Cytological and cytochemical characterization of the polytene chromosomes of Chironomus sancticaroli (Diptera: chironomidae)

International Nuclear Information System (INIS)

Freitas, F. de; Leoncini, O.

1985-01-01

The chromosome complement of a Brazilian Chironomus Species, C. Sancticaroli, was analyzed cytochemically. The polytene Chromosomes were identified and characterized and the nucleolus organizer regions (NORs) were located by a technique of in situ hybridization and immunofluorescence. Constitutive heterochromatin and its distribution in relation to the NORs were studied. (Author) [pt

What Food and Feeding Rates are Optimum for the Chironomus dilutus Sediment Toxicity Test Method?

Science.gov (United States)

Laboratory tests with benthic macroinvertebrates are commonly used to assess the toxicity of both contaminated sediments and individual chemicals. Among the standard procedures for benthic macroinvertebrates are 10-d, 20-d, and life cycle exposures using the midge, Chironomus ...

Life cycle responses of the midge Chironomus riparius to polycyclic aromatic compound exposure

Energy Technology Data Exchange (ETDEWEB)

Paumen, Miriam Leon [Department of Aquatic Ecology and Ecotoxicology, Institute of Biodiversity and Ecosystem Dynamics (IBED), University of Amsterdam, Kruislaan 320, 1098 SM Amsterdam (Netherlands)], E-mail: mleon@science.uva.nl; Borgman, Eefje [Department of Aquatic Ecology and Ecotoxicology, Institute of Biodiversity and Ecosystem Dynamics (IBED), University of Amsterdam, Kruislaan 320, 1098 SM Amsterdam (Netherlands); Kraak, Michiel H.S. [Department of Aquatic Ecology and Ecotoxicology, Institute of Biodiversity and Ecosystem Dynamics (IBED), University of Amsterdam, Kruislaan 320, 1098 SM Amsterdam (Netherlands)], E-mail: castella@science.uva.nl; Gestel, Cornelis A.M. van [Department of Animal Ecology, Institute of Ecological Sciences (IEW), Vrije Universiteit Amsterdam, de Boelelaan 1085, 1081 HV Amsterdam (Netherlands)], E-mail: kees.van.gestel@falw.vu.nl; Admiraal, Wim [Department of Aquatic Ecology and Ecotoxicology, Institute of Biodiversity and Ecosystem Dynamics (IBED), University of Amsterdam, Kruislaan 320, 1098 SM Amsterdam (Netherlands)

2008-03-15

During acute exposure, polycyclic aromatic compounds (PACs) act mainly by narcosis, but during chronic exposure the same compounds may exert sublethal life cycle effects. The aim of this study was therefore to evaluate the chronic effects of sediment spiked PACs on the emergence of the midge Chironomus riparius. Three isomer pairs were selected, and 28-day LC{sub 50} values and 50% emergence times (EMt{sub 50}) were determined. Concentration-response relationships were observed for phenanthrene, acridine, phenanthridine and acridone. Anthracene and phenanthridone had no effect on total emergence, but did cause a delay in emergence. Calculated porewater LC{sub 50} values correlated well with logK{sub ow} values, suggesting narcosis as mode of action. In contrast, effect concentrations for delay in emergence (EMt{sub 50}) deviated from narcosis, suggesting a specific mode of action during chronic exposure. It is concluded that emergence is a powerful endpoint to detect life cycle effects of PACs on a key sediment inhabiting invertebrate. - Emergence of Chironomus riparius is a sensitive endpoint to detect life cycle effects of PACs.

The importance of excretion by Chironomus larvae on the internal loads of nitrogen and phosphorus in a small eutrophic urban reservoir

Directory of Open Access Journals (Sweden)

R. Henry

Full Text Available Measurements of ammonium and phosphate excretion by the Chironomus larvae were conducted in order to evaluate the importance of these chironomids for the internal loads of a small eutrophic urban reservoir. Ammonium and phosphate excretion rates by Chironomus larvae of small size (6-10 mm total length were significantly higher than those of the Chironomids having medium (9-11 mm and large (11-16 mm sizes. A dependence in relation to temperature was recorded for the ammonium and phosphate excretions that was significantly higher at 25 °C than at 20 and 15 °C. Through a linear relation between biomass (dry weight and total length and, between excretion and biomass and, data on chironomids densities, after an intense sampling in 33 sites distributed all along the reservoir bottom, the mean phosphate and ammonium excretion rates corresponded to 2,014 ± 5,134 µg.m-2/day and 1,643 ± 3,974 µg.m-2/day, respectively. Considering the mean biomass (34 mg.m-2 of Chironomus, the lake area (88,156 m² and the mean excretion rates, the contribution of benthic chironomids to the internal loads would be 181 KgP and 147 KgN. for the sampling months (October-November 1998. These values showed that the internal loads by excretion from Chironomus larvae correspond to approximately 33% of the external loads of phosphorus in the lake and, in the case of nitrogen, to only 5%.

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.

Cytogenetic characteristics of Chironomus balatonicus Devai, Wulker, Scholl (Diptera, Chironomidae) from the Chernobyl region

International Nuclear Information System (INIS)

Michailova, P.; Petrova, N.

1994-01-01

A cytogenetic analysis was carried out on a population of Chironomus balatonicus (Chironomidae, Diptera) from Chernobyl, a highly radioactive area of the Kiev region. Several chromosomal aberrations were established unique to a population of Chironomus balatonicus living in an area contaminated by radioactive waste. Five new heterozygous inversions, deficiencies in arms C, D, E, F and chromatid breaks were found in the irradiated population but not in nonirradiated populations. A pericentric inversion in chromosome AB occurred at a relatively high frequency. Genome aberrations expressed by a heterochromatized 'B' chromosome were evident. In the irradiated and nonirradiated populations common inversions occurred showing variation in their frequency depending on specific environmental conditions. The somatic and also the germ cells were characterized by a number of heteropycnotic nuclei and vacuolized chromosomes. Both the somatic and germ cells showed changes in the structural and functional organization of heterochromatin and this was particularly marked in the telomeric sectors of the chromosomes. The heterochromatin which is extremely sensitive to radioactivity appears to protect euchromatin from adverse environmental conditions

Chironomus polonicus sp. n. (Diptera: Chironomidae) from southern Poland.

Science.gov (United States)

Michailova, Paraskeva; Kownacki, Andrzej; Langton, Peter H

2013-01-10

The paper describes larval, pupal and adult morphology as well as the karyotype of Chironomus polonicus sp. n. from southern Poland. The material has been obtained from reared egg masses collected in Bolesław pool, near Kraków. The species belongs to the pseudothummi cytocomplex with 2n = 8 and chromosome arm combinations AE, BF, CD, G. Several homozygous inversions distinguish arm A of the new species from that of C. pseudothummi Strenzke. Arm F is similar to that of C. aprilinus Meigen and differs from it by few steps of homozygous inversions. Few morphological differences in the pupa and adult are also presented.

Genotoxic effect of copper on salivary gland polytene chromosomes of Chironomus riparius Meigen 1804 (Diptera, Chironomidae)

Energy Technology Data Exchange (ETDEWEB)

Michailova, P. [Institute of Zoology, Bulgarian Academy of Sciences, 1 Tzar Osvoboditel boul., Sofia 1000 (Bulgaria)]. E-mail: michailova@zoology.bas.bg; Petrova, N. [Institute of Zoology, Russian Academy of Sciences, St. Petersburg, 199034, Universit. nab. 1, Russia (Russian Federation); Ilkova, J. [Institute of Zoology, Bulgarian Academy of Sciences, 1 Tzar Osvoboditel boul., Sofia 1000 (Bulgaria); Bovero, S. [Department of Animal Biology, University of Turin, via Albertina 13, Turin (Italy); Brunetti, S. [Department of Animal Biology, University of Turin, via Albertina 13, Turin (Italy); White, K. [School of Biological Sciences, University of Manchester, Manchester M13 9PT (United Kingdom); Sella, G. [Department of Animal Biology, University of Turin, via Albertina 13, Turin (Italy)

2006-11-15

The genotoxic action of copper (Cu) on the polytene chromosomes of Chironomus riparius was investigated by analysing structural and functional chromosome aberrations of fourth instars larvae hatched from eggs subject to acute (48 h) exposure with three environmentally relevant concentrations of aqueous Cu (0.005, 0.01, 0.05 mg/l). A dose dependent relationship was observed between Cu concentration and frequency of chromosomal aberrations. A significantly higher frequency of functional alterations, specifically decondensed centromeres and telomeres, and reduction in activity of Balbiani rings, was observed in treated material compared to control. A comparison of breakpoints resulting from treatment with chromium and lead from earlier studies with those Cu-induced identified a series of chromosomal weak points particularly vulnerable to trace metals. We also show that the appearance of structural and functional chromosome aberrations are more sensitive indicators of acute Cu toxicity in chironomid larvae than changes in external morphology. - Acute exposure of Chironomus eggs to copper resulted in changes in chromosome structure and function.

Genotoxic effect of copper on salivary gland polytene chromosomes of Chironomus riparius Meigen 1804 (Diptera, Chironomidae)

International Nuclear Information System (INIS)

Michailova, P.; Petrova, N.; Ilkova, J.; Bovero, S.; Brunetti, S.; White, K.; Sella, G.

2006-01-01

The genotoxic action of copper (Cu) on the polytene chromosomes of Chironomus riparius was investigated by analysing structural and functional chromosome aberrations of fourth instars larvae hatched from eggs subject to acute (48 h) exposure with three environmentally relevant concentrations of aqueous Cu (0.005, 0.01, 0.05 mg/l). A dose dependent relationship was observed between Cu concentration and frequency of chromosomal aberrations. A significantly higher frequency of functional alterations, specifically decondensed centromeres and telomeres, and reduction in activity of Balbiani rings, was observed in treated material compared to control. A comparison of breakpoints resulting from treatment with chromium and lead from earlier studies with those Cu-induced identified a series of chromosomal weak points particularly vulnerable to trace metals. We also show that the appearance of structural and functional chromosome aberrations are more sensitive indicators of acute Cu toxicity in chironomid larvae than changes in external morphology. - Acute exposure of Chironomus eggs to copper resulted in changes in chromosome structure and function

/sup 3/H-UTP incorporation in polytene chromosomes of Chironomus permeabilized cells

Energy Technology Data Exchange (ETDEWEB)

Diez, J L; de la Torre, C [Consejo Superior de Investigacionis Cientificas, Madrid (Spain). Inst. Biologia Celular

1979-01-01

A method is described that allows the cytologic detection of the transcriptional activity of endogenous RNA polymerase in fixed Chironomus polytene chromosomes. /sup 3/H-UTP is preferentially incorporated onto nucleoli and Balbiani rings where transcription is specially high. The former incorporation was sensitive to actinomycin D while incorporation on Balbiani rings was sensitive to ..cap alpha..-amanitin. The label pattern and frequency resemble those detected by /sup 3/H-uridine incorporation in the living state.

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

Directory of Open Access Journals (Sweden)

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.

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

Karyotype characteristics and polymorphism peculiarities of Chironomus bernensis Wülker & Klötzli, 1973 (Diptera, Chironomidae) from the Central Caucasus and Ciscaucasia

Science.gov (United States)

Karmokov, Mukhamed Kh.; Polukonova, Natalia V.; Sinichkina, Olga V.

2015-01-01

Abstract Data about the karyotype characteristics, features of chromosomal polymorphism and larval morphology of populations of Chironomus bernensis Wülker & Klötzli, 1973 (Diptera, Chironomidae) from the Central Caucasus (the northern macroslope) and Ciscaucasia are presented. The characteristics of the pericentromeric regions of the long chromosomes of this species from Caucasian populations were very similar to the ones from some European populations (from Poland and Italy), but differed from Swiss and Siberian populations. In the North Caucasian populations 10 banding sequences were found: two in arms A, C, and E, and one in arms B, D, F, and G. Nine of them were already known for this species, and one, berC2, is described for the first time. Cytogenetic distances between all the studied populations of Chironomus bernensis show that close geographical location of all studied populations from the Central Caucasus and Ciscaucasia is reflected in their similar cytogenetic structure, but on the other hand, that they are more closely related to populations from Europe than to populations from Western Siberia. At the same time, all studied larvae from Caucasian populations have a four-bladed premandible, instead of a two-bladed one, as in the description of Chironomus bernensis from Switzerland (Wülker and Klötzli 1973, Polukonova 2005c). These peculiarities may indicate the relative isolation of the Caucasus from the viewpoint of microevolution. Further research on karyological and morphological characteristics of Chironomus bernensis from geographically distant regions is necessary as there is a possibility that the presently known species is actually polytypic and consists of several sibling species. PMID:26312128

Study of the role of biotic and abiotic factors in modifying metal accumulation by Chironomus (Diptera: Chironomidae)

Energy Technology Data Exchange (ETDEWEB)

Krantzberg, G.B.

1987-01-01

The author examined the variability in metal bioaccumulation by chironomids collected from sites that differed in the extent of metal and acid loadings. Bioaccumulation by Chironomus was related to both biotic and abiotic factors. Metal accumulation was age and weight dependent. Aluminum, Ca, and Fe concentrations increased with age, Cd and Ni decreased, and Cu, Mn, Pb, and Zn remained constant with age. Calcium, Fe, and Ni concentration increased with weight, Cd decrease, and Cu, Mn, and Zn remained constant with weight. Age and weight effects on metal accumulation were identified as a potential source of spacial and temporal variability in tissue concentrations. Metal regulation differed between populations of Chironomus. Lead and Cd were not regulated, Zn was regulated, and larvae from a Cu and Ni contaminated system appeared to regulate Cu and Ni. X-ray probe microanalysis provided further support that metal metabolism differed between population, and results from laboratory experiments suggested that populations differed in relation to metal tolerance. There was evidence that pH modified metal accumulation.

The Evolution of SINEs and LINEs in the genus Chironomus (Diptera).

Science.gov (United States)

Papusheva, Ekaterina; Gruhl, Mary C; Berezikov, Eugene; Groudieva, Tatiana; Scherbik, Svetlana V; Martin, Jon; Blinov, Alexander; Bergtrom, Gerald

2004-03-01

Genomic DNA amplification from 51 species of the family Chironomidae shows that most contain relatives of NLRCth1 LINE and CTRT1 SINE retrotransposons first found in Chironomus thummi. More than 300 cloned PCR products were sequenced. The amplified region of the reverse transcriptase gene in the LINEs is intact and highly conserved, suggesting active elements. The SINEs are less conserved, consistent with minimal/no selection after transposition. A mitochondrial gene phylogeny resolves the Chironomus genus into six lineages (Guryev et al. 2001). LINE and SINE phylogenies resolve five of these lineages, indicating their monophyletic origin and vertical inheritance. However, both the LINE and the SINE tree topologies differ from the species phylogeny, resolving the elements into "clusters I-IV" and "cluster V" families. The data suggest a descent of all LINE and SINE subfamilies from two major families. Based on the species phylogeny, a few LINEs and a larger number of SINEs are cladisitically misplaced. Most misbranch with LINEs or SINEs from species with the same families of elements. From sequence comparisons, cladistically misplaced LINEs and several misplaced SINEs arose by convergent base substitutions. More diverged SINEs result from early transposition and some are derived from multiple source SINEs in the same species. SINEs from two species (C. dorsalis, C. pallidivittatus), expected to belong to the clusters I-IV family, branch instead with cluster V family SINEs; apparently both families predate separation of cluster V from clusters I-IV species. Correlation of the distribution of active SINEs and LINEs, as well as similar 3' sequence motifs in CTRT1 and NLRCth1, suggests coevolving retrotransposon pairs in which CTRT1 transposition depends on enzymes active during NLRCth1 LINE mobility.

Benthic communities in inland salinized waters with different salinities and nutrient concentrations and the ecology of Chironomus aprilinus (Diptera: Chironomidae) in the Czech Republic.

Czech Academy of Sciences Publication Activity Database

Matěna, Josef; Šímová, I.; Brom, J.; Novotná, K.

2016-01-01

Roč. 113, January (2016), s. 122-129 E-ISSN 1802-8829 Institutional support: RVO:60077344 Keywords : Diptera * Chironomidae * Chironomus aprilinus * coal mining * hydric restoration * saline inland waters * fertilization Subject RIV: EH - Ecology, Behaviour Impact factor: 1.167, year: 2016

Chironomus plumosus' påvirkning af næringsstofflukse i restaurerede søer

DEFF Research Database (Denmark)

Kristensen, T. B.; Reitzel, K.; Andersen, F. Ø.

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....

Contaminated sediments and bioassay responses of three macroinvertebrates, the midge larva Chironomus riparius, the water louse Asellus aquaticus and the mayfly nymph Ephoron virgo

NARCIS (Netherlands)

Lange, de H.J.; Haas, de E.M.; Maas, H.; Peeters, E.T.H.M.

2005-01-01

Bioassays are widely used to estimate ecological risks of contaminated sediments. We compared the results of three whole sediment bioassays, using the midge larva Chironomus riparius, the water louse Asellus aquaticus, and the mayfly nymph Ephoron virgo. We used sediments from sixteen locations in

Acute toxicity tests with Daphnia magna, Americamysis bahia, Chironomus riparius and Gammarus pulex and implications of new EU requirenments for the aquatic effect assessment of insecticides

NARCIS (Netherlands)

Brock, T.C.M.; Wijngaarden, van R.P.A.

2012-01-01

Threshold concentrations for treatment related effects of 31 insecticides, as derived from aquatic micro-/mesocosm tests, were used to calibrate the predictive value of the European Tier-1 acute effect assessment on basis of laboratory toxicity tests with Daphnia magna, Chironomus spp., Americamysis

A novel computational approach of image analysis to quantify behavioural response to heat shock in Chironomus Ramosus larvae (Diptera: Chironomidae

Directory of Open Access Journals (Sweden)

Bimalendu B. Nath

2015-07-01

Full Text Available All living cells respond to temperature stress through coordinated cellular, biochemical and molecular events known as “heat shock response” and its genetic basis has been found to be evolutionarily conserved. Despite marked advances in stress research, this ubiquitous heat shock response has never been analysed quantitatively at the whole organismal level using behavioural correlates. We have investigated behavioural response to heat shock in a tropical midge Chironomus ramosus Chaudhuri, Das and Sublette. The filter-feeding aquatic Chironomus larvae exhibit characteristic undulatory movement. This innate pattern of movement was taken as a behavioural parameter in the present study. We have developed a novel computer-aided image analysis tool “Chiro” for the quantification of behavioural responses to heat shock. Behavioural responses were quantified by recording the number of undulations performed by each larva per unit time at a given ambient temperature. Quantitative analysis of undulation frequency was carried out and this innate behavioural pattern was found to be modulated as a function of ambient temperature. Midge larvae are known to be bioindicators of aquatic environments. Therefore, the “Chiro” technique can be tested using other potential biomonitoring organisms obtained from natural aquatic habitats using undulatory motion as a behavioural parameter.

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

International Nuclear Information System (INIS)

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

2016-01-01

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 0.1 mg/L 4MBC but returned to normal levels after exposure to mixtures of 4MBC with 0.1, 1, and 10 mg/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. - Highlights: • Chironomus riparius is sensitive to UV filter binary mixtures. • UV filters binary mixtures show antagonism on survival of 4th instar larvae. • BP-3 and OMC antagonize the stimulatory effect of 4MBC on EcR gene. • 4MBC, OMC, and BP-3 induce hsp70

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

Energy Technology Data Exchange (ETDEWEB)

Ozáez, Irene; Morcillo, Gloria; Martínez-Guitarte, José-Luis, E-mail: jlmartinez@ccia.uned.es

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 0.1 mg/L 4MBC but returned to normal levels after exposure to mixtures of 4MBC with 0.1, 1, and 10 mg/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. - Highlights: • Chironomus riparius is sensitive to UV filter binary mixtures. • UV filters binary mixtures show antagonism on survival of 4th instar larvae. • BP-3 and OMC antagonize the stimulatory effect of 4MBC on EcR gene. • 4MBC, OMC, and BP-3 induce hsp70

Cytochrome P450 genes from the aquatic midge Chironomus tentans: Atrazine-induced up-regulation of CtCYP6EX3 contributing to oxidative activation of chlorpyrifos

Science.gov (United States)

The open reading frames of 19 cytochrome P450 monooxygenase (CYP) genes were sequenced from Chironomus tentans, a commonly used freshwater invertebrate model. Functional analysis of CtCYP6EX3 confirmed its atrazine-induced oxidative activation for chlorpyrifos by using a nanoparticle-based RNA inter...

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

Energy Technology Data Exchange (ETDEWEB)

Faria, Mafalda S. [CESAM and Departamento de Biologia da Universidade de Aveiro, Campus de Santiago, 3810-193 Aveiro (Portugal)], E-mail: mafaldafaria@sapo.pt; Lopes, Ricardo J. [CIBIO, Centro de Investigacao em Biodiversidade e Recursos Geneticos, Campus Agrario de Vairao, 4485-661 Vairao (Portugal); Malcato, Joao; Nogueira, Antonio J.A.; Soares, Amadeu M.V.M. [CESAM and Departamento de Biologia da Universidade de Aveiro, Campus de Santiago, 3810-193 Aveiro (Portugal)

2008-01-15

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.

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)

Faria, Mafalda S.; Lopes, Ricardo J.; Malcato, Joao; Nogueira, Antonio J.A.; Soares, Amadeu M.V.M.

2008-01-01

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

Effects of pH on the toxicity and uptake of [14C]lindane in the midge, Chironomus riparius

International Nuclear Information System (INIS)

Fisher, S.W.

1985-01-01

The toxicity of the insecticide, lindane, was measured in the midge, Chironomus riparius, at pH 4, 6, and 8 with the finding that lindane is significantly more toxic at pH 6 than at pH 4 and 8. The higher toxicity of lindane at pH 6 is a product of two factors. First the penetration of the compound into the midge is lower at pH 4 than at pH 6 and 8. Second, a greater percentage of total radioactivity is contributed by parent compound at pH 6

Effect of gamma irradiation on larval longevity of Chironomus Riparius Meigen. Vol. 4

International Nuclear Information System (INIS)

Samira, A.A.; El-Halfawy, N.; El-Ebiarie, A.S.

1996-01-01

Whole body irradiation is known to shorten the life-span of insects. This is further investigated in aquatic insect larvae, as part of a programme concerned with stress responses on these larvae. The effect of gamma rays on the longevity of different larval instars of midge Chironomus Riparius was investigated by using five doses of 1, 9, 30, 200 and 1000 Gy of gamma rays. Lt 50 (the time in days required for killing 50% of the population) was estimated using spss x programme. Data showed that irradiation decreased Lt 50 in the second, third and fourth instars in comparison to their control, while in the first instar, irradiation increased Lt 50 for all doses used. Shortening or increasing life was independent of the dose. Results were explained in terms of possibility of inhibition of enzymes. 1 fig., 1 tab

Consequences of inbreeding and reduced genetic variation on tolerance to cadmium stress in the midge Chironomus riparius

International Nuclear Information System (INIS)

Nowak, Carsten; Jost, Daniel; Vogt, Christian; Oetken, Matthias; Schwenk, Klaus; Oehlmann, Joerg

2007-01-01

Inbreeding and loss of genetic variation are considered to be major threats to small and endangered populations. The reduction of fitness due to inbreeding is believed to be more severe under stressful environmental conditions. We generated nine strains of the ecotoxicological model organism Chironomus riparius of different inbreeding levels in order to test the hypothesis that the inbreeding level and thus the degree of genome-wide homozygosity influences the life-history under cadmium exposure. Therefore, midge populations were exposed to a gradient of sediment-bound cadmium. The level of genetic variation in the used strains was assessed using microsatellite markers. In the life-cycle tests, inbreeding reduced fitness within C. riparius populations both under control and stressed conditions. However, differences between genetically diverse and impoverished strains were greatest at high cadmium exposure. Overall, inbreeding effects were not only dependent on cadmium concentrations in the sediment, but also on the life-history trait investigated. While some parameters where only affected by inbreeding, others were altered by both, inbreeding and cadmium. For the larval developmental time, a significant interaction was found between inbreeding and cadmium stress. While all strains showed a similar developmental time under control conditions, high rates of inbreeding led to a significantly delayed emergence time under high cadmium concentrations, resulting in longer generation periods and reduced population growth rates as population-relevant effects. The results show, that bioassays with C. riparius are affected by the level of inbreeding within Chironomus test strains. Pollution stress is therefore likely to affect the survival of rare and endangered populations more severe than that of large and genetically diverse ones

Effect of gamma irradiation on larval longevity of Chironomus Riparius Meigen. Vol. 4

Energy Technology Data Exchange (ETDEWEB)

Samira, A A [Dept. of Entomology, Univ. of Ain Shams., Cairo (Egypt); El-Halfawy, N [National Centre radiation Research and Technology, Cairo (Egypt); El-Ebiarie, A S [Dept. of Zoology, Fac. of Science, Univ. of Helwan., Cairi (Egypt)

1996-03-01

Whole body irradiation is known to shorten the life-span of insects. This is further investigated in aquatic insect larvae, as part of a programme concerned with stress responses on these larvae. The effect of gamma rays on the longevity of different larval instars of midge Chironomus Riparius was investigated by using five doses of 1, 9, 30, 200 and 1000 Gy of gamma rays. Lt{sub 50} (the time in days required for killing 50% of the population) was estimated using spss{sup x} programme. Data showed that irradiation decreased Lt{sub 50} in the second, third and fourth instars in comparison to their control, while in the first instar, irradiation increased Lt{sub 50} for all doses used. Shortening or increasing life was independent of the dose. Results were explained in terms of possibility of inhibition of enzymes. 1 fig., 1 tab.

