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Sample records for chironomus calligraphus goeldi

  1. Differential sensitivity of Chironomus and human hemoglobin to gamma radiation.

    Science.gov (United States)

    Gaikwad, Pallavi S; Panicker, Lata; Mohole, Madhura; Sawant, Sangeeta; Mukhopadhyaya, Rita; Nath, Bimalendu B

    2016-08-01

    Chironomus ramosus is known to tolerate high doses of gamma radiation exposure. Larvae of this insect possess more than 95% of hemoglobin (Hb) in its circulatory hemolymph. This is a comparative study to see effect of gamma radiation on Hb of Chironomus and humans, two evolutionarily diverse organisms one having extracellular and the other intracellular Hb respectively. Stability and integrity of Chironomus and human Hb to gamma radiation was compared using biophysical techniques like Dynamic Light Scattering (DLS), UV-visible spectroscopy, fluorescence spectrometry and CD spectroscopy after exposure of whole larvae, larval hemolymph, human peripheral blood, purified Chironomus and human Hb. Sequence- and structure-based bioinformatics methods were used to analyze the sequence and structural similarities or differences in the heme pockets of respective Hbs. Resistivity of Chironomus Hb to gamma radiation is remarkably higher than human Hb. Human Hb exhibited loss of heme iron at a relatively low dose of gamma radiation exposure as compared to Chironomus Hb. Unlike human Hb, the heme pocket of Chironomus Hb is rich in aromatic amino acids. Higher hydophobicity around heme pocket confers stability of Chironomus Hb compared to human Hb. Previously reported gamma radiation tolerance of Chironomus can be largely attributed to its evolutionarily ancient form of extracellular Hb as evident from the present study. PMID:27237970

  2. As ciências humanas no Museu Paraense Emílio Goeldi (1988-2003: uma experiência de pesquisa a partir da bibliometria

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    Maria Astrogilda Ribeiro da Silva

    2010-04-01

    Full Text Available O artigo aborda um estudo bibliométrico da produção científica da Coordenação de Ciências Humanas (CCH do Museu Paraense EmílioGoeldi (MPEG. Como procedimentos metodológicos para levantar a produção científica dos pesquisadores da instituição, foram utilizados os critérios de classificação do Ministério da Ciência e Tecnologia (MCT, da Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES, e como indicadores de levantamento dos dados, foram utilizadas informações da Plataforma Lattes, documentos institucionais e bases de dados de produção científica dos pesquisadores do Museu Goeldi. Os resultados apontam para uma predominância de publicações no periódico da instituição, o Boletim do Museu Paraense Emílio Goeldi, Série Antropologia, que reúne artigos das três áreas levantadas nesta pesquisa (Antropologia, Arqueologia e Linguística, seguido por publicações em revistas científicas da área de Arqueologia

  3. Chironomus group classification according to the mapping of polytene chromosomes

    Science.gov (United States)

    Salleh, Syafinaz; Kutty, Ahmad Abas

    2013-11-01

    Chironomus is one of the important genera in Chironomidae family since they are widely diverse and abundance in aquatic ecosystem. Since Chironomus is very diverse, taxonomic work on this genus is very difficult and incomplete. Objective of this study is to form group classification of Chironomus according to the polytene chromosome mapping. The specific characteristics of polytene chromosomes in the salivary gland appeared to be particularly promising for taxonomic diagnosis of chironomid species. Chironomid larvae were collected from pristine sites at Sg. Langat and cultured in laboratory to reach fourth instar stage. The salivary glands were removed from larvae and chromosomes were stained with aceto orcein. Results showed that polytene chromosomes of Chironomus comprise of three long metacentric or submetacentric arms (BF, CD and AE arms) and one short acrocentric (G arm). In regards to nucleolar organizing region (NOR), Balbiani ring (BR), puffings and chromosome rearrangement, a number of four groups of different banding patterns were found. Two groups called as G group A and B have common NOR on arm BF and BR on arm G. However, group A has rearrangement pattern on arm CD and not in group B. This makes group B separated from group A. Another two groups called as groups C and D do not have common NOR on arm BF and also BR on arm G. Groups C and D were separated using arms G and arm AE. At arm G, only group C rearrangement pattern at unit 23c whereas group D was found to have large NOR at arm G and as well as arm AE, only group D has rearrangement pattern at unit 12c. This study indicates that chromosome arrangement could aid in revealing Chironomus diversity.

  4. CHIRONOMUS PLUMOSUS LARVAE - A SUITABLE NUTRIENT FOR FRESHWATER FARMED FISH

    OpenAIRE

    Valentina Rajković; Zdeněk Adámek; Elizabeta Has-Schön; Ivan Bogut; Dalida Galović

    2007-01-01

    Crude protein, fat, water, ash, dry matter and essential amino and fatty acids were analyzed from freshly collected Chironomus plumosus larvae in order to evaluate their suitability as a component for farmed fish diet. The analyses were performed in intact living organisms and in the dry matter. Essential amino acidswere determined by LKB 4101 automatic analyzer, while fatty acids were determined by Chronopack CP 9000 chromatograph with flame ionization detector. Crude protein content was...

  5. Toxicity of cadmium and lead on tropical midge larvae, Chironomus kiiensis Tokunaga and Chironomus javanus Kieffer (Diptera:Chironomidae)

    Institute of Scientific and Technical Information of China (English)

    Warrin Ebau; Che Salmah Md Rawi; Zubir Din; Salman Abdo Al-Shami

    2012-01-01

    Objective: To investigate the acute toxicity of cadmium and lead on larvae of two tropical Chironomid species, Chironomus kiiensis (C. kiiensis) Tokunaga and Chironomus javanus (C. javanus) Kieffer. Methods: Different larval instars (first-fourth) were exposed using a static non-replacement testing procedures to various concentrations of cadmium and lead. Results:In general, younger larvae (first and second instars) of both species were more sensitive to both metals than older larvae (third and forth instars). The toxic effects of the metals on C. kiiensis and C. javanus were influenced by the age of the larvae (first to fourth instars), types of metals (cadmium or lead) and duration of larval exposure (24, 48, 72 and 96 h) to the metals. Conclusions: Cadmium was more toxic to the chironomids than lead and C. javanus was significantly more sensitive to both metals than C. kiiensis (P<0.05).

  6. The basic repeat unit of a Chironomus Balbiani ring gene.

    OpenAIRE

    Bäumlein, H; Wobus, U; Gerbi, S A; Kafatos, F C

    1982-01-01

    A clone derived from the Balbiani ring b (BRb) gene of Chironomus thummi has been used to study the internal organization of that gene. Much of the gene consists of approximately 80 copies of a ca. 300 bp repeat unit, which are tandemly organized. The BRb clone contains a major part of that unit (242 bp). Sequence analysis shows that approximately 60% of the unit corresponds to short, tandemly organized subsequences, which encode peptides 8 to 11 residues long. In turn, each subsequence consi...

  7. Genotoxic effect of Phenanthrene on Chironomus sancticaroli (Diptera: Chironomidae

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    Gisele dos Santos Morais

    2014-08-01

    Full Text Available Phenanthrene, a Polycyclic Aromatic Hydrocarbon, remains adsorbed to sedimentary particles in aquatic environments. It affects mainly benthic organisms, and is considered potentially genotoxic. In ecotoxicology, species of Chironomus Meigen, 1803 are widely known as bioindicators of the effects of chemicals on aquatic organisms. This study investigates the effects of phenanthrene on the size of the head capsule of Chironomus sancticaroli Strixino & Strixino, 1981 larvae after chronic (eight days exposure, and DNA damage after acute (96 hours and chronic exposure (eight days, under laboratory conditions. DNA damage, evaluated using the alkaline comet assay, detected effects for both exposure periods, indicating that phenanthrene is toxic for C. sancticaroli. For the acute exposure, we analyzed five concentrations of phenanthrene, between 0.16 mg.l-1 and 1.60 mg.l-1, detecting significant differences (Kruskall-Wallis test with p < 0.05 in the degree of DNA damage in all groups. These effects were not dose-dependent. For the chronic exposure, two concentrations (0.16 mg.l-1, 0.83 mg.l-1 were analyzed, and DNA damage was observed in both. Again, the effects were not dose-dependent. This indicates that phenanthrene is genotoxic to larvae of C. sancticaroli even at low concentrations. The size of the head capsule was evaluated after chronic exposure to concentrations of 0.16 mg.l-1 and 0.83 mg.l-1. Significant differences (ANOVA test with p < 0.05 were detected in the two concentrations, and a reduction in the size of the larval head capsule was observed. This suggests that phenanthrene causes delay in larval development. These results indicate that phenanthrene affects the development of and causes DNA damage in C. sancticaroli larvae. Therefore, we suggest that C. sancticaroli can be used as a biological indicator for environmental contamination with phenanthrene.

  8. Chromosomal organization of the ribosomal RNA genes in the genus Chironomus (Diptera, Chironomidae

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    Larisa Gunderina

    2015-05-01

    Full Text Available Chromosomal localization of ribosomal RNA coding genes has been studied by using FISH (fluorescence in situ hybridization in 21 species from the genus Chironomus Meigen, 1803. Analysis of the data has shown intra- and interspecific variation in number and location of 5.8S rDNA hybridization sites in 17 species from the subgenus Chironomus and 4 species from the subgenus Camptochironomus Kieffer, 1914. In the majority of studied species the location of rDNA sites coincided with the sites where active NORs (nucleolus organizer regions were found. The number of hybridization sites in karyotypes of studied chironomids varied from 1 to 6. More than half of the species possessed only one NOR (12 out of 21. Two rDNA hybridization sites were found in karyotypes of five species, three – in two species, and five and six sites – in one species each. NORs were found in all chromosomal arms of species from the subgenus Chironomus with one of them always located on arm G. On the other hand, no hybridization sites were found on arm G in four studied species from the subgenus Camptochironomus. Two species from the subgenus Chironomus – Ch. balatonicus Devai, Wuelker & Scholl, 1983 and Ch. “annularius” sensu Strenzke, 1959 – showed intraspecific variability in the number of hybridization signals. Possible mechanisms of origin of variability in number and location of rRNA genes in the karyotypes of species from the genus Chironomus are discussed.

  9. CHIRONOMUS PLUMOSUS LARVAE - A SUITABLE NUTRIENT FOR FRESHWATER FARMED FISH

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    I. Bogut

    2007-06-01

    Full Text Available Crude protein, fat, water, ash, dry matter and essential amino and fatty acids were analyzed from freshly collected Chironomus plumosus larvae in order to evaluate their suitability as a component for farmed fish diet. The analyses were performed in intact living organisms and in the dry matter. Essential amino acids were determined by LKB 4101 automatic analyzer, while fatty acids were determined by Chronopack CP 9000 chromatograph with flame ionization detector. Crude protein content was 7.6% and 55.7% in fresh larvae and dry matter, respectively, being a value adequate for growth needs of all freshwater fish sorts and categories. Most essential amino acids in fresh larvae and dry matter are present in quantities adequate for feeding majority of omnivorous and carnivorous freshwater fish species. Crude fat content was 1.3% and 9.7% in fresh larvae and dry matter, respectively, being energetically sufficient for all warm-water living fish. The crude fat contains 26.12% saturated, 30.42% monounsaturated and 34.03% polyunsaturated fatty acids (PUFA. Among the highly unsaturated fatty acids (HUFA, the most abundant is linolenic (7.21%, followed by eicosapentanoic (4.36%, docosahexaenoic (2.49% and docosapentaenoic (1.16% acid. The measured quantity of ω-3 and ω-6 fatty acids (essential for omnivorous fish, as well as ω-6 to ω-3 fatty acid ratio (0.81, completely meets nutritional requirements of carp and tench.

  10. Method refinements for the midge life-cycle, Chironomus dilutus test

    Science.gov (United States)

    Larval stages of non-biting midges can be found in almost any freshwater ecosystem, and one of the commonly tested midges is Chironomus dilutus (Chironomidae, Diptera) which is used for toxicity testing and ecological risk assessment of freshwater contaminants. USEPA, ASTM, Envir...

  11. Chironomus larvae (Chironomidae: Diptera) as water quality indicators along an environmental gradient in a neotropical urban stream

    OpenAIRE

    Nadja Gomes Machado; Danielle Christine Stenner Nassarden; Francyele dos Santos; Isabelle Christina Gonçalves Boaventura; Gregory Perrier; Fernanda Silveira Carvalho de Souza; Eucarlos de Lima Martins; Marcelo Sacardi Biudes

    2015-01-01

    Anthropogenic interference in urban lotic systems is a factor affecting the biota of waterbodies. Aquatic macro invertebrates are an important food source for fish and are valuable indicators of water quality. The objective of this work was to study Chironomus larvae (Chironomidae: Diptera) distribution along an environmental gradient in Barbado Stream, Cuiabá, MT, Brazil. No individual Chironomus was found in the springs of Barbado Stream, which may indicate preservation of the area. During ...

  12. The protective nature of Chironomus luridus larval tubes against copper sulfate

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    M. Halpern

    2002-05-01

    Full Text Available The objective of this study was to determine whether the tubes in which Chironomus larvae dwell protect them against chemical toxicants. A laboratory culture of an Israeli benthic midge, Chironomus luridus, was exposed to copper sulfate. Two conditions were tested in bioassay experiments: larvae within silt tubes and larvae without tubes. The non toxic, anionic, fluorescent dye, fluorescein, was used to examine the effect of sub-lethal copper sulfate concentrations on the permeability of cuticular, gill and gut epithelia of the chironomids. Increased cell permeability, which is the cause of cell damage, was reflected by an increase in fluorescence intensity. Following exposure to copper sulfate, higher fluorescence was found in different body compartments: midgut, hindgut, tracheal gills, fat body and muscles, and the Malpighian tubules. The effect was significantly higher in tube-free larvae when compared to silt tube dwelling larvae. We conclude that in addition to its other functions in feeding, respiration, and anti-predation shelter, the Chironomus luridus tube protects its inhabitant from toxins such as copper sulfate.

  13. Decaying cyanobacteria decrease N2O emissions related to diversity of intestinal denitrifiers of Chironomus plumosus

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    Xu Sun

    2014-10-01

    Full Text Available Nitrous oxide (N2O emission of fresh invertebrates has too long been neglected in eutrophic lakes, although the sediments these animals inhabit are presumably hot spots of N2O emission. Thus, the experiment in this research was designed to gain insight into the influence of cyanobacterial degradation on the N2O emission by fresh water invertebrates (Chironomus plumosus. The presence of decaying cyanobacteria in Lake Taihu decreased the N2O emission rate of Chironomus plumosus larvae from the larvae body by almost 400% for the larvae as a whole. The N2O emission rate decreased by 350% based on readings from studies of their gut, which was mostly due to stimulation of intestinal complete denitrification. The quantitative PCR results showed that intestinal gene abundance of nirK, nosZ (encoding the copper nitrite reductase and N2O reductase, respectively were significantly increased with the presence of decaying cyanobacteria. In contrast nirS (encoding the cytochrome cd1 heme nitrite reductase and the total bacteria decreased. In the gut of Chironomus plumosus, the diversity and richness of nosZ and nirK were lower with the cyanobacteria. Phylogenetic analysis of the intestinal function genes (nosZ and nirK showed that the nosZ- and nirK-type denitrifying bacterial sequences were related to different phylotypes. Hence, additional cyanobacteria increased the abundance, but decreased the richness and diversity of intestinal nitrate-reducing bacteria, probably by providing more carbon source in the gut. The data obtained in this study elucidates that the decaying cyanobacteria decreased the emissions of N2O by the aquatic invertebrates in freshwater sediment and could serve as a valuable resource for nitrogen removal affecting greenhouse gas emissions.

  14. Population variability in Chironomus (Camptochironomus) species (Diptera, Nematocera) with a Holarctic distribution : evidence of mitochondrial gene flow

    NARCIS (Netherlands)

    Martin, J; Guryev, V; Blinov, A

    2002-01-01

    Phylogenetic analysis of DNA sequences from mitochondrial (mt) genes (Cytochrome b and Cytochrome oxidase I) and one nuclear gene (globin 2b) was used for the investigation of Nearctic and Palearctic populations representing four Chironomus species of the subgenus Camptochironomus, namely C. biwapri

  15. Sediment microbes and biofilms increase the bioavailability of chlorpyrifos in Chironomus riparius (Chironomidae, Diptera).

    Science.gov (United States)

    Widenfalk, Anneli; Lundqvist, Anna; Goedkoop, Willem

    2008-10-01

    In a microcosm study, the importance of different sources of organic matter (humic acids, sterile sediment, sediment, and a microbial extract) for the bioavailability of the hydrophobic pesticide chlorpyrifos to Chironomus riparius larvae was quantified. In the last two treatments biofilms were allowed to grow before (14)C-chlorpyrifos addition. Chlorpyrifos accumulation was quantified after 25 h of exposure and after 21 h of depuration. Larval accumulation was twice as high in the microbial extract treatment (447+/-79 microg/kg ww larvae) and 1.7 times higher in the sediment treatment (371+/-33 microg/kg). After depuration, chlorpyrifos accumulation in larval tissue showed even higher differences; 3.1 times higher tissue concentrations in the microbial extract treatment (218+/-21 microg/kg) and 2.2 times higher in the sediment treatment (156+/-35 microg/kg). In contrast, chlorpyrifos accumulation in the humic acid and sterile sediment did not differ from that in controls. These results show that living microbes and biofilms, by creating a microenvironment and providing food for larvae, markedly increase the bioavailability of chlorpyrifos to Chironomus riparius.

  16. Refining methods for conducting long-term sediment and water toxicity tests with Chironomus dilutus: Formation of a midge chronic testing work group

    Science.gov (United States)

    Standard methods have been established by USEPA, ASTM International, Environment Canada and Organization for Economic Cooperation and Development for conducting sediment toxicity tests with various species of midges including Chironomus dilutus. Short-term 10-day exposures are ty...

  17. Effects of sediment contamination by artisanal gold mining on Chironomus riparius in Mabubi River, Tanzania

    Science.gov (United States)

    Chibunda, R. T.; Pereka, A. E.; Tungaraza, C.

    The contamination of sediments by mercury from in artisanal gold mining has been only assessed through bulk chemical analysis and subsequent comparison with reference values from uncontaminated areas. However, measurement of contaminant levels alone has a limited ability to predict adverse effects on living resources. This study investigated the possible effects of contamination of sediments in Mabubi River by mercury drained from Mugusu artisanal gold mine on the survival, growth and emergency of the benthic midge Chironomus riparius. Sediments collected downstream from the Mugusu Mine impaired growth and delayed emergence of the midges but did not impair survival. Mean dry body weight of larvae from sediments collected 3 km down stream (1012 μg) was significantly lower than those from the control sediment ( p River downstream of the Mugusu mine adversely affect C. riparius and probably other fauna and as such present a considerable local environmental risk.

  18. Apedilum griseistriatum comb. nov., placement of Chironomus (Polypedilum griseistriatum (Diptera, Chironomidae

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    Mariano Donato

    2015-03-01

    Full Text Available The study of the type material of Chironomus (Polypedilum griseistriatum Edwards, 1931 described from Patagonia lead us to formally transfer the species to Apedilum Townes, 1945 as a new combination, and a reared specimen allows us to describe its pupa. Based on several larvae belonging to Apedilum collected in the proximity of the localities in which the adults and pupae were found, we tentatively describe the larval stage. Subfossil larval head capsules of the same species were found in Laguna Stibnite at 46°S in Chile dated to about 2,500 years ago and in Puerto Blest, Lago Nahuel Huapi at 41°S in Argentina dated about 2,000 years ago. We discuss the habitat of the species based on both modern and subfossil material. Identification keys to male adult, pupae and fourth instar larvae are also provided.

  19. Chironomus larvae (Chironomidae: Diptera as water quality indicators along an environmental gradient in a neotropical urban stream

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    Nadja Gomes Machado

    2015-04-01

    Full Text Available Anthropogenic interference in urban lotic systems is a factor affecting the biota of waterbodies. Aquatic macro invertebrates are an important food source for fish and are valuable indicators of water quality. The objective of this work was to study Chironomus larvae (Chironomidae: Diptera distribution along an environmental gradient in Barbado Stream, Cuiabá, MT, Brazil. No individual Chironomus was found in the springs of Barbado Stream, which may indicate preservation of the area. During the study period, we found 40.3 and 94.4 individuals/m2 at points 3 and 4 (low course, respectively. There is eutrophication in these sites due to domestic sewage discharges, indicating low quality water. The Barbado Stream needs restoration projects that include an awareness of the residents of their neighborhood’s environmental importance, and investments in the sanitation sector to prioritize the collection and treatment of wastewater and solid waste collection.

  20. Assessment of potential biomarkers, metallothionein and vitellogenin mRNA expressions in various chemically exposed benthic Chironomus riparius larvae

    Science.gov (United States)

    Park, Kiyun; Kwak, Inn-Sil

    2012-12-01

    The objective of this study was conducted to identify the possibility of using Chironomus metallothionein (MT) and vitellogenin (VTG) as biomarkers of stress caused by endocrinedisrupting chemicals (EDCs), heavy metals, herbicides and veterinary antibiotics. We characterized the MT and VTG cDNA in Chironomus riparius and evaluated their mRNA expression profiles following exposure to different environmental pollutants. The gene expression analysis showed that the MT mRNA levels increased significantly after long-term exposure to cadmium (Cd), copper (Cu), Lead (Pb), di(2-ethylhexyl) phthalate (DEHP), and 2,4-dichlorophenoxyacetic acid (2,4-D). Moreover, the VTG mRNA expression increased significantly in C. riparius larvae exposed to BPA, NP, DEHP, Cd, 2,4-D and fenbendazole. Evaluation of the long-term effects of environmental pollutants revealed up regulation of Chironomus MT mRNA in response to DEHP exposure among EDCs, and the level of the VTG mRNA was increased significantly following treatment with Cd and herbicide 2,4-D at all concentrations in a dose-dependent manner. These results indicate that VTG could be used as a potential biomarker of herbicide and Cd as well as EDCs, while MT was a potential biomarker of heavy metals such as Cd, Cu, and Pb in aquatic environments.

  1. Patterns of Fluctuating Asymmetry and Shape Variation in Chironomus riparius (Diptera, Chironomidae) Exposed to Nonylphenol or Lead

    Science.gov (United States)

    Arambourou, Hélène; Beisel, Jean-Nicolas; Branchu, Philippe; Debat, Vincent

    2012-01-01

    Deformities and fluctuating asymmetry in chironomid larvae have been proposed as sensitive indicators of biological stress and are commonly used to assess the ecological impact of human activities. In particular, they have been associated in Chironomus riparius, the most commonly used species, with heavy metal and pesticide river pollution. In this study, the effect of lead and 4-nonylphenol on mouthpart morphological variation of Chironomus riparius larvae was investigated by traditional and geometric morphometrics. For this purpose, first to fourth instar larvae were exposed to sediment spiked with lead (from 3.0 to 456.9 mg/kg dry weight) or 4-NP (from 0.1 to 198.8 mg/kg dry weight). Mentum phenotypic response to pollutants was assessed by four parameters: (1) the frequency of deformities, (2) fluctuating asymmetry of mentum length, (3) fluctuating asymmetry of mentum shape and (4) the mentum mean shape changes. Despite the bioaccumulation of pollutants in the chironomid’s body, no significant differences between control and stressed groups were found for mouthpart deformities and fluctuating asymmetry of mentum length. Slight effects on mentum shape fluctuating asymmetry were observed for two stressed groups. Significant mean shape changes, consisting of tooth size increase and tooth closing, were detected for lead and 4-NP exposure respectively. Those variations, however, were negligible in comparison to mentum shape changes due to genetic effects. These results suggest that the use of mentum variation as an indicator of toxic stress in Chironomus riparius should be considered cautiously. PMID:23133660

  2. Genes involved in cysteine metabolism of Chironomus tepperi are regulated differently by copper and by cadmium.

    Science.gov (United States)

    Jeppe, Katherine J; Carew, Melissa E; Long, Sara M; Lee, Siu F; Pettigrove, Vincent; Hoffmann, Ary A

    2014-05-01

    Freshwater invertebrates are often exposed to metal contamination, and changes in gene expression patterns can help understand mechanisms underlying toxicity and act as pollutant-specific biomarkers. In this study the expressions of genes involved in cysteine metabolism are characterized in the midge Chironomus tepperi during exposures to sublethal concentrations of cadmium and copper. These metals altered gene expression of the cysteine metabolism differently. Both metals decreased S-adenosylhomocysteine hydrolase expression and did not change the expression of S-adenosylmethionine synthetase. Cadmium exposure likely increased cystathionine production by up-regulating cystathionine-β-synthase (CβS) expression, while maintaining control level cysteine production via cystathionine-γ-lyase (CγL) expression. Conversely, copper down-regulated CβS expression and up-regulated CγL expression, which in turn could diminish cystathionine to favor cysteine production. Both metals up-regulated glutathione related expression (γ-glutamylcysteine synthase and glutathione synthetase). Only cadmium up-regulated metallothionein expression and glutathione S-transferase d1 expression was up-regulated only by copper exposure. These different transcription responses of genes involved in cysteine metabolism in C. tepperi point to metal-specific detoxification pathways and suggest that the transsulfuration pathway could provide biomarkers for identifying specific metals.

  3. Ecotoxicological assessment of grey water treatment systems with Daphnia magna and Chironomus riparius.

    Science.gov (United States)

    Hernández Leal, L; Soeter, A M; Kools, S A E; Kraak, M H S; Parsons, J R; Temmink, H; Zeeman, G; Buisman, C J N

    2012-03-15

    In order to meet environmental quality criteria, grey water was treated in four different ways: 1) aerobic 2) anaerobic+aerobic 3) aerobic+activated carbon 4) aerobic+ozone. Since each treatment has its own specific advantages and disadvantages, the aim of this study was to compare the ecotoxicity of differently treated grey water using Chironomus riparius (96 h test) and Daphnia magna (48 h and 21d test) as test organisms. Grey water exhibited acute toxicity to both test organisms. The aerobic and combined anaerobic+aerobic treatment eliminated mortality in the acute tests, but growth of C. riparius was still affected by these two effluents. Post-treatment by ozone and activated carbon completely removed the acute toxicity from grey water. In the chronic toxicity test the combined anaerobic+aerobic treatment strongly affected D. magna population growth rate (47%), while the aerobic treatment had a small (9%) but significant effect. Hence, aerobic treatment is the best option for biological treatment of grey water, removing most of the toxic effects of grey water. If advanced treatment is required, the treatment with either ozone or GAC were shown to be very effective in complete removal of toxicity from grey water.

  4. Adaptive response of Chironomus riparius populations exposed to uranium contaminated sediments during consecutive generations

    International Nuclear Information System (INIS)

    The intensity of selection on populations caused by polluted environment often exceeds which is caused by an unpolluted environment. Therefore, micro evolution can occur in response to this anthropic-directional force over a short period. In this context, this thesis focused on studying phenotypic changes in Chironomus riparius populations exposed during several consecutive generations to uranium-contaminated sediments. In laboratory-controlled conditions experiments were conducted with same origin populations exposed to a range of uranium concentration inducing toxic effects. Over eight-generations of exposure, life-history traits measures revealed micro evolution in exposed populations, including increase of adult reproductive success. Other experiments (acute toxicity test, common garden experiment) performed in parallel enabled to link these micro evolution with a tolerance induction, as a consequence of genetic adaptation. Nonetheless this adaptation also induced cost in terms of fitness and genetic diversity for pre-exposed populations. These results lead to the hypothesis of a selection by uranium that acted sequentially on populations. They also underline the need to better-understand the adaptive mechanisms to better assess the ecological consequences of chronic exposure of populations to a pollutant. (author)

  5. Determination of larval instars in Chironomus sancticaroli (Diptera: Chironomidae using novel head capsule structures

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    Vinicius S. Richardi

    2013-04-01

    Full Text Available Determining the age composition of a population is important when conducting ecological, taxonomic and environmental assessments. Morphometric measurements of the head capsule, especially the length and width, are widely used in the identification of insect instars, but alternative ways for determining the age of insects can expand the options for the analysis of field and laboratory populations. This study evaluated the morphometry of the antennae, mandibles, mentum and ventromental plates to discriminate among the four larval instars of Chironomus sancticaroli Strixino & Strixino, 1981. The larvae were reared in the laboratory under constant temperature (25°C and photoperiod of 12/12 hours for 19 days, with a supply of food. Fifteen larvae were removed randomly every day, cleared in KOH, and slide-mounted, and had the antennae, mandibles, mentum and ventromental plates measured. The dimensions of the four structures studied allowed us to statistically distinguish each of the four larval instars. The data fit an exponential equation according to the Brooks-Dyar rule, which allows an estimate of the larval instar of specimens collected in the field, even when development takes place under different conditions. The duration of each instar was also obtained from our data, and showed an overlap of instars during development.

  6. Cadmium transport by the gut and Malpighian tubules of Chironomus riparius

    Energy Technology Data Exchange (ETDEWEB)

    Leonard, Erin M., E-mail: leonarem@mcmaster.ca [Department of Biology, McMaster University, Hamilton, ON, L8S 4K1 (Canada); Pierce, Laura M. [Department of Biology, McMaster University, Hamilton, ON, L8S 4K1 (Canada); Gillis, Patricia L. [Aquatic Ecosystem Protection Research Division, Environment Canada, Burlington, ON, L7R 4A6 (Canada); Wood, Chris M.; O' Donnell, Michael J. [Department of Biology, McMaster University, Hamilton, ON, L8S 4K1 (Canada)

    2009-05-05

    Many aquatic insects are very insensitive to cadmium in short-term laboratory studies. LC50 values for larvae of the midge Chironomus riparius are over 25,000 times the Criterion Maximum Concentration in the United States Environmental Protection Agency (U.S. EPA (2000)) species sensitivity distribution (SSD). Excretion or sequestration of cadmium may contribute to insensitivity and we have therefore examined cadmium transport by isolated guts and renal tissues of C. riparius larvae. Regional differences of Cd transport along the gut were identified using a Cd{sup 2+}-selective microelectrode in conjunction with the Scanning Ion-Selective Electrode Technique (SIET). Cd is transported into the anterior midgut (AMG) cells from the lumen and out of the cells into the hemolymph. The transport of Cd from the gut lumen to the hemolymph exposes other tissues such as the nervous system and muscles to Cd. The gut segments which remove Cd from the hemolymph at the highest rate are the posterior midgut (PMG) and the ileum. In addition, assays using an isolated Malpighian (renal) tubule preparation have shown that the Malpighian tubules (MT) both sequester and secrete Cd. For larvae bathed in 10 {mu}mol l{sup -1} Cd, the tubules can secrete the entire hemolymph burden of Cd in {approx}15 h.

  7. Experimental evidence for cadmium uptake via calcium channels in the aquatic insect Chironomus staegeri

    International Nuclear Information System (INIS)

    We used the chironomid Chironomus staegeri to investigate the mechanism of cadmium (Cd) uptake in aquatic insects. We exposed C. staegeri larvae to a low nominal Cd concentration (50 nM) for 3 days and measured the effects of calcium (Ca) concentration (0.1-10 mM Ca) as well as the Ca channel blockers lanthanum and verapamil on Cd accumulation. When Ca2+ concentrations were increased above a control (0.1 mM Ca2+) to 1-10 mM, Cd accumulation by larvae was inhibited by from 46 to 88%, respectively. A simple theoretical model of Cd-Ca competition for uptake sites fitted our observations well. Cadmium accumulation was significantly inhibited in a concentration-dependent manner by both La (73% at 10 μM and 92% at 100 μM) and verapamil (59% at 100 μM and 85% at 300 μM). Our findings represent strong evidence that Cd entry into these insects occurs through Ca channels. (Copyright (c) 1999 Elsevier Science B.V., Amsterdam. All rights reserved.)

  8. Ecotoxicological multilevel-evaluation of the effects of fenbendazole exposure to Chironomus riparius larvae.

    Science.gov (United States)

    Park, Kiyun; Bang, Hyun Woo; Park, Jungan; Kwak, Inn-Sil

    2009-10-01

    Veterinary antibiotics may find their way into the aquatic environment through direct or indirect pathways due to their widespread use. Fenbendazole is a benzimidazole anthelmintic that is widely used in veterinary medicine. To evaluate the potential ecological risk of fenbendazole, we examined the molecular and biochemical responses of biomarker genes such as heat shock proteins (HSPs), cytochrome P450 (CYP450), glutathione S-transferases (GSTs) and hemoglobins (Hbs) in Chironomus riparius for long periods. The expression of HSP70, HSP40, HSP90 and CYP450 in C. riparius increased significantly after exposure to all concentrations of fenbendazole evaluated, while the levels of GST and HbA only increased in C. riparius exposed to relatively high concentrations of fenbendazole (30 microg L(-1)). HbB expression did not differ significantly between the control and treatment groups. Exposure to 30 microg L(-1) fenbendazole had significant effects on the survival, growth, sex balance of emergent adults and development of mouthpart deformity in C. riparius. These results should constitute an important contribution to the understanding of the toxicology of fenbendazole in C. riparius. Moreover, the responses of the biomarker genes also provide valuable information that will aid in understanding the effects of fenbendazole in aquatic ecosystems.

  9. Ecotoxicological assessment of grey water treatment systems with Daphnia magna and Chironomus riparius.

    Science.gov (United States)

    Hernández Leal, L; Soeter, A M; Kools, S A E; Kraak, M H S; Parsons, J R; Temmink, H; Zeeman, G; Buisman, C J N

    2012-03-15

    In order to meet environmental quality criteria, grey water was treated in four different ways: 1) aerobic 2) anaerobic+aerobic 3) aerobic+activated carbon 4) aerobic+ozone. Since each treatment has its own specific advantages and disadvantages, the aim of this study was to compare the ecotoxicity of differently treated grey water using Chironomus riparius (96 h test) and Daphnia magna (48 h and 21d test) as test organisms. Grey water exhibited acute toxicity to both test organisms. The aerobic and combined anaerobic+aerobic treatment eliminated mortality in the acute tests, but growth of C. riparius was still affected by these two effluents. Post-treatment by ozone and activated carbon completely removed the acute toxicity from grey water. In the chronic toxicity test the combined anaerobic+aerobic treatment strongly affected D. magna population growth rate (47%), while the aerobic treatment had a small (9%) but significant effect. Hence, aerobic treatment is the best option for biological treatment of grey water, removing most of the toxic effects of grey water. If advanced treatment is required, the treatment with either ozone or GAC were shown to be very effective in complete removal of toxicity from grey water. PMID:22197265

  10. Growth of Chironomus dilutus larvae exposed to ozone-treated and untreated oil sands process water

    International Nuclear Information System (INIS)

    Oil sand processing operations require large quantities of freshwater and produce large volumes of oil sands process water (OSPW) which must be stored on-site. This presentation reviewed various treatment methods for remediating OSPW in order to eliminate downstream toxicity. Naphthenic acids are the most important target fractions for treatment because they are primarily responsible for the acute toxicity of OSPW. Although ozonation has shown promise for reducing OSPW toxicity, the effects of ozonation on aquatic invertebrates remain unknown. This study investigated the effects of exposure to untreated and ozonated OSPW in Chironomus dilutus larvae. OSPW was treated with either a 50 or 80 mg O3/L dose of ozonation. The effects of ozonation levels on C. dilutus survival and growth were examined. The study showed that after a 10-day exposure, there were pronounced effects on survival of larvae exposed to ozone-treated or untreated OSPW. Larvae exposed to OSPW were 64-77 percent smaller than their respective controls, but the mean wet mass of organisms exposed to 50 mg O3/L ozonated OSPW was not much different from that of the controls. Larvae exposed to 80 mg O3/L ozone-treated OSPW were 40 percent smaller than the freshwater controls, and the mean wet mass was also much larger than the untreated OSPW. It was concluded that the toxicity of OSPW to benthic invertebrates may be reduced by ozone treatment.

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

    Science.gov (United States)

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

    2011-07-01

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

  12. Hypoxia and anoxia effects on alcohol dehydrogenase activity and hemoglobin content in Chironomus riparius Meigen, 1804

    Directory of Open Access Journals (Sweden)

    Valentina Grazioli

    2016-02-01

    Full Text Available The metabolic effects of low oxygen content on alcohol-dehydrogenase (ADH activity and hemoglobin (Hb concentration were investigated in IV-instar larvae of Chironomus riparius (Diptera: Chironomidae from an Italian stream. Two series of short-term (48 h experiments were carried out: exposure to (1 progressive hypoxia (95 to 5% of oxygen saturation and (2 anoxia (at <5% of oxygen saturation. In (1, Hb amount increased with increasing oxygen depletion up to a critical value of oxygenation (about 70% of oxygen saturation. Below this percentage, the Hb amount declined to values comparable with those present in the control. The respiration rate (R remained almost constant at oxygen saturation >50% and decreased significantly only after 48 h of treatment (= <5% of oxygen saturation reaching values <100 mmolO2 gAFDW-1 h-1. ADH activity showed two phases of growth, within the first 14 h and over 18 h of exposure. Overall, we inferred that i Hb might function as short-term oxygen storage, enabling animals to delay the on-set of anaerobiosis; and ii alcoholic fermentation co-occurs for a short time with aerobic respiration, becoming the prevalent metabolic pathway below 5% of oxygen saturation (<1 mg L-1. These considerations were supported also by results from anoxia exposure (2. In such condition, larvae were visibly stressed, becoming immobile after few minutes of incubation, and ADH reached higher values than in the hypoxia treatment (2.03±0.15 UADH mg prot-1. Overall, this study showed a shift from aerobic to anaerobic activity in C. riparius larvae exposed to poorly oxygenated water with an associated alteration of ADH activity and the Hb amount. Such metabolites might be valid candidate biomarkers for the environmental monitoring of running waters.

  13. A Determination of Metallothionein in Larvae of Freshwater Midges (Chironomus riparius Using Brdicka Reaction

    Directory of Open Access Journals (Sweden)

    Rene Kizek

    2008-07-01

    Full Text Available Among wide spectrum of biomolecules induced by various stress factors low molecular mass protein called metallothionein (MT is suitable for assessment of the heavy metal environmental pollution. The aim of this work was to determine the metallothionein and total thiols content in larvae of freshwater midges (Chironomus riparius sampled from laboratory exposure to cadmium(II ions and from field studies using differential pulse voltammetry Brdicka reaction. Unique electrochemical instrument, stationary electrochemical analyser Autolab coupled with autosampler, was utilized for the analysis of the samples. The detection limit for MT was evaluated as 5 nM. The larvae exposed to two doses (50 ng/g or 50 μg/g of cadmium(II ions for fifteen days under laboratory controlled conditions were at the end of the exposure killed, homogenized and analysed. MT content in control samples was 1.2 μM, in larvae exposed to 50 ng Cd/g it was 2.0 μM and in larvae exposed to 50 μg Cd/g 2.9 μM. Moreover at field study chironomid larvae as well as sediment samples have been collected from eight field sites with different levels of pollution by heavy. The metals content (chromium, nickel, copper, zinc, arsenic, molybdenum, cadmium, tin and lead in the sediment and or MT content in the chironomid larvae were determined by inductively coupled plasma mass spectrometry or Brdicka reaction, respectively.

  14. Hazard evaluation of ten organophosphorous insecticides against the midge, Chironomus riparius via QSAR

    Science.gov (United States)

    Landrum, Peter F.; Fisher, Susan W.; Hwang, Haejo; Hickey, James P.

    1999-01-01

    Toxicities of ten organophosphorus (OP) insecticides were measured against midge larvae (Chironomus riparius) under varying temperature (11, 18, and 25°C) and pH (6, 7, and 8) conditions and with and without sediment. Toxicity usually increased with increasing temperature and was greater in the absence of sediment. No trend was found with varying pH. A series of unidimensional parameters and multidimensional models were used to describe the changes in toxicity. Log Kow was able to explain about 40–60% of the variability in response data for aqueous exposures while molecular volume and aqueous solubility were less predictive. Likewise, the linear solvation energy relationship (LSER) model only explained 40–70% of the response variability, suggesting that factors other than solubility were most important for producing the observed response. Molecular connectivity was the most useful for describing the variability in the response. In the absence of sediment, 1χv and 3κ were best able to describe the variation in response among all compounds at each pH (70–90%). In the presence of sediment, even molecular connectivity could not describe the variability until the partitioning potential to sediment was accounted for by assuming equilibrium partitioning. After correcting for partitioning, the same molecular connectivity terms as in the aqueous exposures described most of the variability, 61–87%, except for the 11°C data where correlations were not significant. Molecular connectivity was a better tool than LSER or the unidimensional variables to explain the steric fitness of OP insecticides which was crucial to the toxicity.

  15. The effects of binary UV filter mixtures on the midge Chironomus riparius.

    Science.gov (United States)

    Ozáez, Irene; Morcillo, Gloria; Martínez-Guitarte, José-Luis

    2016-06-15

    Organic ultraviolet (UV) filters are used in a wide variety of products, including cosmetics, to prevent damage from UV light in tissues and industrial materials. Their extensive use has raised concerns about potential adverse effects in human health and aquatic ecosystems that accumulate these pollutants. To increase sun radiation protection, UV filters are commonly used in mixtures. Here, we studied the toxicity of binary mixtures of 4-methylbenzylidene camphor (4MBC), octyl-methoxycinnamate (OMC), and benzophenone-3 (BP-3), by evaluating the larval mortality of Chironomus riparius. Also molecular endpoints have been analyzed, including alterations in the expression levels of a gene related with the endocrine system (EcR, ecdysone receptor) and a gene related with the stress response (hsp70, heat shock protein 70). The results showed that the mortality caused by binary mixtures was similar to that observed for each compound alone; however, some differences in LC50 were observed between groups. Gene expression analysis showed that EcR mRNA levels increased in the presence of 0.1mg/L 4MBC but returned to normal levels after exposure to mixtures of 4MBC with 0.1, 1, and 10mg/L of BP-3 or OMC. In contrast, the hsp70 mRNA levels increased after exposure to the combinations tested of 4MBC and BP-3 or OMC mixtures. These data suggest that 4MBC, BP-3, and OMC may have antagonist effects on EcR gene transcription and a synergistic effect on hsp70 gene activation. This is the first experimental study to show the complex patterned effects of UV filter mixtures on invertebrates. The data suggest that the interactions within these chemicals mixtures are complex and show diverse effects on various endpoints. PMID:26971216

  16. UV filters induce transcriptional changes of different hormonal receptors in Chironomus riparius embryos and larvae.

    Science.gov (United States)

    Ozáez, Irene; Aquilino, Mónica; Morcillo, Gloria; Martínez-Guitarte, José-Luis

    2016-07-01

    Organic ultraviolet (UV) filters are emerging contaminants that are ubiquitous in fresh and marine aquatic systems due to their extensive use in cosmetics, plastics, paints, textiles, and many other industrial products. The estrogenic effects of organic UV filters have been long demonstrated in vertebrates, and other hormonal activities may be altered, according to more recent reports. The impact of UV filters on the endocrine system of invertebrates is largely unknown. We have previously reported that some UV filters may affect ecdysone-related genes in the aquatic insect Chironomus riparius, an ecotoxicologically important model organism. To further analyze other possible effects on endocrine pathways, we first characterized four pivotal genes related with hormonal pathways in insects; thereafter, these genes were assessed for alterations in transcriptional activity after exposure to 4-methylbenzylidene camphor (4MBC) or benzophenone-3 (BP-3), two extensively used sunscreens. We found that both chemicals disturbed the expression of all four genes analyzed: hormonal receptor 38 (HR38), methoprene-tolerant (Met), membrane-associate progesterone receptor (MAPR) and insulin-like receptor (INSR), measured by changes in mRNA levels by real-time PCR. An upregulatory effect at the genomic level was detected in different developmental stages. Interestingly, embryos appeared to be more sensitive to the action of the UV filters than larvae. Our results suggest that the risk of disruption through different endocrine routes is not negligible, considering the significant effects of UV filters on key hormonal receptor and regulatory genes. Further effort is needed to develop environmental risk assessment studies on these pollutants, particularly for aquatic invertebrate model organisms. PMID:27089421

  17. [Response of Sediment Micro Environment and Micro Interface to Physical Disturbance Intensity Under the Disturbance of Chironomus plumosus].

    Science.gov (United States)

    Shi, Xiao-dan; Li, Yong; Li, Da-peng; Wang, Ren; Deng, Meng; Huang, Yong

    2015-05-01

    The response of sediment micro environment and micro intertace to physical disturbance intensity under the physical and Chironomus plumosus disturbance was investigated by means of sediment Rhizon samplers and Unisense micro sensor system. The sediment and overlying water were taken from Meiliang bay of Taihu Lake. The results showed that the OPD reached up to 12.1 mm under the high intensity (240 r · min(-1)), while it was higher than 3. 8. mm under low intensity (60 r · min(-1)). The TOE, the difference of TOE and DOE, OPD, ORP and the difference of DO spatial distribution were all positively correlated with the physical disturbance intensity. The increasing magnitude and range of pH as well as the decreasing magnitude and range of ferrous followed the same response tendency. Within the 0-6 cm sediment, the water content and porosity as well as the microbial activity at the same depth increased with the increase of physical disturbance intensity. In addition, the degree of response of the above parameters to the physical disturbance intensity was weakened with the increase of sediment depth. It was suggested that Chironomus plumosus dug more and deeper galleries under high intensity physical disturbance. Therefore, the sediment micro environment and micro interface were transformed in the vertical direction of the sediment. PMID:26314108

  18. Ribosomal genes as early targets of cadmium-induced toxicity in Chironomus riparius larvae

    Energy Technology Data Exchange (ETDEWEB)

    Planello, R. [Biologia Ambiental, Facultad de Ciencias, Universidad Nacional de Educacion a Distancia, Senda del Rey 9, 28040, Madrid (Spain); Martinez-Guitarte, J.L. [Biologia Ambiental, Facultad de Ciencias, Universidad Nacional de Educacion a Distancia, Senda del Rey 9, 28040, Madrid (Spain); Morcillo, G. [Biologia Ambiental, Facultad de Ciencias, Universidad Nacional de Educacion a Distancia, Senda del Rey 9, 28040, Madrid (Spain)]. E-mail: gmorcillo@ccia.uned.es

    2007-02-01

    Cadmium is a widespread environmental pollutant that causes severe impacts in organisms. Although the effects of cadmium on aquatic insects have been studied in terms of their toxicity and changes in developmental parameters, little is known about its molecular and genetic effects. We have investigated the alterations in the pattern of gene expression provoked by acute exposure to cadmium in Chironomus riparius Mg. (Diptera, Chironomidae), a sentinel organism widely used in aquatic toxicity testing. The early cytotoxic effects were evaluated using immunocytochemistry and specific fluorescent probes in fourth instar larvae after 12 h of 10 mM cadmium treatments; under these conditions no significant effect on larvae mortality was detected until after 36 h of exposure. The changes in the pattern of gene expression were analysed by means of DNA/RNA hybrid antibodies in the polytene chromosomes from salivary gland cells. A decrease in the activity of the nucleolus is especially remarkable, accompanied by a significant reduction in size and the modification in nucleolar architecture, as shown by FISH. The inhibition of rDNA transcription was further evaluated by Northern blot analysis, which showed a marked decrease in the level of preribosomal rRNA (54% 45S 12 h). However, the BR genes, whose products are the giant polypeptides that constitute the silk-like secretion for constructing housing tubes, remain active. Simultaneously, decondensation and activation take place at some chromosomal regions, especially at the centromeres. The changes observed in the pattern of gene expression do not resemble those found after heat shock or other cell stressors. These data provide the first evidence that cadmium interacts with ribosomal genes and results in a drastic impairment of the functional activity of the nucleolus, an essential organelle for cellular survival. Therefore, the depletion of ribosomes would be a long-term effect of Cd-induced cellular damage. These findings may

  19. Ribosomal genes as early targets of cadmium-induced toxicity in Chironomus riparius larvae

    International Nuclear Information System (INIS)

    Cadmium is a widespread environmental pollutant that causes severe impacts in organisms. Although the effects of cadmium on aquatic insects have been studied in terms of their toxicity and changes in developmental parameters, little is known about its molecular and genetic effects. We have investigated the alterations in the pattern of gene expression provoked by acute exposure to cadmium in Chironomus riparius Mg. (Diptera, Chironomidae), a sentinel organism widely used in aquatic toxicity testing. The early cytotoxic effects were evaluated using immunocytochemistry and specific fluorescent probes in fourth instar larvae after 12 h of 10 mM cadmium treatments; under these conditions no significant effect on larvae mortality was detected until after 36 h of exposure. The changes in the pattern of gene expression were analysed by means of DNA/RNA hybrid antibodies in the polytene chromosomes from salivary gland cells. A decrease in the activity of the nucleolus is especially remarkable, accompanied by a significant reduction in size and the modification in nucleolar architecture, as shown by FISH. The inhibition of rDNA transcription was further evaluated by Northern blot analysis, which showed a marked decrease in the level of preribosomal rRNA (54% 45S 12 h). However, the BR genes, whose products are the giant polypeptides that constitute the silk-like secretion for constructing housing tubes, remain active. Simultaneously, decondensation and activation take place at some chromosomal regions, especially at the centromeres. The changes observed in the pattern of gene expression do not resemble those found after heat shock or other cell stressors. These data provide the first evidence that cadmium interacts with ribosomal genes and results in a drastic impairment of the functional activity of the nucleolus, an essential organelle for cellular survival. Therefore, the depletion of ribosomes would be a long-term effect of Cd-induced cellular damage. These findings may

  20. Survival, reproduction, and arsenic body burdens in Chironomus riparius exposed to arsenate and phosphate

    Energy Technology Data Exchange (ETDEWEB)

    Mogren, Christina L., E-mail: christina.mogren@email.ucr.edu [Department of Entomology, University of California, Riverside, 900 University Ave, Riverside, CA 92521 (United States); Kiparski, Guntram R. von; Parker, David R. [Department of Environmental Science, University of California, Riverside, 900 University Ave, Riverside, CA 92521 (United States); Trumble, John T. [Department of Entomology, University of California, Riverside, 900 University Ave, Riverside, CA 92521 (United States)

    2012-05-15

    Despite the increasing awareness of arsenic (As) contamination in surface waters worldwide, little is known about how As alone and in the presence of other chemicals affects aquatic insects. Larvae of Chironomus riparius were exposed in a laboratory investigation to factorial combinations of 0, 0.13, 2.0, 5.3, and 13 {mu}mol As l{sup -1} and 0, 0.15, and 15 {mu}mol PO{sub 4} l{sup -1} throughout development from first instar to pupal emergence. The time between male and female emergence increased from 1.8 {+-} 0.17 days to 2.9 {+-} 0.34 days with exposure at higher As levels. The highest As exposure also decreased the number of eggs per egg mass, which may affect population maintenance. For these parameters, there was no effect from PO{sub 4}, and no interaction between As and PO{sub 4}. Total As determination of larval and adult tissues was conducted using Hydride Generated Atomic Absorption Spectroscopy (HGAAS) and revealed concentrations ranging from 2.48 {+-} 0.363 to 30.5 {+-} 0.473 {mu}g/g and 1.03 {+-} 0.286 to 8.97 {+-} 0.662 {mu}g/g, respectively, indicating elimination of approximately 72% of total As body burdens between the fourth instar and adult stages. There was no effect of PO{sub 4}, indicating PO{sub 4} does not alter uptake of As in C. riparius. The potential for movement of As to terrestrial systems exists, though trophic transfer may be more likely during the aquatic larval stage. - Highlights: Black-Right-Pointing-Pointer We evaluate how sublethal concentrations of As and P affect C. riparius. Black-Right-Pointing-Pointer High As exposure significantly increased the time between male and female emergence. Black-Right-Pointing-Pointer High As exposure significantly decreased the number of eggs per egg mass. Black-Right-Pointing-Pointer Fourth instar larvae eliminate 72% of As body burdens before the adult stage.

