees that already shelter caterpillars, and so to occupy the niche longer and exploit Cecropia resources before colonization by ants. However, once incipient ant colonies are able to develop, they prevent further colonization by the caterpillars. Although no higher herbivory rates were noted, these caterpillars are ineffective in protecting their host trees from a pathogenic fungus, Fusarium moniliforme (Deuteromycetes, that develops on the trichilium in the absence of mutualistic ants. Therefore, the Cecropia treelets can be parasitized by two often overlooked species: the caterpillars that shelter in the domatia and feed on FBs, delaying colonization by mutualistic ants, and the fungal pathogen that develops on old trichilia. The cost of greater FB production plus the presence of the pathogenic fungus likely affect tree growth.

  11. Historia breve de las enfermedades tropicales en América

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    Dulce María Delgadillo Álvarez

    2016-02-01

    Full Text Available La región tropical de la Tierra comprende la zona entre los trópicos de Cáncer y de Capricornio y es en esta franja en donde se localizan países con grandes riquezas naturales pero con economías de ingresos bajos o medios-bajos. Aunado a esto, las características climatológicas de la región son propicias para el desarrollo de organismos patógenos que causan enfermedades graves en la población humana. El término enfermedad tropical, es resultado de un proceso histórico social observado por los europeos durante la conquista y la colonia pues, en el trópico americano, las enfermedades tropicales no existían antes de la llegada de los españoles. Cuando los conquistadores llegaron llevaron consigo patógenos que causaron la muerte de casi el 90 % de la población original siendo las epidemias de viruela, sarampión y gripe las más devastadoras. La conquista del continente fue posible en gran medida por el intercambio biológico entre conquistadores y conquistados y estuvo acompañada de la destrucción de las dos civilizaciones americanas más avanzadas, la azteca en México y la inca en Perú. Durante los siguientes siglos, el intercambio biológico ha sido más amplio; las enfermedades tropicales están ahora presentes en todo el mundo y deben ser atendidas no importando la región del mundo en la que se manifiesten.

  12. Stage-dependent responses to emergent habitat heterogeneity: consequences for a predatory insect population in a coffee agroecosystem.

    Science.gov (United States)

    Liere, Heidi; Perfecto, Ivette; Vandermeer, John

    2014-08-01

    Interactions among members of biological communities can create spatial patterns that effectively generate habitat heterogeneity for other members in the community, and this heterogeneity might be crucial for their persistence. For example, stage-dependent vulnerability of a predatory lady beetle to aggression of the ant, Azteca instabilis, creates two habitat types that are utilized differently by the immature and adult life stages of the beetle. Due to a mutualistic association between A. instabilis and the hemipteran Coccus viridis - which is A. orbigera main prey in the area - only plants around ant nests have high C. viridis populations. Here, we report on a series of surveys at three different scales aimed at detecting how the presence and clustered distribution of ant nests affect the distribution of the different life stages of this predatory lady beetle in a coffee farm in Chiapas, Mexico. Both beetle adults and larvae were more abundant in areas with ant nests, but adults were restricted to the peripheries of highest ant activity and outside the reach of coffee bushes containing the highest densities of lady beetle larvae. The abundance of adult beetles located around trees with ants increased with the size of the ant nest clusters but the relationship is not significant for larvae. Thus, we suggest that A. orbigera undergoes an ontogenetic niche shift, not through shifting prey species, but through stage-specific vulnerability differences against a competitor that renders areas of abundant prey populations inaccessible for adults but not for larvae. Together with evidence presented elsewhere, this study shows how an important predator is not only dependent on the existence of two qualitatively distinct habitat types, but also on the spatial distribution of these habitats. We suggest that this dependency arises due to the different responses that the predator's life stages have to this emergent spatial pattern.

  13. Impact of Regionally Distinct Agroecosystem Communities on the Potential for Autonomous Control of the Coffee Leaf Rust.