Redescription of Chironomus salinarius (Diptera: Chironomidae), nuisance midges that emerged in brackish water of Jinhae-man (Bay), Kyongsangnam-do, Korea

Science.gov (United States)

Yum, Jin-Hwoa

2006-01-01

Huge numbers of non-biting midges emerged from brackish water which were made at the harbor construction field in Jinhae City, Kyongsangnam-do, Korea in late summer in 2005, and caused a serious nuisance to villagers. The midges were collected and identified as Chironomus salinarius (Kieffer, 1921). Although this species was recorded in Korea for the first time in 1998, the morphological descriptions were so brief and simple. A full redescription is made with detailed illustrations for ecological and control workers of this nuisance midge. PMID:16514284

[Nuclear protein matrix from giant nuclei of Chironomus plumosus determinates polythene chromosome organization].

Science.gov (United States)

Makarov, M S; Chentsov, Iu S

2010-01-01

Giant nuclei from salivary glands of Chironomus plumosus were treated in situ with detergent, 2 M NaCl and nucleases in order to reveal residual nuclear matrix proteins (NMP). It was shown, that preceding stabilization of non-histone proteins with 2 mM CuCl2 allowed to visualize the structure of polythene chromosomes at every stage of the extraction of histones and DNA. Stabilized NPM of polythene chromosomes maintains their morphology and banding patterns, which is observed by light and electron microscopy, whereas internal fibril net or residual nucleoli are not found. In stabilized NPM of polythene chromosomes, topoisomerase IIalpha and SMC1 retain their localization that is typical of untreated chromosomes. NPM of polythene chromosomes also includes sites of DNA replication, visualized with BrDU incubation, and some RNA-components. So, we can conclude that structure of NPM from giant nuclei is equal to NPM from normal interphase nuclei, and that morphological features of polythene chromosomes depend on the presence of NMP.

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

Cadmium transport by the gut and Malpighian tubules of Chironomus riparius

International Nuclear Information System (INIS)

Leonard, Erin M.; Pierce, Laura M.; Gillis, Patricia L.; Wood, Chris M.; O'Donnell, Michael J.

2009-01-01

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 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 μmol l -1 Cd, the tubules can secrete the entire hemolymph burden of Cd in ∼15 h.

Joint toxicity of sediment-associated permethrin and cadmium to Chironomus dilutus: The role of bioavailability and enzymatic activities

International Nuclear Information System (INIS)

Chen, Xin; Li, Huizhen; You, Jing

2015-01-01

Pyrethroid insecticides and metals commonly co-occurred in sediment and caused toxicity to benthic organisms jointly. To improve accuracy in assessing risk of the sediments contaminated by insecticides and metals, it is of great importance to understand interaction between the contaminants and reasons for the interaction. In the current study, permethrin and cadmium were chosen as representative contaminants to study joint toxicity of pyrethroids and metals to a benthic invertebrate Chironomus dilutus. A median effect/combination index-isobologram was applied to evaluate the interaction between sediment-bound permethrin and cadmium at three dose ratios. Antagonistic interaction was observed in the midges for all treatments. Comparatively, cadmium-dominated group (the ratio of toxicity contribution from permethrin and cadmium was 1:3) showed stronger antagonism than equitoxicity (1:1) and permethrin-dominated groups (3:1). The reasons for the observed antagonism were elucidated from two aspects, including bioavailability and enzymatic activity. The bioavailability of permethrin, expressed as the freely dissolved concentrations in sediment porewater and measured by solid phase microextraction, was not altered by the addition of cadmium, suggesting the change in permethrin bioavailability was not the reason for the antagonism. On the other hand, the activities of metabolic enzymes, glutathione S-transferase and carboxylesterase in the midges which were exposed to mixtures of permethrin and cadmium were significantly higher than those in the midges exposed to permethrin solely. Cadmium considerably enhanced the detoxifying processes of permethrin in the midges, which largely explained the observed antagonistic interaction between permethrin and cadmium. - Highlights: • Sediment-bound permethrin and cadmium acted antagonistically to Chironomus dilutus. • Antagonism of permethrin and cadmium to the midges was noted at various dose ratios. • Addition of cadmium did

Life-cycle effects of sediment-associated uranium on Chironomus riparius (diptera: chironomidae)

Energy Technology Data Exchange (ETDEWEB)

Dias, V.; Ksas, B.; Camilleri, V.; Bonzom, J.M. [CEA Cadarache (DEI/SECRE/LRE), Laboratory of Radioecology and Ecotoxicology, Institute for Radioprotection and Nuclear Safety, 13 - Saint-Paul-lez-Durance (France)

2004-07-01

In aquatic ecosystems, sediments function as reservoir for many of the more persistent chemicals that are introduced into surface waters. Sediments provide a habitat for various benthic macro-invertebrates, which are exposed to sediment-associated chemicals both directly and via food intake. These chemicals may be directly toxic to benthic macro-invertebrates and can be integrated into food chain. Benthic macro-invertebrates play an important role in the ecosystem structure and functioning. In particular, they represent an important component of aquatic food chains. Among the non biologically essential metals, data concerning uranium fate and effects on freshwater benthic invertebrates are sparse. The present study aimed to estimate effects of a chronic uranium exposure on life-cycle traits of Chironomus riparius. To achieve this goal, (i) first instar larvae were exposed to a series of concentrations of uranium via the sediment, and (ii) a number of developmental (e.g. growth) and reproductive (e.g. emergence, fecundity, viability) endpoints, through parental and into F1 generations, were evaluated. Within the framework of ecological risk assessment, these data will help the derivation of a sediment guideline value for uranium that does not currently exist in France or elsewhere due to a lack of toxicity data. (author)

Life-cycle effects of sediment-associated uranium on Chironomus riparius (diptera: chironomidae)

International Nuclear Information System (INIS)

Dias, V.; Ksas, B.; Camilleri, V.; Bonzom, J.M.

2004-01-01

In aquatic ecosystems, sediments function as reservoir for many of the more persistent chemicals that are introduced into surface waters. Sediments provide a habitat for various benthic macro-invertebrates, which are exposed to sediment-associated chemicals both directly and via food intake. These chemicals may be directly toxic to benthic macro-invertebrates and can be integrated into food chain. Benthic macro-invertebrates play an important role in the ecosystem structure and functioning. In particular, they represent an important component of aquatic food chains. Among the non biologically essential metals, data concerning uranium fate and effects on freshwater benthic invertebrates are sparse. The present study aimed to estimate effects of a chronic uranium exposure on life-cycle traits of Chironomus riparius. To achieve this goal, (i) first instar larvae were exposed to a series of concentrations of uranium via the sediment, and (ii) a number of developmental (e.g. growth) and reproductive (e.g. emergence, fecundity, viability) endpoints, through parental and into F1 generations, were evaluated. Within the framework of ecological risk assessment, these data will help the derivation of a sediment guideline value for uranium that does not currently exist in France or elsewhere due to a lack of toxicity data. (author)

Karyotype characteristics and polymorphism peculiarities of Chironomus bernensis Wülker & Klötzli, 1973 (Diptera, Chironomidae from the Central Caucasus and Ciscaucasia

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Mukhamed Kh. Karmokov

2015-06-01

Full Text Available Data about the karyotype characteristics, features of chromosomal polymorphism and larval morphology of populations of Chironomus bernensis Wülker & Klötzli, 1973 (Diptera, Chironomidae from the Central Caucasus (the northern macroslope and Ciscaucasia are presented. The characteristics of the pericentromeric regions of the long chromosomes of this species from Caucasian populations were very similar to the ones from some European populations (from Poland and Italy, but differed from Swiss and Siberian populations. In the North Caucasian populations 10 banding sequences were found: two in arms A, C, and E, and one in arms B, D, F, and G. Nine of them were already known for this species, and one, berC2, is described for the first time. Cytogenetic distances between all the studied populations of Ch. bernensis show that close geographical location of all studied populations from the Central Caucasus and Ciscaucasia is reflected in their similar cytogenetic structure, but on the other hand, that they are more closely related to populations from Europe than to populations from Western Siberia. At the same time, all studied larvae from Caucasian populations have a four-bladed premandible, instead of a two-bladed one, as in the description of Ch. bernensis from Switzerland (Wülker and Klötzli 1973, Polukonova 2005c. These peculiarities may indicate the relative isolation of the Caucasus from the viewpoint of microevolution. Further research on karyological and morphological characteristics of Chironomus bernensis from geographically distant regions is necessary as there is a possibility that the presently known species is actually polytypic and consists of several sibling species.

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

International Nuclear Information System (INIS)

Dias, V.

2010-01-01

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)

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. Copyright © 2011 Elsevier Ltd. All rights reserved.

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)

Doi, Hideyuki; Kikuchi, Eisuke; Shikano, Shuichi

2001-01-01

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. δ 13 C 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)

In situ and laboratory bioassays with Chironomus riparius larvae to assess toxicity of metal contamination in rivers: the relative toxic effect of sediment versus water contamination.

Science.gov (United States)

Faria, Mafalda S; Lopes, Ricardo J; Nogueira, António J A; Soares, Amadeu M V M

2007-09-01

We used bioassays employing head capsule width and body length increase of Chironomus riparius larvae as end points to evaluate metal contamination in streams. Bioassays were performed in situ near an abandoned Portuguese goldmine in the spring of 2003 and 2004. Bioassays also were performed under laboratory conditions with water and sediment collected from each stream to verify if laboratory bioassays could detect in situ toxicity and to evaluate the relative contribution of sediment and water to overall toxicity. We used field sediments with control water and control sediments with field water to discriminate between metal contamination in water and sediment. Field water with dry and sieved, organic matter-free, and nontreated sediments was used to determine the toxicity of heavy metals that enter the organism through ingested material. In both in situ and laboratory bioassays, body length increase was significantly inhibited by metal contamination, whereas head capsule width was not affected. Body length increase was more affected by contaminated sediment compared to contaminated water. The lowest-effect level of heavy metals was observed in the dry and sieved sediment that prevented ingestion of sediment particles by larvae. These results suggest that body length increase of C. riparius larvae can be used to indicate the impact of metal contamination in rivers. Chironomus riparius larvae are more affected by heavy metals that enter the organism through ingested sediment than by heavy metals dissolved in the water column. Nevertheless, several factors, such as the particle size and organic matter of sediment, must be taken into account.

Genotoxic effects of vinclozolin on the aquatic insect Chironomus riparius (Diptera, Chironomidae).

Science.gov (United States)

Aquilino, Mónica; Sánchez-Argüello, Paloma; Martínez-Guitarte, José-Luis

2018-01-01

Vinclozolin (Vz) is a pollutant found in aquatic environments whose antiandrogenic effects in reproduction are well known in mammals. Although its reproductive effects have been less studied in invertebrates, other effects, including genotoxicity, have been described. Therefore, in this work, we studied the genotoxic effects of Vz in the freshwater benthic invertebrate Chironomus riparius. DNA damage was evaluated with the comet assay (tail area, olive moment, tail moment and % DNA in tail), and the transcriptional levels of different genes involved in DNA repair (ATM, NLK and XRCC1) and apoptosis (DECAY) were measured by RT-PCR. Fourth instar larvae of C. riparius, were exposed to Vz for 24 h at 20 and 200 μg/L. The Vz exposures affected the DNA integrity in this organism, since a dose-response relationship occurred, with DNA strand breaks significantly increased with increased dose for tail area, olive moment and tail moment parameters. Additionally, the lower concentration of Vz produced a significant induction of the transcripts of three genes under study (ATM, NLK and XRCC1) showing the activation of the cellular repair mechanism. In contrast, the expression of these genes with the highest concentration were downregulated, indicating failure of the cellular repair mechanism, which would explain the higher DNA damage. These data report for the first time the alterations of Vz on gene transcription of an insect and confirm the potential genotoxicity of this compound on freshwater invertebrates. Copyright © 2017 Elsevier Ltd. All rights reserved.

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.

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

Energy Technology Data Exchange (ETDEWEB)

Doi, Hideyuki [Tohoku Univ., Sendai (Japan). Graduate School of Science; Kikuchi, Eisuke; Shikano, Shuichi

2001-12-01

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. {delta}{sup 13}C 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)

[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.

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

International Nuclear Information System (INIS)

Tyler Mehler, W.; Schuler, Lance J.; Lydy, Michael J.

2008-01-01

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

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.

A contribuição de Osvaldo Rodrigues da Cunha (1928-2011 à Herpetologia

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Teresa Cristina Avila-Pires

Full Text Available O texto faz breve descrição da obra herpetológica de Osvaldo Rodrigues da Cunha (1928-2011, pesquisador do Museu Paraense Emílio Goeldi, Brasil. Destaca sua formação intelectual, os principais trabalhos, a organização da coleção herpetológica do Museu Goeldi e a criação do Setor de Herpetologia da instituição. Também destaca as espécies descritas por Cunha e colaboradores.

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

Science.gov (United States)

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

1996-01-01

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

The use of Chironomus riparius larvae to assess effects of pesticides from rice fields in adjacent freshwater ecosystems.

Science.gov (United States)

Faria, Mafalda S; Nogueira, António J A; Soares, Amadeu M V M

2007-06-01

A bioassay with Chironomus riparius larvae, using larval development and growth as endpoints, was carried out inside a rice field and in the adjacent wetland channel in Portugal, during pesticide treatments (molinate, endosulfan and propanil) to determine impact caused by pesticide contamination in freshwater ecosystems. The bioassay was also performed under laboratory conditions, to assess whether in situ and laboratory bioassays demonstrated comparable results. Growth was inhibited by concentrations of endosulfan (2.3 and 1.9 microgL(-1) averages) in water from rice field in both the field and laboratory, and by concentrations of endosulfan (0.55 and 0.76 microgL(-1) averages) in water from the wetland channel in the laboratory bioassay, while development was not affected. C. riparius larvae were not affected by molinate and propanil concentrations. The results indicate that endosulfan treatments in rice fields may cause an ecological impairment in adjacent freshwater ecosystems. The results also indicate that laboratory testing can be used to assess in situ toxicity caused by pesticide contamination.

Influence of Chironomus riparius (Diptera, Chironomidae) and Tubifex tubifex (Annelida, Oligochaeta) on oxygen uptake by sediments. Consequences of uranium contamination

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Lagauzere, S. [Laboratoire de Radioecologie et d' Ecotoxicologie, Institut de Radioprotection et de Surete Nucleaire (IRSN), DEI/SECRE/LRE, Cadarache 186, BP 3, F-13115 Cedex, Saint Paul Lez Durance (France)], E-mail: lagauzere@gmail.com; Pischedda, L.; Cuny, P. [Laboratoire de Microbiologie, Geochimie et Ecologie Marines, UMR 6117 CNRS/COM/Universite de la Mediterranee, Campus de Luminy, Case 901, F-13288 Cedex 09, Marseille (France); Gilbert, F. [EcoLab, Laboratoire d' Ecologie Fonctionnelle, UMR 5245 CNRS/INP/Universite Paul Sabatier, 29 Rue Jeanne Marvig, F-31055 Cedex 4, Toulouse (France); Stora, G. [Laboratoire de Microbiologie, Geochimie et Ecologie Marines, UMR 6117 CNRS/COM/Universite de la Mediterranee, Campus de Luminy, Case 901, F-13288 Cedex 09, Marseille (France); Bonzom, J.-M. [Laboratoire de Radioecologie et d' Ecotoxicologie, Institut de Radioprotection et de Surete Nucleaire (IRSN), DEI/SECRE/LRE, Cadarache 186, BP 3, F-13115 Cedex, Saint Paul Lez Durance (France)

2009-04-15

The diffusive oxygen uptake (DOU) of sediments inhabited by Chironomus riparius and Tubifex tubifex was investigated using a planar oxygen optode device, and complemented by measurements of bioturbation activity. Additional experiments were performed within contaminated sediments to assess the impact of uranium on these processes. After 72 h, the two invertebrate species significantly increased the DOU of sediments (13-14%), and no temporal variation occurred afterwards. Within contaminated sediments, it was already 24% higher before the introduction of the organisms, suggesting that uranium modified the sediment biogeochemistry. Although the two species firstly reacted by avoidance of contaminated sediment, they finally colonized it. Their bioturbation activity was reduced but, for T. tubifex, it remained sufficient to induce a release of uranium to the water column and an increase of the DOU (53%). These results highlight the necessity of further investigations to take into account the interactions between bioturbation, microbial metabolism and pollutants. - This study highlights the ecological importance of bioturbation in metal-contaminated sediments.

Influence of Chironomus riparius (Diptera, Chironomidae) and Tubifex tubifex (Annelida, Oligochaeta) on oxygen uptake by sediments. Consequences of uranium contamination

International Nuclear Information System (INIS)

Lagauzere, S.; Pischedda, L.; Cuny, P.; Gilbert, F.; Stora, G.; Bonzom, J.-M.

2009-01-01

The diffusive oxygen uptake (DOU) of sediments inhabited by Chironomus riparius and Tubifex tubifex was investigated using a planar oxygen optode device, and complemented by measurements of bioturbation activity. Additional experiments were performed within contaminated sediments to assess the impact of uranium on these processes. After 72 h, the two invertebrate species significantly increased the DOU of sediments (13-14%), and no temporal variation occurred afterwards. Within contaminated sediments, it was already 24% higher before the introduction of the organisms, suggesting that uranium modified the sediment biogeochemistry. Although the two species firstly reacted by avoidance of contaminated sediment, they finally colonized it. Their bioturbation activity was reduced but, for T. tubifex, it remained sufficient to induce a release of uranium to the water column and an increase of the DOU (53%). These results highlight the necessity of further investigations to take into account the interactions between bioturbation, microbial metabolism and pollutants. - This study highlights the ecological importance of bioturbation in metal-contaminated sediments

The Use of the Developmental Rate of the Aquatic Midge Chironomus riparius (Diptera, Chironomidae) in the Assessment of the Postsubmersion Interval.

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González Medina, Alejandro; Soriano Hernando, Óscar; Jiménez Ríos, Gilberto

2015-05-01

Nonbiting midges (Diptera, Chironomidae) are the most abundant members of the fauna associated with submerged carcasses, but their use in the medicolegal context is very restricted because of their complex ontogeny. In this case, the corpse of a woman was recovered in late spring from a river in Granada (Iberian Peninsula). It showed obvious signs of long permanence in the aquatic environment and, along with pulmonary and microscopical analyses, led to the conclusion that the cause of death was drowning. Several larvae-like specimens were sampled from the scalp and later identified by morphological external features as IV instar larvae of Chironomus riparius Meigen, 1804 (Diptera, Chironomidae). Sequencing of cytochrome oxidase subunit I was performed to confirm the identification. The knowledge of the biology of C. riparius at low temperatures was critical to assess a postsubmersion interval of 16-17 days. © 2015 American Academy of Forensic Sciences.

Effects of exposure to azaarenes on emergence and mouthpart development in the midge Chironomus riparius (Diptera: Chironomidae)

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Bleeker, E.A.J.; Leslie, H.A.; Groenendijk, D.; Plans, M.; Admiraal, W.

1999-08-01

Adverse effects of azaarenes on emergence and mouthpart development of the midge Chironomus riparius were analyzed using six closely related three-ringed isomers and metabolites. Effects on growth rate were examined by comparing the average day of emergence of exposed midges with that of controls. Fluctuating asymmetry (FA) in the pecten epipharyngis was examined as a measure of developmental abnormality. Delayed emergence was found at concentrations as low as 2% of the acute LC50, so emergence day appears to be a useful sensitive parameter to quantity life cycle effects. No differences in FA were found between exposed and control larvae, although, in other studies, all compounds have been proven to be genotoxic. The differences in FA were found between exposed and control larvae, although, in other studies, all compounds have been proven to be genotoxic. The differences in the genotoxic and FA-inducing properties of these compounds indicate that different mechanisms are involved in expressing these adverse effects. This study also illustrates that the choice of the morphological parameter strongly influences the results of developmental disturbance analyses and thus the risk qualification of a potentially hazardous compound.

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

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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.

Can mouth part deformities of Chironomus riparius serve as indicators for water and sediment pollution? A laboratory approach

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Langer-Jaesrich, Miriam; Koehler, Heinz R. [Animal Physiological Ecology Dept., Univ. of Tuebingen (Germany); Gerhardt, Almut [LimCo International, Ibbenbueren (Germany)

2010-04-15

Purpose: The significance of chironomids mouthpart deformities as suitable indicators for pollutant contamination of natural waters and sediments has been investigated and discussed for several decades. Uncertainties still exist as further laboratory studies, with different pollutants and with the same experimental design are required. Materials and methods In this study, the effects of four substances (i.e., nickel chloride, chlorpyrifos, imidacloprid and thiacloprid) were tested on the mouthpart deformity rates and patterns in Chironomus riparius. These compounds were investigated either individually or in mixtures. Results and discussion No significant increase in the frequency of mouthpart deformities was found using different single substance treatments when compared to the controls. Consequently no concentration-effect relationships between substance concentration and deformity frequency were detected. In mixture experiments an increase in mouthpart deformities of C. riparius exposed to imidacloprid-thiacloprid mixtures was detected. This indicated that the effects of single substances and mixtures on mouthpart deformity frequency may differ considerably. Conclusions The findings in this study from different laboratory approaches in combination with the published literature questions the reliability of chironomids mouthpart deformities as indicators of freshwater and sediment contamination by toxic substances. (orig.)

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

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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

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

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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.

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

International Nuclear Information System (INIS)

Anderson, J.; Wiseman, S.; Franz, E.; Jones, P.; Liber, K.; Giesy, J.; Gamal El-Din, M.; Marin, J.

2010-01-01

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 O 3 /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 O 3 /L ozonated OSPW was not much different from that of the controls. Larvae exposed to 80 mg O 3 /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.

Cumulative toxicity of neonicotinoid insecticide mixtures to Chironomus dilutus under acute exposure scenarios.