  1. Examining the joint toxicity of chlorpyrifos and atrazine in the aquatic species: Lepomis macrochirus, Pimephales promelas and Chironomus tentans

    Energy Technology Data Exchange (ETDEWEB)

    Tyler Mehler, W.; Schuler, Lance J. [Fisheries and Illinois Aquaculture Center and Department of Zoology, Southern Illinois University at Carbondale, Carbondale, IL 62901-6511 (United States); Lydy, Michael J. [Fisheries and Illinois Aquaculture Center and Department of Zoology, Southern Illinois University at Carbondale, Carbondale, IL 62901-6511 (United States)], E-mail: mlydy@siu.edu

    2008-03-15

    The joint toxicity of chlorpyrifos and atrazine was compared to that of chlorpyrifos alone to discern any greater than additive response using both acute toxicity testing and whole-body residue analysis. In addition, acetylcholinesterase (AChE) inhibition and biotransformation were investigated to evaluate the toxic mode of action of chlorpyrifos in the presence of atrazine. The joint toxicity of atrazine and chlorpyrifos exhibited no significant difference in Lepomis macrochirus compared to chlorpyrifos alone; while studies performed with Pimephales promelas and Chironomus tentans, did show significant differences. AChE activity and biotransformation showed no significant differences between the joint toxicity of atrazine and chlorpyrifos and that of chlorpyrifos alone. From the data collected, the combination of atrazine and chlorpyrifos pose little additional risk than that of chlorpyrifos alone to the tested fish species. - The joint toxicity between atrazine and chlorpyrifos caused greater than additive responses in invertebrates, but the interactions in vertebrates was less pronounced.

  2. [Chromosomal variation in Chironomus plumosus L. (Diptera, Chironomidae) from populations of Bryansk region, Saratov region (Russia), and Gomel region (Belarus)].

    Science.gov (United States)

    Belyanina, S I

    2015-02-01

    Cytogenetic analysis was performed on samples of Chironomus plumosus L. (Diptera, Chironomidae) taken from waterbodies of various types in Bryansk region (Russia) and Gomel region (Belarus). Karyotypes of specimens taken from stream pools of the Volga were used as reference samples. The populations of Bryansk and Gomel regions (except for a population of Lake Strativa in Starodubskii district, Bryansk region) exhibit broad structural variation, including somatic mosaicism for morphotypes of the salivary gland chromosome set, decondensation of telomeric sites, and the presence of small structural changes, as opposed to populations of Saratov region. As compared with Saratov and Bryansk regions, the Balbiani ring in the B-arm of chromosome I is repressed in populations of Gomel region. It is concluded that the chromosome set of Ch. plumosus in a range of waterbodies of Bryansk and Gomel regions is unstable.

  3. Setting the reference for the use of Chironomus sancticaroli (Diptera: Chironomidae as bioindicator: Ontogenetic pattern of larval head structures

    Directory of Open Access Journals (Sweden)

    Débora Rebechi

    2012-04-01

    Full Text Available Species of Chironomidae are widely used as bioindicators of water quality, since their larvae undergo morphological deformities when in contact with sediment contaminated with chemicals. In this work we endeavored to study the morphology of head structures (antennae, mandible, mentum, pecten epipharyngis, ventromental plate and premandible throughout the development of the four larval instars of Chironomus sancticaroli Strixino & Strixino, 1981, which can be used in environmental impact analyses. Our results show that it is possible to differentiate among larval instars by doing a quantitative analysis on the number of striae on the ventromental plates. The six structures analyzed changed during larval ontogeny. These changes are part of the ontogeny of the immature stages not exposed to xenobiotics. We believe that the morphological pattern defined in this work can be used for comparisons with ontogenetic changes observed in field studies conducted in polluted environments.

  4. An inducible HSP70 gene from the midge Chironomus dilutus: Characterization and transcription profile under environmental stress

    Science.gov (United States)

    Karouna-Renier, N. K.; Rao, K.R.

    2009-01-01

    In the present study, we identified and characterized an inducible heat shock protein 70 (HSP70) from the midge Chironomus dilutus and investigated the transcriptional profile of the gene under baseline and environmentally stressful conditions. Using real-time quantitative reverse transcriptase-polymerase chain reaction (qRT-PCR), we observed increased expression of CD-HSP70-1 in response to both heat shock and copper stress. We also investigated the expression of this gene during midge development. All C. dilutus developmental stages expressed CD-HSP70-1 under normal conditions, although at extremely low levels. Phylogenetic analysis of the amino acid sequence demonstrated distinct clustering of this gene with inducible HSP70s from other insect species. ?? 2008 The Authors.

  5. Evaluation of mentum deformities of Chironomus spp. (Chironomidae: Diptera) larvae using modified toxic score index (MTSI) to assess the environmental stress in Juru River Basin, Penang, Malaysia.

    Science.gov (United States)

    Al-Shami, Salman Abdo; Salmah, Mad Rawi Che; Hassan, Ahmad Abu; Azizah, Mohd Nor Siti

    2011-06-01

    Morphological mentum deformities which represent sublethal effect of exposure to different types of pollutants were evaluated in Chironomus spp. larvae inhabiting three polluted rivers of Juru River Basin in northwestern peninsular Malaysia. Using mentum deformity incidences, the modified toxic score index (MTSI) was developed based on Lenat's toxic score index (TSI). The suggested MTSI was compared with TSI in terms of its effectiveness to identify different pollutants including heavy metals. The MTSI showed stronger relationship to total deformity incidence expressed as percentage. Additionally, the multivariate RDA model showed higher capability of MTSI to explain the variations in heavy metal contents of the river sediments. The MTSI was recommended in bioassessment of water and sediment quality using the mentum deformities of Chironomus spp. larvae from aquatic ecosystems receiving anthropogenic, agricultural, or industrial discharges.

  6. Evaluation of mentum deformities of Chironomus spp. (Chironomidae: Diptera) larvae using modified toxic score index (MTSI) to assess the environmental stress in Juru River Basin, Penang, Malaysia.

    Science.gov (United States)

    Al-Shami, Salman Abdo; Salmah, Mad Rawi Che; Hassan, Ahmad Abu; Azizah, Mohd Nor Siti

    2011-06-01

    Morphological mentum deformities which represent sublethal effect of exposure to different types of pollutants were evaluated in Chironomus spp. larvae inhabiting three polluted rivers of Juru River Basin in northwestern peninsular Malaysia. Using mentum deformity incidences, the modified toxic score index (MTSI) was developed based on Lenat's toxic score index (TSI). The suggested MTSI was compared with TSI in terms of its effectiveness to identify different pollutants including heavy metals. The MTSI showed stronger relationship to total deformity incidence expressed as percentage. Additionally, the multivariate RDA model showed higher capability of MTSI to explain the variations in heavy metal contents of the river sediments. The MTSI was recommended in bioassessment of water and sediment quality using the mentum deformities of Chironomus spp. larvae from aquatic ecosystems receiving anthropogenic, agricultural, or industrial discharges. PMID:20697808

  7. Potential use of acetylcholinesterase, glutathione-S-transferase and metallothionein for assessment of contaminated sediment in tropical chironomid, Chironomus javanus.

    Science.gov (United States)

    Somparn, A; Iwai, C B; Noller, B

    2015-11-01

    Heavy metals and organophosphorus insecticide is known to act as disruptors for the enzyme system, leading to physiologic disorders. The present study was conducted to investigate the potential use of these enzymes as biomarkers in assessment of contaminated sediments on tropical chironomid species. Acetylcholinesterase (AChE), glutathione-S-transferase (GST) and metallothionein (MT) activity was measured in the fourth-instar chironomid larvae, Chironomus javanus, Kieffer, after either 48-hr or 96-hr exposure to organophosphorus insecticide, chlorpyrifos (0.01- 0.25 mg kg(-1)) or heavy metal cadmium (0.1-25 mg kg(-1)). Exposure to chlorpyrifos (0.01 mg kg(-1)) at 48 and 96 hr significantly of AChE activity (64.2%-85.9%) and induced GST activity (33.9-63.8%) when compared with control (P GST activity (11.7-40%) and MT level (9.0%-70.5%) when compared with control (P impact of enzyme activity on chlorpyrifos and cadmium contamination. Activity of AChE, GST and MT could serve as potential biomarkers for assessment and biomonitoring the effects of insecticide and heavy metal contamination in tropical aquatic ecosystems. PMID:26688973

  8. Support for the evolutionary speed hypothesis from intraspecific population genetic data in the non-biting midge Chironomus riparius.

    Science.gov (United States)

    Oppold, Ann-Marie; Pedrosa, João A M; Bálint, Miklós; Diogo, João B; Ilkova, Julia; Pestana, João L T; Pfenninger, Markus

    2016-02-24

    The evolutionary speed hypothesis (ESH) proposes a causal mechanism for the latitudinal diversity gradient. The central idea of the ESH is that warmer temperatures lead to shorter generation times and increased mutation rates. On an absolute time scale, both should lead to an acceleration of selection and drift. Based on the ESH, we developed predictions regarding the distribution of intraspecific genetic diversity: populations of ectothermic species with more generations per year owing to warmer ambient temperatures should be more differentiated from each other, accumulate more mutations and show evidence for increased mutation rates compared with populations in colder regions. We used the multivoltine insect species Chironomus riparius to test these predictions with cytochrome oxidase I (COI) sequence data and found that populations from warmer regions are indeed significantly more differentiated and have significantly more derived haplotypes than populations from colder regions. We also found a significant correlation of the annual mean temperature with the population mutation parameter θ that serves as a proxy for the per generation mutation rate under certain assumptions. This pattern could be corroborated with two nuclear loci. Overall, our results support the ESH and indicate that the thermal regime experienced may be crucially driving the evolution of ectotherms and may thus ultimately govern their speciation rate. PMID:26888029

  9. Effects of TFM and Bayer 73 on in vivo oxygen consumption of the aquatic midge Chironomus tentans

    Science.gov (United States)

    Kawatski, J.A.; Dawson, V.K.; Reuvers, J.L.

    1974-01-01

    Exposure of fourth instar larvae of Chironomus tentans to 2.0-8.0 mg/liter of TFM (3-trifluormethyl-4-nitrophenol) for 6 hr at 22 A? 0.5 C in soft water resulted in a significantly increased rate of larval oxygen consumption compared to that of control larvae, as measured with the Warburg respirometer. Maximum stimulation of oxygen consumption occurred with 8.0 mg/liter of TFM, and 1.0 mg/liter of TFM had no measurable effect on basal respiration. When hardness of exposure water was progressively increased, the effect of TFM on oxygen consumption was diminished. Bayer 73 (5,2'-dichloro-4'-nitrosalicylanilide) stimulated oxygen consumption at 0.75 and 1.0 mg/liter, had no significant effect at concentrations less that 0.75 mg/liter, and inhibited oxygen consumption at concentrations of 1.20 mg/liter or greater. Mixtures of TFM and Bayer 73, in the ratio of 98:2, had no greater effect on oxygen consumption than TFM alone.

  10. Effects of anti-C23 (nucleolin) antibody on transcription of ribosomal DNA in Chironomus salivary gland cells

    Energy Technology Data Exchange (ETDEWEB)

    Egyhazi, E.; Pigon, A. (Karolinska Institutet, Stockholm (Sweden)); Chang, Jinhong; Ghaffari, S.H.; Dreesen, T.D.; Wellman, S.E.; Case, S.T.; Olson, M.O.J. (Univ. of Mississippi Medical Center, Jackson (USA))

    1988-10-01

    Protein C23 (also called nucleolin or 100-kDa nucleolar protein) is a major nucleolar phosphoprotein involved in ribosome biogenesis. To determine the effects of protein C23 on preribosomal RNA (pre-rRNA) synthesis anti-C23 antiserum was microinjected into nuclei of Chironomus tentans salivary glands. Transcription was measured by incubation of the glands with {sup 32}P-labeled RNA precursors followed by microdissection of nucleoli, RNA extraction, and electrophoretic analyses. Injection of the anti-C23 antibody caused a 2- to 3.5-fold stimulation of {sup 32}P incorporation into 38 S pre-rRNA. No stimulation was observed in salivary glands injected with preimmune serum or antiserum preabsorbed with protein C23. The stimulatory effect was selective for pre-rRNA as indicated by the lack of stimulation of {sup 32}P incorporation into extranucleolar RNA. Injection of the antiserum produced little or no effect on pre-RNA processing as measured by the relative amounts of {sup 32}P-labeled intermediate cleavage products of pre-rRNA in stimulated versus control glands. These results suggest that protein C23 not only is involved in ribosome assembly but also plays a role in regulating the transcription of the preribosomal RNA.

  11. Effects of phenol on metabolic activities and transcription profiles of cytochrome P450 enzymes in Chironomus kiinensis larvae.

    Science.gov (United States)

    Cao, C W; Sun, L L; Niu, F; Liu, P; Chu, D; Wang, Z Y

    2016-02-01

    Phenol, also known as carbolic acid or phenic acid, is a priority pollutant in aquatic ecosystems. The present study has investigated metabolic activities and transcription profiles of cytochrome P450 enzymes in Chironomus kiinensis under phenol stress. Exposure of C. kiinensis larvae to three sublethal doses of phenol (1, 10 and 100 µM) inhibited cytochrome P450 enzyme activity during the 96 h exposure period. The P450 activity measured after the 24 h exposure to phenol stress could be used to assess the level (low or high) of phenol contamination in the environment. To investigate the potential of cytochrome P450 genes as molecular biomarkers to monitor phenol contamination, the cDNA of ten CYP6 genes from the transcriptome of C. kiinensis were identified and sequenced. The open reading frames of the CYP6 genes ranged from 1266 to 1587 bp, encoding deduced polypeptides composed of between 421 and 528 amino acids, with predicted molecular masses from 49.01 to 61.94 kDa and isoelectric points (PI) from 6.01 to 8.89. Among the CYP6 genes, the mRNA expression levels of the CYP6EW3, CYP6EV9, CYP6FV1 and CYP6FV2 genes significantly altered in response to phenol exposure; therefore, these genes could potentially serve as biomarkers in the environment. This study shows that P450 activity combined with one or multiple CYP6 genes could be used to monitor phenol pollution.

  12. Chironomus plumosus larvae increase fluxes of denitrification products and diversity of nitrate-reducing bacteria in freshwater sediment

    DEFF Research Database (Denmark)

    Poulsen, Morten; W. V. Kofoed, Michael; H. Larsen, Lone;

    2014-01-01

    ) and the diversity and abundance of nitrate- and nitrous-oxide-reducing bacteria were investigated. Additionally, the diversity of actively nitrate- and nitrous-oxide-reducing bacteria was analyzed in the larval gut.The presence of larvae increased the total effluxes of N2O and N2+N2O up to 8.6- and 4.2-fold...... were found expressed, which may contribute to higher phylotype richness in colonized sediment. In contrast, phylotype richness of the nitrous oxide reductase gene nosZ was unaffected by the presence of larvae and very few nosZ phylotypes were expressed in the gut. Gene abundance of neither narG, nor......Benthic invertebrates affect microbial processes and communities in freshwater sediment by enhancing sediment-water solute fluxes and by grazing on bacteria. Using microcosms, the effects of larvae of thewidespread midge Chironomus plumosus on the efflux of denitrification products (N2O and N2+ N2O...

  13. Application of Tritiated Compounds to the Midge Chironomus and some Aspects of the Metabolism of Salivary Gland Chromosomes

    International Nuclear Information System (INIS)

    The investigations were carried out on the salivary gland chromosomes of Chironomus tentons. Tritiated compounds (H3-thymidine, H3-uridine, H3-amino-acids), injected into the haemolymph of the larvae should indicate the place of incorporation within the giant chromosomes. After fixation of the salivary glands autoradiographs of the squash-preparations were made. The autoradiographs show that giant chromosomes are most suitable to localize the activity at chromosomal structures with high resolution. DNA-synthesis (thymidine), RNA-synthesis (uridine) and protein-synthesis within the cell could be followed by determining the time and approximatively the quantity of incorporation: Contrary to the protein-synthesis, the DNA-synthesis and the RNA-synthesis are restricted to the chromosomes. The essential physiological activity of the chromosomes seems to be represented by RNA synthesis which takes place at certain distinct loci (nuceolar organizers, ''Balbiani-rings'', puffs, and other chromosomal bands). The report discusses some features of RNA synthesis. (author)

  14. The Balbiani ring 2 gene in Chironomus tentans is built from two types of tandemly arranged major repeat units with a common evolutionary origin

    OpenAIRE

    Wieslander, L.; Lendahl, U.

    1983-01-01

    The internal structure of the 37 kb long Balbiani ring 2 (BR 2) gene in Chironomus tentans has been studied by analysis of a collection of cloned cDNA sequences and in genomic Southern blot analysis with the cDNA sequences used as probes. The BR 2 gene contains two types of tandemly arranged major repeat units ˜200 bp long, represented in our study by the pCt 7 and the pCt 63 cDNA inserts. The pCt 7 major repeat units are arranged in one or possibly a few blocks and cover ˜10 kb of the gene; ...

  15. Evolutionary ecotoxicology of perfluoralkyl substances (PFASs) inferred from multigenerational exposure: a case study with Chironomus riparius (Diptera, Chironomidae).

    Science.gov (United States)

    Stefani, F; Rusconi, M; Valsecchi, S; Marziali, L

    2014-11-01

    A multigeneration toxicity test on Chironomus riparius was performed with the aim of investigating the evolutionary consequences of exposure to perfluoralkyl substances (perfluorooctane sulfonic acid, PFOS; perfluorooctanoic acid, PFOA; perfluorobutane sulfonate, PFBS). Six-hundred larvae were bred per treatment and per generation until emergence and egg deposition under a nominal concentration of 10μg/L of contaminants. Newborn larvae were used to start the next generation. Evolution of genetic variability was evaluated along a total of 10 consecutive generations based on 5 microsatellite loci. Analysis of life-history traits (survival, sex ratio and reproduction) was also carried out. Rapid genetic variability reduction was observed in all treatments, including controls, across generations due to the test conditions. Nevertheless, an increased mutation rate determined a stronger conservation of genetic variability in PFOS and, at minor extent, in PFBS exposed populations compared to controls. No significant effects were induced by exposure to PFOA. Direct mutagenicity or induced stress conditions may be at the base of increased mutation rate, indicating the potential risk of mutational load caused by exposure to PFOS and PFBS. The test provided the opportunity to evaluate the use of approximate Bayesian computation (ABC) and coalescent approaches in evolutionary ecotoxicology. A weak performance was evidenced for ABC, either in terms of bias or dispersion of effective population sizes and of estimates of mutation rate. On the contrary, coalescent simulations proved the sensitivity of traditional genetic endpoints (i.e. heterozygosity and number of alleles) to the alteration of mutation rate, but not to erosion of genetic effective size.

  16. Overexpression of long non-coding RNAs following exposure to xenobiotics in the aquatic midge Chironomus riparius

    International Nuclear Information System (INIS)

    Non-coding RNAs (ncRNAs) represent an important transcriptional output of eukaryotic genomes. In addition to their functional relevance as housekeeping and regulatory elements, recent studies have suggested their involvement in rather unexpected cellular functions. The aim of this work was to analyse the transcriptional behaviour of non-coding RNAs in the toxic response to pollutants in Chironomus riparius, a reference organism in aquatic toxicology. Three well-characterized long non-coding sequences were studied: telomeric repeats, Cla repetitive elements and the SINE CTRT1. Transcription levels were evaluated by RT-PCR after 24-h exposures to three current aquatic contaminants: bisphenol A (BPA), benzyl butyl phthalate (BBP) and the heavy metal cadmium (Cd). Upregulation of telomeric transcripts was found after BPA treatments. Moreover, BPA significantly activated Cla transcription, which also appeared to be increased by cadmium, whereas BBP did not affect the transcription levels of these sequences. Transcription of SINE CTRT1 was not altered by any of the chemicals tested. These data are discussed in the light of previous studies that have shown a response by long ncRNAS (lncRNAs) to cellular stressors, indicating a relationship with environmental stimuli. Our results demonstrated for the first time the ability of bisphenol A to activate non-coding sequences mainly located at telomeres and centromeres. Overall, this study provides evidence that xenobiotics can induce specific responses in ncRNAs derived from repetitive sequences that could be relevant in the toxic response, and also suggests that ncRNAs could represent a novel class of potential biomarkers in toxicological assessment.

  17. Ultraviolet filters differentially impact the expression of key endocrine and stress genes in embryos and larvae of Chironomus riparius.

    Science.gov (United States)

    Ozáez, Irene; Morcillo, Gloria; Martínez-Guitarte, José-Luis

    2016-07-01

    Several organic UV filters have hormonal activity in vertebrates, as demonstrated in fishes, rodents and human cells. Despite the accumulation of filter contaminants in aquatic systems, research on their effects on the endocrine systems of freshwaters invertebrates is scarce. In this work, the effects of five frequently used UV filters were investigated in embryos and larvae of Chironomus riparius, which is a reference organism in ecotoxicology. LC50 values for larvae as well as the percentage of eclosion of eggs were determined following exposures to: octyl-p-methoxycinnamate (OMC) also known as 2-ethylhexyl-4-methoxycinnamate (EHMC); 4-methylbenzylidene camphor (4MBC); 4-hydroxybenzophenone (4HB); octocrylene (OC); and octyldimethyl-p-aminobenzoate (OD-PABA). To assess sublethal effects, expression levels of the genes coding for the ecdysone receptor (EcR) and heat shock protein HSP70 were investigated as biomarkers for endocrine and stress effects at the cellular level. Life-stage-dependent sensitivity was found. In embryos, all of the UV filters provoked a significant overexpression of EcR at 24h after exposure. OC, 4MBC and OD-PABA also triggered transcriptional activation of the hsp70 stress gene in embryos. In contrast, in larvae, only 4MBC and OMC/EHMC increased EcR and hsp70 mRNA levels and OD-PABA upregulated only the EcR gene. These results revealed that embryos are particularly sensitive to UV filters, which affect endocrine regulation during development. Most UV filters also triggered the cellular stress response, and thus exhibit proteotoxic effects. The differences observed between embryos and larvae and the higher sensitivity of embryos highlight the importance of considering different life stages when evaluating the environmental risks of pollutants, particularly when analyzing endocrine effects. PMID:26994811

  18. Overexpression of long non-coding RNAs following exposure to xenobiotics in the aquatic midge Chironomus riparius

    Energy Technology Data Exchange (ETDEWEB)

    Martinez-Guitarte, Jose-Luis, E-mail: jlmartinez@ccia.uned.es [Grupo de Biologia y Toxicologia Ambiental, Facultad de Ciencias, Universidad Nacional de Educacion a Distancia, UNED, Senda del Rey 9, 28040 Madrid (Spain); Planello, Rosario; Morcillo, Gloria [Grupo de Biologia y Toxicologia Ambiental, Facultad de Ciencias, Universidad Nacional de Educacion a Distancia, UNED, Senda del Rey 9, 28040 Madrid (Spain)

    2012-04-15

    Non-coding RNAs (ncRNAs) represent an important transcriptional output of eukaryotic genomes. In addition to their functional relevance as housekeeping and regulatory elements, recent studies have suggested their involvement in rather unexpected cellular functions. The aim of this work was to analyse the transcriptional behaviour of non-coding RNAs in the toxic response to pollutants in Chironomus riparius, a reference organism in aquatic toxicology. Three well-characterized long non-coding sequences were studied: telomeric repeats, Cla repetitive elements and the SINE CTRT1. Transcription levels were evaluated by RT-PCR after 24-h exposures to three current aquatic contaminants: bisphenol A (BPA), benzyl butyl phthalate (BBP) and the heavy metal cadmium (Cd). Upregulation of telomeric transcripts was found after BPA treatments. Moreover, BPA significantly activated Cla transcription, which also appeared to be increased by cadmium, whereas BBP did not affect the transcription levels of these sequences. Transcription of SINE CTRT1 was not altered by any of the chemicals tested. These data are discussed in the light of previous studies that have shown a response by long ncRNAS (lncRNAs) to cellular stressors, indicating a relationship with environmental stimuli. Our results demonstrated for the first time the ability of bisphenol A to activate non-coding sequences mainly located at telomeres and centromeres. Overall, this study provides evidence that xenobiotics can induce specific responses in ncRNAs derived from repetitive sequences that could be relevant in the toxic response, and also suggests that ncRNAs could represent a novel class of potential biomarkers in toxicological assessment.

  19. In situ bioassays with Chironomus riparius larvae to biomonitor metal pollution in rivers and to evaluate the efficiency of restoration measures in mine areas

    International Nuclear Information System (INIS)

    In this study we evaluate the ability of an in situ bioassay with Chironomus riparius larvae, using larval development and growth as endpoints, to biomonitor water quality and to assess the biological recovery of metal contaminated freshwater ecosystems of mine areas that are subject of restoration measures. The bioassay was carried out in streams located near an abandoned goldmine in North Portugal, throughout an environmental rehabilitation of the mine (2002-2004). During this period, a decrease in the inhibition of larval growth in the metal contaminated stream was observed. The bioassay was also performed in streams located near an active tungsten mine in Central Portugal. Larval growth and development were highly inhibited in the stream that receives acid drainage from the tungsten mine and treated water from the AMD treatment station. The results indicate that the bioassay can be used to evaluate the efficiency of environmental restoration measures in mining areas. - In situ bioassays with Chironomus riparius larvae can be a suitable tool to monitor restoration efficiency after a long time of metallic sediment contamination

  20. The ribosome biogenesis pathway as an early target of benzyl butyl phthalate (BBP) toxicity in Chironomus riparius larvae.

    Science.gov (United States)

    Herrero, Óscar; Planelló, Rosario; Morcillo, Gloria

    2016-02-01

    Butyl benzyl phthalate (BBP) is a ubiquitous contaminant whose presence in the environment is expected for decades, since it has been extensively used worldwide as a plasticizer in the polyvinyl chloride (PVC) industry and the manufacturing of many other products. In the present study, the interaction of BBP with the ribosome biogenesis pathway and the general transcriptional profile of Chironomus riparius aquatic larvae were investigated by means of changes in the rDNA activity (through the study of the internal transcribed spacer 2, ITS2) and variations in the expression profile of ribosomal protein genes (rpL4, rpL11, and rpL13) after acute 24-h and 48-h exposures to a wide range of BBP doses. Furthermore, cytogenetic assays were conducted to evaluate the transcriptional activity of polytene chromosomes from salivary gland cells, with special attention to the nucleolus and the Balbiani rings (BRs) of chromosome IV. BBP caused a dose and time-dependent toxicity in most of the selected biomarkers, with a general depletion in the gene expression levels and the activity of BR2 after 48-h treatments. At the same time, decondensation and activation of some centromeres took place, while the activity of nucleolus remained unaltered. Withdrawal of the xenobiotic allowed the larvae to reach control levels in the case of rpL4 and rpL13 genes, which were previously slightly downregulated in 24-h tests. These data provide the first evidence on the interaction of BBP with the ribosome synthesis pathways, which results in a significant impairment of the functional activity of ribosomal protein genes. Thus, the depletion of ribosomes would be a long-term effect of BBP-induced cellular damage. These findings may have important implications for understanding the adverse biological effects of BBP in C. riparius, since they provide new sensitive biomarkers of BBP exposure and highlight the suitability of this organism for ecotoxicological risk assessment, especially in aquatic

  1. Transcriptional profiling induced by pesticides employed in organic agriculture in a wild population of Chironomus riparius under laboratory conditions.

    Science.gov (United States)

    Lencioni, Valeria; Grazioli, Valentina; Rossaro, Bruno; Bernabò, Paola

    2016-07-01

    Copper (Cu) and azadirachtin (AZA-A+B) are pesticides allowed in organic agriculture whose environmental risk and toxicity for aquatic wildlife is only partially known. Reverse Transcription Polymerase Chain Reaction was used to assess the molecular effect of acute and short-term exposure (3, 24h) of Cu (0.01, 0.05, 1, 10, 25mgl(-1)) and AZA-A+B (0.2, 0.3, 0.4, 0.5, 1mgl(-1)) on the expression of five candidate genes (hsp70, hsc70, hsp40, hsp10 and cyP450) in a non-target species, Chironomus riparius. Fourth-instar larvae were collected from a mountain stream polluted by agricultural land run-off. All genes were responsive to both pesticides but each gene had a specific response to the different experimental concentrations and exposure times. A few similarities in transcriptional profiling were observed, such as a linear concentration-dependent response of hsp70 after 24h of exposure (at ≥1mgl(-1) of Cu and ≥0.2mgl(-1) of AZA-A+B) and an up-regulation regardless of the concentration of hsc70 after 24h of exposure (at ≥0mgl(-1) of Cu and ≥0.2mgl(-1) of AZA-A+B and the up-regulation of hsp70 after 3h of exposure at ~LC50 (Cu-LC50=26.1±2.5mgl(-1), AZA-A+B-LC50=1.1±0.2mgl(-1)). According to the results, hsp40, hsp10 and cyP450 may be defined as pesticide-dependent (i.e., hsp40 and hsp10 seemed to responded mainly to AZA-A+B and cyP450 to Cu), while hsc70 as time-dependent regardless of the pesticide (i.e., hsc70 responded only after 24h of treatment with Cu and AZA-A+B). This study gives new insights on the potential role of the C. riparius's hsps and cyP450 genes as sensitive biomarkers for freshwater monitoring. PMID:26994805

  2. TOXICITY OF TWO HERBICIDES 2,4 -D DIMETHYLAMINE AND BENSULFURON METHYL TO RICE FIELD CHIRONOMUS KIIENSIS (TOKUNAGA) ( DIPTERA: CHIRONOMIDAE)

    Institute of Scientific and Technical Information of China (English)

    Al-Shami S A; Che Salmah M R; Siti Azizah M N; Abu Hassan A; Azmi M

    2006-01-01

    Fourth instar larvae of Chironomus kiiensis(Tokunaga) were exposed to various concentrations of two commonly used herbicides: 2,4 - D Dimethylamine and Bensulfuron methyl in the rice fields. The bioassay experiment was carried out in a rearing unit in the laboratory at a room temperature ( (27 ± 2) ℃ ). A thin layer of sand sediments and tissue papers were provided as substrate in each unit. Each concentration of all herbicides was prepared in 250 mL distilled water. The experiment was performed in triplicate and 20 chironomid larvae were placed in each rearing unit. The larvae were fed with fish food (Sanyuichiban(R)) at 2 d intervals and all units were aerated by air pumps. The experiment was monitored every 24 h for mortality of C. kiiensis. The 2,4 - D Dimethylamine bioassay was carried out for 24 h while Bensulfuron methyl was run for 72 h. Dead larvae, pupae and living or dead adults were counted and removed daily.The LC50 of 2,4 - D Dimethylamine was 2 638 mg ai L-1, more than 2 000 times higher than the recommended dose of 0.753 mg ai L-1 used for controlling weeds in the rice field. Bensulfuron methyl was more toxic than the 2,4 - D Dimethylamine. The LC50 of the Bensulfuron methyl was recorded at 1.29 mg ai L-1, and approximately was more 20 times than that of the recommended dose of 0. 057 mg ai L-1. Bensulfuron methyl was found to be slow acting. The mortality of the larvae was only observed after 72 h. However, this herbicide interfered with the emergence of C. kiiensis to adults at and above the recommended dose used in the rice fields. Based on their LC50 values, this study showed that applying these herbicides in the rice fields at doses recommended by the manufacturers was safe for C. kiiensis and presumably to other living organisms in the water.

  3. Carbon and nitrogen stable isotope ratios analysis of food sources for Chironomus acerbiphilus larvae (Diptera Chironomidae) in strongly acidic lake Katanuma

    International Nuclear Information System (INIS)

    The food sources for Chironomus acerbiphilus larvae (Diptera Chironomidae) were analyzed using carbon and nitrogen stable isotope ratios in Lake Katanuma. Lake Katanuma is a volcanic and strongly acidic lake (average pH 2.2). In Lake Katanuma, potential sources of diets for the chironomid larvae are limited including a benthic diatom (Pinnularia braunii), a phytoplankton (Chlamydomonas acidophila), sulfate oxidizing bacteria, and vascular plants supplied from vegetation surrounding the lake. Based on the average carbon and nitrogen isotope ratios among these potential sources and sediment, benthic diatoms were considered to be most probable food source of the chironomid larvae. δ13C values of the chironomid were significantly different among seasons and habitat depths, suggesting that diet of C. acerbiphilus changed seasonally and with habitat depth. (author)

  4. Chironomus plumosus' påvirkning af næringsstofflukse i restaurerede søer

    DEFF Research Database (Denmark)

    Kristensen, Thomas Boll; Reitzel, Kasper; Andersen, Frede Østergaard;

    Den interne næringsstofbelastning af en række danske søer har betydet at disse søer er forblevet i en uklar, algedomineret tilstand til trods for reduktioner i mængden af tilførte næringsstoffer. I mange tilfælde er der derfor efterfølgende lavet et eller flere restaureringsindgreb for at skabe e....... plumosus efter længere tid vil øge bindingen af fosfor.   Andersen,F.Ø.; Jørgensen,M.; Jensen, H.S. (2006). The influence of Chironomus plumosus larvae on nutrient fluxes and phosphorus fractions in aluminum treated lake sediment. Water, Air, and Soil Pollution: Focus....

  5. Ecological and Genetic Relationship of Chironomus circumdatus (Diptera, Chironomidae From Mitochondrial Cytochrome Oxidase Subunit I in Chiang Mai Province, Northern Thailand

    Directory of Open Access Journals (Sweden)

    W. Roongruangwongse

    2012-04-01

    Full Text Available This study provides means for more accurate identification of Chironomus circumdatus species for environmental and ecological management by Population of C. circumdatus (86 individuals and water samples were collected from three different sites of Chiang Mai Province, Thailand. Specimens of Einfeldia sp. were used as an initial out group. The genetic relationship of C. circumdatus specimens from these sources was determined by using DNA sequence analysis of partial mtDNA gene’s Cytochrome Oxidase Subunit I (COI. Analysis of genetic distance on the basis of sequence difference for COI mitochondrial gene showed very little genetic difference and the data from phylogenetic analysis revealed a very large genetic difference among all populations of this species for the COI gene sequences. In addition, NJ tree was related to with physicochemical parameters of the water samples.

  6. Effects of clay minerals and organic matter in formulated sediments on the bioavailability of sediment-associated uranium to the freshwater midge, Chironomus dilutus

    International Nuclear Information System (INIS)

    It is well established that bioavailability influences metal toxicity in aquatic ecosystems. However, the factors and mechanisms that influence uranium (U) bioavailability and toxicity in sediment have not been thoroughly evaluated, despite evidence that suggests different sediment components can influence the sorption and interaction of some metals. Given that dissolved U is generally accepted as being the primary bioavailable fraction of U, it is hypothesized that adsorption and interaction of U with different sediment components will influence the bioavailability of U in sediment. We investigated the effects of key sediment physicochemical properties on the bioavailability of U to a model freshwater benthic invertebrate, Chironomus dilutus. Several 10-day spiked sediment bioaccumulation experiments were performed, exposing C. dilutus larvae to a variety of formulated sediments spiked with different concentrations of U (5, 50 and/or 200 mg U/kg d.w.). Mean accumulation of U in C. dilutus larvae decreased significantly from 1195 to 10 mg U/kg d.w. as kaolin clay content increased from 0% to 60% in sediment spiked with 50 mg U/kg d.w. Similarly, higher organic matter content also resulted in a significant reduction of U bioaccumulation in C. dilutus larvae, indicating a reduction in U bioavailability. Concentrations of U in both the overlying water and sediment pore water displayed a strong positive relationship to U bioaccumulation in C. dilutus larvae (r2 = 0.77, p < 0.001 and r2 = 0.57, p < 0.001, respectively) for all experiments, while total U concentrations in the sediment had a poor relationship to U bioaccumulation (r2 = 0.10, p = 0.028). Results from this research confirm that sediment clay and organic matter content play a significant role in altering U bioavailability, which is important in informing risk assessments of U contaminated sites and in the development of site-specific sediment quality guidelines for U. - Highlights: • We examined the role

  7. Effects of clay minerals and organic matter in formulated sediments on the bioavailability of sediment-associated uranium to the freshwater midge, Chironomus dilutus

    Energy Technology Data Exchange (ETDEWEB)

    Crawford, Sarah E., E-mail: sarah.crawford@usask.ca [Toxicology Centre, University of Saskatchewan, 44 Campus Drive, Saskatoon, SK S7N 5B3 (Canada); Liber, Karsten, E-mail: karsten.liber@usask.ca [Toxicology Centre, University of Saskatchewan, 44 Campus Drive, Saskatoon, SK S7N 5B3 (Canada); School of Environment and Sustainability, 117 Science Place, University of Saskatchewan, Saskatoon, SK S7N 5C8 (Canada); Institute of Loess Plateau, 92 Wucheng Road, Shanxi University, Taiyuan, Shanxi 030006 (China)

    2015-11-01

    It is well established that bioavailability influences metal toxicity in aquatic ecosystems. However, the factors and mechanisms that influence uranium (U) bioavailability and toxicity in sediment have not been thoroughly evaluated, despite evidence that suggests different sediment components can influence the sorption and interaction of some metals. Given that dissolved U is generally accepted as being the primary bioavailable fraction of U, it is hypothesized that adsorption and interaction of U with different sediment components will influence the bioavailability of U in sediment. We investigated the effects of key sediment physicochemical properties on the bioavailability of U to a model freshwater benthic invertebrate, Chironomus dilutus. Several 10-day spiked sediment bioaccumulation experiments were performed, exposing C. dilutus larvae to a variety of formulated sediments spiked with different concentrations of U (5, 50 and/or 200 mg U/kg d.w.). Mean accumulation of U in C. dilutus larvae decreased significantly from 1195 to 10 mg U/kg d.w. as kaolin clay content increased from 0% to 60% in sediment spiked with 50 mg U/kg d.w. Similarly, higher organic matter content also resulted in a significant reduction of U bioaccumulation in C. dilutus larvae, indicating a reduction in U bioavailability. Concentrations of U in both the overlying water and sediment pore water displayed a strong positive relationship to U bioaccumulation in C. dilutus larvae (r{sup 2} = 0.77, p < 0.001 and r{sup 2} = 0.57, p < 0.001, respectively) for all experiments, while total U concentrations in the sediment had a poor relationship to U bioaccumulation (r{sup 2} = 0.10, p = 0.028). Results from this research confirm that sediment clay and organic matter content play a significant role in altering U bioavailability, which is important in informing risk assessments of U contaminated sites and in the development of site-specific sediment quality guidelines for U. - Highlights: • We

  8. The plasticizer benzyl butyl phthalate (BBP) alters the ecdysone hormone pathway, the cellular response to stress, the energy metabolism, and several detoxication mechanisms in Chironomus riparius larvae.

    Science.gov (United States)

    Herrero, Óscar; Planelló, Rosario; Morcillo, Gloria

    2015-06-01

    Butyl benzyl phthalate (BBP) has been extensively used worldwide as a plasticizer in the polyvinyl chloride (PVC) industry and the manufacturing of many other products, and its presence in the aquatic environment is expected for decades. In the present study, the toxicity of BBP was investigated in Chironomus riparius aquatic larvae. The effects of acute 24-h and 48-h exposures to a wide range of BBP doses were evaluated at the molecular level by analysing changes in genes related to the stress response, the endocrine system, the energy metabolism, and detoxication pathways, as well as in the enzyme activity of glutathione S-transferase. BBP caused a dose and time-dependent toxicity in most of the selected biomarkers. 24-h exposures to high doses affected larval survival and lead to a significant response of several heat-shock genes (hsp70, hsp40, and hsp27), and to a clear endocrine disrupting effect by upregulating the ecdysone receptor gene (EcR). Longer treatments with low doses triggered a general repression of transcription and GST activity. Furthermore, delayed toxicity studies were specially relevant, since they allowed us to detect unpredictable toxic effects, not immediately manifested after contact with the phthalate. This study provides novel and interesting results on the toxic effects of BBP in C. riparius and highlights the suitability of this organism for ecotoxicological risk assessment, especially in aquatic ecosystems. PMID:25725395

  9. Identification, characterization and expression profiles of Chironomus riparius glutathione S-transferase (GST) genes in response to cadmium and silver nanoparticles exposure

    Energy Technology Data Exchange (ETDEWEB)

    Nair, Prakash M. Gopalakrishnan [School of Environmental Engineering and Graduate School of Energy and Environmental System Engineering, University of Seoul, 90 Jeonnong-dong, Dongdaemun-gu, Seoul 130-743 (Korea, Republic of); Choi, Jinhee, E-mail: jinhchoi@uos.ac.kr [School of Environmental Engineering and Graduate School of Energy and Environmental System Engineering, University of Seoul, 90 Jeonnong-dong, Dongdaemun-gu, Seoul 130-743 (Korea, Republic of)

    2011-02-15

    In this study, we report the identification and characterization of 13 cytosolic GST genes in Chironomus riparius from Expressed Sequence Tags (ESTs) database generated using pyrosequencing. Comparative and phylogenetic analyses were undertaken with Drosophila melanogaster and Anopheles gambiae GSTs and 3 Delta, 4 Sigma, 1 each in Omega, Epsilon, Theta, Zeta and 2 unclassified classes of GSTs were identified and characterized. The relative mRNA expression levels of all of the C. riparius GSTs (CrGSTs) genes under different developmental stages were varied with low expression in the larval stage. The antioxidant role of CrGSTs was studied by exposing fourth instar larvae to a known oxidative stress inducer Paraquat and the relative mRNA expression to different concentrations of cadmium (Cd) and silver nanoparticles (AgNPs) for various time intervals were also studied. All the CrGSTs showed up- or down regulation to varying levels based upon the concentration, and duration of exposure. The highest mRNA expression was noticed in Delta3, Sigma4 and Epsilon1 GST class in all treatments. These results show the role of CrGST genes in defense against oxidative stress and its potential as a biomarker to Cd and AgNPs exposure.

  10. Spinosad and neem seed kernel extract as bio-controlling agents for malarial vector,Anopheles stephensi and non-biting midge,Chironomus circumdatus

    Institute of Scientific and Technical Information of China (English)

    Kumar AN; Murugan K; Madhiyazhagan P; Prabhu K

    2011-01-01

    Objective:Midge egg masses are reported to support non-pathogenic strains of the cholera pathogen,Vibrio cholera (V. cholera). Mosquito born diseases have been reported to cause millions of death worldwide. The present research reveals the toxicity effect of spinosad and neem seed kernel extract (NSKE)against different larval stages ofAnopheles stephensi (An. stephensi) andChironomus circumdatus (Ch. circumdatus).Methods: The neem seeds were collected from Marudamalai hills, Bharathiar University, Coimbatore, India. Neem seed kernels were powdered, extracted and diluted for different concentrations (2 ppm to10 ppm). Spinosad was purchased from Kalpatharu pesticide Limited, Coimbatore, Tamil Nadu, India and thoroughly mixed with distilled water to prepare various concentrations (0.01 to0.08 ppm) and used for bioassay.Results: The results depict that spinosad is more toxic in lower concentrations when compared toNSKE and mosquitoes are more susceptible than chironomids. Lethal concentrations were evaluated using the observed mortality. The lowest LC50 value obtained from spinosad againstAn. stephensi and Ch. circumdatus were0.002 05 ppm and0.008 91 ppm. This study investigated on effect of Spinosad andNSKE on the biology of mosquito. The immature stages of both species were susceptible to Spinosad andNSKE. Spinosad andNSKE in individual as well as combined treatment provided additional days in development for mosquitoes.Conclusions:The results conclude that Spinosad andNSKE are potential larvicides against An. stephensi andCh. circumdatus.

  11. Effects of Lumbriculus variegatus (Annelida, Oligochaete) bioturbation on zinc sediment chemistry and toxicity to the epi-benthic invertebrate Chironomus tepperi (Diptera: Chironomidae).

    Science.gov (United States)

    Colombo, Valentina; Pettigrove, Vincent J; Hoffmann, Ary A; Golding, Lisa A

    2016-09-01

    Classical laboratory-based single-species sediment bioassays do not account for modifications to toxicity from bioturbation by benthic organisms which may impact predictions of contaminated sediment risk to biota in the field. This study aims to determine the effects of bioturbation on the toxicity of zinc measured in a standard laboratory bioassay conducted with chironomid larvae (Chironomus tepperi). The epi-benthic chironomid larvae were exposed to two different levels of sediment contamination (1600 and 1980 mg/kg of dry weight zinc) in the presence or absence of annelid worms (Lumbriculus variegatus) which are known to be tolerant to metal and to have a large impact on sediment properties through bioturbation. Chironomids had 5-6x higher survival in the presence of L. variegatus which shows that bioturbation had a beneficial effect on the chironomid larvae. Chemical analyses showed that bioturbation induced a flux of zinc from the pore water into the water column, thereby reducing the bioavailability of zinc in pore water to the chironomid larvae. This also suggested that pore water was the major exposure path for the chironomids to metals in sediment. During the study, annelid worms (Oligochaetes) produced a thin layer of faecal pellets at the sediment surface, a process known to: (i) create additional adsorption sites for zinc, thus reducing its availability, (ii) increase the microbial abundance that in turn could represent an additional food source for opportunistic C. tepperi larvae, and (iii) modify the microbial community's structure and alter the biogeochemical processes it governs thus indirectly impact zinc toxicity. This study represents a contribution in recognising bioturbating organisms as "ecological engineers" as they directly and indirectly influence metal bioavailability and impact other sediment-inhabiting species. This is significant and should be considered in risk assessment of zinc levels (and other metals) in contaminated sediment

  12. Evaluación de los efectos tóxicos de ftalatos sobre poblaciones naturales de Chironomus riparius (Diptera: implicaciones en estudios de ecotoxicidad

    Directory of Open Access Journals (Sweden)

    O Herrero

    2014-01-01

    Full Text Available Los quironómidos, un género de mosquitos no picadores, son organismos centinela en la evaluación de la calidad de las aguas y un modelo de relevancia ecotoxicológica para el estudio de los efectos de contaminantes ambientales. Son todavía muy escasos los trabajos con poblaciones naturales de este organismo en los que se valore la utilidad de biomarcadores moleculares en el análisis de la salud de individuos expuestos a múltiples variables de estrés. Nuestros resultados muestran que exposiciones de larvas de poblaciones naturales de Chironomus riparius a di (2-etilhexil ftalato (DEHP y butil bencil ftalato (BBP, dos compuestos incluidos por la ECHA en la lista de sustancias de muy alta preocupación, provocan alteraciones rápidas en la expresión de diferentes genes relacionados con la respuesta celular de estrés (hsp70 y hsc70, la ruta hormonal (EcR y ERR y los mecanismos de destoxicación (CYP4G, así como en la actividad enzimática de GST. Ambos compuestos provocan respuestas diferentes en estas dianas, especialmente en las exposiciones más prolongadas, y tienen la capacidad de producir efectos tóxicos retardados. Son de especial relevancia los resultados que muestran la alteración de la ruta hormonal de la ecdisona, confirmando la capacidad disruptora endocrina en insectos de estos ftalatos. Por último, existen diferencias respecto a datos previos obtenidos con larvas de laboratorio, tanto en la toxicidad de DEHP y BBP como en el comportamiento de algunas dianas, lo que acentúa la necesidad de llevar a cabo análisis con diferentes poblaciones para conseguir una aproximación más realista a los efectos de contaminantes.

  13. Effect of acute exposure to cadmium on the expression of heat-shock and hormone-nuclear receptor genes in the aquatic midge Chironomus riparius

    International Nuclear Information System (INIS)

    Cadmium is a widespread and highly toxic pollutant of particular ecotoxicological relevance for aquatic ecosystems where it accumulates. To identify biomarkers for ecotoxicity monitoring, the effect of cadmium on the expression of different genes related to the stress response as well as to the ecdysone hormone-signalling pathway was studied in the aquatic larvae of Chironomus riparius (Diptera, Chironomidae), a standard test organism in aquatic toxicology testing. Reverse Transcription Polymerase Chain Reaction (RT-PCR) was used to evaluate the effects of acute and short-term cadmium exposures (10 mM CdCl2, 12 h and 24 h) on the expression of hsp70, hsc70, hsp90 and hsp40 genes, as well as on that of the ecdysone hormonal-receptor genes (EcR and usp). A significant 3-fold increase in the level of hsp70 gene transcripts was induced by the treatment, whereas neither the other stress genes tested (hsp90 and hsp40) nor the constitutive form of hsp70, hsc70, was affected in the larvae exposed to cadmium. These results show that hsp70 is differentially activated to other environmentally regulated heat-shock genes, and constitutes a biomarker of exposure to this toxic metal. In addition, we also found that cadmium is able to alter the expression of the ecdysone receptor gene (EcR), whose mRNA level is significantly increased whereas usp levels remained unaltered. This finding, evidenced for the first time in invertebrates, supports the view that cadmium has the ability to mimic the effect of the hormone by the activation of the ecdysone nuclear receptor, which may partly explain the endocrine disruption capability that has been previously suggested for this toxic metal. Our research adds to the growing evidence implicating heavy metals, and cadmium in particular, as potential endocrine disruptive agents and may have significant implications for ecological risk assessment of endocrine-disrupting compounds in invertebrates.