    Science.gov (United States)

    Hajian-Forooshani, Zachary; Rivera Salinas, Iris Saraeny; Jiménez-Soto, Estelí; Perfecto, Ivette; Vandermeer, John

    2016-12-01

    Recent theoretical work suggests that two ineffective control agents can provide effective biological control when coupled together. We explore the implications of this work with the system of coffee leaf rust (CLR), caused by the fungal agent Hemileiae vastatrix, and two of its natural enemies, a fungal pathogen (Lecanicillium lecanii) and a spore predator (Mycodiplosis hemileiae). Here we report on comparative surveys of the CLR and its two natural enemies in Mexico, where the CLR has been at epidemic status since 2012, and Puerto Rico, where the CLR is present but has not reached epidemic densities. We found that the densities of the two control agents per CLR lesion is higher in Puerto Rico than in Mexico, and we hypothesize that their joint presence at higher densities is contributing to the suppression of the CLR in Puerto Rico but not in Mexico. Furthermore, we found that the presence of Azteca sericeasur, a keystone ant species that occurs in Mexico but not Puerto Rico, significantly reduces the prevalence of M. hemileiae on coffee plants. Our work provides data that allows us to hypothesize that the joint presence of these two control agents may potentially provide control of the CLR and also highlights the importance of regionally specific communities within agroecosystems, and how variation in community composition may lead to varying outcomes for biological control. Additionally, this is the first report of the presence of a potentially important biological control agent, M. hemileiae, in Latin America and the Caribbean. © The Authors 2016. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  14. The ant genomes have been invaded by several types of mariner transposable elements

    Science.gov (United States)

    Lorite, Pedro; Maside, Xulio; Sanllorente, Olivia; Torres, María I.; Periquet, Georges; Palomeque, Teresa

    2012-12-01

    To date, only three types of full-length mariner elements have been described in ants, each one in a different genus of the Myrmicinae subfamily: Sinvmar was isolated from various Solenopsis species, Myrmar from Myrmica ruginodis, and Mboumar from Messor bouvieri. In this study, we report the coexistence of three mariner elements ( Tnigmar- Si, Tnigmar- Mr, and Tnigmar- Mb) in the genome of a single species, Tapinoma nigerrimum (subfamily Dolichoderinae). Molecular evolutionary analyses of the nucleotide sequence data revealed a general agreement between the evolutionary history of most the elements and the ant species that harbour them, and suggest that they are at the vertical inactivation stage of the so-called Mariner Life Cycle. In contrast, significantly reduced levels of synonymous divergence between Mboumar and Tnigmar- Mb and between Myrmar and Botmar (a mariner element isolated from Bombus terrestris), relative to those observed between their hosts, suggest that these elements arrived to the species that host them by horizontal transfer, long after the species' split. The horizontal transfer events for the two pairs of elements could be roughly dated within the last 2 million years and about 14 million years, respectively. As would be expected under this scenario, the coding sequences of the youngest elements, Tnigmar- Mb and Mboumar, are intact and, thus, potentially functional. Each mariner element has a different chromosomal distribution pattern according to their stage within the Mariner Life Cycle. Finally, a new defective transposable element ( Azteca) has also been found inserted into the Tnigmar- Mr sequences showing that the ant genomes have been invaded by at least four different types of mariner elements.

  15. The influence of multiple chemical and non-chemical stressors on benthic communities in a mid-west agricultural stream.

    Science.gov (United States)

    Hall, Lenwood W; Killen, Willian D; Anderson, Ronald D; Alden, Raymond W

    2017-08-24

    The objective of this 3-year study was to characterize benthic communities and physical habitat in an agricultural stream in the mid-west area of the United States (Big Bureau Creek, Illinois). Concurrent basic water quality parameters and seven nutrients were measured in the water column. Sediment measurements from depositional areas were conducted for bifenthrin, Total Organic Carbon, grain size, polychlorinated biphenyls (PCBs) and eight metals. All parameters were measured at 12 sites annually during the late summer for a 3-year period (2014, 2015 and 2016). Univariate regressions, stepwise multiple regressions and canonical correlation statistical analyses were used to determine the relationship between various benthic metrics (i.e., taxa richness and abundance) and all the measured parameters for the 3-year database. Benthic communities comprising 108-110 taxa were collected annually, and were generally dominated by sensitive caddisflies and mayflies. These communities were rated as good to exceptional using the Ohio Invertebrate Community Index. Physical habitat for the various sites was rated as good using the Ohio Qualitative Habitat Evaluation Index, thus suggesting that habitat is not a significant stressor that would likely impact resident benthic communities. Based on a comparison of measured in-stream total nitrogen and total phosphorus concentrations and criterion value exceedances, it appears that the in-stream nutrient concentrations could be potentially stressful to resident benthic biota. Metal concentrations were below established NOAA Threshold Effects Levels at all sites. Measured PCB concentrations were below levels of detection at all sites. Toxic units' (TUs) calculations based on using sensitive laboratory strains of Hyalella were less than 0.1 for bifenthrin, thus suggesting that bifenthrin sediment toxicity was unlikely. Thirty significant relationships reported between benthic metrics and the various environmental variables based on the