Science.gov (United States)

Maloney, Erin M; Morrissey, Christy A; Headley, John V; Peru, Kerry M; Liber, Karsten

2017-11-01

Extensive agricultural use of neonicotinoid insecticide products has resulted in the presence of neonicotinoid mixtures in surface waters worldwide. Although many aquatic insect species are known to be sensitive to neonicotinoids, the impact of neonicotinoid mixtures is poorly understood. In the present study, the cumulative toxicities of binary and ternary mixtures of select neonicotinoids (imidacloprid, clothianidin, and thiamethoxam) were characterized under acute (96-h) exposure scenarios using the larval midge Chironomus dilutus as a representative aquatic insect species. Using the MIXTOX approach, predictive parametric models were fitted and statistically compared with observed toxicity in subsequent mixture tests. Single-compound toxicity tests yielded median lethal concentration (LC50) values of 4.63, 5.93, and 55.34 μg/L for imidacloprid, clothianidin, and thiamethoxam, respectively. Because of the similar modes of action of neonicotinoids, concentration-additive cumulative mixture toxicity was the predicted model. However, we found that imidacloprid-clothianidin mixtures demonstrated response-additive dose-level-dependent synergism, clothianidin-thiamethoxam mixtures demonstrated concentration-additive synergism, and imidacloprid-thiamethoxam mixtures demonstrated response-additive dose-ratio-dependent synergism, with toxicity shifting from antagonism to synergism as the relative concentration of thiamethoxam increased. Imidacloprid-clothianidin-thiamethoxam ternary mixtures demonstrated response-additive synergism. These results indicate that, under acute exposure scenarios, the toxicity of neonicotinoid mixtures to C. dilutus cannot be predicted using the common assumption of additive joint activity. Indeed, the overarching trend of synergistic deviation emphasizes the need for further research into the ecotoxicological effects of neonicotinoid insecticide mixtures in field settings, the development of better toxicity models for neonicotinoid mixture

Factors that alter the biochemical biomarkers of environmental contamination in Chironomus sancticaroli (Diptera, Chironomidae

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Débora Rebechi-Baggio

Full Text Available ABSTRACT Changes in physiology of the nervous system and metabolism can be detected through the activity of acetylcholinesterase (AChE, alpha esterase (EST-a and beta esterase (EST-ß in chironomids exposed to pollutants. However, to understand the real effect of xenobiotics on organisms, it is important to investigate how certain factors can interfere with enzyme activity. We investigated the effects of different temperatures, food stress and two steps of the enzymatic protocol on the activity of AChE, EST-a and EST-ß in Chironomus sancticaroli. In experiment of thermal stress individuals from the egg stage to the fourth larval instar were exposed to different temperatures (20, 25 and 30 °C. In food stress experiment, larvae were reared until IV instar in a standard setting (25 °C and 0.9 g weekly ration, but from fourth instar on they were divided into groups and offered different feeding regimes (24, 48 and 72 h with/without food. In sample freezing experiment, a group of samples was processed immediately after homogenization and another after freezing for 30 days. To test the effect of centrifugation on samples, enzyme activity was quantified from centrifuged and non-centrifuged samples. The activity of each enzyme reached an optimum at a different temperature. The absence of food triggered different changes in enzyme activity depending on the period of starvation. Freezing and centrifugation of the samples significantly reduced the activity of three enzymes. Based on these results we conclude that the four factors studied had an influence on AChE, EST-a and EST-ß and this influence should be considered in ecotoxicological approaches.

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

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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

Genome Instability of Chironomus riparius Mg. (Diptera, Chironomidae from Polluted Water Basins in Bulgaria

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Julia Ilkova

2014-04-01

Full Text Available Larvae of Chironomus riparius Mg. (Chironomidae, Diptera collected from two polluted water basins in Bulgaria, the Maritsa and Chaya Rivers (adjacent to Plovdiv and Asenovgrad respectively, a small pool (near Plovdiv plus controls reared in the laboratory were studied. High concentrations of the heavy metals Pb, Cu and Cd were recorded in the sediments of the polluted stations. Marked somatic structural chromosome aberrations were found in C. riparius salivary polytene chromosomes from the field stations and their frequency was significantly higher (p<0.01 compared to the control. The observed somatic chromosome changes are discussed as a response of the chironomid genome to aquatic pollution. A new cytogenetic index based on the number of aberrations found in larvae from polluted regions in comparison with the control was applied to the data to more easily evaluate the degree of heavy metal pollution in aquatic ecosystems. Our study of a polluted site near the River Chaya showed that the somatic index was very high at 3.35 for 2010 and 11.66 for 2013 compared to 0.5 in the control. The cytogenetic index was effective in showing that all studied sites were highly polluted in comparison with the control. To determine the mechanism involved in the concentration of aberration breakpoints within specific regions of the chironomid polytene chromosome the FISH method was applied. The localization of a transposable element TFB1 along the polytene chromosomes of C. riparius was analyzed and the sites of localization were compared with breakpoints of chromosome aberrations. A significant correlation (p<0.05 was found which shows that most of the aberrations do not appear randomly but are concentrated in sites rich in transposable elements.

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

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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. Copyright © 2016 Elsevier Ltd. All rights reserved.

The effect of high and low dissolved oxygen on the toxicity of oil sands coke and its leachate to Chironomus tentans

International Nuclear Information System (INIS)

Squires, A.J.; Liber, K.

2003-01-01

A study was conducted to assess the effect of low dissolved oxygen on the long-term leaching potential of the toxic constituents found in coke. Coke is one of the waste products produced during the oil sand upgrading process used at Syncrude Canada Ltd. and Suncor Energy Inc. Coke is contaminated by metals and organic compounds which can leach into the environment. In this study, coke from both companies was exposed to reconstituted water and high dissolved oxygen for a period of 30 days, during which time the overlying water containing the leachate and the coke pore-water was chemically analyzed. The benthic macroinvertebrate, Chironomus tentans, was exposed to the aged coke and the overlying leachate after the 30 day period. The study did not reveal any major difference in the survival or growth between the dissolved oxygen treatments or any of the leachate treatments. The macroinvertebrate in the aged Syncrude grew significantly while the Suncor coke strongly inhibited both survival and growth of the macroinvertebrate. The study demonstrates that coke has the potential to negatively affect benthic organisms if it is used uncovered in an aquatic reclamation effort

Chironomus riparius exposure to fullerene-contaminated sediment results in oxidative stress and may impact life cycle parameters

International Nuclear Information System (INIS)

Waissi, G.C.; Bold, S.; Pakarinen, K.; Akkanen, J.; Leppänen, M.T.; Petersen, E.J.; Kukkonen, J.V.K.

2017-01-01

Highlights: • FullerenesC_6_0 were tested to C. riparius with acute and chronic exposures. • The rapid uptake of fullerenes by C. riparius observed after an acute experiment. • Oxidative stress was localized in tissues under microvilli layer. - Abstract: A key component of understanding the potential environmental risks of fullerenes (C_6_0) is their potential effects on benthic invertebrates. Using the sediment dwelling invertebrate Chironomus riparius we explored the effects of acute (12 h and 24 h) and chronic (10 d, 15 d, and 28 d) exposures of sediment associated fullerenes. The aims of this study were to assess the impact of exposure to C_6_0 in the sediment top layer ((0.025, 0.18 and 0.48) C_6_0 mg/cm"2) on larval growth, oxidative stress and emergence rates and to quantify larval body burdens in similarly exposed organisms. Oxidative stress localization was observed in the tissues next to the microvilli and exoskeleton through a method for identifying oxidative stress reactions generated by reactive oxygen species. Rapid intake of fullerenes was shown in acute experiments, whereas body residues decreased after chronic exposure. Transmission electron microscopy analysis revealed oxidative damage and structural changes in cells located between the lipid droplets and next to the microvilli layer in fullerene exposed samples. Fullerene associated sediments also caused changes in the emergence rate of males and females, suggesting that the cellular interactions described above or other effects from the fullerenes may influence reproduction rates.

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

International Nuclear Information System (INIS)

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

2012-01-01

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.

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

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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.

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

International Nuclear Information System (INIS)

Planello, R.; Martinez-Guitarte, J.L.; Morcillo, G.

2007-01-01

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

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

DNA damage and transcriptional changes induced by tributyltin (TBT) after short in vivo exposures of Chironomus riparius (Diptera) larvae.

Science.gov (United States)

Morales, Mónica; Martínez-Paz, Pedro; Ozáez, Irene; Martínez-Guitarte, José Luis; Morcillo, Gloria

2013-08-01

Tributyltin (TBT) is a widespread environmental contaminant in aquatic systems whose adverse effects in development and reproduction are related to its well-known endocrine-disrupting activity. In this work, the early molecular effects of TBT in Chironomus riparius (Diptera) were evaluated by analyzing its DNA damaging potential and the transcriptional response of different endocrine-related genes. Twenty-four-hour in vivo exposures of the aquatic larvae, at environmentally relevant doses of TBT, revealed genotoxic activity as shown by significant increases in DNA strand breaks quantified with the comet assay. TBT was also able to induce significant increases in transcripts from the ecdysone receptor gene (EcR), the ultraspiracle gene (usp) (insect ortholog of the retinoid X receptor), the estrogen-related receptor (ERR) gene and the E74 early ecdysone-inducible gene, as measured by real-time RT-PCR. In contrast, the expression of the vitellogenin (vg) gene remained unaltered, while the hsp70 gene appeared to be down-regulated. The ability of TBT to up-regulate hormonal target genes provides the first evidence, at genomic level, of its endocrine disruptive effects and also suggests a mechanism of action that mimics ecdysteroid hormones in insects. These data reveal for the first time the early genomic effects of TBT on an insect genome. Copyright © 2013 Elsevier Inc. All rights reserved.

Rate of sediment intake by midge larvae (Chironomus plumosus: diptera) using a 134Cs tracer

International Nuclear Information System (INIS)

Gerking, S.D.; Berg, A.; Gerard, P.

1976-01-01

The food intake and assimilation of midge larvae (Chironomus plumosus) were determined by a 134 Cs technique which utilized the principle that the rate of excretion can be substituted for the rate of absorption when the larvae are in 134 Cs equilibrium with their environment. The larvae were introduced into contaminated sediments until they reached 134 Cs equilibrium. The time of reaching equilibrium and levels of radioactivity were the same at 10 and at 15 0 C (70 hr at a level of 1367 dpm/mg of larva) and were both significantly different from that at 20 0 C (40 hr at 1062 dpm/mg of larva). Cesium-134 elimination was followed on equilibrated larvae for as long as 330 hr. One egestion compartment (fast) and two excretion (medium and slow) compartments could be recognized at the three experimental temperatures. The loss rates from the second and third compartments at 10 0 C were slower and stretched out over longer time periods compared with those at 15 0 C, while the loss rate from the first compartment was much more comparable at the two temperatures. The first and second compartments merged at 20 0 C, while the slow compartment rose to almost three times that at 15 0 C. The food intake was nearly the same at the three temperatures (0.0986, 0.0893 and 0.0876 mg dry sediment/mg of larva/day). Thus, the larvae relied on an increase in assimilation to meet increased metabolic requirements at higher temperatures rather than depending upon a higher food intake. The gross growth efficiencies varied with temperature from 9.9 percent at 10 0 C to 15.1 percent at 15 0 C

Chironomus riparius exposure to fullerene-contaminated sediment results in oxidative stress and may impact life cycle parameters

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Waissi, G.C., E-mail: greta.waissi@uef.fi [Department of Environmental and Biological Sciences, University of Eastern Finland, Joensuu (Finland); Bold, S. [GEOMAR Helmholtz Centre of Ocean for Research Kiel (Germany); Pakarinen, K.; Akkanen, J. [Department of Environmental and Biological Sciences, University of Eastern Finland, Joensuu (Finland); Leppänen, M.T. [Finnish Environment Institute, Jyväskylä (Finland); Petersen, E.J. [Material Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, MD (United States); Kukkonen, J.V.K. [University of Jyväskylä, Department of Biological and Environmental Science, Jyväskylä (Finland)

2017-01-15

Highlights: • FullerenesC{sub 60} were tested to C. riparius with acute and chronic exposures. • The rapid uptake of fullerenes by C. riparius observed after an acute experiment. • Oxidative stress was localized in tissues under microvilli layer. - Abstract: A key component of understanding the potential environmental risks of fullerenes (C{sub 60}) is their potential effects on benthic invertebrates. Using the sediment dwelling invertebrate Chironomus riparius we explored the effects of acute (12 h and 24 h) and chronic (10 d, 15 d, and 28 d) exposures of sediment associated fullerenes. The aims of this study were to assess the impact of exposure to C{sub 60} in the sediment top layer ((0.025, 0.18 and 0.48) C{sub 60} mg/cm{sup 2}) on larval growth, oxidative stress and emergence rates and to quantify larval body burdens in similarly exposed organisms. Oxidative stress localization was observed in the tissues next to the microvilli and exoskeleton through a method for identifying oxidative stress reactions generated by reactive oxygen species. Rapid intake of fullerenes was shown in acute experiments, whereas body residues decreased after chronic exposure. Transmission electron microscopy analysis revealed oxidative damage and structural changes in cells located between the lipid droplets and next to the microvilli layer in fullerene exposed samples. Fullerene associated sediments also caused changes in the emergence rate of males and females, suggesting that the cellular interactions described above or other effects from the fullerenes may influence reproduction rates.

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.

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.

Vinclozolin alters the expression of hormonal and stress genes in the midge Chironomus riparius.

Science.gov (United States)

Aquilino, Mónica; Sánchez-Argüello, Paloma; Martínez-Guitarte, José-Luis

2016-05-01

Vinclozolin is a fungicide used in agriculture that can reach aquatic ecosystems and affect the organisms living there. Its effects have been intensively studied in vertebrates, where it acts as an antiandrogen, but there is a lack of information about its mechanistic effects on invertebrates. In this work, we analyzed the response of genes related to the endocrine system, the stress response, and the detoxification mechanisms of Chironomus riparius fourth instar larvae after 24h and 48h exposures to 20 (69.9nM), 200 (699nM), and 2000μg/L (6.99μM) of Vinclozolin. Survival analysis showed that this compound has low toxicity, as it was not lethal for this organism at the concentrations used. However, this fungicide was shown to modify the transcriptional activity of the ecdysone response pathway genes EcR, E74, and Kr-h1 by increasing their mRNA levels. While no changes were observed in disembodied, a gene related with the ecdysone synthesis metabolic pathway, Cyp18A1, which is involved in the inactivation of the active form of ecdysone, was upregulated. Additionally, the expression of two genes related to other hormones, FOXO and MAPR, did not show any changes when Vinclozolin was present. The analysis of stress response genes showed significant changes in the mRNA levels of Hsp70, Hsp24, and Gp93, indicating that Vinclozolin activates the cellular stress mechanisms. Finally, the expressions of the genes Cyp4G and GstD3, which encode enzymes involved in phase I and phase II detoxification, respectively, were analyzed. It was found that their mRNA levels were altered by Vinclozolin, suggesting their involvement in the degradation of this compound. For the first time, these results show evidence that Vinclozolin can modulate gene expression, leading to possible significant endocrine alterations of the insect endocrine system. These results also offer new clues about the mode of action of this compound in invertebrates. Copyright © 2016 Elsevier B.V. All rights

Beyond Intellectual Property: Toward Traditional Resource Rights ...

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That voice belongs to the world's indigenous peoples, and it is voice that has ... how indigenous peoples and local communities worldwide should approach ... National Council for Science and Technology at the Goeldi Museum, Belém, Brazil.

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

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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.

Ultraviolet filters and heat shock proteins: effects in Chironomus riparius by benzophenone-3 and 4-methylbenzylidene camphor.

Science.gov (United States)

Martín-Folgar, Raquel; Aquilino, Mónica; Ozáez, Irene; Martínez-Guitarte, José-Luis

2018-01-01

Benzophenone-3 (BP3) and 4-methylbenzylidene camphor (4MBC) are common ultraviolet filters (UV filters), compounds considered as emergent contaminants, used in different products like plastics and personal care products. The levels of these compounds are rising in the wild, but the effects they have on invertebrates are poorly understood. Chironomus riparius is a benthic insect widely used in toxicology, and several studies have been previously performed in our laboratory to determine the effects these compounds have on this organism at the molecular level. We have shown that UV filters can alter the mRNA levels of heat shock protein 70 (Hsp70), one of the most studied heat shock proteins. Although these proteins are crucial for the survival of organisms, little data is available on the effects these emergent contaminants have on them, especially in invertebrates. Here, we analyzed the transcriptional activity of 12 genes covering the different groups of heat shock protein [Hsp10, Hsp17, Hsp21, Hsp22, Hsp23, Hsp24, Hsp27, Hsp34, Hsp40, Hsp60, Hsc70 (3), and Hsc70 (4)] in response to 0.1 and 1 mg/L concentrations of BP3 and 4MBC at 8 and 24 h. The results showed that some small Hsp (sHsp) genes were altered by these compounds, while the genes of proteins present in mitochondria, Hsp10 and Hsp60, did not change. sHsps are also involved in developmental processes, so the observed variations could be due to the endocrine disruption activity described for these compounds rather than to a stress response.

Alteration in the expression of antioxidant and detoxification genes in Chironomus riparius exposed to zinc oxide nanoparticles.

Science.gov (United States)

Gopalakrishnan Nair, Prakash M; Chung, Ill Min

2015-12-01

Zinc oxide nanoparticles (ZnONPs) are widely used in several commercial products due to their unique physicochemical properties. However, their release into the aquatic environments through various anthropogenic activities will lead to toxic effect in aquatic organisms. Although several investigations have been reported on the effect of ZnONPs in aquatic organisms using traditional end points such as survival, growth, and reproduction, the molecular level end points are faster and sensitive. In this study, the expression of different genes involved in oxidative stress response, detoxification, and cellular defense was studied in an ecotoxicologically important bio-monitoring organism Chironomus riparius in order to understand the subcellular effects of ZnONPs. The fourth instar larvae were exposed to 0, 0.2, 2, 10, and 20 mg/L of ZnONPs and Zn ions (in the form of ZnSO4.7H2O) for 24 and 48 h period. The expression of CuZn superoxide dismutase, manganese superoxide dismutase, catalase, phospholipid hydroperoxide glutathione peroxidase, thioredoxin reductase 1 and delta-3, sigma-4 and epsilon-1 classes of glutathione S-transferases, cytochrome p4509AT2, and heat shock protein 70 were studied using real-time polymerase chain reaction method. Gene expression results showed that the expression of genes related to oxidative stress response was more pronounced as a result of ZnONPs exposure as compared to Zn ions. The mRNA expression of genes involved in detoxification and cellular protection was also modulated. Significantly higher expression levels of oxidative stress-related genes shows that oxidative stress is an important mechanism of toxicity as a result of ZnONPs exposure in C. riparius. Copyright © 2015 Elsevier Inc. All rights reserved.

Characterization of six small HSP genes from Chironomus riparius (Diptera, Chironomidae): Differential expression under conditions of normal growth and heat-induced stress.

Science.gov (United States)

Martín-Folgar, Raquel; de la Fuente, Mercedes; Morcillo, Gloria; Martínez-Guitarte, José-Luis

2015-10-01

Small heat shock proteins (sHSPs) comprise the most numerous, structurally diverse, and functionally uncharacterized family of heat shock proteins. Several Hsp genes (Hsp 90, 70, 40, and 27) from the insect Chironomus riparius are widely used in aquatic toxicology as biomarkers for environmental toxins. Here, we conducted a comparative study and characterized secondary structure of the six newly identified sHsp genes Hsp17, Hsp21, Hsp22, Hsp23, Hsp24, and Hsp34. A characteristic α-crystallin domain is predicted in all the new proteins. Phylogenetic analysis suggests a strong relation to other sHSPs from insects and interesting evidence regarding evolutionary origin and duplication events. Comparative analysis of transcription profiles for Hsp27, Hsp70, and the six newly identified genes revealed that Hsp17, Hsp21, and Hsp22 are constitutively expressed under normal conditions, while under two different heat shock conditions these genes are either not activated or are even repressed (Hsp22). In contrast, Hsp23, Hsp24, and Hsp34 are significantly activated along with Hsp27 and Hsp70 during heat stress. These results strongly suggest functional differentiation within the small HSP subfamily and provide new data to help understand the coping mechanisms induced by stressful environmental stimuli. Copyright © 2015 Elsevier Inc. All rights reserved.

Functional and structural rearrangements of salivary gland polytene chromosomes of Chironomus riparius Mg. (Diptera,Chironomidae) in response to freshly neutralized aluminium

Energy Technology Data Exchange (ETDEWEB)

Michailova, P.; Ilkova, J.; White, K.N

2003-05-01

Aluminium impacts on aquatic biota can be detected using polytene chromosomes as bio-markers - Although recent work has shown that environmentally relevant concentrations of freshly neutralized aluminium (AI) are bioavailable and toxic to freshwater invertebrates, the genotoxicity of Al has not been examined. Here we show that freshly neutralized Al affects structure and function of the salivary gland polytene chromosomes of the ubiquitous chironomid larva Chironomus riparius over three generations. Exposure to 500 {mu}g l{sup -1} added Al for 24-25 days resulted in a significantly higher frequency of numerous somatic aberrations, while no structural aberrations were found in F1 controls and few in the second and third generation. Aberrations also included deletions of sections of chromosome G of C. riparius larvae as well as deletions of one or more Balbiani rings. Changes in functional activity included decreased activity of the Balbiani rings (BR), and an increase in the number of decondensed centromeres. The activity of the nucleolar organizer (NOR) significantly decreased in F1 chironomids exposed to Al, while in the F2 and F3 generations the NOR showed normal (high) activity. First generation chironomids were generally more susceptible to Al although no clear evidence of tolerance was apparent over three generations. The possible use of alterations in chironomid polytene chromosomes as biomarkers of trace metal pollution is discussed.

Functional and structural rearrangements of salivary gland polytene chromosomes of Chironomus riparius Mg. (Diptera,Chironomidae) in response to freshly neutralized aluminium

International Nuclear Information System (INIS)

Michailova, P.; Ilkova, J.; White, K.N.

2003-01-01

Aluminium impacts on aquatic biota can be detected using polytene chromosomes as bio-markers - Although recent work has shown that environmentally relevant concentrations of freshly neutralized aluminium (AI) are bioavailable and toxic to freshwater invertebrates, the genotoxicity of Al has not been examined. Here we show that freshly neutralized Al affects structure and function of the salivary gland polytene chromosomes of the ubiquitous chironomid larva Chironomus riparius over three generations. Exposure to 500 μg l -1 added Al for 24-25 days resulted in a significantly higher frequency of numerous somatic aberrations, while no structural aberrations were found in F1 controls and few in the second and third generation. Aberrations also included deletions of sections of chromosome G of C. riparius larvae as well as deletions of one or more Balbiani rings. Changes in functional activity included decreased activity of the Balbiani rings (BR), and an increase in the number of decondensed centromeres. The activity of the nucleolar organizer (NOR) significantly decreased in F1 chironomids exposed to Al, while in the F2 and F3 generations the NOR showed normal (high) activity. First generation chironomids were generally more susceptible to Al although no clear evidence of tolerance was apparent over three generations. The possible use of alterations in chironomid polytene chromosomes as biomarkers of trace metal pollution is discussed

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

Science.gov (United States)

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

2015-01-01

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

Characterization of cholinesterases in Chironomus riparius and the effects of three herbicides on chlorpyrifos toxicity.

Science.gov (United States)

Pérez, Joanne; Monteiro, Marta S; Quintaneiro, Carla; Soares, Amadeu M V M; Loureiro, Susana

2013-11-15

In this study, the toxicities of four pesticides (the herbicides atrazine, terbuthylazine, metolachlor and the insecticide chlorpyrifos) previously detected in the Alqueva reservoir/dam (south of Portugal) were evaluated individually and in binary combinations of the herbicides and the insecticide using fourth-instar larvae of the aquatic midge Chironomus riparius. Chlorpyrifos induced toxicity to midges in all the 48 h toxicity bioassays performed. The swimming behaviour of the larvae was impaired, with EC50 values ranging from 0.15 to 0.17 μg/L. However, neither s-triazine (atrazine and terbuthylazine) herbicides nor metolachlor alone at concentrations up to 200 μg/L caused significant toxicity to C. riparius. When combined with both s-triazine herbicides, chlorpyrifos toxicity was enhanced by approximately 2-fold when tested in a binary mixture experimental setup, at the 50% effective concentration levels. To evaluate how chlorpyrifos toxicity was being increased, the cholinesterases (ChE) were characterized biochemically using different substrates and selective inhibitors. The results obtained suggested that the main enzyme present in this species is acetylcholinesterase (AChE) and therefore it was assayed upon C. riparius exposures to all pesticides individually and as binary mixtures. Although atrazine and terbuthylazine are not effective inhibitors of AChE, the potentiation of chlorpyrifos toxicity by the two s-triazine herbicides was associated with a potentiation in the inhibition of AChE in midges; both s-triazine herbicides at 200 μg/L increased the inhibition of the AChE activity by 7 and 8-fold, respectively. A strong correlation was observed between swimming behaviour disturbances of larvae and the inhibition of the AChE activity. In contrast, metolachlor did not affect chlorpyrifos toxicity at any of the concentrations tested. Therefore, the herbicides atrazine and terbuthylazine can act as synergists in the presence of chlorpyrifos, increasing

Genotoxic effects of environmental endocrine disruptors on the aquatic insect Chironomus riparius evaluated using the comet assay.