  14. Effect of sediment-associated pyrethroids, fipronil, and metabolites on Chironomus tentans growth rate, body mass, condition index, immobilization, and survival.

    Science.gov (United States)

    Maul, Jonathan D; Brennan, Amanda A; Harwood, Amanda D; Lydy, Michael J

    2008-12-01

    Pyrethroids and fipronil insecticides partition to sediment and organic matter in aquatic systems and may pose a risk to organisms that use these matrices. It has been suggested that bioavailability of sediment-sorbed pesticides is reduced, but data on toxicity of sediment-associated pesticides for pyrethroids and fipronil are limited. In the current study, 10-d sediment exposures were conducted with larval Chironomus tentans for bifenthrin, lambda-cyhalothrin, permethrin, fipronil, fipronil-sulfide, and fipronil-sulfone, the last two being common fipronil metabolites. Sublethal endpoints included immobilization, instantaneous growth rate (IGR), body condition index, and growth estimated by ash-free dry mass (AFDM). Pyrethroid lethal concentrations to 50% of the population (LC50s) were 6.2, 2.8, and 24.5 microg/g of organic carbon (OC) for bifenthrin, lambda-cyhalothrin, and permethrin, respectively; with the former two lower than previously published estimates. Fipronil, fipronil-sulfide, and fipronil-sulfone LC50 values were 0.13, 0.16, and 0.12 microg/g of OC, respectively. Ratios of LC50s to sublethal endpoints (immobilization, IGR, and AFDM) ranged from 0.90 to 9.03. The effects on growth observed in the present study are important because of the unique dipteran life cycle involving pupation and emergence events. Growth inhibition would likely lead to ecological impacts similar to mortality (no emergence and thus not reproductively viable) but at concentrations up to 4.3 times lower than the LC50 for some compounds. In addition, C. tentans was highly sensitive to fipronil and metabolites, suggesting that dipterans may be important for estimating risk and understanding effects of phenylpyrazole-class insecticides on benthic macroinvertebrate communities. PMID:18699702

  15. Effects of clay minerals and organic matter in formulated sediments on the bioavailability of sediment-associated uranium to the freshwater midge, Chironomus dilutus.

    Science.gov (United States)

    Crawford, Sarah E; Liber, Karsten

    2015-11-01

    It is well established that bioavailability influences metal toxicity in aquatic ecosystems. However, the factors and mechanisms that influence uranium (U) bioavailability and toxicity in sediment have not been thoroughly evaluated, despite evidence that suggests different sediment components can influence the sorption and interaction of some metals. Given that dissolved U is generally accepted as being the primary bioavailable fraction of U, it is hypothesized that adsorption and interaction of U with different sediment components will influence the bioavailability of U in sediment. We investigated the effects of key sediment physicochemical properties on the bioavailability of U to a model freshwater benthic invertebrate, Chironomus dilutus. Several 10-day spiked sediment bioaccumulation experiments were performed, exposing C. dilutus larvae to a variety of formulated sediments spiked with different concentrations of U (5, 50 and/or 200 mg U/kg d.w.). Mean accumulation of U in C. dilutus larvae decreased significantly from 1195 to 10 mg U/kg d.w. as kaolin clay content increased from 0% to 60% in sediment spiked with 50 mg U/kg d.w. Similarly, higher organic matter content also resulted in a significant reduction of U bioaccumulation in C. dilutus larvae, indicating a reduction in U bioavailability. Concentrations of U in both the overlying water and sediment pore water displayed a strong positive relationship to U bioaccumulation in C. dilutus larvae (r(2) = 0.77, p<0.001 and r(2) = 0.57, p < 0.001, respectively) for all experiments, while total U concentrations in the sediment had a poor relationship to U bioaccumulation (r(2) = 0.10, p = 0.028). Results from this research confirm that sediment clay and organic matter content play a significant role in altering U bioavailability, which is important in informing risk assessments of U contaminated sites and in the development of site-specific sediment quality guidelines for U.

  16. Effects of carbamazepine and two of its metabolites on the non-biting midge Chironomus riparius in a sediment full life cycle toxicity test.

    Science.gov (United States)

    Heye, Katharina; Becker, Dennis; Lütke Eversloh, Christian; Durmaz, Vedat; Ternes, Thomas A; Oetken, Matthias; Oehlmann, Jörg

    2016-07-01

    The antiepileptic drug carbamazepine (CBZ) and its main metabolites carbamazepine-10,11-epoxide (EP-CBZ) and 10,11-dihydro-10,11-dihydroxy-carbamazepine (DiOH-CBZ) were chosen as test substances to assess chronic toxicity on the non-biting midge Chironomus riparius. All the three substances were tested in a 40-day sediment full life cycle test (according to OECD 233) in which mortality, emergence, fertility, and clutch size were evaluated. In addition, these parameters were considered to calculate the population growth rate which represents an integrated measure to assess population relevant effects. With an LC50 of 0.20 mg/kg (time-weighted mean), the metabolite EP-CBZ was significantly more toxic than the parent substance CBZ (LC50: 1.1 mg/kg). Especially mortality, emergence, and fertility showed to be sensitive parameters under the exposure to CBZ and EP-CBZ. By using classical molecular dynamics (MD) simulations, the binding of CBZ to the ecdysone receptor was investigated as one possible mode of action (MoA) but appeared to be unlikely. The second metabolite DiOH-CBZ did not cause any effects within the tested concentration rage (0.17-1.2 mg/kg). Even though CBZ was less toxic compared to EP-CBZ, CBZ is found in the environment at much higher concentrations and therefore causes a higher potential risk for sediment dwelling organisms compared to its metabolites. Nevertheless, the current study illustrates the importance of including commonly found metabolites into the risk assessment of parent substances. PMID:27064208

  17. A multi-platform metabolomics approach demonstrates changes in energy metabolism and the transsulfuration pathway in Chironomus tepperi following exposure to zinc

    Energy Technology Data Exchange (ETDEWEB)

    Long, Sara M., E-mail: hoskins@unimelb.edu.au [Centre for Aquatic Pollution, Identification and Management (CAPIM), School of BioSciences, Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, 30 Flemington Road, Parkville, 3052 (Australia); Tull, Dedreia L., E-mail: dedreia@unimelb.edu.au [Metabolomics Australia, Bio21 Molecular Science and Biotechnology Institute, 30 Flemington Road, Parkville, 3052 (Australia); Jeppe, Katherine J., E-mail: k.jeppe@unimelb.edu.au [Centre for Aquatic Pollution, Identification and Management (CAPIM), School of BioSciences, Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, 30 Flemington Road, Parkville, 3052 (Australia); Centre for Aquatic Pollution, Identification and Management (CAPIM), School of BioSciences, The University of Melbourne, 3010 (Australia); De Souza, David P., E-mail: desouzad@unimelb.edu.au [Metabolomics Australia, Bio21 Molecular Science and Biotechnology Institute, 30 Flemington Road, Parkville, 3052 (Australia); Dayalan, Saravanan, E-mail: sdayalan@unimelb.edu.au [Metabolomics Australia, Bio21 Molecular Science and Biotechnology Institute, 30 Flemington Road, Parkville, 3052 (Australia); Pettigrove, Vincent J., E-mail: vpet@unimelb.edu.au [Centre for Aquatic Pollution, Identification and Management (CAPIM), School of BioSciences, The University of Melbourne, 3010 (Australia); McConville, Malcolm J., E-mail: malcolmm@unimelb.edu.au [Metabolomics Australia, Bio21 Molecular Science and Biotechnology Institute, 30 Flemington Road, Parkville, 3052 (Australia); Hoffmann, Ary A., E-mail: ary@unimelb.edu.au [Centre for Aquatic Pollution, Identification and Management (CAPIM), School of BioSciences, Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, 30 Flemington Road, Parkville, 3052 (Australia); School of BioSciences, Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, 30 Flemington Road, Parkville, 3052 (Australia)

    2015-05-15

    Highlights: • An integrated metabolomics approach was applied to examine zinc exposure in midges. • Changes in carbohydrate and energy metabolism were observed using GC–MS. • Transsulfuration pathway is affected by zinc exposure. • Heavy metals other than zinc affect the transsulfuration pathways differently. - Abstract: Measuring biological responses in resident biota is a commonly used approach to monitoring polluted habitats. The challenge is to choose sensitive and, ideally, stressor-specific endpoints that reflect the responses of the ecosystem. Metabolomics is a potentially useful approach for identifying sensitive and consistent responses since it provides a holistic view to understanding the effects of exposure to chemicals upon the physiological functioning of organisms. In this study, we exposed the aquatic non-biting midge, Chironomus tepperi, to two concentrations of zinc chloride and measured global changes in polar metabolite levels using an untargeted gas chromatography–mass spectrometry (GC–MS) analysis and a targeted liquid chromatography–mass spectrometry (LC–MS) analysis of amine-containing metabolites. These data were correlated with changes in the expression of a number of target genes. Zinc exposure resulted in a reduction in levels of intermediates in carbohydrate metabolism (i.e., glucose 6-phosphate, fructose 6-phosphate and disaccharides) and an increase in a number of TCA cycle intermediates. Zinc exposure also resulted in decreases in concentrations of the amine containing metabolites, lanthionine, methionine and cystathionine, and an increase in metallothionein gene expression. Methionine and cystathionine are intermediates in the transsulfuration pathway which is involved in the conversion of methionine to cysteine. These responses provide an understanding of the pathways affected by zinc toxicity, and how these effects are different to other heavy metals such as cadmium and copper. The use of complementary

  18. Effect of acute exposure to cadmium on the expression of heat-shock and hormone-nuclear receptor genes in the aquatic midge Chironomus riparius

    Energy Technology Data Exchange (ETDEWEB)

    Planello, R.; Martinez-Guitarte, J.L. [Grupo de Biologia y Toxicologia Ambiental, Facultad de Ciencias, Universidad Nacional de Educacion a Distancia, UNED, Senda del Rey 9, 28040 Madrid (Spain); Morcillo, G., E-mail: gmorcillo@ccia.uned.es [Grupo de Biologia y Toxicologia Ambiental, Facultad de Ciencias, Universidad Nacional de Educacion a Distancia, UNED, Senda del Rey 9, 28040 Madrid (Spain)

    2010-03-01

    Cadmium is a widespread and highly toxic pollutant of particular ecotoxicological relevance for aquatic ecosystems where it accumulates. To identify biomarkers for ecotoxicity monitoring, the effect of cadmium on the expression of different genes related to the stress response as well as to the ecdysone hormone-signalling pathway was studied in the aquatic larvae of Chironomus riparius (Diptera, Chironomidae), a standard test organism in aquatic toxicology testing. Reverse Transcription Polymerase Chain Reaction (RT-PCR) was used to evaluate the effects of acute and short-term cadmium exposures (10 mM CdCl{sub 2}, 12 h and 24 h) on the expression of hsp70, hsc70, hsp90 and hsp40 genes, as well as on that of the ecdysone hormonal-receptor genes (EcR and usp). A significant 3-fold increase in the level of hsp70 gene transcripts was induced by the treatment, whereas neither the other stress genes tested (hsp90 and hsp40) nor the constitutive form of hsp70, hsc70, was affected in the larvae exposed to cadmium. These results show that hsp70 is differentially activated to other environmentally regulated heat-shock genes, and constitutes a biomarker of exposure to this toxic metal. In addition, we also found that cadmium is able to alter the expression of the ecdysone receptor gene (EcR), whose mRNA level is significantly increased whereas usp levels remained unaltered. This finding, evidenced for the first time in invertebrates, supports the view that cadmium has the ability to mimic the effect of the hormone by the activation of the ecdysone nuclear receptor, which may partly explain the endocrine disruption capability that has been previously suggested for this toxic metal. Our research adds to the growing evidence implicating heavy metals, and cadmium in particular, as potential endocrine disruptive agents and may have significant implications for ecological risk assessment of endocrine-disrupting compounds in invertebrates.

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

    Science.gov (United States)

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

    2013-01-01

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

  20. Morphological deformities in Chironomus spp. (Diptera: Chironomidae) larvae as a tool for impact assessment of anthropogenic and environmental stresses on three rivers in the Juru river system, Penang, Malaysia.

    Science.gov (United States)

    Al-Shami, Salman; Rawi, Che Salmah M; Nor, Siti Azizah M; Ahmad, Abu Hassan; Ali, Arshad

    2010-02-01

    Morphological deformities in parts of the head capsule of Chironomus spp. larvae inhabiting three polluted rivers (Permatang Rawa [PRR], Pasir [PR], and Kilang Ubi [KUR]) in the Juru River Basin, northeastern peninsular Malaysia, were studied. Samples of the fourth-instar larvae at one location in each river were collected monthly from November 2007 to March 2008 and examined for deformities of the mentum, antenna, mandible, and epipharyngis. At each sample location, in situ measurements of water depth, river width, water pH, dissolved oxygen, and water temperature were made. Samples of river water and benthic sediments were also collected monthly from each larval sample location in each river and taken to the laboratory for appropriate analysis. Total suspended solids (TSSs), ammonium-N, nitrate-N, phosphate-P, chloride, sulfate, and aluminum content in water were analyzed. Total organic matter and nonresidual metals in the sediment samples were also analyzed. Among the three rivers, the highest mean deformity (47.17%) was recorded in larvae collected from KUR that received industrial discharges from surrounding garment and rubber factories, followed by PRR (33.71%) receiving primarily residues of fertilizers and pesticides from adjacent rice fields, and PR (30.34%) contaminated primarily by anthropogenic wastes from the surrounding residential areas. Among the various head capsule structures, deformity of the mentum was strongly reflective of environmental stress and amounted to 27.9, 20.87, and 30.19% in the PRR, PR, and KUR, respectively. Calculated Lenat's toxic score index satisfactorily explained the influence of prevailing environmental variables on the severity of mentum deformities. Redundancy analysis and forward selection selected TSSs, sediment Zn, Mn, Cu, and Ni, and water pH, dissolved oxygen, water temperature, total organic matter, nitrate-N, chloride, phosphate-P, ammonium-N, sulfate, and aluminum as parameters that significantly affected some

  1. Comparative effects of butyl benzyl phthalate (BBP) and di(2-ethylhexyl) phthalate (DEHP) on the aquatic larvae of Chironomus riparius based on gene expression assays related to the endocrine system, the stress response and ribosomes.

    Science.gov (United States)

    Planelló, Rosario; Herrero, Oscar; Martínez-Guitarte, José Luis; Morcillo, Gloria

    2011-09-01

    In this work, the effects of butyl benzyl phthalate (BBP) and di(2-ethylhexyl) phthalate (DEHP), two of the most extensively used phthalates, were studied in Chironomus riparius under acute short-term treatments, to compare their relative toxicities and identify genes sensitive to exposure. The ecotoxicity of these phthalates was assessed by analysis of the alterations in gene expression profiles of selected inducible and constitutive genes related to the endocrine system, the cellular stress response and the ribosomal machinery. Fourth instar larvae, a model system in aquatic toxicology, were experimentally exposed to five increasing concentrations (0.01, 0.1, 1, 10, and 100mg/L) of DEHP and BBP for 24h. Gene expression was analysed by the changes in levels of transcripts, using RT-PCR techniques with specific gene probes. The exposures to DEHP or BBP were able to rapidly induce the hsp70 gene in a concentration-dependent manner, whereas the cognate form hsc70 was not altered by either of these chemicals. Transcription of ribosomal RNA as a measure of cell viability, quantified by the levels of ITS2, was not affected by DEHP, but was slightly, yet significantly, downregulated by BBP at the highest concentrations tested. Finally, as these phthalates are classified as endocrine disruptor chemicals (EDCs), their potential effect on the ecdysone endocrine system was studied by analysing the two genes, EcR and usp, of the heterodimeric ecdysone receptor complex. It was found that BBP provoked the overexpression of the EcR gene, with significant increases from exposures of 0.1mg/L and above, while DEHP significantly decreased the activity of this gene at the highest concentration. These data are relevant as they show for the first time the ability of phthalates to interfere with endocrine marker genes in invertebrates, demonstrating their potential capacity to alter the ecdysone signalling pathway. Overall, the study clearly shows a differential gene-toxin interaction

  2. A field study of the socio-ecology of the Goeldi's monkey (Callimico goeldii) in northern Bolivia.

    Science.gov (United States)

    Pook, A G; Pook, G

    1981-01-01

    A 5-month field study on both the distribution and ecology of Callimico goeldii was carried out in the seasonally dry rain forest of north-western Bolivia. The species was found to be very sparsely distributed (approximately one group per 4 km2) in isolated groups of about 6 animals throughout the study area. Callimico was found to associate a great deal with two species of Saguinus that inhabit the same region in greater densities. It appears to be a habitat specialist, preferring low-lying and damp, but well-drained, bamboo forest and spending nearly all its time within 3 m of ground level, travelling mainly by vertical clinging and leaping. We believe that this ecological specialisation accounts for the species' discontinuous micro-distribution, and that this in turn is related to Callimico's distinctive pattern of social organisation. PMID:6792016

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

    Science.gov (United States)

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

    2014-01-01

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

  4. Evaluación del riesgo ambiental de carbofurano en bioensayos con organismos no blanco

    Directory of Open Access Journals (Sweden)

    José Alberto Iannacone

    2011-06-01

    Full Text Available El carbofurano es uno de los plaguicidas más empleado en la agricultura peruana. El objetivo de este trabajo fue evaluar el riesgo ambiental del carbofurano en bioensayos de toxicidad, sobre once especies no destinatarias. La siguiente secuencia relativa de mayor a menor cocientes de riesgo (CR del carbofurano para los 19 puntos finales de efecto en once especies fue encontrada: Daphnia magna (mortalidad > Lemna minor (inhibición de formación de las hojas > Paracheirodon innesi (nado extraño = P. innesi (incremento del movimiento opercular > Chironomus calligraphus (mortalidad > L. minor (necrosis > P. innesi (mortalidad > L. minor (clorosis > Tetrapygus niger (inhibición de la fecundación > Coturnix japonica (mortalidad > Oncorhynchus mykiss (incremento de coloración > Ceraeochrysa cincta (no eclosión de huevos > O. mykiss (mortalidad con oxígeno > O. mykiss (mortalidad sin oxígeno > Trichogramma pretiosum (mortalidad > C. cincta (mortalidad > T. pretiosum (no emergencia de adultos > Trichogramma pintoi (mortalidad > Beauveria bassiana (inhibición del crecimiento. Los cocientes de riesgo (CR indicaron en todos los casos un alto riesgo del carbofurano principalmente en el ambiente acuático en comparación con el terrestre.Carbofuran is one of the most employed pesticides in Peruvian agriculture. This research aimed to evaluate the risk assessment in bioassays of carbofuran on eleven non-target species. The following relative sequence in decreasing ecotoxicity order in terms of RQ (Risk quotient to carbofuran to 19 end points on 11 species was found: Daphnia magna (mortality > Lemna minor (inhibition of new fronds > Paracheirodon innesi (strange swim = P. innesi (increase of opercula movement > Chironomus calligraphus (mortality > L. minor (necrosis > P. innesi (mortality > L. minor (chlorosis > Tetrapygus niger (inhibition of fertilization> Coturnix japonica (mortality > Oncorhynchus mykiss (increase of coloration > Ceraeochrysa

  5. Da 'abominável profissão de vampiros': Emílio Goeldi e Os mosquitos no Pará (1905) On 'the abominable profession of being a vampire': Emílio Goeldi and Mosquitos in Pará (1905)

    OpenAIRE

    Nelson Sanjad

    2003-01-01

    Nas áreas de saúde pública e de entomologia, a virada do século XX caracterizou-se sobretudo pelo destaque dado aos insetos como transmissores de doenças. Médicos, bacteriologistas e zoólogos dedicaram-se com afinco à tentativa de compreender melhor a etiologia de doenças como malária e febre amarela, assim como inventariar as espécies de insetos associadas à doenças, estudar sua classificação científica e biologia e estabelecer procedimentos que permitissem controlar as epidemias. O zoólogo ...

  6. Ecotoxicological assessment of grey water treatment systems with Daphnia magna and Chironomus riparius

    NARCIS (Netherlands)

    L. Hernádez Leal; A.M. Soeter; S.A.E. Kools; M.H.S. Kraak; J.R. Parsons; H. Temmink; G. Zeeman; C.J.N. Buisman

    2012-01-01

    In order to meet environmental quality criteria, grey water was treated in four different ways: 1) aerobic 2) anaerobic + aerobic 3) aerobic + activated carbon 4) aerobic + ozone. Since each treatment has its own specific advantages and disadvantages, the aim of this study was to compare the ecotoxi

  7. Bioconcentration and acute toxicity of polycyclic musks in two benthic organisms (Chironomus riparius and Lumbriculus variegatus)

    NARCIS (Netherlands)

    Artola-Garicano, E.; Sinnige, T.L.; Holsteijn, I. van; Vaes, W.H.J.; Hermens, J.L.M.

    2003-01-01

    In the current study, the bioconcentration behavior and acute toxicity of two polycyclic musks, Tonalide® 7-acetyl-1,1,3,4,4,6,-hexamethyl-1,2,3,4,-tetrahydronaphthalene (AHTN) and Galaxolide® 1,3,4,6,7,8-hexahydro-4,6,6,7,8,8-hexa-methyl-cyclopenta[γ]-2- benzopyran (HHCB), were studied in two benth

  8. Determination of larval instars in Chironomus sancticaroli (Diptera: Chironomidae) using novel head capsule structures

    OpenAIRE

    Vinicius S. Richardi; Débora Rebechi; José M. R. Aranha; Mário A. Navarro-Silva

    2013-01-01

    Determining the age composition of a population is important when conducting ecological, taxonomic and environmental assessments. Morphometric measurements of the head capsule, especially the length and width, are widely used in the identification of insect instars, but alternative ways for determining the age of insects can expand the options for the analysis of field and laboratory populations. This study evaluated the morphometry of the antennae, mandibles, mentum and ventromental plates t...

  9. Combined effects of Cu and UVR on survival and melanin synthesis in Chironomus riparius larvae

    NARCIS (Netherlands)

    M.L. de Baat; M. van Gemert; R.A. Verweij; R.A. Loayza Muro; M.H.S. Kraak

    2012-01-01

    The tropical Andes encompass vast areas with altitudes above 4000 m, where the combination of high UV radiation and metal pollution creates environments that challenge the survival and persistence of aquatic life. Since the pigment melanin counteracts the negative effects of UVR, and has the additio

  10. Combined effects of Cu and UVR on survival and melanin synthesis in Chironomus riparius larvae

    OpenAIRE

    Baat, de, M.L.; Gemert, van, F.H.M.; Verweij, R.A.; Loayza Muro, R.A.; Kraak, M.H.S.

    2012-01-01

    The tropical Andes encompass vast areas with altitudes above 4000 m, where the combination of high UV radiation and metal pollution creates environments that challenge the survival and persistence of aquatic life. Since the pigment melanin counteracts the negative effects of UVR, and has the additional ability to sequester metal cations, it has been hypothesized that melanin plays an important role in the ability of benthic invertebrates to persist under these harsh conditions. The aim of the...

  11. Toxicity of Sediment-Associated Pesticides to Chironomus dilutus and Hyalella azteca

    OpenAIRE

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

    2010-01-01

    Two hundred sediment samples were collected and their toxicity evaluated to aquatic species in a previous study in the agriculturally dominated Central Valley of California, United States. Pyrethroid insecticides were the main contributors to the observed toxicity. However, mortality in approximately one third of the toxic samples could not be explained solely by the presence of pyrethroids in the matrices. Hundreds of pesticides are currently used in the Central Valley of California, but onl...

  12. The mystery of the Gouldian birds: an ornithological detective story

    NARCIS (Netherlands)

    Güntert, M.; Steinheimer, F.D.; Gessner, S.

    2005-01-01

    While compiling a computer database of the avian specimens of the E.A. Goeldi collection a considerable number of skins with original labels from John Gould were discovered. In an earlier inventory they had been registered as part of the Goeldi collection, but as there was no apparent connection wit

  13. Control of nitrous oxide emission from Chironomus plumosus larvae by nitrate and temperatur

    DEFF Research Database (Denmark)

    Stief, Peter; Polerecky, Lubos; Poulsen, Morten;

    2010-01-01

    , and N2O uptake was never observed. For both types of larvae, the rate of N2O emission was stimulated by temperature (when the NO3- concentration in the water column was higher than 25–50 µmol L-1) and by NO3- (when the temperature was higher than 4–10°C). Modeling based on experimentally determined...

  14. Chronic effects of Cd on the reproduction of the guppy (Poecilia reticulata) through Cd-accumulated midge larvae (Chironomus yoshimatsui)

    Energy Technology Data Exchange (ETDEWEB)

    Hatakeyama, S.; Yasuno, M.

    1987-12-01

    Chronic effects of Cd on the growth and reproduction of the guppy (Poecilia reticulata) were studied using a food chain model, midge larvae as prey and guppy as predator. The transfer rate of Cd from the midge to the guppy was between 0.5 and 1% during the 30-day experiment. Growth rate of the guppy fed Cd-accumulated midge larvae (270 micrograms/g dry wt) for 30 days was not impaired. Cumulative numbers of fry produced by the guppy fed Cd-accumulated midge larvae (210 micrograms/g) for 2 months decreased to ca. 80% of the control. Guppies had been fed the Cd-accumulated midges from 30 days old for 7 months. Cumulative numbers of fry produced by the guppy fed midge larvae-accumulated 500, 800, and 1300 micrograms Cd/g for 6 months decreased to 79, 65, and 55% of the control, respectively. Similar effects of Cd on the reproduction of guppy were shown between the guppies fed the Cd-accumulated midge larvae (500 micrograms Cd/g) and exposed to 10 or 20 micrograms Cd/liter for the 6 months. The Cd concentrations of the digestive tract, liver, and kidney increased strongly, indicating that such Cd accumulation was brought on mainly through the Cd-accumulated midges. Mortality of the female guppies fed larvae-accumulated 1300 micrograms Cd/g increased abruptly from the 6 months of the experiment, whereas no male guppy died during the experiment.

  15. Two new biting midges from Pará, Brazil (Diptera: Ceratopogonidae

    Directory of Open Access Journals (Sweden)

    Rosimeire Lopes da Trindade

    2011-02-01

    Full Text Available Two new species of Culicoides Latreille of the subgenus Haematomyidium Goeldi are described and illustrated based on female specimens from Pará, Brazil. The new species are compared with their similar congeners.

  16. Dicty_cDB: Contig-U04308-1 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available e) Klebsiella pneumoniae 342 plasmid... 35 2.2 AF036897_1( AF036897 |pid:none) Chironomus pallidivittatus... special... 35 2.2 AF036896_1( AF036896 |pid:none) Chironomus pallidivittatus specia

  17. Comments on some species in Chironomini

    OpenAIRE

    Henk Vallenduuk

    2013-01-01

    Re-identification of some Chironomus species, Chironomus macani and C. dorsalis. Comments on information in Moller Pillot, 2009. A short discussion on the value of single reared larvae, cytology and DNA.

  18. Biological responses of midge (Chironomus riparius) and lamprey (Lampetra fluviatilis) larvae in ecotoxicity assessment of PCDD/F-, PCB- and Hg-contaminated river sediments.

    Science.gov (United States)

    Salmelin, J; Karjalainen, A K; Hämäläinen, H; Leppänen, M T; Kiviranta, H; Kukkonen, J V K; Vuori, K M

    2016-09-01

    We evaluated the utility of chironomid and lamprey larval responses in ecotoxicity assessment of polychlorinated dibenzo-p-dioxins, dibenzofurans (PCDD/F)-, polychlorinated biphenyls (PCB)- and mercury (Hg)-contaminated river sediments. Sediment samples were collected from the River Kymijoki with a known industrial pollution gradient. Sediment for the controls and lamprey larvae were obtained from an uncontaminated river nearby. Contamination levels were verified with sediment and tissue PCDD/F, PCB and Hg analyses. Behaviour of sediment-exposed chironomid and lamprey larvae were measured with Multispecies Freshwater Biomonitor© utilizing quadrupole impedance conversion technique. In addition, mortality, growth and head capsule deformity incidence of chironomids were used as ecotoxicity indicators. WHOPCDD/F+PCB-TEQ in the R. Kymijoki sediments ranged from the highest upstream 22.36 ng g(-1) dw to the lowest 1.50 ng g(-1) near the river mouth. The sum of PCDD/Fs and PCBs correlated strongly with Hg sediment concentrations, which ranged from contaminated sediments and was negatively related to sediment ∑PCDD/Fs, WHOPCDD/F+PCB-TEQ and Hg. There were no significant differences in larval mortality or chironomid mentum deformity incidence between the sediment exposures. The distinct behavioural patterns of both species indicate overall applicability of behavioural MFB measurements of these species in sediment toxicity bioassays. Chironomids spent less and lampreys more time in locomotion in the most contaminated sediment compared to the reference, albeit statistically significant differences were not detected. Lamprey larvae had also a greater activity range in some of the contaminated sediments than in the reference. High pollutant levels in lamprey indicate risks for biomagnification in the food webs, with potential health risks to humans consuming fish.

  19. Toxicity of bed sediments from the Niagara River Area of Concern and tributaries, New York, to Chironomus dilutus and Hyalella azteca, 2014-15

    Science.gov (United States)

    George, Scott D.; Baldigo, Barry P.; Duffy, Brian T.

    2016-09-20

    The Niagara River was designated as an Area of Concern in 1987 on both the United States and Canadian sides of the international boundary line because past industrial discharges and hazardous waste sites had caused extensive degradation of aquatic habitats. The degradation of the “benthos”, or the benthic macroinvertebrate community, was identified as one of seven beneficial use impairments caused by contaminated bed sediments. The U.S. Geological Survey and the New York State Department of Environmental Conservation, in cooperation with the U.S. Environmental Protection Agency, conducted a study in 2014 and 2015 to gather more extensive data on (a) the toxicity of bed sediments and (b) the status of macroinvertebrate communities on the main stem and tributaries of the Niagara River. This report addresses the first component of that study (toxicity of bed sediments), and summarizes results from laboratory toxicity tests that compare the survival and growth of two macroinvertebrate species between bed sediments from study sites and laboratory controls. Sediment toxicity was negligible at most sites, however poor performance of one or both test species in bed sediments from several tributary sites suggests that the quality of sediments may be adversely affecting benthic macroinvertebrate communities in some tributaries to the Niagara River.

  20. Dicty_cDB: Contig-U15735-1 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available ' ... 103 7e-57 8 ( AF448434 ) Chironomus yoshimatsui heat shock cognate 70 gene... 70 2e-56 12 ( DQ898163 )...lotes nobilii heat shock protei... 558 e-157 AB162946_1( AB162946 |pid:none) Chironomus yoshimatsui HSP70 mR

  1. Simulium argentiscutum sp. nov. (Diptera: simuliidae, a member of the S. amazonicum-group of species; description of adults, pupa and larva Simulium argentiscutum sp. nov. (Diptera: simuliidae, um membro do grupo de espécies S. amazonicum: descrição dos adultos, pupa e larva

    Directory of Open Access Journals (Sweden)

    Anthony John Shelley

    1980-12-01

    Full Text Available The adult, pupal and larval morphology of S. argentiscutum sp. nov., a member of the S. amazonicum-group, is compared with S. amazonicum Goeldi and its distribution, biology and medical importance are discussed. S. argentiscutum is one the most important anthropophilic species in the S. amazonicum-group as it is responsible, together with S. amazonicum, for the transmission of Mansonella ozzardi in Brazil.A morfologia dos adultos e da pupa e larva do S. argentiscutum sp. nov., um membro do grupo de espécies S. amazonicum, é comparada com a do S. amazonicum Goeldi e são discutidos da sua distribuição, biologia e importância médica. S. argentiscutum é uma das espécies antropofílicas mais importantes do grupo amazonicum porque é responsável, junto com o S. amazonicum, pela transmissão da mansonelose no Brasil.

  2. Molecular evidence of facultative intraguild predation by Monochamus titillator larvae (Coleoptera: Cerambycidae) on members of the southern pine beetle guild

    Science.gov (United States)

    Schoeller, Erich N.; Husseneder, Claudia; Allison, Jeremy D.

    2012-11-01

    The southern pine bark beetle guild (SPBG) is arguably the most destructive group of forest insects in the southeastern USA. This guild contains five species of bark beetles (Coleoptera: Curculionidae: Scolytinae): Dendroctonus frontalis, Dendroctonus terebrans, Ips avulsus, Ips calligraphus, and Ips grandicollis. A diverse community of illicit receivers is attracted to pheromones emitted by the SPBG, including the woodborers Monochamus carolinensis and Monochamus titillator (Coleoptera: Cerambycidae). These woodborers have been traditionally classified as resource competitors; however, laboratory assays suggest that larval M. carolinensis may be facultative intraguild predators of SPBG larvae. This study used polymerase chain reaction (PCR)-based molecular gut content analyses to characterize subcortical interactions between M. titillator and members of the SPBG. The half-lives of SPBG DNA were estimated in the laboratory prior to examining these interactions in the field. A total of 271 field-collected M. titillator larvae were analyzed and 26 (9.6 %) tested positive for DNA of members of the SPBG. Of these larvae, 25 (96.2 %) tested positive for I. grandicollis and one (3.8 %) for I. calligraphus. Failure to detect D. terebrans and D. frontalis was likely due to their absence in the field. I. avulsus was present, but primers developed using adult tissues failed to amplify larval tissue. Results from this study support the hypothesis that larval Monochamus spp. are facultative intraguild predators of bark beetle larvae. Additionally, this study demonstrates the capabilities of PCR in elucidating the interactions of cryptic forest insects and provides a tool to better understand mechanisms driving southern pine beetle guild population fluctuations.

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

    Science.gov (United States)

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

  4. Emilia Snethlage (1868-1929): uma naturalista alemã na Amazônia Emília Snethlage (1868-1929): a german naturalist in the Amazon

    OpenAIRE

    Miriam Junghans

    2008-01-01

    A ornitóloga alemã Emilia Snethlage (1868-1929) desenvolveu sua carreira científica no Brasil, trabalhando no Museu Paraense Emilio Goeldi e no Museu Nacional do Rio de Janeiro. Um dos pontos altos da sua obra científica foi o "Catálogo das aves amazônicas", publicado em 1914. Outro foi a travessia que realizou a pé, acompanhada apenas por guias índios, entre os rios Xingu e Tapajós, em 1909, percorrendo um território até então desconhecido. A historiografia das ciências no Brasil apresenta, ...

  5. Acanthocephala Larvae parasitizing Ameiva ameiva ameiva (Linnaeus, 1758 (Squamata: Teiidae

    Directory of Open Access Journals (Sweden)

    Lilian Cristina Macedo

    2016-03-01

    Full Text Available Abstract Knowledge concerning the taxonomy and biology of species of Acanthocephala, helminth parasites of the helminth species of the phylum Acanthocephala, parasites of lizards in Brazilian Amazonia, is still insufficient, but reports of Acanthocephala in reptiles are becoming increasingly common in the literature. Cystacanth-stage Acanthocephalan larvae have been found in the visceral peritoneum during necropsy of Ameiva ameiva ameivalizards from the “Osvaldo Rodrigues da Cunha” Herpetology Collection of the Emílio Goeldi Museum, Belém, Pará, Brazil. The aim of this study was to present the morphological study of the Acanthocephala larvae found in A. ameiva ameiva lizard.

  6. LIFE CYCLE AND PRODUCTION OF CHIRONOMIDAE(DIPTERA) IN BIANDANTANG, A TYPICAL MACROPHYTIC LAKE (HUBEI, CHINA)

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The life cycle and annual production of four dominant species of Chironomids (Chironomus plumosus, Chironomus sp., Clinotanypus sp., Tokunagayusurika akamusi) were studied with samples taken monthly in Biandantang Lake at eight stations from April, 1996 to March, 1997. Instar-frequency data showed C. plumosus was univoltine, while the other three were bivoltine. Production in wet weight (g/(m2.a)) calculated by the size-frequency method for each species were: C. plumosus, 2.663; Chironomus sp.,1.161 ;Clinotanypus sp., 0.270; T. akamusi, 1.476. Based on the mean standing stock, their P/B ratios were 3.2, 4.0, 6.2 and 4.4, respectively.

  7. Scanning electron microscopy of the antennal sensilla in female Culicoides paraensis (Diptera: Ceratopogonidae Microscopia eletrônica de varredura das sensilas antenais em fêmeas de Culicoides paraensis (Diptera: Ceratopogonidae

    Directory of Open Access Journals (Sweden)

    M. L. Felippe-Bauer

    1989-12-01

    Full Text Available We studied by sanning electron microscopy the number, types, structure and distribution of the antennal sensilla of the medical important ceratopogonid Culicoides paraensis (Goeldi. There are about 174 sense organs on the antenmal flagellum which are classified as sensilla chaetica; sharp-tipped and blunt-tipped (type I and II sensilla trichodea; sensilla basiconica; sensilla coeloconica; sensilla ampullacea and styloconic-type sensilla. The role of antennal sensory organs are discussed regarding the host preference of the biting midges.Estudos sobre o número, tipo, estrutura e distribuição das sensilas antenais do ceratopogonídeo de importância médica, Culicoides paraensis (Goeldi, são realizados com microscopia eletrônica de varredura. Encontram-se aproximadamente 174 órgãos sensoriais no flagelo, os quais são classificados em sensila caética; sensila trichoidea, de ápice afilado e de ápice curvo (tipoI e II; sensila basicônica; sensila ampulácea e sensila do tipo estilocônica. É discutido o papel dos órgãos sensoriais da antena na relação Culicoides/hospedeiro.

  8. A simple protocol for the extraction and sequence analysis of DNA from study skin of museum collections

    Directory of Open Access Journals (Sweden)

    Nadia de Moraes-Barros

    2007-01-01

    Full Text Available Museum collections have been widely used as sources of biological samples for molecular biology studies and there are several methodologies and techniques to obtain and analyze DNA from tissues archived in museums, but most of these protocols have been developed for a specific tissue or are commercial kits. We present a simple protocol for extracting and amplifying DNA segments from sloth museum specimens. With this simple protocol we analyzed DNA fragments from 64% of 64 skin samples from three-toed sloths (Bradypus variegatus and Bradypus tridactylus archived in three different museums: 43 samples from the University of São Paulo Museum of Zoology (Museu de Zoologia da Universidade de São Paulo, MUZUSP São Paulo, São Paulo, Brazil; 18 samples from the Emílio Goeldi Museum (Museu Paraense Emílio Goeldi, MPEG, Belém, Pará, Brazil; and 3 samples from the Museum of Vertebrate Zoology (MVZ University of California, Berkeley, USA. The specimens sampled ranged in age from 18 to 108 years old. Our methodology allowed the recovery of up to 700 bp of mitochondrial DNA and 400 bp of nuclear genes. Thereafter, it is useful for genetic diversity studies of three-toed sloths and could be applied to other animals.

  9. Purificação do flavonóide trans-tilirosídeo do extrato metanólico das folhas de Gochnatia barrosii Cabrera (asteraceae e avaliação da sua atividade nematicida Purification of the flavonoid trans-tiliroside from the methanolic extract of Gochnatia barrosii Cabrera (Asteraceae leaves and evaluation of the nematicidal activity

    Directory of Open Access Journals (Sweden)

    Helvécio Martins dos Santos Júnior

    2010-10-01

    Full Text Available O fracionamento do extrato metanólico das folhas de Gochnatia barrosii Cabrera (Asteraceae resultou no isolamento do flavonol glicosídico trans-tilirosídeo [kaempferol 3-O- -D-(6''-O-E-p-cumaroil-glicopiranosídeo], que nunca tinha sido identificado na referida espécie vegetal. Em teste realizado in vitro, observou-se que tal substância a 500 μg/mL, não tem efeito sobre a mortalidade de juvenis do segundo estágio do nematóide Meloidogyne exigua Goeldi.Fractionation of the methanolic extract from Gochnatia barrosii Cabrera (Asteraceae leaves resulted in the isolation of the flavonol glycoside trans-tiliroside [kaempferol 3-O- -D-(6''-O-E-p-coumaroyl-glucopyranoside], which had never been found in such plant species. Such substance at 500 μg/mL caused no in vitro effect on the mortality of second-stage juveniles of the nematode Meloidogyne exigua Goeldi.

  10. The effects of bioturbation on nutrient fluxes in lakes subjected to lake restoration

    DEFF Research Database (Denmark)

    Kristensen, Thomas Boll; Reitzel, Kasper; Andersen, Frede Østergaard;

    ) and cores from areas with and areas without an Al layer in Lake Nordborg with benthic macroinvertebrates in natural densities and "natural densities + 2800 Chironomus plumosus m-2" we are investigating the effects of benthic macroinvertebrates on nutrient fluxes and their influence on the effectiveness...

  11. Habitat selection by chironomid larvae: fast growth requires fast food

    NARCIS (Netherlands)

    Haas, de E.M.; Wagner, C.; Koelmans, A.A.; Kraak, M.H.S.; Admiraal, W.

    2006-01-01

    1. Sediments have been considered as a habitat, a cover from predators and a source of food, but also as a source of potential toxic compounds. Therefore, the choice of a suitable substrate is essential for the development of chironomids. 2. For the midge Chironomus riparius (Meigen 1804) the growth

  12. Ocorrências da família Sarcophagidae (Insecta, Díptera) em carcaças de Sus scrofa Linnaeus (Suidae) em Belém-PA, colonização da carcaça e sua relação com o tempo de morte do animal

    OpenAIRE

    Paula Daniela Raiol Bitar de Araujo; Thaissa Fernandes da Silva Rodrigues; Gustavo Caminoto Geiser

    2013-01-01

    O presente trabalho visa verificar a ocorrência de Dípteros de interesse forense em uma carcaça de suíno, sua colonização e relação com o tempo de morte do animal, dando maior ênfase na família Sarcophagidae, por constituírem fauna constante e obrigatória de carcaça e por utilizarem esse substrato como sítio de procriação. O experimento foi realizado em uma área de mata, localizada nas dependências do Instituto de Pesquisa Museu Emílio Goeldi, em Belém-Pa. Foi utilizado como isca um suíno (Su...

  13. Aggressive keloid-mimicking tumor in Melanosuchus niger in captivity

    Directory of Open Access Journals (Sweden)

    Washington Luiz Assunção Pereira

    2013-07-01

    Full Text Available The objective of this note is to describe a case of exuberant scarring formation, with keloid characteristics and pseudo-tumoral configuration in a male Black caiman (Melanosuchus niger, with an estimated age of 60 years, belonging to the Zoobotanical Park at the Emílio Goeldi Museum, located in Belém, Pará, Brazil. The alteration appeared on the right posterior limb involving two distal phalanges of the lateral digit and measured 12.4cm at the greatest width. The keloid tissue was surgically removed and samples were processed and analyzed histopathologically, revealing growth made up of fibrous connective tissue with the habitual morphology, which was structurally mature in the more central areas.

  14. Early larval development in the laboratory of Alpheus estuariensis (Crustacea: Caridea from the Amazon Region Os estágios iniciais de Alpheus estuariensis (Crustacea: Caridea da Região Amazônica, cultivado em laboratório

    Directory of Open Access Journals (Sweden)

    Marcus A. B. Pires

    2008-06-01

    Full Text Available Here we describe and illustrate in detail four early zoeal stages of Alpheus estuariensis Christoffersen, 1984 from larvae reared in the laboratory. Two ovigerous females were collected in the tidal creek of the Bragança estuary, state of Pará, northeastern Brazil. After hatching, the larvae were placed in small containers (with 10 larvae in each. Females were deposited in the Museu Paraense Emilio Goeldi (MPEG 0803 and the larvae of each larval stage in the Zoological Museum of São Paulo University (MUSP18452. Ten larvae and exuviae were dissected with fine needles under an ocular microscope. Morphological comparisons with previous studies on larval development of the Alpheus species are briefly discussed.O presente estudo descreve e ilustra em detalhes os quatro primeiros estágios de Alpheus estuariensis Christoffersen, 1984 a partir de larvas cultivadas em laboratório. Duas fêmeas ovígeras foram coletadas no canal de maré do estuário de Bragança, estado do Pará, nordeste do Brasil. Após a eclosão, as larvas foram colocadas em pequenos recipientes (com 10 larvas em cada. As fêmeas foram depositadas no Museu Paraense Emilio Goeldi (MPEG 0803 e as larvas de cada estágio larval no Museu zoológico da Universidade de São Paulo (MUSP18452. Foram dissecadas 10 larvas e exúvias com finas agulhas sob um microscópio ocular. Comparações morfológicas com outros estudos reportados sobre o desenvolvimento larval de espécies de Alpheus são brevemente discutidas.

  15. The Parthenogenetic Cosmopolitan Chironomid, Paratanytarsus grimmii, as a New Standard Test Species for Ecotoxicology: Culturing Methodology and Sensitivity to Aqueous Pollutants.

    Science.gov (United States)

    Gagliardi, Bryant S; Long, Sara M; Pettigrove, Vincent J; Hoffmann, Ary A

    2015-09-01

    Chironomids from the genus Chironomus are widely used in laboratory ecotoxicology, but are prone to inbreeding depression, which can compromise test results. The standard Chironomus test species (C. riparius, C. dilutus and C. yoshimatsui) are also not cosmopolitan, making it difficult to compare results between geographic regions. In contrast, the chironomid Paratanytarsus grimmii is cosmopolitan, and not susceptible to inbreeding depression because it reproduces asexually by apomictic parthenogenesis. However, there is no standardised culturing methodology for P. grimmii, and a lack of acute toxicity data for common pollutants (metals and pesticides). In this study, we developed a reliable culturing methodology for P. grimmii. We also determined 24-h first instar LC50s for the metals Cu, Pb, Zn, Cd and the insecticide imidacloprid. By developing this culturing methodology and generating the first acute metal and imidacloprid LC50s for P. grimmii, we provide a basis for using P. grimmii in routine ecotoxicological testing.

  16. Avaliação ecológica da qualidade da água utilizando ensaios in situ com C. riparius

    OpenAIRE

    Faria, Ana Mafalda Sá de

    2005-01-01

    This thesis deals with the use of in situ bioassays with Chironomus riparius larvae to assess water quality and the risk of contaminants on freshwater ecosystems. These bioassays were seasonally deployed in selected sites on contaminated and reference rivers of North and Central Portugal, to evaluate their performance in assessing water quality in lotic ecosystems. Several biological responses (development, growth, survival and post-exposure feeding rate) were determined and the biotic, ph...

  17. Seasonal variation in the diet of Redshank Tringa totanus in the Odiel Marshes, southwest Spain: a comparison of faecal and pellet analysis

    OpenAIRE

    Sánchez, Marta I; Green, Andy J.; Castellanos, Eloy M.

    2005-01-01

    Aims To assess seasonal variation in Redshank diet at a major passage site, and to compare data derived from analysing pellets or faeces. Methods At the Odiel Marshes in 2001, pellets from spring migration (39), autumn migration (121) and midwinter (15) were analysed, together with faecal samples from autumn (84). Results The abundance of different invertebrate groups in pellets varied between seasons. In spring, Chironomus salinarius pupae and larvae dominated by volume, followed by ...

  18. Deriving Freshwater Quality Criteria for Iron, Lead, Nickel, and Zinc for Protection of Aquatic Life in Malaysia

    OpenAIRE

    Shuhaimi-Othman, M.; Y. Nadzifah; Nur-Amalina, R.; Umirah, N. S.

    2012-01-01

    Freshwater quality criteria for iron (Fe), lead (Pb), nickel (Ni), and zinc (Zn) were developed with particular reference to aquatic biota in Malaysia, and based on USEPA's guidelines. Acute toxicity tests were performed on eight different freshwater domestic species in Malaysia which were Macrobrachium lanchesteri (prawn), two fish: Poecilia reticulata and Rasbora sumatrana, Melanoides tuberculata (snail), Stenocypris major (ostracod), Chironomus javanus (midge larvae), Nais elinguis (anneli...

  19. Consequences of Physical Disturbance by Tadpoles and Snails on Chironomid Larvae

    OpenAIRE

    Gargi Pal; Gautam Aditya; Niladri Hazra

    2014-01-01

    Indirect interactions among community members impact on organisms. The effects of two snails, banded pond snail, Bellamya bengalensis (Lamarck), and Red-rimmed melania, Melanoides tuberculata (Müller), and tadpoles of Asian common toad, Duttaphrynus melanostictus (Schneider), on nonbiting midge larvae, Chironomus striatipennis Kieffer, were observed in experimental microcosm. Decrease in tube number and tube length of midge larvae was observed compared to control condition due to introduction...

  20. Invertebrate communities of Nabugabo Lakes: a vital support resource for the fisheries and ecosystem diversity

    OpenAIRE

    Ndawula, L.M.; Kiggundu, V.; Pabire Ghandi, W.

    2005-01-01

    A field study of the invertebrate communities of the Nabugabo lakes(Nabugabo,Kayanja and Kayugi)showed the occurrence of copepoda, cladocera and rotifera(micro-invertebrates or zooplankton); Ephemeroptera and Diptera(macro-invertebrates or zoo-benthos). The most commonly encountered taxa were thermocyclops neglectus, moinamicrura,several rotiferan species(micro-invertebrates);P.adusta,chironomus, tanipodinae and trichoptera(macro- invertebrates). These organisms are assumed to be readily avai...

  1. Genomic basis of ecological niche divergence among cryptic sister species of non-biting midges

    OpenAIRE

    Schmidt, Hanno; Greshake, Bastian; Feldmeyer, Barbara; Hankeln, Thomas; Pfenninger, Markus

    2013-01-01

    Background: There is a lack of understanding the evolutionary forces driving niche segregation of closely related organisms. In addition, pinpointing the genes driving ecological divergence is a key goal in molecular ecology. Here, larval transcriptome sequences obtained by next-generation-sequencing are used to address these issues in a morphologically cryptic sister species pair of non-biting midges (Chironomus riparius and C. piger). Results: More than eight thousand orthologous open re...