  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?

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    Krieger Jakob

    2010-09-01

    suggest that B. latro has visual and mechanosensory skills that are comparable to those of marine Crustacea. Conclusions In parallel to previous behavioral findings that B. latro has aerial olfaction, our results indicate that their central olfactory pathway is indeed most prominent. Similar findings from the closely related terrestrial hermit crab Coenobita clypeatus suggest that in Coenobitidae, olfaction is a major sensory modality processed by the brain, and that for these animals, exploring the olfactory landscape is vital for survival in their terrestrial habitat. Future studies on terrestrial members of other crustacean taxa such as Isopoda, Amphipoda, Astacida, and Brachyura will shed light on how frequently the establishment of an aerial sense of olfaction evolved in Crustacea during the transition from sea to land. Amounting to ca. 1,000,000, the numbers of interneurons that analyse the olfactory input in B. latro brains surpasses that in other terrestrial arthropods, as e.g. the honeybee Apis mellifera or the moth Manduca sexta, by two orders of magnitude suggesting that B. latro in fact is a land-living arthropod that has devoted a substantial amount of nervous tissue to the sense of smell.

  17. PLANIFICACION FAMILIAR: Un Derecho y una Necesidad

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    Miguel Trias

    1984-09-01

    Full Text Available

    La relación que existe entre el crecimiento poblacional y la situación socio-economica de una región, país o continente es algo que en forma intuitiva y vaga se conoce desde la más
    remota antigüedad. No menos conocido, en cada familia, ha sido el efecto nocivo de una
    reproducción superior a la deseada.
    Se ha necesitado del perfeccionismo de nuestros demógrafos y estadísticos para oscurecer la cuestión debajo y detrás de montañas de datos y de complejas ecuaciones.

    La generalizada y muy frecuente práctica del infanticidio entre tantos pueblos primitivos
    de ayer y de hoy, demuestra que a pesar de la elevada mortalidad natural, uno de los pocos insumos sobrantes del que se puede, cuando no se debe, disponer con facilidad es la vida humana acabada de nacer. Los superficiales ritos propiciatorios utilizados en algunos
    casos para su eliminación, le dan un escaso barniz religioso a la profunda preocupación
    ecológica y por consiguiente demográfica que los subyace.

    El infanticidio por simple abandono, practicado sin reatos de conciencia en la China Imperial el Imperio Romano o la Inglaterra pre-victoriana tenia una clara etiología social y económica. Los multitudinarios sacrificios juveniles de los Aztecas en un altiplano altamente erosionado por sobrecultivo, como el que encontraron los españoles a su llegada, parece no tener otra explicación razonable que el de ser una desesperada solución a un grave desequilibrio ecológico. Un desequilibrio que corrigió rápidamente la mortalidad mucho más eficiente que introducir los microbios europeos transportados por los conquistadores...

