Size-dependent effects of low level cadmium and zinc exposure on the metabolome of the Asian clam, Corbicula fluminea

International Nuclear Information System (INIS)

Spann, Nicole; Aldridge, David C.; Griffin, Julian L.; Jones, Oliver A.H.

2011-01-01

Highlights: Small and large Corbicula fluminea were exposed to cadmium and zinc spiked sediment. Metabolomic changes in the freshwater clams were determined by NMR and GC–MS. Metabolic perturbations were related to amino acid and energy related metabolism. Small and large clams were differentiated by their metabolic composition. Size classes showed opposite responses to metal stress. - Abstract: The toxic effects of low level metal contamination in sediments are currently poorly understood. We exposed different sized Asian clams, Corbicula fluminea, to sediment spiked with environmentally relevant concentrations of either zinc, cadmium or a zinc–cadmium mixture for one week. This freshwater bivalve is well suited for sediment toxicity tests as it lives partly buried in the sediment and utilises sediment particles as a food resource. After one week, the whole tissue composition of low molecular weight metabolites was analysed by nuclear magnetic resonance spectroscopy (NMR) and gas chromatography–mass spectrometry (GC–MS). The condition index (ratio of tissue dry weight to volume inside the shell valves) was also measured. Small and large clams were clearly differentiated by their metabolic composition and the two size classes showed opposite responses to the mixture spiked sediment. No effects of zinc alone on the metabolome were found and cadmium only influenced the smaller size class. The main perturbations were seen in amino acid and energy metabolism, with small clams using amino acids as an energy resource and larger clams primarily drawing on their larger storage reserves of carbohydrates. Our study demonstrates that metabolomics is a useful technique to test for low level toxicity which does not manifest in mortality or condition index changes. The differing effects between the two size classes stress that it is important to consider age/size when conducting metabolomic and ecotoxicology assessments, since testing for the effects on only one size

Size-dependent effects of low level cadmium and zinc exposure on the metabolome of the Asian clam, Corbicula fluminea

Energy Technology Data Exchange (ETDEWEB)

Spann, Nicole, E-mail: nicole.spann@web.de [Department of Zoology, University of Cambridge, Downing Street, Cambridge CB2 3EJ (United Kingdom); Aldridge, David C., E-mail: da113@cam.ac.uk [Department of Zoology, University of Cambridge, Downing Street, Cambridge CB2 3EJ (United Kingdom); Griffin, Julian L., E-mail: jlg40@mole.bio.cam.ac.uk [Sanger Building, Department of Biochemistry, University of Cambridge, 80 Tennis Court Road, Cambridge CB2 1GA (United Kingdom); Jones, Oliver A.H., E-mail: o.jones@gmail.com [Sanger Building, Department of Biochemistry, University of Cambridge, 80 Tennis Court Road, Cambridge CB2 1GA (United Kingdom)

2011-10-15

Highlights: Small and large Corbicula fluminea were exposed to cadmium and zinc spiked sediment. Metabolomic changes in the freshwater clams were determined by NMR and GC-MS. Metabolic perturbations were related to amino acid and energy related metabolism. Small and large clams were differentiated by their metabolic composition. Size classes showed opposite responses to metal stress. - Abstract: The toxic effects of low level metal contamination in sediments are currently poorly understood. We exposed different sized Asian clams, Corbicula fluminea, to sediment spiked with environmentally relevant concentrations of either zinc, cadmium or a zinc-cadmium mixture for one week. This freshwater bivalve is well suited for sediment toxicity tests as it lives partly buried in the sediment and utilises sediment particles as a food resource. After one week, the whole tissue composition of low molecular weight metabolites was analysed by nuclear magnetic resonance spectroscopy (NMR) and gas chromatography-mass spectrometry (GC-MS). The condition index (ratio of tissue dry weight to volume inside the shell valves) was also measured. Small and large clams were clearly differentiated by their metabolic composition and the two size classes showed opposite responses to the mixture spiked sediment. No effects of zinc alone on the metabolome were found and cadmium only influenced the smaller size class. The main perturbations were seen in amino acid and energy metabolism, with small clams using amino acids as an energy resource and larger clams primarily drawing on their larger storage reserves of carbohydrates. Our study demonstrates that metabolomics is a useful technique to test for low level toxicity which does not manifest in mortality or condition index changes. The differing effects between the two size classes stress that it is important to consider age/size when conducting metabolomic and ecotoxicology assessments, since testing for the effects on only one size class makes

Rare earth elements in the aragonitic shell of freshwater mussel Corbicula fluminea and the bioavailability of anthropogenic lanthanum, samarium and gadolinium in river water

International Nuclear Information System (INIS)

Merschel, Gila; Bau, Michael

2015-01-01

High-technology metals — such as the rare earth elements (REE) — have become emerging contaminants in the hydrosphere, yet little is known about their bioavailability. The Rhine River and the Weser River in Germany are two prime examples of rivers that are subjected to anthropogenic REE input. While both rivers carry significant loads of anthropogenic Gd, originating from contrast agents used for magnetic resonance imaging, the Rhine River also carries large amounts of anthropogenic La and lately Sm which are discharged into the river from an industrial point source. Here, we assess the bioavailability of these anthropogenic microcontaminants in these rivers by analyzing the aragonitic shells of the freshwater bivalve Corbicula fluminea. Concentrations of purely geogenic REE in shells of comparable size cover a wide range of about one order of magnitude between different sampling sites. At a given sampling site, geogenic REE concentrations depend on shell size, i.e. mussel age. Although both rivers show large positive Gd anomalies in their dissolved loads, no anomalous enrichment of Gd relative to the geogenic REE can be observed in any of the analyzed shells. This indicates that the speciations of geogenic and anthropogenic Gd in the river water differ from each other and that the geogenic, but not the anthropogenic Gd is incorporated into the shells. In contrast, all shells sampled at sites downstream of the industrial point source of anthropogenic La and Sm in the Rhine River show positive La and Sm anomalies, revealing that these anthropogenic REE are bioavailable. Only little is known about the effects of long-term exposure to dissolved REE and their general ecotoxicity, but considering that anthropogenic Gd and even La have already been identified in German tap water and that anthropogenic La and Sm are bioavailable, this should be monitored and investigated further. - Highlights: • Corbicula fluminea shells are bioarchives of dissolved geogenic REE in

Rare earth elements in the aragonitic shell of freshwater mussel Corbicula fluminea and the bioavailability of anthropogenic lanthanum, samarium and gadolinium in river water

Energy Technology Data Exchange (ETDEWEB)

Merschel, Gila, E-mail: g.merschel@jacobs-university.de; Bau, Michael

2015-11-15

High-technology metals — such as the rare earth elements (REE) — have become emerging contaminants in the hydrosphere, yet little is known about their bioavailability. The Rhine River and the Weser River in Germany are two prime examples of rivers that are subjected to anthropogenic REE input. While both rivers carry significant loads of anthropogenic Gd, originating from contrast agents used for magnetic resonance imaging, the Rhine River also carries large amounts of anthropogenic La and lately Sm which are discharged into the river from an industrial point source. Here, we assess the bioavailability of these anthropogenic microcontaminants in these rivers by analyzing the aragonitic shells of the freshwater bivalve Corbicula fluminea. Concentrations of purely geogenic REE in shells of comparable size cover a wide range of about one order of magnitude between different sampling sites. At a given sampling site, geogenic REE concentrations depend on shell size, i.e. mussel age. Although both rivers show large positive Gd anomalies in their dissolved loads, no anomalous enrichment of Gd relative to the geogenic REE can be observed in any of the analyzed shells. This indicates that the speciations of geogenic and anthropogenic Gd in the river water differ from each other and that the geogenic, but not the anthropogenic Gd is incorporated into the shells. In contrast, all shells sampled at sites downstream of the industrial point source of anthropogenic La and Sm in the Rhine River show positive La and Sm anomalies, revealing that these anthropogenic REE are bioavailable. Only little is known about the effects of long-term exposure to dissolved REE and their general ecotoxicity, but considering that anthropogenic Gd and even La have already been identified in German tap water and that anthropogenic La and Sm are bioavailable, this should be monitored and investigated further. - Highlights: • Corbicula fluminea shells are bioarchives of dissolved geogenic REE in

Invasive zebra mussels (Driessena polymorpha) and Asian clams (Corbicula fluminea) survive gut passage of migratory fish species: implications for dispersal

Science.gov (United States)

Gatlin, Michael R.; Shoup, Daniel E.; Long, James M.

2013-01-01

The introduction and spread of invasive species is of great concern to natural resource managers in the United States. To effectively control the spread of these species, managers must be aware of the multitude of dispersal methods used by the organisms. We investigated the potential for survival through the gut of a migrating fish (blue catfish, Ictalurus furcatus) as a dispersal mechanism for two invasive bivalves: zebra mussel (Driessena polymorpha) and Asian clam (Corbicula fluminea). Blue catfish (N = 62) were sampled over several months from Sooner Lake, Oklahoma, transported to a laboratory and held in individual tanks for 48 h. All fecal material was collected and inspected for live mussels. Survival was significantly related to water temperature in the lake at the time of collection, with no mussels surviving above 21.1 C°, whereas 12 % of zebra mussels (N = 939) and 39 % of Asian clams (N = 408) consumed in cooler water survived gut passage. This research demonstrates the potential for blue catfish to serve as a dispersal vector for invasive bivalves at low water temperatures.

Light and scanning electron microscopic studies of Unionicola tetrafurcatus (Acari: Unionicolidae) infecting four freshwater bivalve species with referring to histopathological effect on its hosts.

Science.gov (United States)

Abdel-Gaber, Rewaida; Fol, Mona; Al Quraishy, Saleh

2018-05-08

Water mites of the genus Unionicola are the most common symbionts of freshwater bivalves. During the current investigation, a total of 120 live freshwater mussels [Corbicula fluminea (Veneroida), Coelatura aegyptiaca (Unionoidea) Mutela rostrata and Chambardia rubens (Mutelidae)], were collected from 2 localities in Tura (Helwan Governorate) and El Kanater (Qaluobiya Governorate), Egypt. Only 3 of the 4 bivalve species listed are considered freshwater bivalves (members of Unionoidea). While, C. fluminea belong to the family Cyrenidae within Veneroida. The collected mussels were dissected and examined for the presence of unionicolid mites. It was found that 30.83% (37/120) were infected with a single mite species Unionicola tetrafurcatus (Unionicolidae). The highest prevalence was observed during the summer with 83.33% (25/30), whereas the least was observed in autumn, i.e. 33.33% (10/30). Mites were recovered from the gills, gonads, and visceral mass of mussel hosts. gills of host mussels were the primary site of oviposition for unionicola mites. Smaller bivalves in size had significantly greater numbers of mites than larger ones in size. Numbers of mites per host species was variable and the highest prevalence level of 83.33% (25/30) was recorded in C. fluminea, while, the lowest one of 16.66% (5/30) was found in C. rubens. Morphological and morphometric characterizations of mites revealed some differences between the present species and other related Unionicola. Histopathological responses of host mussels to the eggs, larvae, and cuticular remnants of U. tetrafurcatus were also studied. Therefore, the present study demonstrated that freshwater bivalves have a new host and locality records for infection with U. tetrafurcatus. Future studies are recommended to include advanced molecular characteristics for these mites.

Risk-based approach to appraise valve closure in the clam Corbicula fluminea in response to waterborne metals

International Nuclear Information System (INIS)

Liao, C.-M.; Jou, L.-J.; Chen, B.-C.

2005-01-01

We developed a risk-based approach to assess how the valve closure behavior of Asiatic clam Corbicula fluminea responds to waterborne copper (Cu) and cadmium (Cd). We reanalyzed the valve closure response data from published literature to reconstruct the response time-dependent dose-response profiles based on an empirical three-parameter Hill equation model. We integrated probabilistic exposure profiles of measured environmental Cu and Cd concentrations in the western coastal areas of Taiwan with the reconstructed dose-response relationships at different integration times of response to quantitatively estimate the valve response risk. The risk assessment results implicate exposure to waterborne Cu and Cd may pose no significant risk to clam valve activity in the short-time response periods (e.g., <30 min), yet a relative high risk for valve closure response to waterborne Cu at response times greater than 120 min is alarming. We successfully linked reconstructed dose-response profiles and EC50-time relationships associated with the fitted daily valve opening/closing rhythm characterized by a three-parameter lognormal function to predict the time-varying bivalve closure rhythm response to waterborne metals. We parameterized the proposed predictive model that should encourage a risk-management framework for discussion of future design of biological monitoring systems. - A model was developed to link valve closure in clams to concentrations of metals in water

Direct and indirect effects of different types of microplastics on freshwater prey (Corbicula fluminea) and their predator (Acipenser transmontanus)

Science.gov (United States)

Parnis, J. Mark; Browne, Mark A.; Serrato, Sebastian; Reiner, Eric J.; Robson, Matthew; Young, Thomas; Diamond, Miriam L.; Teh, Swee J.

2017-01-01

We examined whether environmentally relevant concentrations of different types of microplastics, with or without PCBs, directly affect freshwater prey and indirectly affect their predators. Asian clams (Corbicula fluminea) were exposed to environmentally relevant concentrations of polyethylene terephthalate (PET), polyethylene, polyvinylchloride (PVC) or polystyrene with and without polychlorinated biphenyls (PCBs) for 28 days. Their predators, white sturgeon (Acipenser transmontanus), were exposed to clams from each treatment for 28 days. In both species, we examined bioaccumulation of PCBs and effects (i.e., immunohistochemistry, histology, behavior, condition, mortality) across several levels of biological organization. PCBs were not detected in prey or predator, and thus differences in bioaccumulation of PCBs among polymers and biomagnification in predators could not be measured. One of the main objectives of this study was to test the hypothesis that bioaccumulation of PCBs would differ among polymer types. Because we could not answer this question experimentally, a bioaccumulation model was run and predicted that concentrations of PCBs in clams exposed to polyethylene and polystyrene would be greater than PET and PVC. Observed effects, although subtle, seemed to be due to microplastics rather than PCBs alone. For example, histopathology showed tubular dilation in clams exposed to microplastics with PCBs, with only mild effects in clams exposed to PCBs alone. PMID:29108004

Direct and indirect effects of different types of microplastics on freshwater prey (Corbicula fluminea and their predator (Acipenser transmontanus.

Directory of Open Access Journals (Sweden)

Chelsea M Rochman

Full Text Available We examined whether environmentally relevant concentrations of different types of microplastics, with or without PCBs, directly affect freshwater prey and indirectly affect their predators. Asian clams (Corbicula fluminea were exposed to environmentally relevant concentrations of polyethylene terephthalate (PET, polyethylene, polyvinylchloride (PVC or polystyrene with and without polychlorinated biphenyls (PCBs for 28 days. Their predators, white sturgeon (Acipenser transmontanus, were exposed to clams from each treatment for 28 days. In both species, we examined bioaccumulation of PCBs and effects (i.e., immunohistochemistry, histology, behavior, condition, mortality across several levels of biological organization. PCBs were not detected in prey or predator, and thus differences in bioaccumulation of PCBs among polymers and biomagnification in predators could not be measured. One of the main objectives of this study was to test the hypothesis that bioaccumulation of PCBs would differ among polymer types. Because we could not answer this question experimentally, a bioaccumulation model was run and predicted that concentrations of PCBs in clams exposed to polyethylene and polystyrene would be greater than PET and PVC. Observed effects, although subtle, seemed to be due to microplastics rather than PCBs alone. For example, histopathology showed tubular dilation in clams exposed to microplastics with PCBs, with only mild effects in clams exposed to PCBs alone.

Bioavailability and toxicity of metals from a contaminated sediment by acid mine drainage: linking exposure-response relationships of the freshwater bivalve Corbicula fluminea to contaminated sediment.

Science.gov (United States)

Sarmiento, Aguasanta M; Bonnail, Estefanía; Nieto, José Miguel; DelValls, Ángel

2016-11-01

Streams and rivers strongly affected by acid mine drainage (AMD) have legal vacuum in terms of assessing the water toxicity, since the use of conventional environmental quality biomarkers is not possible due to the absence of macroinvertebrate organisms. The Asian clam Corbicula fluminea has been widely used as a biomonitor of metal contamination by AMD in freshwater systems. However, these clams are considered an invasive species in Spain and the transplantation in the field study is not allowed by the Environmental Protection Agency. To evaluate the use of the freshwater bivalve C. fluminea as a potential biomonitor for sediments contaminated by AMD, the metal bioavailability and toxicity were investigated in laboratory by exposure of clams to polluted sediments for 14 days. The studied sediments were classified as slightly contaminated with As, Cr, and Ni; moderately contaminated with Co; considerably contaminated with Pb; and heavily contaminated with Cd, Zn, and specially Cu, being reported as very toxic to Microtox. On the fourth day of the exposure, the clams exhibited an increase in concentration of Ga, Ba, Sb, and Bi (more than 100 %), followed by Co, Ni, and Pb (more than 60 %). After the fourth day, a decrease in concentration was observed for almost all metals studied except Ni. An allometric function was used to determine the relationship between the increases in metal concentration in soft tissue and the increasing bioavailable metal concentrations in sediments.

Assessment of Lemna minor (duckweed) and Corbicula fluminea (freshwater clam) as potential indicators of contaminated aquatic ecosystems: responses to presence of psychoactive drug mixtures.

Science.gov (United States)

Bourioug, Mohamed; Mazzitelli, Jean-Yves; Marty, Pierre; Budzinsky, Hélène; Aleya, Lotfi; Bonnafé, Elsa; Geret, Florence

2018-04-01

The pharmaceutical products are emerging pollutants continuously released into the environment, because they cannot be effectively removed by the wastewater treatment plants. In recent years, questions have been raised concerning the environmental risks related to these pollutants. The goal of this research was to evaluate the responses in Lemna minor after 7 days and in Corbicula fluminea after differing durations (1, 3, 7, and 19 days) of exposure to the psychoactive drug mixture (valproic acid, citalopram, carbamazepine, cyamemazine, hydroxyzine, oxazepam, norfluoxetine, lorazepam, fluoxetine, and sertraline) in different concentrations (0, 0 + ethanol, drug concentration (DC) 1 = river water concentration, DC2 = effluent concentration, and DC3 = 10× effluent concentration). In this aim, growth parameters of L. minor, gluthathione S-transferase (GSTs), catalase (CAT), ethoxyresorufin-O-deethylase (EROD) and/or gene expressions (pi-gst, cat, cytochrome P450 4 (cyp4), multidrug resistant 1 (mdr1), and superoxide dismutase (sod)) were measured. GST activities increased significantly in L. minor exposed to DC3, but no changes were found in CAT activity. In C. fluminea, EROD activity was induced significantly in both gill and digestive gland tissues after 3 days' exposure to DC3, while a GST increase was observed only in digestive gland tissues, suggesting that these pharmaceuticals induced an oxidative effect. Gene expression analysis revealed transient transcriptomic responses of cyp4, sod, and mdr1 under drug concentrations 2 or 3 and no change of expression for the other genes (cat and pi-gst) or condition (environmental drug concentration) tested. Finally, the data reported in this study represent important ecotoxicological information, confirming that this enzyme family (cyp4, sod, and mdr1) may be considered as a sensible and early indicator of exposure to drugs and emphasizing the involvement of selected genes in detoxification pathways.

Identification of larvae: The zebra mussel (Dreissena polymorpha), quagga mussel (Dreissena rosteriformis bugensis), and Asian clam (Corbicula fluminea)

Science.gov (United States)

Nichols, S. Jerrine; Black, M.G.

1994-01-01

There are presently four freshwater bivalves in the United States that produce larvae or veligers commonly found in the water column: two forms of Asian clams and two species of dreissenids. Portions of the geographic range of three of these bivalves, one species of Asian clam (Corbicula fluminea), zebra mussels (Dreissena polymorpha), and quagga mussels (Dreissena rosteriformis bugensis), overlap, causing problems with larval identification. To determine which characteristics can be used to separate larval forms, adult Asian clams, quaggas, and zebra mussels were brought into the laboratory and induced to spawn, and the resulting larvae were reared. Hybrids between quaggas and zebra mussels were also produced, but not reared to maturity. Characteristics allowing for the most rapid and accurate separation of larvae were hinge length, shell length/height, shell shape, shell size, and the presence or absence of a foot and velum. These characteristics were observed in laboratory-reared larvae of known parentage and field-caught larvae of unknown parentage. In most cases, larvae of the Asian clam can be readily separated from those produced by either type of dreissenid on the basis of shell size and presence of a foot. Separating the gametes and embryos of the two types of dreissenids is not possible, but after shell formation, most of the larval stages can be distinguished. Hinge length, shell length/height, and the similarity in size of the shell valves can be used to separate straight-hinged, umbonal, pediveliger, and plantigrade larvae. Quagga × zebra mussel hybrids show characteristics of both parents and are difficult to identify.