  2. An Asiatic Chironomid in Brazil: morphology, DNA barcode and bionomics

    OpenAIRE

    Gizelle Amora; Neusa Hamada; Lívia Maria Fusari; Vanderly Andrade-Souza

    2015-01-01

    Abstract In most freshwater ecosystems, aquatic insects are dominant in terms of diversity; however, there is a disproportionately low number of records of alien species when compared to other freshwater organisms. The Chironomidae is one aquatic insect family that includes some examples of alien species around the world. During a study on aquatic insects in Amazonas state (Brazil), we collected specimens of Chironomidae that are similar, at the morphological level, to Chironomus kiiensis Tok...

  3. Extracellular electrical activity from the photoreceptors of midge

    Indian Academy of Sciences (India)

    A A Babrekar; G R Kulkarni; B B Nath; P B Vidyasagar

    2004-09-01

    The ontogeny of photosensitivity has been studied in a holometabolous insect, the midge Chironomus ramosus. The life cycle of midges shifts from an aquatic environment to a non-aquatic environment. Extracellular electrical activity of photoreceptor organs was recorded at larval and adult stages. We found an increase in photosensitivity as the larva metamorphosed to the adult stage. This is the first report of changes in photosensitivity during the development of any insect described in an ecological context.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2006-06-15

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

  5. Effect of plant and fungous metabolites on Meloidogyne exigua Efeito de metabólitos vegetais e fúngicos sobre Meloidogyne exigua

    Directory of Open Access Journals (Sweden)

    Daniel Rufino Amaral

    2009-01-01

    Full Text Available As nematodes cause great damage to Brazilian coffee production, effective methods to control these parasites are necessary. In a previous work Allium cepa L., Cajanus cajan (L. Mill., Crotalaria juncea L., Ficus elastica Roxb., Ruta graveolens L., Stylosanthes guianensis Aubl., Leucaena leucocephala (Lam. Dewit., Brachiaria decumbens Stapf., Catharanthus roseus G. Don, Tagetes minuta L., Ricinus communis L. and Coffea arabica L. produced active substances against Meloidogyne exigua Goeldi, a nematode widely disseminated through Brazilian coffee fields. Thus, aqueous extracts of such plants, collected in a different season from that of the previous work, as well as crude metabolites produced in liquid medium by Fusarium moniliforme Shelden and Cylindrocarpon magnusianum (Sacc. Woll., were submitted to in vitro assays with M. exigua second-stage juveniles (J2. All plants and fungi produced active substances against J2. Therefore, their metabolites were applied to six-month-old coffee plants inoculated with M. exigua. After 90 days in a greenhouse, those samples obtained from A. cepa, L. leucocephala, R. graveolens and F. moniliforme inhibited the production of galls and eggs by M. exigua, demonstrating potential to control such parasite.Os nematóides acarretam grandes perdas aos produtores brasileiros de café, sendo necessário o desenvolvimento de métodos eficientes para o seu controle. Em trabalho anterior, Allium cepa L., Cajanus cajan (L. Mill., Crotalaria juncea L., Ficus elastica Roxb., Ruta graveolens L., Stylosanthes guianensis Aubl., Leucaena leucocephala (Lam. Dewit., Brachiaria decumbens Stapf., Catharanthus roseus G. Don, Tagetes minuta L., Ricinus communis L. e Coffea arabica L. produziram substâncias ativas contra o nematóide Meloidogyne exigua Goeldi, que é amplamente disseminado pelos cafezais brasileiros. Dando continuidade a esse trabalho, extratos aquosos das plantas mencionadas, coletadas em época diferente daquela

  6. Biting rates and developmental substrates for biting midges (Diptera: Ceratopogonidae) in Iquitos, Peru.

    Science.gov (United States)

    Mercer, David R; Spinelli, Gustavo R; Watts, Douglas M; Tesh, Robert B

    2003-11-01

    Biting midges (Diptera: Ceratopogonidae) were collected at 16 periurban and rural sites around Iquitos, Peru, between 17 October 1996 and 26 May 1997. Culicoides paraensis (Goeldi), the principal vector of Oropouche virus, was the most commonly collected species (9,086 flies) with Culicoides insinuatus Wirth & Blanton second (7,229 flies). Although both species were collected at all sampling sites (linear (distance surveyed approximately 25 km), C. paraensis dominated at northern collection sites (> 90%), whereas C. insinuatus prevailed at southern collection sites (> 60%). C. paraensis were collected from human sentinels at a constant rate throughout daylight hours, at similar rates during wet and dry months, and regardless of rainfall. Larval developmental substrates for C. paraensis included decaying platano (Musa x paradisiaca L. [Musaceae]) stems, stumps, flowers, fruits, and debris beneath platano trees as well as from soil beneath a fruiting mamay (Syzygium malaccense Merr. & Perry [Myrtaceae] ) tree and organic-rich mud along a lake shoreline. C. insinuatus adults likewise emerged from decaying platano and organic-rich mud along a lake shoreline, but also from debris accumulated in the axils of aguaje (Mauritia flexuosa L. [Palmae]) fronds and decaying citrus fruit. Despite high numbers of biting adults near putative substrates, adults of neither species emerged from other decomposing plant material, soil, phytotelmata, or artificial containers. Because both species of biting midges emerged in high numbers from all parts of platano (ubiquitous in Iquitos), it will be challenging to control them through sanitation. PMID:14765657

  7. Dermatozoonosis by Culicoides bite (Diptera, Ceratopogonidae in Salvador, State of Bahia, Brazil

    Directory of Open Access Journals (Sweden)

    Italo A. Sherlock

    1964-01-01

    Full Text Available Os autores iniciam com êste, uma série de trabalhos sôbre a Dermatozoonose provocada pela picada de Culicoides, em Salvador, Bahia, Brasil. No presente, tratam das espécies de Culicoides encontradas em Salvador, baseados na coleta de 2.947 exemplares, durante os anos de 1959 a 1963. Encontraram as 4 espécies seguintes; C. (O. paraensis (Goeldi, 1905 C. (O. limonensis Ortiz & Leon, 1955 C. (C. insignis Lutz, 1913 C. (C. flavivenula Costa Lima, 1937. Não reencontraram o C. (C. maruim, Lutz, 1913 assinalado por fox (1948 e WIRTH & BLANTON (1956 para Salvador. Dessas espécies o C. (C. paraensis se mostrou a predominante, abrangendo 98% de exemplares coletados. Apresentam a distribuição das espécies por bairros e respectivas quantidades coletadas. Finalizando, dão as principais características morfológicas das espécies, ilustrando essas com desenhos do material por êles estudado.

  8. Seasonal distribution of a relatively rare and a relatively common species of Thecomyia at Belém, Pará, Brazil (Diptera: Sciomyzidae

    Directory of Open Access Journals (Sweden)

    Lloyd Knutson

    1989-01-01

    Full Text Available O gênero neotropical Thecomyia (Sciomyzidae consiste de quatro espécies descritas e onze ainda não descritas (Steyskal & Knutson em preparação, sendo a maioria não muito comum. As espécies são muito próximas e grande número delas somente pode ser separado com base na genitália do macho. Somente é conhecida a biologia e uma espécie, T. limbata (Wiedermann, que, preferentemente, preda moluscos aquáticos (Abercrombie & Berg, 1975. A análise de registros de coletas de espécies relativamente raras e relativamente comuns de Thecomyia (172 especimens do Museu Goeldi coletados em Mocambo, Belém, Pará, Brasil proporcionam informações sobre a distribuição sazonal de espécies tropicais e sua relativa abundância. Deste material 160 especimens pertencem à T. longicornis Perty e 12 à Thecomyia sp. n. A primeira foi registrada durante todos os meses do ano, mas a espécie nova somente durante junho e dezembro, sugerindo esta última uma população de adultos anual bimodal.

  9. Usos e apropriações de multimídias na educação para a biodiversidade em escolas de Belém/PA

    Directory of Open Access Journals (Sweden)

    Lúcia das Graças Santana da Silva

    2016-07-01

    Full Text Available This research, carried out under the Capacity Institutional program through the Paraense Emilio Goeldi Museum/MCTI, identified perceptions about the concept of biodiversity in two school communities of elementary and high school in the city of Belém do Pará - Brazil, linked to municipal systems and state education, namely: Reference Center for Environmental Education Foundation Teacher Eidorfe Moreira and State Elementary School and Middle Vilhena Alves. Also identified as the Information and Communication Technologies and multimedia, act as mediators of the processes of teaching and learning about biodiversity in these communities. The methodology used is action research with participant observation (PERUZZO, 2003 and in-depth interviews of semi-open type with semi-structured questions (Duarte, 2009. It was concluded that the concept of biodiversity should be better worked in the school environment, in a structured way and with the pedagogical assistance of ICTs, whose educational use should be favored with the best investments in public education, especially in training and teachers' awareness of the pedagogical use ICT and multimedia.

  10. The Ct-RAE1 protein interacts with Balbiani ring RNP particles at the nuclear pore.

    OpenAIRE

    Sabri, N; Visa, N

    2000-01-01

    RAE1 is an evolutionarily conserved protein that associates with both mRNPs and nucleoporins, and may bridge the interaction between mRNP export cargoes and the nuclear pore complex (NPC). However, the mechanism by which RAE1 functions in mRNA export is still unknown and the time point at which RAE1 interacts with the exported RNP has not been directly investigated. Here we have addressed this question in the Balbiani ring (BR) system of Chironomus tentans using immunoelectron microscopy. The...

  11. Taxonomic notes on Chironomidae (Diptera from Okinawa Island, Japan, with the description of three new species

    Directory of Open Access Journals (Sweden)

    Masaru Yamamoto

    2015-07-01

    Full Text Available Three new species: Ionthosmittia cuneipenne sp. nov., Orthocladius (Euorthocladius okinawanus sp. nov. and Parakiefferiella semiovata sp. nov., are described from Okinawa Island, Ryukyus, Japan. In addition to these species, twelve species are newly recorded from this island. Diagnostic characters of Tokyobrillia tamamegaseta (Kobayashi et Sasa are emended. Pentapedilum yakuabeum Sasa et Suzuki syn. nov. and Polypedilum yakucedeum Sasa et Suizuki syn. nov. are junior synonyms of Ainuyusurika tuberculatum (Tokunaga. Einfeldia kanazawai (Yamamoto is transferred to the genus Chironomus Meigen and its systematic position is discussed.

  12. Bioaccumulation of metals in aquatic insects of streams located in areas with sugar cane cultivation

    Directory of Open Access Journals (Sweden)

    Juliano José Corbi

    2010-01-01

    Full Text Available Streams located in areas of sugar cane cultivation receive elevated concentrations of metal ions from soils of adjacent areas. The accumulation of metals in the sediments results in environmental problems and leads to bioaccumulation of metal ions by the aquatic organisms. In the present study, bioaccumulation of the metals ions Al, Cd, Cr, Cu, Fe, Mg, Mn and Zn in aquatic insects in streams impacted by the sugar cane was evaluated. The results pointed out that the insects were contaminated by the sediment and that the collector organisms as Chironomus species accumulated higher concentration of metals than the predator organisms.

  13. Microscale ecotoxicity testing of Moselle river watershed (Lorraine Province, France) sediments

    OpenAIRE

    Jean François Férard; Karen F. Burga Pérez; Christian Blaise; Alexandre Péry; Pakawadee Sutthivaiyakit; François Gagné

    2015-01-01

    The ecotoxic potential of seven Moselle river watershed sediments was assessed with a battery of bioassays comprised of rapid phototrophic [LuminoTox solid phase (L-SPA) and elutriate (L-ELU) assays] and bacterial [Microtox solid phase assay (M-SPA)] exposure tests, as well as with two micro-invertebrate solid phase tests conducted with Hydra attenuata (lethal and sublethal effects solid phase assay, HL-SPA and HSL-SPA) and Chironomus riparius. Measured effects of sediments and their elutriat...

  14. Identification of transport processes in bioirrigated muddy sediments by [18F]fluoride PET (Positron Emission Tomography).

    Science.gov (United States)

    Roskosch, Andrea; Lewandowski, Jörg; Bergmann, Ralf; Wilke, Florian; Brenner, Winfried; Buchert, Ralph

    2010-06-01

    In aquatic environments transport processes across the sediment-water interface are intensified by bioirrigating macrozoobenthos. Transport processes caused by Chironomus plumosus larvae dwelling in U-tubes were investigated by dynamic small animal Positron Emission Tomography (PET) with [18F]fluoride. Significant tracer transport from the burrows into the sediment was detected; penetration was deeper at the outlet branch of the burrow than at the inlet branch. Hence, advection plays a significant role in exchange between water in the burrows and muddy sediment. PMID:20185319

  15. Identification of transport processes in bioirrigated muddy sediments by [18F]fluoride PET (Positron Emission Tomography)

    International Nuclear Information System (INIS)

    In aquatic environments transport processes across the sediment-water interface are intensified by bioirrigating macrozoobenthos. Transport processes caused by Chironomus plumosus larvae dwelling in U-tubes were investigated by dynamic small animal Positron Emission Tomography (PET) with [18F]fluoride. Significant tracer transport from the burrows into the sediment was detected; penetration was deeper at the outlet branch of the burrow than at the inlet branch. Hence, advection plays a significant role in exchange between water in the burrows and muddy sediment.

  16. Identification of transport processes in bioirrigated muddy sediments by [18F]fluoride PET (Positron Emission Tomography)

    Energy Technology Data Exchange (ETDEWEB)

    Roskosch, Andrea [Department of Ecohydrology, Leibniz-Institute of Freshwater Ecology and Inland Fisheries, Mueggelseedamm 310, 12587 Berlin (Germany)], E-mail: roskosch@igb-berlin.de; Lewandowski, Joerg [Department of Ecohydrology, Leibniz-Institute of Freshwater Ecology and Inland Fisheries, Mueggelseedamm 310, 12587 Berlin (Germany); Bergmann, Ralf [Radiopharmaceutical Biology Division, Forschungszentrum Dresden-Rossendorf, Bautzener Landstrasse 400, 01328 Dresden (Germany); Wilke, Florian [Department of Nuclear Medicine, University Medical Center Hamburg-Eppendorf, Martinistr. 52, 20246 Hamburg (Germany); Brenner, Winfried; Buchert, Ralph [Department of Nuclear Medicine, University Medical Center Hamburg-Eppendorf, Martinistr. 52, 20246 Hamburg (Germany); Present address: Department of Nuclear Medicine, Charite, Universitaetsmedizin Berlin, Chariteplatz 1, 10117 Berlin (Germany)

    2010-06-15

    In aquatic environments transport processes across the sediment-water interface are intensified by bioirrigating macrozoobenthos. Transport processes caused by Chironomus plumosus larvae dwelling in U-tubes were investigated by dynamic small animal Positron Emission Tomography (PET) with [18F]fluoride. Significant tracer transport from the burrows into the sediment was detected; penetration was deeper at the outlet branch of the burrow than at the inlet branch. Hence, advection plays a significant role in exchange between water in the burrows and muddy sediment.

  17. Demonstration of a dynamic, transcription-dependent organization of pre- mRNA splicing factors in polytene nuclei

    OpenAIRE

    1996-01-01

    We describe the dynamic organization of pre-mRNA splicing factors in the intact polytene nuclei of the dipteran Chironomus tentans. The snRNPs and an SR non-snRNP splicing factor are present in excess, mainly distributed throughout the interchromatin. Approximately 10% of the U2 snRNP and an SR non-snRNP splicing factor are associated with the chromosomes, highly enriched in active gene loci where they are bound to RNA. We demonstrate that the splicing factors are specifically recruited to a ...

  18. Developing acute-to-chronic toxicity ratios for lead, cadmium, and zinc using rainbow trout, a mayfly, and a midge

    Science.gov (United States)

    Mebane, C.A.; Hennessy, D.P.; Dillon, F.S.

    2008-01-01

    In order to estimate acute-to-chronic toxicity ratios (ACRs) relevant to a coldwater stream community, we exposed rainbow trout (Oncorhynchus mykiss) to cadmium (Cd), lead (Pb), and zinc (Zn) in 96-h acute and 60+ day early-life stage (ELS) exposures. We also tested the acute and sublethal responses of a mayfly (Baetis tricaudatus) and a midge (Chironomus dilutus, formerly C. tentans) with Pb. We examine the statistical interpretation of test endpoints and the acute-to-chronic ratio concept. Increasing the number of control replicates by 2 to 3x decreased the minimum detectable differences by almost half. Pb ACR estimates mostly increased with increasing acute resistance of the organisms (rainbow trout ACRs ACR estimates by up to a factor of four. When calculated using the geometric means of the no- and lowest-observed effect concentrations, ACRs with rainbow trout and Cd were 0.6 and 0.95; Zn about 1.0; and for Pb 3.3 and 11. The comparable Pb ACRs for the mayfly and Chironomus were 5.2 and 51 respectively. Our rainbow trout ACRs with Pb were about 5-20x lower than earlier reports with salmonids. We suggest discounting previous ACR results that used larger and older fish in their acute tests. ?? 2007 GovernmentEmployee: U.S. Geological Survey.

  19. Productivity of chironomid larvae exposed to oil sands process water : in situ vs. lab bioassay results

    Energy Technology Data Exchange (ETDEWEB)

    Kennedy, K.; Ciborowski, J. [Windsor Univ., ON (Canada)

    2010-07-01

    Oil sands process water (OSPW) contains toxic concentrations of salts and napthenic acids that may compromise wetland reclamation efforts. The productivity of wetland biota is one of the criteria used by the Alberta government to determine if land leased to oil sands mining companies is restored. This study determined how chironomid productivity is influenced by the water from oil sands process material (OSPM) affected wetland. In this study, 26 10-day in situ and laboratory bioassays from water of three oil sands process material (OSPM) were compared with water from 3 reference wetlands to determine the influence of water from OSPM affected wetlands on chironomid productivity. Parallel studies were conducted with Chironomus riparius lab-cultured larvae and Chironomus sp larvae cultured from egg masses collected from an OSPW-affected wetland. In situ, chironomids were housed in small cylinders with fine-mesh netting to allow water exchange and contact with the sediment. Preliminary estimates of chironomids emerging from study wetlands indicated that native and lab cultured chironomids are not uniformly responsive to OSPW.

  20. Bamboo stumps as mosquito larval habitats in Darjeeling Himalayas,India:A spatial scale analysis

    Institute of Scientific and Technical Information of China (English)

    Gautam Aditya; Rakesh Tamang; Dipendra Sharma; Francis Subba; Goutam K.Saha

    2008-01-01

    Bamboo stumps can be a congenial breeding habitat of the mosquitoes.In view of this,a preliminary assessment of the dipteran immatures inhabiting the stumps of bamboo groves in the Darjeeling Himalayas was carried out at a spatial scale.Of the 104 stumps of Dendrocalamus hamiltoni surveyed,70 were found to host immatures of three dipteran species,the mosquitoes Aedes aegypti and Culex quinquefasciatus and the midges Chironomus sp.in varying densities.Though the stumps varied in diameter,in each stump on average 12.1 immatures were found.The abundance of the immatures was positively correlated with the diameter of the stumps (r = +0.382;P < 0.001) but negatively with the pH of the water present in the stumps (r = -0.336;P < 0.01).The coefficient of association was found to be +8.4 for the Ae.aegypti and Chironomus immatures,while in the rest of the species pair the association seemed to be independent.Thus it can be concluded that the stumps in the bamboo groves of Darjeeling Himalayas provides a favourable habitat for the mosquito and chironomid immatures.

  1. Impact of heavy metals on macro-invertebrate fauna of the thaddo stream

    International Nuclear Information System (INIS)

    Impact of some heavy metals like zinc, lead, copper, chromium and cadmium were studied at four spots on the macro-invertebrate fauna of the Thaddo stream, a tributary of Malir River. This was in correlation with an earlier study on the physico-chemical aspects of water which showed a severe pollution in this stream. Present data for the qualitative and quantitative analyses of macro-invertebrates and the ranges of heavy metals (Zn 0.5-3.5, Pb 0.90-1.42, Cu 0.35-0.93, Cr 0.0-0.08 and Cd 0.003-0.01 ppm) in the water samples also indicate high level of pollution in the stream. Macro-invertebrate fauna comprises only of aquatic insects which include larvae of Chironomus spp., adults of the Notonectus sp., and nymphs of Gomphus sp. (dragon fly) belonging to the order Diptera , Hemiptera and Odonata, respectively. Quantitatively Notonectus sp. predominated and followed by Chironomus larvae. The maximum concentrations of all heavy metals were recorded at spot 3. A general trend of increase was observed from up stream to down stream regions particularly in the level of zinc. However, a reverse trend was observed in the abundance of macro-invertebrates with a great reduction at spot 4. The statistical analysis of the data generally indicates a negative correlation between the values of the studied heavy metals and the abundance of macro-invertebrates throughout this study. (author)

  2. Conversion of carotenoids into vitamins A(1) and A(2) in two species of freshwater fish.

    Science.gov (United States)

    Gross, J; Budowski, P

    1966-12-01

    1. Examination of two zooplankton species predominating in fish ponds, Daphnia magna and Chironomus larvae, revealed the presence of alpha- and beta-carotene, echinenone, canthaxanthin and 3-hydroxy-4-oxo-beta-carotene in Daphnia, and beta-carotene and cryptoxanthin ester in Chironomus. No specific provitamins A(2) (containing a 3,4-dehydro-beta-ionone ring) were detected. 2. Guppies (Lebistes reticulatus) and platies (Xiphophorus variatus) were found to form vitamin A from beta-carotene and from its oxygen-containing derivatives isozeaxanthin, canthaxanthin and astaxanthin. Slight conversion into vitamin A(2) seemed to occur simultaneously. 3,4-Dehydro-3'-hydroxy-beta-carotene formed little vitamin A, and the latter was mainly of the A(2) type. Lutein was devoid of provitamin A properties. 3. In addition to vitamin A, beta-carotene was detected in fish receiving the 4-oxo- and 4-hydroxy-carotenoids. A reaction scheme for the conversion of carotenoids into retinal and and 3,4-dehydroretinal is presented. 4. It is concluded that natural 4-oxo derivatives of beta-carotene may play a significant role as vitamin A precursors for fish. PMID:16742455

  3. Conversion of carotenoids into vitamins A1 and A2 in two species of freshwater fish

    Science.gov (United States)

    Gross, Jeana; Budowski, P.

    1966-01-01

    1. Examination of two zooplankton species predominating in fish ponds, Daphnia magna and Chironomus larvae, revealed the presence of α- and β-carotene, echinenone, canthaxanthin and 3-hydroxy-4-oxo-β-carotene in Daphnia, and β-carotene and cryptoxanthin ester in Chironomus. No specific provitamins A2 (containing a 3,4-dehydro-β-ionone ring) were detected. 2. Guppies (Lebistes reticulatus) and platies (Xiphophorus variatus) were found to form vitamin A from β-carotene and from its oxygen-containing derivatives isozeaxanthin, canthaxanthin and astaxanthin. Slight conversion into vitamin A2 seemed to occur simultaneously. 3,4-Dehydro-3′-hydroxy-β-carotene formed little vitamin A, and the latter was mainly of the A2 type. Lutein was devoid of provitamin A properties. 3. In addition to vitamin A, β-carotene was detected in fish receiving the 4-oxo- and 4-hydroxy-carotenoids. A reaction scheme for the conversion of carotenoids into retinal and and 3,4-dehydroretinal is presented. 4. It is concluded that natural 4-oxo derivatives of β-carotene may play a significant role as vitamin A precursors for fish. PMID:16742455

  4. Taxonomic and numeric structure of Chironomidae (Diptera in different habitats of a Neotropical floodplain

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    Cristina Márcia de Menezes Butakka

    2014-09-01

    Full Text Available We characterized the local benthic Chironomidae by analyzing the numerical density, biomass, diversity index of Shannon-Wiener and dominance of larvae in the main channel of the Ivinhema River, in a secondary channel, in five lakes connected to the main channel and in five lakes without connection. Of the 68 taxa identified, Aedokritus sp., Tanytarsus sp., Chironomus strenzkei Fittkau, 1968 and Procladius sp.1 were found in all sampling sites and were considered morphospecies with greater of greatest ecological plasticity. Chironomus strenzkei Fittkau, 1968, contributed with the greatest biomass in the central region of lakes without connection, whereas Aedokritus sp. dominated in the littoral of lakes. The greater values of diversity indices in the littoral region of channels were due to the greater water flow and to the higher food availability in these areas. The dominance indices, by contrast, were greater on the central region of these environments. The littoral region has exclusive characteristics, representing habitats that could play important controlling in the numerical density and index diversity on the ecosystem, whereas that the biomass of benthic invertebrates in the central region in some biotopes would have different spatial probably according organisms drift.

  5. Contribuição para o conhecimento da taxonomia, ecologia e fitogeografia de Briófitas da Amazônia Oriental Contribution to the taxonomy, ecology and phytogeographical knowledge of Bryophytes from Eastern Amazonia

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    Lisi Dámaris Pereira Alvarenga

    2009-09-01

    Full Text Available O presente trabalho documenta o inventário da brioflora da Estação Científica Ferreira Penna (ECFPn, localizada na FLONA Caxiuanã (1º42'30"S - 51º31'45"W, Melgaço - Pará, realizado por ocasião da primeira chamada do Programa de Residência em Estudos Amazônicos, iniciativa do Museu Paraense Emílio Goeldi. Musgos e Hepáticas foram amostrados nos ecossistemas de mata de terra firme, várzea, igapó, capoeiras e campina, e analisadas quanto à composição, riqueza e diversidade. Foram registradas 1081 ocorrências de briófitas de 120 espécies, sendo 79 hepáticas e 41 musgos, das quais oito hepáticas são novas referências para o Estado do Pará. As famílias de maior riqueza e assiduidade foram Lejeuneaceae (58 spp., Calymperaceae (13 spp., Sematophyllaceae (9 spp. e Plagiochilaceae (7 spp.. As comunidades que melhor se fizeram representar foram a epífita (97 espécies/ 565 ocorrências e a epíxila (65 spp./ 242 ocorr., seguidas pelas comunidades epífila (27 spp./ 174 ocorr. e terrícola (15 spp./ 96 ocorr. e o ecossistema que apresentou maior riqueza e diversidade foi mata de terra firme. Quanto à composição nos substratos inventariados, foi observada uma inversão gradativa na proporção de riqueza entre hepáticas/musgos, sendo as primeiras fortemente dominantes em folha, moderadamente dominantes em tronco vivo e morto, ao passo que musgos predominaram nos demais. Os resultados obtidos neste inventário, inclusive as novas referências para o Estado, contribuem para o entendimento dos padrões de riqueza e diversidade na Floresta Amazônica e enriquecem a flora conhecida para o Estado do Pará.This paper presents the floristic survey of Bryophytes from Ferreira Penna Scientific Station (ECFPn, located in the FLONA Caxiuanã (1º42'30"S - 51º31'45"W, Melgaço - Pará, that was undertaken in the first stage of the Residence Program in Amazonian Studies, a project of the Museu Paraense Emílio Goeldi. Mosses and

  6. Social wasps of two wetland ecosystems in brazilian Amazonia (Hymenoptera, Vespidae, Polistinae Vespas sociais de duas áreas úmidas na Amazônia brasileira (Hymenoptera, Vespidae, Polistinae

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    Orlando Tobias Silveira

    2008-01-01

    Full Text Available In Brazilian Amazonia, 20 genera and more than 200 species of polistine wasps are recorded. Local faunas with 70 to 80 species are usually found in non floodable forest environments. However, a variety of wetlands exist in the region, the most expressive in surface area being varzea systems. In this paper, information is presented on polistines from two areas of wetlands in the Brazilian states of Amazonas and Amapá. These are reciprocally compared and also with nearby terra firme locations. Collecting methods consisted of active search for nests, handnetting and automatic trapping of individuals. Forty-six species of 15 genera were collected in Mamirauá, AM, most being widespread common wasps. However, five species deserve special mention in virtue of rarity and/or restricted distribution: Metapolybia rufata, Chartergellus nigerrimus, Chartergellus punctatior, Clypearia duckei, and Clypearia weyrauchi. In Região dos Lagos, AP, 31 species of 9 genera were collected, nearly all being common species with the exception of some Polistes, like P. goeldi and P. occipitalis. Even though less rich than vespid faunas from terra firme habitats, the Mamirauá fauna proved to be quite expressive considering limitations imposed by the hydrological regime. In Região dos Lagos, however, the very low diversity found was below the worst expectations. The virtual absence of otherwise common species in environments like tidal varzea forests along Araguari River is truly remarkable. The causes of low diversity are probably related to isolation and relative immaturity of the region, allied to strong degradation of forested habitats.Vinte gêneros e mais de 200 espécies de vespas sociais são registrados na Amazônia brasileira. Faunas locais com 70 a 80 espécies são usualmente encontradas em florestas não inundáveis. Entretanto, uma grande variedade de áreas úmidas existe na região, com destaque para os sistemas de várzea. Neste artigo, apresentamos

  7. Biologia floral de Virola surinamensis (Rol. Warb. (Myristicaceae Virola surinamensis (Rol. Warb. (Myristicaceae floral biology

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    Mario Augusto Gonçalves Jardim

    2007-12-01

    Full Text Available Neste artigo são apresentadas informações sobre a biologia floral de Virola surinamensis (Rol. Warb. (Myristicaceae, espécie florestal dióica de relevante importância econômica na região amazônica. O estudo foi realizado em uma área de várzea próximo à bacia do igarapé Murutucum, lado direito do rio Guamá, localizada no Campus da Faculdade de Ciências Agrárias do Pará, na cidade de Belém, Estado do Pará, no período de janeiro a dezembro de 2001. Avaliou-se a biologia floral desde o aparecimento dos botões florais até a senescência das flores estaminadas, bem como a formação de frutos nas flores pistiladas. Testes bioquímicos foram aplicados para verificação de odor, pigmentos, osmóforos e receptividade do estigma. A observação no comportamento dos visitantes florais foi realizada durante o período diurno, registrando-se os horários de visitas, tempo de permanência na flor e freqüência; alguns indivíduos foram coletados com rede entomológica e identificados no Departamento de Zoologia do Museu Paraense Emílio Goeldi. A antese ocorreu entre 6 e 16 h nas flores estaminadas e entre 8 e 16 h nas flores pistiladas; a presença de odor foi constatada apenas nas flores estaminadas, enquanto os pigmentos e osmóforos foram encontrados em ambas as flores; o estigma mostrou-se receptivo no período entre 12 e 14 h. Os insetos da ordem diptera foram os visitantes mais freqüentes nas flores estaminadas e pistiladas e as espécies Copestylum sp. e Erystalys sp., as responsáveis pela polinização.Information was obtained on the floral biology of Virola surinamensis (Rol. Warb. (Myristicaceae, a dioecious arboreal species of great importance for the Amazon region economy. The study was carried out in the floodplain area near the Murucutu stream, on the right side of the Guamá River, at the Universidade Federal Rural da Amazônia-UFRA, Belém-Pará , from January to December 2001. Floral biology was assessed from

  8. New species of titi monkey, genus Callicebus Thomas, 1903 (Primates, Pitheciidae, from Southern Amazonia, Brazil

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    Julio César Dalponte

    2014-01-01

    Full Text Available The genus Callicebus is one of the most diverse Neotropical primate groups, with 31 recognized species. However, large knowledge gaps still exist regarding the diversity of this genus. Such gaps are gradually being filled due to recent intensification of sampling efforts. Several geographic distributions have been better delimited, and six new species have been described in the last 15 years. The goal of the present study is to describe a new species of Callicebus belonging to the Callicebus moloch species group, recently discovered in an area previously considered to be part of the geographic distribution of C. cinerascens. Data collection was conducted through direct observations, specimen collection and interviews with local residents during four expeditions. Specimens were deposited in the mammalian collection of the Museu Paraense Emílio Goeldi.. For a comparative evaluation, we examined specimens of the other species of the Callicebus moloch species group, especially the geographically neighboring forms, C. bernhardi and C. cinerascens. We examined 10 chromatic characters of the fur. In addition to body mass, we verified the conventional external variables and 26 craniometric variables. The new species differs from all other Amazonian Callicebus by an exclusive combination of characters, being easily distinguished by the light gray line of the forehead, dark ocher sideburns and throat, dark gray portions of the torso and flanks, and uniformly orange tail. The geographic distribution of the new species is limited by the Roosevelt and Aripuanã rivers, in the states of Mato Grosso and Amazonas, Brazil. Approximately 25% (1,246.382 ha of this area falls within conservation areas, with five areas of sustainable use (746,818 ha and three of integral protection (499,564 ha. Furthermore, a considerable portion of the distribution area is located within indigenous lands (1,555.116 ha - 32%. Therefore, 57% (2,801.498 ha of the occurrence area of

  9. The first species of the genus Caponina from Brazilian Amazonia (Araneae: Caponiidae).

    Science.gov (United States)

    Brescovit, Antonio D; Ruiz, Alexander Sánchez

    2013-01-01

    The genus Caponina Simon, 1891 comprises eleven species of medium-sized, soil-dwelling caponiids. Most members of Caponina have six eyes, but some have five, four, three or two eyes (Brignoli 1977, Platnick 1994). The genus is widespread in South and Central America (Platnick 2012). To date, only three species have been recorded from Brazil: Caponina alegre Platnick, 1994 from the state of Rio Grande do Sul, C. notabilis (Mello-Leitão, 1939) from the states of Paraná and Rio Grande do Sul, and C. tijuca Platnick, 1994 from the state of Rio de Janeiro (Platnick 1994). In this paper we describe a new species from the state of Pará, in Brazilian Amazonia. Caponina papamanga new species was collected during the "Butantan na Amazonia" project, founded by the Instituto Butantan. The phylogenetic relationships of C. papamanga could not be studied, but the greatly elongated embolus, the dorsal tubercle on the palpal femur (Figs. 7, 9) and the massive epigynal sclerotizations (Fig. 10) suggest that this species belongs to the monophyletic Andean group proposed by Platnick (1994: 7). All morphological observations and illustrations were made using a Leica MZ12 stereomicroscope with camera lucida. The epigynum was dissected and immersed in clove oil for visualization of internal structures following Levi (1965). Descriptions and measurements follow Platnick (1994). Measurements are given in millimeters. Scanning electron microscope (SEM) images were taken using a Jeol-JSM-5200 with attached SLR digital camera. The material examined was deposited in the collections of the Instituto Butantan, Sgo Paulo (IBSP, curator: D.M. Barros Battesti) and the Museu Paraense Emílio Goeldi, Belém (MPEG, curator: A.B. Bonaldo).

  10. Topografia do cone medular da preguiça

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    Ana R. Lima

    2011-07-01

    Full Text Available A anestesia caudal foi proposta pela primeira vez em 1926 e diversas técnicas foram desenvolvidas para anestesiar os nervos espinhais lombares e sacrais. Os métodos para anestesia epidural exigem conhecimento da anatomia da região envolvida. Desta forma, objetivou-se determinar a topografia do cone medular da preguiça (Bradipus variegatus, para fornecer recursos aos profissionais da área clínica para que, desta forma, seja possível a realização de anestesia epidural nesta espécie silvestre de nossa fauna. Foram dissecados quatro exemplares adultos de preguiça, dois machos e duas fêmeas que foram a óbito por causas naturais e obtidos junto ao Parque Zoobotânico do Museu Paraense Emilio Goeldi, Belém/Pará. Após a dissecação observou-se que o cone medular encontra-se entre as vértebras L3 e S1 com comprimento médio de 2,7cm, e a intumescência lombar apresentou comprimento médio de 1,0cm, estando localizada entre L1 e L3 nos quatro animais estudados. Desta forma, conclui-se que o melhor local para a realização de anestesia epidural na preguiça está entre as vértebras L1 e L3

  11. Hand specialization, sympatry, and mixed-species associations in callitrichines.

    Science.gov (United States)

    César, J; Bicca-Marques, J C

    1999-04-01

    Hand morphology in callitrichines (i.e., tamarins, marmosets, and Goeldi's monkey) is correlated with positional and foraging behaviors. This study examines hand shape in callitrichines using an allometric approach. It addresses a series of questions relating hand anatomy, insect foraging behavior, and resource partitioning in callitrichines. The main questions are: 1. Do the hands of Leontopithecus differ in shape from all other callitrichine taxa allowing it to perform highly manipulative prey foraging behaviors? 2. Are the hands of Saguinus fuscicollis adapted to manipulative foraging, and are they functionally similar to Leontopithecus' hands? 3. Is hand morphology in S. fuscicollis more similar to the hand morphology of sympatric tamarin species with whom it does not form mixed species troops (S. nigricollis and S. tripartitus) than to those sympatric tamarin species with whom it does form mixed troops (S. mystax, S. labiatus, and S. imperator)? Measurements of hand length (HL), width (HW), and thickness (HT) were taken from 1350 museum specimens of callitrichines (Callithrix, Cebuella, Leontopithecus, Saguinus, and Callimico), squirrel monkeys (Saimiri), and owl monkeys (Aotus). The analysis indicates that hand shape covaries with foraging strategy. Specifically, the hands of Leontopithecus are adapted for manipulative foraging and are relatively longer and more slender than the hands of other callitrichines. A similar pattern is observed in the hands of S. fuscicollis, S. tripartitus and S. nigricollis. These latter species, however, differ significantly in shape from all other tamarin species. Large differences in hand morphology are observed among tamarin species that form mixed-species troops. These anatomical differences may permit resource partitioning and coexistence among these closely related taxa. Hand shape, expressed as log HLGM (logged hand length divided by the geometric mean of all measurements), is a good predictor of manipulative and non

  12. Usos e apropriações de multimídias na educação para a biodiversidade em escolas de Belém/PA

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    Mayara Santos Maciel

    2016-01-01

    Full Text Available Esta pesquisa, realizada no âmbito do Programa de Capacitação Institucional através do Museu Paraense Emilio Goeldi/MCTI, identificou as percepções sobre o conceito de biodiversidade em duas comunidades escolares de Ensino Fundamental e Médio da cidade de Belém do Pará - Brasil, vinculadas aos sistemas municipal e estadual de ensino, a saber: Fundação Centro de Referência em Educação Ambiental Professor Eidorfe Moreira e Escola Estadual de Ensino Fundamental e Médio Vilhena Alves. Também identificou como as Tecnologias da Informação e da Comunicação e multimídias atuam como mediadoras dos processos de ensino e aprendizado sobre biodiversidade nestas comunidades. Como metodologia foi utilizada a pesquisa-ação com observação participante (PERUZZO, 2003 e entrevistas em profundidade do tipo semi-abertas com questões semi-estruturadas (Duarte, 2009. Concluiu-se que o conceito de biodiversidade deve ser melhor trabalhado em âmbito escolar, de uma forma estruturada e com o auxílio pedagógico das TICs, cujo uso educativo deve ser favorecido com melhores investimentos na educação pública, principalmente na formação e sensibilização de professores para o uso pedagógico das TICs e multimídias.

  13. Reproduction and diet of Imantodes cenchoa (Dipsadidae: Dipsadinae from the Brazilian Amazon

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    Kellen R. M. de Sousa

    2014-02-01

    Full Text Available Imantodes cenchoa (Linnaeus, 1758 is distributed from the east coast of Mexico to Argentina. In Brazil, it occurs in the north, central-west and northeast regions. We present information on the reproductive biology and diet of I. cenchoa from analysis of 314 specimens deposited in the Herpetological Collection of the Museu Paraense Emílio Goeldi (MPEG. Imantodes cenchoa displays sexual dimorphism in the snout-vent length, where sexually mature females are larger than mature males (t = 4.02, p < 0.01; N males = 150, N females = 71, head length (f1.218 = 98.29, p < 0.01; N males = 150, N females = 71, and head width (f1.218 = 112.77, p < 0.01, N males = 150; N females = 71. Bi-sexual maturity is observed, with males becoming sexually mature earlier than females. Females with eggs were recorded from November to January (rainy season and from April to July (dry season, suggesting two reproductive peaks throughout the year, with recruitment occurring mainly during the rainy season, when there is a greater supply of food. Imantodes cenchoa is a nocturnal active forager, capturing prey that are asleep on the vegetation. In 32.80% of the analyzed specimens, food contents were present, of which 84.11% were lizards of the genera Norops (69.16%, N = 74 and Gonatodes (14.95%, N = 16. The other 15.89% of the contents were made up of items in an advanced state of digestion, preventing their identification. Some specimens had more than one food item in their digestive tract, accounting for 107 prey items in total. There was no ontogenetic variation in the diet of I. cenchoa, and the predominant direction of prey ingestion was antero-posterior (71.96%. Larger snakes tended to feed on larger prey, although these did not exclude small prey from their diet.

  14. Tongue papillae morphology of brown-throated sloth Bradypus variegatus (SCHINZ, 1825

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    D.M. Martins

    2014-10-01

    Full Text Available The Bradypus variegatus inhabits the forests of South America and feeds from leaves, branches and sprouts from different plants. Due to its diet and the lack of literature on the morphological aspect of Xenarthras, five Bradypus variegatus tongues from animals which died from natural causes were evaluated, and they came from Pará State Museum Emílio Goeldi and were donated to the Laboratory of Animal Morphological Research (LaPMA from UFRA, for revealing the different types of papillae and epithelial-connective tissue. Macroscopically, the tongues presented elongated shape, rounded apex, body, root, median sulcus in the root's apex, and two vallate papillae. The mucous membrane of the tongue revealed a keratinized stratified pavement epithelium, while the ventral surface of the tongue was thin and smooth, not provided with any type of papillae. However, the dorsal surface of the tongue was irregular with the presence of three types of papillae: filiform, fungiform and vallate papillae. The filiform papillae found were of a simple type, presenting a rounded base, irregularly distributed with a larger concentration and development on the tongue's apex and body. The fungiform papilla showed a practically smooth surface with irregular format, with the presence of gustatory pores; these were found all over the dorsal surface, with larger concentration at the rostral part of the apex. Only two vallate papillae were observed disposed in the root of the tongue, surrounded by a deep groove, and revealing several taste buds. The tongues from Bradypus variegatus presented gustatory papillae similar to the ones described for other Xenarthras species and wild mammals.

  15. Light sheet microscopy for single molecule tracking in living tissue.

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    Jörg Gerhard Ritter

    Full Text Available Single molecule observation in cells and tissue allows the analysis of physiological processes with molecular detail, but it still represents a major methodological challenge. Here we introduce a microscopic technique that combines light sheet optical sectioning microscopy and ultra sensitive high-speed imaging. By this approach it is possible to observe single fluorescent biomolecules in solution, living cells and even tissue with an unprecedented speed and signal-to-noise ratio deep within the sample. Thereby we could directly observe and track small and large tracer molecules in aqueous solution. Furthermore, we demonstrated the feasibility to visualize the dynamics of single tracer molecules and native messenger ribonucleoprotein particles (mRNPs in salivary gland cell nuclei of Chironomus tentans larvae up to 200 microm within the specimen with an excellent signal quality. Thus single molecule light sheet based fluorescence microscopy allows analyzing molecular diffusion and interactions in complex biological systems.

  16. Selenium assimilation and loss by an insect predator and its relationship to Se subcellular partitioning in two prey types

    International Nuclear Information System (INIS)

    Subcellular selenium (Se) distributions in the oligochaete Tubifex tubifex and in the insect Chironomus riparius did not vary with Se exposure duration, which was consistent with the observations that the duration of prey Se exposure had little influence on either Se assimilation or loss by a predatory insect (the alderfly Sialis velata). However, these two prey types differed in how Se was distributed in their cells. Overall, the predator assimilated a mean of 66% of the Se present in its prey, which was similar to the mean percentage of Se in prey cells (62%) that was theoretically available for uptake (that is, Se in the protein and organelle fractions). Likewise, data for cadmium, nickel and thallium suggest that predictions of trace element transfer between prey and predator are facilitated by considering the subcellular partitioning of these contaminants in prey cells. - Selenium assimilation by a predatory aquatic insect depends on Se availability in the cells of its prey

  17. AcEST: BP917171 [AcEST

    Lifescience Database Archive (English)

    Full Text Available YMU001_000097_B09 441 Adiantum capillus-veneris mRNA. clone: YMU001_000097_B09. BP91717...1 CL1480Contig1 Show BP917171 Clone id YMU001_000097_B09 Library YMU01 Length 441 Definition Adiantum ca...pillus-veneris mRNA. clone: YMU001_000097_B09. Accession BP917171 Tissue type prothallium Developmental stag...leic Acids Res. 25:3389-3402. Query= BP917171|Adiantum capillus-veneris mRNA, clo...G 211 >sp|Q03376|BAR3_CHITE Balbiani ring protein 3 OS=Chironomus tentans GN=BR3 PE=2 SV=1 Length = 17

  18. Intrinsic fluctuations and driven response of insect swarms

    Science.gov (United States)

    Ni, Rui; Puckett, James G.; Dufresne, Eric R.; Ouellette, Nicholas T.

    2015-03-01

    Much of our understanding of collective behaviour in social animals comes from passive observations of animal groups. To understand the group dynamics fully, however, we must also characterize the response of animal aggregations to disturbances. Using three-dimensional particle tracking, we study both the intrinsic fluctuations of laboratory swarms of the non-biting midge Chironomus riparius and the response of the swarms to controlled external perturbations: the amplitude-modulated sound of male midge wingbeats. Although these perturbations have an insignificant effect on the behavior of individuals, we find that they can have a strong impact on the collective movement. Intriguingly, the response of the swarm is similar reminiscent to of that of a passive equilibrium system to an external driving force, with microscopic fluctuations underlying combining to produce a macroscopic linear response over a wide range of driving frequencies.

  19. Stream Macroinvertebrate Occurrence along Gradients in Organic Pollution and Eutrophication

    DEFF Research Database (Denmark)

    Friberg, Nikolai; Skriver, Jens; Larsen, Søren Erik;

    2010-01-01

    We analysed a large number of concurrent samples of macroinvertebrate communities and chemical indicators of eutrophication and organic pollution [total-P, total-N, NH4-N, biological oxygen demand (BOD5)] from 594 Danish stream sites. Samples were taken over an 11-year time span as part...... to be slightly less sensitive than Leuctra. Other plecopterans such as Isoperla showed a similar type of response curve to Leuctra (negative exponential) but occurred at sites with relatively high concentrations of BOD5 up to 3-4 mg L-1. In contrast, the response curve of the isopod Asellus aquaticus followed...... a saturation function reaching a plateau above 3-4 mg L-1 BOD5 and the dipteran Chironomus showed an exponential increase in occurrence with increasing BOD5 concentration. Macroinvertebrate occurrence appeared to be related primarily to concentrations of BOD5, NH4-N and total-P whereas there were almost...

  20. The exosome associates cotranscriptionally with the nascent pre-mRNP through interactions with heterogeneous nuclear ribonucleoproteins

    DEFF Research Database (Denmark)

    Hessle, Viktoria; Björk, Petra; Sokolowski, Marcus;

    2009-01-01

    Eukaryotic cells have evolved quality control mechanisms to degrade aberrant mRNA molecules and prevent the synthesis of defective proteins that could be deleterious for the cell. The exosome, a protein complex with ribonuclease activity, is a key player in quality control. An early quality...... checkpoint takes place cotranscriptionally but little is known about the molecular mechanisms by which the exosome is recruited to the transcribed genes. Here we study the core exosome subunit Rrp4 in two insect model systems, Chironomus and Drosophila. We show that a significant fraction of Rrp4...... is associated with the nascent pre-mRNPs and that a specific mRNA-binding protein, Hrp59/hnRNP M, interacts in vivo with multiple exosome subunits. Depletion of Hrp59 by RNA interference reduces the levels of Rrp4 at transcription sites, which suggests that Hrp59 is needed for the exosome to stably interact...

  1. THE CHIRONOMIDAE ASSEMBLAGES IN SOMESUL MIC RIVER (ROMANIA DURING 1996 AND 1997

    Directory of Open Access Journals (Sweden)

    Maria-Monica Tudorancea

    2001-01-01

    Full Text Available The communities of Chironomidae larvae in the Gilau – Gherla sector of the Somesul Mic River (Transylvania, Romania were studied during 1996 and 1997 in order to compare their species composition and to see if their component species could be good indicators for water quality deterioration. A total of 102 species were recorded, out of which 12 are new records for the Romanian fauna. Four of these species are known only from East Asia and from the North America. Some species such as Chironomus thumi, Microcricotopus bicolor, Dicrotendipes nervosus and Dicrotendipes notatus occurred in organically enriched waters. Other species, such as Cricotopus algarum, Cricotopus bicinctus, Cricotopus tremulus and Cricotopus trifasciatus occurred in both clean and organically polluted water which indicate they are not good bioindicators for water quality deterioration.

  2. Velocity correlations in laboratory insect swarms

    Science.gov (United States)

    Ni, R.; Ouellette, N. T.

    2015-12-01

    In contrast to animal groups such as bird flocks or migratory herds that display net, directed motion, insect swarms do not possess global order. Without such order, it is difficult to define and characterize the transition to collective behavior in swarms; nevertheless, visual observation of swarms strongly suggests that swarming insects do behave collectively. It has recently been suggested that correlation rather than order is the hallmark of emergent collective behavior. Here, we report measurements of spatial velocity correlation functions in laboratory mating swarms of the non-biting midge Chironomus riparius. Although we find some correlation at short distances, our swarms are in general only weakly correlated, in contrast to what has been observed in field studies. Our results hint at the potentially important role of environmental conditions on collective behavior, and suggest that general indicators of the collective nature of swarming are still needed.

  3. Control of chironamics in milkfish (Chanos chanos) ponds with Abate (Temephos) insecticide

    Energy Technology Data Exchange (ETDEWEB)

    Tsai, S.C.

    1978-01-01

    Larval chironomids (Chironomus longilobus (Kieffer) are serious competitors with milkfish Chanos chanos (Forskal) for benthic algae in commercial milkfish ponds in Taiwan. Chironomid larvae were effectively killed with temephos (Abate, 0, 0, 0', 0'-tetramethyl 0, 0'-thiodi-p-phenylene phosphorothioate) 50% emulsifiable concentrate when it was diluted 1:2,000 with seawater and applied to milkfish ponds to establish a concentration of 0.050 mg/liter of the active ingredient. This treatment did not harm milkfish and benthic algae. Residues found in the edible portions of milkfish after seven applications of Abate 50% emulsifiable concentrate ranged from 0.02 to 0.08 mg/kg, well below the 1.0 mg/liter approved by the World Health Organization for presence in human drinking water. The acute toxicity of Abate 50% emulsifiable concentrate to 13 other species of aquatic animals was determined in the laboratory.