  18. La actividad físico-deportiva, una práctica educativa en Mesoamérica

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    Saúl GARCIA BLANCO

    2013-11-01

    Full Text Available Siendo fenómenos genuinos de nuestra época, la educación física y el deporte encuentran sus orígenes en las sociedades más antiguas. Consideradas junto al juego hasta tiempo recientes como actividades triviales, resultan sin embargo imprescindibles si se desea conocer la cultura de las civilizaciones pretéritas; ya que estas acciones excepcionales del comportamiento humano, formaban parte de la vida y costumbres de aquellos pueblos. El presente estudio pretende una aproximación a la cultura mesomamericana, incidiendo en el análisis de uno de sus aspectos menos conocido: el conjunto de actividades de carácter físico y lúdico que los pueblos nahua practicaban cotidianamente. Tanto en el ámbito familiar como en el estatal, existía un elevado interés por parte de los padres y educadores hacia la formación física de sus jóvenes. Los hábitos higiénicos inculcados desde las edades más tempranas, favorecían el desarrollo de un organismo fuerte y sano. Los juegos y juguetes potenciaban el desarrollo armónico de los niños. La de mayores, los mexica gustaban de practicar diversos juegos y deportes, destacando el PATOLLI entre los primeros, y siendo el Juego de Pelota (ULLAMALIZTLI el deporte nacional de toda Mesoamérica. Los variados ejercicios físico-deportivos impartido en los Telpochcalli y Calmecac, potenciaban la formación de soldados excepcionales; a la vez que este agrupamiento de jóvenes para una vida en común, donde se sometían a un rígido entrenamiento por medio de ejercicios físicos, estableció el paso de la sociedad azteca de primitiva a nacional; claro ejemplo de lo que Ortega y Gasset definió como «el origen deportivo del Estado.

  19. Gracias a Dios que coamí. Los orígenes del cristianismo en Iberoamérica y El Caribe, siglos XV-XX

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    EDUARDO HOORNAERT

    2011-10-01

    Full Text Available Desde o momento em que Maximiliano Salinas publicou sua Historia del pueblo de Dios en Chile em 1987, ele inova em termos de pesquisa sobre temas que tradicionalmente caem fora do campo de visao do historiador cristao. A inovaçao de 1987 visava aspectos heurísticos, pois mencionado livro partia de folhetos populares, cânticos, benditos, refroes, poesias. Com seu mais novo ensaio, Gracias a Dios que comí, Maximiliano Salinas completa o trabalho heurístico anterior por importantes inovaçoes no campo hermenéutico. O ensaio apresenta o painel de um cristianismo pouco analisado na literatura mas intensamente praticado por descendentes de indígenas, africanos mas também portugueses (fértil fronteira com o Islam. Ele insiste na positividade das culturas que encaram a Deus como fonte da subsistencia, quem nos dá o pao para comer, as pernas para dançar, o ânimo para transformar o trabalho em festa. Ele fala de um Deus cristao dionisíaco. Trata-se de uma inusitada memória crista, e apagada nos textos ortodoxos do cristianismo histórico relegada ao mundo dos textos apócrifos, mas que encontra fortes concordâncias nas culturas azteca, quechua e mapuche onde se vive o trabalho como festa, onde Deus tem maos (para trabalhar e entranhas (para compartir, onde a comida é uma hierofania (as comidas sagradas e o paraíso um deleite culinário. Aí Deus nao é mais o 'preceptor absoluto' mas o 'poeta' (no sentido original: quem faz, quem executa a obra. Postula-se dessa maneira uma releitura global do cristianismo, na linha do livro Dionisios, reíz de la vida indestructible, da autoria de K. Kerényi (Barcelona 1998: «La cultura mediterránea del vino fue el fondo común y concreto de diversos elementos, tales como la fundación del cristianismo...». O Apolo da ciência, o Pluto da riqueza e o Mercúrio do comercio cedem lugar ao Dioniso davida. A partir da vida rejeita-se o 'blanco perfecto', que se manifesta no ‘preceptor exclusivo’ no