A novel approach for acid mine drainage pollution biomonitoring using rare earth elements bioaccumulated in the freshwater clam Corbicula fluminea.

Science.gov (United States)

Bonnail, Estefanía; Pérez-López, Rafael; Sarmiento, Aguasanta M; Nieto, José Miguel; DelValls, T Ángel

2017-09-15

Lanthanide series have been used as a record of the water-rock interaction and work as a tool for identifying impacts of acid mine drainage (lixiviate residue derived from sulphide oxidation). The application of North-American Shale Composite-normalized rare earth elements patterns to these minority elements allows determining the origin of the contamination. In the current study, geochemical patterns were applied to rare earth elements bioaccumulated in the soft tissue of the freshwater clam Corbicula fluminea after exposure to different acid mine drainage contaminated environments. Results show significant bioaccumulation of rare earth elements in soft tissue of the clam after 14 days of exposure to acid mine drainage contaminated sediment (ΣREE=1.3-8μg/gdw). Furthermore, it was possible to biomonitor different degrees of contamination based on rare earth elements in tissue. The pattern of this type of contamination describes a particular curve characterized by an enrichment in the middle rare earth elements; a homologous pattern (E MREE =0.90) has also been observed when applied NASC normalization in clam tissues. Results of lanthanides found in clams were contrasted with the paucity of toxicity studies, determining risk caused by light rare earth elements in the Odiel River close to the Estuary. The current study purposes the use of clam as an innovative "bio-tool" for the biogeochemical monitoring of pollution inputs that determines the acid mine drainage networks affection. Copyright © 2017 Elsevier B.V. All rights reserved.

Oxidative stress and histological changes following exposure to diamond nanoparticles in the freshwater Asian clam Corbicula fluminea (Müller, 1774)

International Nuclear Information System (INIS)

Cid, Antonio; Picado, Ana; Correia, José Brito; Chaves, Rúben; Silva, Héber; Caldeira, Jorge; Alves de Matos, António P.

2015-01-01

Highlights: • We assess the toxicity of NDs in the bivalve Corbiculafluminea. • Exposure to NDs cause a stress oxidative response. • Stress oxidative enzymes increase following exposure to nanodiamonds. • Increase in lipid peroxidation suggests damage in cells membranes. • Histopathology reveals alterations in digestive gland cells. - Abstract: Recently, the scientific community became aware of the potential ability of nanoparticles to cause toxicity in living organisms. Therefore, many of the implications for aquatic ecosystems and its effects on living organisms are still to be evaluated and fully understood. In this study, the toxicity of nanodiamonds (NDs) was assessed in the freshwater bivalve (Corbicula fluminea) following exposure to different nominal concentrations of NDs (0.01, 0.1, 1, and 10 mg l −1 ) throughout 14 days. The NDs were characterized (gravimetry, pH, zeta potential, electron microscopy, and atomic force microscopy) confirming manufacturer information and showing NDs with a size of 4–6 nm. Oxidative stress enzymes activities (glutathione-S-transferase, catalase) and lipid peroxidation were determined. The results show a trend to increase in GST activities after seven days of exposure in bivalves exposed to NDs concentrations (>0.1 mg l −1 ), while for catalase a significant increase was found in bivalves exposed from 0.01 to 1.0 mg l −1 following an exposure of 14 days. The histological analysis revealed alterations in digestive gland cells, such as vacuolization and thickening. The lipid peroxidation showed a trend to increase for the different tested NDs concentrations which is compatible with the observed cellular damage

Oxidative stress and histological changes following exposure to diamond nanoparticles in the freshwater Asian clam Corbicula fluminea (Müller, 1774)

Energy Technology Data Exchange (ETDEWEB)

Cid, Antonio [REQUIMTE, Departamento de Química, Faculdade de Ciências e Tecnología, Centro de Química Fina e Biotecnología, Universidade Nova de Lisboa, 2829-516 Caparica (Portugal); Picado, Ana; Correia, José Brito [LNEG-Laboratório Nacional de Energia e Geologia, I.P. Estrada do Paço do Lumiar 22, 1649-038 Lisboa (Portugal); Chaves, Rúben; Silva, Héber [Centro de Investigação Interdisciplinar Egas Moniz, Instituto Superior de Ciências da Saúde Egas Moniz, 2825-511 Caparica (Portugal); Caldeira, Jorge [REQUIMTE, Departamento de Química, Faculdade de Ciências e Tecnología, Centro de Química Fina e Biotecnología, Universidade Nova de Lisboa, 2829-516 Caparica (Portugal); Centro de Investigação Interdisciplinar Egas Moniz, Instituto Superior de Ciências da Saúde Egas Moniz, 2825-511 Caparica (Portugal); Alves de Matos, António P. [Centro de Investigação Interdisciplinar Egas Moniz, Instituto Superior de Ciências da Saúde Egas Moniz, 2825-511 Caparica (Portugal); Centro de Estudos do Ambiente e do Mar (CESAM/FCUL)—Faculdade de Ciências da Universidade de Lisboa, Campo Grande, 1749-016 Lisboa (Portugal); and others

2015-03-02

Highlights: • We assess the toxicity of NDs in the bivalve Corbiculafluminea. • Exposure to NDs cause a stress oxidative response. • Stress oxidative enzymes increase following exposure to nanodiamonds. • Increase in lipid peroxidation suggests damage in cells membranes. • Histopathology reveals alterations in digestive gland cells. - Abstract: Recently, the scientific community became aware of the potential ability of nanoparticles to cause toxicity in living organisms. Therefore, many of the implications for aquatic ecosystems and its effects on living organisms are still to be evaluated and fully understood. In this study, the toxicity of nanodiamonds (NDs) was assessed in the freshwater bivalve (Corbicula fluminea) following exposure to different nominal concentrations of NDs (0.01, 0.1, 1, and 10 mg l{sup −1}) throughout 14 days. The NDs were characterized (gravimetry, pH, zeta potential, electron microscopy, and atomic force microscopy) confirming manufacturer information and showing NDs with a size of 4–6 nm. Oxidative stress enzymes activities (glutathione-S-transferase, catalase) and lipid peroxidation were determined. The results show a trend to increase in GST activities after seven days of exposure in bivalves exposed to NDs concentrations (>0.1 mg l{sup −1}), while for catalase a significant increase was found in bivalves exposed from 0.01 to 1.0 mg l{sup −1} following an exposure of 14 days. The histological analysis revealed alterations in digestive gland cells, such as vacuolization and thickening. The lipid peroxidation showed a trend to increase for the different tested NDs concentrations which is compatible with the observed cellular damage.

Bioaccumulation of selenium and induced biological effects in the filter feeding bivalve Corbicula fluminea: influence of ventilatory activity, selenium speciation and route of transfer

International Nuclear Information System (INIS)

Fournier, E.

2005-10-01

Selenium is an essential micro-nutrient for most of living organisms. However, toxic effects in several ecosystems have been reported in the literature. Toxicity comprehension is difficult due to the complexity of Se oxidation states in the environment. The aim of this thesis work was to acquire knowledge on the physiological and environmental factors involved in bioaccumulation and toxicity processes in the freshwater filter-feeding bivalve C. fluminea. The aims were: i) to define what the factors involved in Se bioaccumulation processes in the bivalve are, ii) to characterize Se bioaccumulation at different biological organisation levels, iii) to investigate Se toxic effects. First experiments, carried out for short term exposure duration (3 days), have permitted to underline the importance of Se chemical speciation in bioaccumulation processes in C. fluminea. It has been shown that the organic form, seleno-methionine, was much more bio-available than the inorganic forms, selenite and selenate. Moreover, the route of transfer was determinant in those processes. Inorganic forms have been better extracted by trophic route, whereas seleno-methionine has been better extracted by the direct route. In our experimental conditions, ventilation of the bivalve has not been a limiting factor for Se bioaccumulation by the direct route, whereas it has been for bioaccumulation by the trophic route. Ventilation has been largely modified by the presence of dissolved selenite and seleno-methionine. We have shown that the kinetics of seleno-methionine bioaccumulation are much more fast than those of selenite. Moreover, when introduced as SeMet, internalized Se appeared to be relatively remanent in soft tissues of C. fluminea in comparison with Se internalized when introduced as selenite. Subcellular and molecular distributions of these forms were very different. Finally, it has been shown that seleno-methionine and selenite could generate weak alterations of the anti

Bioaccumulation of selenium and induced biological effects in the filter feeding bivalve Corbicula fluminea: influence of ventilatory activity, selenium speciation and route of transfer; Bioaccumulation du selenium et effets biologiques induits chez le bivalve filtreur Corbicula fluminea: prise en compte de l'activite ventilatoire, de la speciation du selenium et de la voie de contamination

Energy Technology Data Exchange (ETDEWEB)

Fournier, E

2005-10-15

Selenium is an essential micro-nutrient for most of living organisms. However, toxic effects in several ecosystems have been reported in the literature. Toxicity comprehension is difficult due to the complexity of Se oxidation states in the environment. The aim of this thesis work was to acquire knowledge on the physiological and environmental factors involved in bioaccumulation and toxicity processes in the freshwater filter-feeding bivalve C. fluminea. The aims were: i) to define what the factors involved in Se bioaccumulation processes in the bivalve are, ii) to characterize Se bioaccumulation at different biological organisation levels, iii) to investigate Se toxic effects. First experiments, carried out for short term exposure duration (3 days), have permitted to underline the importance of Se chemical speciation in bioaccumulation processes in C. fluminea. It has been shown that the organic form, seleno-methionine, was much more bio-available than the inorganic forms, selenite and selenate. Moreover, the route of transfer was determinant in those processes. Inorganic forms have been better extracted by trophic route, whereas seleno-methionine has been better extracted by the direct route. In our experimental conditions, ventilation of the bivalve has not been a limiting factor for Se bioaccumulation by the direct route, whereas it has been for bioaccumulation by the trophic route. Ventilation has been largely modified by the presence of dissolved selenite and seleno-methionine. We have shown that the kinetics of seleno-methionine bioaccumulation are much more fast than those of selenite. Moreover, when introduced as SeMet, internalized Se appeared to be relatively remanent in soft tissues of C. fluminea in comparison with Se internalized when introduced as selenite. Subcellular and molecular distributions of these forms were very different. Finally, it has been shown that seleno-methionine and selenite could generate weak alterations of the anti

Biofiltration using C. fluminea for E.coli removal from water: Comparison with ozonation and photocatalytic oxidation.

Science.gov (United States)

Gomes, João F; Lopes, Ana; Gonçalves, Daniel; Luxo, Cristina; Gmurek, Marta; Costa, Raquel; Quinta-Ferreira, Rosa M; Martins, Rui C; Matos, Ana

2018-06-06

Corbicula fluminea, an Asian clam, is one of the worst invasive species in Europe that can survive in very adverse environmental conditions. Despite its negative impacts, the species also has the capacity to bioaccumulate heavy metals, contaminants and can be exploited for wastewater treatment purposes. The capacity of the Asian clam to remove Escherichia coli, used as fecal contamination indicator, was analyzed. Conventional wastewater treatment plants are not suitable to remove bacteria, thus resulting in treated municipal wastewater with high bacterial loads. E. coli clearance rate was analyzed as function of the number of clams. The bivalves can remove bacteria until concentrations below the detection limit in about 6 h. The adsorption on the clam shells' and bioaccumulation on the soft tissues were also analyzed. The depuration of clams along 48 h were analyzed revealing that no bacteria was detected in the water. Thus, these results suggest that Asian clam can bioprocess E. coli. On the other hand, results obtained by this methodology were compared with ozonation and photocatalytic oxidation using TiO 2 , Ag, Au, Pd-TiO 2 . In all treatments it was possible to achieve concentrations of E. coli below the detection limit. However, photocatalytic oxidation demands about 4700 folds more energy than ozonation, besides the costs associated with catalysts. Comparing complexity of ozonation with biofiltration, this study suggests that application of biofiltration using C. fluminea can be a suitable solution to minimize the presence of bacteria in wastewater, reducing environmental and economic impacts. Copyright © 2018 Elsevier Ltd. All rights reserved.

Interactions of Corbicula sp. with power plants

International Nuclear Information System (INIS)

Mattice, J.S.

1977-01-01

There are three perspectives with which to view the interaction of Corbicula and power plants: as a fouling agent; as an important part of the natural ecosystem; and as a potential species for use in waste heat aquaculture. The first two of these interactions are essentially negative in character, since they involve avoidance of impacts either of Corbicula on power plant operation or of power plant operation on Corbicula. Condenser fouling by these claims has been controlled by mechanical means or by continuous chlorination. Our data support the potential for using heated water to control fouling and a model for determining required thermal dosing is presented. Preliminary data also indicate potential for control by combining simultaneous short-term exposure to hot water and chlorine. The third of the interactions is essentially positive in character. The use of thermal effluents in Corbicula aquaculture systems is proposed

Engineering factors influencing Corbicula fouling in nuclear-service water systems

International Nuclear Information System (INIS)

Henager, C.H.; Johnson, K.I.; Page, T.L.

1983-06-01

Corbicula fouling is a continuing problem in nuclear-service water systems. More knowledge of biological and engineering factors is needed to develop effective detection and control methods. A data base on Corbicula fouling was compiled from nuclear and non-nuclear power stations and industries using raw water. This data base was used in an analysis to identify systems and components which are conducive to fouling by Corbicula. Bounds on several engineering parameters such as velocity and temperature which support Corbicula growth are given. Service water systems found in BWR and PWR reactors are listed and those that show fouling are identified. Possible safety implications of Corbicula fouling are discussed for specific service water systems. Several effective control methods in current use include backflushing with heated water, centrifugal strainers, and continuous chlorination during spawning seasons

Biofouling of power-plant service systems by Corbicula

International Nuclear Information System (INIS)

Page, T.L.; Neitzel, D.A.; Simmons, M.A.; Hayes, P.F.

1983-08-01

Corbicula sp. foul the service water systems at nuclear power plants because the environment within these systems is compatible with the ecological requirements of the species. To reduce Corbicula fouling, components of service water systems and operating procedures that enhance the potential for fouling need to be identified. Factors important in mediating biofouling of service water systems appear to be screening potential, minimum and maximum velocities and the operational procedures employed during power plant biofoulant control and downtime. These conclusions are based on the results of a categorical model we used to correlate information from power plants with that on Corbicula life history. Power plant parameters in the model include temperature, dissolved oxygen concentration, screen and strainer size, maximum and minimum velocities, and elements of the biofouling control procedures. Parameters for Corbicula include tolerances to temperature, dissolved oxygen, biofouling control chemicals, velocity preferences, and optimal temperatures for each life stage and behavior. 13 references, 5 figures

Progressing Insensitive Munitions: Benefits and Techniques for Proactively Addressing Environmental Regulations

Science.gov (United States)

2012-05-01

X Worm Tubifex tubifex X X X Black worm Lumbriculus X Asiatic clam Corbicula fluminea X Estuarine/marine water column Mysid shrimp Americamysis...Objective: Characterize traditional and insensitive munitions (IMs) impacts on amphibian larvae to manage a candidate for T&E status that inhabit

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

International Nuclear Information System (INIS)

Simon, Olivier; Garnier-Laplace, Jacqueline

2005-01-01

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

Patrones de colonización y ecología de poblaciones de dos bivalvos invasores (mejillón cebra Dreissena polymorpha Pallas, 1771 y almeja asiática Corbicula fluminea Müller, 1774 en un tramo lótico del Ebro medio (Castejón, Navarra.

Directory of Open Access Journals (Sweden)

MORALES, J., FLECHOSO, F., LIZANA, M., NEGRO, A.

2013-01-01

Full Text Available Los bivalvos dulceacuícolas son un componente importante de la ecología fluvial, fundamentalmente por el papel que desempeñan como organismos filtradores y de remoción del sedimento. Además son un grupo zoológico diverso y amenazado a escala global, en el que se incluyen algunas de las especies invasoras más dañinas. El estudio de sus poblaciones es imprescindible para conocer el estado de conservación de las comunidades bentónicas. Para esto se prospectaron 17 parcelas vadeables y 7 escolleras a lo largo de 7,38 km de meandros del río Ebro en Castejón (Navarra, tanto el cauce principal como en brazos secundarios de corriente permanente y/o temporal. El mejillón cebra Dreissena polymorpha Pallas, 1771 se encontró en 7 escolleras y 6 parcelas. El sustrato preferente fueron rocas (85%, donde la densidad resultó 0,31-5,45 mejillones/m2; el 2,6% se hallaron sobre plásticos agrícolas abandonados. En las escolleras sólo el 3,6% de los ejemplares eran juveniles y un 33% tenían una edad > 4 años. La almeja asiática Corbicula fluminea Müller, 1774 se encontró en todas las parcelas. La densidad resultó muy diferente en los tres tipos de ambientes fluviales con valores máximos de 15.100 almejas/m2, lo que constituye un nuevo máximo fluvial en Europa. Se encontraron subpoblaciones de almeja asiática con diferentes estructuras de edad según los ambientes fluviales, además de poblaciones menos numerosas en el brazo principal del río que en los otros tipos. Los resultados muestran que junto a estas especies alóctonas en expansión, con altas tasas de reclutamiento, se encuentra una estructura poblacional muy precaria para las autóctonas, de las cuales únicamente se localizaron 12 náyades vivas y ningún esférido.

Community structure and decadal changes in macrozoobenthic assemblages in Lake Poyang, the largest freshwater lake in China

Directory of Open Access Journals (Sweden)

Cai Y. J.

2014-01-01

Full Text Available Lake Poyang is the largest freshwater lake in China and contains unique and diverse biota within the Yangtze floodplain ecosystem. However, knowledge of its macrozoobenthic assemblages remains inadequate. To characterize the current community structure of these assemblages and to portray their decadal changes, quarterly investigations were conducted at 15 sites from February to November 2012. A total of 42 taxa were recorded, and Corbicula fluminea, Limnoperna fortunei, Gammaridae sp., Nephtys polybranchia, Polypedilum scalaenum and Branchiura sowerbyi were found to dominate the community in terms of abundance. The bivalves Corbicula fluminea, Lamprotula rochechouarti, Arconaia lanceolata and Lamprotula caveata dominated the community in biomass due to their large body size. The mean abundance of the total macrozoobenthos varied from 48 to 920 ind·m-2, the mean biomass ranged from 28 to 428 g·m-2. The substrate type affected strongly the abundance, biomass, and diversity of the macrozoobenthos, with muddy sand substrates showing the highest values. Compared with historical data, remarkable changes were observed in the abundance of macrozoobenthos and the identity of the dominant species. The mean total abundance decreased from 724 ind·m-2 in 1992 to 228 ind·m-2 in 2012. The dominant species have shifted dramatically. Large unionids were dominant before 1998, whereas pollution-tolerant species (e.g., Branchiura sowerbyi increased in dominance after 2008. Our findings should have implications for the conservation of the benthic biodiversity of this large Yangtze-connected lake.

Zoochorous dispersal of freshwater bivalves: an overlooked vector in biological invasions?

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Coughlan Neil E.

2017-01-01

Full Text Available Vectors that underpin the natural dispersal of invasive alien species are frequently unknown. In particular, the passive dispersal (zoochory of one organism (or propagule by another, usually more mobile animal, remains poorly understood. Field observations of the adherence of invasive freshwater bivalves to other organisms have prompted us to assess the importance of zoochory in the spread of three prolific invaders: zebra mussel Dreissena polymorpha; quagga mussel Dreissena bugensis; and Asian clam Corbicula fluminea. An extensive, systematic search of the literature was conducted across multiple on-line scientific databases using various search terms and associated synonyms. In total, only five publications fully satisfied the search criteria. It appears that some fish species can internally transport viable adult D. polymorpha and C. fluminea specimens. Additionally, literature indicates that veligers and juvenile D. polymorpha can adhere to the external surfaces of waterbirds. Overall, literature suggests that zoochorous dispersal of invasive bivalves is possible, but likely a rare occurrence. However, even the establishment of a few individuals (or a single self-fertilising C. fluminea specimen can, over-time, result in a substantial population. Here, we highlight knowledge gaps, identify realistic opportunities for data collection, and suggest management protocols to mitigate the spread of invasive alien species.