Science.gov (United States)

Martínez-Paz, Pedro; Morales, Mónica; Martínez-Guitarte, José Luis; Morcillo, Gloria

2013-12-12

Genotoxicity is one of the most important toxic endpoints in chemical toxicity testing and environmental risk assessment. The aim of this study was to evaluate the genotoxic potential of various environmental pollutants frequently found in aquatic environments and characterized by their endocrine disrupting activity. Monitoring of DNA damage was undertaken after in vivo exposures of the aquatic larvae of the midge Chironomus riparius, a model organism that represents an abundant and ecologically relevant macroinvertebrate, widely used in freshwater toxicology. DNA-induced damage, resulting in DNA fragmentation, was quantified by the comet assay after short (24 h) and long (96 h) exposures to different concentrations of the selected toxicants: bisphenol A (BPA), nonylphenol (NP), pentachlorophenol (PCP), tributyltin (TBT) and triclosan (TCS). All five compounds were found to have genotoxic activity as demonstrated by significant increases in all the comet parameters (%DNA in tail, tail length, tail moment and Olive tail moment) at all tested concentrations. Persistent exposure did not increase the extent of DNA damage, except for TCS at the highest concentration, but generally there was a reduction in DNA damage thought to be associated with the induction of the detoxification processes and repairing mechanisms. Comparative analysis showed differences in the genotoxic potential between the chemicals, as well as significant time and concentration-dependent variations, which most likely reflect differences in the ability to repair DNA damage under the different treatments. The present report demonstrates the sensitivity of the benthic larvae of C. riparius to these environmental genotoxins suggesting its potential as biomonitor organism in freshwater ecosystems. The results obtained about the DNA-damaging potential of these environmental pollutants reinforce the need for additional studies on the genotoxicity of endocrine active substances that, by linking genotoxic

Can chronic exposure to imidacloprid, clothianidin, and thiamethoxam mixtures exert greater than additive toxicity in Chironomus dilutus?

Science.gov (United States)

Maloney, E M; Morrissey, C A; Headley, J V; Peru, K M; Liber, K

2018-07-30

Widespread agricultural use of neonicotinoid insecticides has resulted in frequent detection of mixtures of these compounds in global surface waters. Recent evidence suggests that neonicotinoid mixtures can elicit synergistic toxicity in aquatic insects under acute exposure conditions, however this has not been validated for longer exposures more commonly encountered in the environment. Therefore, we aimed to characterize the chronic (28-day) toxicity of imidacloprid, clothianidin, and thiamethoxam mixtures under different doses and mixture ratios to determine if the assumption of synergistic toxicity would hold under more environmentally realistic exposure settings. The sensitive aquatic insect Chironomus dilutus was used as a representative test species, and successful emergence was used as a chronic endpoint. Applying the MIXTOX modeling approach, predictive parametric models were fitted using single-compound toxicity data and statistically compared to observed toxicity in subsequent mixture tests. Imidacloprid-clothianidin, clothianidin-thiamethoxam and imidacloprid-clothianidin-thiamethoxam mixtures did not significantly deviate from concentration-additive toxicity. However, the cumulative toxicity of the imidacloprid-thiamethoxam mixture deviated from the concentration-additive reference model, displaying dose-ratio dependent synergism and resulting in up to a 10% greater reduction in emergence from that predicted by concentration addition. Furthermore, exposure to select neonicotinoid mixtures above 1.0 toxic unit tended to shift sex-ratios toward more male-dominated populations. Results indicate that, similar to acute exposures, the general assumption of joint additivity cannot adequately describe chronic cumulative toxicity of all neonicotinoid mixtures. Indeed, our observations of weak synergism and sex-ratio shifts elicited by some mixture combinations should be considered in water quality guideline development and environmental risk assessment practices

Nucleolar organizer (NO) size as a measure of instantaneous growth in Chironomus riparius larvae (Diptera: Chironomidae) : a tool for monitoring individual and population responses to stress

Energy Technology Data Exchange (ETDEWEB)

Martin, J.P.; Ciborowski, J.J.; Wytrykush, C. [Windsor Univ., Windsor, ON (Canada)

2009-07-01

This presentation reported on 2 laboratory experiments that were conducted using Chironomus riparius larvae to relate nucleolar growth (NO) size to chironomid growth. In one experiment, 5 treatments varied in diet quality only, which was manipulated by providing midge larvae with 1.0 mg of food per individual per day, but varying the ratio of Tetramin to non-nutritious methyl-cellulose. A second experiment followed a 2 x 2 factorial design. The factors were growth period and diet quality. Diet quality and growth period were found to influence the individual biomass considerably. NO size was related to the quality of the diet provided at the end of the experiment, regardless of larval biomass. Therefore, NO size appears to be related to growth rate at time of collection rather than larval size. The authors proposed using NO size of larvae in natural populations as a measure of growth on which to base estimates of secondary production and as a new way to monitor individual and population responses to environmental stress. Preliminary field measurements of larval production and NO size from oil sands-affected and reference wetlands were found to be consistent with laboratory results.

Nucleolar organizer (NO) size as a measure of instantaneous growth in Chironomus riparius larvae (Diptera: Chironomidae) : a tool for monitoring individual and population responses to stress

International Nuclear Information System (INIS)

Martin, J.P.; Ciborowski, J.J.; Wytrykush, C.

2009-01-01

This presentation reported on 2 laboratory experiments that were conducted using Chironomus riparius larvae to relate nucleolar growth (NO) size to chironomid growth. In one experiment, 5 treatments varied in diet quality only, which was manipulated by providing midge larvae with 1.0 mg of food per individual per day, but varying the ratio of Tetramin to non-nutritious methyl-cellulose. A second experiment followed a 2 x 2 factorial design. The factors were growth period and diet quality. Diet quality and growth period were found to influence the individual biomass considerably. NO size was related to the quality of the diet provided at the end of the experiment, regardless of larval biomass. Therefore, NO size appears to be related to growth rate at time of collection rather than larval size. The authors proposed using NO size of larvae in natural populations as a measure of growth on which to base estimates of secondary production and as a new way to monitor individual and population responses to environmental stress. Preliminary field measurements of larval production and NO size from oil sands-affected and reference wetlands were found to be consistent with laboratory results.

800 years of mining activity and 450 years of geological research in the Krušné Hory/Erzgebirge Mountains, Central Europe

Czech Academy of Sciences Publication Activity Database

Breiter, Karel

2014-01-01

Roč. 9, č. 1 (2014), s. 105-134 ISSN 1807-5401 Institutional support: RVO:67985831 Keywords : Krušné hory/Erzgebirge * mining * history * granite Subject RIV: DB - Geology ; Mineralogy http://www.museu-goeldi.br/editora/bn/artigos/cnv9n1_2014/800(breiter).pdf

Comparison of gene expression profiles in the aquatic midge (Chironomus tentans) larvae exposed to two major agricultural pesticides.

Science.gov (United States)

Tang, Guanghui; Yao, Jianxiu; Zhang, Xin; Lu, Nanyan; Zhu, Kun Yan

2018-03-01

We developed a high-resolution expression microarray based on 2456 unique transcripts from a cDNA library of the aquatic midge (Chironomus tentans). By using the microarray, we detected that 146, 434 and 243 genes were differentially expressed after C. tentans larvae were exposed to chlorpyrifos (organophosphate insecticide) at 0.1 and 0.5 μg/L, and atrazine (triazine herbicide) at 1000 μg/L, respectively, for 48 h. The number of differentially expressed genes in the larvae exposed to chlorpyrifos at 0.5 μg/L was three times of that in the larvae exposed to chlorpyrifos at 0.1 μg/L. Among the differentially expressed genes in response to chlorpyrifos exposures, 76 genes showed significant Blast hits, and among them 42 were in common between the chlorpyrifos and atrazine exposures. In 19 differentially expressed xenobiotic detoxification genes, 16 were significantly up-regulated in the larvae exposed to chlorpyrifos and/or atrazine. Two cytochrome P450 genes (CtCYP6EV1 and CtCYP4DG2) were specifically up-regulated by chlorpyrifos, whereas three cytochrome P450 genes (CtCYP4DG1, CtCYP6EX3 and CtCYP6EV3) were specifically up-regulated by atrazine. Our results showed that chlorpyrifos exposures even at low concentrations can lead to significant changes in gene expression. The significant transcriptional responses are likely attributed to larval intoxication by the insecticide. These results not only support our previous studies in which candidate gene approaches were used, but also can potentially help develop specific molecular markers for monitoring pesticide exposures in non-target organisms in aquatic systems. Copyright © 2017 Elsevier Ltd. All rights reserved.

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.

Comparative chronic toxicity of imidacloprid, clothianidin, and thiamethoxam to Chironomus dilutus and estimation of toxic equivalency factors.

Science.gov (United States)

Cavallaro, Michael C; Morrissey, Christy A; Headley, John V; Peru, Kerry M; Liber, Karsten

2017-02-01

Nontarget aquatic insects are susceptible to chronic neonicotinoid insecticide exposure during the early stages of development from repeated runoff events and prolonged persistence of these chemicals. Investigations on the chronic toxicity of neonicotinoids to aquatic invertebrates have been limited to a few species and under different laboratory conditions that often preclude direct comparisons of the relative toxicity of different compounds. In the present study, full life-cycle toxicity tests using Chironomus dilutus were performed to compare the toxicity of 3 commonly used neonicotinoids: imidacloprid, clothianidin, and thiamethoxam. Test conditions followed a static-renewal exposure protocol in which lethal and sublethal endpoints were assessed on days 14 and 40. Reduced emergence success, advanced emergence timing, and male-biased sex ratios were sensitive responses to low-level neonicotinoid exposure. The 14-d median lethal concentrations for imidacloprid, clothianidin, and thiamethoxam were 1.52 μg/L, 2.41 μg/L, and 23.60 μg/L, respectively. The 40-d median effect concentrations (emergence) for imidacloprid, clothianidin, and thiamethoxam were 0.39 μg/L, 0.28 μg/L, and 4.13 μg/L, respectively. Toxic equivalence relative to imidacloprid was estimated through a 3-point response average of equivalencies calculated at 20%, 50%, and 90% lethal and effect concentrations. Relative to imidacloprid (toxic equivalency factor [TEF] = 1.0), chronic (lethality) 14-d TEFs for clothianidin and thiamethoxam were 1.05 and 0.14, respectively, and chronic (emergence inhibition) 40-d TEFs were 1.62 and 0.11, respectively. These population-relevant endpoints and TEFs suggest that imidacloprid and clothianidin exert comparable chronic toxicity to C. dilutus, whereas thiamethoxam induced comparable effects only at concentrations an order of magnitude higher. However, the authors caution that under field conditions, thiamethoxam readily degrades to

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. Copyright © 2016 Elsevier B.V. All rights reserved.

Micro x-ray absorption spectroscopic analysis of arsenic localization and biotransformation in Chironomus riparius Meigen (Diptera: Chironomidae) and Culex tarsalis Coquillett (Culicidae)

International Nuclear Information System (INIS)

Mogren, Christina L.; Webb, Samuel M.; Walton, William E.; Trumble, John T.

2013-01-01

The distribution and speciation of arsenic (As) were analyzed in individuals of various life stages of a midge, Chironomus riparius, and the mosquito Culex tarsalis exposed to 1000 μg/l arsenate. X-ray absorption spectroscopy (XAS) revealed that C. riparius larvae accumulate As in their midgut, with inorganic arsenate [As(V)] being the predominant form, followed by arsenite [As(III)] and an As-thiol. Reduced concentrations of As in pupal and adult stages of C. riparius indicate excretion of As between the larval and pupal stages. In adults, As was limited to the thorax, and the predominant form was an As-thiol. In Cx. tarsalis, As was not found in high enough concentrations to determine As speciation, but the element was distributed throughout the larva. In adults, As was concentrated in the thorax and eyes of adults. These results have implications for understanding the biotransformation of As and its movement from aquatic to terrestrial environments. -- Highlights: •C. riparius larvae reduced arsenate to arsenite in the midgut. •C. riparius larvae accumulated As in the midgut, with 27% as a transformed As-thiol. •C. riparius adults retained As in the thorax, with 53% as As-thiol. •Larvae of Cx. tarsalis did not have a specific site of As accumulation. •Low concentrations of As in adults suggest reduced terrestrial transfer potential. -- Arsenic accumulation and biotransformation in aquatic insects is variable, but the location and speciation of As provides insight into the detoxification mechanisms of aquatic Diptera

Assessing the effects of fluoxetine on Physa acuta (Gastropoda, Pulmonata) and Chironomus riparius (Insecta, Diptera) using a two-species water-sediment test

Energy Technology Data Exchange (ETDEWEB)

Sanchez-Argueello, Paloma [Laboratory for Ecotoxicology, Department of the Environment, INIA, Crta, A Coruna km 7, 28040 Madrid (Spain)], E-mail: arguello@inia.es; Fernandez, Carlos; Tarazona, Jose V. [Laboratory for Ecotoxicology, Department of the Environment, INIA, Crta, A Coruna km 7, 28040 Madrid (Spain)

2009-03-01

Fluoxetine has been tested in a two-species water-sediment system, which allowed a two-generation study with Chironomus riparius and a partial life-cycle with the freshwater snail Physa acuta to be performed at the same time. The design considered the continuous application of fluoxetine to overlaying water for nominal concentrations of 31.25, 62.5, 125 and 250 {mu}g/L. A fifth treatment (87.5 {mu}g/L) level consisted of pulse applications once a week. Measures of water and sediment concentrations were determined once a week and at the end of experiment (day 44), respectively. The fate study demonstrated that water dissipation can be explained by partitioning of fluoxetine to sediment. At the end of experiment, the percentage of detected fluoxetine was up to 10-fold higher in sediment than in overlaying water. The employed two-species test allowed distinguishing, in the same exposure conditions, effects due to waterborne exposure together ingestion at the sediment surface (freshwater grazing snail P. acuta) and exposure by burrowing activities (sediment-dwelling insect larvae C. riparius). The effect assessment showed a stimulation of P. acuta reproduction at lower concentrations (31.25 and 62.5 {mu}g/L), while the opposite effect was observed at the highest treatment (250 {mu}g/L). Additional studies should be conducted to establish if the statistically significant differences observed in F0 sex ratio at the 62.5 {mu}g/L and F1 adult emergence at 31.25 {mu}g/L of C. riparius have a toxicological significance. This study showed that fluoxetine can affect reproduction of freshwater molluscs. The results of the present study may contribute to knowledge on ecotoxicology of pharmaceuticals, about which little data is available. The possible consequences and implications for targeting the environmental risk assessment of fluoxetine are discussed.

Assessing the effects of fluoxetine on Physa acuta (Gastropoda, Pulmonata) and Chironomus riparius (Insecta, Diptera) using a two-species water-sediment test

International Nuclear Information System (INIS)

Sanchez-Argueello, Paloma; Fernandez, Carlos; Tarazona, Jose V.

2009-01-01

Fluoxetine has been tested in a two-species water-sediment system, which allowed a two-generation study with Chironomus riparius and a partial life-cycle with the freshwater snail Physa acuta to be performed at the same time. The design considered the continuous application of fluoxetine to overlaying water for nominal concentrations of 31.25, 62.5, 125 and 250 μg/L. A fifth treatment (87.5 μg/L) level consisted of pulse applications once a week. Measures of water and sediment concentrations were determined once a week and at the end of experiment (day 44), respectively. The fate study demonstrated that water dissipation can be explained by partitioning of fluoxetine to sediment. At the end of experiment, the percentage of detected fluoxetine was up to 10-fold higher in sediment than in overlaying water. The employed two-species test allowed distinguishing, in the same exposure conditions, effects due to waterborne exposure together ingestion at the sediment surface (freshwater grazing snail P. acuta) and exposure by burrowing activities (sediment-dwelling insect larvae C. riparius). The effect assessment showed a stimulation of P. acuta reproduction at lower concentrations (31.25 and 62.5 μg/L), while the opposite effect was observed at the highest treatment (250 μg/L). Additional studies should be conducted to establish if the statistically significant differences observed in F0 sex ratio at the 62.5 μg/L and F1 adult emergence at 31.25 μg/L of C. riparius have a toxicological significance. This study showed that fluoxetine can affect reproduction of freshwater molluscs. The results of the present study may contribute to knowledge on ecotoxicology of pharmaceuticals, about which little data is available. The possible consequences and implications for targeting the environmental risk assessment of fluoxetine are discussed

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

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Gizelle Amora

2015-07-01

Full Text Available 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 Tokunaga and Chironomus striatipennis Kieffer, both with distributions restricted to Asia. The objectives of this study were to provide morphological information on this Chironomus population, to investigate its identity using DNA barcoding and, to provide bionomic information about this species. Chironomus DNA barcode data were obtained from GenBank and Barcode of Life Data Systems (BOLD and, together with our data, were analyzed using the neighbor-joining method with 1000 bootstrap replicates and the genetic distances were estimated using the Kimura-2-parameter. At the morphological level, the Brazilian population cannot be distinguished either from C. striatipennis or C. kiiensis, configuring a species complex but, at the molecular level our studied population is placed in a clade together with C. striatipennis, from South Korea. Bionomic characteristics of the Brazilian Chironomus population differ from the ones of C. kiiensis from Japan, the only species in this species complex with bionomic information available. The Brazilian Chironomus population has a smaller size, the double of the number of eggs and inhabits oligotrophic water, in artificial container. In the molecular analysis, populations of C. striatipennis and C. kiiensis are placed in a clade, formed by two groups: Group A (which includes populations from both named species, from different Asiatic regions and our Brazilian population and Group B (with populations of C. kiiensis from Japan and South Korea

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

International Nuclear Information System (INIS)

Long, Sara M.; Tull, Dedreia L.; Jeppe, Katherine J.; De Souza, David P.; Dayalan, Saravanan; Pettigrove, Vincent J.; McConville, Malcolm J.; Hoffmann, Ary A.

2015-01-01

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

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

The contribution of Osvaldo Rodrigues da Cunha (1928-2011 to History of Science

Directory of Open Access Journals (Sweden)

Nelson Sanjad

2011-04-01

Full Text Available The article describes and analyzes the historiographical works of Brazilian Herpetologist Osvaldo Rodrigues da Cunha (1928-2011, researcher of Museu Paraense Emilio Goeldi. It presents his published works, mainly in the field of History of Science, in which he studied the institution he belonged to and the scientists who lived in Amazonia. Cunha's complete works dedicated to the theme, composed along of almost 50 years, are reported in the paper.

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)

Planello, R.; Martinez-Guitarte, J.L.; Morcillo, G.

2010-01-01

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 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.

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.

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

International Nuclear Information System (INIS)

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

2006-01-01

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

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.

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

Science.gov (United States)

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

2013-01-01

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

Structure of the secondary xylem of Aniba Aubl. species from the Brazilian Amazon

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Cláudia Viana Urbinati

2014-09-01

Full Text Available The aim of this study was to characterize the wood of Aniba species from the Brazilian Amazon, on the basis of specimens in the wood collection of the Herbarium of the Museu Paraense Emílio Goeldi, in the city of Belém, Brazil. The species were found to present a homogeneous structure in the secondary xylem, as defined by the location of oil cells; the presence of tyloses and crystals; and singularities of the radial and axial parenchyma.

Social and Environmental Responsibility and Local Sustainable Development: The Case of the Environmental Education Project and Asset – PEAP

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Eugênia Rosa Cabral

2015-04-01

Full Text Available The study analyzes the actions of social responsibility expressed by the Environmental and Heritage Education Project (PEAP, which has been  implemented in the Boa Vista and Moura communities, both located in Oriximiná, State of Pará. This project purported to promote the rescue and preservation of environmental and cultural heritage in local communities, developed in a partnership between the Museu Paraense Emilio Goeldi (Emilio Goeldi [a painter] Pará Museum] (MPEG, the private company Mineração Rio do Norte (Rio do Norte Mining (MRN and representatives of local communities. This study examines to what extent the actions of PEAP can be considered drivers of sustainable local development. To answer this question, the research focused on the implementation of the PEAP actions and their effects on the two communities under study. Specifically, we sought to identify potential social, cultural and economic impacts of the actions of PEAP on both communities, and to identify future expectations of social subjects involved. This is a case study that follows a qualitative approach. The data collected in documents and interviews were analyzed according to the concepts of sustainable local development, corporate social responsibility and tri-sector partnership. The study identified that the actions taken by the PEAP result of management practices and participatory social planning, and reflecting the redemption of traditional practices, socialization of information and income generation, which together contribute to sustainable local development.

The BPA-substitute bisphenol S alters the transcription of genes related to endocrine, stress response and biotransformation pathways in the aquatic midge Chironomus riparius (Diptera, Chironomidae).

Science.gov (United States)

Herrero, Óscar; Aquilino, Mónica; Sánchez-Argüello, Paloma; Planelló, Rosario

2018-01-01

Bisphenol S (BPS) is an industrial alternative to the endocrine disruptor bisphenol A (BPA), and can be found in many products labeled "BPA-free". Its use has grown in recent years, and presently it is considered a ubiquitous emerging pollutant. To date there is a lack of information on the effects of BPS on invertebrates, although they represent more than 95% of known species in the animal kingdom and are crucial for the structure and proper function of ecosystems. In this study, real-time RT-PCR was used to determine the early detrimental effects of BPS on the transcriptional rate of genes in the model species Chironomus riparius, specifically those related to the ecdysone pathway (EcR, ERR, E74, Vtg, cyp18a1) crucial for insect development and metamorphosis, stress and biotransformation mechanisms (hsp70, hsp40, cyp4g, GPx, GSTd3) that regulate adaptive responses and determine survival, and ribosome biogenesis (its2, rpL4, rpL13) which is essential for protein synthesis and homeostasis. While 24-hour exposure to 0.5, 5, 50, and 500 μg/L BPS had no effect on larval survival, almost all the studied genes were upregulated following a non-monotonic dose-response curve. Genes with the greatest increases in transcriptional activity (fold change relative to control) were EcR (3.8), ERR (2), E74 (2.4), cyp18a1 (2.5), hsp70 (1.7), hsp40 (2.5), cyp4g (6.4), GPx (1.8), and GST (2.1), while others including Vtg, GAPDH, and selected ribosomal genes remained stable. We also measured the transcriptional activity of these genes 24 hours after BPS withdrawal and a general downregulation compared to controls was observed, though not significant in most cases. Our findings showed that BPS exposure altered the transcriptional profile of these genes, which may have consequences for the hormone system and several metabolic pathways. Although further research is needed to elucidate its mode of action, these results raise new concerns about the safety of BPA alternatives.

Effects of in vivo exposure to UV filters (4-MBC, OMC, BP-3, 4-HB, OC, OD-PABA) on endocrine signaling genes in the insect Chironomus riparius.

Science.gov (United States)

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

2013-07-01

There is increasing evidence indicating that several UV filters might have endocrine disruptive effects. Numerous studies have evaluated hormonal effects in vertebrates, mainly reporting estrogenic and androgenic activities in mammals and fishes. There is only limited knowledge about potential endocrine activity in invertebrate hormonal systems. In this work, the effects on endocrine signaling genes of six frequently used UV filters were investigated in Chironomus riparius, a reference organism in aquatic toxicology. The UV filters studied were: octyl-p-methoxycinnamate (OMC) also called 2-ethylhexyl-4-methoxycinnamate (EHMC); 4-methylbenzylidene camphor (4-MBC); benzophenone-3 (BP-3); 4-hidroxybenzophenone (4-HB); octocrylene (OC); and octyldimethyl-p-aminobenzoate (OD-PABA). After in vivo exposure at different dosages, expression levels of the genes coding for the ecdysone receptor (EcR), the ultraspiracle (usp, ortholog of the RXR) and the estrogen-related receptor (ERR) were quantified by Real Time PCR. The EcR gene was significantly upregulated by 4-MBC, OMC/EHMC and OD-PABA, with a dose-related response following 24h exposure. In contrast, the benzophenones, BP-3 and 4-HB, as well as OC did not alter this gene at the same exposure conditions. The transcription profiles of the usp and ERR genes were not significantly affected, except for BP-3 that inhibited the usp gene at the highest concentration. To our knowledge, this is the first experimental evidence in invertebrates of a direct effect of UV filters on endocrine-related genes, and is consistent with the known effects on vertebrate hormonal receptor genes. The capability of 4-MBC, OMC/EHMC and OD-PABA to stimulate the expression of the ecdysone receptor, a key transcription factor for the ecdysone-genomic response in arthropods, suggests the possibility of a broad and long-term effect on this hormonal pathway. These findings strengthen the need for further research about the ecotoxicological implications

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

Science.gov (United States)

Macedo, Lilian Cristina; Melo, Francisco Tiago de Vasconcelos; Ávila-Pires, Teresa Cristina Sauer; Giese, Elane Guerreiro; dos Santos, Jeannie Nascimento

2016-01-01

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.