  20. El "otro" México del exilio republicano: la visión de José Lion Depetre y La tragedia de Méjico (1954

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    Luis ARIAS GONZÁLEZ

    2010-02-01

    Full Text Available RESUMEN: Los exiliados españoles de la Guerra Civil acogidos generosamente en México, se encontraron con un país muy diferente al esperado; muy pocos se atrevieron, sin embargo, a expresar sus críticas de forma pública. José Lión Depetre, diplomático fiel a la República, vuelve a España en 1953 y publica un libro al año siguiente haciéndose portavoz de estas críticas y recogiendo una visión peculiar sobre la nación azteca. El artículo analiza esta obra, sus motivaciones y la compleja personalidad del autor exponente de un sector poco considerado del exilio: el de los intelectuales retornados, así como las repercusiones que tuvo la aparición de este ensayo en la España de Franco y en la España trasterrada. Palabras clave: Exilio republicano, México, Lázaro Cárdenas, José Lion Depetre, intelectualidad republicana, retornados, Ministerio de Asuntos Exteriores, Martín Artajo. ABSTRACT: The Spanish exiles from the Civil War who were generously welcomed in México, encountered a country very different from what they expected. However, very few of them dare to express their opinions in public. José Lión Depetre, a diplomat loyal to the Spanish Republic, returned to Spain in 1953 and published a book the following year in which he took on the role as a spokesman for those criticisms and expressed a very peculiar view about the aztec nation. This article analises his work, its motivation and the author´s complex personality who is a clear example of a sector of the exiles which has attracted little attention: that of the returned intellectuals, as well as the consequences that the essay had on the Spain under Franco and on the Spanish exiles in general. Keywords: Republican exile, Mexico, Lázaro Cárdenas, José Lión Depetre, republican intellectuals, returned exiles, Foreign Office, Martín Artajo.

  1. Ideas de Vida y Muerte en Antiguas Culturas de Mesoamérica.

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    Adolfo de Francisco Zea

    1998-12-01

    Full Text Available

    (Trabajo presentado a la Academia Nacional de Medicina el 5 de diciembre de 1996

    En el mes de abril de 1519, Hernán Cortés a la cabeza de un grupo de 553 hombres, desembarcó de sus once pequeños navíos, el más grande de los cuales desplazaba apenas cien toneladas, en la costa del golfo de México a la altura de lo que hoy se conoce como la isla de Cozumel, frente a la península de Yucatán. Cuatro meses más tarde, después de haber recorrido la costa occidental del Caribe mexicano, Cortés dio comienzo a una de las aventuras más increíbles del siglo XVI, que habría de terminar dos años más tarde con la derrota del imperio azteca y la destrucción de su capital, Tenochtitlán, por aquel entonces la ciudad más populosa de toda mesoamérica. Antes de iniciar el16 de agosto de 1519 su expedición al interior del territorio mexicano, Cortés quemó los cascos de diez de sus naves, dejando solamente una en reserva que le podría permitir ponerse en contacto con Cuba, Santo Domingo y eventualmente España, si fuere necesario.

    Tuvo sin embargo el cuidado, al desmantelar las embarcaciones, de ocultar los velámenes, las anclas, los clavos y demás elementos de hierro que posteriormente habrían de servirle en la construcción de los bergantines de guerra que en el lago de Texcoco le permitieron el asedio final a Tenochtitlán. Tenochtitlán, la capital del imperio azteca había sido fundada en 1315 por tribus nómadas venidas del norte, de la región de Aztlán o “país de las garzas”, que se asentaron en las regiones lacustres del altiplano central de México, cuando después de un largo peregrinar encontraron como signo promisorio a un águila, que parada en una planta de nopal devoraba una serpiente.

    En sus leyendas, ése era el signo que su dios tribal del Sol y de la guerra, Huitschilopotl, les había señalado para identificar el sitio donde debían finalmente establecerse. Durante los dos

  2. Impacto de la producción lechera en la calidad de los cuerpos de agua

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    Rafael Arocena

    2013-10-01

    Hyalella y Caenidae, indicadores de contaminación moderada-, mostró diferencias en relación al grado de impacto. Los arroyos con menor actividad lechera en sus cuencas mostraron la mayor diversidad. El embalse presentó una alta biodisponibilidad de nutrientes pero no un crecimiento excesivo del fitoplancton, cuya abundancia fue en general baja y no se registraron floraciones algales nocivas. La conductividad fue baja, el pH levemente alcalino y el oxígeno disuelto en general alto. La composición planctónica varió temporal y espacialmente, pero en general en la cola del embalse dominaron las diatomeas, en dos brazos receptores de cuencas lecheras y en la cabecera las cianobacterias y en otros dos brazos las euglenofitas y crisofitas. El zooplancton estuvo compuesto por rotíferos (45%, copépodos (36%, el molusco invasor Limnoperna fortunei (11% y cladóceros (8%.