The influence of fish cage culture on δ{sup 13}C and δ{sup 15}N of filter-feeding Bivalvia (Mollusca)

Energy Technology Data Exchange (ETDEWEB)

Benedito, E.; Takeda, A.M., E-mail: eva@nupelia.uem.br [Universidade Estadual de Maringa (UEM), PR (Brazil). Nucleo de Pesquisas em Limnologia, Ictiologia e Aquicultura; Figueroa, L. [Universidade Estadual de Maringa (UEM), PR (Brazil). Pos-Graduacao em Ecologia de Ambientes Aquaticos Continentais; Manetta, GI. [Universidade Estadual de Maringa (UEM), PR (Brazil). Pos-Graduacao em Biologia Comparada

2013-11-15

The objective of this study was to evaluate the effect of Oreochromis niloticus cage culture promoted variations in the δ{sup 13}C and δ{sup 15}N in Corbicula fluminea (Mollusca; Bivalvia) and in the sediment of an aquatic food web. Samples were taken before and after net cage installation in the Rosana Reservoir (Paranapanema River, PR-SP). Samples of specimens of the bivalve filter C. fluminea and samples of sediment were collected using a modified Petersen grab. All samples were dried in an oven (60 °C) for 72 hours, macerated to obtain homogenous fine powders and sent for carbon (δ{sup 13}C) and nitrogen (δ{sup 15}N) isotopic value analysis in a mass spectrometer. There were significant differences in the δ{sup 13}C and δ{sup 15}N values of the invertebrate C. fluminea between the beginning and the end of the experiment. There were no differences between the δ{sup 13}C and δ{sup 15}N values of sediment. These results indicate that the installation of fish cage culture promoted impacts in the isotopic composition of the aquatic food web organisms, which could exert influence over the native species and the ecosystem. (author)

An annotated list of the species of the genus Corbicula from Indonesia (Mollusca: Corbiculidae)

NARCIS (Netherlands)

Djajasasmita, Machfudz

1977-01-01

The species of the genus Corbicula known from Indonesia are alphabetically listed and noted. Sixteen out of the 35 described species are considered valid, i.e. C. gustaviana, C. moltkiana, C. sumatrana, C. tobae and C. tumida from Sumatra; C. javanica, C. pulchella and C. rivalis from Java; C.

Fauna Europaea: Mollusca – Bivalvia

Directory of Open Access Journals (Sweden)

Rafael Araujo

2015-07-01

European freshwater bivalves belong to the Orders Unionoida and Cardiida. All the European unionoids are included in the superfamily Unionoidea, the freshwater mussels or naiads. The European cardiids belong to the following three superfamilies: Cardioidea, Cyrenoidea and Dreissenoidea. Among the Unionoidea there are the most imperilled animal groups on the planet while the Cardioidea includes the cosmopolitan genus Pisidium, the Cyrenoidea the Asiatic clam (Corbicula fluminea and the Dreissenoidea the famous invasive zebra mussel (Dreissena polymorpha. Basic information is summarized on their taxonomy and biology. Tabulations include a complete list of the current estimated families, genera and species.

From water to land: How an invasive clam may function as a resource pulse to terrestrial invertebrates.

Science.gov (United States)

Novais, Adriana; Souza, Allan T; Ilarri, Martina; Pascoal, Cláudia; Sousa, Ronaldo

2015-12-15

Resource pulses are episodes of low frequency, large magnitude and short duration that result in increased resource availability in space and time, with consequences for food web dynamics. Studies assessing the importance of resource pulses by invasive alien species in the interface between terrestrial and aquatic ecosystems are rare, especially those in the direction from water to land. This study assessed the importance of massive die-offs of the Asian clam Corbicula fluminea (Müller, 1774) as a resource pulse to the terrestrial invertebrate community after an extreme climatic event using a manipulative experiment. We used 5 levels of C. fluminea density (0, 100, 500, 1000 and 2000ind·m(-2)), with terrestrial invertebrates being censused 7, 30 and 90days after C. fluminea addition. We also assessed the possible effect of plots position, where plots that delimited the experiment were assigned as edge plots and the remaining as core plots. Clear differences were detected in abundance, biomass, richness and diversity of terrestrial invertebrates depending on the C. fluminea density, time and position. Interestingly, the highest abundance of adult Diptera was observed 7days after C. fluminea addition, whereas that of the other terrestrial invertebrates was on day 30, both with C. fluminea densities higher than 500ind·m(-2) located on the edge of the experimental design. This study highlights the importance of major resource pulses after massive die-offs of invasive bivalves, contributing with remarkable amounts of carrion for adjacent terrestrial systems. Part of this carrion can be consumed directly by a great number of invertebrate species while the remainder can enter the detrital food web. Given the high density and biomass attained by several invasive bivalves worldwide and the predicted increase in the number, intensity and magnitude of extreme climatic events, the ecological importance of this phenomenon should be further investigated. Copyright © 2015

Using biochemical and isotope geochemistry to understand the environmental and public health implications of lead pollution in the lower Guadiana River, Iberia: A freshwater bivalve study

Energy Technology Data Exchange (ETDEWEB)

Company, R. [CIMA, Faculty of Marine and Environmental Sciences, University of Algarve, Campus de Gambelas, 8005-139 Faro (Portugal)], E-mail: rcompany@ualg.pt; Serafim, A.; Lopes, B.; Cravo, A. [CIMA, Faculty of Marine and Environmental Sciences, University of Algarve, Campus de Gambelas, 8005-139 Faro (Portugal); Shepherd, T.J.; Pearson, G. [Department of Earth Sciences, Durham University, Science Labs., Durham DH1 3LE (United Kingdom); Bebianno, M.J. [CIMA, Faculty of Marine and Environmental Sciences, University of Algarve, Campus de Gambelas, 8005-139 Faro (Portugal)], E-mail: mbebian@ualg.pt

2008-11-01

Lead is a natural component of aquatic ecosystems with no known biological role and is highly toxic. Its toxicity stems from its ability to mimic biologically important metals and to produce membrane damage through lipid peroxidation (LPO). Most lead poisoning symptoms are thought to occur by interfering with an essential enzyme, {delta}-aminolevulinic acid dehydratase (ALAD), the activity of which is markedly inhibited by lead. The purpose of this work was to study the levels and effects of lead pollution (responses of ALAD and oxidative stress biomarker LPO) in the freshwater bivalve Corbicula fluminea along the lower Guadiana River (Portugal and Spain); a major river system impacted by historic mining pollution and more recent anthropogenic inputs. The results show that the enzymatic activity of ALAD is negatively correlated with the total Pb concentration of the whole tissue suggesting that ALAD has considerable potential as a biomarker of lead exposure in C. fluminea. To identify the sources of lead to which bivalves have been exposed, high precision {sup 206}Pb/{sup 204}Pb, {sup 207}Pb/{sup 204}Pb, {sup 208}Pb/{sup 204}/Pb ratios for C. fluminea confirm that historical mining activities in the Iberian Pyrite Belt are the dominant source of lead pollution in the lower Guadiana River. The isotope patterns however exhibit marked seasonal and geographic variation in response to rainfall and river water management. Locally, other anthropogenic sources of lead have been detected in C. fluminea close to population centres, thus adding to its versatility as a freshwater bio-indicator. Overall, the study highlights the value of natural ecosystems as monitors of water quality and their importance for public health assessment and surveillance.

Using biochemical and isotope geochemistry to understand the environmental and public health implications of lead pollution in the lower Guadiana River, Iberia: a freshwater bivalve study.

Science.gov (United States)

Company, R; Serafim, A; Lopes, B; Cravo, A; Shepherd, T J; Pearson, G; Bebianno, M J

2008-11-01

Lead is a natural component of aquatic ecosystems with no known biological role and is highly toxic. Its toxicity stems from its ability to mimic biologically important metals and to produce membrane damage through lipid peroxidation (LPO). Most lead poisoning symptoms are thought to occur by interfering with an essential enzyme, delta-aminolevulinic acid dehydratase (ALAD), the activity of which is markedly inhibited by lead. The purpose of this work was to study the levels and effects of lead pollution (responses of ALAD and oxidative stress biomarker LPO) in the freshwater bivalve Corbicula fluminea along the lower Guadiana River (Portugal and Spain); a major river system impacted by historic mining pollution and more recent anthropogenic inputs. The results show that the enzymatic activity of ALAD is negatively correlated with the total Pb concentration of the whole tissue suggesting that ALAD has considerable potential as a biomarker of lead exposure in C. fluminea. To identify the sources of lead to which bivalves have been exposed, high precision (206)Pb/(204)Pb, (207)Pb/(204)Pb, (208)Pb/(204)/Pb ratios for C. fluminea confirm that historical mining activities in the Iberian Pyrite Belt are the dominant source of lead pollution in the lower Guadiana River. The isotope patterns however exhibit marked seasonal and geographic variation in response to rainfall and river water management. Locally, other anthropogenic sources of lead have been detected in C. fluminea close to population centres, thus adding to its versatility as a freshwater bio-indicator. Overall, the study highlights the value of natural ecosystems as monitors of water quality and their importance for public health assessment and surveillance.

Using biochemical and isotope geochemistry to understand the environmental and public health implications of lead pollution in the lower Guadiana River, Iberia: A freshwater bivalve study

International Nuclear Information System (INIS)

Company, R.; Serafim, A.; Lopes, B.; Cravo, A.; Shepherd, T.J.; Pearson, G.; Bebianno, M.J.

2008-01-01

Lead is a natural component of aquatic ecosystems with no known biological role and is highly toxic. Its toxicity stems from its ability to mimic biologically important metals and to produce membrane damage through lipid peroxidation (LPO). Most lead poisoning symptoms are thought to occur by interfering with an essential enzyme, δ-aminolevulinic acid dehydratase (ALAD), the activity of which is markedly inhibited by lead. The purpose of this work was to study the levels and effects of lead pollution (responses of ALAD and oxidative stress biomarker LPO) in the freshwater bivalve Corbicula fluminea along the lower Guadiana River (Portugal and Spain); a major river system impacted by historic mining pollution and more recent anthropogenic inputs. The results show that the enzymatic activity of ALAD is negatively correlated with the total Pb concentration of the whole tissue suggesting that ALAD has considerable potential as a biomarker of lead exposure in C. fluminea. To identify the sources of lead to which bivalves have been exposed, high precision 206 Pb/ 204 Pb, 207 Pb/ 204 Pb, 208 Pb/ 204 /Pb ratios for C. fluminea confirm that historical mining activities in the Iberian Pyrite Belt are the dominant source of lead pollution in the lower Guadiana River. The isotope patterns however exhibit marked seasonal and geographic variation in response to rainfall and river water management. Locally, other anthropogenic sources of lead have been detected in C. fluminea close to population centres, thus adding to its versatility as a freshwater bio-indicator. Overall, the study highlights the value of natural ecosystems as monitors of water quality and their importance for public health assessment and surveillance

Annual harvests of Corbicula populations prevent clogging of nuclear reactor heat exchangers

International Nuclear Information System (INIS)

Harvey, R.S.

1983-01-01

An annual program for removal of millions of Corbicula from upstream cooling water basins has prevented reclogging of nuclear reactor heat exchanger distributor plates at the Savannah River Plant during the past seven years. There are nine 32-megaliter basins in the three operating reactor areas where some settling of particulates occurs before cooling water is passed through screens in route to heat exchangers. Annual cleanings keep silt/clam substrate levels low and clam sizes small. Data are presented on the size/age distribution for clams recolonizing basins between cleanings

Non-indigenous invertebrates, fish and macrophytes in Lake Garda (Italy

Directory of Open Access Journals (Sweden)

Cristina CAPPELLETTI

2011-08-01

Full Text Available As observed in many countries, lakes are involved in an important process of colonization by non-indigenous species (NIS. Since 1725, 37 species of non-indigenous fish, invertebrates and macrophytes have been recorded in Lake Garda, the largest Italian lake. This phenomenon is particularly important for invertebrates and macrophytes, as their pathways of introduction are accidental. Recently among the 100 Worst Invasive Alien Species in Europe, the invertebrates Corbicula fluminea, Dikerogammarus villosus and Procambarus clarkii, and the macrophytes Lagarosiphon major, Elodea nuttallii and Elodea canadensis have been recorded in Lake Garda. In order to define the present status of non-indigenous species in Lake Garda, published and unpublished data were reviewed.

L’INVASION DU RÉSEAU HYDROGRAPHIQUE FRANÇAIS PAR LES MOLLUSQUES CORBICULA SPP. MODALITÉ DE COLONISATION ET RÔLE PRÉPONDÉRANT DES CANAUX DE NAVIGATION.

Directory of Open Access Journals (Sweden)

BRANCOTTE V.

2002-04-01

Full Text Available Originaire d’Asie et d’Afrique, Corbicula a colonisé la plupart des bassins hydrographiques européens depuis 1980. A la faveur de la découverte de nouvelles stations, les auteurs mettent en évidence l’importance du rôle des canaux de navigation dans la propagation du mollusque, par la mise en connexion des bassins versants et l’existence d’un milieu particulièrement favorable à la biologie de l’espèce. Corbicula a pénétré en France par au moins sept axes différents, parmi lesquels le Rhin joue un rôle prépondérant.

Structure and spatial patterns of macrobenthic community in Tai Lake, a large shallow lake, China

Science.gov (United States)

Di Li,; Erickson, Richard A.; Song Tang,; Xuwen Li,; Niu, Zhichun; Xia Wang,; Hongling Liu,; Hongxia Yu,

2016-01-01

Tai Lake (Chinese: Taihu), the third-largest freshwater lake in China, suffers from harmful cyanobacteria blooms that are caused by economic development and population growth near the lake. Several studies have focused on phytoplankton in Tai Lake after a drinking water crisis in 2007; however, these studies primarily focused on microcystin bioaccumulation and toxicity to individual species without examining the effects of microcystin on macrobenthic community diversity. In this study, we conducted a survey of the lake to examine the effects of microcystine and other pollutants on marcobenthic community diversity. A totally of forty-nine species of macroinvertebrates were found in Tai Lake. Limnodrilus hoffmeisteri and Corbicula fluminea were the most abundant species. Cluster-analysis and one-way analysis of similarity (ANOSIM) identified three significantly different macrobenthic communities among the sample sites. More specifically, sites in the eastern bays, where aquatic macrophytes were abundant, had the highest diversity of macrobenthic communities, which were dominated by Bellamya aeruginosa, Bellamya purificata, L. hoffmeisteri, and Alocinma longicornis. Sites in Zhushan Bay contained relatively diverse communities, mainly composed of L. hoffmeisteri, C. fluminea, L. claparederanus, R. sinicus, and Cythura sp. Sites in the western region, Meiliang Bay and Wuli Bay had the lowest diversity, mainly composed ofL. hoffmeisteri, C. fluminea, Branchiura sowerbyi, and Rhyacodrilus sinicus. In addition, the relationships between macrobenthic metrics (Shannon–Wiener, Margalef, and Pielou) and environmental variables showed that community structure and spatial patterns of macrobenthos in Tai Lake were significantly influenced by chemical oxygen demand (CODCr), biochemical oxygen demand (BOD5), lead (Pb), and microcystin-LR (L for leucine and R for arginine). Our findings provide critical information that could help managers and policymakers

Assessing arsenic bioavailability through the use of bioassays

Science.gov (United States)

Diesel, E.; Nadimpalli, M.; Hull, M.; Schreiber, M. E.; Vikesland, P.

2009-12-01

Various methods have been used to characterize the bioavailability of a contaminant, including chemical extractions from soils, toxicity tests, bioaccumulation measurements, estimation from soil properties, in vitro/in vivo tests, and microbial biossays. Unfortunately, these tests are all unique (i.e. they measure bioavailability through different mechanisms) and it is difficult to compare measurements collected using one method to those collected from another. Additionally, there are fundamental aspects of bioavailability research that require further study. In particular, changes in bioavailability over time are not well understood, as well as what the geochemical controls are on changes in bioavailability. In addition, there are no studies aimed at the integration of bioavailability measurements and potential geochemical controls. This research project seeks to find a standard set of assays and sensors that can be used to assess arsenic bioavailability at any field site, as well as to use these tools and techniques to better understand changes in, and controls on, arsenic bioavailability. The bioassays to be utilized in this research are a bioluminescent E. coli assay and a Corbicula fluminea (Asian clam) assay. Preliminary experiments to determine the suitability of the E. coli and C. fluminea assays have been completed. The E. coli assay can be utilized to analyze As(III) and As(V) with a linear standard curve between 5 and 200 ppb for As(III) and 100 ppb and 5 ppm for As(V); no bioluminescent response above background was elicited in the presence of Roxarsone, an organoarsenical. The C. fluminea assay is capable of bioaccumulating As(III), As(V), Roxarsone, and MSMA, with As(III) being the most readily accumulated, followed by As(V), Roxarsone and MSMA, respectively. Additional research will include assessing bioavailability of various arsenic species adsorbed to natural colloidal materials (i.e. clays, iron oxides, NOM) to the E. coli and C. fluminea assays

Evaluation of Using Caged Clams to Monitor Contaminated Groundwater Exposure in the Near-Shore Environment of the Hanford Site 300 Area

Energy Technology Data Exchange (ETDEWEB)

Larson, Kyle B.; Poston, Ted M.; Tiller, Brett L.

2008-01-31

The Asiatic clam (Corbicula fluminea) has been identified as an indicator species for locating and monitoring contaminated groundwater in the Columbia River. Pacific Northwest National Laboratory conducted a field study to explore the use of caged Asiatic clams to monitor contaminated groundwater upwelling in the 300 Area near-shore environment and assess seasonal differences in uranium uptake in relation to seasonal flow regimes of the Columbia River. Additional objectives included examining the potential effects of uranium accumulation on growth, survival, and tissue condition of the clams. This report documents the field conditions and procedures, laboratory procedures, and statistical analyses used in collecting samples and processing the data. Detailed results are presented and illustrated, followed by a discussion comparing uranium concentrations in Asiatic clams collected at the 300 Area and describing the relationship between river discharge, groundwater indicators, and uranium in clams. Growth and survival, histology, and other sources of environmental variation also are discussed.

Integrative assessment of sediment quality in lower basin affected by former mining in Brazil.

Science.gov (United States)

Bonnail, Estefanía; Buruaem, Lucas M; Morais, Lucas G; Araujo, Giuliana S; Abessa, Denis M S; Sarmiento, Aguasanta M; Ángel DelValls, T

2017-06-13

The Ribeira de Iguape River (Southeast Brazil) is metal contaminated by mining activities. Despite it has been cataloged as "in via of restoration" by the literature, this basin is still a sink of pollution in some segments of the fluvial system. This study aimed to assess the sediment quality in the lower part of the RIR basin. The employed approach was based on biological responses of the freshwater clam Corbicula fluminea after 7-day exposure bioassays using as the reference site the Perequê Ecological Park. Toxic responses (burial activity and lethality) and biochemical biomarkers (GST, GR, GPx, LPO, MTs, AChE and DNA damage) were evaluated and then integrated with metal bioavailability and chemical concentrations to address the sediment quality in the area through the weight-of-evidence approach. A multivariate analysis identified linkages between biological responses and contamination. Results pointed that, despite being below the benchmarks of the US Environmental Protection Agency, there is slight metal contamination in the lower part of the basin which induces oxidative stress in C. fluminea; other toxic responses were sometimes attributed to As and Cr bioaccumulation. The sediment quality values (TEL-PEL values in mg/kg) were calculated for the current study for As (0.63-1.31), Cr (3.5-11.05), Cs (1.0-1.17), Cu (6.32-7.32), Ni (6.78-7.46), Ti (42.0-215), V (1.77-8.00). By comparison with other international guidelines, the sediment quality of the lower basin of the Vale de Ribeira does not identify a significant environmental risk.

Ecological consequences of invasion across the freshwater-marine transition in a warming world.

Science.gov (United States)

Crespo, Daniel; Solan, Martin; Leston, Sara; Pardal, Miguel A; Dolbeth, Marina

2018-02-01

The freshwater-marine transition that characterizes an estuarine system can provide multiple entry options for invading species, yet the relative importance of this gradient in determining the functional contribution of invading species has received little attention. The ecological consequences of species invasion are routinely evaluated within a freshwater versus marine context, even though many invasive species can inhabit a wide range of salinities. We investigate the functional consequences of different sizes of Corbicula fluminea -an invasive species able to adapt to a wide range of temperatures and salinity-across the freshwater-marine transition in the presence versus absence of warming. Specifically, we characterize how C. fluminea affect fluid and particle transport, important processes in mediating nutrient cycling (NH 4 -N, NO 3 -N, PO 4 -P). Results showed that sediment particle reworking (bioturbation) tends to be influenced by size and to a lesser extent, temperature and salinity; nutrient concentrations are influenced by different interactions between all variables (salinity, temperature, and size class). Our findings demonstrate the highly context-dependent nature of the ecosystem consequences of invasion and highlight the potential for species to simultaneously occupy multiple components of an ecosystem. Recognizing of this aspect of invasibility is fundamental to management and conservation efforts, particularly as freshwater and marine systems tend to be compartmentalized rather than be treated as a contiguous unit. We conclude that more comprehensive appreciation of the distribution of invasive species across adjacent habitats and different seasons is urgently needed to allow the true extent of biological introductions, and their ecological consequences, to be fully realized.