  4. Emergent dynamics of laboratory insect swarms

    Science.gov (United States)

    Kelley, Douglas H.; Ouellette, Nicholas T.

    2013-01-01

    Collective animal behaviour occurs at nearly every biological size scale, from single-celled organisms to the largest animals on earth. It has long been known that models with simple interaction rules can reproduce qualitative features of this complex behaviour. But determining whether these models accurately capture the biology requires data from real animals, which has historically been difficult to obtain. Here, we report three-dimensional, time-resolved measurements of the positions, velocities, and accelerations of individual insects in laboratory swarms of the midge Chironomus riparius. Even though the swarms do not show an overall polarisation, we find statistical evidence for local clusters of correlated motion. We also show that the swarms display an effective large-scale potential that keeps individuals bound together, and we characterize the shape of this potential. Our results provide quantitative data against which the emergent characteristics of animal aggregation models can be benchmarked.

  5. On the tensile strength of insect swarms

    Science.gov (United States)

    Ni, Rui; Ouellette, Nicholas T.

    2016-08-01

    Collective animal groups are often described by the macroscopic patterns they form. Such global patterns, however, convey limited information about the nature of the aggregation as a whole. Here, we take a different approach, drawing on ideas from materials testing to probe the macroscopic mechanical properties of mating swarms of the non-biting midge Chironomus riparius. By manipulating ground-based visual features that tend to position the swarms in space, we apply an effective tensile load to the swarms, and show that we can quasi-statically pull single swarms apart into multiple daughter swarms. Our results suggest that swarms surprisingly have macroscopic mechanical properties similar to solids, including a finite Young’s modulus and yield strength, and that they do not flow like viscous fluids.

  6. Feeding habits of Solea senegalensis in earthen ponds in Sado estuary

    Science.gov (United States)

    Castelo Branco, Maria Ana; Arruda, Marco A.; Gamito, Sofia

    2010-11-01

    The senegale sole, Solea senegalensis Kaup, 1858, is a commercially valuable fish and it is beginning to be cultured in a semi-intensive way in fish farms in southern European countries. The present study was initiated to investigate the diet of S. senegalensis under semi-extensive conditions. The feeding habits of sole were studied in two earthen ponds of a fish farm in the Sado estuary. In one earthen pond, artificial fish ration was given. S. senegalensis feeds on few prey items, its diet is mainly composed of insect larvae ( Chironomus salinarus) and polychaeta ( Hediste diversicolor). The diet composition of this species suggests feeding specialization, by consuming mainly annelids and insect larvae and by avoiding other items, extremely abundant in the environment, such as gastropods. In the water reservoir where ration was given, some fish consumed simultaneously benthic organism together with ration. However, benthic organisms seem to be the most important component of S. senegalensis diet.

  7. From the Gut of an Insect to the Global Climate: Denitrification and Nitrous Oxide Production inside Lake Chironomidae

    DEFF Research Database (Denmark)

    Stief, Peter; Nielsen, Lars Peter; Revsbech, Niels Peter;

    2006-01-01

    an environmentally relevant ecosystem function by reducing nitrate to dinitrogen gas. Thereby, they remove inorganic nitrogen that originates from organic matter mineralisation and anthropogenic pollution. Nitrous oxide, a greenhouse gas 300 times more potent than carbon dioxide, is emitted from lakes only......FROM THE GUT OF AN INSECT TO THE GLOBAL CLIMATE: DENITRIFICATION AND NITROUS OXIDE PRODUCTION INSIDE LAKE CHIRONOMIDAE P. Stief, L.P. Nielsen, N.P. Revsbech, A. Schramm Department of Biological Sciences, Microbiology, University of Aarhus, Denmark Denitrifying bacteria in lake sediments drive...... and preferential nitrous oxide production are induced. Our investigation indeed revealed the guts of Chironomus plumosus, a widely distributed insect larva, as microsites of microbial denitrification by providing anoxic conditions and enrichment of organic carbon. Both the larvae and their dissected guts emitted...

  8. Organic waste compounds in streams: Occurrence and aquatic toxicity in different stream compartments, flow regimes, and land uses in southeast Wisconsin, 2006–9

    Science.gov (United States)

    Baldwin, Austin K.; Corsi, Steven R.; Richards, Kevin D.; Geis, Steven W.; Magruder, Christopher

    2013-01-01

    -water-indicator compounds, among others. Urban runoff and storm-related leaks of sanitary sewers and (or) septic systems may be important sources of these and other compounds to the streams. The Kinnickinnic River, a highly urbanized site, had the highest detection rates and concentrations of compounds of all the sampled sites. The Milwaukee River near Cedarburg—one of the least urban sites—and the Outer Milwaukee Harbor site had the lowest detection rates and concentrations. Aquatic-toxicity benchmarks were exceeded for 12 of the 25 compounds with known benchmarks. The compounds with the greatest benchmark exceedances were the PAHs, both in terms of exceedance frequency (up to 93 percent for some compounds in sediment samples) and magnitude (concentrations up to 1,024 times greater than the benchmark value). Other compounds with toxicity-benchmark exceedances include Bis(2-ethylhexyl) phthalate (a plasticizer), 2-Methylnapthalene (a component of fuel and oil), phenol (an antimicrobial disinfectant with diverse uses), and 4-Nonylphenol (sum of all isomers; a detergent metabolite, among other uses). Analyzed as a mixture, the suite of PAH compounds were found to be potentially toxic for most non-base-flow samples. Bioassay tests were conducted on samples from 14 streams: Ceriodaphnia dubia in base-flow samples, Ceriodaphnia dubia and Hyallela azteca in pore-water samples, and Hyallela azteca and Chironomus tentans in sediment samples. The greatest adverse effect was observed in tests with Chironomus tentans from sediment samples. The weight of Chironomus tentans after exposure to sediments decreased with increased OWC concentrations. This was most evident in the relation between PAH results and Chironomus tentans bioassay results for the majority of samples; however, solvents and flame retardants appeared to be important for one site each. These results for PAHs were consistent with assessment of PAH potency factors for sediment, indicating that PAHs were likely to have adverse effects

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

    Science.gov (United States)

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

    2015-07-01

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

  10. Searching for effective forces in laboratory insect swarms

    Science.gov (United States)

    Puckett, James G.; Kelley, Douglas H.; Ouellette, Nicholas T.

    2014-04-01

    Collective animal behaviour is often modeled by systems of agents that interact via effective social forces, including short-range repulsion and long-range attraction. We search for evidence of such effective forces by studying laboratory swarms of the flying midge Chironomus riparius. Using multi-camera stereoimaging and particle-tracking techniques, we record three-dimensional trajectories for all the individuals in the swarm. Acceleration measurements show a clear short-range repulsion, which we confirm by considering the spatial statistics of the midges, but no conclusive long-range interactions. Measurements of the mean free path of the insects also suggest that individuals are on average very weakly coupled, but that they are also tightly bound to the swarm itself. Our results therefore suggest that some attractive interaction maintains cohesion of the swarms, but that this interaction is not as simple as an attraction to nearest neighbours.

  11. Sesquiterpenes of the geosmin-producing cyanobacterium Calothrix PCC 7507 and their toxicity to invertebrates.

    Science.gov (United States)

    Höckelmann, Claudia; Becher, Paul G; von Reuss, Stephan H; Jüttner, Friedrich

    2009-01-01

    The occurrence of sesquiterpenes was investigated with the geosmin-producing cyanobacterium Calothrix PCC 7507. The essential oil obtained by vacuum destillation was studied in more detail by GC-MS methods and superposition with authentic compounds. Geosmin was the dominating compound while the other sesquiterpenes were minor components. Sesquiterpenes that have not been described before in cyanobacteria were isodihydroagarofuran, eremophilone and 6,11-epoxyisodaucane. Closed-loop stripping analysis revealed that most of the sesquiterpenes were found in the biomass of Calothrix, while eremophilone was mainly observed in the medium of the axenic culture. Eremophilone showed acute toxicity (LC50) against Chironomus riparius (insecta) at 29 microM and against Thamnocephalus platyurus (crustacea) at 22 microM. The compound was not toxic for Plectus cirratus (nematoda). 6,11-Epoxyisodaucane and isodihydroagarofuran exhibited no toxicity to invertebrates when applied in concentrations up to 100 microM.

  12. Consequences of physical disturbance by tadpoles and snails on chironomid larvae.

    Science.gov (United States)

    Pal, Gargi; Aditya, Gautam; Hazra, Niladri

    2014-01-01

    Indirect interactions among community members impact on organisms. The effects of two snails, banded pond snail, Bellamya bengalensis (Lamarck), and Red-rimmed melania, Melanoides tuberculata (Müller), and tadpoles of Asian common toad, Duttaphrynus melanostictus (Schneider), on nonbiting midge larvae, Chironomus striatipennis Kieffer, were observed in experimental microcosm. Decrease in tube number and tube length of midge larvae was observed compared to control condition due to introduction of selected above mentioned organisms. The direct effects of non-predator organisms on the midge larvae are due to physical disturbance that destroys their tubes. This may result in vulnerability of midge larvae to predators in the wild. So the community structure may be altered by indirect effects, where one or more species, through their direct disturbance, indirectly change the abundance of other species. PMID:24672384

  13. Consequences of Physical Disturbance by Tadpoles and Snails on Chironomid Larvae

    Directory of Open Access Journals (Sweden)

    Gargi Pal

    2014-01-01

    Full Text Available Indirect interactions among community members impact on organisms. The effects of two snails, banded pond snail, Bellamya bengalensis (Lamarck, and Red-rimmed melania, Melanoides tuberculata (Müller, and tadpoles of Asian common toad, Duttaphrynus melanostictus (Schneider, on nonbiting midge larvae, Chironomus striatipennis Kieffer, were observed in experimental microcosm. Decrease in tube number and tube length of midge larvae was observed compared to control condition due to introduction of selected above mentioned organisms. The direct effects of non-predator organisms on the midge larvae are due to physical disturbance that destroys their tubes. This may result in vulnerability of midge larvae to predators in the wild. So the community structure may be altered by indirect effects, where one or more species, through their direct disturbance, indirectly change the abundance of other species.

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

    Science.gov (United States)

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

    2015-07-01

    The present study was performed to investigate the toxicity of fluoride to a variety of freshwater aquatic organisms and to establish whether water quality variables contribute substantively to modifying its toxicity. Water hardness, chloride, and alkalinity were tested as possible toxicity modifying factors for fluoride using acute toxicity tests with Hyalella azteca and Oncorhynchus mykiss. Chloride appeared to be the major toxicity modifying factor for fluoride in these acute toxicity tests. The chronic toxicity of fluoride was evaluated with a variety of species, including 3 fish (Pimephales promelas, O. mykiss, and Salvelinus namaycush), 3 invertebrates (Ceriodaphnia dubia, H. azteca, and Chironomus dilutus), 1 plant (Lemna minor), and 1 alga (Pseudokirchneriella subcapitata). Hyalella azteca was the most sensitive species overall, and O. mykiss was the most sensitive species of fish. The role of chloride as a toxicity modifying factor was inconsistent between species in the chronic toxicity tests. PMID:25732700

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

    Science.gov (United States)

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

    2009-07-01

    Bisphenol A (BPA, 4,4'-isopropylidine diphenol) is a commercially important chemical used primarily as an intermediate in the production of polycarbonate plastic and epoxy resins. Extensive effect data are currently available, including long-term studies with BPA on fish, amphibians, crustaceans, and mollusks. The aim of this study was to perform additional tests with a number of aquatic invertebrates and an aquatic plant. These studies include acute tests with the midge (Chironomus tentans) and the snail (Marisa cornuarietis), and chronic studies with rotifers (Brachionus calyciflorus), amphipods (Hyalella azteca), and plants (Lemna gibba). The effect data on different aquatic invertebrate and plant species presented in this paper correspond well with the effect and no-effect concentrations (NOECs) available from invertebrate studies in the published literature and are within the range found for other aquatic species tested with BPA. PMID:19327838

  16. [Mode of formation of the flight muscles in a nematocerous Diptera].

    Science.gov (United States)

    Lebart-Pedebas, M C; Auber, J

    1982-01-01

    An electron microscope study was conducted on the origin of the dorsal longitudinal muscles of a Nematocerous Diptera (Chironomus). These imaginal muscles arise from three pairs of slender larval muscles that are characterized by the presence of myoblasts located beneath the basal lamina and adhering to the sarcoplasmic membrane. During the last larval instar the myoblasts increase in number, each of the associated muscle fibers loses its contractile material and splits longitudinally into two to form six columns of sarcoplasm. Differentiation of the fibrillar material begins in each of the six muscle rudiments after the adhering myoblasts have become incorporated. There are several possible origins for these myoblasts: they may be embryonic cells that persist in association with the larval muscle fibers; or --as in the case of Cyclorrhaphous Diptera-- they may migrate from elsewhere to invest these fibers. PMID:7138012

  17. On the tensile strength of insect swarms.

    Science.gov (United States)

    Ni, Rui; Ouellette, Nicholas T

    2016-01-01

    Collective animal groups are often described by the macroscopic patterns they form. Such global patterns, however, convey limited information about the nature of the aggregation as a whole. Here, we take a different approach, drawing on ideas from materials testing to probe the macroscopic mechanical properties of mating swarms of the non-biting midge Chironomus riparius. By manipulating ground-based visual features that tend to position the swarms in space, we apply an effective tensile load to the swarms, and show that we can quasi-statically pull single swarms apart into multiple daughter swarms. Our results suggest that swarms surprisingly have macroscopic mechanical properties similar to solids, including a finite Young's modulus and yield strength, and that they do not flow like viscous fluids. PMID:27559838

  18. Effects of nitrate addition on phosphorus retention in an eutrophic reservoir : laboratory experiments

    International Nuclear Information System (INIS)

    The Ibrite reservoir in southeast Brazil is polluted with effluents from an oil refinery as well as domestic untreated sewage from cities in the region. In this study, calcium nitrate was used as a sediment remediation technology in order to reduce phosphorus availability. Experiments were conducted in microcosms incubated for up to 135 days. Ceriodaphnia silvestrii and Vibrio fisheri were used to conduct an acute toxicity assessment of the water column and pore water of the sediments. Chironomus xanthus was used to assess bulk sediments. Results of the chemical analyses showed that high values of acid volatile sulfide in the sediments decreased by 99 per cent after 135 days of incubation. Approximately 50 per cent of the soluble reactive phosphorus was removed from the water column. The toxicity of the tested organisms was attributed to high nitrate concentrations in pore water sediments. Results indicated that calcium nitrate is not suitable as a sediment remediation technology.

  19. Potential ecological risk of heavy metal contamination in sediments and macrobenthos in coastal wetlands induced by freshwater releases: A case study in the Yellow River Delta, China.

    Science.gov (United States)

    Li, Ming; Yang, Wei; Sun, Tao; Jin, Yuwan

    2016-02-15

    We investigated the nine heavy metal contents in the sediments and macrobenthos of the Yellow River Delta Wetlands using three experimental areas that received freshwater releases and one reference area that did not. Heavy metal contents, the single-factor contamination index (SFCI), the metal contamination index (MCI), and the biota-sediment accumulation factor (BSAF) were used to evaluate the potential ecological risk and bioaccumulation. We found that As exceeded the national standard value by more than 50%, and that the ranges of SFCI for each metal were generally larger in autumn than in spring. MCI showed no clear pattern, but the BSAF results suggest that Cd bioaccumulates from sediments to macrobenthos. Pollution-resistant species such as Corophium sinense, Chironomus sp., and Einfeldia sp. became dominant in the areas receiving freshwater releases, and provide direct evidence of ecological risk in the wetlands. Our results provide preliminary information to guide managers for ecological risk assessments. PMID:26719069

  20. Distribution of chironomidae (Insecta: Diptera) in polluted rivers of the Juru River Basin, Penang, Malaysia.

    Science.gov (United States)

    Al-Shami, Salman A; Rawi, Che Salmah Md; HassanAhmad, Abu; Nor, Siti Azizah Mohd

    2010-01-01

    The influence of physical and chemical parameters on the abundance and diversity of chironomids was studied in six rivers with moderate to highly polluted water in the Juru River Basin. The rivers: Ceruk Tok Kun (CTKR) as reference site, and polluted rivers of Pasir (PR), Juru (JR), Permatang Rawa (PRR), Ara (AR) and Kilang Ubi (KUR) were sampled over a period of five months (November 2007-March 2008). Nine chirnomid species: Chironimus kiiensis, C. javanus, Polypedilum trigonus, Microchironomus sp., Dicrotendipes sp., Tanytarsus formosanus, Clinotanypus sp., Tanypus punctipennis and Fittkauimyia sp. were identified. Assessment of their relationships with several environmental parameters was performed using the canonical correspondence analysis (CCA). Tanytarsus formosanus was the most dominant in the relatively clean CTKR and moderately polluted JR with mean densities of 19.66 and 25.32 m(-2), respectively while C. kiiensis was abundant in more polluted rivers. Tanytarsus formosanus, Dicrotendipes sp. and Microchironomus sp. were grouped under moderate to high water temperature, total organic matter (TOM), total suspended solids (TSS), velocity, pH, phosphates and sulphates. However, Tanypus punctipennis, Fittkauimyia sp., and Clinotanypus sp. were associated with high contents of river sediment such as TOM, Zn and Mn and water ammonium-N and nitrate-N and they were associated with higher dissolved oxygen (DO) content in the water. Chironomus kiiensis, C. javanus and P. trigonus showed positive relationships with TOM, ammonium-N and nitrate-N as well as trace metals of Zn, Cu and Mn. These three species could be considered as tolerant species since they have the ability to survive in extreme environmental conditions with low DO and high concentrations of pollutants. Based on the water parameter scores in all rivers, the highest diversity of chironomid larvae was reported in CTKR. With higher concentrations of organic and/or inorganic pollutants as reported in PPR

  1. Effects of cadmium and resource quality on freshwater detritus processing chains: a microcosm approach with two insect species.

    Science.gov (United States)

    Campos, Diana; Alves, Artur; Lemos, Marco F L; Correia, António; Soares, Amadeu M V M; Pestana, João L T

    2014-07-01

    Detritus processing is vital for freshwater ecosystems that depend on the leaf litter from riparian vegetation and is mediated by microorganisms and aquatic invertebrates. Shredder invertebrates transform coarse particulate organic matter into fine particulate organic matter used as food by collector species. Direct and indirect effects of contaminants can impair detritus processing and thus affect the functioning of these ecosystems. Here, we assessed the combined effects of a toxic metal (cadmium) and resource quality (leaf species) on detritus processing and shredder-collector interactions. We considered two types of leaves, alder and eucalyptus that were microbially conditioned under different Cd concentrations in the laboratory. The microbial communities present on leaves were analyzed by Denaturing Gradient Gel Electrophoresis (DGGE), and we also measured microbial respiration rates. Sericostoma vittatum (a caddisfly shredder) and Chironomus riparius (a midge collector) were also exposed to Cd and allowed to consume the corresponding alder or eucalyptus leaves. We evaluated C. riparius growth and leaf mass loss in multispecies microcosms. Cadmium exposure affected leaf conditioning and fungal diversity on both leaf species, as assessed by DGGE. Cadmium exposure also affected the mass loss of alder leaves by reductions in detritivore feeding, and impaired C. riparius growth. Chironomus riparius consumed alder leaf discs in the absence of shredders, but S. vittatum appear to promote C. riparius growth in treatments containing eucalyptus. These results show that indirect effects of contaminants along detritus-processing chains can occur through effects on shredder-collector interactions such as facilitation but they also depend on the nutritional quality of detritus and on sensitivity and feeding plasticity of detritivore species. PMID:24648031

  2. Factors Influencing the Stable Oxygen and Hydrogen Isotopic Composition (δ 18O and δ D) of a Subarctic Freshwater Lake Ecosystem

    Science.gov (United States)

    Wang, Y.; Wooller, M. J.

    2005-12-01

    Previous studies have shown that the stable oxygen and hydrogen isotopic compositions (δ 18O and δD) in various animal tissues can be used to examine past climates and animal migration pattern. Little attention has been paid to the relative roles of diet and water influencing the overall δ 18O and δD of animal tissues in freshwater ecosystems. It is unclear whether different trophic levels in a freshwater lake ecosystem have an identical relationship to the water that surrounds them. The δ18O and δD values of animal tissues may be controlled by numerous different factors, including metabolic and biosynthetic isotopic fractionation and variations of δ 18O and δD in the food available. We began to examine these issues by analyzing the δ 18O and δD throughout a freshwater aquatic ecosystem at Smith Lake in Alaska. We collected samples representing primary producers and consumers (primary and secondary). Samples included green algae, various aquatic plants, such as Nuphar variegatum (water lily), Polygonum amphibium (water smartweed), Carex utriculata (sedge), Utricularia vulgaris (common bladderwort), Typha latifolia (common cattail), and a range of aquatic invertebrates, including Chironomus. sp (midge), Zygoptera (damselfly), Anisoptera (dragonfly), Dytiscidae (diving beetle) and Euhirudinea (leeches). The δ 18O and δD of Smith Lake water were ~-13.5e and -129.0e, respectively, and we present the δ 18O and δD of the rest of the ecosystem relative to these data. For instance, the δ 18O of chironomus sp. was ~12.1, which is greater than the of the lake water. Preliminary results suggest the extent of the fractionation between δ 18O of chironomids vs. lake water δ 18O is consistent with previous studies. Our data provide an insight into the range of variations that could be expected within a single freshwater ecosystem.

  3. Morfologia e morfometria da traqueia da preguiça (Bradypus variegatus: conhecimentos para procedimentos de emergência

    Directory of Open Access Journals (Sweden)

    Thamirys A.S. Faro

    2015-02-01

    Full Text Available Por ser uma espécie pouco estudada, principalmente do ponto de vista morfológico, objetivou-se conhecer a anatomia da traqueia da preguiça (Bradypus variegatus a fim de fornecer informações para facilitar a eleição de tubo endotraqueal adequado, máscara laríngea ou cânula de traqueostomia para anestesia e procedimentos de emergência, uma vez que a mesma revelou-se possuidora de uma morfologia especial. Foram investigados 11animais jovens de idades diferentes, sendo quatro machos e sete fêmeas, provenientes do Museu Emilio Goeldi e doados a UFRA. Os exemplares foram perfundidos via intramuscular com solução aquosa de formol a 10% para fins de conservação e posteriormente foram dissecados em nível cervico-torácico, por meio de mesoscopia, expondo-se desde a laringe até os brônquios principais direito e esquerdo ao nível do hilo pulmonar. As traqueias foram divididas em cinco regiões (região cervical, região da primeira flexura, região da segunda flexura, região da terceira flexura e região da carina as quais foram mensuradas altura e largura, assim como o comprimento traqueal total e parte do material foi submetido à técnicas de rotina histológica. Macroscopicamente, destacou-se a presença de sinuosidades acentuadas em porção médio caudal, contemplando a carina. O comprimento médio traqueal foi de 14,6cm. Microscopicamente, a traqueia era constituída por placas separadas de cartilagem hialina constituindo cada anel, sendo revestido por epitélio estratificado ciliado. Apesar da traqueia da preguiça comum apresentar revestimento padrão encontrado na traqueia de outros animais, na literatura não há registros de outras espécies que tenham morfologia macroscópica nas condições descritas, o que nos leva a sugerir, quando necessário acesso para ventilação de emergência, a prática da IOT e não a de traqueostomia.

  4. Collecting and evaluation of germplasm of spiked pepper from Brazilian Amazon Pimenta-de-macaco: coleta e avaliação de germoplasma na Amazônia Brasileira

    Directory of Open Access Journals (Sweden)

    José Maria D Gaia

    2010-06-01

    Full Text Available Spiked pepper (Piper aduncum L. is an aromatic plant species with high essential oil production. It is a species that occurs abundantly in the Brazilian Amazon. Its essential oil has exploitable biological properties in the human health and agriculture. Aiming to study its germplasm toward future use in genetic breeding programs, collecting was carried out (inflorescences, cuttings, leaves and thin branches in ten provenances from the Brazilian Amazon. Twelve morphoagronomic traits were determined to take the data: number of leaves by branch, length of leaf, width of the leaf, circumference of the older branch, height of the plant, number of orthotropic branches, number of plageotropic branches, length of the internodes, number of spikes per branches, yielding of oil, content and production of dillapiole, as well as data on the environment and populations of spiked pepper. The inflorescences and cuttings were encoded and sent for the Federal Rural University from Pará State (UFRA, Brazil, for propagation. The leaves and thin branches were sent for the Emílio Goeldi Museum, from Pará State (MPEG for extraction of essential oil (hydrodistillation. Estimators of amplitude of variation, mean, standard deviation and coefficient of variation were utilized to study the phenotypical variability. The morphoagronomic traits of largest variability were number of orthotropic branches, number of spikes per branch, circumference of the older branch and the content and production of dillapiole. This species has adapted to many different environments of vegetation, soil, climate, relief and drainage becomming easy the domestication and cropping. There is morphoagronomic variability pleasing the selection and genetic breeding.Piper aduncum L. é uma planta que ocorre na Amazônia Brasileira com elevado teor de óleo essencial e que apresenta propriedades biológicas utilizáveis na agricultura e saúde humana. Com o objetivo de avaliar germoplasma visando ao

  5. Efeito de isolados de Paecilomyces lilacinus no desenvolvimento de cafezais e na população de Meloidogyne paranaensis Effect of isolates of Paecilomyces lilacinus on the development of coffee plantations and on the population of Meloidogyne paranaensis

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    Marina Capparelli Cadioli

    2009-06-01

    Full Text Available Com a finalidade de diminuir as perdas causadas pelos nematóides do gênero Meloidogyne (Goeldi, 1887 na cultura do cafeeiro, dentre as diversas medidas de manejo, o controle biológico com o fungo Paecilomyces lilacinus (Thom., 1910 Samson, 1974 se destaca como uma alternativa de controle vantajosa, quer dos pontos de vista ecológico ou econômico. Assim, neste trabalho, objetivou-se avaliar a eficiência de 10 isolados de Paecilomyces lilacinus no controle de Meloidogyne paranaensis em cafeeiro (Coffea arabica L. cv. Icatú, em casa-de-vegetação. No experimento I, as mudas de cafeeiro foram transplantadas em solo onde foram, anteriormente, cultivados tomateiros para multiplicação de M. paranaensis mais 50 g de arroz colonizado com os 10 isolados. No segundo experimento, mudas de cafeeiro foram transplantadas para substrato solo e areia (1:1 juntamente com 50 g de arroz colonizado com os isolados. Em seguida, as mudas foram inoculadas com ± 5000 ovos de M. paranaensis. Nos dois experimentos, após 15 dias procedeu-se aplicação por cobertura de 50 g dos isolados. O delineamento foi inteiramente casualizado com 12 tratamentos. Após 90 dias, foram feitas as avaliações. Os isolados de P. lilacinus não afetaram o diâmetro do caule de cafeeiro. No experimento I, os isolados Pae 22, 24 e 28 promoveram o crescimento dos cafeeiros; todos os isolados reduziram a população de ovos no sistema radicular; e os isolados Pae 3 e 12 reduziram a população de J2 de M. paranaensis no solo. No experimento II, os isolados Pae 03, 10, 12 e 13 favoreceram o crescimento das plantas, mas reduziram o peso fresco do sistema radicular; todos os isolados reduziram a população de J2 no solo; e os isolados Pae 3, 10, 13, 18, 22 e 24 reduziram as malformações causadas por M. paranaensis nas raízes.In order to reduce the losses caused by nematodes of the genus Meloidogyne (Goeldi, 1887 in coffee plantation, among several management measures, biological

  6. Florística e estrutura do estrato arbóreo de uma floresta de várzea no município de Santa Bárbara do Pará, Estado do Pará, Brasil Floristic and structure of tree communities in the floodplain forest on municipallity of Santa Bárbara do Pará, State of Pará, Brazil

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    Gideão Costa dos Santos

    2006-12-01

    Full Text Available Este estudo teve como objetivo conhecer a composição florística e a estrutura do estrato arbóreo de uma floresta de várzea na localidade de São José do Aracy, no município de Santa Bárbara do Pará, estado do Pará, Brasil. Foram instaladas quatro parcelas de 100 x 100 m subdivididas em cinco transectos de 20 x 100 m e foram amostradas as espécies arbóreas lenhosas e palmeiras. Para as espécies lenhosas adotou-se diâmetro à altura do peito (DAP ³ 10cm e para palmeiras a circunferência à altura do peito (CAP ³ 10cm e estimou-se a altura. O material botânico coletado foi identificado em nível de família, gênero e espécie, sendo incorporado ao herbário João Murça Pires do Museu Paraense Emílio Goeldi (MPEG. Na análise fitossociológica foram calculados os parâmetros de Densidade Relativa (DR%, Freqüência Relativa (FR%, Dominância Relativa (DOMR%, Índice de Valor de Importância (IVI, Índice de Valor de Cobertura (IVC, Índice de similaridade de Sorenson (S', Índice de diversidade de Shannon (H' e Equabilidade (E'. Os resultados mostraram 29 famílias, 58 gêneros e 70 espécies. As famílias com maior diversidade foram Caesalpiniaceae, Mimosaceae e Papilionaceae, com nove, oito e sete espécies, respectivamente; Arecaceae e Papilionaceae obtiveram maior densidade (27,75% e 25,84%; treze famílias foram mais freqüentes com 4,88% entre elas; Papilionaceae com maior dominância e índice de valor de importância (37,50% e 68,21; Euterpe oleracea Mart. apresentou maior densidade relativa e Pterocarpus officinalis Jacq., maior dominância relativa, maior índice de valor de importância e de cobertura. O índice de diversidade de 2,63 foi considerado baixo, com equabilidade de 0,63 e similaridade de 0,60. A várzea estudada apresentou baixa diversidade em espécies.This research has taken place in four of 100 x 100 m in São José do Aracy, in the municipallity of Santa Bárbara do Pará, State of Pará, Brazil. Each

  7. Efeito de indutores de resistência sobre Meloidogyne exigua do cafeeiro Effect of resistance inducers on Meloidogyne exígua of coffee

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    Sônia Maria de Lima Salgado

    2007-08-01

    Full Text Available A possibilidade de manejo de Meloidogyne exigua Goeldi, 1887, pela ativação de mecanismos de defesa no cafeeiro representa uma alternativa potencialmente útil no manejo desse patógeno. Com este trabalho, objetivou-se avaliar a eclosão e mortalidade de juvenis do segundo estádio (J2 de M. exigua na presença de produtos indutores de resistência e avaliar o efeito do acibenzolar-S-metil (ASM, Bion® na indução de resistência do cafeeiro (Coffea arabica L. 'Catuaí- 144' contra M. exigua. A eclosão e mortalidade do J2 foram avaliadas no ASM e ácido salicílico (AS nas dosagens de 0,2; 0,35 e 0,5 g. i. a./L; e no fosfito de potássio (Hortifós® PK e silicato de potássio (Supa-potássio® nas dosagens 5,0; 7,5 e 10,0 mL/L, empregando água e aldicarbe como testemunhas. No segundo ensaio o ASM (0,2 g i.a./L foi aplicado na quantidade de 125 mL por planta de 'Catuaí-144' com um ano de idade, via pulverização foliar e diretamente ao solo aos 7 dias antes da inoculação e aos 2 e 7 dias após a inoculação de aproximadamente 7000 ovos de M. exigua/planta. Foram utilizadas 8 plantas/tratamento/bloco, totalizando 6 tratamentos (3 épocas de aplicação do ASM, testemunhas absoluta e inoculada, em 4 blocos. Aos 90 dias da inoculação, foi feita a avaliação da população final (número de ovos e juvenis de M. exigua, número de galhas, fator de reprodução (população final/população inicial e peso da matéria fresca da raiz. A dosagem dos produtos não influenciou a eclosão e mortalidade dos J2 de M. exigua. Menor eclosão dos J2 de M. exigua ocorreu igualmente no Supa-potássio® e ácido salicílico, enquanto que a eclosão no ASM e na água foi igual (P The parasitism of coffee roots by Meloidogyne exigua Goeldi, 1887, widespread nematode in the main producing regions, can provoke a series of modifications in the normal development of the plant. The induction of resistance for the activation of existing latent mechanisms of

  8. Ecotoxicological sediment survey of large German rivers; Oekotoxikologische Sedimentkartierung der grossen Fluesse Deutschlands

    Energy Technology Data Exchange (ETDEWEB)

    Duft, M.; Tillmann, M. [Internationales Hochschulinstitut Zittau (Germany); Oehlmann, J. [Frankfurt Univ. (Germany). Zoologisches Inst., Abt. Oekologie und Evolution

    2003-05-01

    In this project, a nation-wide, ecotoxicologically-based sediment survey was carried out. For this purpose, a total of about 200 sediment samples from 12 selected large German rivers (Danube, Elbe, Ems, Main, Mosel, Neckar, Neisse, Odra, Rhine, Ruhr, Saar and Weser) were analysed with regard to abiotic parameters (heavy metals, PAH, organic carbon content, particle size) and also by means of two biological test systems with benthic invertebrates (nematode test with the roundworm Caenorhabditis elegans and chironomid test with the non-biting midge Chironomus riparius). Subsequently, this comprehensive data set was analysed statistically. By means of an iterative method, a five-stage, statistically-derived assessment concept which is founded on the results of the biological tests, was developed following the EU water framework directive. In general, the classification with the nematode test turned out to be the more sensitive method. A principal component analysis and correlations showed that the parameters of both biotests provide different information which suggests a combined use of both tests. Correlations also indicate a connection of biotest results and abiotic parameters (organic carbon content, particle size and heavy metal contamination). (orig.) [German] Im Projekt wurde eine bundesweite oekotoxikologische Sedimentkartierung grosser Fliessgewaesser durchgefuehrt. Dazu wurden insgesamt etwa 200 Sedimentproben aus 12 ausgewaehlten grossen Fluessen Deutschlands (Donau, Elbe, Ems, Main, Mosel, Neckar, Neisse, Oder, Rhein, Ruhr, Saar und Weser) auf ihre abiotischen Parameter (Schwermetalle, PAK, organischer Kohlenstoffgehalt, Korngroesse) hin analysiert sowie mit zwei biologischen Testverfahren mit benthischen Invertebraten (Nematodentest mit dem Fadenwurm Caenorhabditis elegans und Chironomidentest mit der Zuckmuecke Chironomus riparius) untersucht. Dieses umfangreiche Datenmaterial wurde anschliessend statistisch ausgewertet und mit Hilfe eines iterativen

  9. Avaliação rápida da integridade ecológica em riachos urbanos na bacia do rio Corumbá no Centro-Oeste do Brasil

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    Giovanna Gomes Cordeiro

    2016-06-01

    Full Text Available A urbanização tem ocasionado o lançamento de volumes significativos de efluentes domésticos parcialmente tratados nos corpos hídricos brasileiros causando diversos prejuízos ecológicos para estes ecossistemas. Para avaliar a integridade ecológica de riachos na região de Cerrado do Brasil Central foram selecionados quatro pontos de coleta, considerando o nível de influência antrópica ao qual estão submetidos. Foram analisados parâmetros físicos e químicos da água, o uso da paisagem e a comunidade de macroinvetebrados bentônicos. As coletas foram realizadas em julho de 2015 e foram mensuradas "in situ" as variáveis condutividade elétrica, temperatura da água, pH, oxigênio dissolvido, turbidez, largura e comprimento do riacho e velocidade da correnteza. Em seguida, foram coletadas amostras para o seston, perifíton, macroinvertebrados bentônicos e sedimento depositado. O ponto "Referência" apresentou menor abundância de larvas de Chironomus (Chironomidae: Diptera e maior riqueza taxonômica, além de maior abundância dos grupos taxonômicos Ephemeroptera, Plecoptera e Trichoptera, mostrando ser o sistema mais íntegro dentre os analisados. A sub-bacia delimitada a partir desse ponto mostrou uma maior porcentagem de áreas com vegetação nativa (51%. Os pontos com presença de efluentes domésticos ("ETE" e "Jusante" por sua vez, apresentaram valores mais elevados de condutividade elétrica, turbidez, maior abundância de larvas de Chironomus e menor riqueza de táxons, mostrando elevado impacto em função das atividades antrópicas. A avaliação rápida realizada com a composição da comunidade bentônica e as variáveis físicas e químicas da água foi suficiente na identificação das alterações na integridade ecológica causadas pela influência antrópica na bacia hidrográfica do rio Corumbá.

  10. Toxicity on aquatic organisms exposed to secondary effluent disinfected with chlorine, peracetic acid, ozone and UV radiation.

    Science.gov (United States)

    da Costa, Juliana Berninger; Rodgher, Suzelei; Daniel, Luiz Antonio; Espíndola, Evaldo Luiz Gaeta

    2014-11-01

    The toxic potential of four disinfectant agents (chlorine, ozone, peracetic acid and UV radiation), used in the disinfection of urban wastewater, was evaluated with respect to four aquatic organisms. Disinfection assays were carried out with wastewater from the city of Araraquara (São Paulo State, Brazil), and subsequently, toxicity bioassays were applied in order to verify possible adverse effects to the cladocerans (Ceriodaphnia silvestrii and Daphnia similis), midge larvae Chironomus xanthus and fish (Danio rerio). Under the experimental conditions tested, all the disinfectants were capable of producing harmful effects on the test organisms, except for C. xanthus. The toxicity of the effluent to C. silvestrii was observed to increase significantly as a result of disinfection using 2.5 mg L(-1) chlorine and 29.9 mg L(-1) ozone. Ozonation and chlorination significantly affected the survival of D. similis and D. rerio, causing mortality of 60 to 100 % in comparison to the non-disinfected effluent. In experiments with effluent treated with peracetic acid (PAA) and UV radiation, a statistically significant decrease in survival was only detected for D. rerio. This investigation suggested that the study of the ideal concentrations of disinfectants is a research need for ecologically safe options for the treatment of wastewater.

  11. Assessment of the ecological effects of arsenic on a southern Ohio, USA stream.

    Science.gov (United States)

    Huddleston, George M; Dorn, Philip B; Gillespie, W Barry; Wong, Diana C L; Slocomb, John P

    2009-04-01

    Davis Creek is a southern Ohio, USA stream that receives a permitted discharge from the Belpre Elastomers Plant (BEP). A sediment quality triad investigation of Davis Creek was conducted over a 2-y period that included sediment and surface water chemistry measurements, toxicity tests of whole sediment, interstitial and surface water, and benthic and artificial substrate community assessments. The concentration of arsenic in surface and interstitial water was below United States Environmental Protection Agency ambient water quality criteria and was not toxic in laboratory tests (Ceriodaphnia dubia, Pimephales promelas). Similarly, sediments did not significantly affect survival and growth of Hyalella azteca and Chironomus tentans at most sampling locations despite sediments exceeding arsenic sediment screening values in nearly all samples collected. Differences in benthic community structure, determined by rapid bioassessment and Hester-Dendy sampling methods, were related primarily by variations in sediment moisture, particle size, and ammonia and not to arsenic concentrations. The Invertebrate Community Index (ICI) for Davis Creek was lower than values established for other warm-water ecoregional reference streams in Ohio. However, this ICI comparison may have been invalid because, unlike the reference streams, the Davis Creek watershed is small with intermittent headwater flow that limits macroinvertebrate recruitment and energy input. The sediment quality triad investigation indicated that Davis Creek was not significantly affected by arsenic associated with the BEP discharge despite having measured arsenic concentrations that exceeded sediment screening values. PMID:19055317

  12. Preliminary Study of Phylogenetic Relationship of Rice Field Chironomidae (Diptera Inferred From DNA Sequences of Mitochondrial Cytochrome Oxidase Subunit I

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    Salman A. Al-Shami

    2009-01-01

    Full Text Available Problem statement: Chironomidae have been recorded in rice fields throughout the world including in many countries such as India, Australia and the USA. Although some studies provide the key to genera level and note the difficulty of identifying the larvae to species level. Chironomid researches have been hindered because of difficulties in specimen preparation, identification, morphology and literature. Systematics, phylogenetics and taxonomic studies of insects developed quickly with emergence of molecular techniques. These techniques provide an effective tool toward more accurate identification of ambiguous chironomid species. Approach: Samples of chironomids larvae were collected from rice plots at Bukit Merah Agricultural Experimental Station (BMAES, Penang, Malaysia. A 710 bp fragment of mitochondrial gene Cytochrome Oxidase subunit I (COI was amplified and sequenced. Results: Five species of Chironomidae; three species of subfamily Chironominae, Chironomus kiiensis, Polypedilum trigonus, Tanytarsus formosanus, two species of subfamily Tanypodinae, Clinotanypus sp and Tanypus punctipennis were morphologically identified. The phylogenetic relationship among these species was been investigated. High sequence divergence was observed between two individuals of the presumed C. kiiensis and it is suggested that more than one species may be present. However the intraspecific sequence divergence was lower between the other species of Tanypodinae subfamily. Interestingly, Tanytarsus formosanus showed close phylogenetic relationship to Tanypodinae species and this presumably reflect co-evolutionary traits of different subfamilies. Conclusion: The sequence of the mtDNA cytochrome oxidase subunit I gene has proven useful to investigate the phylogenetic relationship among the ambiguous species of chironomids.

  13. Assimilation efficiencies of Cd and Zn in the common carp (Cyprinus carpio): Effects of metal concentration, temperature and prey type

    International Nuclear Information System (INIS)

    The impact of several factors on the assimilation efficiency (AE) of Cd and Zn from food in the common carp (Cyprinus carpio) was studied. Tested prey species were midge larvae (Chironomus riparius), zebra mussels (Dreissena polymorpha) and oligochaetes (Tubifex tubifex). The Cd load of the larvae did not affect the Cd AE in the carp. The Zn AE however, was negatively related to the Zn load of the prey. Food quantity and starvation of the carp did not significantly affect the Cd AE. For Zn, a significant decrease in AE was found when carp were fed ad libitum. Decreasing the temperature from 25 oC to 15 oC did not influence the Cd AE, while for Zn a significant decrease of the AE was measured. Carp assimilated Cd from both zebra mussels and oligochaetes with a significantly lower efficiency in comparison to the midge larvae, although Zn AEs was prey independent. - Assimilation efficiency of Cd and Zn in food of carp is affected by metal load, prey type and temperature

  14. Factors affecting decomposition rates of chironomid (Diptera pupal exuviae

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    Rathi G. Kavanaugh

    2014-12-01

    Full Text Available Collections of floating chironomid pupal exuviae are used to monitor water quality and assess ecological conditions. Factors controlling exuviae sinking rates are not well known, although they should have an effect on conclusions that can be drawn from collections. The current study was conducted to determine the rate of sinking under controlled laboratory conditions using water from three streams with different nutrient levels. Sinking rates ranged from less than a day to seven days, depending on microbial activity, nutrient concentrations, temperature and turbulence. Results also varied by genus, with pupal exuviae of Chironomus riparius, Diamesa nivoriunda, Orthocladius (Euorthocladius thienemanni and Eukiefferiella sp. used in experiments. Four species of bacteria and eight genera of fungi colonized and metabolized exuviae, with bacteria dominant early and fungi dominant later in the decomposition process. Decomposition was faster in lightly chitinized abdominal conjunctive areas, which resulted in exuviae breaking apart and sinking. Examination of untreated, dewaxed and dewaxed-deproteinized exuviae indicated that untreated exuviae sank faster. Waxes appeared important for colonization and initial microbial metabolization was delayed when waxes were removed. Results confirm the importance of biological degradation of exuviae in determining floatation times. We predict that streams and other waterbodies with high dissolved nutrients will result in rapidly sinking exuviae, while exuviae in low nutrient waterbodies will float longer.Article submitted 1. October 2014, accepted 18. November 2014, published 22. December 2014.

  15. Toxicity of carbon nanotubes to freshwater aquatic invertebrates

    Science.gov (United States)

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

    2012-01-01

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

  16. Occurrence and Population Dynamics of Chironomids in Early-Season Rice Fields

    Institute of Scientific and Technical Information of China (English)

    LI Zhi-yu; YANG Hong; LAI Feng-xiang; FU Qiang; HU Yang

    2011-01-01

    The chironomid is one of the world wide distributed insects and normally occurs in a great abundance among many kinds of water bodies.Currently,our knowledge about the chironomid in rice fields is limited to the species survey,and it is considered as a group insect at the family level,termed as a kind of the neutral insects.By using the specially designed emergence traps,the species richness and the occurrence of the chironomid in rice fields were studied throughout the early season in Fuyang City,Zhejiang Province,China.There were four species,namely,Tanytarsus formosanus,Chironomus sinicus,Polypedilum nubifer and Tanypus punctipennis of chironomids collected from rice fields.All of them are widely distributed species.T.formosanus and C.sinicus were the most dominant species in rice fields.The succession of chironomids in the early season could be divided into two phases,the early and the late phases.The abundance of the chironomid was higher in the early phase than that in the late phase.It was estimated that there were around 3 million individuals of chironomids emerged from 667 m2 rice field throughout the early season.It was also found that the sex ratio of T.formosanus was female-biased during the early phase,whereas male-biased during the late phase.In contrast,the sex ratio of C.sinicus was male-biased throughout the early season.

  17. Impact of a flood disaster on sediment toxicity in a major river system - the Elbe flood 2002 as a case study

    International Nuclear Information System (INIS)

    The ecotoxicological implications of a flooding disaster were investigated with the exceptional Elbe flood in August 2002 as an example. Sediment samples were taken shortly after the flood at 37 sites. For toxicity assessment the midge Chironomus riparius (Insecta) and the mudsnail Potamopyrgus antipodarum (Gastropoda) were exposed to the sediment samples for 28 days. For a subset of 19 sampling sites, the contamination level and the biological response of both species were also recorded before the flood in 2000. The direct comparison of biological responses at identical sites revealed significant differences for samples taken before and immediately after the flood. After flood sediments of the river Elbe caused both higher emergence rates in the midge and higher numbers of embryos in the mudsnail. Contrary to expectations the toxicity of the sediments decreased after the flood, probably because of a dilution of toxic substances along the river Elbe and a reduction in bioavailability of pollutants as a result of increasing TOC values after the flood. - The extraordinary Elbe flood in August 2002 did not result in an overall increase of environmental contamination

  18. Mosquito larvicidal and biting deterrency activity of bud of Polianthes tuberosa plants extract against Anopheles stephensi and Culex quinquefasciatus.

    Science.gov (United States)

    Anjali, Rawani; Atanu, Banerjee; Goutam, Chandra

    2012-06-01

    Mosquito control by phytochemicals is an alternative method to synthetic insecticides, as it is biodegradable and non resistant to vector mosquito. Polianthes tuberosa is a perennial plant distributed in many parts of India. The present study was undertaken to scientifically evaluate the larvicide and biting deterrency activity of bud of Polianthes tuberosa against Culex quinquefasciatus and Anopheles stephensi. Crude and solvent extract [ethyl acetate, chloroform: methanol (1:1, v/v), acetone] of fresh, mature, bud of P. tuberosa was tested against (ex. quinquefasciatus and An. stephensi. The repellent activity tested by chloroform: methanol (1:1, v/v) solvent extract against both mosquito species. The appropriate lethal concentrations at 24h for chloroform: methanol (1:1, v/v) extract was also studied on non target organisms such as Toxorhynchites larvae, Diplonychus annulatum and Chironomus circumdatus. In a 72 hour bioassay experiment, 0.5% crude extract showed the highest mortality and chloroform: methanol (1:1, v/v) solvent extract showed the highest mortality, the maximum (p larvicide agent. There is no changes in the activity non-target organism so, it is safe to use.

  19. The mode of bioturbation triggers pesticide remobilization from aquatic sediments.

    Science.gov (United States)

    Bundschuh, Mirco; Schletz, Marco; Goedkoop, Willem

    2016-08-01

    After their release into the aquatic environment, contaminants may - depending on the physicochemical properties - adsorb to sediments. From there these contaminants can either be buried or remobilised by abiotic factors (e.g., resuspension) as well as by the bioturbating activity of sediment dwelling invertebrates. Little is, however, know about the effects of bioturbation on the fate of pesticides. Therefore, the present study quantified the impact of the bioturbation mode of benthic invertebrate species (bio-diffusor vs. bio-irrigation), the invertebrate density (i.e. 0-8 individuals per replicate), and the substance-inherent properties (i.e. hydrophobicity, water solubility) on the remobilization of sediment-associated pesticides in a laboratory-based set-up over 13 days. We found that both the bioturbation mode (i.e., species identity) and species density, as well as pesticide properties (i.e., hydrophobicity) affected the direction and magnitude of remobilisation of sediment-bound pesticides. The oligochaeta Lumbriculus variegatus showed a density-dependent effect on the remobilization of lindane to the water phase, whereas those with the amphipod Monoporeia affinis and larvae of the midge Chironomus riparius did not. Although these findings show that sediments not per definition are a sink for pesticides, the rates of pesticide remobilization are limited. This observation, thus, suggests that the risk for aquatic communities posed by the remobilization of pesticides from the sediment due to bioturbation is low. PMID:27107774

  20. Sediment-associated pesticides in an urban stream in Guangzhou, China: implication of a shift in pesticide use patterns.