The BPA-substitute bisphenol S alters the transcription of genes related to endocrine, stress response and biotransformation pathways in the aquatic midge Chironomus riparius (Diptera, Chironomidae.

Directory of Open Access Journals (Sweden)

Óscar Herrero

Full Text Available Bisphenol S (BPS is an industrial alternative to the endocrine disruptor bisphenol A (BPA, and can be found in many products labeled "BPA-free". Its use has grown in recent years, and presently it is considered a ubiquitous emerging pollutant. To date there is a lack of information on the effects of BPS on invertebrates, although they represent more than 95% of known species in the animal kingdom and are crucial for the structure and proper function of ecosystems. In this study, real-time RT-PCR was used to determine the early detrimental effects of BPS on the transcriptional rate of genes in the model species Chironomus riparius, specifically those related to the ecdysone pathway (EcR, ERR, E74, Vtg, cyp18a1 crucial for insect development and metamorphosis, stress and biotransformation mechanisms (hsp70, hsp40, cyp4g, GPx, GSTd3 that regulate adaptive responses and determine survival, and ribosome biogenesis (its2, rpL4, rpL13 which is essential for protein synthesis and homeostasis. While 24-hour exposure to 0.5, 5, 50, and 500 μg/L BPS had no effect on larval survival, almost all the studied genes were upregulated following a non-monotonic dose-response curve. Genes with the greatest increases in transcriptional activity (fold change relative to control were EcR (3.8, ERR (2, E74 (2.4, cyp18a1 (2.5, hsp70 (1.7, hsp40 (2.5, cyp4g (6.4, GPx (1.8, and GST (2.1, while others including Vtg, GAPDH, and selected ribosomal genes remained stable. We also measured the transcriptional activity of these genes 24 hours after BPS withdrawal and a general downregulation compared to controls was observed, though not significant in most cases. Our findings showed that BPS exposure altered the transcriptional profile of these genes, which may have consequences for the hormone system and several metabolic pathways. Although further research is needed to elucidate its mode of action, these results raise new concerns about the safety of BPA alternatives.

Mouthpart deformities in Chironomidae (Diptera) as bioindicators of heavy metals pollution in Shiroro Lake, Niger State, Nigeria.

Science.gov (United States)

Arimoro, Francis O; Auta, Yohanna I; Odume, Oghenekaro N; Keke, Unique N; Mohammed, Adamu Z

2018-03-01

In this study, mouthpart deformities in Chironomid larvae (Diptera) were investigated in relation to sediment contamination in the Shiroro Lake in Nigeria. Metals and chironomids were sampled monthly at three stations (A-C) between August 2013 and January 2014. Across the stations, zinc ranged (3.9-75mg/g), manganese (1.29-1.65mg/g), lead (0.00-0.10mg/g), iron (101-168mg/g) and copper (0.13-0.17mg/g). The metal ions did not differ significantly (P > 0.05) between the sampling stations. However, zinc and iron ions were significantly different between the sampling seasons (P < 0.05). Thirteen chironomid species were recorded, with Chironomus sp., Polypedilum sp. and Ablabesmyia sp. dominating the assemblage structure. Mouthpart deformities were significantly higher at Station A compared with Station C, and seasonally significantly higher during dry season compared with wet season. Elevated incidences of deformity were recorded in Chironomus spp larvae as compared to other genera therefore for further studies in this region assessments should be based solely on Chironomus species and ignoring the rest. Strategies need to be developed to reduce the contaminations and the biological effects. Copyright © 2017 Elsevier Inc. All rights reserved.

Effects of cadmium on life-cycle parameters in a multi-generation study with Chironomus riparius following a pre-exposure of populations to two different tributyltin concentrations for several generations.

Science.gov (United States)

Vogt, Christian; Hess, Maren; Nowak, Carsten; Diogo, João Barateiro; Oehlmann, Jörg; Oetken, Matthias

2010-10-01

So far only a few studies have been performed to assess the effects of dynamic pollutant exposure on life-history parameters of invertebrates. In a previous multi-generation approach with the midge Chironomus riparius we tested if a chronic tributyltin pre-exposure alters the ability of a population to cope with subsequent cadmium stress. In the experiment two separate chironomid populations were exposed via sediments to different TBT-concentrations (4.46 and 8.93 μg Sn/kg dw) for several generations, followed by subsequent cadmium exposure (1.2 mg Cd/kg dw) for three generations. While the TBT-exposure to 4.46 μg Sn/kg dw had only small effects on the development and reproduction of C. riparius the higher TBT-concentration of 8.93 μg Sn/kg dw led to negative effects on life-history traits. Therefore, a higher adverse effect of the higher TBT-concentration and thus a higher susceptibility to other stressors could be assumed. Within, this paper only the results of the second stressor experiment were presented; clear effects of Cd on development and reproduction of C. riparius were determined independent of the pre-exposure scenario. While no differences in Cd-sensitivity were found between the population without pre-exposure to TBT and the population pre-exposed to the low TBT-concentration (4.46 μg Sn/kg dw), the pre-exposure of midges to the higher TBT-concentration (8.93 μg Sn/kg dw) resulted in a significantly higher susceptibility to subsequent Cd-stress. These results document that the exposure history may influence the reaction to altered chemical stress. Our findings are relevant to understand and predict the evolutionary fate of populations in rapidly changing, human-impacted environments. However, the fact that chemical-induced reduced genetic diversity, which is not necessarily linked to genetic adaptation, leads to a reduced fitness under altered stress conditions, is to our knowledge a novel finding.

Fulltext PDF

Indian Academy of Sciences (India)

Protective effects of sodium orthovanadate in diabetic reticu- locytes and ageing ... 235. Biomolecules. Physical aspect of microscopic behaviour of biomolecules ... Chironomus. Extracellular electrical activity from the photoreceptors of midge.

Histone H1 heterogeneity in the midge, Chironomus thummi. Structural comparison of the H1 variants in an organism where their intrachromosomal localization is possible.

Science.gov (United States)

Hoyer-Fender, S; Grossbach, U

1988-09-01

1. Seven subfractions of histone H1 have been isolated and purified from larvae of Chironomus thummi (Diptera). They have been denominated I-1, II-1, II-2, II-3, III-1, III-2, and III-3, according to the order of migration in two steps of preparative electrophoresis. 2. The amino acid compositions are similar to those of other H1 histones. Subfractions I-1 and II-1 were found to contain one methionine and two tyrosine residues, II-2 contained two methionine and three tyrosine residues, and III-1 one methionine and three tyrosine residues. The other subfractions contained one or two methionine and two or three tyrosine residues. For subfractions I-1 and II-1 a chain length of about 252 amino acids was estimated. 3. Peptide pattern analyses after chemical cleavage at the methionine and tyrosine residues, and enzymatic cleavage with thrombin and chymotrypsin, respectively, showed that all subfractions have different individual primary structures. A comparison of peptide sizes and of the positions in the peptide patterns of epitopes recognized by monoclonal antibodies was made to check whether some of the subfractions could arise by proteolytic degradation of others. This possibility can be excluded for five of the subfractions and is very improbable for the two others. Treatment of C. thummi H1 with alkaline phosphatase did not change the pattern of subfractions, while the phosphorylated subfraction of histone H2A disappeared after this treatment. Most and very probably all subfractions are thus H1 sequence variants. 4. Inbred strains and individual larvae of C. thummi were found to comprise all seven variants. The H1 heterogeneity can therefore not be due to allelic polymorphism. Salivary gland nuclei were found to contain variant I-1 and at least some of the other variants. 5. H1 from Drosophila melanogaster and from calf thymus were used as reference molecules in all cleavage experiments and yielded the peptide patterns expected from the sequence. The comparison

Conversações desassossegadas: diálogos sobre coleções etnográficas com o povo indígena Ka’apor

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Claudia Leonor López Garcés

Full Text Available Resumo Este artigo trata do processo de diálogo sobre coleções etnográficas de objetos Ka’apor e da curadoria compartilhada da exposição “A Festa do Cauim”, atividades promovidas pelo Museu Nacional de Etnologia de Leiden (NME, Holanda, junto ao Museu Paraense Emílio Goeldi (MPEG, Brasil, e o povo indígena Ka’apor da Terra Indígena Alto Turiaçu, localizada no estado de Maranhão, na Amazônia brasileira. É reflexo de uma mudança de filosofia no NME em direção a uma atividade mais inclusiva e colaborativa, como também dos processos de atuação com povos indígenas promovidos no Museu Goeldi e da necessidade política dos Ka’apor de chamar atenção, em nível nacional e internacional, para a defesa de seus direitos territoriais, continuamente ameaçados por atores envolvidos com a exploração ilegal de madeira no seu território. Considerando diferentes enfoques disciplinares, principalmente da antropologia e da museologia, em consonância com o pensamento indígena, assim como com as negociações de interesses e encontro de diversas perspectivas cognitivas e posicionamentos políticos, este artigo, além de documentar e refletir sobre a produção cocriativa de uma exposição etnográfica, procura repensar as dimensões cognitiva, política e ética deste tipo de trabalho com povos indígenas.

Comparing the impacts of sediment-bound bifenthrin on aquatic macroinvertebrates in laboratory bioassays and field microcosms.

Science.gov (United States)

Boyle, Rhianna L; Hoak, Molly N; Pettigrove, Vincent J; Hoffmann, Ary A; Long, Sara M

2016-11-01

We conducted two laboratory bioassays and two field microcosm exposures with bifenthrin (a synthetic pyrethroid) in order to evaluate the capacity of single-species laboratory bioassays to predict lethal and sublethal impacts on aquatic invertebrates in microcosms. For the laboratory species, Chironomus tepperi, larval survival was reduced by 24% at 53.66µg/g OC, while adult emergence was reduced at concentrations of 33.33µg/g OC and higher, with a 61% decrease at 77.78µg/g OC and no emergence at 126.67µg/g OC. The abundance of several other microcosm taxa was reduced in the microcosms at a similar concentration range (33.33µg/g OC and above), however there was no impact on the abundance of the congeneric species, Chironomus oppositus. The differences in impacts between test systems were potentially due to both differing species sensitivity and the interaction of ambient temperature with bifenthrin toxicity. Bifenthrin also was associated with early emergence of Chironomus sp. in both test systems, at concentrations of 10µg/g OC and higher (laboratory) and 43.90µg/g OC (microcosm), and with a significant decrease in the proportion of C. oppositus males in a microcosm. These findings indicate that while laboratory bioassays accurately predict many impacts in the field, there are some limitations to the predictive capacity of these tests. Copyright © 2016 Elsevier Inc. All rights reserved.

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 Chironomus). The choice of test endpoint and statistical analysis influenced 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.

Extracellular electrical activity from the photoreceptors of midge

Indian Academy of Sciences (India)

Unknown

349. Keywords. Chironomus; electroretinogram; insect development; midge; photoreceptor ... ceran insects, only larval ocelli of mosquito (Family: Culi- cidae) have been ... and Ball (1995) studied the influence of light in Chiro- nomus tentans ...

Making “Uirapuru”: a musical quest in the Brazilian Rain Forest

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Sam Zebba

2010-04-01

Full Text Available Sixty years ago the author, an Israeli film student at the University of California, Los Angeles, set out to make a film based on a Brazilian Indian legend which had been set to music by Heitor Villa-Lobos (1887-1959. Filming was carried out among Urubú-Ka’apor Indians in the state of Maranhão. In Belém, capital of Pará, he was joined by German anthropologist Peter Paul Hilbert (1914-1989 of the Goeldi Museum on an adventurous and creative expedition, culminating in a prize-winning art-documentary film and a life-long friendship between the two.

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

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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.

Application of Tritiated Compounds to the Midge Chironomus and some Aspects of the Metabolism of Salivary Gland Chromosomes; Emploi de Composes Trities pour l'Etude du Chironome et de Certains Aspects du Metabolisme des Chromosomes des Glandes Salivaires; 041f 0440 0438 043c 0414 ; Aplicacion de Compuestos Tritiados a la Mosca Cbironomus y Algunos Aspectos del Metabolismo en los Cromosomas de las Glandulas Salivares

Energy Technology Data Exchange (ETDEWEB)

Pelling, C. [Max-Planck-Institut fuer Biologie, Tuebingen, Federal Republic of Germany (Germany)

1962-02-15

The investigations were carried out on the salivary gland chromosomes of Chironomus tentons. Tritiated compounds (H{sup 3}-thymidine, H{sup 3}-uridine, H{sup 3}-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) [French] Les recherches ont porte sur les chromosomes des glandes salivaires du chironomus tentans. On a injecte les composes trities (thymidine, uridine, acides amines) dans l'hemolymphe de la larve en vue de determiner le lieu d'incorporation dans les chromosomes geants. Apres fixation par les glandes salivaires, on a procede a des autoradiographies de preparations broyees. Ces autoradiographies montrent que ce sont les chromosomes geants qui permettent le mieux de localiser,- avec une forte resolution, l'activite au niveau chromosomique. L'auteur a pu suivre la synthese de l'ADN (thymidine), la synthese de l'ARN (uridine) et la synthese des proteines a l'interieur de la cellule en determinant le temps et le taux approximatif d'incorporation. A l'inverse de la synthese des proteines, la synthese de l'ADN et celle de l'ARN sont limitees aux chromosomes. L'activite physiologique essentielle

Chromatin Structure in Bands and Interbands of Polytene Chromosomes Imaged by Atomic Force Microscopy

NARCIS (Netherlands)

de Grauw, C.J.; de Grauw, C.J.; Avogadro, A.; van den Heuvel, D.J.; van den Heuvel, D.J.; van der Werf, Kees; Otto, Cornelis; Kraan, Yvonne M.; van Hulst, N.F.; Greve, Jan

1998-01-01

Polytene chromosomes from Drosophila melanogaster, observed from squash preparations, and chromosomes from Chironomus thummi thummi, investigated under physiological conditions, are imaged using an Atomic Force Microscope. Various chromatin fiber structures can be observed with high detail in fixed

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,...

Aggressive keloid-mimicking tumor in Melanosuchus niger in captivity

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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.

Zoobenthic fauna and seasonal changes of mamasin dam lake ...

African Journals Online (AJOL)

STORAGESEVER

2009-09-15

Sep 15, 2009 ... Psammoryctides deserticula (Grimm, 1877). 14. Procladius (Holotanypus) sp. 15. Chironomus plumosus (Linnaeus, 1758). 16. C. anthracinus (Zetterstedt, 1860). Insecta. Chironomidae. 17. Polypedilum nubeculosum (Meigen, 1804). Figure 2. Average numbers (BS/m2) of chironomidae, oligochaeta and ...

Diversity of the chironomidae (diptera) of river Niger related to water ...

African Journals Online (AJOL)

Organic pollution and nutrients loading were the main factors explaining the differences in spatial distribution. Some taxa, e.g. Chironomus gr. plumosus and Microchironomus sp. are positively correlated to those factors, while others as Tanytarsini, Nilodosis sp., Micropelopinae and Procladius sp. are negatively correlated.

Journal of Genetics | Indian Academy of Sciences

Indian Academy of Sciences (India)

Sibling species are widespread among the dipteran insects and as such are well studied because some species are important medically (mosquitoes), genetically (Drosophila) and cytologically(Sciara and Chironomus). The well-studied classical pairs of sibling species in Drosophila are: D. pseudoobscura and D. persimilis ...

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

Fate and effects of esfenvalerate in agricultural ponds

DEFF Research Database (Denmark)

Samsøe-Petersen, L.; Gutavson, K.; Madsen, T.

2001-01-01

in enclosures in a natural lake and in the laboratory on surface (Cymatia coleoptrata) and sediment (Chironomus riparius) insects. The latter were used in sediment-plus-water and in water-only tests, measuring effects on emergence and mortality. The measurements in the artificial pond indicated exposure...

Clarification of Einfeldia Kieffer, 1922 (Diptera: Chironomidae) with E. australiensis (Freeman, 1961), comb. n. based on immature stages.

Science.gov (United States)

Cranston, Peter S; Martin, Jon; Mulder, Monica; Spies, Martin

2016-08-31

The immature stages are described for the first time for Chironomus (Xenochironomus) australiensis Freeman (Diptera: Chironomidae) and the adult male is redescribed including from type specimens. The species does not belong to Chironomus Meigen or Xenochironomus Kieffer, but is best placed in a modestly expanded Einfeldia Kieffer. Application of this genus name is clarified, including by a lectotype fixation for its type species, E. pectoralis Kieffer, 1924. Einfeldia australiensis (Freeman) comb. n. provides the first record of the genus from Australia; otherwise the genus is reported confidently only from North America, Central America and western Europe to Japan. The immature stages of E. australiensis occur in relatively shallow mesotrophic to eutrophic dune lakes and maars with circum-neutral pH and high conductivity, from southeastern Queensland to southern Australia. The cytology is described briefly from larval salivary glands. Alternative genus placements for the species are discussed, and problems with Einfeldia and connected systematics in the tribe Chironomini are addressed.

Food preference of red devil (Amphilophus labiatus) in the Sermo Reservoir, Kulon Progo Regency

Science.gov (United States)

Ariasari, A.; Helmiati, S.; Setyobudi, E.

2018-03-01

Food preference is one of the important information that can be used to know the food chain in order to manage fisheries resources. This study aims to determine the food habits and preference of red devil (Amphilophus labiatus) in the Sermo Reservoir, Kulon Progo Regency. Samples were collected randomly each month from September 2013 to February 2014. Each sample collected was measured its total length, body weight, and determined sex, then dissected to measure the gut length and to observe gut contents. Results showed that red devil is omnivorous (relative gut length = 3.83) with food composition consisted of fish, crustaceans, detritus, phytoplankton, zooplankton, plants, insects, insect’s larvae, Chironomus sp., and annelids. A change occurred in the food preference of red devil, i.e. the young fish prefers to feed Chironomus sp. larvae (86.02 %) whereas the adult fish prefers fish/fish chunk (81.82 %). Trophic level status of red devil showed as carnivorous and niche overlapping between male and female of the adult.

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

NARCIS (Netherlands)

de Haas, 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

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

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Miriam Junghans

2008-01-01

Full Text Available 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, até agora, poucos exemplos da atuação feminina no campo das ciências naturais antes da fundação das universidades na década de 1930. A análise da trajetória de Emilia Snethlage, articulando questões de história das mulheres e o estudo das formas de inserção da cientista em redes institucionais e sociais, poderá contribuir para o melhor entendimento de campos historiográficos pouco percorridos.The German ornithologist Emilia Snethlage (1868-1929 spent her scientific career in Brazil, working at the Museu Paraense Emilio Goeldi in the state of Pará and at the Museu Nacional in Rio de Janeiro. One of the highlights of her scientific work was her catalog of Amazonian birds, published in 1914. Another was her travels by foot through the unknown regions between the Xingu and Tapajós rivers in 1909, accompanied solely by Indian guides. To date, the historiography of the sciences in Brazil has provided few examples of female engagement in the field of the natural sciences prior to establishment of universities in the 1930s. Conjoining issues in women's history with the study of the roles played by this female scientist in institutional and social networks, this analysis of Emília Snethlage's career can help us better understand little explored fields of historiography.

Consumption, indigeneous knowledge and cultural values of the ...

African Journals Online (AJOL)

Of the edible insects, lakeflies (Chaoborus and Chironomus sp) are least documented as items of human consumption. They are eaten by the Luo communities living within the Lake Victoria basin. The purpose of this study was to evaluate the importance of lake flies as a source of food and its role in cultural practices.

Rapid genetic erosion in pollutant-exposed experimental chironomid populations

Energy Technology Data Exchange (ETDEWEB)

Nowak, Carsten [Abteilung Okologie und Evolution, Institut fuer Okologie, Evolution und Diversitaet, J. W. Goethe-Universitaet Frankfurt am Main, Siesmayerstrasse 70, 60054 Frankfurt am Main (Germany)], E-mail: cnowak@senckenberg.de; Vogt, Christian [Abteilung Aquatische Okotoxikologie, Institut fuer Okologie, Evolution und Diversitaet, J. W. Goethe-Universitaet Frankfurt am Main, Siesmayerstrasse 70, 60054 Frankfurt am Main (Germany)], E-mail: vogt@bio.uni-frankfurt.de; Pfenninger, Markus [Abteilung Okologie und Evolution, Institut fuer Okologie, Evolution und Diversitaet, J. W. Goethe-Universitaet Frankfurt am Main, Siesmayerstrasse 70, 60054 Frankfurt am Main (Germany)], E-mail: pfenninger@bio.uni-frankfurt.de; Schwenk, Klaus [Abteilung Okologie und Evolution, Institut fuer Okologie, Evolution und Diversitaet, J. W. Goethe-Universitaet Frankfurt am Main, Siesmayerstrasse 70, 60054 Frankfurt am Main (Germany)], E-mail: k.schwenk@bio.uni-frankfurt.de; Oehlmann, Joerg [Abteilung Aquatische Okotoxikologie, Institut fuer Okologie, Evolution und Diversitaet, J. W. Goethe-Universitaet Frankfurt am Main, Siesmayerstrasse 70, 60054 Frankfurt am Main (Germany)], E-mail: oehlmann@bio.uni-frankfurt.de; Streit, Bruno [Abteilung Okologie und Evolution, Institut fuer Okologie, Evolution und Diversitaet, J. W. Goethe-Universitaet Frankfurt am Main, Siesmayerstrasse 70, 60054 Frankfurt am Main (Germany)], E-mail: streit@bio.uni-frankfurt.de; Oetken, Matthias [Abteilung Aquatische Okotoxikologie, Institut fuer Okologie, Evolution und Diversitaet, J. W. Goethe-Universitaet Frankfurt am Main, Siesmayerstrasse 70, 60054 Frankfurt am Main (Germany)], E-mail: oetken@bio.uni-frankfurt.de

2009-03-15

Few studies have evaluated how effectively environmental contamination may reduce genetic diversity of a population. Here, we chose a laboratory approach in order to test if tributyltin (TBT) exposure at environmentally relevant concentrations leads to reduced genetic variation in the midge Chironomus riparius. Two TBT-exposed and two unexposed experimental populations were reared simultaneously in the laboratory for 12 generations. We recorded several life-history traits in each generation and monitored genetic variation over time using five variable microsatellite markers. TBT-exposed strains showed increased larval mortality (treatments: 43.8%; controls: 27.8%), slightly reduced reproductive output, and delayed larval development. Reduction of genetic variation was strongest and only significant in the TBT-exposed strains (treatments: -45.9%, controls: -24.4% of initial heterozygosity) after 12 generations. Our findings document that chemical pollution may lead to a rapid decrease in genetic diversity, which has important implications for conservation strategies and ecological management in polluted environments. - Chronic TBT exposure reduces allelic variation at five variable microsatellite loci in experimental populations of Chironomus riparius.