A malacological survey in the Manso Power Plant, State of Mato Grosso, Brazil: new records of freshwater snails, including transmitters of schistosomiasis and exotic species

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Monica Ammon Fernandez

2014-07-01

Full Text Available Introduction Schistosomiasis is a parasitic disease of public health concern in Brazil, and the construction of hydroelectric dams, in addition to increasing permanent human settlement and tourism, has created conditions suitable for the establishment of mollusks that can transmit schistosomiasis. Such areas require a number of actions to prevent the establishment of schistosomiasis. This paper reports on a freshwater malacological survey carried out in the geographical area of the Manso Power Plant. Methods Mollusks were collected in 18 municipalities in the State of Mato Grosso between February 2002 and February 2004 (qualitative study and from April 2009 to February 2011 (quantitative study. Results Thirty-one species of mollusks were collected, including newly recorded species (Antillorbis nordestensis and Burnupia ingae. In addition, the geographic distributions of known species, including Biomphalaria straminea, a snail vector of Schistosoma mansoni, were expanded. A total of 4,507 specimens were collected in the APM Manso reservoir (Usina Hidrelétrica de Aproveitamento Múltiplo de Manso during the quantitative study, and Biomphalaria amazonica was found in six of the 10 localities analyzed. The Afroasiatic species Melanoides tuberculata, introduced after February 2009, was the dominant species (relative abundance 94.96%. Conclusions The study area is epidemiologically important due to the occurrence of B. straminea and B. amazonica, which are vectors of schistosomiasis, and M. tuberculata, a snail host of Centrocestus formosanus, which is responsible for centrocestiasis transmission. Observations of M. tuberculata and the exotic freshwater clams Corbicula fluminea and Corbicula largillierti raise concerns about biodiversity.

Corbicula fluminea as a Bioaccumulation Indicator Species: A Case Study at the Columbia and Willamette Rivers

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2009-06-01

Johnson and Norton 2005). Other studies ( Buske 2005; Kaltofen and Carpenter 2005) looked at radionuclide levels in clams along the 50-mile Hanford...resources from the Columbia River. Final Report. Portland, OR: US Fish and Wildlife Service, Oregon Fish and Wildlife Office. Buske , N. 2005

BEHAVIORAL AND PHYSIOLOGICAL RESPONSES OF DAPHNIA MAGNA, CHLORELLA VULGARIS, CORBICULA FLUMINEA, LEPOMIS MACROCHIRUS, AND VIBRO FISCHERI

Science.gov (United States)

The research presented here is a continuation of work designed to further the science of available and developing continuous, automated water quality monitors and how they may be most effectively deployed in a watershed management plan and/or water quality early warning system (W...

New method for control of biological fouling in pipelines based on elevated partial pressures of carbon dioxide or combustion exhaust gases.

Energy Technology Data Exchange (ETDEWEB)

B.J. Watten; R.E. Sears; R.F. Bumgardner [U.S. Geological Survey - Leetown Science Center, Kearneysville, WV (United States)

2005-07-01

Zebra mussels (Dreissena polymorpha) and Asian clams (Corbicula fluminea) are major macro fouling species of water conduits used in industrial and power station raw water/condensor systems. Control typically involves manual scraping and use of thermal treatment, deoxygenation or biocides. The costs of control and system damage resulting from fouling in the United States alone have been estimated at $1 billion/year. There is a pressing need for new economical and safe control strategies. Aquatic species in general are intolerant to increases in PCO{sub 2} given its effect on water, blood and hemolymph pH. These species are also sensitive to increases in elevated total dissolved gas pressure. The gas bubble disease that develops following exposure can, as with CO{sub 2} exposure, lead to mortality. We are exploiting this sensitivity by developing a control method based on manipulation of PCO{sub 2} or power plant exhaust gas (CO{sub 2}, 14%; SO{sub 2}, 0.3%), i.e., the supersaturation of hemolymph and tissues with gas followed by an induced (short term) pressure release designed to induce formation of gas emboli. SO{sub 2} present in stack gas acts with CO{sub 2} to reduce water and hemolymph pH so as to reduce required exposure periods. System effluents are degassed, CO{sub 2} recovered and pH adjusted if needed with alkaline reagents. Test results indicate the new process is effective at controlling C. fluminea as well as other target species, including crustaceans and fish. Required exposure periods (LT50) are short and decrease with increasing gas supersaturation levels. Gas recovery and reuse methods developed have reduced gas requirements by 85% making the method attractive economically and environmentally. 40 refs., 8 figs., 1 tab.

First records of Freshwater Bivalves of Ilha Grande National Park, Paraná, Brazil

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Flávio Henrique Ragonha

2014-03-01

Full Text Available The Ilha Grande National Park, Paraná, Brazil, is located in the Upper Paraná River and has characteristics typical of a floodplains. This protected area includes lagoons connected and disconnected to the Paraná River, although the latter also connect during periods of high water level, thus composing a heterogeneous group of lacustrine environments. The enormous potential the flora and fauna diversities are still little known to the region, as can be seen through benthic invertebrates, inclunding bivalves mollusks. The granulometric composition of these floodplain lagoons was formed mainly by mud and very fine sand. Furthermore, organic matter composition was predominantly of fine particulate. The other abiotic factors differed from lagoons located within the island of the park to those located in the left margin of Paraná River. The results demonstrated the importance of abiotic factors such as the physical composition of granulometric texture, organic matter and macrophyte banks, to the establishment of bivalves in these floodplain lagoons. We recorded bivalves of Pisidium (native, Diplodon (native, and Corbicula (invasive. The highest values of Diplodon sp. density were observed at São João/C lake, for Pisidium sterkianum (Pilsbry, 1897 at São João/M lake, and to Jatobá/C lagoon with high density of invasive species Corbicula fluminea (Müller, 1774. This study to obtain conduct the first records of freshwater bivalves in floodplains lagoon in the Ilha Grande National Park, and provides contributions to better understanding the ecology of these mollusks. The recording of native species in the region of Upper Paraná River floodplain after a lomg period without new records, demonstrated the importance of protecting the lagoons of the Ilha Grande National Park as they can be a possible refuge to some species of native freshwater bivalves.

Macrofouling control in nuclear power plants

International Nuclear Information System (INIS)

Ekis, E.W. Jr.; Keoplin-Gall, S.M.; McCarthy, R.E.

1991-01-01

Macrofouling of cooling-water systems is one of the more significant and costly problems encountered in the nuclear power industry. Both marine and freshwater macroinvertebrates can be responsible for losses in plant availability because of plugged intakes and heat transfer equipment. There is a greater diversity of macrofouling organisms in marine waters than in fresh waters. Marine macrofouling organisms include barnacles, mollusks, bryozoans, and hydroids. Barnacles are crustaceans with feathery appendages, which allow them to attach to a variety of surfaces. They are a major cause of severe macrofouling because they can remain attached even after death. The major freshwater macrofouling organisms include the Asiatic Clam (Corbicula fluminea) and the newest freshwater macrofouler, the Zebra Mussel (Dreissena polymorpha). The introduction of the Zebra Mussel into the Great Lakes has created economic and ecological problems that will not easily be solved. The threat of intercontinental dispersal of the Zebra Mussel in America is serious. Research programs have been initiated around the country to develop control methods for this macrofouling problem. The various control methodologies can be classified in the following categories: biological, chemical, physical, and mechanical. Laboratory experiments were performed to evaluate the efficacy of Actibrom against mature Zebra Mussels

Characterization of freshwater bivalves as radio contamination (57Co, 110mAg, 134Cs) bio-indicators in a metallic multi pollution context (Cd, Zn)

International Nuclear Information System (INIS)

Fraysse, B.

2001-07-01

This study concerns freshwater bio-indicators of radio-contamination, in a metallic multi-pollution context. Metals, such as cadmium (Cd) and zinc (Zn), are widely represented in aquatic ecosystems, and their concentrations can induce physiological effects. This chronicle exposure generates both metabolic and behaviour stress of individuals, and can also yield to detoxification mechanisms induction. The main goal of this work was to estimate the influence of metals on the radionuclides ( 57 Co, 110m Ag, 134 Cs) bioaccumulation by two different bivalve species (Corbicula fluminea et Dreissena polymorpha), by studying the contamination level, the kinetic of the radionuclide transfer and the soft-body repartition. As the exploratory feature of this study, two parts have been developed: (i) testing the problematic suitability in a really bio-monitoring situation, and (ii) analysing the metal/radionuclide interaction mechanisms under controlled and standardised conditions (laboratory). For the different experimental conditions explored (laboratory and field), radionuclide bioaccumulation by freshwater bivalves has been influenced by metal exposure. This result was obtained after assessing a decrease of the organisms contamination level by radionuclide and their accumulation rate, an increase of their depuration rate and tissue and cellular repartition changes. (author)

BEHAVIORAL AND PHYSIOLOGICAL RESPONSES OF DAPHNIA MAGNA, CHLORELLA VULGARIS, CORBICULA FLUMINEA, AND LEPOMIS MACROCHIRUS TO COPPER AND CYANIDE

Science.gov (United States)

The research presented here was designed to further the science of available and developing continuous, automated water quality monitors and how they may be most effectively deployed in a watershed management plan and/or water quality early warning system (WQEWS). Source waters ...

Malacología Latinoamericana: Moluscos de agua dulce de Argentina

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Alejandra Rumi

2008-03-01

Full Text Available Se presenta un estado de situación y una lista actualizada y comentada sobre las especies de moluscos de agua dulce de la República Argentina. Se aborda en Gastropoda y Bivalvia la distribución a nivel de familias; las entidades endémicas, exóticas, invasoras y de importancia sanitaria. Los moluscos relacionados a la cuenca del Plata presentan la mayor riqueza específica. Base de datos: 4 500 registros relevados de las tres colecciones más importantes de la Argentina: MLP, MACN y FML. Además, se incluye información de recolecciones actuales y localidades citadas por otros autores. Hasta el presente han sido descritas 166 especies. De ellas 101 pertenecen a 10 familias de Gastropoda y 65 a 7 de Bivalvia. Las familias que presentan mayor riqueza específica son Lithoglyphidae (22 y Sphaeriidae (25, respectivamente. Sphaeriidae, Cochliopidae, Chilinidae y Lymnaeidae se distribuyen prácticamente en todo el país. Erodonidae y Solecurtidae se registran en ambientes mixohalinos de la provincia de Buenos Aires. Thiaridae y Glacidorbiidae presentan una distribución muy restringida. Especies endémicas de la Argentina: Gastropoda: Ampullariidae (1, Cochliopidae (10, Lithoglyphidae (11, Thiariidae (3, Chilinidae (11, Lymnaeidae (2 y Physidae (2?; Bivalvia: Hyriidae (1?; Etheriidae (1? y Sphaeriidae (10. Especies de interés sanitario: propagadoras de: Esquistosomiasis, Biomphalaria peregrina, B. straminea y B. tenagophila (Planorbidae; Fasciolasis, Lymnaea viatrix y L. columnella (Lymnaeidae; y dermatitis esquistosómicas, Chilina gibbosa y C. fluminea (Chilinidae. Especies de origen asiático: Corbicula fluminea (Corbiculidae y Limnoperna fortunei (Mytilidae. Es prioritaria la formación de áreas protegidas para la conservación de especies endémicas, especialmente de la Mesopotamia Argentina.Latin American Malacology. Freshwater Mollusks from Argentina. A report and an updated list with comments on the species of freshwater molluscs of

Toxicity of a traditional molluscicide to asian clam veligers

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Layhee, Megan J.; ,; Miho Yoshioka,; Bahram Farokhkish,; ,; Gross, Jackson A.; Sepulveda, Adam J.

2014-01-01

Aquaculture and hatchery industries are in need of effective control methods to reduce the risk of spreading aquatic invasive species, such as the Asian clam Corbicula fluminea, through aquaculture and hatchery activities. The planktonic nature of Asian clam veligers enables this life stage to enter water-based infrastructure undetected, including hatchery trucks used to stock fish. Once in hatchery trucks, veligers can disperse overland and establish in previously uninvaded habitats. As a result, there is a need to develop techniques that result in veliger mortality but do not harm fish. In September 2012, we conducted laboratory trials to determine if a molluscicide (750 mg/L potassium chloride and 25 mg/L formalin) commonly used to kill zebra mussel (Dreissena polymorpha) veligers in hatchery trucks can also effectively kill Asian clam veligers. We exposed Asian clam veligers to this molluscicide for 1, 3, and 5 h in each of two water types: deionized water and filtered lake water. We found ,20% mortality at the 1-h exposure period and 100% mortality at both the 3-h and 5-h exposure periods, regardless of water type. This laboratory study represents an important step toward reducing the spread of Asian clams by aquaculture facilities.

Effects of Freshwater Clam Extract Supplementation on Time to Exhaustion, Muscle Damage, Pro/Anti-Inflammatory Cytokines, and Liver Injury in Rats after Exhaustive Exercise

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Kuang-Wen Liao

2013-03-01

Full Text Available The potent anti-inflammatory activities and tissue-protective effects of freshwater clams (Corbicula fluminea have been well reported. The aim of this study was to determine the effects of freshwater clam extract (FCE supplementation on time to exhaustion, muscle damage, pro- and anti-inflammatory cytokines, and liver injury in rats after exhaustive exercise. Thirty-two rats were divided into four groups: sedentary control (SC; SC group with FCE supplementation (SC+FCE; exhaustive exercise (E; and E group with FCE supplementation (E+FCE. The SC+FCE and E+FCE groups were treated with gavage administration of 20 mg/kg for seven consecutive days. Blood samples were collected for the evaluation of biochemical parameters. The cytokine levels of TNF-α and IL-10 were also examined. Twenty-four hours after exhaustive exercise, the rat livers were removed for H & E staining. The FCE supplementation could extend the time to exhaustion in exercised rats. The levels of CPK, LDH, AST, ALT, lactate, TNF-α and H & E stains of the liver injury were significantly decreased in the E+FCE group, but the blood glucose and IL-10 were significantly higher in comparison with the E group. This study suggests that FCE supplementation may improve endurance performance and reduce exercise-induced muscle damage, inflammatory stress and liver injury.

Hábito alimentar e osteologia da boca do peixe-rei, Odontesthes humensis de Buen (Atheriniformes, Atherinopsidae na Lagoa Mirim, Rio Grande do Sul, Brasil Feeding habits and mouth osteology of silverside, Odontesthes humensis de Buen (Atheriniformes, Atherinopsidae in the Mirim Lagoon, Rio Grande do Sul, Brazil

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Fábio Lameiro Rodrigues

2001-09-01

Full Text Available Gut contents of 304 individuals of the silverside Odontesthes humensis de Buen, 1953 were analyzed using frequency of occurrence (FO% and gravimetric (P% methods. A total of 207 individuals (68.1% had some food itens in the gut, while 97 individuals (31.9% had empty guts. The silverside Odontesthes humensis has presented a benthic carnivorous diet, preying mainly on molluscs and arthropods. The molluscs Heleobia sp. (FO = 61.35% and Corbicula fluminea (Müller, 1774 (FO = 57.97% were the most frequent itens, followed by Neocorbicula limosa (Maton, 1811 (FO = 17.39%. Among the arthropods, the coleoptera insects (FO= 18.84% were dominant followed by, insect larvae (FO = 6.76%, the crustacean Palaemonetes argentinus Nobili, 1901 (FO = 1.93% and isopods (FO = 1.45%. Vegetal remains, organic matter and digested fish were grouped due to low frequency (FO = 9.13% being considered occasional. Juvenile fed mainly on insect larvae and moluscs, while the adults preferred molluscs and coleoptera. On the description of its feeding apparatus the importance of a protrusible upper jaw was observed, being important on the capture of prey in inaccessible places. A protrusible mouth and the format of the pharingean plates, are important morphological characters that assist on the capture and handling of prey. The molariform shaped pharingean teeth help break hard food items, as shells and carapaces.

Zebra mussels (Dreissena polymorpha) as a biomonitor of trace elements along the southern shoreline of Lake Michigan.

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Shoults-Wilson, W Aaron; Elsayed, Norhan; Leckrone, Kristen; Unrine, Jason

2015-02-01

The invasive zebra mussel (Dreissena polymorpha) has become an accepted biomonitor organism for trace elements, but it has yet to be studied along the Lake Michigan shoreline. Likewise, the relationships between tissue concentrations of elements, organism size, and sediment concentrations of elements have not been fully explained. The present study found that a variety of allometric variables such as length, dry tissue mass, shell mass, organism condition indices, and shell thickness index were useful in explaining intrasite variability in elemental concentrations. The flesh condition index (grams of tissue dry mass per gram of shell mass) explained variability at the most sites for most elements. Once allometric intrasite variability was taken into account, additional significant differences were found between sites, although the net effect was small. Significant positive relationships between sediment and tissue concentrations were found for Pb and Zn, with a significant negative relationship for Cd. It was also found that Cu and Zn concentrations in tissues increased significantly along the shoreline in the southeasterly direction, whereas Hg increased in a northwesterly direction. Opportunistic sampling found that zebra mussels accumulate significantly higher concentrations of nearly all elements analyzed compared to Asian clams (Corbicula fluminea) at the same site. The present study demonstrates the need to fully explain natural sources of variability before using biomonitors to explain spatial distributions of trace elements. © 2014 SETAC.

Seasonal food habits of introduced blue catfish in Lake Oconee, Georgia

Science.gov (United States)

Jennings, Cecil A.; Mitchell, Geoffrey E.; Nelson, Chris

2018-01-01

Blue catfish (Ictalurus furcatus) are native to the Coosa River drainage in northwest Georgia but have been widely introduced outside of this range including Lake Oconee, a 7677-ha impoundment on the Oconee River in central Georgia. Blue catfish abundance and growth rates have increased dramatically since their introduction in Lake Oconee, but their food habits are unknown. Therefore, food habits of blue catfish in this impoundment were determined by examining the stomachs of 808 specimens in the reservoir’s upper and lower regions across all seasons from summer 2012 to summer 2013. Diet was summarized using the Relative Importance of specific prey by weight. In the upper region of the reservoir, Asian clams (Corbicula fluminea) were the dominant prey item during the summer (75.7%), fall (66.4%), and winter (37.6%); whereas crappie (Pomoxis spp.) was the dominant prey item in the spring (38.7%). Asian clams also were the dominant prey items in the lower region during the fall (68.4%), winter (33.9%), and spring (36.4%). Blue catfish seemed to feed opportunistically on seasonally abundant prey items in both the upper riverine and lower lacustrine portions of the reservoir. Of the many sportfishes in the reservoir, only crappie was an important prey item, and then only in the upper region during the spring. Our results do not support concerns that blue catfish are an apex predator that would decimate the sportfish assemblage in this recently colonized reservoir.

Microplastics in Taihu Lake, China.

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Su, Lei; Xue, Yingang; Li, Lingyun; Yang, Dongqi; Kolandhasamy, Prabhu; Li, Daoji; Shi, Huahong

2016-09-01

In comparison with marine environments, the occurrence of microplastics in freshwater environments is less understood. In the present study, we investigated microplastic pollution levels during 2015 in Taihu Lake, the third largest Chinese lake located in one of the most developed areas of China. The abundance of microplastics reached 0.01 × 10(6)-6.8 × 10(6) items/km(2) in plankton net samples, 3.4-25.8 items/L in surface water, 11.0-234.6 items/kg dw in sediments and 0.2-12.5 items/g ww in Asian clams (Corbicula fluminea). The average abundance of microplastics was the highest in plankton net samples from the southeast area of the lake and in the sediments from the northwest area of the lake. The northwest area of the lake was the most heavily contaminated area of the lake, as indicated by chlorophyll-α and total phosphorus. The microplastics were dominated by fiber, 100-1000 μm in size and cellophane in composition. To our best knowledge, the microplastic levels measured in plankton net samples collected from Taihu Lake were the highest found in freshwater lakes worldwide. The ratio of the microplastics in clams to each sediment sample ranged from 38 to 3810 and was negatively correlated to the microplastic level in sediments. In brief, our results strongly suggest that high levels of microplastics occurred not only in water but also in organisms in Taihu Lake. Copyright © 2016 Elsevier Ltd. All rights reserved.