    Science.gov (United States)

    Li, Huizhen; Sun, Baoquan; Lydy, Michael J; You, Jing

    2013-04-01

    Pesticide use patterns in China have changed in recent years; however, the study of the environmental fate of current-use pesticides (CUPs) and their ecotoxicological significance in aquatic ecosystems is limited. In the present study, sediments were collected from an urban stream in the Chinese city of Guangzhou. Sediment-associated legacy organochlorine pesticides and CUPs-including organophosphates, pyrethroids, fipronil, and abamectin-were analyzed. Additionally, the relative toxicity of the sediments was evaluated with 10-d bioassays using Chironomus dilutus. Fifteen of 16 sediments collected from the stream were acutely toxic to C. dilutus, with 81% of the samples causing 100% mortality. Abamectin, fipronil, and pyrethroids (mainly cypermethrin) were identified as the principal contributors to the noted toxicity in the midges, with median predicted toxic units of 1.63, 1.63, and 1.03, respectively. Sediments taken from downstream sites, where residential and industrial regions were located, had elevated CUP concentrations and sediment toxicity compared with upstream sites. The present study is the first of its kind to link sediment CUPs, fipronil, and abamectin concentrations with toxicity in urban streams in China with a focus on shifting pesticide usage patterns. PMID:23377859

  1. How are macroinvertebrates of slow flowing lotic systems directly affected by suspended and deposited sediments?

    Energy Technology Data Exchange (ETDEWEB)

    Kefford, Ben J., E-mail: ben.kefford@rmit.edu.a [Biotechnology and Environmental Biology, School of Applied Sciences, RMIT University, PO Box 71, Bundoora, Victoria 3083 (Australia); Zalizniak, Liliana [Biotechnology and Environmental Biology, School of Applied Sciences, RMIT University, PO Box 71, Bundoora, Victoria 3083 (Australia); Dunlop, Jason E. [Department of Environment and Resource Management (DERM), 120 Meiers Rd, Indooroopilly, Queensland 4068 (Australia); Smart Water Research Facility, Griffith University, Queensland (Australia); Nugegoda, Dayanthi [Biotechnology and Environmental Biology, School of Applied Sciences, RMIT University, PO Box 71, Bundoora, Victoria 3083 (Australia); Choy, Satish C. [Department of Environment and Resource Management (DERM), 120 Meiers Rd, Indooroopilly, Queensland 4068 (Australia)

    2010-02-15

    The effects of suspended and deposited sediments on the macroinvertebrates are well documented in upland streams but not in slower flowing lowland rivers. Using species found in lowland lotic environments, we experimentally evaluate mechanisms for sediments to affect macroinvertebrates, and in one experiment whether salinity alters the effect of suspended sediments. Suspended kaolin clay reduced feeding of Ischnura heterosticta (Odonata: Coenagrionidae) at high turbidity (1000-1500 NTU) but had no effects on feeding of Hemianax papuensis (Odonata: Aeshnidae) and Micronecta australiensis (Hemiptera: Corixidae). In freshwater (0.1 mS/cm), survival of Ischnura aurora was poor in clear water, but improved with suspended kaolin. Growth and feeding of I. aurora were unaffected by suspended sediments and salinity. Burial (1-5 mm) of eggs with kaolin or sand reduced hatching in Physa acuta (Gastropoda: Physidae), Gyraulus tasmanica (Gastropoda: Planorbidae) and Chironomus cloacalis (Diptera: Chironomidae). Settling sediments may pose greater risk to lowland lotic invertebrates than suspended sediments. - Sediment deposition may be more directly detrimental to macroinvertebrates of lowland rivers than suspended sediments.

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

    Science.gov (United States)

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

    2013-01-01

    Few currently used agricultural pesticides are routinely monitored for in the environment. Even if concentrations are known, sediment LC(50) values are often lacking for common sediment toxicity testing species. To help fill this data gap, sediments in California's Central Valley were tested for nine hydrophobic pesticides seldom analyzed: abamectin, diazinon, dicofol, fenpropathrin, indoxacarb, methyl parathion, oxyfluorfen, propargite, and pyraclostrobin. Most were detected, but rarely at concentrations acutely toxic to Hyalella azteca or Chironomus dilutus. Only abamectin, fenpropathrin, and methyl parathion were found at concentrations of potential concern, and only in one or two samples. One-quarter of over 100 samples from agriculture-affected waterways exhibited toxicity, and in three-fourths of the toxic samples, pyrethroids exceeded concentrations expected to cause toxicity. The pyrethroid Bi-fen-thrin in particular, as well as lambda-cyhalothrin, cypermethrin, esfenvalerate, permethrin, and the organophosphate chlorpyrifos, were primarily responsible for the observed toxicity, rather than the more novel analytes, despite the fact that much of the sampling targeted areas of greatest use of the novel pesticides. PMID:22832339

  3. EVALUACIÓN PRELIMINAR DE LAS COMUNIDADES DE MACROINVERTEBRADOS BENTÓNICOS DE LA LAGUNA DE QUISTOCOCHA, IQUITOS, PERÚ

    Directory of Open Access Journals (Sweden)

    Jemima Alván Alvarado

    2012-12-01

    Full Text Available El objetivo del presente trabajo fue realizar una evaluación preliminar de la riqueza y abundancia de las comunidades de macroinvertebrados bentónicos colectados en dos estratos (orilla y 1 metro de profundidad de la Laguna de Quistococha (Loreto, Perú. Las muestras de orilla fueron colectadas utilizándose una red de colecta de bentos (en forma de D con malla de 1 mm2, mientras que las de 1 m de profundidad fueron colectadas con una draga tipo Eckman, colectándose en total 30 muestras (15 de orilla y 15 de 1 m de profundidad. En la orilla se registró la mayor riqueza (11 especies y abundancia (109 individuos de macroinvertebrados bentónicos, en comparación con la de 1 m de profundidad, donde solo se registraron 5 especies y 51 individuos, registrándose diferencias significativas según la prueba de Mann-Whitney (P<0,05. Para todas las zonas de colecta, la especie Chironomus sp. fue la más abundante tanto en orilla (79 individuos, 72,48%, como a 1 m de profundidad (43 individuos, 84,31%.

  4. Silver nanoparticle accumulation by aquatic organisms – neutron activation as a tool for the environmental fate of nanoparticles tracing

    Directory of Open Access Journals (Sweden)

    Asztemborska Monika

    2014-12-01

    Full Text Available Water environments are noted as being some of the most exposed to the influence of toxic nanoparticles (NPs. Therefore, there is a growing need for the investigation of the accumulation and toxicity of NPs to aquatic organisms. In our studies neutron activation followed by gamma spectrometry and liquid scintillation counting were used for studying the accumulation of silver nanoparticles (AgNPs by freshwater larvae of Chironomus and fish Danio rerio. The influence of exposition time, concentration and the source of nanoparticles on the efficiency of AgNP accumulation were studied. It was found that AgNPs are efficiently accumulated by Chironomid larvae for the first 30 hours of exposition; then, the amount of silver nanoparticles decreases. The silver content in larvae increases together with the NP concentration in water. Larvae which have accumulated AgNPs can be a source of nanoparticles for fish and certainly higher levels of Ag in the trophic chain. In comparison with water contamination, silver nanoparticles are more efficiently accumulated if fish are fed with AgNP-contaminated food. Finally, it was concluded that the applied study strategy, including neutron activation of nanoparticles, is very useful technique for tracing the uptake and accumulation of NPs in organisms

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

    International Nuclear Information System (INIS)

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

  6. Laboratory and field studies on the effect of molinate, clomazone, and thiobencarb on nontarget aquatic invertebrates.

    Science.gov (United States)

    Burdett, A S; Stevens, M M; Macmillan, D L

    2001-10-01

    The midge Chironomus tepperi was used in laboratory experiments to assess the relative toxicity of formulated molinate, clomazone, and thiobencarb, three herbicides used in Australian rice crops. Static bioassays were initiated with first-instar larvae at herbicide concentrations between 0.0625 and 2 times the anticipated field concentrations (AFCs) expected from the registered application rates. Adult emergence success, development time, and wing length were used as indices of the effect of each herbicide. Clomazone had no effect on any parameters at concentrations up to 0.288 mg/L (p > 0.05). Molinate significantly increased development time at concentrations equivalent to the AFC (3.6 mg/L) and above (p < 0.05). Thiobencarb reduced emergence success of adult C. tepperi at 0.0625 times the AFC (0.1875 mg/L) as well as decreasing male adult size and increasing development time for males and females at 0.125 times the AFC (p < 0.05). Nontarget effects of the herbicides on aquatic invertebrate communities were assessed in shallow experimental ponds using commercial application rates. One week after treatment, only thiobencarb had a significant effect, suppressing populations of chironomids, calanoids, and cyclopoids (p < 0.05). Four weeks later, all populations had recovered, equaling or exceeding control densities.

  7. Whole effluent toxicity assessment at a wastewater treatment plant upgraded with a full-scale post-ozonation using aquatic key species.

    Science.gov (United States)

    Magdeburg, Axel; Stalter, Daniel; Oehlmann, Jörg

    2012-08-01

    Ozonation as final wastewater (WW) polishing step, following conventional activated sludge treatment is increasingly implemented in sewage treatment for contaminant degradation to prevent surface water pollution. While the oxidative degradation of chemicals has been extensively investigated, the in vivo toxicological characteristics of ozonated whole effluents are rarely a matter of research. In the present study, whole effluents were toxicologically evaluated with an in vivo test battery before and after full-scale ozonation and subsequent sand filtration on site at a treatment plant. One aquatic plant (duckweed, Lemna minor) and five invertebrate species of different systematic groups (Lumbriculus variegatus, Chironomus riparius, Potamopyrgus antipodarum, Daphnia magna) were exposed to the effluents in a flow-through-designed test system with a test duration of 7-28 d. None of the considered toxicity endpoints correlated with the pollutant elimination. A tendency towards an increased toxicity after ozonation was apparent in three of the test systems showing [statistically] significant adverse effects in the L. variegatus toxicity test (decrease in reproduction and biomass). After sand filtration, adverse effects were reduced to a similar level like after conventional treatment. Solely the Daphnia reproduction test revealed beneficial effects after ozonation in combination with sand filtration. Results of the test battery indicate the formation of adverse oxidation products during WW ozonation. L. variegatus appeared to be the most sensitive of the five test species. Sand filtration effectively removes or detoxifies toxic oxidation products, as toxic effects were subsequently reduced to the level after conventional treatment. PMID:22560180

  8. Toxicity on aquatic organisms exposed to secondary effluent disinfected with chlorine, peracetic acid, ozone and UV radiation.

    Science.gov (United States)

    da Costa, Juliana Berninger; Rodgher, Suzelei; Daniel, Luiz Antonio; Espíndola, Evaldo Luiz Gaeta

    2014-11-01

    The toxic potential of four disinfectant agents (chlorine, ozone, peracetic acid and UV radiation), used in the disinfection of urban wastewater, was evaluated with respect to four aquatic organisms. Disinfection assays were carried out with wastewater from the city of Araraquara (São Paulo State, Brazil), and subsequently, toxicity bioassays were applied in order to verify possible adverse effects to the cladocerans (Ceriodaphnia silvestrii and Daphnia similis), midge larvae Chironomus xanthus and fish (Danio rerio). Under the experimental conditions tested, all the disinfectants were capable of producing harmful effects on the test organisms, except for C. xanthus. The toxicity of the effluent to C. silvestrii was observed to increase significantly as a result of disinfection using 2.5 mg L(-1) chlorine and 29.9 mg L(-1) ozone. Ozonation and chlorination significantly affected the survival of D. similis and D. rerio, causing mortality of 60 to 100 % in comparison to the non-disinfected effluent. In experiments with effluent treated with peracetic acid (PAA) and UV radiation, a statistically significant decrease in survival was only detected for D. rerio. This investigation suggested that the study of the ideal concentrations of disinfectants is a research need for ecologically safe options for the treatment of wastewater. PMID:25213288

  9. Characterizing the effects of bisphenol A on sediment-dwelling benthic organisms.

    Science.gov (United States)

    Staples, Charles; Mihaich, Ellen; Ortego, Lisa; Caspers, Norbert; Klečka, Gary; Woelz, Jan; Hentges, Steven

    2016-03-01

    Bisphenol A (BPA) is a high production volume chemical intermediate used primarily in the production of polycarbonate plastics and epoxy resins. It primarily enters surface water and sediment via effluent discharges during its manufacture and use. The physical properties of BPA suggest that sediment is a potential sink and may result in exposure to benthic organisms. Currently there are no studies measuring the chronic toxicity of BPA to benthic organisms via direct sediment exposure. The present study examined the chronic toxicity of BPA to 3 commonly used test organisms that are generally representative of invertebrates occupying the base of the benthic food web and for which standardized testing protocols are available: the oligochaete Lumbriculus variegatus (mean numbers and biomass), the midge Chironomus riparius (emergence and development rate), and the estuarine amphipod Leptocheirus plumulosus (survival, growth, and reproduction). No-observed-effect concentrations (NOECs) for the 3 species ranged from 12 mg/kg to 54 mg/kg dry weight. All NOEC values were higher than all measured concentrations of BPA in freshwater and marine sediments reported in reliable, fully reported studies from North America and Europe from the 1990s to the present. For the first time, there are studies with BPA measuring the chronic toxicity to 3 taxa of sediment dwelling invertebrates, which are suitable to support region-specific risk assessments. PMID:26297924

  10. The interaction of actinide and lanthanide ions with hemoglobin and its relevance to human and environmental toxicology.

    Science.gov (United States)

    Kumar, Amit; Ali, Manjoor; Ningthoujam, Raghumani S; Gaikwad, Pallavi; Kumar, Mukesh; Nath, Bimalendu B; Pandey, Badri N

    2016-04-15

    Due to increasing use of lanthanides/actinides in nuclear and civil applications, understanding the impact of these metal ions on human health and environment is a growing concern. Hemoglobin (Hb), which occurs in all the kingdom of living organism, is the most abundant protein in human blood. In present study, effect of lanthanides and actinides [thorium: Th(IV), uranium: U(VI), lanthanum: La(III), cerium: Ce(III) and (IV)] on the structure and function of Hb has been investigated. Results showed that these metal ions, except Ce(IV) interacted with carbonyl and amide groups of Hb, which resulted in the loss of its alpha-helix conformation. However, beyond 75μM, these ions affected heme moiety. Metal-heme interaction was found to affect oxygen-binding of Hb, which seems to be governed by their closeness with the charge-to-ionic-radius ratio of iron(III). Consistently, Ce(IV) being closest to iron(III), exhibited a greater effect on heme. Binding constant and binding stoichiometry of Th(IV) were higher than that of U(VI). Experiments using aquatic midge Chironomus (possessing human homologous Hb) and human blood, further validated metal-Hb interaction and associated toxicity. Thus, present study provides a biochemical basis to understand the actinide/lanthanide-induced interference in heme, which may have significant implications for the medical and environmental management of lanthanides/actinides toxicity. PMID:26799219

  11. Fluorotelomer acids are more toxic than perfluorinated acids.

    Science.gov (United States)

    Phillips, Michelle M MacDonald; Dinglasan-Panlilio, Mary Joyce A; Mabury, Scott A; Solomon, Keith R; Sibley, Paul K

    2007-10-15

    Saturated and unsaturated fluorotelomer carboxylic acids have been identified as intermediates in the degradation of fluorotelomer alcohols to perfluorinated carboxylic acids (PFCAs). Although surface waters are the likely environmental sink for telomer acids, no fate or toxicity data exist for this matrix. We assessed the acute toxicity of the 4:2, 6:2, 8:2, and 10:2 saturated (FTCA) and unsaturated (FTUCA) fluorotelomer carboxylic acids to Daphnia magna, Chironomus tentans, and Lemna gibba. In general, toxicity increased with increasing fluorocarbon (FC) chain length, particularly for telomer acids of > or =8 FCs. In addition, the FTCAs were generally more toxic than the corresponding FTUCAs. Acute EC50s ranged from 0.025 mg/L (0.04 micromol/L) for D. magna (10:2 FTCA, immobility) to 63 mg/L (167 micromol/L) for C. tentans (6:2 FTCA, growth). While chain-length trends observed in the current study agree with those previously reported for PFCAs, the toxicity thresholds generated here are up to 10,000 times smaller. Our data provide the first evidence that PFCA precursors are more toxic than the PFCAs themselves. PMID:17993163

  12. Environmental factors affecting the distribution of Chironomid larvae of the Seybouse wadi, North-Eastern Algeria

    Directory of Open Access Journals (Sweden)

    Nadjla Chaib

    2013-03-01

    Full Text Available A survey of the Seybouse wadi (North-Eastern Algeria between 2008 and 2011 was conducted in 26 sampling sites located on the main river and its tributaries using chironomids. From 3264 collected larvae, forty-five chironomid species were identified, and were correlated to 13 environmental variables to predict determinant factors affecting their distribution. Indicator value (IndVal analysis was first performed to determine indicator chironomid species according to several factors (sites, seasons, source distance, granulometry, conductivity, water temperature, dissolved oxygen, water velocity, pollution and the abundance of filamentous algae. Co-inertia analysis (CoIA supported the IndVal results, emphasising an upstream/downstream gradient in the first axis, while a granulometry gradient was emphasised by the second axis. A pollution gradient was also highlighted in the plane of the first two axes, separating tolerant Chironomus sp. 1, Cricotopus bicinctus and Cricotopus (Isocladius sylvestris from intolerant species as Phaenopsectra flavipes, Rheotanytarsus sp.1 and Cladotanytarsus sp. 1.

  13. Evaluation of target specific larvicidal activity of the leaf extract of Typhonium trilobatum against Culex quinquefasciatus Say

    Institute of Scientific and Technical Information of China (English)

    Koyel Mallick Haldar; Papiya Ghosh; Goutam Chandra

    2011-01-01

    Objective: To investigate the target specific larvicidal potential of an edible herb Typhonium trilobatum (T. trilobatum) (L.) Schott against mosquito Culex quinquefasciatus (Cx. quinquefasciatus) Say. Methods: Different concentrations of crude and methanol extract of T. trilobatum mature leaves were treated against Cx. quinquefasciatus larvae. LC50 concentration of crude extract on mosquito 3rd instar larvae was tested on Chironomus circumdatus and Diplonychus annulatum larvae. Preliminary phytochemical analysis was performed in search of plant’s secondary metabolites. Results:100%mortality of 1st instar mosquito larvae was recorded at 0.4%concentration after 72 h of exposure of crude extract. At 72 h 0.5%concentration produced 100%, 89.99%and 79.99%mortality of 2nd, 3rd and 4th instar larvae respectively. 50 ppm methanol extract showed 73.67%mortality of 3rd instar mosquito larvae at 72 h. 400 ppm concentration was responsible for 100%mortality in 24 h. Application of LC50 concentration (of 3rd instar mosquito larva) against non target organisms like C. circumdatus and D. annulatum larvae produced no significant mortality among them. Secondary metabolites like terpenoids and free glycoside bound anthraquinones were found. Conclusions:This experimental study was a pioneer attempt to establish T. trilobatum as a valuable resource of effective target specific mosquito larvicide.

  14. Experimental study and modelization of radium transfer in a simplified aquatic ecosystem

    International Nuclear Information System (INIS)

    Radium transfer has been studied in an experimental aquatic ecosystem composed by four trophic levels. Water and sediment are the two abiotic units from which the other compartments could be contamined. Scenedesmus obliquus represents the primary producer. Daphnia magna, Gammarus pulex and Chironomus sp., the first order consumers; Cyprinius carpio, the second order consumer and Salmo gairdneri, the third order one. Each transfer is described by a mathematical equation, based on a theoretical analysis, which represents concentration evolution of each compartment as a function of time. From the experimental data, we suggest a mathematical model in order to simulate radium contamination of the ecosystem. This model takes into account the following parameters: the contamination mode (chronic or acute pollution), the type of ecosystem concerned by the contamination (pond or river), and the season during which the pollution occurred. Results obtained with the model agree with most of field data on contamination level of fish living in the mining complex environment; particularly, they put the emphasize on the trophic way for the fish radiocontamination

  15. Effects of organic pollution and physical stress on benthic macroinvertebrate communities from two intermittently closed and open coastal lagoons (ICOLLs)

    Science.gov (United States)

    Coelho, Susana; Pérez-Ruzafa, Angel; Gamito, Sofia

    2015-12-01

    Benthic macroinvertebrate communities and environmental conditions were studied in two intermittently closed and open coastal lakes and lagoons (ICOLLs), located in southern Algarve (Foz do Almargem e Salgados), with the purpose of evaluating the effects of organic pollution, originated mainly from wastewater discharges, and the physical stress caused by the irregular opening of the lagoons. Most of the year, lagoons were isolated from the sea, receiving the freshwater inputs from small rivers and in Salgados, also from the effluents of a wastewater plant. According to environmental and biotic conditions, Foz do Almargem presented a greater marine influence and a lower trophic state (mesotrophic) than Salgados (hypereutrophic). Benthic macroinvertebrate communities in the lagoons were distinct, just as their relations with environmental parameters. Mollusca were the most abundant macroinvertebrates in Foz do Almargem, while Insecta, Oligochaeta and Crustacea were more relevant in Salgados. Corophium multisetosum occurred exclusively in Salgados stations and, just as Chironomus sp., other Insecta and Oligochaeta, densities were positively related to total phosphorus, clay content and chlorophyll a concentration in the sediment, chlorophyll a concentration in water and with total dissolved inorganic nitrogen. Abra segmentum, Cerastoderma glaucum, Peringia ulvae and Ecrobia ventrosa occurred only in Foz do Almargem, with lower values of the above mentioned parameters. Both lagoons were dominated by deposit feeders and taxa tolerant to environmental stress, although in Salgados there was a greater occurrence of opportunistic taxa associated to pronounced unbalanced situations, due to excess organic matter enrichment.

  16. Acute toxicity of metals and reference toxicants to a freshwater ostracod, Cypris subglobosa Sowerby, 1840 and correlation to EC{sub 50} values of other test models

    Energy Technology Data Exchange (ETDEWEB)

    Khangarot, B.S., E-mail: bkhangarot@hotmail.com [Ecotoxicology Division, Indian Institute of Toxicology Research (Formerly: Industrial Toxicology Research Centre), Post Box No. 80, Mahatma Gandhi Marg, Lucknow 226001 (India); Das, Sangita [Ecotoxicology Division, Indian Institute of Toxicology Research (Formerly: Industrial Toxicology Research Centre), Post Box No. 80, Mahatma Gandhi Marg, Lucknow 226001 (India)

    2009-12-30

    The ostracod Cypris subglobosa Sowerby, 1840 static bioassay test on the basis of a 48 h of 50% of immobilization (EC{sub 50}) has been used to measure the toxicity of 36 metals and metalloids and 12 reference toxicants. Among the 36 metals and metalloids, osmium (Os) was found to be the most toxic in the test while boron (B), the least toxic. The EC{sub 50} values of this study revealed positive linear relationship with the established test models of cladoceran (Daphnia magna), sludge worm (Tubifex tubifex), chironomid larvae (Chironomus tentans), protozoan (Tetrahymena pyriformis), fathead minnow (Pimephales promelas), bluegill sunfish (Lepomis macrochirus), and aquatic macrophyte duckweed (Lemna minor). Correlation coefficients (r{sup 2}) for 17 physicochemical properties of metals or metal ions and EC{sub 50}s (as pM) were examined by linear regression analysis. The electronegativity, ionization potential, melting point, solubility product of metal sulfides (pK{sub sp}), softness parameter and some other physicochemical characteristics were significantly correlated with EC{sub 50}s of metals to C. subglobosa. The reproducibility of toxicity test was determined using 12 reference toxicants. The coefficient of variability of the EC{sub 50}s ranged from 6.95% to 55.37% and variability was comparable to that noticed for D. magna and other aquatic test models. The study demonstrated the need to include crustacean ostracods in a battery of biotests to detect the presence of hazardous chemicals in soils, sewage sludges, sediments and aquatic systems.

  17. Characterization of the potential impact of metal contaminated sediments on aquatic plants and insects at the Savannah River Site

    International Nuclear Information System (INIS)

    Tim's Branch is an ephemeral second order tributary of Upper Three Runs Creek at the Savannah River Site (SRS). At present, Tim's Branch is the receiving stream for eight NPDES outfalls. Historic contamination of Tim's Branch through untreated discharges has resulted in significant levels of natural uranium, nickel, aluminum, mercury, copper, lead, chromium, and zinc in the stream sediments and flood plain. Indigenous plant and chironomid species in the area were identified. Sediment, benthic invertebrate and aquatic plant samples were harvested from several sites to determine metal concentrations. Physical and chemical parameters of sediment including acid volatile sulfides, pH, oxidation/reduction potential, organic carbon and particle size distribution were assessed to determine their influence on metal bioavailability. Laboratory tests indicated that significant levels of heavy metals are translocated from sediment to Hydrilla verticillata with a concurrent elevation of plant peroxidase activity. Laboratory sediment toxicity bioassays were also performed with laboratory-reared Chironomus tentans. In situ sediment toxicity bioassays were performed with indigenous chironomids and plants to validate laboratory results

  18. Rapid Recovery of Chironomidae (Diptera) in Little Mill Creek (Kansas, U.S.A.) After the Decommissioning of a Waste Water Treatment Plant

    Science.gov (United States)

    Bouchard, R. W.; Ferrington, L. C.

    2005-05-01

    In June 1995 the Lenexa Waste Water Treatment Plant was decommissioned, providing an opportunity to study recovery of Chironomidae community structure in Little Mill Creek. Using pupal exuviae, weekly changes in the species richness and composition of Chironomidae emerging upstream and downstream of the effluent outfall was evaluated from two weeks before decommissioning to eight weeks post-decommissioning. Chironomidae emergence was clearly different between upstream and downstream sites both before and shortly after effluent input ceased. Before decommissioning, sites immediately downstream of the effluent had low species richness and were dominated by Chironomus riparius (Meigen) and other tolerant taxa, with some recovery at sites farther downstream. Two weeks after decommissioning, only sites immediately downstream of the former effluent were clearly impacted, but effects were reduced compared to pre-recovery collections. At five weeks post-decommissioning, species richness was only slightly lower at the sites immediately downstream of the former effluent and the composition of common species (i.e., >5% of relative abundance) was similar between upstream and downstream sites. Rapid recovery of chironomid emergence below the sewage effluent likely resulted from both colonization of drifting larvae from upstream sources and adult dispersal and oviposition, indicating rapid responses in emergence as water quality conditions improved.

  19. Evaluation of the resident-species procedure for developing site-specific water quality criteria for copper in Blaine Creek, Kentucky

    International Nuclear Information System (INIS)

    Acute toxicity tests were performed on each of nine different organisms in Blaine Creek (Lawrence County, KY) water to determine 48-h LC50 values for copper (Cu). Blaine Creek is the receiving stream for Kentucky Power Company's Big Sandy Plant fly-ash pond discharge. Selection of the nine tested species and integration of the results were based on the US Environmental Protection Agency's (EPA's) resident-species procedure. The following LC50 (μg Cu/L) values were obtained: Daphnia pulex 37; Physella sp. 109; Isonychia bicolor 223; Pimephales promelas 284; Stenonema sp. 453; Eurycea bislineata 1,120; Chironomus riparius 1,170; Orconectes sp. 2,370; Lepomis macrochirus 4,300. A final acute value (FAV) of 10.1 μg Cu/L was derived using the Blaine Creek database, which is lower than the EPA's national FAV. The differences in FAVs were due to the effect of database size, not differences in the relative sensitivity of test organisms. The findings provide caution for dischargers who may choose to use the resident-species procedure for future site-specific water-quality-criteria demonstrations. The resident-species procedure, because of the inherent conservative bias of the calculation process, tends to produce more stringent criteria when used on a site-specific basis. A modified recalculation procedure, in conduction with site-specific metal bioavailability data, was judged to be the most appropriate method for deriving site-specific Cu criteria for Blaine Creek

  20. Assessing condition of macroinvertebrate communities and sediment toxicity in the St. Lawrence River at Massena Area-of-Concern

    Science.gov (United States)

    Duffy, Brian T.; Baldigo, Barry P.; Smith, Alexander J; George, Scott D.; David, Anthony M.

    2016-01-01

    In 1972, the USA and Canada agreed to restore the chemical, physical, and biological integrity of the Great Lakes ecosystem under the first Great Lakes Water Quality Agreement. In subsequent amendments, part of the St. Lawrence River at Massena, New York and segments of three tributaries, were designated as an Area of Concern (AOC) due to the effects of polychlorinated biphenyls (PCBs), lead and copper contamination, and habitat degradation and resulting impairment to several beneficial uses. Because sediments have been largely remediated, the present study was initiated to evaluate the current status of the benthic macroinvertebrate (benthos) beneficial use impairment (BUI). Benthic macroinvertebrate communities and sediment toxicity tests using Chironomus dilutus were used to test the hypotheses that community condition and sediment toxicity at AOC sites were not significantly different from those of adjacent reference sites. Grain size was found to be the main driver of community composition and macroinvertebrate assemblages, and bioassessment metrics did not differ significantly between AOC and reference sites of the same sediment class. Median growth of C. dilutus and its survival in three of the four river systems did not differ significantly in sediments from AOC and reference sites. Comparable macroinvertebrate assemblages and general lack of toxicity across most AOC and reference sites suggest that the quality of sediments should not significantly impair benthic macroinvertebrate communities in most sites in the St. Lawrence River AOC.

  1. Systematic studies of Oryzomyine rodents (Muridae, Sigmodontinae): diagnoses and distributions of species formerly assigned to Oryzomys 'capito'

    Science.gov (United States)

    Musser, G.G.; Carleton, M.D.; Brothers, E.M.; Gardner, A.L.

    1998-01-01

    We describe the morphological species-boundaries and geographic distributions of ten Neotropical Oryzomys based on analyses of museum specimens (skins and skulls, examples preserved in fluid, chromosomal spreads, and information about collection sites from skin tags, field catalogs, and other sources). These species have been regarded as members of an Oryzomys capito complex and for a long time were consolidated into a single entity identified as O. capito. Our study documents the following: 1. Defining the limits of species within the O. capito complex first requires a comprehensive review and rigorous definition of O. capito itself. We consider Fischer's (1814) Mus megacephalus to be valid and available, designate a neotype to bear the name, and reinstate it as a senior synonym of capito Olfers (1818). We then provide a working definition of O. megacephalus and its close relative, O. laticeps, derived from analyses of morphometric variation, estimates of geographic distributions, and evaluations of synonyms. In our view, O. megacephalus occurs in Amazonia but also extends into eastern Paraguay; its synonyms are capito Olfers (1818), cephalotes Desmarest (1819), velutinus Allen and Chapman (1893), goeldi Thomas (1897), modestus Allen (1899), and perenensis Allen (1901). Oryzomys laticeps Lund (1840) occurs in the Atlantic Forest region of eastern Brazil. We designate a lectotype for laticeps and allocate the names saltator Winge (1887) and oniscus Thomas (1904) as synonyms. 2. We provide the first comprehensive taxonomic revision of Oryzomys yunganus Thomas (1902). Its range covers tropical evergreen rainforest formations in the Guiana region and the Amazon Basin where, as documented by voucher specimens, it has been collected at the same localities as O. megacephalus, O. nitidus, and O. tern of carotid arterial circulation, occlusal patterns of second upper and lower molars, cranial proportions, and chromosomal features. Appreciable intraspecific geographic

  2. COMPOSIÇÃO E DENSIDADE DO BANCO DE SEMENTES EM UMA FLORESTA DE VÁRZEA, ILHA DO COMBU, BELÉM-PA, BRASIL

    Directory of Open Access Journals (Sweden)

    Arthur Viana Lau

    2014-10-01

    Full Text Available Este estudo teve como objetivo caracterizar a composição e densidade do banco de sementes de um trecho de floresta de várzea localizada na Área de Proteção Ambiental (APA Ilha do Combu, no município de Belém, PA, Brasil. Foram alocadas sistematicamente 6 parcelas de 20 x 20m em três áreas da floresta distante 100m uma da outra perfazendo um total de 0,24ha. Em cada parcela foi utilizado um gabarito de madeira medindo 50 x 50 cm para a padronização e coleta de 20 amostras do banco de sementes do solo a 20 cm de profundidade desprezando-se a serapilheira. As 120 amostras foram depositadas em sacos plásticos de 30 litros e transportadas para o Horto Botânico localizado no campus de pesquisa do Museu Paraense Emílio Goeldi (MPEG. As amostras foram distribuídas em recipientes plásticos medindo 36 cm x 5 cm de profundidade em um viveiro suspenso com sombrite a 50%. O experimento foi conduzido de maio a agosto de 2013 com a quantificação das plântulas a partir de 10 cm de altura e identificadas em nível de família, gênero, espécie e calculada a densidade média de plântulas. Para comparar a diversidade de espécies foram utilizados o índice de diversidade de Shannon-Wiener (H' e o índice de similaridade de Sorensen (S. Foram registradas 26 famílias, 38 gêneros e 41 espécies. As famílias mais representativas foram Poaceae, Asteraceae e Cyperaceae com quatro espécies cada e as espécies com maiores densidades foram Polybotrya caudata Kunze, Cecropia palmata Willd., Cyperus difformis L., Alternanthera tenella, Clidemia hirta (L. D. Don, Commelina erecta L. e Phyllanthus niruri L. A forma de crescimento herbácea foi dominante em todas as áreas. Foi registrado o índice de H'=0,86 nat-3ind para a área 1; H'=1,91 nats-3ind para a área 2 e H'=1,35 nats-3ind para a área 3 e a similaridade de S'=0,50 para a área 1; S'=0,48 para a área 2 e S'=0,50 para a área 3. A composição florística do banco de sementes foi

  3. Aspectos da reprodução e alimentação de Neoplecostomus microps (Loricariidae, Neoplecostominae na microbacia do Ribeirão Grande, serra da Mantiqueira oriental (Estado de São Paulo = Reproduction and feeding aspects of Neoplecostomus microps (Loricariidae, Neoplecostominae in the Ribeirão Grande system, eastern Serra da Mantiqueira (São Paulo State

    Directory of Open Access Journals (Sweden)

    Francisco Manoel de Souza Braga

    2008-10-01

    Full Text Available A microbacia do Ribeirão Grande situa-se nas vertentes da serra da Mantiqueira e está circundada pela floresta Atlântica. Foram amostrados oito locais na microbacia do Ribeirão Grande, no inverno (julho de 2001, primavera (outubro de 2001, verão (fevereiro de 2002 e outono (abril de 2002. As amostras foram coletadas com um aparelho elétrico de pesca. A maturação das gônadas, os graus de repleção do estômago e de gordura visceral foram distribuídasem um ciclo anual. Neoplecostomus microps tem período de desova que vai da primavera ao verão. O tamanho da primeira maturação gonadal para machos foi de 5,9 cm de comprimento total e de 6,9 cm para as fêmeas. O alto valor em outubro e fevereiro para a relação gonadossomática e para o fator de condição relativo coincidiram com o período de desova. Foram encontradas, na dieta de N. microps, larvas de Diptera (Simulium, Chironomus, ninfas de Plecoptera e larvas deColeoptera aquáticas (Psephenus. O aumento da alimentação, do verão ao outono, proporcionou acúmulo de gordura visceral. Durante as estações seguintes, o peixe pode utilizar as reservas de gordura para a manutenção e reprodução. O padrão reprodutivo e o de alimentação foram interpretados como sendo adaptações em relação às variações temporais e espaciais no ambiente e na disponibilidade de alimento.The Ribeirão Grande system is located in the slope of the Serra da Mantiqueira and is surrounded by Atlantic forest. Eight sites were surveyed in the Ribeirão Grande system, during the winter (July 2001, spring (October 2001, summer (February 2002 and fall (April 2002. Samples were made with an electrofishing device. Gonad maturation, levels of stomach fullness and fat content were analyzed and their distributions reported in an annual cycle. Neoplecostomus microps has a spawning in the spring through to summer. The size at sexual maturity is about 5.9 cm total length for males and 6.9 cm for females. The

  4. 西泉眼水库水源地10月大型底栖动物群落特征及其与环境因子的关系%Characteristics of Macrobenthos Communities in Xiquanyan Reservoir in Autumn and Their Relationships with Environmental Factors

    Institute of Scientific and Technical Information of China (English)

    李佳娟; 于洪贤; 刘曼红; 费滕

    2011-01-01

    2010年10月,通过对西泉眼水库大型底栖动物采样调查,结合Bray-Curtis相似性系数聚类、多维尺度、典范对应分析,以及物种优势度指数、Margalef种类丰富度指数、Shannon-Wiener多样性指教、Pielou均匀度指数和Goodnight- Whitley生物指数等方法,分析了该水库秋季大型底栖动物群落结构特征及其与环境因子的关系,为水质保护与治理提供生物学依据.调查共采集到大型底栖动物50种.其中:节肢动物41种,占82%;环节动物7种,占14%;软体动物2种,占4%.水库优势种为纹石蛾(Hydropsyche sp.)1种、划蝽(Arctocorisa sp.)1种、中华摇蚊(Chironomus sinicus)度霍甫水丝蚓(Limnodrilus hoffmeisteri).13个采样点划分为4个区域:区域Ⅰ的生物多样性较差;区域Ⅱ的生物多样性最好;区域Ⅲ的生物多样性处于两者之间;区域Ⅳ没有采集到大型底栖动物.西泉眼水库大型底栖动物的空间分布主要受高锰酸盐指数、总磷、氨氮及亚硝酸盐氮等环境因子的影响.%An investigation was made in October 2010 to study the community structures of macrpbenthos in Xiquanyan reservoir and their relationships with environmental factors by the method of field investigation in combining with Bray-Curtis analysis, multi-dimensional scaling analysis and canonical correspondence analysis, and using the indices of McNaughton index, Margalef, Shannon-Wiener, Pielou and Goodnight-Whitley, aiming to provide a biological basis for water quality protection and management. A total of 50 macrobenthos species were collected, among which 41 species (82% of total) were arthropods, 7 species (14% ) were annelids, and 2 species (4%) were mollusks. The dominant species were Hydro-psyche nahaharai, Cenocorixa hungerford, Chironomus sinicus and Limnodrilus hoffmeisteri. The thirteen sites were classified into four groups. The biodiversity was poor in the first group; the second one had the highest biodiversity

  5. Larvas de Chironomidae arvas (Diptera da planície de inundação do alto rio Paraná: distribuição e composição em diferentes ambientes e períodos hidrológicos = Chironomidae larvae (Diptera from the upper Paraná river floodplain: distribution and composition in different environments and hydrological periods

    Directory of Open Access Journals (Sweden)

    Gisele Cristina Rosin

    2007-01-01

    Full Text Available O presente estudo teve por objetivos, identificar possíveis diferenças na estrutura da comunidade de larvas de Chironomidae em quatro ambientes da planície de inundação do alto rio Paraná com diferentes características e analisar a influência dos fatores abióticos e das variações do nível hidrométrico sobre a comunidade. As coletas foram realizadas em março e setembro de 2003. Em cada um dos 12 pontos coletados foram realizadas quatro amostragens: três para análise biológica e uma para análise sedimentológica. O material biológico foi lavado em conjunto de peneiras com malhas de abertura 2, 1 e 0,2 mm e fixado em álcool 70%. As larvas de Chironomidae foram identificadas até a categoria de gênero. Foram encontradas 1478larvas de Chironomidae pertencentes a 19 gêneros. Polypedilum, Tanytarsus e Chironomus foram registrados em todos os ambientes. As maiores densidades e diversidade de Chironomidae foram registradas nos períodos de águas baixas, especialmente em ambientes lênticos. Avariação da densidade, dominância e diversidade de Chironomidae entre as duas coletas foi influenciada, principalmente, pelo ciclo hidrológico e pelo oxigênio dissolvido, enquanto que a variação espacial esteve associada ao tipo de sedimento, porcentagem de matéria orgânica e a presença ou ausência de macrófitas aquáticas.The present study had the aim to identify possible differences in the community structure of Chironomidae larvae in four different environments of the upper Paraná river floodplain with different characteristics and to analyze the influence of abiotic factors and variations in the hydrometric level of the community. Samplings were carried out in March and September, 2003. Four samplings were taken from each of the 12 collecting points: three for biological analysis and one for sediment analysis. Biological contents were washed with the aid of a system with 2.0; 1.0 and 0.2 mm sieves. Chironomidae larvae were

  6. 食蚊鱼对水生昆虫的捕食选择性研究%Predacious Selection of Gambusia affinis on Aquatic Insects

    Institute of Scientific and Technical Information of China (English)

    刘丽娟; 童晓立

    2012-01-01

    To investigate the effects of mosquitofish, Gambusia affinis on aquatic insect biodiversity in South China, three common species of aquatic insects in mosquitofish habitat, I. E. , Cloeon bengalense, Chironomus kiiensis and Aedes albopictus, were selected under the lab condition to test the feeding preference of mosquitofish. The resulted showed that mosquitofish had no significant feeding selection on all preys in low density under the single-predator-and-multiple-preys experimental design. But mosquitofish preferred the larvae and pupa of A. Albopictus to other preys with the increase of prey density. When the prey ratio was 1' 1 under the single-predator-and-two-prey experimental design, mosquitofish frequently prefer larvae of A. Albopictus to the other prey. However, there was no significant influence to total prey consumption for mosquitofish when prey ratio was changed but total prey numbers unchanged. The results suggested that G. Affinis preferred to feed on the mobile prey close to water surface and showed no interest in the unmoving or dead prey, and mosquito larvae were the favorite prey of mosquitofish compared with mayflies and chironomids.%为了解食蚊鱼Gambusia affinis对华南地区水生昆虫多样性的影响,在实验室条件下,以食蚊鱼栖境中有代表性的3种水生昆虫为猎物,研究食蚊鱼的捕食选择性.结果表明,在单捕食者-多种猎物作用系统中,当猎物密度较低时,食蚊鱼对不同猎物的捕食选择性差异不显著.但随猎物密度的增加,食蚊鱼对白纹伊蚊Aedesalbopictus幼虫和蛹的捕食量明显增加,对摇蚊Chironomus kiiensis幼虫和蜉蝣Cloeon bengalense稚虫的捕食量下降.在单捕食者-2种猎物的作用系统中,在猎物比例相同的情况下,食蚊鱼更喜欢捕食白纹伊蚊幼虫;但是在猎物总数不变的情况下,改变猎物比例,对食蚊鱼总的捕食量影响不大.说明食蚊鱼喜欢捕食漂浮于水面上、会动的活体猎物,对

  7. Response of Sediment Micro Environment and Micro Interface to physical Disturbance Intensity Under the Disturbance of Choronomus plumosus%摇蚊幼虫扰动下沉积物微环境和微界面对物理扰动强度的响应

    Institute of Scientific and Technical Information of China (English)

    史晓丹; 李勇; 李大鹏; 王忍; 邓猛; 黄勇

    2015-01-01

    以太湖梅梁湾沉积物为研究对象,借助 Rhizon 间隙水采样技术、 Unisense 微电极技术,解析了物理扰动和摇蚊幼虫组合扰动下,沉积物微环境及微界面特征对物理扰动强度的响应规律.结果表明,高强度物理扰动下(240 r•min -1),溶解氧渗透深度(OPD)达到12.1 mm,远高于低强度(60 r•min -1)的3.8 mm.沉积物总氧气交换速率(TOE)、 TOE 与 DOE 差值、 ORP、溶解氧渗透深度(OPD)、 DO 空间分布的差异性等均显示了与物理扰动强度正相关趋势.沉积物中 pH 增加的区域和幅度及Fe2+减小的区域和幅度也显示了相同响应规律;在沉积物表层0~6 cm 范围内,相同深度沉积物的含水率、孔隙度、总微生物活性均随物理扰动强度增加呈递增趋势,并对物理扰动强度的响应程度随沉积物深度递增逐渐减弱.这暗示了物理扰动胁迫摇蚊幼虫构造更深和更多的廊道,进而从垂向的角度改造了沉积物微界面和微环境.%The response of sediment micro environment and micro interface to physical disturbance intensity under the physical and Chironomus plumosus disturbance was investigated by means of sediment Rhizon samplers and Unisense micro sensor system. The sediment and overlying water were taken from Meiliang bay of Taihu Lake. The results showed that the OPD reached up to 12. 1 mm under the high intensity (240 r•min - 1 ), while it was higher than 3. 8 mm under low intensity (60 r•min - 1 ). The TOE, the difference of TOE and DOE, OPD, ORP and the difference of DO spatial distribution were all positively correlated with the physical disturbance intensity. The increasing magnitude and range of pH as well as the decreasing magnitude and range of ferrous followed the same response tendency. Within the 0-6 cm sediment, the water content and porosity as well as the microbial activity at the same depth increased with the increase of physical disturbance intensity. In addition, the degree

  8. Estructura del macrobentos de la laguna de Paca, Junín

    Directory of Open Access Journals (Sweden)

    Pedro Huamán

    2013-06-01

    Full Text Available Se caracterizó la estructura comunitaria del macrobentos de la laguna de Paca ubicada a 3364 msnm, a 11º 45 S y 75º 30’ W en el departamento de Junín-Perú. También se analizaron los principales factores físicos y químicos del agua y sedimentos que condicionan dicha estructura. Los muestreos se realizaron en el año 2000 en 8 estaciones, distribuidas en la zona litoral (5 y pelágica (3. En cada estación se tomaron muestras de agua cercana al fondo y de sedimentos para analizar los parámetros físicos, químicos y biológicos de la comunidad del macrobentos. Los datos fueron sometidos a pruebas univariadas y multivariadas para determinar el grado de interacción de los diversos factores con las variables biológicas. La diversidad del macrobentos es baja y muestra valores de diversidad menores a 1,5 y el número de especies menores a 11 especies. La abundancia varía en valores que van desde los 16 hasta 176 individuos/0,04 m2 . Tubifex tubifex y Chironomus sp. fueron las especies más resistentes a los altos valores de materia orgánica (35,22 a 38,28% y bajos valores de oxígeno disuelto (1 a 2 mg/L, lo que constituye indicadores biológicos de eutroficación.

  9. Diverse circular replication-associated protein encoding viruses circulating in invertebrates within a lake ecosystem.

    Science.gov (United States)

    Dayaram, Anisha; Galatowitsch, Mark L; Argüello-Astorga, Gerardo R; van Bysterveldt, Katherine; Kraberger, Simona; Stainton, Daisy; Harding, Jon S; Roumagnac, Philippe; Martin, Darren P; Lefeuvre, Pierre; Varsani, Arvind

    2016-04-01

    Over the last five years next-generation sequencing has become a cost effective and efficient method for identifying known and unknown microorganisms. Access to this technique has dramatically changed the field of virology, enabling a wide range of environmental viral metagenome studies to be undertaken of organisms and environmental samples from polar to tropical regions. These studies have led to the discovery of hundreds of highly divergent single stranded DNA (ssDNA) virus-like sequences encoding replication-associated proteins. Yet, few studies have explored how viruses might be shared in an ecosystem through feeding relationships. Here we identify 169 circular molecules (160 CRESS DNA molecules, nine circular molecules) recovered from a New Zealand freshwater lake, that we have tentatively classified into 51 putatively novel species and five previously described species (DflaCV-3, -5, -6, -8, -10). The CRESS DNA viruses identified in this study were recovered from molluscs (Echyridella menzeisii, Musculium novaezelandiae, Potamopyrgus antipodarum and Physella acuta) and insect larvae (Procordulia grayi, Xanthocnemis zealandica, and Chironomus zealandicus) collected from Lake Sarah, as well as from the lake water and benthic sediments. Extensive diversity was observed across most CRESS DNA molecules recovered. The putative capsid protein of one viral species was found to be most similar to those of members of the Tombusviridae family, thus expanding the number of known RNA-DNA hybrid viruses in nature. We noted a strong association between the CRESS DNA viruses and circular molecules identified in the water and browser organisms (C. zealandicus, P. antipodarum and P. acuta), and between water sediments and undefended prey species (C. zealandicus). However, we were unable to find any significant correlation of viral assemblages to the potential feeding relationships of the host aquatic invertebrates. PMID:26873065

  10. Persistence of aquatic insects across managed landscapes: effects of landscape permeability on re-colonization and population recovery.

    Directory of Open Access Journals (Sweden)

    Nika Galic

    Full Text Available Human practices in managed landscapes may often adversely affect aquatic biota, such as aquatic insects. Dispersal is often the limiting factor for successful re-colonization and recovery of stressed habitats. Therefore, in this study, we evaluated the effects of landscape permeability, assuming a combination of riparian vegetation (edge permeability and other vegetation (landscape matrix permeability, and distance between waterbodies on the colonization and recovery potential of weakly flying insects. For this purpose, we developed two models, a movement and a population model of the non-biting midge, Chironomus riparius, an aquatic insect with weak flying abilities. With the movement model we predicted the outcome of dispersal in a landscape with several linear water bodies (ditches under different assumptions regarding landscape-dependent movement. Output from the movement model constituted the probabilities of encountering another ditch and of staying in the natal ditch or perishing in the landscape matrix, and was used in the second model. With this individual-based model of midge populations, we assessed the implications for population persistence and for recovery potential after an extreme stress event. We showed that a combination of landscape attributes from the movement model determines the fate of dispersing individuals and, once extrapolated to the population level, has a big impact on the persistence and recovery of populations. Population persistence benefited from low edge permeability as it reduced the dispersal mortality which was the main factor determining population persistence and viability. However, population recovery benefited from higher edge permeability, but this was conditional on the low effective distance that ensured fewer losses in the landscape matrix. We discuss these findings with respect to possible landscape management scenarios.