Rapid genetic erosion in pollutant-exposed experimental chironomid populations

International Nuclear Information System (INIS)

Nowak, Carsten; Vogt, Christian; Pfenninger, Markus; Schwenk, Klaus; Oehlmann, Joerg; Streit, Bruno; Oetken, Matthias

2009-01-01

Few studies have evaluated how effectively environmental contamination may reduce genetic diversity of a population. Here, we chose a laboratory approach in order to test if tributyltin (TBT) exposure at environmentally relevant concentrations leads to reduced genetic variation in the midge Chironomus riparius. Two TBT-exposed and two unexposed experimental populations were reared simultaneously in the laboratory for 12 generations. We recorded several life-history traits in each generation and monitored genetic variation over time using five variable microsatellite markers. TBT-exposed strains showed increased larval mortality (treatments: 43.8%; controls: 27.8%), slightly reduced reproductive output, and delayed larval development. Reduction of genetic variation was strongest and only significant in the TBT-exposed strains (treatments: -45.9%, controls: -24.4% of initial heterozygosity) after 12 generations. Our findings document that chemical pollution may lead to a rapid decrease in genetic diversity, which has important implications for conservation strategies and ecological management in polluted environments. - Chronic TBT exposure reduces allelic variation at five variable microsatellite loci in experimental populations of Chironomus riparius

A new subterranean species of Phreatobius Goeldi, 1905 (Siluriformes, Incertae sedis from the Southwestern Amazon basin

Directory of Open Access Journals (Sweden)

Oscar Akio Shibatta

2007-01-01

Full Text Available A new species of the previously monotypic catfish genus Phreatobius is described from an artificial well in the village of Rio Pardo, located 90 km south of the city of Porto Velho, State of Rondônia, Brazil, in the drainage area of the Rio Branco (Rio Madeira system, Amazon basin. Phreatobius dracunculus n. sp. differs from its only congener, P. cisternarum, by the absence of eyes (vs. present, the lack of dark integumentary pigmentation (vs. faint dark pigment always present, the presence of five pectoral-fin rays (vs. four, ventral procurrent rays 11-13 (vs. 22 to 26, dorsal procurrent rays 29-31 (vs. 42 to 50, fewer vertebrae (52 or 53 vs. 59 to 64 and the larger pseudotympanus. The new species shows all diagnostic characters so far proposed for Phreatobius, including an unusual red coloration in life. The localities of the two species of Phreatobius are approximately 1900 km apart. That, in association with their peculiar and mostly inaccessible habitats, indicates that the genus may be widely distributed in the Amazon basin.Uma nova espécie do gênero previamente monotípico Phreatobius é descrita de um poço artificial no Povoado de Rio Pardo, localizado 90 km ao sul da cidade de Porto Velho, Estado de Rondônia, Brasil, na área de drenagem do rio Branco (sistema do Rio Madeira, bacia Amazônica. Phreatobius dracunculus sp. n. difere da única espécie congênere, P. cisternarum, pela ausência de olhos (vs. presente, ausência de pigmentação na pele (vs. algum pigmento escuro sempre presente, presença de cinco raios na nadadeira peitoral (vs. 4, menor número de raios procorrentes ventrais 11-13 (vs. 22 a 26, e menor número de raios procorrentes dorsais 29-31 (vs. 42 a 50, menor número de vértebras (52 ou 53 vs. 59 a 64 e pseudotímpano maior. A nova espécie apresenta todos os caracteres diagnósticos propostos para Phreatobius, incluindo a conspícua coloração vermelha em vida. As localidades das duas espécies de Phreatobius estão aproximadamente a 1900 km de distância. A presença desta espécie em região tão distante da ocorrência de P. cisternarum em associação com o ambiente freático peculiar, evidenciam que o grupo pode estar amplamente distribuído na bacia amazônica.

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

Directory of Open Access Journals (Sweden)

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.

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

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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.

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...

Fate of ethinylestradiol in the aquatic environment and the associated effects on organisms of different trophic levels

OpenAIRE

Maes, Hanna

2011-01-01

The accumulation kinetics of an important, highly effective, and persistent xeno-estrogen, 17alpha-ethinylestradiol (EE2), in the aquatic environment were investigated in indicator species representing the different trophic levels of an ecosystem: a primary producer (Desmodesmus suspicatus), a primary consumer of the water phase (Daphnia magna) and one of the sediment (Chironomus riparius), and a secondary consumer (Danio rerio). Algae highly concentrated 14C-EE2 (72 h Calgae/Cwater: 2200 L/k...

Naturally Occurring Culturable Aerobic Gut Flora of Adult Phlebotomus papatasi, Vector of Leishmania major in the Old World

Science.gov (United States)

2012-05-22

bioremediation [80,81] Lysinibacillus boronitolerans1 soil [82] Oceanobacillus sp.1 Chironomus sp. [83] fermented food [84] Terribacillus saccharophilus1 soil [85...traditional Korean fermented food. J Microbiol 48: 862–866. 85. An S-Y, Asahara M, Goto K, Kasai H, Yokota A (2007) Terribacillus saccharophilus gen. nov...wild strains of Psoroptes ovis infesting sheep. Parasitology 123: 441–446. 111. Cousin FJ, Mater DDG, Foligne B, Jan G (2011) Dairy Propionibacteria

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

Science.gov (United States)

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

1996-01-01

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

Cytogenetic study of natural chironomini (diptera, chiromedae) populations from open water bodies of former Semipalatinsk test site

International Nuclear Information System (INIS)

Seysebaev, A.T.; Rakhimbaeva, K. T.; Bakhtin, M.M.

2002-01-01

In the paper genetic variability of natural population of chironomidae inhabiting in waters on the territory of Semipalatinsk test site (STS) is studied. Ten Chironomini species of Chironomidae subfamily and one species of Tanypodinae subfamily were identified using cyto-taxonomic methods of analysis. Cytophotomap of polythene chromosomes of salivary glands were established for four species: Glyptotendipes salinus, Captochironomus setivalva, Camptochriomonus tentas and Chironomus plumosus. For the first time a new previously unknown species of Chironomus gender, and namely C, genelenus 1. sp. n. was described and a cytophotomap of its polythene chromosomes was established. A detailed quantative and qualitative analysis of chromosome polymorphism was carried out and the spectrum and frequency of the disk sequences and genotypic combination were identified. New evidence on change in the polythene chromosomes structure were revealed in certain Chironomini species dwelling in the radioactively contaminated water bodies of STS: rare, unique disk sequences of chromosomes were found, a series of specific homo zygote and heterozygote inversions were observed, which evidently resulted from long-term adaptive selection under conditions of the chronic ionizing radiation. Increase of in frequency of structural mutations of chromosomes was found in mitotic cells of imago disk of Chironomini larvae is revealed. This increase indicates that at the STS many population of benthos organisms are directly affected by the ionizing radiation

Two genes in Balbiani ring 2 with metabolically different 75S transcripts

OpenAIRE

Galler, R.; Saiga, H.; Widmer, R. M.; Lezzi, M.; Edström, J.-E.

1985-01-01

Balbiani ring 2 (BR2) in salivary glands of Chironomus pallidivittatus and C. tentans (two sibling species of the subgenus Camptochironomus) is a favoured model system for studies of gene organization and transcript formation. Here we show that BR2 is more complex than hitherto believed, containing two 75S RNA-producing genes, BR2a and BR2b, present in different 35–40 kb blocks of DNA. The transcripts hybridizing to two different repeat units originating in BR2 differ in size. Further support...

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

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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.

Induction of mouthpart deformities in chironomid larvae exposed to contaminated sediments

Energy Technology Data Exchange (ETDEWEB)

Di Veroli, Alessandra [Dipartimento di Biologia Cellulare e Ambientale, Universita degli Studi di Perugia, Via Elce Di Sotto, 06123 Perugia (Italy); Goretti, Enzo [Dipartimento di Biologia Cellulare e Ambientale, Universita degli Studi di Perugia, Via Elce Di Sotto, 06123 Perugia (Italy); Paumen, Miriam Leon; Kraak, Michiel H.S.; Admiraal, Wim [Department of Aquatic Ecology and Ecotoxicology, Institute for Biodiversity and Ecosystem Dynamics (IBED), University of Amsterdam, Sciencepark 904, 1098 XH Amsterdam (Netherlands)

2012-07-15

The aim of the present study was to improve the cause-effect relationship between toxicant exposure and chironomid mouthpart deformities, by linking induction of mouthpart deformities to contaminated field sediments, metal mixtures and a mutagenic polycyclic aromatic compound metabolite (acridone). Mouthpart deformities in Chironomus riparius larvae were induced by both the heavy metal mixture and by acridone. A clear correlation between metal concentrations in the sediment and deformities incidence was only observed when the contaminated field sediments were left out of the analysis, probably because these natural sediments contained other toxic compounds, which could be responsible for a higher incidence of deformities than predicted by the measured metal concentrations only. The present study clearly improved the cause-effect relationship between toxicant exposure and the induction of mouthpart deformities. It is concluded that the incidence of mouthpart deformities may better reflect the potential toxicity of contaminated sediments than chemical analysis. - Highlights: Black-Right-Pointing-Pointer We tested the induction of deformities in C. riparius in laboratory toxicity experiments. Black-Right-Pointing-Pointer We used field sediments and spiked sediments with heavy metals and mutagenic PAC. Black-Right-Pointing-Pointer Mouthpart deformities were induced both by heavy metal mixtures and by acridone. Black-Right-Pointing-Pointer A correlation between metal concentrations in the sediment and deformities was found. Black-Right-Pointing-Pointer Mouthpart deformities better reflect the toxicity of sediments than chemical analysis. - Mouthpart deformities of Chironomus riparius larvae better reflect the toxicity of sediments than chemical analysis.

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

International Nuclear Information System (INIS)

Nazneen, S.; Begum, F.; Sharmeen, R.; Ahmed, Z.

2003-01-01

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)

Evaluation of long term effects of thermal effluents on stream biota

International Nuclear Information System (INIS)

Sublette, J.E.

1980-10-01

In order to evaluate the effects of energy related developments in aquatic ecosystems, a normal water data base must be established. One approach used is the selection of indicator communities on species with fairly well known environmental tolerances and requirements. The Chironomidae (Order Diptera) dominate the macrobenthic assemblages of many streams. The group offers great potential for water quality assessment. The studies in this report determine the species composition of Chironomidae at stream sites in New Mexico, across the relationship of species composition to water quality parameters, and map karyotypes for the chironomus decorus group

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

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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.

Leaf litter as a possible food source for chironomids (Diptera in Brazilian and Portuguese headwater streams Detritos foliares como possível fonte de alimento para Chironomidae (Diptera em riachos de cabeceira brasileiros e portugueses

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Marcos Callisto

2007-06-01

Full Text Available Our objective was to evaluate the potential use of leaf detritus by chironomid larvae. Field and laboratory experiments were performed using leaves and chironomid species collected in Portugal and Brazil. Laboratory experiments under controlled conditions were done using microbial conditioned senescent leaves of Alnus glutinosa (L. Gaertn, Neriumoleander L., Protium heptaphilum (Aubl. March, Protium brasiliense (Spreng Engl., Myrcia guyanensis(Aubl. DC and Miconia chartacea Triana. Laboratory experiments were performed using specimens collected from leaf litter in local streams. Whenever possible, after the experiments, chironomids were allowed to emerge as adults and identified. In Portugal the following taxa were identified: Micropsectra apposita (Walker, 1856, Polypedilum albicorne (Meigen, 1838,Eukiefferiella claripennis Lundbeck (1898, Rheocricotopus (Psilocricotopus atripes Rempel (1937 and Ablabesmyia Johannsen (1905 (Diptera, Chironomidae. Consumption rates ranged from 0.15 ± 0.10 mg (AFDM of leaf animal-1 day-1 (Micropsectra apposita feeding on Alnus glutinosa up to 0.85 ± 0.33 mg (AFDM of leaf animal-1 day-1 (Polypedilum albicorne feeding on Miconia chartacea. In Brazil, the following taxa were identified from leaves: Phaenopsectra sp., Chironomus spp. and Polypedilum sp. and maximum consumption rates reached 0.47 ± 0.28 (AFDM of leaf mg.animal-1.day-1 (Chironomus Meigen (1803 feeding on Protium heptaphilum. Feeding experiments with laboratory cultured specimens, revealed that some chironomids were unable to feed on decomposing leaves (e.g., C. xanthus Rempel (1939 on P.brasiliensis and M.guyanensis. Our results suggest that some stream chironomids (not typical shredders can use leaf litter of riparian vegetation as a complementary food source.O objetivo foi avaliar o potencial uso de detritos foliares por larvas de Chironomidae. Foram realizados experimentos em campo e em laboratório utilizando folhas e larvas de Chironomidae

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

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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

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

Science.gov (United States)

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

2013-01-01

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

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

Energy Technology Data Exchange (ETDEWEB)

Kumar, Amit, E-mail: amitk@barc.gov.in [Radiation Biology and Health Sciences Division, Bhabha Atomic Research Centre, Mumbai 400 085 (India); Ali, Manjoor [Radiation Biology and Health Sciences Division, Bhabha Atomic Research Centre, Mumbai 400 085 (India); Ningthoujam, Raghumani S. [Chemistry Division, Bhabha Atomic Research Centre, Mumbai 400 085 (India); Gaikwad, Pallavi [Department of Zoology, Savitribai Phule Pune University, Pune 411 007, Mumbai (India); Kumar, Mukesh [Solid State, Physics Division, Bhabha Atomic Research Centre, Mumbai 400 085 (India); Nath, Bimalendu B. [Department of Zoology, Savitribai Phule Pune University, Pune 411 007, Mumbai (India); Pandey, Badri N. [Radiation Biology and Health Sciences Division, Bhabha Atomic Research Centre, Mumbai 400 085 (India)

2016-04-15

Highlights: • The sites of Ln and An interaction in Hb depend upon their charge-to-ionic-radii ratio. • Th(IV), Ce(IV) and U(VI) altered structure and oxygen-binding of Hb. • Spectroscopic studies determined binding characteristics of actinides. • Metal–Hb interaction was tested in an environmentally-important aquatic midge, Chironomus. - Abstract: 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 75 μM, 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.

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

International Nuclear Information System (INIS)

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

2016-01-01

Highlights: • The sites of Ln and An interaction in Hb depend upon their charge-to-ionic-radii ratio. • Th(IV), Ce(IV) and U(VI) altered structure and oxygen-binding of Hb. • Spectroscopic studies determined binding characteristics of actinides. • Metal–Hb interaction was tested in an environmentally-important aquatic midge, Chironomus. - Abstract: 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 75 μM, 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.

Common antigenic determinants of haemoglobin as basis of immunological cross-reactivity between chironomid species (Diptera, Chironomidae): studies with human and animal sera.

Science.gov (United States)

Baur, X; Dewair, M; Haegele, K; Prelicz, H; Scholl, A; Tichy, H

1983-01-01

Chironomids, of which approximately 10,000 species exist, are reported to cause severe immediate type allergic diseases in man. In the present study, immunological cross-reactivity between 14 chironomid species from different continents was proven by RAST inhibition, double immunodiffusion and a new allergoprint technique, based upon PAGE separation of insect crude extracts. Using isolated chironomid haemoglobins and sera of sensitized persons, as well as rabbit antibodies against larval crude extract or against the haemoglobin fraction of Chironomus thummi, it could be proven that cross-reactivity derives at least predominantly from haemoglobin components with common antigenic determinants in the different species. Images Fig. 2 Fig. 7 Fig. 8 Fig. 9 PMID:6197219

Benthic fauna of 41 acid sensitive headwater lakes in north central Ontario. [Chironomidae salinarius; Chironomidae anthracinus; Tanytarsini

Energy Technology Data Exchange (ETDEWEB)

Dermott, R.; Kelso, J.R.M.; Douglas, A.

1986-01-01

The benthic fauna of 41 nonhumic, soft water lakes situated north of lakes Superior and Huron were sampled during 1980. The pH range of the lakes sampled was 4.6 to 7.7. The benthic infauna displayed regional differences in abundance and composition, with large variation with each district. Total abundance, biomass, and number of taxa were not correlated with lake pH or alkalinity. The Chironomidae displayed a slight change in percent composition of the major species with lower pH. The Tanytarsini and Chironomus Salinarius group decreased, while C. anthracinus group increased in relative abundance in those lakes with lower pH. Other factors appear to control the distribution of the various invertebrate orders, with depth and sediment nature being important variables.

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

Science.gov (United States)

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

2014-11-01

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

Estimation of vanadium water quality benchmarks for the protection of aquatic life with relevance to the Athabasca Oil Sands region using species sensitivity distributions.

Science.gov (United States)

Schiffer, Stephanie; Liber, Karsten

2017-11-01

Elevated vanadium (V) concentrations in oil sands coke, which is produced and stored on site of some major Athabasca Oil Sands companies, could pose a risk to aquatic ecosystems in northern Alberta, Canada, depending on its future storage and utilization. In the present study, V toxicity was determined in reconstituted Athabasca River water to various freshwater organisms, including 2 midge species (Chironomus dilutus and Chironomus riparius; 4-d and 30-d to 40-d exposures) and 2 freshwater fish species (Oncorhynchus mykiss and Pimephales promelas; 4-d and 28-d exposures) to facilitate estimation of water quality benchmarks. The acute toxicity of V was 52.0 and 63.2 mg/L for C. dilutus and C. riparius, respectively, and 4.0 and 14.8 mg V/L for P. promelas and O. mykiss, respectively. Vanadium exposure significantly impaired adult emergence of C. dilutus and C. riparius at concentrations ≥16.7 (31.6% reduction) and 8.3 (18.0% reduction) mg/L, respectively. Chronic toxicity in fish presented as lethality, with chronic 28-d LC50s of 0.5 and 4.3 mg/L for P. promelas and O. mykiss, respectively. These data were combined with data from the peer-reviewed literature, and separate acute and chronic species sensitivity distributions (SSDs) were constructed. The acute and chronic hazardous concentrations endangering only 5% of species (HC5) were estimated as 0.64 and 0.05 mg V/L, respectively. These new data for V toxicity to aquatic organisms ensure that there are now adequate data available for regulatory agencies to develop appropriate water quality guidelines for use in the Athabasca Oil Sands region and elsewhere. Until then, the HC5 values presented in the present study could serve as interim benchmarks for the protection of aquatic life from exposure to hazardous levels of V in local aquatic environments. Environ Toxicol Chem 2017;36:3034-3044. © 2017 SETAC. © 2017 SETAC.

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

Nitrous Oxide Emission by Aquatic Macrofauna

DEFF Research Database (Denmark)

Stief, Peter; Nielsen, Lars Peter; Schramm, Andreas

-term metabolic induction of gut denitrification is the preferential production of nitrous oxide rather than dinitrogen. These observations were made in detailed studies on the larvae of the freshwater insects Chironomus plumosus and Ephemera danica which both can be very abundant in lake and stream sediments......, respectively. Aside from these case studies, we screened more than 20 macrofauna species in various aquatic habitats for nitrous oxide production. Filter- and deposit-feeders that ingest large quantities of microorganisms were the most important emitters of nitrous oxide. In contrast, predatory species that do...... not ingest large quantities of microorganisms produced insignificant amounts of nitrous oxide. With increasing eutrophication, filter- and deposit-feeders often become the dominant feeding guilds of benthic communities. Thus, with increasing nitrate pollution, aquatic macrofauna has the potential to further...

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

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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.

Nitrous Oxide Production by Abundant Benthic Macrofauna

DEFF Research Database (Denmark)

Stief, Peter; Schramm, Andreas

of the short-term metabolic induction of gut denitrification is the preferential production of nitrous oxide rather than dinitrogen. On a large scale, gut denitrification in, for instance, Chironomus plumosus larvae can increase the overall nitrous oxide emission of lake sediment by a factor of eight. We...... screened more than 20 macrofauna species for nitrous oxide production and identified filter-feeders and deposit-feeders that occur ubiquitously and at high abundance (e.g., chironomids, ephemeropterans, snails, and mussels) as the most important emitters of nitrous oxide. In contrast, predatory species...... that do not ingest large quantities of microorganisms produced insignificant amounts of nitrous oxide. Ephemera danica, a very abundant mayfly larva, was monitored monthly in a nitrate-polluted stream. Nitrous oxide production by this filter-feeder was highly dependent on nitrate availability...

Effects of low-level chronic irradiation on aquatic organisms

Energy Technology Data Exchange (ETDEWEB)

Etoh, H. (National Inst. of Radiological Sciences, Chiba (Japan))

1980-10-01

Effects of continual irradiation for a long term on fishes and aquatic invertebrates were outlined. Effects of low-level chronic irradiation on aquatic organisms were less than acute effects induced when the same dose was irradiated once. The radiosensitivity of the genital organ to continual irradiation was high. There was a difference in radiosensitivity of the genital organ between female and male, and the degree of the difference varied according to kinds of animals. In an experiment on continual irradiation of adult killifishes, ova recovered from radiation damage, but spermatozoa did not recover. Incubation rates of eggs obtained from aquatic organisms which lived in water where radioactive sewage flowed into decreased significantly, and the frequency of reverse position of salivary gland chromosomes which were peculiar to exposed organisms increased in larvae of Chironomus tentans.

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

NARCIS (Netherlands)

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

2012-01-01

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

60Co accumulation from sediment and planktonic algae by midge larvae (Chironomus luridus)

International Nuclear Information System (INIS)

Baudin, J.P.; Nucho, R.

1992-01-01

This paper reports the results of several experiments carried out to evaluate uptake and retention by a limicolous midge larva of 60 Co retained in sediment, either adsorbed on mineral particles or bound to planktonic algae. In order to determine their relative contributions in radionuclide accumulation, the different vectors (water, algae and sediment) were first labelled individually and then simultaneously. 60 Co accumulation from water and from algae results in a maximum concentration factor of 30 and in a mean trophic transfer factor of 4·5 × 10 −3 . The level of contamination of midge larvae from sediment is markedly influenced by the presence of endogenous organic matter. Thus the radionuclide transfer factor is about twice as high for larvae placed in labelled raw sediment than for larvae placed in labelled incinerated sediment, in the presence as in the absence of contaminated planktonic algae. Irrespective of the contamination conditions, 60 Co depuration from midge larvae is a very rapid phenomenon that corresponds, in all cases, to a radionuclide half-life of only a few days

60Co accumulation from sediment and planktonic algae by midge larvae (Chironomus luridus)

International Nuclear Information System (INIS)

Baudin, J.P.; Nucho, R.

1992-01-01

This paper reports the results of several experiments carried out to evaluate uptake and retention by a limicolous midge larva of 60 Co retained in sediment, either adsorbed on mineral particles or bound to planktonic algae. In order to determine their relative contributions in radionuclide accumulation, the different vectors (water, algae and sediment) were first labelled individually and then simultaneously. 60 Co accumulation from water and from algae results in a maximum concentration factor of 30 and in a mean trophic transfer factor of 4.5 x 10 -3 . The level of contamination of midge larvae from sediment is markedly influenced by the presence of endogenous organic matter. Thus the radionuclide transfer factor is about twice as high for larvae placed in labelled raw sediment than for larvae placed in labelled incinerated sediment, in the presence as in the absence of contaminated planktonic algae. Irrespective of the contamination conditions, 60 Co depuration from midge larvae is a very rapid phenomenon that corresponds, in all cases, to a radionuclide half-life of only a few days. (author)

Life cycle responses of the midge Chironomus riparius to polycyclic aromatic compound exposure

NARCIS (Netherlands)

León Paumen, M.; Borgman, E.; Kraak, M.H.S.; van Gestel, C.A.M.; Admiraal, W.

2008-01-01

During acute exposure, polycyclic aromatic compounds (PACs) act mainly by narcosis, but during chronic exposure the same compounds may exert sublethal life cycle effects. The aim of this study was therefore to evaluate the chronic effects of sediment spiked PACs on the emergence of the midge

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

Aquatic invertebrates that ingest large numbers of bacteria produce substantial amounts of the greenhouse gas N2O because of incomplete denitrification in their anoxic gut. We investigated the influence of two key environmental factors, temperature and NO3- availability, on N2O emission from larv...

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.

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

Directory of Open Access Journals (Sweden)

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.

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.

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

Directory of Open Access Journals (Sweden)

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

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.

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

Science.gov (United States)

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

2015-07-01

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

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.

CLUSIACEAE LINDL. E HYPERICACEAE JUSS. NAS RESTINGAS DO ESTADO DO PARÁ, AMAZÔNIA ORIENTAL, BRASIL

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Thiago Teixeira de Oliveira

2015-12-01

Full Text Available O estudo teve como objetivo o tratamento florístico-taxonômico de Clusiaceae e Hypericaceae para as restingas do Estado do Pará. O material foi obtido nos acervos dos Herbários do Museu Paraense Emílio Goeldi (MG, Embrapa Amazônia Oriental (IAN e coletas realizadas na praia do Crispim, Marapanim-PA. As descrições das espécies foram fundamentadas nas características morfológicas e em suas respectivas variações para a flora, foi elaborada uma chave para identificação das mesmas. As famílias encontram-se representadas por quatro táxons, onde Clusiaceae é composta por Clusia fockeana Miq., C. hoffmannseggiana Schltdl., e C. panapanari (Aubl. Choisy., e Hypericaceae apenas por Vismia guianensis (Aubl. Choisy. C. panapanari apresenta-se restrita à formação de mata de restinga. C. hoffmannseggiana e V. guianensis apresentaram distribuição mais ampla nas restingas paraenses. No levantamento feito na coleção nos herbários, constatou-se que coletas, das famílias nas restingas paraenses, ainda são escassas e o esforço de coletas poderá trazer mais informações sobre período de floração e frutificação, além de um provável incremento de novos registros para a área de estudo. Palavras-chave: Cebola brava, Litoral paraense, Taxonomia. DOI: http://dx.doi.org/10.18561/2179-5746/biotaamazonia.v5n4p15-21

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

International Nuclear Information System (INIS)

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

2005-01-01

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

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

Energy Technology Data Exchange (ETDEWEB)

Dubois, Maitee [Institut national de la recherche scientifique - Eau, Terre et Environnement, Universite du Quebec, Quebec City, Quebec, G1K 9A9 (Canada); Hare, Landis [Institut national de la recherche scientifique - Eau, Terre et Environnement, Universite du Quebec, Quebec City, Quebec, G1K 9A9 (Canada)], E-mail: landis@ete.inrs.ca

2009-03-15

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.