Fluidized bed ash and passive treatment reduce the adverse effects of acid mine drainage on aquatic organisms.

Science.gov (United States)

Porter, Clint M; Nairn, Robert W

2010-10-15

Elevated concentrations of acidity and metals in acid mine drainage (AMD) may be effectively addressed by active and passive treatment technologies. However, typical evaluations consider only chemical water quality with little if any regard for biological metrics. Robust evaluations including both chemical and biological indicators of water quality improvement are needed. In this study, injection of alkaline fluidized bed ash (FBA) into a flooded underground coal mine was coupled with a five-cell passive treatment system to ameliorate an abandoned AMD discharge in eastern Oklahoma. The passive system included process units promoting both aerobic and anaerobic treatment mechanisms. Resulting water quality changes and biological responses were evaluated. Organisms of two distinct functional groups (the filter-feeding mollusk Corbicula fluminea and the wide-spectrum feeding fish Lepomis macrochirus) were exposed to mine waters in several treatment cells. The combination of treatment technologies was hypothesized to limit potential negative effects on these aquatic organisms. Tissues were harvested and analyzed for concentrations of several metals (Al, Fe, Mn, Mg, Ca, Ni, Cu and Zn) of interest. Organismal responses, such as hepatosomatic index, condition factor, and condition index, did not vary significantly among organisms exposed within different treatment cells when compared to non-AMD impaired waters. Metal tissue accumulation trends, compared to aqueous concentrations, were observed for Fe, Ni and Zn. Exposure experiments with these two organisms indicated that FBA introductions coupled with passive treatment decreased the potential adverse effects of AMD to biological systems. Copyright © 2010 Elsevier B.V. All rights reserved.

Microcystin uptake and biochemical responses in the freshwater clam Corbicula leana P. exposed to toxic and non-toxic Microcystis aeruginosa: Evidence of tolerance to cyanotoxins.

Science.gov (United States)

Pham, Thanh-Luu; Shimizu, Kazuya; Dao, Thanh-Son; Hong-Do, Lan-Chi; Utsumi, Motoo

2015-01-01

We investigated the accumulation and adverse effects of toxic and non-toxic Microcystis in the edible clam Corbicula leana . Treated clams were exposed to toxic Microcystis at 100 μg of MC (microcystin)-LR eq  L -1 for 10 days. The experimental organism was then placed in toxin-free water and fed on non-toxic Microcystis for the following 10 days for depuration. Filtering rates (FRs) by C. leana of toxic and non-toxic Microcystis and of the green alga Chlorella vulgaris as a control were estimated. Adverse effects were evaluated though the activity of catalase (CAT), superoxide dismutase (SOD) and glutathione S-transferase (GST). Clam accumulated MCs (up to 12.7 ± 2.5 μg g -1 dry weight (DW) of free MC and 4.2 ± 0.6 μg g -1 DW of covalently bound MC). Our results suggest that although both toxic and non-toxic cyanobacteria caused adverse effects by inducing the detoxification and antioxidant defense system, the clam was quite resistant to cyanotoxins. The estimated MC concentration in C. leana was far beyond the World Health Organization's (WHO) provisional tolerable daily intake (0.04 μg kg -1  day -1 ), suggesting that consuming clams harvested during cyanobacterial blooms carries a high health risk.

Microcystin uptake and biochemical responses in the freshwater clam Corbicula leana P. exposed to toxic and non-toxic Microcystis aeruginosa: Evidence of tolerance to cyanotoxins

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Thanh-Luu Pham

2015-01-01

Full Text Available We investigated the accumulation and adverse effects of toxic and non-toxic Microcystis in the edible clam Corbicula leana. Treated clams were exposed to toxic Microcystis at 100 μg of MC (microcystin-LReq L−1 for 10 days. The experimental organism was then placed in toxin-free water and fed on non-toxic Microcystis for the following 10 days for depuration. Filtering rates (FRs by C. leana of toxic and non-toxic Microcystis and of the green alga Chlorella vulgaris as a control were estimated. Adverse effects were evaluated though the activity of catalase (CAT, superoxide dismutase (SOD and glutathione S-transferase (GST. Clam accumulated MCs (up to 12.7 ± 2.5 μg g−1 dry weight (DW of free MC and 4.2 ± 0.6 μg g−1 DW of covalently bound MC. Our results suggest that although both toxic and non-toxic cyanobacteria caused adverse effects by inducing the detoxification and antioxidant defense system, the clam was quite resistant to cyanotoxins. The estimated MC concentration in C. leana was far beyond the World Health Organization's (WHO provisional tolerable daily intake (0.04 μg kg−1 day−1, suggesting that consuming clams harvested during cyanobacterial blooms carries a high health risk.

Mercury bioaccumulation along food webs in temperate aquatic ecosystems colonized by aquatic macrophytes in south western France.

Science.gov (United States)

Gentès, Sophie; Maury-Brachet, Régine; Guyoneaud, Rémy; Monperrus, Mathilde; André, Jean-Marc; Davail, Stéphane; Legeay, Alexia

2013-05-01

Mercury (Hg) is considered as an important pollutant for aquatic systems as its organic form, methylmercury (MeHg), is easily bioaccumulated and bioamplified along food webs. In various ecosystems, aquatic periphyton associated with macrophyte was identified as an important place for Hg storage and methylation by microorganisms. Our study concerns temperate aquatic ecosystems (South Western France) colonized by invasive macrophytes and characterized by high mercury methylation potentials. This work establishes original data concerning Hg bioaccumulation in organisms (plants, crustaceans, molluscs and fish) from five contrasting ecosystems. For low trophic level species, total Hg (THg) concentrations were low (from 27±2ngTHgg(-1)dw in asiatic clam Corbicula fluminea to 418±114ngTHgg(-1)dw in crayfish Procambarus clarkii). THg concentrations in some carnivorous fish (high trophic level) were close to or exceeded the International Marketing Level (IML) with values ranging from 1049±220ngTHgg(-1)dw in pike perch muscle (Sander lucioperca) to 3910±1307ngTHgg(-1)dw in eel muscle (Anguilla Anguilla). Trophic levels for the individuals were also evaluated through stable isotope analysis, and linked to Hg concentrations of organisms. A significant Hg biomagnification (r(2)= 0.9) was observed in the Aureilhan lake, despite the absence of top predator fish. For this site, Ludwigia sp. periphyton, as an entry point of Hg into food webs, is a serious hypothesis which remains to be confirmed. This study provides a first investigation of Hg transfer in the ecosystems of south western France and allows the assessment of the risk associated with the presence of Hg in aquatic food webs. Copyright © 2013 Elsevier Inc. All rights reserved.

Assessing disruption of longitudinal connectivity on macroinvertebrate assemblages in a semiarid lowland river

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Marta Leiva

2017-12-01

Full Text Available Abstract Aim: Our aim in this study was evaluate the effects of flow regulation for irrigation on the macroinvertebrate assemblages in a semiarid river. Methods We sampled two reaches in Dulce River; one placed upstream a weir that diverts flow into a network of irrigation channels and the other downstream that weir, in the assessment of the fluvial discontinuity. We assess the differences among reaches and sites, environmental variables, invertebrate density, richness and Shannon-Wiener index applying non-parametric analyses of variance Kruskal Wallis. The similarity percentage analysis (SIMPER was used to identify which species contributed to the dissimilarities on macroinvertebrate assemblage structure. Canonical Correspondence Analysis (CCA was performed with the total set of samples to explore macroinvertebrate distribution in reaches and associations of the assemblages with habitat variables. Results The density, richness and Shannon index values did not show differences between the reaches located upstream and downstream. Beta diversity (Whittaker was 0.72 among upstream sites, 0.56 among downstream sites and higher species turnover (0.73 was obtained between both reaches. The Canonical Correspondence Analysis explained 46.71% of the variance differentiating upstream sites explained by higher values of organic matter of bottom sediments and discharge, high density of Nais communis, Bothrioneurum americanum, Pelomus, Stephensoniana trivandrana, Pristina menoni, P. jenkinae, P.longidentata, P. americana, Dero obtusa, Endotribelos, Heleobia and Turbellaria. The downstream sites were associated to coarser substratum and higher density of Lopescladius, Polypedilum, Cricotopus, Thienamaniella, Cryptochironomus, Baetidae, Nematoda and Corbicula fluminea. Conclusions The low-flow disturbance had effects on the composition of the benthic invertebrate assemblages, but attributes (such as density and richness showed a lower variability probably

Is the Ghost of Waste Management's Past Coming Back to Haunt Us In Our Seafood?

Science.gov (United States)

Rochman, C. M.; Tahir, A.; Serrato, S.; Williams, S.; Baxa, D.; Lam, R.; Teh, C.; Miller, J.; Werorilangi, S.; Teh, S.

2016-02-01

Plastic debris is recognized globally as a persistent contaminant, littered across multiple habitats worldwide. Most striking is its occurrence in wildlife. Plastic has been recovered from hundreds of species across multiple trophic levels and in animals we consider seafood. This has led policy-makers to ask about the extent that our seafood is contaminated with plastic debris and associated contaminants. To help address these policy-relevant and emerging scientific questions, we first measured the simple presence of anthropogenic debris in many different species of fish and one species of shellfish sold as seafood at local fish markets in Half Moon Bay, California, USA and Makassar, Sulawesi, Indonesia. We found anthropogenic debris in roughly 25% of all animals purchased, demonstrating that some seafood items are contaminated with plastic debris, including some that we consume whole (e.g., anchovies and oysters). Next, to understand if plastic debris can act as a vector for organic pollutants to move through the food chain and indirectly into the meat of fish at higher trophic levels, we designed a laboratory dietary exposure to measure the bioaccumulation of sorbed PCBs in Asian clams (Corbicula fluminea) and the biomagnifications in white sturgeon (Acipenser transmontanus). Asian clams were exposed for 30 days to separate treatments of microplastic (polyethylene terephthalate, polyethylene, polyvinyl chloride and polystyrene) with and without sorbed PCBs. Next, diets were formulated using purified ingredients and clams from the first exposure and fed to their predators (sturgeon) for 30 days. Chemical analyses, allowing us to understand how chemical contaminants from plastics move through food chains, will be presented. Combined, this work demonstrates the presence of plastic debris in seafood and will help us understand whether plastic acts as a vector for chemicals to transfer through aquatic foodwebs, including our own.

Distribución del género Diplodon (Mollusca: Bivalvia: Hyriidae en territorio Argentino mediante el uso de Colecciones Biológicas

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Santiago Hernán Torres

2013-10-01

Full Text Available Los bivalvos nacaríferos dulciacuícolas (“náyades”, son especies infaunales, endémicas de la RegiónNeotropical, pertenecientes a las familias Hyriidae (Swaison, 1840 y Etheriidae (Swaison, 1840. La alteración del ambiente y la competencia con especies invasoras como Corbicula fluminea (Müller, 1774 y Limnoperna fortunei (Dunker, 1857, impactan sobre las poblaciones naturales. En esta comunicación, se presenta el inicio de un Proyecto de investigación sobre la distribución geográfica de las especies del género Diplodon en la Argentina. Estas especies son un componente importante de la infauna de los cuerpos lóticos y lénticos, viviendo en fondos limosos, limo-arenosos, excepcionalmente en sustratos duros, con un régimen nutricio filtrador, teniendo un papel importante como recicladores de materia orgánica. Conocer la distribución de los bivalvos pertenecientes al género Diplodon en el territorio Argentino permitirá el reconocimiento de potenciales áreas prioritarias para su conservación. Sobre la base de la bibliografía disponible y los ejemplares de las especies del genero Diplodon depositados en la Colección Malacológica del Museo de La Plata (FCNyM-UNLP, se confeccionó una matriz de datos que incluye la identificación del ejemplar, la colección en que se encuentra depositado, el número de catálogo, la localidad y la fecha de colecta. Cada localidad fue ubicada mediante el uso de cartas geográficas de Argentina y revisiones bibliográficas en imágenes satelitales de GoogleEarth, asignando las coordenadas para cada punto. Como resultado del trabajo se obtiene la distribución de estas especies nativas y se discute el grado de solapamiento con las dos especies de bivalvos invasores y el impacto de actividades humanas. 

Multi-contamination (heavy metals, polychlorinated biphenyls and polycyclic aromatic hydrocarbons) of littoral sediments and the associated ecological risk assessment in a large lake in France (Lake Bourget).

Science.gov (United States)

Lécrivain, Nathalie; Aurenche, Vincent; Cottin, Nathalie; Frossard, Victor; Clément, Bernard

2018-04-01

The lake littoral sediment is exposed to a large array of contaminants that can exhibit significant spatial variability and challenge our ability to assess contamination at lake scale. In this study, littoral sediment contamination was characterized among ten different sites in a large peri-alpine lake (Lake Bourget) regarding three groups of contaminants: 6 heavy metals, 15 polycyclic aromatic hydrocarbons and 7 polychlorinated biphenyls. The contamination profiles significantly varied among sites and differed from those previously reported for the deepest zone of the lake. An integrative approach including chemical and biological analyses was conducted to relate site contamination to ecological risk. The chemical approach consisted in mean PEC quotient calculation (average of the ratios of the contaminants concentration to their corresponding Probable Effect Concentration values) and revealed a low and heterogeneous toxicity of the contaminant mixture along the littoral. Biological analysis including both laboratory (microcosm assays) and in situ (Acetylcholine Esterase (AChE) and Glutathione S-Transferase (GST) activity measurements) experiments highlighted significant differences among sites both in the field and in laboratory assays suggesting a spatial variation of the biota response to contamination. Linear regressions were performed between mean PEC quotients and biological results to assess whether littoral ecological risk was explained by the contamination profiles. The results highly depended on the study benthic or pelagic compartment. Regarding autochthonous Corbicula fluminea, no significant relationship between mean PEC quotients and biomarker activity was found while a significant increase in AChE was observed on autochthonous chironomids, suggesting different stress among benthic organisms. Both AChE and GST in caged pelagic Daphnia magna showed a significant positive relationship with mean PEC quotients. This study underlines the importance of

Uranium(VI) speciation: modelling, uncertainty and relevance to bioavailability models. Application to uranium uptake by the gills of a freshwater bivalve; Speciation de l'uranium(6), modelisation, incertitude et implication pour les modeles de biodisponibilite. Application a l'accumulation dans les branchies d'un bivalve d'eau douce

Energy Technology Data Exchange (ETDEWEB)

Denison, F.H

2004-07-01

The effects of varying solution composition on the interactions between uranium(VI) and excised gills of the freshwater bivalve Corbicula fluminea have been investigated in well defined solution media. A significant reduction in the uptake of uranium was observed on increasing the concentrations of the uranium complexing ligands citrate and carbonate. Saturation kinetics as a function of uranium concentration at a pH value of 5.0 were observed, indicating that the uptake of uranium is a facilitated process, probably involving one or several trans-membrane transport systems. A relatively small change in the uptake of uranium was found as a function of pH (factor of ca. 2), despite the extremely large changes to the solution speciation of uranium within the range of pH investigated (5.0 - 7.5). A comprehensive review of the thermodynamic data relevant to the solution composition domain employed for this study was performed. Estimates of the uncertainties for the formation constants of aqueous uranium(VI) species were integrated into a thermodynamic database. A computer program was written to predict the equilibrium distribution of uranium(VI) in simple aqueous systems, using thermodynamic parameter mean-values. The program was extended to perform Monte Carlo and Quasi Monte Carlo uncertainty analyses, incorporating the thermodynamic database uncertainty estimates, to quantitatively predict the uncertainties inherent in predicting the solution speciation of uranium. The use of thermodynamic equilibrium modelling as a tool for interpreting the bioavailability of uranium(VI) was investigated. Observed uranium(VI) uptake behaviour was interpreted as a function of the predicted changes to the solution speciation of uranium. Different steady-state or pre-equilibrium approaches to modelling uranium uptake were tested. Alternative modelling approaches were also tested, considering the potential changes to membrane transport system activity or sorption characteristics on

Predation on exotic zebra mussels by native fishes: Effects on predator and prey

Science.gov (United States)

Magoulick, D.D.; Lewis, L.C.

2002-01-01

1. Exotic zebra mussels, Dreissena polymorpha, occur in southern U.S. waterways in high densities, but little is known about the interaction between native fish predators and zebra mussels. Previous studies have suggested that exotic zebra mussels are low profitability prey items and native vertebrate predators are unlikely to reduce zebra mussel densities. We tested these hypotheses by observing prey use of fishes, determining energy content of primary prey species of fishes, and conducting predator exclusion experiments in Lake Dardanelle, Arkansas. 2. Zebra mussels were the primary prey eaten by 52.9% of blue catfish, Ictalurus furcatus; 48.2% of freshwater drum, Aplodinotus grunniens; and 100% of adult redear sunfish, Lepomis microlophus. Blue catfish showed distinct seasonal prey shifts, feeding on zebra mussels in summer and shad, Dorosoma spp., during winter. Energy content (joules g-1) of blue catfish prey (threadfin shad, Dorosoma petenense; gizzard shad, D. cepedianum; zebra mussels; and asiatic clams, Corbicula fluminea) showed a significant species by season interaction, but shad were always significantly greater in energy content than bivalves examined as either ash-free dry mass or whole organism dry mass. Fish predators significantly reduced densities of large zebra mussels (>5 mm length) colonising clay tiles in the summers of 1997 and 1998, but predation effects on small zebra mussels (???5 mm length) were less clear. 3. Freshwater drum and redear sunfish process bivalve prey by crushing shells and obtain low amounts of higher-energy food (only the flesh), whereas blue catfish lack a shell-crushing apparatus and ingest large amounts of low-energy food per unit time (bivalves with their shells). Blue catfish appeared to select the abundant zebra mussel over the more energetically rich shad during summer, then shifted to shad during winter when shad experienced temperature-dependent stress and mortality. Native fish predators can suppress adult zebra

Uranium(VI) speciation: modelling, uncertainty and relevance to bioavailability models. Application to uranium uptake by the gills of a freshwater bivalve

International Nuclear Information System (INIS)

Denison, F.H.

2004-07-01

The effects of varying solution composition on the interactions between uranium(VI) and excised gills of the freshwater bivalve Corbicula fluminea have been investigated in well defined solution media. A significant reduction in the uptake of uranium was observed on increasing the concentrations of the uranium complexing ligands citrate and carbonate. Saturation kinetics as a function of uranium concentration at a pH value of 5.0 were observed, indicating that the uptake of uranium is a facilitated process, probably involving one or several trans-membrane transport systems. A relatively small change in the uptake of uranium was found as a function of pH (factor of ca. 2), despite the extremely large changes to the solution speciation of uranium within the range of pH investigated (5.0 - 7.5). A comprehensive review of the thermodynamic data relevant to the solution composition domain employed for this study was performed. Estimates of the uncertainties for the formation constants of aqueous uranium(VI) species were integrated into a thermodynamic database. A computer program was written to predict the equilibrium distribution of uranium(VI) in simple aqueous systems, using thermodynamic parameter mean-values. The program was extended to perform Monte Carlo and Quasi Monte Carlo uncertainty analyses, incorporating the thermodynamic database uncertainty estimates, to quantitatively predict the uncertainties inherent in predicting the solution speciation of uranium. The use of thermodynamic equilibrium modelling as a tool for interpreting the bioavailability of uranium(VI) was investigated. Observed uranium(VI) uptake behaviour was interpreted as a function of the predicted changes to the solution speciation of uranium. Different steady-state or pre-equilibrium approaches to modelling uranium uptake were tested. Alternative modelling approaches were also tested, considering the potential changes to membrane transport system activity or sorption characteristics on

Conséquences industrielles et écologiques de l'introduction de nouvelles espèces dans les hydrosystèmes continentaux : la moule zébrée et autres espèces invasives

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KHALANSKI M.