  11. Ecotoxicological assessment of the pharmaceutical compound Triclosan to freshwater invertebrates with emphasis to spiked sediment tests

    International Nuclear Information System (INIS)

    The increasing of Pharmaceutical and Personal Care Products (PPCPs) occurrence in the aquatic environment cause adverse effects on the human health and aquatic communities. The environmental risk of the PPCPs associated with the possibility of synergic effects between PCPPs and the increase of the use of synthetic organic compounds, unchained a great concern on the toxic potential to biota aquatic. Triclosan (5-chloro-2-(2,4-dichlorophenoxy)-phenol) is a pharmaceutical compound widely used due your antibacterial mechanism effect, found in at least 932 products such as shampoos, toilet soaps, deodorants, lotions, toothpaste, detergents, socks and underwear, among others. Currently, studies about the Triclosan toxicity in the water and, mainly in the sediment, are poorly. We have the knowledge that the photodegradation of this product results into dichlorodibenzo-p-dioxin, and now it has great discussion on environmental agencies, like EPA, about the release or restriction of this product. The aim of this work is to assess the effects of Triclosan on mortality of insect larvae Chironomus xanthus and mortality and reproduction inhibition of microcrustacea Ceriodaphnia dubia exposed to Triclosan spiked sediments based on standard methods EPA and OECD. The EC50;96H obtained on acute toxicity tests with C. xanthus was 45,26 mg.Kg-1. The chronic toxicity tests with C. dubia using spiked sediments were performed following the procedure in Burton and MacPherson (1995). A no-observed-effect concentrations and lowest-observed-effect concentration were 5,78 e 6,94 mg.Kg-1, respectively. (author)

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

    Science.gov (United States)

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

    2016-04-15

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

  13. Comparative responses of freshwater organisms to exposures of a commercial naphthenic acid.

    Science.gov (United States)

    Kinley, Ciera M; McQueen, Andrew D; Rodgers, John H

    2016-06-01

    Comparative toxicity studies using unconfounded exposures can prioritize the selection of sensitive sentinel test species and refine methods for evaluating ecological risks of complex mixtures like naphthenic acids (NAs), a group of organic acids associated with crude oils and energy-derived waters that have been a source of aquatic toxicity. The objectives of this study were to compare responses of freshwater aquatic organisms (vertebrate, invertebrates, and a macrophyte; in terms of acute toxicity) to Fluka commercial NAs and to compare measured toxicity data with peer-reviewed toxicity data for other commercial NA sources and energy-derived NA sources. Exposures were confirmed using high performance liquid chromatography. Responses (7-d LC50s/EC50) ranged from 1.9 mg L(-1) for Pimephales promelas to 56.2 mg L(-1) for Typha latifolia. Following P. promelas in order of decreasing sensitivity were Ceriodaphnia dubia (7-d LC50 = 2.8 mg L(-1)), Hyalella azteca (7-d LC50 = 4.1 mg L(-1)), Chironomus dilutus (7-d LC50 = 6.5 mg L(-1)), and T. latifolia (7-d EC50 = 56.2 mg L(-1)), indicating that in terms of sensitivities, fish > invertebrates > plant for Fluka NAs in this study. Factors that affect exposures and measurements of exposures differ among commercial and energy-derived NAs and constrain comparisons. Despite differences in exposures, fish and invertebrates were relatively sensitive to both commercial and energy-derived NA sources (based on laboratory measurements and peer-reviewed data) and could be appropriate sentinel species for risk evaluations. PMID:27016812

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

    Science.gov (United States)

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

    2016-07-01

    Understanding the role of species traits in chemical exposure is crucial for bioaccumulation and toxicity assessment of chemicals. We measured and modelled bioaccumulation of polychlorinated biphenyls (PCBs) in Chironomus riparius, Hyalella azteca, Lumbriculus variegatus and Sphaerium corneum. We used a battery test procedure with multiple enclosures in one aquarium, which maximized uniformity of exposure for the different species, such that the remaining variability was due mostly to species traits. The relative importance of uptake from either pore water or sediment ingestion was manipulated by using 28 d aged standard OECD sediment with low (1%) and medium (5%) OM content and 13 months aged sediment with medium OM (5%) content. Survival was ≥76% and wet weight increased for all species. Reproduction of H. azteca and weight gain of H. azteca and S. corneum were significantly higher in the medium OM aged sediments than in other sediments, perhaps due to a more developed microbial community (i.e., increase in food resources). Biota-sediment accumulation factors (BSAF) ranged from 3 to 114, depending on species and PCB congener, with C. riparius (3-10)

  15. Ecotoxicological assessment of the pharmaceutical compound Triclosan to freshwater invertebrates with emphasis to spiked sediment tests; Avaliacao ecotoxicologica do farmaco Triclosan para invertebrados de agua doce com enfase em ensaios com sedimento marcado ('spiked sediment')

    Energy Technology Data Exchange (ETDEWEB)

    Pusceddu, Fabio Hermes

    2009-07-01

    The increasing of Pharmaceutical and Personal Care Products (PPCPs) occurrence in the aquatic environment cause adverse effects on the human health and aquatic communities. The environmental risk of the PPCPs associated with the possibility of synergic effects between PCPPs and the increase of the use of synthetic organic compounds, unchained a great concern on the toxic potential to biota aquatic. Triclosan (5-chloro-2-(2,4-dichlorophenoxy)-phenol) is a pharmaceutical compound widely used due your antibacterial mechanism effect, found in at least 932 products such as shampoos, toilet soaps, deodorants, lotions, toothpaste, detergents, socks and underwear, among others. Currently, studies about the Triclosan toxicity in the water and, mainly in the sediment, are poorly. We have the knowledge that the photodegradation of this product results into dichlorodibenzo-p-dioxin, and now it has great discussion on environmental agencies, like EPA, about the release or restriction of this product. The aim of this work is to assess the effects of Triclosan on mortality of insect larvae Chironomus xanthus and mortality and reproduction inhibition of microcrustacea Ceriodaphnia dubia exposed to Triclosan spiked sediments based on standard methods EPA and OECD. The EC50;96H obtained on acute toxicity tests with C. xanthus was 45,26 mg.Kg{sup -1}. The chronic toxicity tests with C. dubia using spiked sediments were performed following the procedure in Burton and MacPherson (1995). A no-observed-effect concentrations and lowest-observed-effect concentration were 5,78 e 6,94 mg.Kg{sup -1}, respectively. (author)

  16. Responses of aquatic organisms to metal pollution in a lowland river in Flanders: A comparison of diatoms and macroinvertebrates

    Energy Technology Data Exchange (ETDEWEB)

    Jonge, Maarten de [Department of Biology, Ecophysiology, Biochemistry and Toxicology Group, University of Antwerp, Groenenborgerlaan 171, B-2020 Antwerp (Belgium)], E-mail: maarten.dejonge@ua.ac.be; Vijver, Bart van de [Department of Bryophytes and Thallophytes, National Botanic Garden of Belgium, Domein van Bouchout, 1860 Meise (Belgium); Blust, Ronny; Bervoets, Lieven [Department of Biology, Ecophysiology, Biochemistry and Toxicology Group, University of Antwerp, Groenenborgerlaan 171, B-2020 Antwerp (Belgium)

    2008-12-15

    The role of macroinvertebrates and diatoms as indicator for metal pollution was investigated by assessing both biota along a metal gradient in the Belgian river the Dommel. Macroinvertebrates and diatoms were sampled in summer and winter and physical-chemical characteristics of the water were measured at four different sample periods and related to sediment characteristics. Although metal concentrations, except cadmium, in the water nowhere exceeded water quality standards, high metal concentrations were measured in the sediment, indicating historical contamination of the Dommel. At the sites that were situated downstream of the pollution source, high levels of conductivity and chloride were measured in the water. Redundancy Analysis (RDA) indicated pH, phosphate and zinc as the significant environmental variables explaining each respectively 7.7%, 11.6% and 22.6% of the macroinvertebrate community composition. Two clusters could be separated, with Gammarus pulex, Leptocerus interruptus, Baetis rhodani and Cloeon dipterum associated with low zinc concentrations and Tubificidae, Asellus aquaticus, Erpobdella sp. and Chironomus thummi-plumosus associated with higher zinc concentrations. Ammonium (10.6%), conductivity (16.5%), chloride (11.4%) and zinc (5.9%) turned out to be significant variables explaining the diatom community structure. Based on physical-chemical differences and species composition, three different groups could be separated. With this Tabellaria flocculosa and Fragilaria capucina var. rumpens were associated with low metal concentrations, Gomphonema parvulum and Nitzschia palea with elevated concentrations and Eolimna minima and Sellaphora seminulum with high zinc concentrations. In conclusion, the diatom community best reflected the metal gradient. With regard to water quality indices, those based on macroinvertebrates best followed the metal pollution gradient and were most strongly correlated with physical-chemical variables of water and

  17. Identification and reassessment of the specific status of some tropical freshwater midges (Diptera: Chironomidae) using DNA barcode data.

    Science.gov (United States)

    Pramual, Pairot; Simwisat, Kusumart; Martin, Jon

    2016-01-01

    Chironomidae are a highly diverse group of insects. Members of this family are often included in programs monitoring the health of freshwater ecosystems. However, a difficulty in morphological identification, particularly of larval stages is the major obstacle to this application. In this study, we tested the efficiency of mitochondrial cytochrome c oxidase I (COI) sequences as the DNA barcoding region for species identification of Chironomidae in Thailand. The results revealed 14 species with a high success rate (>90%) for the correct species identification, which suggests the potential usefulness of the technique. However, some morphological species possess high (>3%) intraspecific genetic divergence that suggests these species could be species complexes and need further morphological or cytological examination. Sequence-based species delimitation analyses indicated that most specimens identified as Chironomus kiiensis, Tokunaga 1936, in Japan are conspecific with C. striatipennis, Kieffer 1912, although a small number form a separate cluster. A review of the descriptions of Kiefferulus tainanus (Kieffer 1912) and its junior synonym, K. biroi (Kieffer 1918), following our results, suggests that this synonymy is probably not correct and that K. tainanus occurs in Japan, China and Singapore, while K. biroi occurs in India and Thailand. Our results therefore revealed the usefulness of DNA barcoding for correct species identification of Chironomidae, particularly the immature stages. In addition, DNA barcodes could also uncover hidden diversity that can guide further taxonomic study, and offer a more efficient way to identify species than morphological analysis where large numbers of specimens are involved, provided the identifications of DNA barcodes in the databases are correct. Our studies indicate that this is not the case, and we identify cases of misidentifications for C. flaviplumus, Tokunaga 1940 and K. tainanus. PMID:27395909

  18. Transfer modelling and toxicity evaluation of the effluent from an installation of cleansing and uranium recovery using a battery of bioassays.

    Science.gov (United States)

    Gagnaire, Béatrice; Boyer, Patrick; Bonzom, Jean-Marc; Lecomte-Pradines, Catherine; Simon, Olivier; Gilbin, Rodolphe

    2011-01-01

    On July 7, 2008, a leak of effluent from an Installation of Cleansing and Uranium Recovery (Tricastin, France) led to the spillage of uranium in a stream. The acute toxicity of the effluent was evaluated, and compared to the toxicity of uranium nitrate in bioassays using several organisms: Chlamydomonas reinhardtii, Daphnia magna, Chironomus riparius and Danio rerio. A sediment bioassay was also performed on C. riparius using water and sediment sampled along the river. Results showed that effluent EC(50) 72 h was 0.65 mg U/l for algae and LC(50) 48 h was 1.67 mg U/l for daphnia, while values obtained for uranium nitrate were higher. The LC(50) 96 h of effluent to C. riparius was 22.7 mg U/l, similar to value for uranium nitrate; the sediment collected was not toxic to C. riparius larvae. The LOEC of effluent and uranium nitrate on HT(50) of D. rerio were similar (0.03 mg U/l), but larvae were more sensitive to uranium nitrate than to effluent. Our results suggest that other substances contained in the effluent could potentially be toxic to wildlife in association with uranium. In parallel, the modelling of the transfers based on uranium measurements in the surface water was used to fill data gaps and assess the impact along the river. These results provided an estimate of exposure conditions that occurred along the river. This approach allowed us to see that the risk to ecosystem during this incident was certainly low and concerned a short period of time, but it could have existed at least for some species. PMID:21107686

  19. Laboratory culture of the freshwater benthic gastropod Bellamya aeruginosa (Reeve) and its utility as a test species for sediment toxicity.

    Science.gov (United States)

    Ma, Taowu; Gong, Shuangjiao; Zhou, Ke; Zhu, Cheng; Deng, Kaidong; Luo, Qinghua; Wang, Zijian

    2010-01-01

    This study aimed to develop original laboratory culture and sediment toxicity testing protocols for the freshwater gastropod Bellamya aeruginosa (Reeve), a new potential species for sediment toxicity testing. B. aeruginosa was successfully cultured with an effective culture system under proposed laboratory conditions. Optimal ad libitum feeding levels for larvae, juveniles, and adults were 2.0, 6.0, and 16.0 mg fish food/(snail x day), respectively. Mean survival rates of juveniles were higher than 90%. The snails could be sexed at 9 weeks of age, and their generation time is approximately 4 months. Reproduction continued all year around; the mean fecundity was 0.55 newborn/(female x day). The utility of this species for bioassays was evaluated in both 10-day and 28-day case studies with artificial sediments. The 10-day LC50 of Cu for larvae was 480 gg/g dry weight (dw), and the lowest observed effects concentration of Cu for survival and growth of larvae was 195 microg/g dw. Survival and growth are reliable indicators of acute toxicity. Larvae accumulated more Cu than adults. B. aeruginosa exhibited a higher sensitivity to Cu exposure than standard test species (Hyalella azteca and Chironomus tentans). The 28-day test of sediment toxicity with adults showed that fecundity was a robust endpoint indicator of reproductive toxicity, and the biochemical endpoints of superoxide dismutase, catalase, and glutathione could be used as sensitive biomarkers for Cu-induced oxidative damage. B. aeruginosa can be therefore recommended as a candidate for the standardization of the freshwater sediment toxicity test protocol.

  20. Toxicity of sediments from lead-zinc mining areas to juvenile freshwater mussels (Lampsilis siliquoidea) compared to standard test organisms

    Science.gov (United States)

    Besser, John M.; Ingersoll, Christopher G.; Brumbaugh, William G.; Kemble, Nile E.; May, Thomas W.; Wang, Ning; MacDonald, Donald D.; Roberts, Andrew D.

    2015-01-01

    Sediment toxicity tests compared chronic effects on survival, growth, and biomass of juvenile freshwater mussels (28-d exposures with Lampsilis siliquoidea) to the responses of standard test organisms—amphipods (28-d exposures with Hyalella azteca) and midges (10-d exposures with Chironomus dilutus)—in sediments from 2 lead–zinc mining areas: the Tri-State Mining District and Southeast Missouri Mining District. Mussel tests were conducted in sediments sieved to <0.25 mm to facilitate recovery of juvenile mussels (2–4 mo old). Sediments were contaminated primarily with lead, zinc, and cadmium, with greater zinc and cadmium concentrations in Tri-State sediments and greater lead concentrations in southeast Missouri sediments. The frequency of highly toxic responses (reduced 10% or more relative to reference sites) in Tri-State sediments was greatest for amphipod survival (25% of samples), midge biomass (20%), and mussel survival (14%). In southeast Missouri sediments, the frequency of highly toxic samples was greatest for mussel biomass (25%) and amphipod biomass (13%). Thresholds for metal toxicity to mussels, expressed as hazard quotients based on probable effect concentrations, were lower for southeast Missouri sediments than for Tri-State sediments. Southeast Missouri sites with toxic sediments had 2 or fewer live mussel taxa in a concurrent mussel population survey, compared with 7 to 26 taxa at reference sites. These results demonstrate that sediment toxicity tests with juvenile mussels can be conducted reliably by modifying existing standard methods; that the sensitivity of mussels to metals can be similar to or greater than standard test organisms; and that responses of mussels in laboratory toxicity tests are consistent with effects on wild mussel populations.

  1. Influence of bioturbation on the biogeochemistry of the sediment in the littoral zone of an acidic mine pit lake

    Directory of Open Access Journals (Sweden)

    S. Lagauzère

    2010-10-01

    Full Text Available In the last decades, the mining exploitation of large areas in Lusatia (South-eastern Germany but also in other mining areas worldwide has led to the formation of hundreds of pit lakes. Pyrite oxidation in the surrounding dumps makes many such lakes extremely acidic (pH < 3. The biogeochemical functioning of these lakes is mainly governed by cycling of iron. This represents a relevant ecological problem and intensive research has been conducted to understand the involved biogeochemical processes and develop bioremediation strategies. Despite some studies reporting the presence of living organisms (mostly bacteria, algae, and macro-invertebrates under such acidic conditions, and their trophic interactions, their potential impact on the ecosystem functioning was poorly investigated. The present study aimed to assess the influence of chironomid larvae on oxygen dynamics and iron cycle in the sediment of acidic pit lakes. In the Mining Lake 111, used as a study case since 1996, Chironomus crassimanus (Insecta, Diptera is the dominant benthic macro-invertebrate species and occurs at relatively high abundances in shallow water. A 16-day laboratory experiment using microcosms combined with high resolution measurements (DET gel probes and O2 microsensors was carried out. The burrowing activity of C. crassimanus larvae induced a 3-fold increase of the oxygen consumption by sediment, and stimulated the mineralization of organic matter in the upper layers of the sediment. The iron cycle was also impacted (e.g. lower rates of reduction and oxidation, increase of iron-oxidizing bacteria abundance, stimulation of mineral formation but with no significant effect on the iron flux at the sediment-water interface, and thus on the water acidity budget. This work provides the first assessment of bioturbation in an acidic mining lake and shows that its influence on biogeochemistry cannot be neglected.

  2. Influence of bioturbation on the biogeochemistry of littoral sediments of an acidic post-mining pit lake

    Directory of Open Access Journals (Sweden)

    S. Lagauzère

    2011-02-01

    Full Text Available In the last decades, the mining exploitation of large areas in Lusatia (Eastern Germany but also in other mining areas worldwide has led to the formation of hundreds of pit lakes. Pyrite oxidation in the surrounding dumps makes many such lakes extremely acidic (pH < 3. The biogeochemical functioning of these lakes is mainly governed by cycling of iron. This represents a relevant ecological problem and intensive research has been conducted to understand the involved biogeochemical processes and develop bioremediation strategies. Despite some studies reporting the presence of living organisms (mostly bacteria, algae, and macro-invertebrates under such acidic conditions, and their trophic interactions, their potential impact on the ecosystem functioning was poorly investigated. The present study aimed to assess the influence of chironomid larvae on oxygen dynamics and iron cycle in the sediment of acidic pit lakes. In the Mining Lake 111, used as a study case since 1996, Chironomus crassimanus (Insecta, Diptera is the dominant benthic macro-invertebrate species and occurs at relatively high abundances in shallow water. A 16-day laboratory experiment using microcosms combined with high resolution measurements (DET gel probes and O2 microsensors was carried out. The burrowing activity of C. crassimanus larvae induced a 3-fold increase of the diffusive oxygen uptake by sediment, indicating a stimulation of the mineralization of organic matter in the upper layers of the sediment. The iron cycle was also impacted (e.g. lower rates of reduction and oxidation, increase of iron-oxidizing bacteria abundance, stimulation of mineral formation but with no significant effect on the iron flux at the sediment-water interface, and thus on the water acidity budget. This work provides the first assessment of bioturbation in an acidic mining lake and shows that its influence on biogeochemistry cannot be neglected.

  3. Assessing sediment toxicity and arsenite concentration with bacterial and traditional methods

    Energy Technology Data Exchange (ETDEWEB)

    Petaenen, T.; Lyytikaeinen, M.; Lappalainen, J.; Romantschuk, M.; Kukkonen, J.V.K

    2003-04-01

    Different methods can be used to complement each other. - Three sediment samples LP (pool where logs are stored), LF (brook through landfill area), KN (Kaskesniemi) which is in Lake Pyhaeselkae downstream from the mill, were taken from an old sawmill area and one from the unpolluted Lake Hoeytiaeinen. The arsenite concentration was measured by GFAAS and two arsenite biosensing bacterial strains Pseudomonas fluorescens OS8 (pTPT31) and Escherichia coli MC1061 (pTOO31). The toxicity of sediment and pore water samples was determined by using luminescent bacteria (Flash test) and, further, whole sediment toxicity was measured using 10 days growth test and 50 days emergency test with midges (Chironomus riparius). With the flash test a lowered EC50 value was found only in sediment LF (EC50=0.17 v/v%). The Flash test indicated that all sediment samples taken from the sawmill area were highly toxic to bacteria, whereas growth and the emergence of chironomids showed no effects in other samples than LF. The midges tolerate well the contaminated environment. In contrast, bioavailability of arsenite of sediment samples KN and LF was quite high determined using the biosensor-strains in a direct contact assay. The bioavailable fraction of sediment LP was 6-10% out of the total arsenite concentration obtained with GFAAS (0.46-0.77 {mu}g g{sup -1} dw). The results show that the choice of analysis method grossly affects the outcome without any of the method giving an incorrect result. Different methods measure different parameters of a toxic sample and can thus be used to complement each other.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2005-09-01

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

  5. Toxicity of CeO2 nanoparticles at different trophic levels--effects on diatoms, chironomids and amphibians.

    Science.gov (United States)

    Bour, Agathe; Mouchet, Florence; Verneuil, Laurent; Evariste, Lauris; Silvestre, Jérôme; Pinelli, Eric; Gauthier, Laury

    2015-02-01

    The aim of the present work is to provide wider information on the toxicity of cerium dioxide nanoparticles (CeO2 NPs) in aquatic environments, by studying the toxicity of two types of CeO2 NPs for four species (diatoms Nitzschia palea, the sediment-dwelling invertebrate Chironomus riparius, and the amphibian larvae Xenopus laevis and Pleurodeles waltl.). The two types of CeO2 NPs have different intrinsic properties: some of them are small citrate-coated spheres (2-5 nm), and the others are larger uncoated plates (20-60 nm). Acute toxicity (mortality at 48 or 96 h, depending on the test-organism) was assessed for the four species, from 0.1 to 100 mg L(-1) of NPs. Sub-lethal effects were assessed on chironomids exposed between 0.01 and 1 mg L(-1) of NPs. Mortality, growth inhibition and genotoxic effects were evaluated on amphibian larvae from 0.1 to 10 mg L(-1). Results reveal that no acute toxicity occurs on any species after short exposures, even at the highest concentrations. Mortality (35%) is observed on Xenopus larvae after 12d of exposure at the highest concentration of one type of NPs. No significant effects were observed on chironomids during chronic exposure. Xenopus larvae growth was inhibited from 1 mg L(-1) of both NPs while growth inhibition is observed on Pleurodeles only at the highest concentration of one type of NPs. No genotoxicity was observed on Xenopus but Pleurodeles exhibited dose-dependent genotoxic effects when exposed to one type of NPs. Observed differences in toxicity are discussed focusing on the studied compartment, routes of exposure, species and NPs.

  6. Chironomidae and Oligochaeta for water quality evaluation in an urban river in southeastern Brazil.

    Science.gov (United States)

    Rosa, Beatriz Jabour Figueiraujo Vescovi; Rodrigues, Luciana Falci Theza; de Oliveira, Gilmar Simões; da Gama Alves, Roberto

    2014-11-01

    Considering the importance of benthic macroinvertebrates for diagnosis of variations in the ecological conditions of aquatic habitats, the aim of this study was to investigate the structure of the Chironomidae and Oligochaeta assemblages along an organic pollution gradient. The fauna specimens were obtained with the use of artificial substrates, and the environmental variables were recorded at five sites of the São Lourenço River, during 12 months. Metrics of the assemblage and detrended correspondence analysis were used to verify the response of the fauna to the pollution gradient. Procrustes analysis was used to verify whether the data on the Chironomidae and Oligochaeta assemblages, as well as the taxonomic and numerical resolution of these groups, provide similar results in relation to the pollution gradient. The richness, evenness, and taxonomic composition of the Chironomidae and Oligochaeta assemblages varied significantly among the collection sites, with distinct conservation conditions. Genera of the subfamilies Orthocladiinae and Tanypodinae were associated with the sites upstream of the urban area, where the dissolved oxygen levels are higher. Species of Oligochaeta and the genus Chironomus were associated with more organically polluted sites. No concordance was observed in the response of the Chironomidae and Oligochaeta assemblages in relation to the environmental variables, indicating the need to use both groups in biomonitoring studies. On the other hand, both the data on composition (presence or absence) and those on the lowest taxonomic resolution (abundance of subfamilies) were effective to diagnose the pollution gradient in the river studied. Therefore, when the environmental conditions along a river's gradient are contrasting, we suggest the use of the lowest taxonomic resolution of Chironomidae and Oligochaeta in biomonitoring. That procedure considerably reduces the assessment time, besides being a method that can be used by people not

  7. Weight-of-evidence approach in assessment of ecotoxicological risks of acid sulphate soils in the Baltic Sea river estuaries.

    Science.gov (United States)

    Wallin, Jaana; Karjalainen, Anna K; Schultz, Eija; Järvistö, Johanna; Leppänen, Matti; Vuori, Kari-Matti

    2015-03-01

    Acidity and leaching of metals from acid sulphate soils (ASSs) impair the water quality of receiving surface waters. The largest ASS areas in Europe are found in the coasts of the northern Baltic Sea. We used weight-of-evidence (WoE) approach to assess potential risks in 14 estuary sites affected by ASS in the Gulf of Finland, northern Baltic Sea. The assessment was based on exposure and effect profiles utilizing sediment and water metal concentrations and concurrent pH variation, sediment toxicity tests using the luminescent bacterium Vibrio fischeri and the midge Chironomus riparius, and the ecological status of benthic macroinvertebrate communities. Sediment metal concentrations were compared to national sediment quality criteria/guidelines, and water metal concentrations to environmental quality standards (EQSs). Hazard quotients (HQs) were established for maximum aluminium, cadmium and zinc concentrations at low pH based on applicable US EPA toxicity database. Sediment metal concentrations were clearly elevated in most of the studied estuaries. The EQS of cadmium (0.1 μg/l) was exceeded in 3 estuaries out of 14. The pH-minima were below the national threshold value (5.5) between good and satisfactory water quality in 10 estuaries. V. fischeri bioluminescence indicated toxicity of the sediments but toxic response was not observed in the C. riparius emergence test. Benthic invertebrate communities were deteriorated in 6 out of 14 sites based on the benthic invertebrate quality index. The overall ecotoxicological risk was assessed as low in five, moderate in three and high in five of the estuary sites. The risk assessment utilizing the WoE approach indicated that harmful effects of ASSs are likely to occur in the Baltic Sea river estuaries located at the ASS hotspot area. PMID:25506908

  8. Development of methods for evaluating toxicity to freshwater ecosystems.

    Science.gov (United States)

    Girling, A E; Pascoe, D; Janssen, C R; Peither, A; Wenzel, A; Schäfer, H; Neumeier, B; Mitchell, G C; Taylor, E J; Maund, S J; Lay, J P; Jüttner, I; Crossland, N O; Stephenson, R R; Persoone, G

    2000-02-01

    This article presents a summary of a collaborative research program involving five European research groups, that was partly funded by the European Commission under its Environmental Research Program. The objective of the program was to develop aquatic toxicity tests that could be used to obtain data for inclusion at Level 2 of the Risk Evaluation Scheme for the Notification of Substances as required by the 7th Amendment to EC Directive 79/831/EEC. Currently only a very limited number of test methods have been described that can be used for this purpose and these are based on an even smaller number of test species. Tests based upon algae (Chlamydomonas reinhardi, Scenedesmus subspicatus, and Euglena gracilis), protozoa (Tetrahymena pyriformis), rotifera (Brachionus calyciflorus), crustacea (Gammarus pulex), and diptera (Chironomus riparius) were developed. The tests encompassed a range of end points and were evaluated against four reference chemicals: lindane, 3, 4-dichloroaniline (DCA), atrazine, and copper. The capacity of the tests to identify concentrations that are chronically toxic in the field was addressed by comparing the effects threshold concentrations determined in the laboratory tests with those determined for similar and/or related species and end points in stream and pond mesocosm studies. The lowest no-observed-effect concentrations (NOEC), EC(x), or LC(x) values obtained for lindane, atrazine, and copper were comparable with the lowest values obtained in the mesocosms. The lowest chronic NOEC determined for DCA using the laboratory tests was approximately 200 times higher than the lowest NOEC in the mesocosms. PMID:10648133

  9. Benthic fauna of extremely acidic lakes (pH 2-3)

    Energy Technology Data Exchange (ETDEWEB)

    Rodrigues, G.G.

    2001-07-01

    The structure of the benthic invertebrate communities were investigated in terms of composition, abundance, and biomass from extremely acidic lakes with pH values from 2 to 3 in areas where coal was intensively mined in the Lusatian region in the eastern region of Germany. Benthic invertebrates colonisation on leaves and the breakdown rate processing of the three deciduous leaf: Betula pendula (birch), Fraxinus excelsior (ash), and Juglans regia (walnut) were investigated. Also, the main key-species of these acidic environments were investigated, in terms of description of pupal exuviae of Chironomus crassimanus and the feeding habit of this acid-resistant species through analysis of their gut content. The benthic food web in extremely acidic mining Lusatian lakes is very short in terms of species richness, trophic relationship, guilds and functional feeding groups. Collector-filters and scraper-grazers were absent in extremely acidic mining lakes (AML 107, AML 111 and AML 117). Shredders as Limnophyes minimus (Diptera, Chironomidae, Orthocladiinae) and Hydrozetes lacustris (Acari, Hydrozetidae) occurred in low abundance in AML 107 and AML 111, and it may be in response to slow leaf breakdown process in these ecosystems, except in AML 117 where the H. lacustris contributed most to ecosystems functioning via the processing of litter. Aquatic insects as Sialis lutaria (Megaloptera, Sialidae), Orectochilus villosus (Coleoptera, Gyrinidae), Coenagrion mercuriale (Odonata, Coenagrionidae), and Phryganeidae (Trichoptera) are the top-predators of these ecosystems. They did not depend on the level of pH in the lakes, but on the availability of food resources. (orig.)

  10. First phase of macroinvertebrate repopulation of Lake Orta (Buccione Basin after liming

    Directory of Open Access Journals (Sweden)

    Angela BOGGERO

    2001-02-01

    Full Text Available The research described here was performed during 1993 and 1994 in the context of studies on the recovery of Lake Orta from acidification after the liming conducted from May 1989 to June 1990. The causes of the pollution were due to the oxidation of ammonium sulphate discharged from a factory producing rayon by a cupro-ammoniacal method and to the loads of heavy metals (Cu, Cr, Ni, Zn derived from plating factories. One year after liming, an increase in pH and a marked decrease in metal concentrations were observed, and as a consequence some qualitative and quantitative changes were observed in 1992-93 in the planctonic communities and in the littoral macrobenthic fauna. This paper presents qualitative and quantitative data on macrobenthos collected along a transect between the littoral and the maximal depth in the Buccione Basin, which was directly affected by the effluents of the rayon factory. The data revealed some quantitative repopulation of this community, especially along the littoral. Qualitatively, however, the macrobenthos was still quite poor, consisting essentially of Oligochaeta and Diptera Chironomidae. The former were rare and mainly represented by Naididae between 15 and 22 m, while the Tubificidae were well represented in the littoral and the profundal zones. As regards the Chironomidae, the genera Procladius and Chironomus gr. thummi extended as far as the maximum depth, while others, such as Ablabesmyia, Parakiefferiella bathophila and Dicrotendipes gr. nervosus were mostly distributed in the littoral layers. Among the other taxonomic groups only the Trichoptera and the Diptera Ceratopogonidae were quantitatively significant. However, many systematic entities typical of the less polluted Italian subalpine lakes are still absent. In fact, the colonisation of Lake Orta by macrobenthic organisms is still influenced by the increased concentrations of heavy metals in the sediment precipitated from the water column. The research

  11. Deriving freshwater quality criteria for iron, lead, nickel, and zinc for protection of aquatic life in Malaysia.

    Science.gov (United States)

    Shuhaimi-Othman, M; Nadzifah, Y; Nur-Amalina, R; Umirah, N S

    2012-01-01

    Freshwater quality criteria for iron (Fe), lead (Pb), nickel (Ni), and zinc (Zn) were developed with particular reference to aquatic biota in Malaysia, and based on USEPA's guidelines. Acute toxicity tests were performed on eight different freshwater domestic species in Malaysia which were Macrobrachium lanchesteri (prawn), two fish: Poecilia reticulata and Rasbora sumatrana, Melanoides tuberculata (snail), Stenocypris major (ostracod), Chironomus javanus (midge larvae), Nais elinguis (annelid), and Duttaphrynus melanostictus (tadpole) to determine 96 h LC(50) values for Fe, Pb, Ni, and Zn. The final acute value (FAV) for Fe, Pb, Ni, and Zn were 74.5, 17.0, 165, and 304.9 μg L(-1), respectively. Using an estimated acute-to-chronic ratio (ACR) of 8.3, the value for final chronic value (FCV) was derived. Based on FAV and FCV, a criterion maximum concentration (CMC) and a criterion continuous concentration (CCC) for Fe, Pb, Ni, and Zn that are 37.2, 8.5, 82.5, and 152.4 μg L(-1) and 9.0, 2.0, 19.9, and 36.7 μg L(-1), respectively, were derived. The results of this study provide useful data for deriving national or local water quality criteria for Fe, Pb, Ni, and Zn based on aquatic biota in Malaysia. Based on LC(50) values, this study indicated that N. elinguis, M. lanchesteri, N. elinguis, and R. sumatrana were the most sensitive to Fe, Pb, Ni, and Zn, respectively. PMID:22919358

  12. Deriving Freshwater Quality Criteria for Iron, Lead, Nickel, and Zinc for Protection of Aquatic Life in Malaysia

    Directory of Open Access Journals (Sweden)

    M. Shuhaimi-Othman

    2012-01-01

    Full Text Available Freshwater quality criteria for iron (Fe, lead (Pb, nickel (Ni, and zinc (Zn were developed with particular reference to aquatic biota in Malaysia, and based on USEPA’s guidelines. Acute toxicity tests were performed on eight different freshwater domestic species in Malaysia which were Macrobrachium lanchesteri (prawn, two fish: Poecilia reticulata and Rasbora sumatrana, Melanoides tuberculata (snail, Stenocypris major (ostracod, Chironomus javanus (midge larvae, Nais elinguis (annelid, and Duttaphrynus melanostictus (tadpole to determine 96 h LC50 values for Fe, Pb, Ni, and Zn. The final acute value (FAV for Fe, Pb, Ni, and Zn were 74.5, 17.0, 165, and 304.9 μg L−1, respectively. Using an estimated acute-to-chronic ratio (ACR of 8.3, the value for final chronic value (FCV was derived. Based on FAV and FCV, a criterion maximum concentration (CMC and a criterion continuous concentration (CCC for Fe, Pb, Ni, and Zn that are 37.2, 8.5, 82.5, and 152.4 μg L−1 and 9.0, 2.0, 19.9, and 36.7 μg L−1, respectively, were derived. The results of this study provide useful data for deriving national or local water quality criteria for Fe, Pb, Ni, and Zn based on aquatic biota in Malaysia. Based on LC50 values, this study indicated that N. elinguis, M. lanchesteri, N. elinguis, and R. sumatrana were the most sensitive to Fe, Pb, Ni, and Zn, respectively.

  13. Examining waterborne and dietborne routes of exposure and their contribution to biological response patterns in fathead minnow (Pimephales promelas).

    Science.gov (United States)

    Rozon-Ramilo, Lisa D; Dubé, Monique G; Squires, Allison J; Niyogi, Som

    2011-10-01

    The objectives of the current study were: (i) to gain a better understanding of the relative importance of water and diet as routes of exposure causing toxicity in fathead minnow (FHM) exposed to metal mining effluents (MME) using a full factorial water/food experimental design (Experiment 1), and (ii) to assess differences in the effects of food quality on toxicity by comparing FHM fed both a live and frozen diet of Chironomus dilutus (Experiment 2). The results showed significant increases in general water quality parameters (e.g., hardness, conductivity) and various metals in the effluent treatment waters compared to control waters, with maximum increase seen in the multi-trophic streams. Metals accumulation (Rb, Al, Se, Sr, Tl, Ce, Co, Cu, Pb) effects of both waterborne and multi-trophic exposures were significant in one or more fathead minnow tissue type (muscle, gonads, liver, larvae) relative to those in the control systems. Condition factor and liver somatic index (LSI) of FHM were also significantly affected in both exposures by one or both routes of exposure (water and/or diet). In addition, cumulative total egg production and cumulative spawning events were significantly affected by both waterborne and dietborne exposures, with maximum effect found in the multi-trophic streams. These results suggest that under environmentally relevant exposure conditions, trophic transfer of metals may lead to greater reproductive effects and increased metal toxicity in fish. It also indicates that metals are assimilated in tissues differently depending on the quality of the food (live vs. frozen). Overall, it appears that the multi-trophic bioassay provides an important link between the laboratory and field, which may allow for a more realistic assessment of the true impact of MME's in the environment. PMID:21888872

  14. TiO2 nanoparticles for the remediation of eutrophic shallow freshwater systems: Efficiency and impacts on aquatic biota under a microcosm experiment.

    Science.gov (United States)

    Bessa da Silva, Márcia; Abrantes, Nelson; Nogueira, Verónica; Gonçalves, Fernando; Pereira, Ruth

    2016-09-01

    The application of nanomaterials (NMs) in the remediation of eutrophic waters, particularly in the control of internal loading of nutrients, has been started, but limited investigations evaluated the effectiveness of these new treatment approaches and of their potential impacts on species from shallow freshwater lakes. The present work investigated, under a microcosm experiment, the application of a TiO2 nanomaterial both for reducing nutrient (mainly phosphorus and nitrogen forms) desorption and release from sediments (preventive treatment-PT) and for eliminating algal blooms (remediation treatment-RT). Furthermore, we also intended to assess the potential impacts of nano-TiO2 application on key freshwater species. The results showed the effectiveness of nano-TiO2 in controlling the release of phosphates from surface sediment and the subsequent reduction of total phosphorus in the water column. A reduction in total nitrogen was also observed. Such changes in nutrient dynamics contributed to a progressive inhibition of development of algae after the application of the NM in PT microcosms. Concerning the ability of nano-TiO2 to interact with algal cells, this interaction has likely occurred, mainly in RT, enhancing the formation of aggregates and their rapid settlement, thus reducing the algal bloom. Both treatments caused deleterious effects on freshwater species. In PT, Daphnia magna and Lemna minor showed a significant inhibition of several endpoints. Conversely, no inhibitory effect on the growth of Chironomus riparius was recorded. In opposite, C. riparius was the most affected species in RT microcosms. Such difference was probably caused by the formation of larger TiO2-algae aggregates in RT, under a high algal density, that rapidly settled in the sediment, becoming less available for pelagic species. In summary, despite the effectiveness of both treatments in controlling internal nutrient loading and in the mitigating algal bloom episodes, their negative

  15. Single-step biosynthesis and characterization of silver nanoparticles using Zornia diphylla leaves: A potent eco-friendly tool against malaria and arbovirus vectors.

    Science.gov (United States)

    Govindarajan, Marimuthu; Rajeswary, Mohan; Muthukumaran, Udaiyan; Hoti, S L; Khater, Hanem F; Benelli, Giovanni

    2016-08-01

    Mosquitoes (Diptera: Culicidae) are vectors of important pathogens and parasites, including malaria, dengue, chikungunya, Japanese encephalitis, lymphatic filariasis and Zika virus. The application of synthetic insecticides causes development of resistance, biological magnification of toxic substances through the food chain, and adverse effects on the environment and human health. In this scenario, eco-friendly control tools of mosquito vectors are a priority. Here single-step fabrication of silver nanoparticles (AgNP) using a cheap aqueous leaf extract of Zornia diphylla as reducing and capping agent pf Ag(+) ions has been carried out. Biosynthesized AgNP were characterized by UV-visible spectrophotometry, Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy-dispersive spectroscopy (EDX) and X-ray diffraction analysis (XRD). The acute toxicity of Z. diphylla leaf extract and biosynthesized AgNP was evaluated against larvae of the malaria vector Anopheles subpictus, the dengue vector Aedes albopictus and the Japanese encephalitis vector Culex tritaeniorhynchus. Both the Z. diphylla leaf extract and Ag NP showed dose dependent larvicidal effect against all tested mosquito species. Compared to the leaf aqueous extract, biosynthesized Ag NP showed higher toxicity against An. subpictus, Ae. albopictus, and Cx. tritaeniorhynchus with LC50 values of 12.53, 13.42 and 14.61μg/ml, respectively. Biosynthesized Ag NP were found safer to non-target organisms Chironomus circumdatus, Anisops bouvieri and Gambusia affinis, with the respective LC50 values ranging from 613.11 to 6903.93μg/ml, if compared to target mosquitoes. Overall, our results highlight that Z. diphylla-fabricated Ag NP are a promising and eco-friendly tool against larval populations of mosquito vectors of medical and veterinary importance, with negligible toxicity against other non-target organisms.

  16. Responses of aquatic organisms to metal pollution in a lowland river in Flanders: A comparison of diatoms and macroinvertebrates

    International Nuclear Information System (INIS)

    The role of macroinvertebrates and diatoms as indicator for metal pollution was investigated by assessing both biota along a metal gradient in the Belgian river the Dommel. Macroinvertebrates and diatoms were sampled in summer and winter and physical-chemical characteristics of the water were measured at four different sample periods and related to sediment characteristics. Although metal concentrations, except cadmium, in the water nowhere exceeded water quality standards, high metal concentrations were measured in the sediment, indicating historical contamination of the Dommel. At the sites that were situated downstream of the pollution source, high levels of conductivity and chloride were measured in the water. Redundancy Analysis (RDA) indicated pH, phosphate and zinc as the significant environmental variables explaining each respectively 7.7%, 11.6% and 22.6% of the macroinvertebrate community composition. Two clusters could be separated, with Gammarus pulex, Leptocerus interruptus, Baetis rhodani and Cloeon dipterum associated with low zinc concentrations and Tubificidae, Asellus aquaticus, Erpobdella sp. and Chironomus thummi-plumosus associated with higher zinc concentrations. Ammonium (10.6%), conductivity (16.5%), chloride (11.4%) and zinc (5.9%) turned out to be significant variables explaining the diatom community structure. Based on physical-chemical differences and species composition, three different groups could be separated. With this Tabellaria flocculosa and Fragilaria capucina var. rumpens were associated with low metal concentrations, Gomphonema parvulum and Nitzschia palea with elevated concentrations and Eolimna minima and Sellaphora seminulum with high zinc concentrations. In conclusion, the diatom community best reflected the metal gradient. With regard to water quality indices, those based on macroinvertebrates best followed the metal pollution gradient and were most strongly correlated with physical-chemical variables of water and

  17. Starvation metabolism of two common species of chironomids in Biandantang Lake

    Institute of Scientific and Technical Information of China (English)

    LI Xiaoyu; YAN Yunjun

    2006-01-01

    Starvation metabolism is one of the important parts of respiration for normal activities of chironomids. During April 1996 to March 1997, the relationships of starvation metabolism and temperature, body weight of two common chironomids in Biandantang Lake were carefully investigated. The results showed relationship between starvation metabolism (R, mgO2/ind.d) and body weight (Ww, mg wet wt) was: Chironomus plumosus, lgR=-2.573+1.021lgWw (5℃), lgR=-2.710+1.354lgWw (10℃), lgR=-1.824+0.823lgWw (15℃), lgR=-1.364+0.442lgWw (20℃), lgR=-2.763+1.517lgWw (25℃); and Tokunagayusurika akamusi, lgR=-2.390+0.752lgWw (5 ℃ ), lgR=-1.978+0.710lgWw (10 ℃ ), lgR=-1.676+0.648lgWw (15℃), lgR=-1.517+0.650lgWw (20℃), lgR=-2.434+1.290lgWw (25℃). Relationship of starvation metabolism and temperature (T, ℃) was: C. plumosus, R = -0.051 + 0.021T - 0.0006T2; T.akamusi, R= -0.051 + 0.021T- 0.0006T2. The complex relationship of the three parameters was: C. plumosus, R=0.0098Ww0.3882e0.1068T; T. akamusi, R=0.0012Ww1.1936e0.0711T. With the above regressions, the estimated annual starvation metabolisms of the two chironomid species in Biandantang Lake were: C.plumosus, 24.2791 kJ/m2.a; T. akamusi, 8.7864 kJ/m2.a, respectively. This provides a firm foundation for the comparative study of bioenergetics of the chironomids.

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

    Science.gov (United States)

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

    2008-01-01

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

  19. Does water level affect benthic macro-invertebrates of a marginal lake in a tropical river-reservoir transition zone?

    Science.gov (United States)

    Zerlin, R A; Henry, R

    2014-05-01

    Benthic macro-invertebrates are important components of freshwater ecosystems which are involved in ecological processes such as energy transfer between detritus and consumers and organic matter recycling. The aim of this work was to investigate the variation in organism richness, diversity and density of benthic fauna during the annual cycle in Camargo Lake, a lake marginal to Paranapanema River, southeast Brazil. The correlation of environmental factors with community attributes of the macro-benthic fauna was assessed. Since Camargo Lake is connected to the river, we tested the hypothesis that water level variation is the main regulating factor of environmental variables and of the composition and abundance of benthic macro-invertebrates. The results indicated that lake depth varied with rainfall, being the highest at the end of the rising water period and the lowest at the beginning of this period. The sediment granulometry was more heterogeneous at the bottom of the lake by the end of the high water period. The benthic macro-invertebrate fauna was composed by 15 taxa. The Diptera order was represented by seven taxa and had greater richness in relation to other taxa. This group was responsible for 60% of the total abundance of organisms, followed by Ephemeroptera (22%) and Anellida (16%). Significant differences were observed over time in total richness and, in density of Narapa bonettoi, Chaoborus, Ablabesmyia gr. annulata, Chironomus gigas, Larsia fittkau, and Procladius sp. 2. Total taxa richness correlated negatively with water pH, transparency, conductivity, and bottom water oxygen. Higher positive correlations were found between the densities of some taxa and bottom water oxygen, conductivity and very fine sand, silt + clay of sediment, while negative correlations were recorded with organic matter, and fine, medium and coarse sand, bottom water temperature, mean temperature and rainfall. The significant temporal difference in water level was associated

  20. Tolerance of freshwater test organisms to formulated sediments for use as control materials in whole-sediment toxicity tests

    Science.gov (United States)

    Kemble, N.E.; Dwyer, F.J.; Ingersoll, C.G.; Dawson, T.D.; Norberg-King, T. J.

    1999-01-01

    A method is described for preparing formulated sediments for use in toxicity testing. Ingredients used to prepare formulated sediments included commercially available silt, clay, sand, humic acid, dolomite, and ??- cellulose (as a source of organic carbon). ??-Cellulose was selected as the source of organic carbon because it is commercially available, consistent from batch to batch, and low in contaminant concentrations. The tolerance of freshwater test organisms to formulated sediments for use as control materials in whole-sediment toxicity testing was evaluated. Sediment exposures were conducted for 10 d with the amphipod Hyalella azteca, the midges Chironomus riparius and C. tentans, and the oligochaete Lumbriculus variegatus and for 28 d with H. azteca. Responses of organisms in formulated sediments was compared with a field-collected control sediment that has routinely been used to determine test acceptability. Tolerance of organisms to formulated sediments was evaluated by determining responses to varying levels of ??-cellulose, to varying levels of grain size, to evaluation of different food types, or to evaluation of different sources of overlying water. In the 10-d exposures, survival of organisms exposed to the formulated sediments routinely met or exceeded the responses of test organisms exposed to the control sediment and routinely met test acceptability criteria required in standard methods. Growth of amphipods and oligochaetes in 10-d exposures with formulated sediment was often less than growth of organisms in the field-collected control sediment. Additional research is needed, using the method employed to prepare formulated sediment, to determine if conditioning formulated sediments before starting 10-d tests would improve the growth of amphipods. In the 28-d exposures, survival of H. azteca was low when reconstituted water was used as the source of overlying water. However, when well water was used as the source of overlying water in 28-d exposures

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

    Science.gov (United States)

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

    2016-01-01

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

  2. Acute and chronic toxicity of sodium sulfate to four freshwater organisms in water-only exposures

    Science.gov (United States)

    Wang, Ning; Consbrock, Rebecca A.; Ingersoll, Christopher G.; Hardesty, Douglas K.; Brumbaugh, William G.; Hammer, Edward J.; Bauer, Candice R.; Mount, David R.

    2015-01-01

    The acute and chronic toxicity of sulfate (tested as sodium sulfate) was determined in diluted well water (hardness of 100 mg/L and pH 8.2) with a cladoceran (Ceriodaphnia dubia; 2-d and 7-d exposures), a midge (Chironomus dilutus; 4-d and 41-d exposures), a unionid mussel (pink mucket, Lampsilis abrupta; 4-d and 28-d exposures), and a fish (fathead minnow, Pimephales promelas; 4-d and 34-d exposures). Among the 4 species, the cladoceran and mussel were acutely more sensitive to sulfate than the midge and fathead minnow, whereas the fathead minnow was chronically more sensitive than the other 3 species. Acute-to-chronic ratios ranged from 2.34 to 5.68 for the 3 invertebrates but were as high as 12.69 for the fish. The fathead minnow was highly sensitive to sulfate during the transitional period from embryo development to hatching in the diluted well water, and thus, additional short-term (7- to 14-d) sulfate toxicity tests were conducted starting with embryonic fathead minnow in test waters with different ionic compositions at a water hardness of 100 mg/L. Increasing chloride in test water from 10 mg Cl/L to 25 mg Cl/L did not influence sulfate toxicity to the fish, whereas increasing potassium in test water from 1mg K/L to 3mg K/L substantially reduced the toxicity of sulfate. The results indicate that both acute and chronic sulfate toxicity data, and the influence of potassium on sulfate toxicity to fish embryos, need to be considered when environmental guidance values for sulfate are developed or refined.

  3. The status of toxicity tests with sediment in Brazil

    Energy Technology Data Exchange (ETDEWEB)

    Araujo, R.P.A. [Companhia de Tecnologia e Saneamento Ambiental, Sao Paulo (Brazil)

    1995-12-31

    The earliest studies in Brazil aiming to evaluate sediment quality through toxicity tests started in the beginning of the 80`s. These were developed by the Environmental Sanitation Agency of Sao Paulo State (CETESB) in Cubatao River and Billings Reservoir, which are located in industrialized and populous regions. Elutriate phase sediment toxicity tests were run with Daphnia similis. In the Cubatao River Basin the combination of toxicity, chemistry data and benthic community structure provided clear indications of sites with different levels of pollution. At this time there was a consensus that the study of a complex compartment such as sediment needed improvements in sampling and analysis procedures. Only in the 90`s the investigations involving sediment toxicity assessment were resumed by CETESB, and it was clear that integrative studies were needed in order to make environmental quality assessment. This kind of studies were conducted by CETESB in some highly polluted areas of Sao Paulo State, Ceriodaphnia dubia and Photobacterium phosphoreum interstitial water tests and Hyalella sp whole sediment tests were run, and the results correlated with several sediment organic and inorganic contaminants. The Sediment Quality Triad proposed by Chapman was applied in one of these studies. This approach was extremely useful in interpreting the data. At the same time marine sediment toxicity tests were developed by CETESB in collaboration with Sao Paulo University, and tests were run with the amphipods Tiburonella viscana, Battyporeiapus bisetosus; tanaidacean Kalliapseudes shubarti and the echinoderm Lytechinus variegatus. The embryo test with L. variegatus was the most adequate in these studies. Nowadays there are other groups in some universities developing sediment toxicity tests with Hyalella and Chironomus in response to a growing concern in Brazil to establish adequate sediment quality assessment guidelines.

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

    Science.gov (United States)

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

    2011-01-01

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

  5. Single-step biosynthesis and characterization of silver nanoparticles using Zornia diphylla leaves: A potent eco-friendly tool against malaria and arbovirus vectors.