Incipient toxicity of lithium to freshwater organisms representing a salmonid habitat

International Nuclear Information System (INIS)

Emery, R.; Klopfer, D.C.; Skalski, J.R.

1981-07-01

Because the eventual development of fusion power reactors could increase the mining, use and disposal of lithium five-fold by the year 2000, potential effects from unusual amounts of lithium in aquatic environments were investigated. Freshwater oganisms representing a Pacific Northwest salmonid habitat were exposed to elevated conentrations of lithium. Nine parameters were used to determine the incipient toxicity of lithium to rainbow trout (Salmo gairdneri), insect larvae (Chironomus sp.), and Columbia River periphyton. All three groups of biota were incipiently sensitive to lithium at concentrations ranging between 0.1 and 1 mg/L. These results correspond with the incipient toxicity of beryllium, a chemically similar component of fusion reactor cores. A maximum lithium concentration of 0.01 mg/L occurs naturally in most freshwater environments (beryllium is rarer). Therefore, a concentration range of 0.01 to 0.1 mg/L may be regarded as approaching toxic concentrations when assessing the hazards of lithium in freshwaters

The effect of 210Pb and stable lead on the induction of mouthpart deformities in chironomid larvae

International Nuclear Information System (INIS)

Bird, G.A.; Schwartz, W.J.; Hoffman, D.

1995-07-01

To determine whether mouthpart deformities in chironomid larvae from Port Hope Harbour, Ontario, are the result of exposure to ionizing radiation or heavy metals in the sediment, Chironomus tentans larvae were exposed in the laboratory to concentrations of 210 Pb and stable lead representative of contaminant levels in the harbour. Exposure to 100, 1000, and 2000 Bq 210 Pb·g -1 dry sediment had no effect on the survival, growth of the larvae or frequency of deformities. Likewise, exposure to 0.5 and 5.0 mg lead·g -1 dry sediment had no effect on the larvae, but exposure to 35.0 mg lead·g -1 dry sediment resulted in 100% mortality of the larvae. These results indicate that the observed mouthpart deformities in chironomid larvae in Port Hope Harbour are not the result of radiation exposure. They also indicate that heavy metals (lead) may be having an impact on the population. (author). 28 refs., 9 tabs., 4 figs

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

International Nuclear Information System (INIS)

Yamada, T.; Janke, H.; Colzato, M.; Beraldo, D.; Mozeto, A.; Botta, C.; Nascimento, M.

2010-01-01

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.

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

International Nuclear Information System (INIS)

Dubois, Maitee; Hare, Landis

2009-01-01

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

Life cycle responses of the midge Chironomus riparius to compounds with different modes of action.

NARCIS (Netherlands)

Marinkovic, M.; Verweij, R.A.; Nummerdor, G.A.; Jonker, M.J.; Kraak, M.H.S.; Admiraal, W.

2011-01-01

Compounds with different modes of action may affect life cycles of biota differently. The aim of the present study was therefore to investigate the impact of four chemicals with different modes of action, including the essential metal copper, the nonessential metal cadmium, the organometal

Life cycle responses of the midge Chironomus riparius to compounds with different modes of action

NARCIS (Netherlands)

Marinkovic, M.; Verweij, R.A.; Nummerdor, G.A.; Jonker, M.J.; Kraak, M.H.S.; Admiraal, W.

2011-01-01

Compounds with different modes of action may affect life cycles of biota differently. The aim of the present study was therefore to investigate the impact of four chemicals with different modes of action, including the essential metal copper, the nonessential metal cadmium, the organometal

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

Science.gov (United States)

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

2014-01-01

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

Substitution time of natural food by artificial diet on survival rate and growth of pacific white shrimp (Litopenaeus vannamei postlarvae during rearing in low salinity media

Directory of Open Access Journals (Sweden)

Ferdinand Hukama Taqwa

2011-01-01

Full Text Available This research was conducted to determine natural food substitution time by artificial diet   after salinity acclimatization from 20 ppt until 2 ppt, which can increase survival and growth of (Litopenaeus vannamei postlarvae during rearing period. Design experiment was completely randomized design with five treatments and three replications of natural food Chironomus sp.  (60% of crude protein substitution time by artificial diet (40% of crude protein at day: 1 (A, 7 (B, 14 (C, 21 (D and full natural food without artificial diet (E during 28 days rearing period. White shrimp postlarvae and rearing media in this experiment based from best result of earlier research that is PL25 from acclimatization in media 2 ppt with addition of potassium 25 ppm to freshwater media.  The densities of PL25 white shrimp were 20 PLs/50 liters of 2 ppt media. The result of this experiment showed that the use of artificial diet as soon as after salinity acclimatization (PL25 gave best performance production compared to which only that was given natural food Chironomus sp. during experiment or with treatment by artificial diet substitution at day-7, day-14 or day-21, shown with the highest value of food consumption level, protein retention, energy retention, daily growth rate and food efficiency. Survival rate of PL54 was above 80% and not significant different between treatment. That is supported by chemical-physical value of water quality still in range appropriate to survival rate of white shrimp post larvae during a rearing period. The result of this experiment indicated that requirement nutrient of PL25 in low salinity did not fulfilled if only rely on natural food, so that require artificial diet with nutrition content to support growth and survival rate of white shrimp post larvae more maximal. Key words: salinity, natural food, artificial diet, Pacific white shrimp   ABSTRAK Tujuan penelitian ini adalah untuk menentukan waktu penggantian pakan alami oleh

Origens pluriétnicas no cotidiano da pesca na Amazônia: contribuições para projeto de estudo pluridisciplinar

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Lourdes Gonçalves Furtado

Full Text Available O presente texto é versão de uma conferência proferida no Departamento de Genética da Universidade Federal do Pará (UFPA, no marco do tema Populações amazônicas ontem, hoje e perspectivas para o futuro. Essa conferência enfatizava a relevância das contribuições dos primeiros formadores da sociedade amazônica para a sociedade de hoje e vem agora compor o cenário deste volume temático do Boletim do Museu Goeldi. Os dados apresentados são frutos de trabalhos de campo anteriores da autora em diferentes momentos e lugares da região e associados à pesquisa bibliográfica e à experiência pessoal da autora em diversos 'lugares de pescadores' do litoral, médio Amazonas, estuário amazônico e ilha do Marajó. Este conjunto serviu de base e instrumento para estas reflexões propositivas para novas pesquisas mutidisciplinares, tendo em vista preencher lacunas sobre a história da pesca na Amazônia. Assim, propõese a evocar as origens pluriétnicas da sociedade e cultura que se formaram na Amazônia visando à maior clareza sobre as relações entre os primeiros contingentes formadores da sociedade amazônica e os segmentos sociais contemporâneos. Com isso imagina-se trazer à reflexão o valor das contribuições socioculturais e ambientais daqueles diferentes contigentes sociais e chamar atenção para o legado sociocultural deixado pela ancestralidade indígena que permeia a ocupação humana na região.

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

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Paula Daniela Raiol Bitar de Araujo

2013-10-01

Full Text Available 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 (Sus scrofa L. inteiro (com vísceras, de 14,5 Kg, recém abatido. Este foi exposto sob uma armadilha do tipo suspensa modificada, adequada à coletas de insetos adultos, sendo que também foram coletadas larvas e pupas, diretamente na carcaça. A ocorrência dos insetos adultos e de seus estágios larvais foi correlacionada com o tempo de morte do animal, a fim de possibilitar futuras inferências de tempo de morte com base na presença e dispersão destes insetos. O tempo de decomposição e a duração de cada estágio de decomposição foram registrados, tendo sido afetados provavelmente pelo tamanho da carcaça e pela estação do ano. Diferenças quanto ao padrão de sucessão não foram observadas

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.

Algal food selection and digestion by larvae of the pestiferous chironomid Chironomus crassicaudatus under laboratory conditions

Czech Academy of Sciences Publication Activity Database

Frouz, Jan; Ali, A.; Lobinske, R. J.

2004-01-01

Roč. 20, č. 4 (2004), s. 458-461 ISSN 8756-971X Institutional research plan: CEZ:AV0Z6066911 Keywords : Chironomidae * nuisance midge * cyanobacteria Subject RIV: EH - Ecology, Behaviour Impact factor: 0.691, year: 2004

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

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

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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

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

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

Directory of Open Access Journals (Sweden)

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

Exclusion of mRNPs and ribosomal particles from a thin zone beneath the nuclear envelope revealed upon inhibition of transport

International Nuclear Information System (INIS)

Kylberg, Karin; Bjoerk, Petra; Fomproix, Nathalie; Ivarsson, Birgitta; Wieslander, Lars; Daneholt, Bertil

2010-01-01

We have studied the nucleocytoplasmic transport of a specific messenger RNP (mRNP) particle, named Balbiani ring (BR) granule, and ribosomal RNP (rRNP) particles in the salivary glands of the dipteran Chironomus tentans. The passage of the RNPs through the nuclear pore complex (NPC) was inhibited with the nucleoporin-binding wheat germ agglutinin, and the effects were examined by electron microscopy. BR mRNPs bound to the nuclear basket increased in number, while BR mRNPs translocating through the central channel decreased, suggesting that the initiation of translocation proper had been inhibited. The rRNPs accumulated heavily in nucleoplasm, while no or very few rRNPs were recorded within nuclear baskets. Thus, the transport of rRNPs had been blocked prior to the entry into the baskets. Remarkably, the rRNPs had been excluded both from baskets and the space in between the baskets. We propose that normally basket fibrils move freely and repel RNPs from the exclusion zone unless the particles have affinity for and bind to nucleoporins within the baskets.

Isonychia spp. and macroinvertebrate community responses to stressors in streams utilizing the benthic in situ toxicity identification evaluation (BiTIE) method

International Nuclear Information System (INIS)

Custer, Kevin W.; Burton, G. Allen

2008-01-01

Exposures of caged organisms in situ have proven to be a useful way to improve exposure realism and link to stressor effects in aquatic assessments of hazard or risk. A novel cage system, the benthic in situ toxicity identification evaluation (BiTIE), was developed for benthic macroinvertebrates (surrogate species, resident populations and communities) to separate low and high flow effects, and major chemical classes of stressors in streams. Three resin types were used to separate the chemical stressors in the streams Honey Creek and Little Beavercreek, Ohio, USA: Dowex TM Optipore TM (non-polar organics), zeolite (ammonia), and polywool (control). Isonychia spp. sensitivity was compared to Chironomus tentans, and no significant differences were found (p > 0.05). Isonychia spp. growth (length) showed a stressor response in the zeolite treatments, and community testing revealed improved metric responses in the Dowex TM treatments. The BiTIE chamber system demonstrated stressor-response relationships using sublethal and multimetric endpoints. - Use of an indigenous aquatic insect and benthic macroinvertebrate communities allows for discerning the stressors in low and high flows with an in situ TIE approach

ELISA detection of multixenobiotic resistance transporter induction in indigenous freshwater Chironomidae larvae (Diptera): A biomarker calibration step for in situ monitoring of xenobiotic exposure

Energy Technology Data Exchange (ETDEWEB)

Moreau, X.; Saez, G.; Thiery, A. [Equipe ' Biomarqueurs and Bioindicateurs Environnementaux' , UMR-CNRS 6116 IMEP, Universite de Provence, 3 Place Victor Hugo, 13331 Marseille cedex 3 (France); Clot-Faybesse, O.; Guiraudie-Capraz, G. [' Neurobiologie Integrative et Adaptative' -UMR 6149, Universite de Provence, 3 Place Victor Hugo, 13331 Marseille cedex 3 (France); Bienboire-Frosini, C. [' Neurobiologie Integrative et Adaptative' -UMR 6149, Universite de Provence, 3 Place Victor Hugo, 13331 Marseille cedex 3 (France); Pherosynthese, Le Rieu Neuf, 84490 St Saturnin d' Apt (France); Martin, C. [Equipe ' Biomarqueurs and Bioindicateurs Environnementaux' , UMR-CNRS 6116 IMEP, UAPV, 33 rue Louis Pasteur, 84000 Avignon (France); De Jong, L. [Equipe ' Biomarqueurs and Bioindicateurs Environnementaux' , UMR-CNRS 6116 IMEP, Universite de Provence, 3 Place Victor Hugo, 13331 Marseille cedex 3 (France)], E-mail: laetitia.moreau@univ-provence.fr

2008-06-15

A new simple and sensitive method to distinguish chemically polluted from unpolluted situations in freshwater ecosystems is reported. For this purpose, Chironomus gr thumni larvae were collected from a polluted urban river downstream a sewage treatment plant. For the first time, ELISA assay was used to semi-quantify the multixenobiotic resistance transporters (MXR) in these small pertinent bioindicators. The use of samples immediately fixed in the field gives a delay to isolate larvae and allows multi-sampling along a longitudinal transect in a river at a given time. Results exhibit an induction of MXR proteins in larvae from the polluted river and a deinduction in larvae maintained 11 days in unpolluted water. They show new evidences to use midge larvae in biomonitoring environmental programs. They answer to first biomarker calibration steps for the ongoing development of MXR transporters as a detection tool of xenobiotic impacts on bioindicator invertebrates in their freshwater habitats. - Semi-quantification of midge larval MXR transporters by ELISA is a simple and sensitive method to detect chemically polluted situations in running freshwaters.

ELISA detection of multixenobiotic resistance transporter induction in indigenous freshwater Chironomidae larvae (Diptera): A biomarker calibration step for in situ monitoring of xenobiotic exposure

International Nuclear Information System (INIS)

Moreau, X.; Saez, G.; Thiery, A.; Clot-Faybesse, O.; Guiraudie-Capraz, G.; Bienboire-Frosini, C.; Martin, C.; De Jong, L.

2008-01-01

A new simple and sensitive method to distinguish chemically polluted from unpolluted situations in freshwater ecosystems is reported. For this purpose, Chironomus gr thumni larvae were collected from a polluted urban river downstream a sewage treatment plant. For the first time, ELISA assay was used to semi-quantify the multixenobiotic resistance transporters (MXR) in these small pertinent bioindicators. The use of samples immediately fixed in the field gives a delay to isolate larvae and allows multi-sampling along a longitudinal transect in a river at a given time. Results exhibit an induction of MXR proteins in larvae from the polluted river and a deinduction in larvae maintained 11 days in unpolluted water. They show new evidences to use midge larvae in biomonitoring environmental programs. They answer to first biomarker calibration steps for the ongoing development of MXR transporters as a detection tool of xenobiotic impacts on bioindicator invertebrates in their freshwater habitats. - Semi-quantification of midge larval MXR transporters by ELISA is a simple and sensitive method to detect chemically polluted situations in running freshwaters

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.

Ecotoxicological effect characterisation of widely used organic UV filters.

Science.gov (United States)

Kaiser, D; Sieratowicz, A; Zielke, H; Oetken, M; Hollert, H; Oehlmann, J

2012-04-01

Chemical UV filters are used in sun protection and personal care products in order to protect consumers from skin cancer induced by ultraviolet (UV) radiation. The present study aims to evaluate the effects of three common UV filters butyl-methoxydibenzoylmethane (B-MDM) ethylhexyl-methoxycinnamate (EHMC) and octocrylene (OCR) on aquatic organism, focussing particularly on infaunal and epibentic invertebrates (Chironomus riparius, Lumbriculus variegatus, Melanoides tuberculata and Potamopyrgus antipodarum). Due to their life habits, these organism are especially affected by lipophilic substances. Additionally, two direct sediment contact assays utilising zebra fish (Danio rerio) embryos and bacteria (Arthrobacter globiformis) were conducted. EHMC caused a toxic effect on reproduction in both snails with lowest observed effect concentrations (LOEC) of 0.4 mg/kg (Potamopyrgus antipodarum) and 10 mg/kg (Melanoides tuberculata). At high concentrations sublethal effects could be observed for D. rerio after exposure to EHMC (NOEC 100 mg/kg). B-MDM and OCR showed no effects on any of the tested organism. Copyright © 2011 Elsevier Ltd. All rights reserved.

The effect of {sup 210}Pb and stable lead on the induction of mouthpart deformities in chironomid larvae

Energy Technology Data Exchange (ETDEWEB)

Bird, G A; Schwartz, W J; Hoffman, D [Atomic Energy of Canada Ltd., Pinawa, MB (Canada). Whiteshell Labs.

1995-07-01

To determine whether mouthpart deformities in chironomid larvae from Port Hope Harbour, Ontario, are the result of exposure to ionizing radiation or heavy metals in the sediment, Chironomus tentans larvae were exposed in the laboratory to concentrations of {sup 210}Pb and stable lead representative of contaminant levels in the harbour. Exposure to 100, 1000, and 2000 Bq {sup 210}Pb{center_dot}g{sup -1} dry sediment had no effect on the survival, growth of the larvae or frequency of deformities. Likewise, exposure to 0.5 and 5.0 mg lead{center_dot}g{sup -1} dry sediment had no effect on the larvae, but exposure to 35.0 mg lead{center_dot}g{sup -1} dry sediment resulted in 100% mortality of the larvae. These results indicate that the observed mouthpart deformities in chironomid larvae in Port Hope Harbour are not the result of radiation exposure. They also indicate that heavy metals (lead) may be having an impact on the population. (author). 28 refs., 9 tabs., 4 figs.

Çapalı Gölü (Afyon Makrobentik Omurgasızlarının Taban Yapısı ve Su Kalitesine Bağlı Olarak Dağılımı.

Directory of Open Access Journals (Sweden)

Ö. Osman Ertan

2015-12-01

Full Text Available Temmuz 2000 ve Haziran 2001 tarihleri arasında yapılan bu çalışmada, Çapalı Gölü’nün bazı su kalitesi parametreleri ile makrobentik omurgasızlarının dağılım ve yoğunluğu ikişer ay arayla, bir yıl boyunca izlenmiştir. Kaynak suyu özelliği gösteren I. istasyonda Theodoxus anatolicus (Recluz, 1841, Graecoanatolica tenuis (Radoman, 1943 (Gastropoda ve Trichoptera larvaları yoğun olarak bulunurken; mezotrofik ve ötrofik özellik gösteren II. ve III. istasyonlarda makrobentik organizma çeşitliliği ve yoğunluğunun çok düşük düzeyde olduğu tespit edilmiştir. Ötrofik-hiperötrofik özellikte olan IV. istasyonda ise Chironomus larvaları (Diptera, Tubifex sp. (Oligochaeta ve Asellus aquaticus (Linnaeus, 1758 (Isopoda yoğun olarak belirlenmiştir

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

International Nuclear Information System (INIS)

Bruno, V.

1990-11-01

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 [fr

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

Science.gov (United States)

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

2013-01-01

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

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

Energy Technology Data Exchange (ETDEWEB)

Campenhout, K. van [Ecophysiology, Biochemistry and Toxicology Group, Department of Biology, University of Antwerp, Groenenborgerlaan 171, B-2020 Antwerp (Belgium); Bervoets, L. [Ecophysiology, Biochemistry and Toxicology Group, Department of Biology, University of Antwerp, Groenenborgerlaan 171, B-2020 Antwerp (Belgium)]. E-mail: lieven.bervoets@ua.ac.be; Blust, R. [Ecophysiology, Biochemistry and Toxicology Group, Department of Biology, University of Antwerp, Groenenborgerlaan 171, B-2020 Antwerp (Belgium)

2007-02-15

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 {sup o}C to 15 {sup o}C 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.

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)

Campenhout, K. van; Bervoets, L.; Blust, R.

2007-01-01

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 o C to 15 o C 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

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)

Oetken, Matthias; Stachel, Burkhard; Pfenninger, Markus; Oehlmann, Joerg

2005-01-01

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

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

Energy Technology Data Exchange (ETDEWEB)

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

2016-08-15

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

Determinação de hemogregarina em Boa constrictor constrictor mantidos em cativeiro

Directory of Open Access Journals (Sweden)

Monique A. Luz

2012-08-01

Full Text Available O presente estudo teve como objetivo determinar a presença de hemogregarina em boídeos mantidos em cativeiro no Estado do Pará, bem como, relacionar a hemoparasitose com pre-disposição sexual, alterações clínicas e hematológicas e a presença de ectoparasitos. Esta pesquisa teve autorização do Sistema de Autorização e Informação em Biodiversidade do Instituto Brasileiro do Meio Ambiente e dos Recursos Naturais Renováveis para ser realizado. Utilizaram-se 19 serpentes da família Boidae mantidas em cativeiro, pertencentes ao "Museu Paraense Emilio Goeldi" (Belém/PA e "Sítio Xerimbabo" (Santo Antônio do Tauá/PA. A pesquisa de hemogregarina foi realizada em esfregaços sanguíneos examinados no aumento de 400x, enquanto que a parasitemia foi determinada contando- se 550 hemácias em aumento de 1000x. Do total de animais estudados (n=19, nove encontraram-se parasitados (47,36%, não havendo correlação entre presença de hemogregarina, pré-disposição sexual, alterações clínicas e hematológicas nas serpentes hospedeiras. A correlação da hemoparasitose foi detectada apenas quanto à presença de ectoparasitas nas serpentes, no entanto, estudos adicionais são necessários para verificar a prevalência de hemogregarinas em animais mantidos em cativeiro no Estado do Pará, visto que, existe grande lacuna de dados na literatura veterinária especializada no que diz respeito à fauna da região amazônica.

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

Directory of Open Access Journals (Sweden)

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.

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

, respectively, which was mostly due to stimulation of sedimentary denitrification; incomplete denitrification in the guts accounted for up to 20% of the N2O efflux. Phylotype richness of the nitrate reductase gene narG was significantly higher in sediment with than without larvae. In the gut, 47 narG phylotypes...... 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...... nosZ wasdifferent in sediments with and without larvae. Hence, C. plumosus increases activity and diversity, but not overall abundance of nitrate-reducing bacteria, probably by providing additional ecological niches in its burrow and gut....

Reducing the toxicity of refinery effluent using seed extract and micro porous carbon from seed husks of moringa oleifera

International Nuclear Information System (INIS)

Gbem, T. T.; Balogun, J. K.; Lawal, F. A.

1998-01-01

Contamination of the environment with industrial chemicals and/or effluent has become a major problem. In this study, the toxicity of an NNPC refinery effluent was tested by exposing a commonly occurring invertebrate, Chironomus sp. (early larva stage) using the 96-h static bioassay to establish the LC 5 0 value. Seed extract from a widely distributed tropical plant, moringa oleifera was used to treat the effluent employing a modified laboratory jar test procedure. Hardness and alkalinity were reduced to between 19 and 30% with reduction found to be dose-dependent. Adsorption isotherms were established and were found to approximate the Langmuir type. Char from M. oleifera seed husks was also used to test the sorption of toxicants. A single toxicant from the effluent phenol, was used for sorption studies using pseudo-equilibrium batch contact experiments. Sorption was found to obey a Freundlich type adsorption isotherm (of the form q = KC), Retesting the toxicity of the effluent by re-introducing a different set of the test organism after treatment yielded no significant mortality. Moringa oleifera seed extract, char and possibly activated carbon from seed husks hold a promise to further reduction of the toxicity of refinery effluent

Isonychia spp. and macroinvertebrate community responses to stressors in streams utilizing the benthic in situ toxicity identification evaluation (BiTIE) method

Energy Technology Data Exchange (ETDEWEB)

Custer, Kevin W. [Department of Earth and Environmental Sciences, Wright State University, 127 Allyn Hall, 3640 Colonel Glenn Highway, Dayton, OH 45435 (United States)], E-mail: custer.4@wright.edu; Burton, G. Allen [Department of Earth and Environmental Sciences, Wright State University, 127 Allyn Hall, 3640 Colonel Glenn Highway, Dayton, OH 45435 (United States)

2008-01-15

Exposures of caged organisms in situ have proven to be a useful way to improve exposure realism and link to stressor effects in aquatic assessments of hazard or risk. A novel cage system, the benthic in situ toxicity identification evaluation (BiTIE), was developed for benthic macroinvertebrates (surrogate species, resident populations and communities) to separate low and high flow effects, and major chemical classes of stressors in streams. Three resin types were used to separate the chemical stressors in the streams Honey Creek and Little Beavercreek, Ohio, USA: Dowex{sup TM} Optipore{sup TM} (non-polar organics), zeolite (ammonia), and polywool (control). Isonychia spp. sensitivity was compared to Chironomus tentans, and no significant differences were found (p > 0.05). Isonychia spp. growth (length) showed a stressor response in the zeolite treatments, and community testing revealed improved metric responses in the Dowex{sup TM} treatments. The BiTIE chamber system demonstrated stressor-response relationships using sublethal and multimetric endpoints. - Use of an indigenous aquatic insect and benthic macroinvertebrate communities allows for discerning the stressors in low and high flows with an in situ TIE approach.