1997-01-01

Full Text Available Les eaux de surface sont prélevées pour divers usages industriels, parmi lesquels la production d'énergie électrique représente une large part. Dans les circuits d'eau brute se fixent de nombreuses espèces d'organismes aquatiques, qui perturbent le fonctionnement des installations et sont susceptibles d'entraîner l'indisponibilité de certaines d'entre elles. Dans certains cas, l'irruption de nouvelles espèces pose un problème grave à l'industrie. L'introduction de deux espèces de moules zébrées (genre Dreissena dans les Grands Lacs américains, puis leur extension progressive vers le sud des États-Unis au cours des dernières années, se chiffre par un dommage pour l'industrie estimé à cinq milliards de dollars par an en 2000. L'impact écologique de la moule zébrée en Amérique du Nord a fait l'objet de nombreux travaux ; dans la phase d'extension rapide de l'espèce, il semble significatif. En Europe, la moule zébrée constitue aussi une menace pour les circuits industriels ; c'est pourquoi cette espèce a fait l'objet de nombreuses études, notamment en France sur la Seine, le Rhône et la Moselle. Deux nouvelles espèces invasives sont récemment apparues dans les cours d'eau européens : il s'agit du clam asiatique Corbicula fluminea et d'un amphipode : Corophium curvispinum. Elles s'ajoutent à la liste faunistique des organismes observés dans les circuits de centrales thermiques installées sur les cours d'eau français : spongiaires, hydraires, bryozoaires, mollusques. Pour assurer la disponibilité des circuits, il faut pouvoir contrôler le développement de ces espèces ; ce qui implique une connaissance approfondie de leur biologie et de leur écologie. Les méthodes de lutte actuellement mises en oeuvre au plan industriel, ou qui sont à l'étude, sont brièvement passées en revue.

Assessing off-site impacts of wildfires on aquatic organisms using in-situ assays

Science.gov (United States)

Ré, Ana; Saraiva, MariaJoão; Puga, João; Campos, Isabel; Pereira, Joana; Keizer, Jacob; Goncalves, Fernando; Abrantes, Nelson

2017-04-01

Wildfires have been recognized as an important source of diffuse pollution to aquatic systems, particularly through the production and transport of pyrolytic substances such as polycyclic aromatic hydrocarbons (PAHs) and metals associated to ash/soil loads. However, the effects of these compounds from recently burnt areas on the aquatic biota have been largely ignored. Hence, the main goal of this study was to assess the ecotoxicological effects of wildfires in aquatic systems through the use of in situ experiments. In this sense, five sites were selected in a catchment partially burnt: two in the main water course - Ceira river (Miranda do Corvo, Portugal), being one located upstream (RUS) and the other downstream (RDS) the burnt area; two in tributary streams within the burnt area (SUS and SDS); and finally one in a stream located in the unburnt part of the catchment (CS). During the first post-fire rainfall events, distinct organisms, including the water flea Daphnia magna, the freshwater shrimp Atyaephyra desmaresti, the freshwater clam Corbicula fluminea and the mosquitofish Gambusia holbrooki were exposed in situ, in all five sites, using dedicated test chambers. After four days of field exposition, the mortality and post-exposure feeding inhibition were evaluated. Feeding depression after exposure time was selected as a sub-lethal endpoint because it is a quick, sensitive and ecologically relevant indicator of toxic stress. The results showed negligible mortality for all the species and sites, thus lethality was not sensitive to discern impacts among the assessed sites. Conversely, the sub-lethal post-exposure feeding inhibition endpoint, revealed a decrease of feeding rate, in streams within the burnt area (SUS and SDS), that seemed to be the most affected places in the study area. Conversely, the sites outside the burnt area, both on river (RUS) and on the stream (CS), showed no adverse effects in this endpoint. Hence, the current results pointed-out that

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

Handling sticky resin by stingless bees (Hymenoptera, Apidae

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Markus Gastauer

2011-06-01

Full Text Available For their nest defense, stingless bees (Meliponini collect plant resins which they stick on intruders like ants or cleptobiotic robber bees causing their immobilization. The aim of this article is to identify all parts of stingless bee workers contacting these sticky resins. Of special interest are those body parts with anti-adhesive properties to resin, where it can be removed without residues. For that, extensive behavioral observations during foraging flight, handling and application of the resin have been carried out. When handling the resin, all tarsi touch the resin while walking above it. For transportation from plants to the nest during foraging flight, the resin is packed to the corbicula via tarsi and basitarsi of front and middle legs. Once stuck to the resin or after the corbicula had been unloaded, the bee's legs have to be cleaned thoroughly. Only the tips of the mandibles, that form, cut and apply the sticky resin, seem to have at least temporarily resin-rejecting properties.

The use of polliniferous resources by Melipona capixaba, an endangered stingless bee species.

Science.gov (United States)

Serra, Bruna Danielle Vieira; da Luz, Cynthia Fernandes Pinto; Campos, Lucio Antonio de Oliveira

2012-01-01

Abstract Pollen types present in samples from corbiculae of Melipona capixaba (Moure and Camargo) (Hymenoptera: Apidae: Meliponina) worker bees were analyzed, as well as pollen samples from food pots inside the hives in three sites located at the bees' original habitat. The aim was to find out the sources used as a trophic resource by this species. The dominant pollen grains in the spectrum of the samples belonged to the families Myrtaceae and Melastomataceae. Eucalyptus was the most frequent pollen type in the corbiculae in Conceição do Castelo municipality; Eucalyptus, Myrcia, and Melastomatacea/Combretaceae in the Fazenda do Estado district; and Eucalyptus and Myrcia in the São Paulo de Aracê district, both in the Domingos Martins municipality. Eucalyptus and Melastomataceae/Combretaceae were the predominant pollen types in the food pots. Eucalyptus was the most prevalent type all year round or most of the year. The most common pollen types in the months that Eucalyptus was not present or dominant in the samples were of remaining native forest species, "ruderal" (field) plants, fruit-bearing plants, and introduced ornamental plants.

Spatial and temporal distribution of the zoobenthos community during the filling up period of Porto Primavera Reservoir (Paraná River, Brazil

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A. Jorcin

Full Text Available This study is part of the limnological monitoring undertaken by the Energy Company of the State of São Paulo (CESP during the filling up process of the Porto Primavera Reservoir (Hydroelectric Power Plant Engenheiro Sérgio Motta. This reservoir, located in the high Paraná River between the States of São Paulo and Mato Grosso do Sul, is the fourth largest in the country. The first filling up phase started in December 1998 and the second phase in March 2001. Samples for benthic community and sediment characteristics analysis were quarterly collected between August of 1999 and November 2001 and also in August of 2002 (11 sampling campaigns. Samplings were carried out at 13 stations distributed in the reservoir, and at one point located downstream of the dam. 128 invertebrate taxa were identified, being Mollusca, Annelida, Insecta and Nematoda the dominant groups during almost the whole study period. Insecta was the best represented class (9 different orders, and Diptera contributed with higher number of taxa, 63. The exotic species of bivalve Corbicula fluminea was recorded in all sampling stations showing its great capacity to colonize new habitats in the neotropical region. Noticeable variations in the fauna density were observed, considering both different periods and locations. The maximum density of organisms (mean value of 7812 ind.m-2 was recorded in the center of the reservoir, and the minimum (mean value 9 ind.m-2 in the more lacustrine area near the dam. The greatest species richness per sample (24 taxa was observed in the reservoir upstream (fluvial zone. The maximum diversity (Shannon-Wiener Index per station/period, 3.82 and 3.86 bits.ind-1, were calculated in the transitional river/reservoir zone during the beginning (August 1999 and in the reservoir central zones in the end (August 2002 of the filling up period, respectively. There was no clear relation between the distribution of the different faunistic groups and the sediment

Survey of chemical contaminants in the Hanalei River, Kaua'i, Hawai'i, 2001

Science.gov (United States)

Orazio, Carl E.; May, Thomas W.; Gale, Robert W.; Meadows, John C.; Brumbaugh, William G.; Echols, Kathy R.; Steiner, William W.M.; Berg, Carl J.

2007-01-01

The Hanalei River on the island of Kaua'i in Hawai'i was designated an American Heritage River in 1998, providing special attention to natural resource protection, economic revitalization, and historic and cultural preservation. Agricultural, urban, and tourism-related activities are potential sources of contamination within the Hanalei River watershed. The objective of this study was to measure certain persistent organic chemicals and elements in the Hanalei River.During a relatively low-flow period in December of 2001, samples of native Akupa sleeper fish (Eleotris sandwicensis), freshwater Asian clam (Corbicula fluminea), giant mud crab (Scylla serrata), surface water, and stream bed sediment were collected from a lower estuarine reach of the river near its mouth at Hanalei Bay and from an upper reach at the Hanalei National Wildlife Refuge. Samples were analyzed for residues of urban and agricultural chemicals including organochlorine pesticides, polychlorinated biphenyls, polycyclic aromatic hydrocarbons, and elements (including mercury, lead, cadmium, arsenic, and selenium). Organic contaminants were extracted from the samples with solvent, enriched, and then analyzed by gas chromatographic analysis with electron capture or mass spectrometric detection. Samples were acid-digested for semi-quantitative analysis for elements by inductively-coupled plasma-mass spectrometry and for quantitative analysis by atomic absorption spectrophotometry.Concentrations of organochlorine pesticides, polycyclic aromatic hydrocarbons, and polychlorinated biphenyls in biota, surface water, and bed sediment sampled from the Hanalei River ranged from nondetectable to very low levels. Polychlorinated biphenyls were below detection in all samples. Dieldrin, the only compound detected in the water samples, was present at very low concentrations of 1-2 nanograms per liter. Akupa sleeper fish and giant mud crabs from the lower reach ranged from 1 to 5 nanograms per gram (wet weight

The effects of low level chlorination and chlorine dioxide on biofouling control in a once-through service water system

International Nuclear Information System (INIS)

Garrett, W.E. Jr.; Laylor, M.M.

1995-01-01

Continuous chlorination has been successfully used for the control of Corbicula at a nuclear power plant located on the Chattahoochee River in southeastern Alabama, since 1986. The purpose of this study was to investigate further minimization of chlorine usage and determine if chlorine dioxide is a feasible alternative. Four continuous biocide treatments were evaluated for macro and microfouling control effectiveness, operational feasibility, and environmental acceptability. One semi-continuous chlorination treatment was also evaluated for macrofouling control effectiveness. Higher treatment residuals were possible with chlorine dioxide than with chlorination due to the river discharge limitations. At the levels tested, continuous chlorine dioxide was significantly more effective in providing both macro and microfouling control. Semi-continuous chlorination was just as effective as continuous chlorination for controlling macrofouling. The Corbicula treatment programs that were tested should all provide sufficient control for zebra mussels. Chlorine dioxide was not as cost effective as chlorination for providing macrofouling control. The semi-continuous treatment save 50% on chemical usage and will allow for the simultaneous treatment of two service water systems. Chlorite levels produced during the chlorine dioxide treatments were found to be environmentally acceptable. Levels of trihalomethanes in the chlorinated service water were less than the maximum levels allowed in drinking water

The reproductive biology of Lutraria philippinarum (Veneroida: Mactridae and its fishery in the Philippines

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Venus Bantoto

2012-12-01

Full Text Available The Snout Otter Clam, Lutraria philippinarum is a regularly harvested bivalve species for food and also as a source of income in the Philippines. For sustainable supply of this resource in the wild, efficient and effective management strategies are needed, and the evaluation of its reproductive biology and fishery are required. In this study, the reproductive biology and fishery of L. philippinarum in the Philippines were examined monthly from January to December 2010 in North Bais Bay, Manjuyod, Negros Oriental and Philippines. For reproductive biology, otter clams were sampled, and sex ratio (by microscopic observation, size at sexual maturity, shell length (with a vernier caliper, gonad development (by histological examination as resting, developing, mature, spawning and spent and spawning season were determined. Other information such as water temperature, salinity, pH and dissolved oxygen were also measured. To obtain information on the L. philippinarum fishery, interviews were conducted in Negros Oriental, Bohol, Cebu and Sarangani. A total of 677 snout otter clams were sampled. The study showed that L. philippinarum sex ratio was 1:1.15 and showed no significant difference from 1:1 ratio. Males attained its first sexual maturity at 43mm shell length while the females at 46mm. Histological examination on gonad development indicated that gametogenesis, maturation and spawning season of L. philippinarum occurred throughout the year with two spawning peaks, January and June. Changes in water temperature in North Bais Bay may have influenced the spawning peaks of L. philippinarum. Data on the fishery of L. philippinarum revealed that the Catch Per Unit Effort of L. philippinarum in the Philippines ranged from 0.2kg/hr-man to 1.25kg/hr-man suggesting low shell catch. We recommend that some mature individuals have to be left in the population to allow in situ breeding.Lutraria philippinarum es una especie de bivalvo recolectada regularmente para la alimentación y como fuente de ingreso en las Filipinas. Para el suministro sostenible de este recurso en la naturaleza, se necesitan estrategias de manejo efectivas, así como la evaluación de su biología reproductiva y pesquera. Se examinaron estos aspectos mensualmente de enero-diciembre 2010 en North Bais Bay, Manjuyod, Negros Oriental, Filipinas. Se tomó medida del tamaño a la madurez sexual, proporción de sexos (con observación microscópica, longitud de la concha (con calibrador vernier, desarrollo de gónadas (con examinación histológica del descanso, desarrollo, madurez, desove y gasto y época de desove. Para obtener información de la pesquería de L. philippinarum, se realizaron entrevistas en Negros Oriental, Bohol, Cebu y Sarangani. Un total de 677 ostras fueron muestreadas. Se encontró que la proporción de sexos fue 1:1.15 y no se observó diferencia significativa de la proporción 1:1. Los machos alcanzaron la madurez sexual a la longitud de concha de 43mm mientras que las hembras a 46mm. El análisis histológico del desarrollo de las gónodas indicó que la gametogénesis, maduración y desove ocurren durante todo el año con dos picos de desove, enero y junio. Los datos sobre la pesquería revelaron que la captura por unidad de esfuerzo de L. philippinarum osciló entre 0.2kg/h hombre a 1.25kg/h hombre que sugieren baja captura de conchas. Recomendamos que algunos individuos maduros tienen que ser dejados en la población para permitir la reproducción in situ.

Cooling systems

International Nuclear Information System (INIS)

Coutant, C.C.

1978-01-01

Progress on the thermal effects project is reported with regard to physiology and distribution of Corbicula; power plant effects studies on burrowing mayfly populations; comparative thermal responses of largemouth bass from northern and southern populations; temperature selection by striped bass in Cherokee Reservoir; fish population studies; and predictive thermoregulation by fishes. Progress is also reported on the following; cause and ecological ramifications of threadfin shad impingement; entrainment project; aquaculture project; pathogenic amoeba project; and cooling tower drift project

ジンザイ コ ジンコウ イケ ニ オケル ヤマト シジミ ノ

OpenAIRE

大谷, 修司; 辻井, 要介; 江原, 亮; 草田, 和美; 板倉, 俊一; 山口, 啓子; 品川, 明; 秦, 明徳; 中村, 幹雄

2004-01-01

We studied feeding, egestion and digestion of Corbicula japonica in the laboratory. Clams were collected from an artificial shallow pond(20-60 cm deep)near the brackish Lake Jinzai in 2001. Pond water was supplied continuously from Lake Jinzai using a pump. Feces and pseudo-feces of the clams were observed by microscope. Clam pseudo-feces were irregular, wooly, and brown in color when clam fed phytoplankton. These were mainly composed of living micro-algae, detritus, cf. amoebocytes and proto...

Molecular phylogeny of the bivalve superfamily Galeommatoidea (Heterodonta, Veneroida) reveals dynamic evolution of symbiotic lifestyle and interphylum host switching

Science.gov (United States)

2012-01-01

Background Galeommatoidea is a superfamily of bivalves that exhibits remarkably diverse lifestyles. Many members of this group live attached to the body surface or inside the burrows of other marine invertebrates, including crustaceans, holothurians, echinoids, cnidarians, sipunculans and echiurans. These symbiotic species exhibit high host specificity, commensal interactions with hosts, and extreme morphological and behavioral adaptations to symbiotic life. Host specialization to various animal groups has likely played an important role in the evolution and diversification of this bivalve group. However, the evolutionary pathway that led to their ecological diversity is not well understood, in part because of their reduced and/or highly modified morphologies that have confounded traditional taxonomy. This study elucidates the taxonomy of the Galeommatoidea and their evolutionary history of symbiotic lifestyle based on a molecular phylogenic analysis of 33 galeommatoidean and five putative galeommatoidean species belonging to 27 genera and three families using two nuclear ribosomal genes (18S and 28S ribosomal DNA) and a nuclear (histone H3) and mitochondrial (cytochrome oxidase subunit I) protein-coding genes. Results Molecular phylogeny recovered six well-supported major clades within Galeommatoidea. Symbiotic species were found in all major clades, whereas free-living species were grouped into two major clades. Species symbiotic with crustaceans, holothurians, sipunculans, and echiurans were each found in multiple major clades, suggesting that host specialization to these animal groups occurred repeatedly in Galeommatoidea. Conclusions Our results suggest that the evolutionary history of host association in Galeommatoidea has been remarkably dynamic, involving frequent host switches between different animal phyla. Such an unusual pattern of dynamic host switching is considered to have resulted from their commensalistic lifestyle, in which they maintain filter-feeding habits even in symbiotic habitats. The results of the molecular phylogenetic analysis did not correspond with the current taxonomic circumscription. Galeommatidae and Lasaeidae were polyphyletic, and Basterotia, which is traditionally assigned to Cyamioidea, formed a monophyletic clade within Galeommatoidea. PMID:22954375

Molecular phylogeny of the bivalve superfamily Galeommatoidea (Heterodonta, Veneroida reveals dynamic evolution of symbiotic lifestyle and interphylum host switching

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Goto Ryutaro

2012-09-01

Full Text Available Abstract Background Galeommatoidea is a superfamily of bivalves that exhibits remarkably diverse lifestyles. Many members of this group live attached to the body surface or inside the burrows of other marine invertebrates, including crustaceans, holothurians, echinoids, cnidarians, sipunculans and echiurans. These symbiotic species exhibit high host specificity, commensal interactions with hosts, and extreme morphological and behavioral adaptations to symbiotic life. Host specialization to various animal groups has likely played an important role in the evolution and diversification of this bivalve group. However, the evolutionary pathway that led to their ecological diversity is not well understood, in part because of their reduced and/or highly modified morphologies that have confounded traditional taxonomy. This study elucidates the taxonomy of the Galeommatoidea and their evolutionary history of symbiotic lifestyle based on a molecular phylogenic analysis of 33 galeommatoidean and five putative galeommatoidean species belonging to 27 genera and three families using two nuclear ribosomal genes (18S and 28S ribosomal DNA and a nuclear (histone H3 and mitochondrial (cytochrome oxidase subunit I protein-coding genes. Results Molecular phylogeny recovered six well-supported major clades within Galeommatoidea. Symbiotic species were found in all major clades, whereas free-living species were grouped into two major clades. Species symbiotic with crustaceans, holothurians, sipunculans, and echiurans were each found in multiple major clades, suggesting that host specialization to these animal groups occurred repeatedly in Galeommatoidea. Conclusions Our results suggest that the evolutionary history of host association in Galeommatoidea has been remarkably dynamic, involving frequent host switches between different animal phyla. Such an unusual pattern of dynamic host switching is considered to have resulted from their commensalistic lifestyle, in which they maintain filter-feeding habits even in symbiotic habitats. The results of the molecular phylogenetic analysis did not correspond with the current taxonomic circumscription. Galeommatidae and Lasaeidae were polyphyletic, and Basterotia, which is traditionally assigned to Cyamioidea, formed a monophyletic clade within Galeommatoidea.

Atividades de coleta e origem floral do pólen armazenado em colônias de Plebeia saiqui (Holmberg (Hymenoptera, Apidae, Meliponinae no sul do Brasil Collection activities and floral origin of the stored pollcn in colonies of Plebeia saiqui (Holmberg (Hymenoptera, Apidae, Meliponinae in south Brazil

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Raquel A. Pick

2002-03-01

Full Text Available Four colonies of Plebeia saiqui (Holmberg, 1903, of São Francisco de Paula, were studied during the period from October/1998 to October/1999. The counting of the bees was proceeded monthly, differentiated workers that came back with and without pollen in the corbicula. Grains of pollen of pots previously marked were collected monthly and identified. The percentage of the pollen types of the samples was estimated: 20% of Asteraceae, 17% Myrtaceae, 15% type Meliaceae and 10% Euphorbiaceae. The remaining corresponds to other pollen types of small representation, besides those the were no identified. The climatic influence on the pollen collection was analyzed being used simple and multiple regressions. It was verified that in the spring and in the summer the temperature, the solar irradiation and relative humidity were significant for the pollen foraging. During autumn and winter the relative humidity had smaller influence in the pollen collection.