  3. Cultural heritage and food identity: The pre-Hispanic salt of Zapotitlán Salinas, Mexico

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    Renard, Marie-Christine

    2016-06-01

    Full Text Available Salt production in Zapotitlán de las Salinas (Puebla, Mexico dates back to pre-Hispanic times when the Popolocas inhabiting the Tehuacán Valley paid it as tribute to the Aztecs. The technique to obtain salt has changed little over the past 500 years and know-how continues to be transmitted from generation to generation of salters (salineros. It is a resource that is deeply anchored in the identity of the inhabitants of Zapotitlán and regional cuisine. Salt has endured over the centuries as a perennial resource and constitutes a source of income for its owners. However, despite these historical and cultural factors of territorial anchorage, salters have not attained the level of organization necessary to obtain a fair value in the market. Failure to appreciate this product has led to the abandonment of a large percentage of the saltworks that once existed. This essay will analyze the socio-economic and cultural constraints that have prevented this community from attaining the level of territorial governance necessary to enhance the market value of Zapotitlán salt on the market but how, with the depletion of other economic options, its people are returning to the salt, with new strategies. Lastly, the paper will conclude with a consideration of its future potential.La producción de sal de Zapotitlán de las Salinas (Puebla, México se remonta a épocas prehispánicas cuando los popolocas, moradores del valle de Tehuacán, lo tributaban a los aztecas. La técnica para la obtención de la sal ha cambiado poco desde hace 500 años y el saber-hacer se sigue transmitiendo entre las generaciones de salineros. Es un recurso profundamente anclado en la identidad de los habitantes de Zapotitlán y en la gastronomía regional. Su existencia ha perdurado en el transcurso de los siglos por ser un recurso perenne y constituir una renta para sus dueños. Sin embargo, a pesar de los factores históricos y culturales de anclaje territorial, los salineros no

  4. Un acercamiento a las modificaciones del medio físico latinoamericano durante la colonización: consideraciones generales y algunos ejemplos en las montañas tropicales

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    1987-01-01

    Full Text Available Les montagnes tropicales se caractérisent par une grande variété de paliers écologiques dont l'homme a su tirer profit et les altitudes élevées n'ont jamais opposé de limite à l'action anthropique. Durant les derniers millénaires, les oscillations climatiques entre la sécheresse et l'humidité ont contraint les groupes humains à se déplacer ou s'adapter à ces nouvelles conditions et à modifier leurs techniques. Les travaux de Murra ont mis en évidence un modèle vertical d'utilisation d'un nombre maximal de paliers écologiques dans leur complémentarité à une autre échelle, les civilisations inca et aztèque, grâce à un système politico-social puissant, ont réussi à établir leur empire dans un cadre physique hétérogène et difficile. Le colonisateur européen, lui, a ignoré toutes ces formes d'adaptation précolombiennes. Le développement urbain, la concentration d'une population déjà réduite par la conquête, l'introduction de l'élevage ovin et bovin, la modification des techniques agricoles, la multiplication des chemins muletiers et l'exploitation des mines introduisirent autant de changements dans l'environnement écologique -coupe des arbres, diverses formes d'érosion- dont le bilan reste encore à évaluer compte tenu du nombre relativement faible d'études réalisées sur ce thème. Las montañas tropicales se caracterizan por la gran variedad de los pisos ecológicos que el hombre supo aprovechar y la altura elevada nunca fue una limitación a la acción antrópica. Durante los últimos milenios, las oscilaciones climáticas entre sequía y humedad obligaron a los grupos humanos a desplazarse o adaptarse, modificando sus técnicas. Los trabajos de Murra evidenciaron, en los Andes, un modelo vertical de uso de un máximo de pisos ecológicos en su complementariedad a otra escala, las civilizaciones inca y azteca, con un sistema político-social potente, lograron establecer imperios en un marco físico muy

  5. Distribución espacial de Cordyceps spp. (Ascomycotina: Clavicipitaceae y su impacto sobre las hormigas en selvas del piedemonte amazónico de Colombia