    Science.gov (United States)

    Govindarajan, Marimuthu; Rajeswary, Mohan; Muthukumaran, Udaiyan; Hoti, S L; Khater, Hanem F; Benelli, Giovanni

    2016-08-01

    Mosquitoes (Diptera: Culicidae) are vectors of important pathogens and parasites, including malaria, dengue, chikungunya, Japanese encephalitis, lymphatic filariasis and Zika virus. The application of synthetic insecticides causes development of resistance, biological magnification of toxic substances through the food chain, and adverse effects on the environment and human health. In this scenario, eco-friendly control tools of mosquito vectors are a priority. Here single-step fabrication of silver nanoparticles (AgNP) using a cheap aqueous leaf extract of Zornia diphylla as reducing and capping agent pf Ag(+) ions has been carried out. Biosynthesized AgNP were characterized by UV-visible spectrophotometry, Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy-dispersive spectroscopy (EDX) and X-ray diffraction analysis (XRD). The acute toxicity of Z. diphylla leaf extract and biosynthesized AgNP was evaluated against larvae of the malaria vector Anopheles subpictus, the dengue vector Aedes albopictus and the Japanese encephalitis vector Culex tritaeniorhynchus. Both the Z. diphylla leaf extract and Ag NP showed dose dependent larvicidal effect against all tested mosquito species. Compared to the leaf aqueous extract, biosynthesized Ag NP showed higher toxicity against An. subpictus, Ae. albopictus, and Cx. tritaeniorhynchus with LC50 values of 12.53, 13.42 and 14.61μg/ml, respectively. Biosynthesized Ag NP were found safer to non-target organisms Chironomus circumdatus, Anisops bouvieri and Gambusia affinis, with the respective LC50 values ranging from 613.11 to 6903.93μg/ml, if compared to target mosquitoes. Overall, our results highlight that Z. diphylla-fabricated Ag NP are a promising and eco-friendly tool against larval populations of mosquito vectors of medical and veterinary importance, with negligible toxicity against other non-target organisms. PMID:27318605

  6. Advection around ventilated U-shaped burrows: A model study

    Science.gov (United States)

    Brand, Andreas; Lewandowski, JöRg; Hamann, Enrico; Nützmann, Gunnar

    2013-05-01

    Advective transport in the porous matrix of sediments surrounding burrows formed by fauna such as Chironomus plumosus has been generally neglected. A positron emission tomography study recently revealed that the pumping activity of the midge larvae can indeed induce fluid flow in the sediment. We present a numerical model study which explores the conditions at which advective transport in the sediment becomes relevant. A 0.15 m deep U-shaped burrow with a diameter of 0.002 m within the sediment was represented in a 3-D domain. Fluid flow in the burrow was calculated using the Navier-Stokes equation for incompressible laminar flow in the burrow, and flow in the sediment was described by Darcy's law. Nonreactive and reactive transport scenarios were simulated considering diffusion and advection. The pumping activity of the model larva results in considerable advective flow in the sediment at reasonable high permeabilities with flow velocities of up to 7.0 × 10-6 m s-1 close to the larva for a permeability of 3 × 10-12 m2. At permeabilities below 7 × 10-13 m2 advection is negligible compared to diffusion. Reactive transport simulations using first-order kinetics for oxygen revealed that advective flux into the sediment downstream of the pumping larva enhances sedimentary uptake, while the advective flux into the burrow upstream of the larvae inhibits diffusive sedimentary uptake. Despite the fact that both effects cancel each other with respect to total solute uptake, the advection-induced asymmetry in concentration distribution can lead to a heterogeneous solute and redox distribution in the sediment relevant to complex reaction networks.

  7. Microscale ecotoxicity testing of Moselle river watershed (Lorraine Province, France sediments

    Directory of Open Access Journals (Sweden)

    Jean François Férard

    2015-06-01

    Full Text Available The ecotoxic potential of seven Moselle river watershed sediments was assessed with a battery of bioassays comprised of rapid phototrophic [LuminoTox solid phase (L-SPA and elutriate (L-ELU assays] and bacterial [Microtox solid phase assay (M-SPA] exposure tests, as well as with two micro-invertebrate solid phase tests conducted with Hydra attenuata (lethal and sublethal effects solid phase assay, HL-SPA and HSL-SPA and Chironomus riparius. Measured effects of sediments and their elutriates were varied and reflected responses that were ecotoxicity test-, endpoint- and site-dependent, suggesting some degree of risk toward benthic and water column organisms, respectively, at specific sites. Correlation analysis demonstrated that L-SPA and M-SPA ecotoxicity responses were significantly linked with the Hydra HSL-SPA assay, indicating their ability to predict ecotoxicity towards an invertebrate taxonomic group representing secondary consumers. While the L-SPA and M-SPA assays hold promise as rapid screens for sediment ecotoxicity, correlation analysis with grain size (L-SPA: r=-0.795, P=0.033; M-SPA: r=-0.73, P=0.07 points out that their responses can be influenced by the presence of fines (i.e., sediment particles ≤0.063 mm in size and that this information is essential to properly interpret ecotoxicity data generated with these assays. Finally, notable differences observed in trophic level sensitivities once again recall the importance of employing a test battery to adequately appraise the ecotoxicity of sediments.

  8. Succession of the ecosystems of the Aral Sea during its transition from oligohaline to polyhaline water body

    Science.gov (United States)

    Mirabdullayev, Iskandar M.; Joldasova, Iliya M.; Mustafaeva, Zuri A.; Kazakhbaev, Saparbay; Lyubimova, Svetlana A.; Tashmukhamedov, Bekdjan A.

    2004-06-01

    During 22 field trips from 1990 to 2002 (mainly the western basin of the Large Aral) data on salinity, phytoplankton, zooplankton, zoobenthos and fish fauna have been collected. In 2002, the salinity of the western basin reached 75 ppt, while that in the eastern basin, 150 ppt. In 1999-2002, 159 species of planktonic algae have been recorded. This is approximately twice as low as recorded before. The diversity of Cyanophyta, Pyrrhophyta and Chlorophyta in particular has dropped in the past few years. As before, currently Bacillariophyta is the most diverse plankton. However, the composition of dominants has changed. Once previously dominant species, Actinocyclus ehrenbergii, vanished from the plankton of the Aral Sea and was replaced by such diatoms as Amphora coffeaformis, A. coffeaformis var. acutiuscula and Synedra tabulata var. parva. Since 1970s, a gradual decrease in the diversity of zooplankton has been taking place. Since 1997, the formerly dominant Calanipeda aquaedulcis vanished, which apparently was the reason for the emergence of Moina salina and Artemia parthenogenetica. Since 2000, artemia has been dominant in the plankton of the Aral Sea, constituting 99% of the zooplankton biomass. In the 1970-1980s, a rapid decrease in the biodiversity of the zoobenthos was observed. In the 1990s, most aboriginal and introduced species became extinct. Currently, the bivalve mollusk Syndosmya segmentum, the ostracod Cyprideis torosa and larvae of the dipteran Chironomus salinarius can still be recorded in the western basin. In the eastern basin no benthos is observed. By 1998, in the Large Aral, only five fish species survived: baltic herring Clupea harengus membras, flounder Platichthys flesus luscus, atherine Atherina boyeri caspia and bullheads Neogobius fluviatilis and Potamoschistus caucasicus. Since 2002, only flounder and atherina have been recorded in the western basin of the Large Aral. No fish have been recorded in the eastern part of the Aral Sea in 2002

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

    Science.gov (United States)

    Brock, T C M; Bas, D A; Belgers, J D M; Bibbe, L; Boerwinkel, M-C; Crum, S J H; Diepens, N J; Kraak, M H S; Vonk, J A; Roessink, I

    2016-08-01

    Sediment ecotoxicity studies were conducted with lufenuron to (i) complement the results of a water-spiked mesocosm experiment with this lipophilic benzoylurea insecticide, (ii) to explore the predictive value of laboratory single-species tests for population and community-level responses of benthic macroinvertebrates, and (iii) to calibrate the tier-1 effect assessment procedure for sediment organisms. For this purpose the concentration-response relationships for macroinvertebrates between sediment-spiked microcosms and those of 28-d sediment-spiked single-species toxicity tests with Chironomus riparius, Hyalella azteca and Lumbriculus variegatus were compared. Lufenuron persisted in the sediment of the microcosms. On average, 87.7% of the initial lufenuron concentration could still be detected in the sediment after 12 weeks. Overall, benthic insects and crustaceans showed treatment-related declines and oligochaetes treatment-related increases. The lowest population-level NOEC in the microcosms was 0.79μg lufenuron/g organic carbon in dry sediment (μg a.s./g OC) for Tanytarsini, Chironomini and Dero sp. Multivariate analysis of the responses of benthic macroinvertebrates revealed a community-level NOEC of 0.79μg a.s./g OC. The treatment-related responses observed in the microcosms are in accordance with the results of the 28-d laboratory toxicity tests. These tests showed that the insect C. riparius and the crustacean H. azteca were approximately two orders of magnitude more sensitive than the oligochaete L. variegatus. In our laboratory tests, using field-collected sediment, the lowest 28-d EC10 (0.49μg a.s./g OC) was observed for C. riparius (endpoint survival), while for the standard OECD test with this species, using artificial sediment, a NOEC of 2.35μg a.s./g OC (endpoint emergence) is reported. In this particular case, the sediment tier-1 effect assessment using the chronic EC10 (field-collected sediment) or chronic NOEC (artificial sediment) of C

  10. Profundal benthic invertebrates in an oligotrophic tropical lake: different strategies for coping with anoxia

    Directory of Open Access Journals (Sweden)

    María del Carmen Hernández

    2014-05-01

    Full Text Available The deep benthic communities of tropical lakes are poorly understood with respect to their composition, abundance, biomass and regulatory factors. Whereas the hypolimnia of temperate oligotrophic lakes remain oxygenated, the higher temperatures in tropical lakes frequently lead to the rapid development of hypolimnetic anoxia independent of trophic status. The deep benthic communities of tropical lakes must therefore develop strategies to respond to anoxic conditions. The dynamics of the deep benthic community of Lake Alchichica were studied over 15 months. We hypothesized that the sedimentation of the winter diatom bloom constitutes an input of high-quality food that contributes to the establishment and development of the deep benthic community. However, the remineralization of this organic matter leads to the prompt development of hypolimnetic anoxia, thus limiting the establishment and/or persistence of the deep benthic community. In contrast with the diverse littoral benthic community (50 taxa in Lake Alchichica, only two species constitute its deep benthic community, the ostracod Candona cf. patzcuaro and the chironomid Chironomus cf. austini, which combined exhibit a low density (1197±1976 ind m-2 and biomass (16.13±30.81 mg C m-2. C. patzcuaro is dominant and is present throughout the year, whereas Ch. austini is recorded only when the bottom water of the lake is oxygenated. A comparison with the analogous but temperate Lake Mergozzo in Italy illustrates the role that anoxia plays in tropical lakes by diminishing not only taxonomic richness (13 versus 2 spp. in temperate versus tropical lakes, respectively but also abundance (1145 versus 287 ind m-2, respectively. C. patzcuaro is found throughout the annual cycle of the lake’s profundal zone, entering into diapause during the anoxic period and recovering as soon as the profundal zone reoxygenates. Ch. austini has adjusted its life cycle to use the habitat and available resources while

  11. The chronic toxicity of molybdate to freshwater organisms. I. Generating reliable effects data

    Energy Technology Data Exchange (ETDEWEB)

    De Schamphelaere, K.A.C., E-mail: karel.deschamphelaere@Ugent.be [Laboratory of Environmental Toxicology and Aquatic Ecology, Faculty of Bioscience Engineering, Ghent University (Belgium); Stubblefield, W. [Oregon State University, Department of Environmental and Molecular Toxicology, 421 Weniger Hall, Corvallis, OR 97331 (United States); Rodriguez, P. [Centro de Investigacion Minera y Metalurgica (CIMM), Santiago (Chile); Vleminckx, K. [Department for Molecular Biomedical Research, Ghent University (Belgium); Janssen, C.R. [Laboratory of Environmental Toxicology and Aquatic Ecology, Faculty of Bioscience Engineering, Ghent University (Belgium)

    2010-10-15

    The European Union regulation on Registration, Evaluation, Authorization and Restriction of Chemical substances (REACH) (EC, 2006) requires the characterization of the chronic toxicity of many chemicals in the aquatic environment, including molybdate (MoO{sub 4}{sup 2-}). Our literature review on the ecotoxicity of molybdate revealed that a limited amount of reliable chronic no observed effect concentrations (NOECs) for the derivation of a predicted no-effect concentration (PNEC) existed. This paper presents the results of additional ecotoxicity experiments that were conducted in order to fulfill the requirements for the derivation of a PNEC by means of the scientifically most robust species sensitivity distribution (SSD) approach (also called the statistical extrapolation approach). Ten test species were chronically exposed to molybdate (added as sodium molybdate dihydrate, Na{sub 2}MoO{sub 4}.2H{sub 2}O) according to internationally accepted standard testing guidelines or equivalent. The 10% effective concentrations (EC10, expressed as measured dissolved molybdenum) for the most sensitive endpoint per species were 62.8-105.6 (mg Mo)/L for Daphnia magna (21 day-reproduction), 78.2 (mg Mo)/L for Ceriodaphnia dubia (7 day-reproduction), 61.2-366.2 (mg Mo)/L for the green alga Pseudokirchneriella subcapitata (72 h-growth rate), 193.6 (mg Mo)/L for the rotifer Brachionus calyciflorus (48 h-population growth rate), 121.4 (mg Mo)/L for the midge Chironomus riparius (14 day-growth), 211.3 (mg Mo)/L for the snail Lymnaea stagnalis (28 day-growth rate), 115.9 (mg Mo)/L for the frog Xenopus laevis (4 day-larval development), 241.5 (mg Mo)/L for the higher plant Lemna minor (7 day-growth rate), 39.3 (mg Mo)/L for the fathead minnow Pimephales promelas (34 day-dry weight/biomass), and 43.2 (mg Mo)/L for the rainbow trout Oncorhynchus mykiss (78 day-biomass). These effect concentrations are in line with the few reliable data currently available in the open literature. The data

  12. The chronic toxicity of molybdate to freshwater organisms. I. Generating reliable effects data.

    Science.gov (United States)

    De Schamphelaere, K A C; Stubblefield, W; Rodriguez, P; Vleminckx, K; Janssen, C R

    2010-10-15

    The European Union regulation on Registration, Evaluation, Authorization and Restriction of Chemical substances (REACH) (EC, 2006) requires the characterization of the chronic toxicity of many chemicals in the aquatic environment, including molybdate (MoO(4)(2-)). Our literature review on the ecotoxicity of molybdate revealed that a limited amount of reliable chronic no observed effect concentrations (NOECs) for the derivation of a predicted no-effect concentration (PNEC) existed. This paper presents the results of additional ecotoxicity experiments that were conducted in order to fulfill the requirements for the derivation of a PNEC by means of the scientifically most robust species sensitivity distribution (SSD) approach (also called the statistical extrapolation approach). Ten test species were chronically exposed to molybdate (added as sodium molybdate dihydrate, Na(2)MoO(4)·2H(2)O) according to internationally accepted standard testing guidelines or equivalent. The 10% effective concentrations (EC10, expressed as measured dissolved molybdenum) for the most sensitive endpoint per species were 62.8-105.6 (mg Mo)/L for Daphnia magna (21day-reproduction), 78.2 (mg Mo)/L for Ceriodaphnia dubia (7day-reproduction), 61.2-366.2 (mg Mo)/L for the green alga Pseudokirchneriella subcapitata (72h-growth rate), 193.6 (mg Mo)/L for the rotifer Brachionus calyciflorus (48h-population growth rate), 121.4 (mg Mo)/L for the midge Chironomus riparius (14day-growth), 211.3 (mg Mo)/L for the snail Lymnaea stagnalis (28day-growth rate), 115.9 (mg Mo)/L for the frog Xenopus laevis (4day-larval development), 241.5 (mg Mo)/L for the higher plant Lemna minor (7day-growth rate), 39.3 (mg Mo)/L for the fathead minnow Pimephales promelas (34day-dry weight/biomass), and 43.2 (mg Mo)/L for the rainbow trout Oncorhynchus mykiss (78day-biomass). These effect concentrations are in line with the few reliable data currently available in the open literature. The data presented in this study can

  13. Weight-of-evidence approach in assessment of ecotoxicological risks of acid sulphate soils in the Baltic Sea river estuaries

    Energy Technology Data Exchange (ETDEWEB)

    Wallin, Jaana, E-mail: jaana.wallin@jyu.fi [Finnish Environment Institute SYKE, Survontie 9 A, FI-40500 Jyväskylä (Finland); Karjalainen, Anna K. [Finnish Environment Institute SYKE, Survontie 9 A, FI-40500 Jyväskylä (Finland); Schultz, Eija [Finnish Environment Institute SYKE, Hakuninmaantie 6, FI-00430 Helsinki (Finland); Järvistö, Johanna; Leppänen, Matti; Vuori, Kari-Matti [Finnish Environment Institute SYKE, Survontie 9 A, FI-40500 Jyväskylä (Finland)

    2015-03-01

    Acidity and leaching of metals from acid sulphate soils (ASSs) impair the water quality of receiving surface waters. The largest ASS areas in Europe are found in the coasts of the northern Baltic Sea. We used weight-of-evidence (WoE) approach to assess potential risks in 14 estuary sites affected by ASS in the Gulf of Finland, northern Baltic Sea. The assessment was based on exposure and effect profiles utilizing sediment and water metal concentrations and concurrent pH variation, sediment toxicity tests using the luminescent bacterium Vibrio fischeri and the midge Chironomus riparius, and the ecological status of benthic macroinvertebrate communities. Sediment metal concentrations were compared to national sediment quality criteria/guidelines, and water metal concentrations to environmental quality standards (EQSs). Hazard quotients (HQs) were established for maximum aluminium, cadmium and zinc concentrations at low pH based on applicable US EPA toxicity database. Sediment metal concentrations were clearly elevated in most of the studied estuaries. The EQS of cadmium (0.1 μg/l) was exceeded in 3 estuaries out of 14. The pH-minima were below the national threshold value (5.5) between good and satisfactory water quality in 10 estuaries. V. fischeri bioluminescence indicated toxicity of the sediments but toxic response was not observed in the C. riparius emergence test. Benthic invertebrate communities were deteriorated in 6 out of 14 sites based on the benthic invertebrate quality index. The overall ecotoxicological risk was assessed as low in five, moderate in three and high in five of the estuary sites. The risk assessment utilizing the WoE approach indicated that harmful effects of ASSs are likely to occur in the Baltic Sea river estuaries located at the ASS hotspot area. - Highlights: • Acid sulphate soils release high amounts of metals and acidity. • Metals and acidity are transported to estuary sites. • Acid sulphate soils impair the ecological status

  14. Influence of benthic macro-invertebrate bioturbation on the biogeochemical behaviour of uranium within freshwater sediments

    International Nuclear Information System (INIS)

    In freshwater ecosystems, sediments act as an accumulation compartment for metallic pollutants as uranium. Secondary, there can also represent endogenous sources of contamination by resuspension (e.g. flood, bioturbation) or changes of metal speciation that acts upon their bioavailability. Indeed, metallic compounds can be transformed in more or less toxic or inert compounds through physico-chemical (e.g. pH, redox conditions, ionic force) and microbiological variations. These conditions are themselves under the effects of benthic macro-invertebrate activities via bioturbation processes. The main objective of this PhD was to determinate the influence of two benthic macro-invertebrate species (Chironomus riparius and Tubifex tubifex) on the distribution and the transfers of uranium within freshwater sediments. To reach this goal, laboratory experiments were performed in order to (i) assess the effects of uranium on benthic macro-invertebrates, more particularly on their bioturbation activity, (ii) determine the influence of these organisms on uranium behaviour through high resolution physico-chemical measurements (e.g. oxygen optodes, DET gel probes), and (iii) estimate the consequences of these interactions on pelagic organisms via genotoxicity measurements (micronuclei assay and molecular bio-markers analysis on Xenopus laevis). The results demonstrate that bioturbation intensity of macro-invertebrates can be affected in uranium-contaminated sediments, but the two species studied in this work show a relative tolerance. For high uranium concentrations (>100 times the geochemical background level), corresponding however to realistic concentrations in highly contaminated sites, T. tubifex worms are able to maintain a sufficient bioturbation activity that induces a high remobilization of uranium initially associated with sediments to the overlying water (factor 2 to 10). That represents therefore a potential risk for the remaining aquatic biocenose. However, by

  15. Examining waterborne and dietborne routes of exposure and their contribution to biological response patterns in fathead minnow (Pimephales promelas)

    Energy Technology Data Exchange (ETDEWEB)

    Rozon-Ramilo, Lisa D., E-mail: lisa.ramilo@usask.ca [University of Saskatchewan, Toxicology Centre, 44 Campus Drive, Saskatoon, Saskatchewan S7N 5B3 (Canada); Dube, Monique G., E-mail: moniqe.dube@usask.ca [University of Saskatchewan, School of Environment and Sustainability, 117 Science Place, Saskatoon, Saskatchewan S7N 2X8 (Canada); Squires, Allison J., E-mail: allison.squires@usask.ca [University of Saskatchewan, Toxicology Centre, 44 Campus Drive, Saskatoon, Saskatchewan S7N 5B3 (Canada); Niyogi, Som, E-mail: som.niyogi@usask.ca [University of Saskatchewan, Department of Biology, 112 Science Place, Saskatoon, Saskatchewan S7N 5E2 (Canada)

    2011-10-15

    Highlights: Objective (i) was achieved by isolating each route of exposure (diet, water and the combination of the two) and comparing it to a control. The metal mining effluent studied encompassed several different effluent types including: mine water, mill facility, tailing impoundment, treatment pond, treatment facility, seepage and surface drainage effluent. Experiment 1 examined exposure pathways by isolating effluent exposure through the diet, water or the combination of the two. Experiment 2 examined whether differences in Fathead minnow responses occurred when fish were fed a live or frozen (dead) diet of chironomids. Multiple trophic levels (consumers and carnivores) were placed in each artificial stream simultaneously. Primary route of exposure to Fathead minnow when held in control water and fed effluent-exposed chironomid larvae. - Abstract: The objectives of the current study were: (i) to gain a better understanding of the relative importance of water and diet as routes of exposure causing toxicity in fathead minnow (FHM) exposed to metal mining effluents (MME) using a full factorial water/food experimental design (Experiment 1), and (ii) to assess differences in the effects of food quality on toxicity by comparing FHM fed both a live and frozen diet of Chironomus dilutus (Experiment 2). The results showed significant increases in general water quality parameters (e.g., hardness, conductivity) and various metals in the effluent treatment waters compared to control waters, with maximum increase seen in the multi-trophic streams. Metals accumulation (Rb, Al, Se, Sr, Tl, Ce, Co, Cu, Pb) effects of both waterborne and multi-trophic exposures were significant in one or more fathead minnow tissue type (muscle, gonads, liver, larvae) relative to those in the control systems. Condition factor and liver somatic index (LSI) of FHM were also significantly affected in both exposures by one or both routes of exposure (water and/or diet). In addition, cumulative

  16. Toxicity of environmental chemicals and their mixtures to selected aquatic organisms. Behaviour, development and biochemistry; Toxizitaet von Umweltchemikalien und deren Mischungen auf ausgewaehlte aquatische Organismen. Verhalten, Entwicklung und Biochemie

    Energy Technology Data Exchange (ETDEWEB)

    Kienle, Cornelia

    2009-04-28

    In this work, the effects of various single substances (pesticides and metals) as well as binary mixtures of them on zebrafish (Danio rerio) embryos and larvae were assessed on biochemical, developmental, and organism levels. The influence of oxygen depletion on the toxicity of substances was included as an additional interacting factor. To analyse complex interactions, the predator-prey behaviour between zebrafish and chironomid larvae (Chironomus riparius) was investigated. Another aspect of this work were studies on complex mixtures of hydrocarbons such as the water accommodated fraction of crude oil, and their effects on the behaviour of marine amphipods (Corophium volutator), as well as semi-field experiments with freshwater amphipods (Gammarus pulex). My investigations showed that effects of various substances in environmentally relevant concentration ranges are exerted on different levels of biological organisation, both in amphipods and fish. It could be shown that abiotic parameters modify the effects of pollutants. When investigating mixtures of substances with similar or different modes of action, additivity occurred in the majority of cases which usually were consistent for all investigated parameters (enzyme activity, locomotor activity, developmental impairment, mortality). Effects of the neurotoxic insecticide chlorpyrifos on the interactions between fish and chironomids could be detected in environmentally relevant concentration ranges. The effects of the water accommodated fraction of crude oil which represents a great risk for aquatic organisms in costal habitats were displayed by alterations in the behaviour of the marine amphipod Corophium volutator. For a continuous monitoring of water quality in monitoring stations, the resident amphipod Gammarus pulex proved to be a suitable and relevant test organism, as it responds sensitive to complex mixtures of pollutants in surface waters. In summary, behavioural parameters proved to be integrative

  17. Haemoglobin, a new major allergen of Anisakis simplex.

    Science.gov (United States)

    González-Fernández, Juan; Daschner, Alvaro; Nieuwenhuizen, Natalie E; Lopata, Andreas L; Frutos, Consolación De; Valls, Ana; Cuéllar, Carmen

    2015-05-01

    Gastro-allergic anisakiasis and Anisakis sensitisation associated chronic urticaria are diseases which differ in their IgE and IgG4 responses against both crude extract and specific allergens. Anisakis and Ascaris are closely related nematodes that usually cause problems with specificity in immunodiagnostics. In this study we measured IgE and IgG4 antibodies against Anisakis simplex sensu lato (s. l.) and Ascaris suum haemoglobins in sera of 21 gastro-allergic anisakiasis and 23 chronic urticaria patients. We used a capture ELISA with the anti-Anisakis haemoglobin monoclonal antibody 4E8g, which also recognises Ascaris haemoglobin. In addition, we determined specific IgE and IgG4 to both nematodes by indirect ELISA and immunoblotting. Anti-A. simplex s. l. haemoglobin IgE and IgG4 levels were higher in gastro-allergic anisakiasis than in chronic urticaria patients (P=0.002 and 0.026, respectively). Surprisingly, no patient had detectable IgE levels against A. suum haemoglobin. Finally, we carried out an in silico study of the B-cell epitopes of both haemoglobin molecules. Five epitopes were predicted in Anisakis pegreffii and four in A. suum haemoglobin. The epitope propensity values of Anisakis haemoglobin in the equivalent IgE binding region of the allergenic haemoglobin Chi t 1 from Chironomus thummi, were higher those of the Ascaris haemoglobin. In conclusion, we describe A. simplex haemoglobin as a new major allergen (Ani s 13), being recognised by a large number (64.3%) of sensitised patients and up to 80.9% in patients with gastro-allergic anisakiasis. The presence of a specific epitope and the different values of epitope propensity between Anisakis and Ascaris haemoglobin could explain the lack of cross-reactivity between the two molecules. The absence of IgE reactivity to Ascaris haemoglobin in Anisakis patients makes Anisakis haemoglobin (Ani s 13) a potential candidate for developing more specific diagnosis tools. PMID:25683373

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

    Science.gov (United States)

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

    2013-01-01

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

  19. Benthic invertebrate bioassays with toxic sediment and pore water

    Science.gov (United States)

    Giesy, John P.; Rosiu, Cornell J.; Graney, Robert L.; Henry, Mary G.

    1990-01-01

    The relative sensitivities of bioassays to determine the toxicity of sediments were investigated and three methods of making the sample dilutions required to generate dose-response relationships were compared. The assays studied were: (a) Microtox®, a 15-min assay ofPhotobacterium phosphoreum bioluminescence inhibition by pore water; (b) 48-h Daphnia magnalethality test in pore water; (c) 10-d subchronic assay of lethality to and reduction of weight gain by Chironomus tentans performed in either whole sediment or pore water; (d) 168-h acute lethality assay of Hexagenia limbata in either whole sediment or pore water. The three methods of diluting sediments were: (a) extracting pore water from the toxic location and dilution with pore water from the control station; (b) diluting whole sediment from the toxic location with control whole sediment from a reference location, then extracting pore water; and (c) diluting toxic, whole sediment with whole sediment from a reference location, then using the whole sediment in bioassays. Based on lethality, H. limbata was the most sensitive organism to the toxicity of Detroit River sediment. Lethality of D. magna in pore water was similar to that of H. limbata in whole sediment and can be used to predict effects of whole sediment toxicity to H. limbata. The concentration required to cause a 50% reduction in C. tentans growth (10-d EC50) was approximately that which caused 50% lethality of D. magna (48-h LC50) and was similar to the toxicity that restricts benthic invertebrate colonization of contaminated sediments. While the three dilution techniques gave similar results with some assays, they gave very different results in other assays. The dose-response relationships determined by the three dilution techniques would be expected to vary with sediment, toxicant and bioassay type, and the dose-response relationship derived from each technique needs to be interpreted accordingly.

  20. Weight-of-evidence approach in assessment of ecotoxicological risks of acid sulphate soils in the Baltic Sea river estuaries

    International Nuclear Information System (INIS)

    Acidity and leaching of metals from acid sulphate soils (ASSs) impair the water quality of receiving surface waters. The largest ASS areas in Europe are found in the coasts of the northern Baltic Sea. We used weight-of-evidence (WoE) approach to assess potential risks in 14 estuary sites affected by ASS in the Gulf of Finland, northern Baltic Sea. The assessment was based on exposure and effect profiles utilizing sediment and water metal concentrations and concurrent pH variation, sediment toxicity tests using the luminescent bacterium Vibrio fischeri and the midge Chironomus riparius, and the ecological status of benthic macroinvertebrate communities. Sediment metal concentrations were compared to national sediment quality criteria/guidelines, and water metal concentrations to environmental quality standards (EQSs). Hazard quotients (HQs) were established for maximum aluminium, cadmium and zinc concentrations at low pH based on applicable US EPA toxicity database. Sediment metal concentrations were clearly elevated in most of the studied estuaries. The EQS of cadmium (0.1 μg/l) was exceeded in 3 estuaries out of 14. The pH-minima were below the national threshold value (5.5) between good and satisfactory water quality in 10 estuaries. V. fischeri bioluminescence indicated toxicity of the sediments but toxic response was not observed in the C. riparius emergence test. Benthic invertebrate communities were deteriorated in 6 out of 14 sites based on the benthic invertebrate quality index. The overall ecotoxicological risk was assessed as low in five, moderate in three and high in five of the estuary sites. The risk assessment utilizing the WoE approach indicated that harmful effects of ASSs are likely to occur in the Baltic Sea river estuaries located at the ASS hotspot area. - Highlights: • Acid sulphate soils release high amounts of metals and acidity. • Metals and acidity are transported to estuary sites. • Acid sulphate soils impair the ecological status

  1. Toxicity of solid residues resulting from wastewater treatment with nanomaterials.

    Science.gov (United States)

    Nogueira, Verónica; Lopes, Isabel; Rocha-Santos, Teresa; Gonçalves, Fernando; Pereira, Ruth

    2015-08-01

    Nanomaterials (NMs) are widely recommended for wastewater treatments due to their unique properties. Several studies report the different advantages of nanotechnology in the remediation of wastewaters, but limited research has been directed toward the fate and potential impacts of the solid residues (SRs) produced after the application of such technologies. The present work aimed at investigating the ecotoxicity of SRs resulting from the treatment of three effluents (OOMW, kraft pulp mill, and mining drainage) with two NMs (TiO2 and Fe2O3). The invertebrate Chironomus riparius was selected as test organism and exposed to the residues. The effect on percentage of survival and growth was assessed. Results showed that the SRs from the treatments nano-TiO2(1.0gL(-1))/H2O2(0.5M) and nano-Fe2O3(1.0gL(-1))/H2O2(1.0M) from OOMW and nano-Fe2O3(0.75gL(-1))/H2O2(0.01M) from kraft pulp mill effluent exhibited lethal toxicity to C. riparius. Only the exposure to SRs resulting from the treatment with nano-Fe2O3(0.75gL(-1))/H2O2(0.01M) applied to the kraft pulp mill effluent significantly affected the growth rate based on the head capsule width. In terms of growth rate, based on the body length, it decreased significantly after exposure to the SRs from the treatments nano-TiO2 (1.0gL(-1)) and nano-Fe2O3(0.75gL(-1))/H2O2(0.01M) of kraft paper mill effluent and nano-Fe2O3(1.0gL(-1))/H2O2(1.0M) of OOMW. According to our study the SRs can promote negative effects on C. riparius. However, the effects are dependent on the type of effluent treated as well as on the organic and inorganic compounds attached to the NMs. PMID:26057932

  2. The role of benthic macrofauna on nitrogen cycling in eutrophic lake sediment

    Energy Technology Data Exchange (ETDEWEB)

    Svensson, J.M.

    1998-12-01

    This thesis concerns the role of sediment-living macrobenthos in the cycling of nitrogen species and nitrogen transformation in eutrophic freshwater sediments. In my thesis I have, employing {sup 15}N-isotope techniques in laboratory experiments, shown the importance of infaunal chironomid larvae and oligochaetes on denitrification in eutrophic lake sediments. Investigated benthic organisms not only expand the sediment surface with their permanent or non-permanent burrow constructions, they also transport water through the burrows continuously. This behaviour of intermittent water-pumping activity, provides the burrows with oxygen, and in addition, mediates the supply of nitrate to denitrifying zones. The highly dynamic oxygen climate within and narrow oxic zones around burrows, due to their radial geometry, provides a very short diffusion path for nitrate into surrounding anoxic zones. In my studies rates of denitrification were enhanced c. 3 to 6-fold by the influence of chironomids (Chironomus plumosus) and c. 2-fold by the influence of oligochaetes at comparable biomass. The difference in degree of stimulation is explained by species-specific habitat exploitation which could also be observed between different tube-dwelling species of chironomids. Besides chironomid biomass, the degree of enhancement of denitrification by chironomids was dependent on nitrate concentration in the overlying water, and water temperature. Nitrification was also seen to be stimulated by the infaunal macrobenthos but to a lesser degree than denitrification. It is suggested that bioturbated eutrophic sediment, under predominantly oxic bottom water conditions may act more pronouncedly as a sink for inorganic nitrogen relative to non-bioturbated sediment, and that bioturbated sediment above all, may be an important factor contributing to lowered transport of nitrogen to the coast. In order to sustain high nitrogen removal capacity in wetlands, ponds and lakes, it is further suggested

  3. Examining waterborne and dietborne routes of exposure and their contribution to biological response patterns in fathead minnow (Pimephales promelas)

    International Nuclear Information System (INIS)

    Highlights: Objective (i) was achieved by isolating each route of exposure (diet, water and the combination of the two) and comparing it to a control. The metal mining effluent studied encompassed several different effluent types including: mine water, mill facility, tailing impoundment, treatment pond, treatment facility, seepage and surface drainage effluent. Experiment 1 examined exposure pathways by isolating effluent exposure through the diet, water or the combination of the two. Experiment 2 examined whether differences in Fathead minnow responses occurred when fish were fed a live or frozen (dead) diet of chironomids. Multiple trophic levels (consumers and carnivores) were placed in each artificial stream simultaneously. Primary route of exposure to Fathead minnow when held in control water and fed effluent-exposed chironomid larvae. - Abstract: The objectives of the current study were: (i) to gain a better understanding of the relative importance of water and diet as routes of exposure causing toxicity in fathead minnow (FHM) exposed to metal mining effluents (MME) using a full factorial water/food experimental design (Experiment 1), and (ii) to assess differences in the effects of food quality on toxicity by comparing FHM fed both a live and frozen diet of Chironomus dilutus (Experiment 2). The results showed significant increases in general water quality parameters (e.g., hardness, conductivity) and various metals in the effluent treatment waters compared to control waters, with maximum increase seen in the multi-trophic streams. Metals accumulation (Rb, Al, Se, Sr, Tl, Ce, Co, Cu, Pb) effects of both waterborne and multi-trophic exposures were significant in one or more fathead minnow tissue type (muscle, gonads, liver, larvae) relative to those in the control systems. Condition factor and liver somatic index (LSI) of FHM were also significantly affected in both exposures by one or both routes of exposure (water and/or diet). In addition, cumulative

  4. Thesis Abstract Morphological and phylogeographic analysis of Brazilian tortoises (Testudinidae).

    Science.gov (United States)

    Silva, T L; Venancio, L P R; Bonini-Domingos, C R

    2015-12-29

    The discriminative potentials of biogeography, vocalization, morphology, cytogenetics, hemoglobin, and molecular profiling of cytochrome b as taxonomic techniques for differentiating Brazilian tortoises were evaluated in this study. In Brazil, two species of tortoises are described, Chelonoidis carbonarius and Chelonoidis denticulatus. However, in the present study, some animals that were initially recognized based on morphological characters and coloring did not correspond to the typical pattern of C. carbonarius; these animals were classified as morphotypes 1 and 2. It was proposed that these morphotypes are differentiated species, and they should not be considered as a single taxonomic unit with C. carbonarius. Tortoises analyzed were provided by the National Institute for Amazonian Research (INPA); the Emilio Goeldi Museum, PA; municipal zoos in São José do Rio Preto, SP, and Araçatuba, SP; and the Reginaldo Uvo Leone breeding farm for Wild and Exotic Animals, Tabapuã, SP. Based on the data obtained using biogeographic evaluation of specimens in the literature, it was found that C. carbonarius is distributed in the Northeast Region of Brazil, and no animal of this pattern was observed in the investigated collections. On the other hand, C. denticulatus is found in all the states of the Legal Amazonia. In addition, isolated individual records of this species exist in the Atlantic Forest in Espírito Santo and Rio de Janeiro and in the Midwest Region composed of the states of Goiás, Mato Grosso, and Mato Grosso do Sul. In the Northeast Region, C. denticulatus occurs in the State of Bahia. Morphotype 1 has a wider geographical distribution than C. carbonarius, possibly because of several distribution reports associated with C. carbonarius, indicating erroneous association of morphotype 1 as a single taxonomic unit with C. carbonarius. Morphotype 2 is found only in the states of Pará, Maranhão, and Piauí. These biogeographic data indicate that the

  5. Quantitative analysis of cholinesterase from Daphnia magna by indirect and non-competitive enzyme-linked immunosorbent assay%大型溞胆碱酯酶间接非竞争酶联免疫吸附定量分析法的建立

    Institute of Scientific and Technical Information of China (English)

    刘洪翠; 杨艳霞; 李少南

    2012-01-01

    用达到电泳纯的大型溞(Daphnia magna)胆碱酯酶(cholinesterase,ChE)免疫BALB/c小鼠,得到效价达1∶8000的鼠抗大型溞ChE多克隆抗血清;通过优化抗原抗体反应条件,建立定量分析大型溞ChE含量的间接非竞争酶联免疫吸附法(indirect and non-competitive enzyme-linked immunosorbent assay).结果表明:此方法检测灵敏度为24 ng·mL-1;经免疫交叉反应鉴定,所获抗血清与5、10 μg·mL-1标准蛋白质和其他生物如花翅摇蚊、尖额溞、斑马鱼(脑、脑除外的整体)、家蚕、意大利蜜蜂、赤子爱胜蚯蚓、非洲爪蟾(蝌蚪)等来源的ChE交叉反应率分别为:<0.25%、<0.25%、2.13%、10.19%、3.88%、3.56%、2.81%、3.93%、5.00%和2.75%,具较高的特异性.说明用本试验得到的抗血清建立的间接非竞争酶联免疫吸附法可用于大型溞体内ChE含量的测定,以利于在农药暴露环境下大型溞体内ChE活性的精确检测.%Polyclonal anti-serum of cholinesteiase with dilution ratio of 1 :8 000 was obtained by immunizing BALB/c mice with purified cholinesterase (ChE) from Daphnia magna. An indirect and non-competitive enzyme-linked immunosorbent assay (ELISA), which used mice anti-Daphnia ChE as antibodies to react with the Daphnia ChE, was established to quantify immunoreactive content of ChE in D. magna. The minimal detection limit of the method was estimated to be 24 ng-mL"'. Specificity of anti-serum was high, with cross reaction of <0. 25%, <0. 25%, 2.13%, 10.19%, 3.88%, 3.56%, 2.81%, 3.93%, 5.00% and 2.75% towards non-ChE marker (5. 10 μg·mL-1), Chironomus kiinensis, Alona sp. , Brachydanio rerio (the brain, the whole body without brain), Bombyx mori, Apis mellifera L., Eisenia foetida , and tadpoles of Xenopus laevis, respectively. It is indicated that the established method can be used to quantify immunoreactive content of ChE in D. magna so as to measureme accurately in vivo activity of the ChE in pesticide

  6. Reconstruction of Holocene palaeoclimate and environment in the Khatanga region, Russian Arctic

    Science.gov (United States)

    Syrykh, Ludmila; Nazarova, Larisa

    2016-04-01

    environmental conditions in Quarternary Period and especially in Holocene (Smol et al., 2005; Nazarova et al., 2013). Main aim of our the research is to perform a high-resolution Holocene temperature reconstructions for Taymyr (the northern most region of Russian Arctic) using lake sediments from Chatanga region, and statistical chironomid-based inference models for estimation of mean July air temperature and water depth from lakes in north-eastern Russia. We performed a multy-proxy reconstruction of palaeoclimate and environment in the Holocene using a 132 cm sediment core covering 6 ka of sedimentation. Based of the chironomids analysis we performed a quantitative reconstruction of mean July air temperature in the Chatanga region (Taymyr Peninsula). Our investigation has shown that modern fauna is well represented along the whole sediment core. Dominating taxa along the core are cold stenotherms such as Chironomus anthracinus-type, Hydrobaenus lugubris-type and Tanytarsus lugens-type. Faunistic composition of lower part of the core (before 5 ka BP) is characteristic for a warmer conditions, which is in accordance with the earlier studies showing that mean summer temperatures may have been 2.5° to 5.0°C warmer than today in Taymyr peninsula between 9 and 4 ka BP. During the last 3500 years, our record suggests cooler conditions as elsewhere in the Russian arctic. This project was financed by DAAD "Mikhail Lomonosov Program"

  7. Dyes removal of textile wastewater onto surfactant modified zeolite from coal ash and evaluation of the toxic effects

    International Nuclear Information System (INIS)

    Zeolites synthesized from fly and bottom ashes and modified with hexadecyltrimethylammonium (HDTMA) were used as adsorbent to remove dyes - Solophenyl Navy (SN) and Solophenyl Turquoise (ST) and their hydrolysed forms Solophenyl Navy Hydrolysed (SNH) and Solophenyl Turquoise Hydrolysed (STH), from simulated textile wastewater. The HDTMA-modified fly zeolite (ZMF) and HDTMA-modified bottom zeolite (ZMB) were characterized by different techniques, as X-ray fluorescence spectrometry, X-ray diffraction and scanning electron microscopy, etc. The ZMF and ZMB presented negative charge probably due to the formation of a partial bilayer of HDTMA on exchangeable active sites on the external surface of unmodified zeolite. Initial dye concentration, contact time and equilibrium adsorption were evaluated. The adsorption kinetic for SN, ST, SNH and STH onto the zeolites followed the pseudo second-order model. The equilibrium time was 20 min for SN and ST and 30 min for SNH and STH, respectively. Langmuir, Freundlich and Temkin models were applied to describe the adsorption isotherms. Adsorption of the dyes were best described by the Langmuir model, with exception to SN/ZPM, SNH/ZPM and SNH/ZLM systems that followed Freundlich model. The maximum adsorption capacities were 3,64; 3,57; 2,91 e 4,93 for SN, ST, SNH e STH by ZLM, respectively and 0,235; 0,492; 1,26 e 1,86 by ZPM, in this order. The best performance for hydrolyzed dyes has been attributed to reduction of the size of dyes molecules during the hydrolysis process. Acute toxicity of the dyes to a different organism were evaluated by different test-organisms. Waterflea, Ceriodaphnia dubia showed EC50 value of 1,25; 54,5; 0,78 and 2,56 mgL-1 for SN, ST, SNH and STH, respectively. The plant Lemna minor showed EC50 values of 18,9; 69,4; 10,9 and 70,9 mgL-1 for SN, ST, SNH and STH, respectively. Midges larvae of Chironomus tepperi showed EC50 values of 119 and 440 mgL-1 for SN and ST, respectively. Regarding the adsorption

  8. Dyes removal of textile wastewater onto surfactant modified zeolite from coal ash and evaluation of the toxic effects; Remocao de corantes de efluente textil por zeolita de cinzas de carvao modificada por surfactante e avaliacao dos efeitos toxicos

    Energy Technology Data Exchange (ETDEWEB)

    Ferreira, Patricia Cunico

    2015-07-01

    Zeolites synthesized from fly and bottom ashes and modified with hexadecyltrimethylammonium (HDTMA) were used as adsorbent to remove dyes - Solophenyl Navy (SN) and Solophenyl Turquoise (ST) and their hydrolysed forms Solophenyl Navy Hydrolysed (SNH) and Solophenyl Turquoise Hydrolysed (STH), from simulated textile wastewater. The HDTMA-modified fly zeolite (ZMF) and HDTMA-modified bottom zeolite (ZMB) were characterized by different techniques, as X-ray fluorescence spectrometry, X-ray diffraction and scanning electron microscopy, etc. The ZMF and ZMB presented negative charge probably due to the formation of a partial bilayer of HDTMA on exchangeable active sites on the external surface of unmodified zeolite. Initial dye concentration, contact time and equilibrium adsorption were evaluated. The adsorption kinetic for SN, ST, SNH and STH onto the zeolites followed the pseudo second-order model. The equilibrium time was 20 min for SN and ST and 30 min for SNH and STH, respectively. Langmuir, Freundlich and Temkin models were applied to describe the adsorption isotherms. Adsorption of the dyes were best described by the Langmuir model, with exception to SN/ZPM, SNH/ZPM and SNH/ZLM systems that followed Freundlich model. The maximum adsorption capacities were 3,64; 3,57; 2,91 e 4,93 for SN, ST, SNH e STH by ZLM, respectively and 0,235; 0,492; 1,26 e 1,86 by ZPM, in this order. The best performance for hydrolyzed dyes has been attributed to reduction of the size of dyes molecules during the hydrolysis process. Acute toxicity of the dyes to a different organism were evaluated by different test-organisms. Waterflea, Ceriodaphnia dubia showed EC50 value of 1,25; 54,5; 0,78 and 2,56 mgL{sup -1} for SN, ST, SNH and STH, respectively. The plant Lemna minor showed EC50 values of 18,9; 69,4; 10,9 and 70,9 mgL{sup -1} for SN, ST, SNH and STH, respectively. Midges larvae of Chironomus tepperi showed EC50 values of 119 and 440 mgL{sup -1} for SN and ST, respectively. Regarding

  9. Seafloor mapping at Olkiluoto western coast of Finland

    Energy Technology Data Exchange (ETDEWEB)

    Ilmarinen, K.; Leinikki, J.; Oulasvirta, P. (Alleco Oy, Helsinki (Finland))

    2009-02-15

    the more variable bottom and the more exposed location compared to the corresponding transects 2 and 3, 4 and 5a. The somewhat sheltered transect 5 and the exposed transects 1 and 2 had the highest biomasses of individuals. The biomass was high because of the bivalvia Macoma baltica which is very common in 2-5 meters depth on the sand, silt and mud bottoms. At the transects 1, 2 and 5 were found Oligochaeta which are more common in clear water. These transects had slightly less turbid water than the other transects. The biomass of Polychaeta Marenzelleria (arctia) was high at the transects 3 and 4. This species can tolerate low oxygen levels. Transect 5a is extremely shallow and located in a flad - an enclosed bay in a land uplift region that still receives sea water regularly. High biomass of chironomids (Chironomidae) were found at the transect 5a and especially the species Chironomus f. l. plumosus, which was only found at this transect, indicates high eutrofication. Depth mapping by echo sounding was carried out at a transect interval of 50 meters in the sea area that was estimated to be less than 2 meters deep. The mapping area also included a few kilometers of the lower parts of the rivers Eurajoki and Lapinjoki. The mapping material was handed to the Geological Survey of Finland for creating a depth model. It was not a surprise to the survey team that much of the measured area was deeper than 2 meters, as the depth information printed on nautical charts aims primarily at maritime safety. (orig.)

  10. 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

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

    Science.gov (United States)

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

    2013-01-01

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

  12. 黄河三角洲石油生产对东营湿地底栖动物群落结构和水质生物评价的影响%The effects of petroleum exploitation on water quality bio-assessment and benthic macro-invertebrate communities in the Yellow River Delta wetland,Dongying

    Institute of Scientific and Technical Information of China (English)

    陈凯; 肖能文; 王备新; 李俊生

    2012-01-01

    The major environmental risks associated with petroleum extraction (e. G. Oil spills and leaks) are well known. There is a lot of information on the impacts of petroleum exploration on benthic communities in foreign studies. In this study, we probed the effects of petroleum exploration on macro-invertebrate assemblages, which are important components of benthic communities in this wetland ecosystem. The object of the investigation was to provide scientific data to guide the management, ecological restoration, conservation of biodiversity, and sustainable development of aquatic ecosystems. Physicochemical variables were measured at 34 sites in the Yellow River Delta wetland, Dongying, China, in October 2009, and benthic macro-invertebrate assemblages were collected using a D-frame net and a Peterson grab. The water body in the study area was oligohaline, its salinity ranging between 0. 05 and 5 ppt. A total of 84 macro-invertebrate taxa, belonging to 70 genera, 41 families, 12 orders, 6 classes, and 3 phyla, were collected. Insecta comprised 52.4% of all benthic invertebrate taxa, of which Odonata and Diptera accounted for 23% and 24% , respectively. The structure anddiversity of macro-invertebrate assemblages were expressed using the Shannon-Wiener index, the Margalef index and the dominance index. Water quality was assessed by the Shannon-Wiener index and the biotic index. The dominant species at most of the sites were either Chironomus spp. Or Glyptotendipes spp. With overall dominance indices of 0. 0315 and 0. 0522, respectively. Pearson correlation analysis showed that the Shannon-Wiener index was negatively correlated with total nitrogen (TN) (r=-0.446, P = 0.02) but was not correlated with any of the other physicochemical variables measured. The biotic index was not correlated with any of the physicochemical variables. The numbers of molluscan taxa were negatively correlated with salinity (r= -0.422, P = 0.028) and positively correlated with pH (r = 0.435, P