DNA damage in gill cells of Corbicula japonica exposed to natural and anthropogenic stressors

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Valentina Vladimirovna Slobodskova

2015-06-01

The results are presented as the percentage distribution of nuclei in the various damage classes and summarized in an index of DNA integrity or genetic damage index GDI (Cavas, Kohen, 2008: The results from our study showed significant level of DNA damage from the C. japonica which were collected from polluted sites. Unpolluted sites were described as with no or minimal DNA strand breaks. Mollusks collected at polluted areas (estuary Razdolnaya river, lagoon Tihaya showed high levels of DNA damage, GDI is equal to 3.22±0.2 and 3.11±0.7 in gills respectively. C. japonica obtained from a ‘clean’ areas (estuary Artemovka river, estuary Partizanskaya river demonstrate less high level of DNA damage destruction, GDI is equal to 0,6±0,08 and 0,71±0,12 in gills respectively. Lipid peroxidation level was assayed measurement of malondialdehyde (MDA, a decomposition product of polyunsaturated fatty acids hydro peroxides were determined by the TBA reaction. The absorbance was read at 532 nm after removal of substances (TBARS formed was calculated by using an extinction coefficient of 1.56*105 M-1 cm -1 formed per g dry weight. C. japonica sampled at Artemovka estuary, Partizanskaya estuary, Razdolnaya estuary, Tihaya lagoon showed LPX level (3.46±0.59, 5.62±0.82, 12.85±0.52, 15.32±1.13 nmol TBARS/g dry wt in gills respectively. In conclusion, it can be noted that in the course of the experiment we found a clear relationship between the amount of DNA damage and the level of peroxidation products (MDA in the gills of bivalve C. japonica, collected from sites with varying degrees of anthropogenic load. It should be emphasized that the shellfish that live in polluted areas are likely to be in a state of oxidative stress, which is one of the causes the degradation of DNA.

Uptake of γ-emitting radionuclides by aquatic biota exposed to contaminated water before and after passage through the ground

International Nuclear Information System (INIS)

Cushing, C.E.; Rickard, W.H.; Watson, D.G.

1984-01-01

Three experimental systems were designed to investigate the differential accumulation of radionuclides by biota from low-level aqueous effluents after passage through the ground. One system received river water (control), one received dilute low-level radioactive effluents (trench), and the third received the low-level effluents after it had percolated through about 260 m or porous gravel (springs). Biota studied included filamentous green algae, clams (Corbicula), goldfish (Carassius auratus), carp (Cyprinus carpio), and Veronica. Trophic level differences in accumulation of the various radionuclides from the diluted trench water were not consistent but generally followed the pattern algae > goldfish > molluscs > carp. Cobalt-60 was accumulated to the highest level of any radionuclide, and accumulation levels at the three sites were directly related to the concentration of 60 Co in the water. Manganese-54, 59 Fe, and 106 Ru were also accumulated to measurable levels in biota at the springs site indicating their bioavailability after passage through the ground

High resolution modelling of the biogeochemical processes in the eutrophic Loire River (France)

Science.gov (United States)

Minaudo, Camille; Moatar, Florentina; Curie, Florence; Gassama, Nathalie; Billen, Gilles

2016-04-01

released by mineralization of the dead cells. The high resolution of the model allowed understanding some fine temporal scale events, especially during some minor flood events occurring in summer. Paradoxically such events played two opposite roles: first it was disturbing the phytoplankton by diluting the biomass and remobilizing suspended sediments; then, it indirectly re-supplied the system with more available phosphorus, mainly because the washed-out phytoplankton could not assimilate the P available upstream. The model also pointed out the significant role played by Corbicula invasive clams in the river biogeochemical functioning, substantially reducing the phytoplankton biomass, and thus impacting the nutrients, oxygen and carbon cycles. However, the temporal and spatial distribution of Corbicula was questioned, and highlighted the need for data collection on this topic.

Freshwater Clam Extract Ameliorates Triglyceride and Cholesterol Metabolism through the Expression of Genes Involved in Hepatic Lipogenesis and Cholesterol Degradation in Rats

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Thomas Laurent

2013-01-01

Full Text Available The freshwater clam (Corbicula spp. is a popular edible bivalve and has been used as a folk remedy for liver disease in Asia. As a Chinese traditional medicine, it is said that freshwater clam ameliorates alcoholic intoxication and cholestasis. In this study, to estimate the practical benefit of freshwater clam extract (FCE, we compared the effects of FCE and soy protein isolate (SPI on triglyceride and cholesterol metabolism in rats. FCE and SPI lowered serum cholesterol, and FCE tended to reduce serum triglycerides. FCE enhanced fecal sterol excretion and hepatic mRNA levels of CYP7A1 and ABCG5 more substantially than SPI; however, both diets reduced hepatic cholesterol. Both of the diets similarly suppressed liver lipids improved Δ9-desaturated fatty acid profile, and FCE was associated with a reduction in FAS and SCD1 mRNA levels. Hepatic transcriptome analysis revealed that inhibition of lipogenesis-related gene expression may contribute to downregulation of hepatic triglycerides by FCE. FCE would have better potential benefits for preventing metabolic disorders, through greater improvement of metabolism of triglycerides and cholesterol, likely through a mechanism similar to SPI.

Bio-filtration capacity, oxygen consumption and ammonium excretion of Dosinia ponderosa and Chione gnidia (Veneroida: Veneridae) from areas impacted and non-impacted by shrimp aquaculture effluents.

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Ramos-Corella, Karime; Martínez-Córdova, Luis Rafael; Enríquez-Ocaña, Luis Fernando; Miranda-Baeza, Anselmo; López-Elías, José Antonio

2014-09-01

Mollusks are some of the most important, abundant and diverse organisms inhabiting not only aquatic ecosystems, but also terrestrial environments. Recently, they have been used for bioremediation of aquaculture effluents; nevertheless, for that purpose it is necessary to analyze the capacity of a particular species. In this context, an experimental investigation was developed to evaluate the performance of two bivalves C. gnidia and D. ponderosa, collected from areas with or without shrimp aquaculture effluents. For this, the filtration capacity (as clearance rate) as well as the oxygen consumption and ammonia excretion rates were measured following standard methods. The clearance rate was significantly higher for D. ponderosa from impacted areas, when com- pared to C. gnidia, from both areas. Contrarily, the oxygen consumption was greater for C. gnidia from impacted areas compared to D. ponderosa from both areas. The same tendency was observed for the ammonia excretion with the highest rates observed for C. gnidia from impacted areas, whereas no differences were observed among D. ponderosa from both areas. The results suggest that both species developed different strategies to thrive and survive under the impacted conditions; D. ponderosa improved its filtration efficiency, while C. gnidia modified its oxygen consumption and ammonia excretion. We concluded that both species, and particularly D. ponderosa, can be used for bioremediation purposes.

Bio-filtration capacity, oxygen consumption and ammonium excretion of Dosinia ponderosa and Chione gnidia (Veneroida: Veneridae from areas impacted and non-impacted by shrimp aquaculture effluents

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Karime Ramos-Corella

2014-09-01

Full Text Available Mollusks are some of the most important, abundant and diverse organisms inhabiting not only aquatic ecosystems, but also terrestrial environments. Recently, they have been used for bioremediation of aquaculture effluents; nevertheless, for that purpose it is necessary to analyze the capacity of a particular species. In this context, an experimental investigation was developed to evaluate the performance of two bivalves C. gnidia and D. ponderosa, collected from areas with or without shrimp aquaculture effluents. For this, the filtration capacity (as clearance rate as well as the oxygen consumption and ammonia excretion rates were measured following standard methods. The clearance rate was significantly higher for D. ponderosa from impacted areas, when com- pared to C. gnidia, from both areas. Contrarily, the oxygen consumption was greater for C. gnidia from impacted areas compared to D. ponderosa from both areas. The same tendency was observed for the ammonia excretion with the highest rates observed for C. gnidia from impacted areas, whereas no differences were observed among D. ponderosa from both areas. The results suggest that both species developed different strategies to thrive and survive under the impacted conditions; D. ponderosa improved its filtration efficiency, while C. gnidia modified its oxygen consumption and ammonia excretion. We concluded that both species, and particularly D. ponderosa, can be used for bioremediation purposes.

Melitocoria de Zygia racemosa (Ducke Barneby & Grimes por Melipona seminigra merrillae Cockerell, 1919 y Melipona compressipes manaosensis Schwarz, 1932 (Hymenoptera, Meliponina en la Amazonía Central, Brasil Melitocory of Zygia racemosa (Ducke Barneby & Grimes by Melipona seminigra merrillae Cockerell, 1919 and Melipona compressipes manaosensis Schwarz, 1932 (Hymenoptera, Meliponina in Central Amazon, Brazil

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Christinny Giselly Bacelar-Lima

2006-01-01

Full Text Available Durante el periodo de enero a abril de 2005 fueron encontradas semillas de Zygia racemosa, incorporadas al geoprópolis, en el interior de abejas sin aguijón en dos meliponarios experimentales en Manaus - AM. Fue observada intensa actividad de las obreras de M. seminigra merrillae y M. compressipes manaosensis llegando del campo con semillas fijas en las corbículas adheridas con resina y/o saliendo de las colonias con las semillas atrapadas en las mandíbulas. Ochenta semillas fueron recogidas en el interior de las colonias (mezcladas al geoprópolis en los basureros y fisuras y también en el exterior, cerca de la entrada de las colonias, como resultado de la caída de esas semillas de las corbículas durante el vuelo de las obreras. Las semillas fueron plantadas en semilleros para la producción de esquejes y posterior identificación de la especie vegetal. Paralelamente se realizó el rastreo en campo en un radio de aproximadamente 3Km para la confirmación de la dispersión de las semillas, observaciones de comportamiento de las abejas forrajeando y recolección de semillas. Un total de 170 plántulas de Z. racemosa fueron encontradas en los alrededores del meliponario del GPA-INPA y 160 en el meliponario Vale Verde. Esos resultados indican que tanto M. compressipes manaosensis como M. seminigra merrillae recolectan y dispersan las semillas de Z. racemosa.During the period from January to April 2005 seeds of Zygia racemosa were found incorporated in the nest structures, inside the colonies of stingless bee in two experimental meliponaries in Manaus - Am. It was registered an intense activity of the bee-workers of Melipona seminigra merrillae and M. compressipes manaosensis arriving from the field with seeds set in the corbiculae adhered with resin and/or leaving the colonies with the seeds clipped in their jaws. Eighty seeds were collected inside the colonies (mixed with the batume in the litter and/or cracks, and also outside them, near

In situ studies with Asian clams (Carbacula fluminea) detect acid mine drainage and nutrient inputs in low-order streams

International Nuclear Information System (INIS)

Soucek, D. J.; Schmidt, T. S.; Cherry, D. S.

2001-01-01

This study evaluates the correlation between transplanted Asiatic clam and indigenous community responses to acid mine drainage and nutrient loading in first-to-third-order streams, by comparing the toxicological endpoints of clam survival and growth with benthic macro-invertebrate community indices as community responses to both acid mine drainage and nutrient loading. Clam survival was found to be positively correlated with water column pH and negatively correlated with conductivity and metal concentrations. There was also a positive correlation with the relative abundance of the macro-invertebrate Ephemeroptera, the most sensitive taxonomic group, to acid mine drainage in this watershed. No correlation was found between clam growth and acid mine drainage inputs, but there was evidence of positive correlation with nitrate concentrations and the relative abundance of collector-filterer functional feeding groups. These results suggest that clam growth is related to nutrient levels and accurately reflect benthic macro-invertebrate responses to nutrient loading. 28 refs., 5 tabs., 1 fig

Removal of clay by stingless bees: load size and moisture selection.

Science.gov (United States)

Costa-Pereira, Raul

2014-09-01

Some organisms disperse energy, associated with the transportation of resource, which is not necessarily food. Stingless bees of Central Amazonia (Melipona flavolineata and M. lateralis) collect clay in banks along streams for nest building. The moisture of the clay varies along the bank, and bees collect clay from specific location, indicating that there is some sort of preference regarding their selection. This study aims at identifying: if larger bees carry more clay; if there is a preference for moisture of substrates; and if bees are less efficient accumulating and transporting clay when it is wet. In order to do so, I measured the size of the bees and of the pellets of clay found in the corbicula. I set up a field experiment to test substrate preferences. The amount of clay transported, increased exponentially in accordance to the size of the bee, and the preferred substrate was the driest clay. The amount and the efficiency of removal of clay were not affected by the moisture of the substrate. Despite the wet clay being denser, it does not reduce the efficiency of exploitation of the resource, but suggests that bees spend more energy to carry the same quantity of wet clay, which may be the underlying mechanism explaining their preference for removing drier clay.

Morphological and functional characterization of hemocytes from two deep-sea vesicomyid clams Phreagena okutanii and Abyssogena phaseoliformis.

Science.gov (United States)

Tame, Akihiro; Ozawa, Genki; Maruyama, Tadashi; Yoshida, Takao

2018-03-01

, such as dissolved oxygen, hydrogen sulfide concentration, and hydrostatic pressure. In the view of phylogeny of veneroida clams including two vesicomyids, their hemocytes appear to be categorizable into three basic types, with the first containing ERCs and agranulocytes, the second including EGs, and the third comprised of BGs, small eosinophilic granulocytes, and other granulocytes. The present data showed no phagocytic activity of ERCs and a lack of agranulocytes in both vesicomyid species, and when combined with previous reports that other veneroid clams show low or no phagocytic activity, this suggests that ERCs have become evolutionarily differentiated from agranulocytes in the ancestral vesicomyid clam. Copyright © 2018 Elsevier Ltd. All rights reserved.

Removal of clay by stingless bees: load size and moisture selection

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RAUL COSTA-PEREIRA

2014-09-01

Full Text Available Some organisms disperse energy, associated with the transportation of resource, which is not necessarily food. Stingless bees of Central Amazonia (Melipona flavolineata and M. lateralis collect clay in banks along streams for nest building. The moisture of the clay varies along the bank, and bees collect clay from specific location, indicating that there is some sort of preference regarding their selection. This study aims at identifying: if larger bees carry more clay; if there is a preference for moisture of substrates; and if bees are less efficient accumulating and transporting clay when it is wet. In order to do so, I measured the size of the bees and of the pellets of clay found in the corbicula. I set up a field experiment to test substrate preferences. The amount of clay transported, increased exponentially in accordance to the size of the bee, and the preferred substrate was the driest clay. The amount and the efficiency of removal of clay were not affected by the moisture of the substrate. Despite the wet clay being denser, it does not reduce the efficiency of exploitation of the resource, but suggests that bees spend more energy to carry the same quantity of wet clay, which may be the underlying mechanism explaining their preference for removing drier clay.

Dinámica poblacional de Donax dentifer (Veneroida: Donacidae en Bahía Málaga, Pacífico colombiano durante el fenómeno "El Niño" 1997/1998

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José M. Riascos

2002-12-01

Full Text Available Donax dentifer es un bivalvo dominante en comunidades de playa arenosa en la costa del Pacífico colombiano. Se muestreó mensualmente una población de este bivalvo en Bahía Málaga, Pacífico colombiano entre agosto de 1997 y julio de 1998 cuando ocurrió el evento "El Niño" 1997/1998. Se tomaron muestras cuantitativas mensuales usando transectos lineales perpendiculares y paralelos a la línea de costa para determinar la densidad poblacional y realizar una distribución de frecuencias de longitud. Se tomaron también muestras cualitativas mensuales para estudiar la reproducción y establecer relaciones peso-longitud. Se registró la temperatura, oxígeno disuelto, salinidad y pH de la columna de agua en el sitio de muestreo. Adicionalmente se realizó un experimento de marcaje-recaptura para estimar el crecimiento de la población. Los resultados indican que la población tiene un ciclo de reproducción continuo, con dos períodos de desove anuales en diciembre y marzo. Los parámetros de crecimiento de la función de crecimiento de von Bertalanffy fueron K=0.624 año-1 y L∞=29.3 mm. La mortalidad total (Z fue de Z=2.605 año -1 para los individuos pequeños (entre 2 mm y 5 mm y menor (Z=1.714 año -1 para los individuos grandes (entre 19 mm y 25 mm. La biomasa promedio anual de la población fue =1.22 g de peso seco libre de cenizas m-2 y la producción somática anual Psom/= 1.215 g de peso seco libre de cenizas m-2, lo que corresponde a una tasa de Psom/= 0.988. Aunque se observó un incremento en la densidad poblacional durante noviembre y abril, no hay evidencia de una clara relación entre la densidad poblacional y la ocurrencia del fenómeno "El Niño". Los cambios en la concentración de oxígeno disuelto mostraron una alta correlación con los parámetros del ciclo reproductivo, posiblemente como consecuencia de la influencia de este parámetro en procesos de asimilación y el ciclo de peso corporal. El crecimiento de D. dentifer fue más lento que en otras especies del género, como cabe esperarse para bivalvos tropicales en comparación con los de altas latitudes. El patrón de mortalidad observado sugiere un efecto selectivo de El Niño 97/98 sobre la población, debido a que los individuos pequeños ocupan las partes bajas de la zona intermareal, donde el grado de exposición al agua marina es alto. La producción poblacional e individual fue mayor para los animales de tallas medias en comparación con los animales pequeños aunque estos últimos fueron los más abundantes en la población.Donax dentifer is a dominant member of the sandy beach communities of the Colombian Pacific coast. A population of this bivalve was monthly sampled in Playa Chucheros at the Bay of Málaga, Colombian Pacific, between August 1997 and July 1998, during the "El Niño 1997/1998" phenomenon. Quantitative samples were taken in perpendicular and parallel to the coastal line transects to determine the population density and a length-frequency distribution. Qualitative samples were taken to study the reproduction and monthly length weight relationship. Sea surface temperature, dissolved oxygen, salinity and pH in the water was monthly registered in the sampling station. Additionally, a tagging-recapture experiment was performed to growth estimations. Results indicate a continuous reproduction cycle with two annual spawning seasons in December and March. The growth parameters of the non-oscillating von Bertalanffy growth funetion were K= 0.62 yr-1 and L∞ = 29.3 mm. Mortality (Z was higher (2.65 yr-1 for small individuals (between 2 mm and 5 mm while a lower Z value (1.71 yr-1 were obtained for larger ones (between 19 mm and 25 mm. An annual mean biomass value of B = 1.229 g ash-free dry weight m-2 and an annual somatic production of Psom =1.215 g ash-ftee dry weight m-2 were estimated, which correspond to a Psom / B value of 0.988. Population density increased in November and April, but any population density pattem related with "El Niño" was evident. Low body weight during NovemberDecember seems to show a relation between reproductive cycle in D. dentifer and El Niño 97/98 event. The fluctuation in dissolved oxygen show a high correlation with parameters of the reproductive cycle, which could be relatad to assimilation process and body weight cycle. Growth in D. dentifer in the Colombian Pacific coast was faster than other Donax species, as can be expected for tropical bivalves mollusks in comparison whit high latitude bivalves. The mortality pattern suggest that the population was selectively affected by El Niño 97/98, due to smaller individuals are living in the lowest areas of the beach, where they are exposed to abnormal seawater conditions for a longer time. Individual and population production was higher for medium-size animals than each for small-size ones, which were the most abundant in the population.

Total mercury, methyl mercury, and heavy metal concentrations in Hyeongsan River and its tributaries in Pohang city, South Korea.

Science.gov (United States)

Bailon, Mark Xavier; David, Anneschel Sheehan; Park, Yeongeon; Kim, Eunhee; Hong, Yongseok

2018-04-11

Heavy metal contamination in aquatic systems is a big problem in many areas around the world. In 2016, high mercury concentrations were reported in bivalves (Corbicula leana) and sediments near the confluence of the Hyeongsan River and Chilseong Creek located in Pohang, a steel industrial city in the south-east coast of the Korean peninsula. Given that both the Chilseong and Gumu creeks run through the Pohang industrial complex and ultimately flow to the Hyeongsan River, it is imperative to determine if the industrial effluents have any impact on the mercury contamination in these two streams and the Hyeongsan River. In this work, we investigated the concentration levels of different heavy metals using cold vapor atomic fluorescence spectroscopy and inductively coupled plasma-mass spectroscopy. The metal concentration in the water samples from the Hyeongsan River, Gumu Creek, and Chilseong Creek did not exceed the limits for drinking water quality set by the US EPA and World Health Organization. However, the sediment samples were found to be heavily contaminated by Hg with levels exceeding the toxic effect threshold. Gumu Creek was found to be heavily contaminated. The concentrations of the different heavy metals increased downstream, and the samples collected from the sites in the Hyeongsan River near the Gumu Creek, an open channel for wastewater discharge of companies in the Pohang Industrial Complex, showed higher contamination levels, indicating that the effluents from the industrial complex are a possible source of contamination in the river.