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    Sanjuán Tatiana

    2001-12-01

    Full Text Available Se estudió la diversidad del género Cordyceps, hongo entomopatógeno, en hormigas del piedemonte Amazónico colombiano (450-600 msnm, enero y mayo de 1998, épocas seca y lluviosa, respectivamente. La recolección de hormigas sanas y parasitadas por Cordyceps se llevó a cabo en tres bosques con distintos regímenes de perturbación: natural, antrópico y poco perturbado. Se establecieron 100 cuadrantes de 1 m² por cada bosque. Las muestras fueron tomadas en hojarasca, arbustos y troncos como sustratos, y cada 50 cm hasta 2 m de altura los estratos verticales. El género Azteca fue el predominante en el bosque poco perturbado, mientras Camponotus, Pheidole y Crematogaster abundaron en los bosques con perturbación natural y antrópica. El bosque con perturbación natural presentó 759 individuos de C. unilateralis y 69 de C. lloydii var. binata parasitando hormigas Camponotus spp. (Formicidae: Formicinae. Se encontraron sólo seis casos de C. kniphofioides var. ponerinarum y C. australis en las hormigas Paraponera clavata y Pachycondyla crassinoda (Formicidae: Ponerinae. En el bosque perturbado antrópicamente se presentaron 34 ejemplares de C. unilateralis en Camponotus mientras que en el menos perturbado no se observaron hormigas parasitadas. Se halló que las hormigas Camponotus spp. que son parasitadas por C. unilateralis y C. lloydii var. binata se ubican preferencialmente en el sustrato hoja, hasta 1 m de altura. Se determinó que la incidencia de la interacción Cordyceps / hormiga no está influenciada por el estado de conservación del bosque, sin embargo, la variación de la humedad relativa y la presencia o ausencia de la hormiga hospedera son factores que influyen en la diversidad de Cordyceps en hormigas. Se encontró, además, que la distribución microespacial de la interacción sigue un patrón determinado, aportando más argumentos a la hipótesis de que los mecanismos de dispersión de Cordyceps coevolucionaron con la

  6. Liquidambar para produção de madeira no sul e sudeste do Brasil Sweetgum for wood production in the South and Southeastern Brazil

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    Jarbas Yukio Shimizu

    2011-03-01

    Full Text Available O liquidambar é uma espécie de ampla distribuição natural, abrangendo as regiões leste e sudeste dos  Estados Unidos, avançando para o sul, pelo México, até América Central. As propriedades medicinais de sua seiva são conhecidas desde a época da civilização Azteca. Nos Estados Unidos, esta é a espécie folhosa de maior área plantada para fins de produção de  madeira. Ela cresce bem em diversos tipos de solo,  inclusive em aluviões sujeitos a inundações. Uma  conseqüência da extensão da sua área de distribuição  natural é a ampla variação nos caracteres fenológicos e de crescimento observada em plantios. As procedências mais do norte tendem a cessar os  processos de crescimento mais cedo e a iniciar mais tardiamente do que as do sul. Essas variações refletem, diretamente, no padrão de crescimento entre as diferentes origens  da semente. Experimentos em vários sítios têm  demonstrado o seu alto potencial para produção de  madeira nas pequenas propriedades rurais brasileiras.  As procedências mais do sul (América Central  demonstraram maior produtividade do que as da  América do Norte; as procedências mais promissoras  apresentaram produtividade semelhante à dos  eucaliptos de rápido crescimento, da ordem de 40  m3/ha.ano. Sua madeira é indicada para múltiplos  usos como matéria-prima para celulose, dormentes,  madeira serrada para embalagens, estrados, móveis e até como lenha. Porém, um de seus usos mais  valorizados é o na produção de lâminas para chapas compensadas. No entanto, o seu cultivo deve ser acompanhado de cuidados especiais devido à natureza  invasiva desta espécie. No Brasil, ela produz grande  quantidade de semente, com grande probabilidade de germinar e se estabelecer espontaneamente no  terreno. Um fator decisivo para esta ameaça é a  ausência de predadores naturais como pássaros e  roedores que, na sua área de ocorrência natural,  coexistem em