Plant Origin of Green Propolis: Bee Behavior, Plant Anatomy and Chemistry

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Érica Weinstein Teixeira

2005-01-01

Full Text Available Propolis, a honeybee product, has gained popularity as a food and alternative medicine. Its constituents have been shown to exert pharmacological effects, such as anti-microbial, anti-inflammatory and anticancer. Shoot apices of Baccharis dracunculifolia (alecrim plant, Asteraceae have been pointed out as sources of resin for green propolis. The present work aimed (i to observe the collecting behavior of bees, (ii to test the efficacy of histological analysis in studies of propolis botanical origin and (iii to compare the chemistries of alecrim apices, resin masses and green propolis. Bee behavior was observed, and resin and propolis were microscopically analyzed by inclusion in methacrylate. Ethanol extracts of shoot apices, resin and propolis were analyzed by gas chromatography/mass spectroscopy. Bees cut small fragments from alecrim apices, manipulate and place the resulting mass in the corbiculae. Fragments were detected in propolis and identified as alecrim vestiges by detection of alecrim structures. Prenylated and non-prenylated phenylpropanoids, terpenoids and compounds from other classes were identified. Compounds so far unreported for propolis were identified, including anthracene derivatives. Some compounds were found in propolis and resin mass, but not in shoot apices. Differences were detected between male and female apices and, among apices, resin and propolis. Alecrim apices are resin sources for green propolis. Chemical composition of alecrim apices seems to vary independently of season and phenology. Probably, green propolis composition is more complex and unpredictable than previously assumed.

The corbiculate bees arose from New World oil-collecting bees: implications for the origin of pollen baskets.

Science.gov (United States)

Martins, Aline C; Melo, Gabriel A R; Renner, Susanne S

2014-11-01

The economically most important group of bees is the "corbiculates", or pollen basket bees, some 890 species of honeybees (Apis), bumblebees (Bombus), stingless bees (Meliponini), and orchid bees (Euglossini). Molecular studies have indicated that the corbiculates are closest to the New World genera Centris, with 230 species, and Epicharis, with 35, albeit without resolving the precise relationships. Instead of concave baskets, these bees have hairy hind legs on which they transport pollen mixed with floral oil, collected with setae on the anterior and middle legs. We sampled two-thirds of all Epicharis, a third of all Centris, and representatives of the four lineages of corbiculates for four nuclear gene regions, obtaining a well-supported phylogeny that has the corbiculate bees nested inside the Centris/Epicharis clade. Fossil-calibrated molecular clocks, combined with a biogeographic reconstruction incorporating insights from the fossil record, indicate that the corbiculate clade arose in the New World and diverged from Centris 84 (72-95)mya. The ancestral state preceding corbiculae thus was a hairy hind leg, perhaps adapted for oil transport as in Epicharis and Centris bees. Its replacement by glabrous, concave baskets represents a key innovation, allowing efficient transport of plant resins and large pollen/nectar loads and freeing the corbiculate clade from dependence on oil-offering flowers. The transformation could have involved a novel function of Ubx, the gene known to change hairy into smooth pollen baskets in Apis and Bombus. Copyright © 2014 Elsevier Inc. All rights reserved.

FINAL REPORT ON THE AQUATIC MERCURY ASSESSMENT STUDY

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Halverson, N

2008-09-30

showed that determination of representative BAFs for large rivers requires the collection of large numbers of fish and aqueous methylmercury samples over at least one complete seasonal cycle from the entire area and all habitats to be represented by the TMDL. The third study concerned the use of clams as an indicator of the influence of SRS discharges on mercury levels in Savannah River biota. Mercury levels were compared in Asiatic clams (Corbicula fluminea) collected from the discharge plumes and just upstream of the mouths of SRS creeks and two creeks located downstream from the SRS. Asiatic clams were selected for study because their relatively sedentary behavior made them a better indicator of local mercury exposure than mobile organisms.

An example of niche partitioning between Dikerogammarus villosus and other invasive and native gammarids: a field study

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Gerhard MAIER

2005-02-01

Full Text Available The invasive gammarid Dikerogammarus villosus is known to be a strong predator preying voraciously on a wide array of prey organisms including other gammarids. Predation by D. villosus on other gammarids is regarded as a main reason which led to the elimination of native and invasive gammarids in many reaches of European streams. At several sites in the River Danube and in a Rhine tributary, D. villosus was found co-existing with other gammarids. We studied whether predatory D. villosus is spatially segregated from other gammarids which would reduce predatory interactions. Two sites were investigated, one in the Danube (site 1 where D. villosus co-existed with the invasives Echinogammarus ischnus and Dikerogammarus bispinosus and another site in a Rhine tributary (site 2 where D. villosus co-existed with the invasive gammarid Echinogammarus berilloni and two native gammarids, Gammarus pulex and Gammarus roeseli. At site 1, D. villosus was spatially segregated from E. ischnus but not from D. bispinosus; E. ischnus lived at the uppermost shoreline in boulder substrate while Dikerogammarus spp. lived in greater depth in stony to gravelly substrate. At site 2, D. villosus prevailed in greater depth and gravelly to stony substrate where Corbicula molluscs were present while the other species lived in near-shore areas in macrophytes. Our results suggest that co-existence of predatory D. villosus with gammarids is possible by niche partitioning and that high habitat complexity as at site 2 facilitates co-existence. The fact that at site 1 D. bispinosus occupied approximately the same spatial niche than D. villosus cannot be explained at present time.

Pollen harvest features of the Central Amazonian bee Scaptotrigona fulvicutis Moure 1964 (Apidae: Meliponinae, in Brazil Aspectos de coleta de pólen de Scaptotrigona fulvicutis 1964 (Apidae: Meliponinae, abelha da Amazônia Central, Brasil

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Antonio Carlos Marques-Souza

2007-03-01

Full Text Available Over a twelve-month period, pollen loads transported by Scaptotrigona fulvicutis Moure 1964 were collected from the workers corbiculae right after the hive entrance closure in an area of old secondary forest mixed with some exotic fruit trees and ornamentals. Once the pollen grains were identified, their monthly frequency in the samples and grouping by botanical family established that Mimosaceae, Myrtaceae and Sapindaceae were the most frequently visited. The workers harvested the pollen from 97 plant species distributed in 73 genera and 36 families, mostly: Stryphnodendron guianense (Aubl. Benth. in April (57,37% and Schefflera morototoni (Aubl. Frodin in May (54,73%. The harvested pollen types abundance matrix showed that there was little species dissimilarity between the months, which resulted in the formation of two large groups.Durante o período de doze meses, o pólen transportado por Scaptotrigona fulvicutis Moure 1964 foi coletado das corbículas das operárias, logo após o fechamento da entrada das colméias. Feita a identificação polínica dos grãos, sua freqüência mensal nas amostras e o agrupamento por famílias botânicas, constatou-se que as mais visitadas foram: Mimosaceae, Myrtaceae e Sapindaceae. As operárias coletaram o pólen de 97 espécies de plantas distribuídas em 73 gêneros e 36 famílias, sendo as mais freqüentes: Stryphnodendron guianense (Aubl. Benth. em abril (57,37% e Schefflera morototoni (Aubl. Frodin em maio (54,73%. A matriz de abundância dos tipos polínicos coletados mostrou que a dissimilaridade de espécies entre os meses foi pequena o que resultou na formação de dois grandes grupos.

Analysis of economic and energy utilization aspects for waste heat aquaculture

Energy Technology Data Exchange (ETDEWEB)

Olszewski, M.; Wilson, J. V.

1978-01-01

A waste heat aquaculture system using extensive culture techniques to produce fin and shellfish is currently under investigation at the Oak Ridge National Laboratory. The system uses nutrients in waste water streams to grow algae and zooplankton which are fed to fish and clams. A tilapia polyculture association and the freshwater clam Corbicula are the animals cultured in the system. The investigations were performed to determine the economic feasibility of the system and examine energy utilization in the system. A net energy analysis was performed to identify the energy saving potential for the system. This analysis includes all energy costs (both direct and indirect) associated with building and operating the system. The results of the economic study indicated that fish production costs of $0.55/kg ($0.25/lb) were possible. This cost, however, depends upon the fish production rate and food conversion efficiency and could rise to as much as $1.65/kg ($0.75/lb). Clam production costs were found to be in the neighborhood of $0.37/kg of clam meat ($1.24/bushel). The energy utilization study results indicated that, when all energy costs are included, fish from the aquaculture system may require only 35% of the net energy now required for fish products from the ocean. However, the energy requirements also depend on system parameters and could be as large as the energy required for ocean caught products. Clams can be produced in the aquaculture system using only about 25% of the net energy required by traditional means. The results of the analysis indicate that the system appears to be economically feasible. They also indicate that significant energy savings are possible if waste heat aquaculture products replace ocean caught products.

Hox gene expression leads to differential hind leg development between honeybee castes.

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Bomtorin, Ana Durvalina; Barchuk, Angel Roberto; Moda, Livia Maria; Simoes, Zila Luz Paulino

2012-01-01

Beyond the physiological and behavioural, differences in appendage morphology between the workers and queens of Apis mellifera are pre-eminent. The hind legs of workers, which are highly specialized pollinators, deserve special attention. The hind tibia of worker has an expanded bristle-free region used for carrying pollen and propolis, the corbicula. In queens this structure is absent. Although the morphological differences are well characterized, the genetic inputs driving the development of this alternative morphology remain unknown. Leg phenotype determination takes place between the fourth and fifth larval instar and herein we show that the morphogenesis is completed at brown-eyed pupa. Using results from the hybridization of whole genome-based oligonucleotide arrays with RNA samples from hind leg imaginal discs of pre-pupal honeybees of both castes we present a list of 200 differentially expressed genes. Notably, there are castes preferentially expressed cuticular protein genes and members of the P450 family. We also provide results of qPCR analyses determining the developmental transcription profiles of eight selected genes, including abdominal-A, distal-less and ultrabithorax (Ubx), whose roles in leg development have been previously demonstrated in other insect models. Ubx expression in workers hind leg is approximately 25 times higher than in queens. Finally, immunohistochemistry assays show that Ubx localization during hind leg development resembles the bristles localization in the tibia/basitarsus of the adult legs in both castes. Our data strongly indicate that the development of the hind legs diphenism characteristic of this corbiculate species is driven by a set of caste-preferentially expressed genes, such as those encoding cuticular protein genes, P450 and Hox proteins, in response to the naturally different diets offered to honeybees during the larval period.

THE MEDICALLY IMPORTANT MOLLUSCS OF INDONESIA

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Machfudz Djajasasmita

2012-09-01

Full Text Available At present in Indonesia 32 species of non-marine molluscs which belong to IS families have been known to be potentially of medicalor veterinary importance, since they are suspected to be capable in transmitting human and animal diseases. The brackish water family Potamididae comprises of 1 species; whereas the freshwater snails are : Viviparidae (3 sp., Ampullariidae (3 sp., Bythiniidae (1 sp.. Pomatiopsidae (1 sp., Thiaridae (7 sp., Lymnaeidae(l sp. and Planorbidae (5 sp.; freshwater bivalve are: Corbiculidae (4 sp.; land snails are: Subulinidae (2 sp., Achatinidae (1 sp. and Bradybaenidae (1 sp.; land slug: Veronicelidae (2 sp. Philomycidae (1 sp. and Limacidae (1 sp.. All are common species which can be found in the vicinity of human habitation (ponds, rice-field, ditches, gardens etc. The parasitological studies on these molluscs are rather limited, only 9 species have been studied and confirmed to be the intermediate host of parasitic nematodes and nematodes; i.e. Oncomelania hupensis lindoensis, the intermediate host of the blood fluke Schistosoma japonica in Central Sulawesi: Pila suctata, Achatina fulica and Laevicaulis alte from several places in Sumatra, Java, Sulawesi and Flores have been found to be harbouring the larvae of the nematode Angiostrongylus cantonensis, the causative agent of eosinophilic meningoencephalitis; Bellamy a rudipelis, Gyraulus sarasinorum and Corbicula lindoensis were recorded as the intermediate host of the intestinal fluke Echinostoma lindoensis in Central Sulawesi; Lymnaea rubiginosa plays an important role in the life-cycle of the cattle liver fluke Fasciola gigantica and F.hepatica, which may reduce the national meat production; and Digoniostoma truncatum from Bali has been recorded naturally infected with radiae and cercariae of Paramphistoma sp., the causative agent of the fatal paramphistomiasis of cattle. Gyraulus convexiusculus is considered to be the most likely first intermediate host of

The endangered Iris atropurpurea (Iridaceae) in Israel: honey-bees, night-sheltering male bees and female solitary bees as pollinators

Science.gov (United States)

Watts, Stella; Sapir, Yuval; Segal, Bosmat; Dafni, Amots

2013-01-01

Background and Aims The coastal plain of Israel hosts the last few remaining populations of the endemic Iris atropurpurea (Iridaceae), a Red List species of high conservation priority. The flowers offer no nectar reward. Here the role of night-sheltering male solitary bees, honey-bees and female solitary bees as pollinators of I. atropurpurea is documented. Methods Breeding system, floral longevity, stigma receptivity, visitation rates, pollen loads, pollen deposition and removal and fruit- and seed-set were investigated. Key Results The main wild pollinators of this plant are male eucerine bees, and to a lesser extent, but with the potential to transfer pollen, female solitary bees. Honey-bees were found to be frequent diurnal visitors; they removed large quantities of pollen and were as effective as male sheltering bees at pollinating this species. The low density of pollen carried by male solitary bees was attributed to grooming activities, pollen displacement when bees aggregated together in flowers and pollen depletion by honey-bees. In the population free of honey-bee hives, male bees carried significantly more pollen grains on their bodies. Results from pollen analysis and pollen deposited on stigmas suggest that inadequate pollination may be an important factor limiting fruit-set. In the presence of honey-bees, eucerine bees were low removal–low deposition pollinators, whereas honey-bees were high removal–low deposition pollinators, because they removed large amounts into corbiculae and deposited relatively little onto receptive stigmas. Conclusions Even though overall, both bee taxa were equally effective pollinators, we suggest that honey-bees have the potential to reduce the amount of pollen available for plant reproduction, and to reduce the amount of resources available to solitary bee communities. The results of this study have potential implications for the conservation of this highly endangered plant species if hives are permitted inside

Efeito da polinização por abelhas e outros insetos na produção de sementes de cebola Effect of pollination by bees and other insects on the production of onion seeds

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Sidia Witter

2003-12-01

Full Text Available A deficiência de polinização tem sido apontada como uma das causas da baixa produção de sementes na cultura da cebola. O objetivo deste trabalho foi avaliar a relação da presença de abelhas e outros insetos em flores de duas cultivares de cebola, Allium cepa L. (Alliaceae, com a produção de sementes. Foram registradas a diversidade e a freqüência de insetos nas flores de cebola e o efeito polinizador foi testado. O comportamento de Apis mellifera foi observado diretamente nas flores e a fidelidade verificada a partir do pólen nas corbículas. Representantes de Hymenoptera e Diptera foram os visitantes florais mais abundantes. Houve correlação entre a freqüência de A. mellifera com número de umbelas com flores, em ambas cultivares, e de outros insetos em Crioula Alto Vale. A produção de sementes com livre visitação de insetos apresentou acréscimo superior a 20% em relação às parcelas sem insetos e com visita de uma abelha. A. mellifera transportou mais de 70% de pólen de cebola. A presença de A. mellifera é indispensável para a produção comercial de sementes de cebola.Pollination's deficit has been pointed as one of the causes of the low onion seed production. The objective of this work was to evaluate the relationship of the presence of bees and other insects in flowers of two cultivars of onion, Allium cepa L. (Alliaceae, with seed production. The diversity and frequency of insects in flowers of onion was registered and their pollinizing effect was tested. The behavior of Apis mellifera was directly observed in the flowers and the fidelity was testified from the presence of pollen in the corbiculas. Representatives of Hymenoptera and Diptera were the most abundant flower visitors. There was a correlation between frequency of A. mellifera and the number of umbels with flowers in both cultivars and of other insects in Crioula Alto Vale. The production of seeds with free insect visitation had an increase of more

Pollen harvest by Apis mellifera L. (Hymenoptera: Apidae in the Dourados region, Mato Grosso do Sul state (Brazil Pólen coletado por Apis mellifera L. (Hymenoptera: Apidae na região de Dourados, estado de Mato Grosso do Sul (Brasil

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D'Apolito

2010-12-01

Full Text Available We present data on the pollen harvest by Apismellifera L. at a central-western Brazil site not yet studied. Corbiculae pollen loads were collected during one year in front of the hive, acetolysed and slides mounted for optical microscopy. Identification followed comparisons with a local pollen collection. Forty-two pollen types were utilized by the bee; the most important families were Myrtaceae, Asteraceae, Euphorbiaceae, Brassicaceae and Poaceae. The genus/species level ranking of relative importance showed Eucalyptus (19%, Raphanus raphanistrum (13%, Poaceae type 2 (7.5%, Jatropha cf. gossypiifolia (7% and Sapium glandulatum (6.5%. Overall, the majority of pollen types (80% were not abundantly harvested, and a minority (4% reached values of 10%. Given that the study area has cultivated plants and not natural vegetation, we indicate most of the identified species as manageable and point out that weedy vegetation can be an important food source for bees since it frequently occurred in the pollen spectra even within a totally cultivated area.Apresentamos dados sobre a coleta de pólen por Apis mellifera L. em uma localidade no centro-oeste do Brasil, ainda não estudada. Cargas corbiculares de pólen foram coletadas durante um ano em frente ao ninho, acetolisadas e montadas em lâminas para microscopia óptica. A identificação foi feita por comparação com uma coleção de referência local. Quarenta e dois tipos polínicos foram utilizados pelas abelhas; as famílias mais importantes foram Myrtaceae, Asteraceae, Euphorbiaceae, Brassicaceae e Poaceae. O ranqueamento de importância relativa para gênero/espécie mostrou Eucalyptus (19%, Raphanus raphanistrum (13%, Poaceae tipo 2 (7,5%, Jatropha cf. gossypiifolia (7% e Sapium glandulatum (6,5%. No geral, a maioria dos recursos (80% não foi utilizada com abundância, e uma minoria (4% alcançou valores de 10%. Dado que a área de estudo não possui uma vegetação natural, mas cultivares, n

Ocorrência do pólen de Podocarpus sp. (Podocarpaceae nas coletas de Frieseomelitta varia Lepeletier 1836 (Apidae: Meliponinae em uma área de Manaus, AM, Brasil Occurrence of Podocarpus sp. (Podocarpaceae pollen on Frieseomelitta varia Lepeletier 1836 (Apidae: Meliponinae in Manaus, Amazonas, Brazil

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Antonio Carlos Marques-Souza

2010-06-01

Full Text Available Durante o período de doze meses, o pólen transportado por Frieseomelitta varia Lepeletier 1836 foi coletado das corbículas das operárias, logo após o fechamento da entrada das colméias. Feita a identificação polínica dos grãos de pólen e sua frequência mensal nas amostras, constatou-se que as espécies das famílias mais visitadas pela ordem de coleta, foram: Cecropiaceae, Sapotaceae, Myrtaceae e Moraceae. As operárias coletaram o pólen de 79 espécies de plantas distribuídas em 60 gêneros e 37 famílias, sendo as mais frequentes: Cecropia sp. visitada o ano todo com atratividade em janeiro de 82,03%, Morus sp. com atratividade de 37,46% em dezembro; Myrcia amazonica DC. com atratividade em abril de 32,34% e Pouteria macrophylla (A.DC. Eyma em junho com atratividade de 36,54%. Quanto a Podocarpus sp. esse é o primeiro relato da presença do pólen dessa espécie em coletas de meliponíneos, o que não deixa de ser um fato curioso, uma vez que se trata de uma gimnosperma encontrada em áreas específicas da região amazônica e que apresentou atratividade para Frieseomelitta varia Lepeletier 1836 de 4,94% no mês de março.Over a 12 month period, pollen was sampled from the corbiculae of workers of the stingless bee Frieseomelitta varia Lepeletier 1836. Collections were obtained immediately after sealing the hives, located in a forest fragment in the city of Manaus. Pollen was identified and monthly frequency of each type was tallied. The most-visited plant families in decreasing order of frequency were Cecropiaceae, Sapotaceae, Myrtaceae and Moraceae. Identified pollen was harvested from 79 plant species in 60 genera and 37 families. The most frequent species were: Cecropia sp., visited year-round but with highest attractiveness (82% in January; Morus sp., with peak attractiveness (37% in December; Myrcia amazonica DC. with 32% peak attractiveness in April; and Pouteria macrophylla (A.DC. Eyma, with 37% peak attractiveness in