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

Science.gov (United States)

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

1995-01-01

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

Structure of the macrozoobenthos as an indicator of different types of pollution in running waters

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Simić Vladica M.

2002-01-01

Full Text Available Hydrobiological research on streams with different dominant forms of pollution (anthropogenic eutrophication, organic pollution, toxic pollution, trans-saprobic pollution in the central part of the Balkan Peninsula (territory of Serbia and Montenegro indicates that these different forms of pollution can be detected on the basis of structure of the macrozoobenthos community and individual indicator taxa. It is established from the obtained results that the greatest community diversity occurs in the case of anthropogenic eutrophication or weak organic pollution as a dominant process, where phytophilous and/or detritophagic forms (Cloeon, Polypedilum, Asellus, Stylaria, Erpobdella, Gammarus are dominant in the community. In the cases of very strong organic pollution, the macrozoobenthos community is characterized by mass development of certain taxa of the group Oligochaeta (Tubificidae and Chironomidae larvae {Chironomus gr. thummi. Depending on the strength and contribution of organic, toxic, and/or transsaprobic components, toxic pollution and mixed pollution arc characterized by a more or less heterogeneous and nonspecific population. However, a common feature is the presence of a small number of taxa with populations of a relatively low density, or the occurrence of individual specimens belonging to different groups of animals.

A persistent homology approach to collective behavior in insect swarms

Science.gov (United States)

Sinhuber, Michael; Ouellette, Nicholas T.

Various animals from birds and fish to insects tend to form aggregates, displaying self-organized collective swarming behavior. Due to their frequent occurrence in nature and their implications for engineered, collective systems, these systems have been investigated and modeled thoroughly for decades. Common approaches range from modeling them with coupled differential equations on the individual level up to continuum approaches. We present an alternative, topology-based approach for describing swarming behavior at the macroscale rather than the microscale. We study laboratory swarms of Chironomus riparius, a flying, non-biting midge. To obtain the time-resolved three-dimensional trajectories of individual insects, we use a multi-camera stereoimaging and particle-tracking setup. To investigate the swarming behavior in a topological sense, we employ a persistent homology approach to identify persisting structures and features in the insect swarm that elude a direct, ensemble-averaging approach. We are able to identify features of sub-clusters in the swarm that show behavior distinct from that of the remaining swarm members. The coexistence of sub-swarms with different features resembles some non-biological systems such as active colloids or even thermodynamic systems.

Evaluated fate and effects of atrazine and lambda-cyhalothrin in vegetated and unvegetated microcosms.

Science.gov (United States)

Bouldin, J L; Farris, J L; Moore, M T; Smith, S; Stephens, W W; Cooper, C M

2005-10-01

Contaminants such as nutrients, metals, and pesticides can interact with constructed wetlands and existing drainage ditches used as agricultural best-management practices. Our research has shown that the presence of macrophytes and a hydrologic regime aid in the transfer and transformation of pesticides associated with agricultural runoff. This study consisted of application of both atrazine (triazine herbicide) and lambda-cyhalothrin (pyrethroid insecticide) to vegetated and unvegetated microcosms in order to measure the fate and effects of pesticides applied at suggested field application rates. Exposures focused on monocultures of Ludwigia peploides (water primrose) and Juncus effusus (soft rush). Pesticide sorption was evident through concentrations of atrazine and lambda-cyhalothrin in plant tissue as high as 2461.4 and 86.50 microg/kg, respectively. Toxicity was measured in water from unvegetated microcosms for 28 days and in Chironomus tentans (midge larvae) exposed to sediment collected from 3 h to 56 days in microcosms receiving the pesticide combination. The comparative survival of test organisms in this study suggests that effective mitigation of pesticides from runoff can depend on the macrophyte contact and vegetative attributes associated with ditches. (c) 2005 Wiley Periodicals, Inc.

Survival of Salmonella enterica in Freshwater and Sediments and Transmission by the Aquatic Midge Chironomus tentans (Chironomidae: Diptera)

Science.gov (United States)

Moore, Barry C.; Martinez, Edward; Gay, John M.; Rice, Daniel H.

2003-01-01

Survival of a nalidixic acid-resistant strain of Salmonella enterica serovar Typhimurium mr-DT-104 in water and sediments was tested using artificially contaminated aquaria. Water samples remained culture positive for salmonella for up to 54 days. Sediment samples were culture positive up to 119 days. In addition, potential mechanisms for spreading salmonella in the environments by chironomid larvae and adults were tested. We evaluated the acquisition of mr-DT-104 by chironomids from contaminated aquatic sediments and subsequent spread to uncontaminated sediments. Larval chironomids raised in contaminated sediments became culture positive, and the bacteria were carried over to adults after emergence. Contamination of clean sediments by chironomid larvae was not demonstrated. These findings clearly suggest that mr-DT-104 serovar organisms can survive in aquatic sediments for at least several months. Uptake of salmonellae by chironomid larvae and adults suggests that they are possible vectors of mr-DT-104 in both aquatic and terrestrial environments, although the role of larval defecation in movement of bacteria to new sediments was not demonstrated. PMID:12902242

Redescripción y algunos aspectos ecológicos de Girardia tigrina, G. cameliae y G. paramensis (Dugesiidae, Tricladida en Antioquia, Colombia Redescription and some ecological aspects of Girardia tigrina, G. cameliae y G. paramensis (Dugesiidae, Tricladida in Antioquia, Colombia

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Mauricio A Muñoz

2007-12-01

Full Text Available Turbellaria está integrada por 2 órdenes: Catenulida y Rhabditophora. Dentro del último, el suborden Paludicola comprende las familias Dendrocoelidae, Dugesiidae y Planariidae. En este estudio fueron encontradas: Girardia cameliae, G. paramensis y G. tigrina (Dugesiidae. Fueron analizados 22 sistemas acuáticos (captura manual en zonas de remanso del centro y sur oriente de Antioquia. En 3 individuos por especie, se hizo descripción de: ancho, longitud y color corporal; forma y tamaño de cabeza; posición auricular; distancia entre manchas oculares; longitud y posición de faringe. Se efectuó análisis histológico de: gonoporo; bulbo, papila, glándulas y lúmen peneal; vesículas seminales y vasos deferentes; atrio masculino; testículos; canal bursal y bolsa copuladora; ovario y oviductos; glándulas de la cáscara. Se midieron: oxigeno disuelto, pH, conductividad y dureza en el agua. Se realizó reconstrucción gráfica de órganos reproductivos (caracteres taxonómicos en cortes histológicos seriados. G. tigrina y G. paramensis, presentaron amplia distribución geográfica. Estas especies consumieron ex situ: Daphnia pulex, Chironomus sp., Culex sp. y Drosophila sp. (estados larvales. Tales planarias prefirieron aguas clase II y III (según BMWP/Col. Los aspectos físicos y químicos no exhibieron diferencias entre las preferencias de las especies. G. cameliae se encontró en una sola localidad en condiciones particulares.The Turbellaria comprises 2 orders: Catenulida and Rhabditophora. In the latter, the suborder Paludicola contains the families Dendrocoelidae, Dugesiidae and Planariidae. In this study, we found Girardia cameliae, Girardia paramensis and Giardia tigrina (Dugesiidae in 22 aquatic systems using manual capture in river ponds zones of central and southeastern Antioquia. In 3 individuals per species, a description of: corporal color, length, and wide; head form and size; auricles position; intraocular distance; pharynx

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

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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

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

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.

Environmental effect of resort centres on the distribution of aquatic insect fauna in Ethiope River, Delta State, Nigeria

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Edore Edwin Ito

2017-11-01

Full Text Available Objective: To assess water quality and diversity of aquatic insects relative to effluents discharge from resort centres in Ethiope River. Methods: Water samples collected from three study stations were analyzed using APHA methods while the kick sampling techniques were used for collection of aquatic insects. The obtained data were subjected to statistical analysis at significance level of 0.05. Results: Among the study stations, water temperature varied from 20 °C to 34 °C with a mean temperature of (26.17 ± 2.37 °C, while pH was recorded from 5.57 ± 0.18 to 5.94 ± 0.21. Statistically, water temperature, pH, dissolved oxygen and conductivity were significantly different (P 0.05 in the stations. Conclusions: Significant relationships were recorded between water quality parameters and occurrence of Neoperla spio, Caenis horaria, Baetis and Chironomus species. The observed changes in aquatic insect composition were principally due to alteration in water quality. The weak correlation between aquatic insects and water quality can be attributed to functional adaptations to environmental changes. Aquatic insects have been proved to be good bioindicator of pollution and long-term monitoring of the aquatic insects is necessary for water quality evaluation in Ethiope River.

Feeding type and development drive the ingestion of microplastics by freshwater invertebrates.

Science.gov (United States)

Scherer, Christian; Brennholt, Nicole; Reifferscheid, Georg; Wagner, Martin

2017-12-05

Microscopic plastic items (microplastics) are ubiquitously present in aquatic ecosystems. With decreasing size their availability and potential to accumulate throughout food webs increase. However, little is known on the uptake of microplastics by freshwater invertebrates. To address this, we exposed species with different feeding strategies to 1, 10 and 90 µm fluorescent polystyrene spheres (3-3 000 particles mL -1 ). Additionally, we investigated how developmental stages and a co-exposure to natural particles (e.g., food) modulate microplastic ingestion. All species ingested microplastics in a concentration-dependent manner with Daphnia magna consuming up to 6 180 particles h -1 , followed by Chironomus riparius (226 particles h -1 ), Physella acuta (118 particles h -1 ), Gammarus pulex (10 particles h -1 ) and Lumbriculus variegatus (8 particles h -1 ). D. magna did not ingest 90 µm microplastics whereas the other species preferred larger microplastics over 1 µm in size. In C. riparius and D. magna, size preference depended on the life stage with larger specimens ingesting more and larger microplastics. The presence of natural particles generally reduced the microplastics uptake. Our results demonstrate that freshwater invertebrates have the capacity to ingest microplastics. However, the quantity of uptake depends on their feeding type and morphology as well as on the availability of microplastics.

Cryptic species in the nuisance midge Polypedilum nubifer (Skuse (Diptera: Chironomidae) and the status of Tripedilum Kieffer.

Science.gov (United States)

Cranston, Peter S; Martin, Jon; Spies, Martin

2016-02-15

Polypedilum nubifer (Skuse, 1889), originally described from Australia, is an apparently widespread species of Chironomidae (Diptera) that can attain nuisance densities in some eutrophic water bodies. Appropriate management depends upon the identity and ability to distinguish from potential cryptic taxa. A morphological study of larvae, pupae and adults of both sexes confirmed P. nubifer as widely distributed and frequently abundant, but also revealed two previously cryptic species of limited distribution in northern Australia. These species are described as new and illustrated in all stages here. Polypedilum quasinubifer Cranston sp. n. is described from north-west Queensland, Australia and also from Thailand and Singapore. Polypedilum paranubifer Cranston sp. n. is known only from retention ponds of a uranium mine in Northern Territory, Australia. Unusual morphological features of P. nubifer including alternate Lauterborn organs on the larval antenna, cephalic tubules on the pupa and frontal tubercles on the adult head are present in both new species as well. Newly slide-mounted types of Polypedilum pelostolum Kieffer, 1912 (lectotype designated here) confirm synonymy to Chironomus nubifer Skuse, 1889, examined also as newly-slide mounted types. Reviewed plus new evidence does not support recognition of Tripedilum Kieffer, 1921 as a separate taxon; therefore, Tripedilum is returned to junior synonymy with Polypedilum s. str.

Discontinuous movement of mRNP particles in nucleoplasmic regions devoid of chromatin

Science.gov (United States)

Siebrasse, Jan Peter; Veith, Roman; Dobay, Akos; Leonhardt, Heinrich; Daneholt, Bertil; Kubitscheck, Ulrich

2008-01-01

Messenger ribonucleoprotein particles (mRNPs) move randomly within nucleoplasm before they exit from the nucleus. To further understand mRNP trafficking, we have studied the intranuclear movement of a specific mRNP, the BR2 mRNP, in salivary gland cells in Chironomus tentans. Their polytene nuclei harbor giant chromosomes separated by vast regions of nucleoplasm, which allows us to study mRNP mobility without interference of chromatin. The particles were fluorescently labeled with microinjected oligonucleotides (DNA or RNA) complementary to BR2 mRNA or with the RNA-binding protein hrp36, the C. tentans homologue of hnRNP A1. Using high-speed laser microscopy, we followed the intranuclear trajectories of single mRNPs and characterized their motion within the nucleoplasm. The Balbiani ring (BR) mRNPs moved randomly, but unexpectedly, in a discontinuous manner. When mobile, they diffused with a diffusion coefficient corresponding to their size. Between mobile phases, the mRNPs were slowed down 10-to 250-fold but were never completely immobile. Earlier electron microscopy work has indicated that BR particles can attach to thin nonchromatin fibers, which are sometimes connected to discrete fibrogranular clusters. We propose that the observed discontinuous movement reflects transient interactions between freely diffusing BR particles and these submicroscopic structures. PMID:19074261

Disturbance caused by freshwater releases of different magnitude on the aquatic macroinvertebrate communities of two coastal lagoons

Science.gov (United States)

Cañedo-Argüelles, Miguel; Rieradevall, Maria

2010-06-01

The response of the aquatic macroinvertebrate communities to freshwater releases of different magnitude and persistence was investigated in two Mediterranean coastal lagoons (Ca l'Arana and Ricarda). The study was carried out during 14 months (June 2004-July 2005) in which different environmental variables and the macroinvertebrate communities associated with two different habitats, the Phragmites australis belt and the deep area of the lagoons, were sampled monthly. Additionally, potential colonizing sources were identified through the analysis of Chironomidae pupal exuviae. The initial response of the communities to the freshwater releases was similar, being characterized by a peak of opportunistic taxa (mainly Naididae), but the late response was different for each lagoon. In the Ca l'Arana, the magnitude of the freshwater release was higher (salinity dropped below five, which is the limit commonly established for most freshwater species) and its persistence was also higher, allowing the colonization of the lagoon by new insect taxa, which replaced the brackish water species. In the Ricarda, the salinity never dropped beyond five and pre-disturbance conditions were rapidly re-established. This, together with the acclimatizing mechanisms showed by the species Chironomus riparius and Hediste diversicolor, permitted the recovery of the pre-disturbance macroinvertebrate community.

Aquatic macroinvertebrates associated with roots of Eichhornia azuera (Swarts Kunth (Pontederiaceae in an oxbow lake in Pantanal, MS

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Hugo Henrique L. Saulino

2014-09-01

Full Text Available Macrophytes play an important role in the community structure of aquatic systems. In this study, we examined the macroinvertebrate communities within 20 Eichhornia azurea roots in an oxbow lake in Pantanal (MS during dry season. Species abundance and richness were compared via linear regression, and the mean relative proportion of macroinvertebrates among root samples was determined. Macroinvertebrates were identified to the lowest practical taxonomic level, and root volume was measured using the volume displacement method. We identified 371 specimens, belonging to 31 families and 21 taxonomic groups. Chironomus sp. (Chironomidae, Slavinia sp. and Dero sp. (Naididae, all detritivores, were most the represented taxon. Regression analysis indicated a positive correlation between root volume and the abundance and richness of the macroinvertebrate community. Analysis of variance showed no statistically significant differences between species abundance and richness among different E. azuera root volumes, however we did observe a trend toward a positive correlation of both variables with increasing root volume. We suspect that greater root volumes should increase microhabitat availability, which could explain this observed trend. Our results indicate that E. azurea roots may play an important ecologic role (e.g., by providing shelter, food stock in lake macroinvertebrate communities.

Diversity and spatial and temporal variation of benthic macroinvertebrates with respect to the trophic state of Lake Figueira in the South of Brazil

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Fernanda Blauth de Lima

2013-12-01

Full Text Available Benthic macroinvertebrates are widely used in evaluations of environmental impact and recommended in biomonitoring, but little used in Brazilian lentic environments. One of the main objectives has been to explain and predict the distribution of those species according to environmental characteristics. Thus, the study aims to characterize the predominant fauna of the Lake Figueira sediment and its relationship with organic matter and depth, analyzing seasonal variation in communities and aiming to select bioindicators of the trophic state. Sampling was carried out from January 2008 to January 2009, along the lagoon fetch, with an Ekmann-Birge dredge (area 225 cm². Taxon richness was not significantly related with depth and organic matter content, but those variables were highly correlated (r = 0.962; r² = 0.926 and p < 0.001. The constant oxygenation of the whole water column allows the occurrence of organisms, independent of depth and organic matter content. Chironomidae was the most abundant taxon and from the frequency of occurrence, abundance and clustering analysis it was possible to select Larsia sp. , Goeldichironomus maculatus, Xenochironomus sp. , Aedokritus sp. Cladopelma forcipis, Cryptochironomus brasiliensis, Nilothauma sp.1 and Caladomyia sp. C, Tanytarsus sp. , Tanytarsus rhabdomantis and Chironomus gr. salinarius as potential indicators related with the spatiotemporal faunal distribution of Lake Figueira.

Fate and effects of clothianidin in fields using conservation practices.

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

2015-02-01

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

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

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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.

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

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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

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

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

1996-01-01

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

Do acid volatile sulfides (AVS) influence the accumulation of sediment-bound metals to benthic invertebrates under natural field conditions?

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De Jonge, Maarten; Dreesen, Freja; De Paepe, Josefina; Blust, Ronny; Bervoets, Lieven

2009-06-15

The present study evaluates the influence of acid volatile sulfides (AVS) on accumulation of sediment-bound metals in benthic invertebrates under natural field conditions. Natural sediments, pore water, surface water, and two species of widespread benthic invertebrates (Chironomus gr. thummi and Tubifex tubifex) were collected from 17 historical polluted Flemish lowland rivers and measured for metal concentrations. Different sediment characteristics were determined (AVS, organic matter, clay content) and multiple regression was used to study their relationship with accumulated metals in the invertebrates. Physical and chemical analysis of the field samples indicated low metal concentrations in the water and pore water, but very high metal concentrations in the sediment and the invertebrates, especially for Pb (5.99 micromol/ g). In general, metal accumulation in chironomids and tubificid worms was most strongly correlated with total metal concentrations in the sediment and sediment metal concentrations normalized for organic matter and clay content. Following the results of the linear regression model, AVS did not turn out to be a significant variable in describing variation in metal accumulation. Our study clearly demonstrates that, in addition to the results gained from experiments under lab conditions, benthic invertebrates can accumulate metals from unspiked field sediments even when there's an excess of AVS.

Rotavirus research in Amazon wild birds kept in captivity in the state of Pará, Brazi

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Monique Araújo Luz

2014-06-01

Full Text Available ABSTRACT. Luz M.A., Bezerra D.A., Silva R.R., Guerreiro A.N., Seixas L.S., Bastos R.K.G., Mascarenhas J. D’Arc P., Moraes C.C.G., Souza N.F. & Meneses A.M.C. [Rotavirus research in Amazon wild birds kept in captivity in the state of Pará, Brazil.] Pesquisa de rotavírus em aves silvestres da região amazônica mantidas em cativeiro no estado do Pará, Brasil. Revista Brasileira de Medicina Veterinária, 36(2:167-173, 2014. Instituto da Saúde e Produção animal na Amazônia, Universidade Federal Rural da Amazônia, Avenida Presidente Tancredo Neves, 2501, Montese, Belém, PA 66077-901, Brasil. E-mail: monique.luz@ufra.edu.br This study aimed to investigate rotavirus in wild birds kept in captivity at Pará State, to detect and characterize the electropherotypes groups of circulating rotaviruses and investigate A and D rotavirus groups presence in fecal specimens of these birds. Fecal samples were collected at Fazenda Paricuiã (Terra Alta / PA, Brazil, in Jardim Zoobotânico da Amazônia Bosque Rodrigues Alves, Parque Ecológico Mangal das Garças, Museu Paraense Emílio Goeldi (MPEG and Bioparque Amazônia Crocodilo Safari in Belém/Pará/Brazil, between March 2011 and February 2012. Were collected fecal samples from 83 birds belonging to the orders: Psittaciformes (Family Psittacidae, Ciconiformes (Ardeidae and Threskiornithidae families and Falconiformes (Family Accipitridae. Fecal suspensions were prepared from samples collected, with subsequent extraction of viral dsRNA, which was subjected to polyacrylamide gel electrophoresis (PAGE. Reverse transcription polymerase chain reaction (RT-PCR was performed with specific primers for amplification of NSP4 gene of A rotavirus and VP6 gene of D rotavirus. All samples were negative by both EGPA and by RT-PCR, requiring, however, further studies aimed in wild birds kept in captivity to determine the role of these species in the rotavirus epidemiology.

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

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

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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

Aspectos da reprodução e alimentação de Neoplecostomus microps (Loricariidae, Neoplecostominae na microbacia do Ribeirão Grande, serra da Mantiqueira oriental (Estado de São Paulo - DOI: 10.4025/actascibiolsci.v30i4.301 Reproduction and feeding aspects of Neoplecostomus microps (Loricariidae, Neoplecostominae in the Ribeirão Grande system, eastern Serra da Mantiqueira (São Paulo State - DOI: 10.4025/actascibiolsci.v30i4.301

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Ursulla Pereira Souza

2008-11-01

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 distribuídas em um ciclo anual. Neoplecostomus micropstem 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 de Coleoptera 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

Ecotoxicological impact of Zequanox®, a novel biocide, on selected non-target Irish aquatic species.

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Meehan, Sara; Shannon, Adam; Gruber, Bridget; Rackl, Sarahann M; Lucy, Frances E

2014-09-01

Effective, species-specific zebra mussel control is needed urgently for Ireland׳s freshwater bodies, which became infested with non-native zebra mussels in the 1990s. Zequanox®, a newly commercialized product for zebra and quagga mussel control, is composed of dead Pseudomonas fluorescens CL 145A cells. This paper describes ecotoxicology tests on three representative native Irish freshwater species: Anodonta (duck mussel), Chironomus plumosus (non-biting midge), and Austropotamobius pallipes (white-clawed crayfish). The species were exposed to Zequanox in a 72-h static renewal toxicity test at concentrations of 100-750mg active ingredient per liter (mga.i./L). Water quality parameters were measured every 12-24h before and after water and product renewal. After 72h, endpoints were reported as LC10, LC50, and LC100. The LC50 values derived were (1) Anodonta: ≥500mga.i./L (2) C. plumosus: 1075mga.i./L, and (3) A. pallipes: ≥750mga.i./L. These results demonstrate that Zequanox does not negatively affect these organisms at the concentration required for >80percent zebra mussel mortality (150mg a.i/L) and the maximum allowable treatment concentration in the United Sates (200mga.i./L). They also show the overall species-specificity of Zequanox, and support its use in commercial facilities and open waters. Copyright © 2014 Elsevier Inc. All rights reserved.

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

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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.

Trophic transfer of pyrene metabolites between aquatic invertebrates

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Carrasco Navarro, V.; Leppänen, M.T.; Kukkonen, J.V.K.; Godoy Olmos, S.

2013-01-01

The trophic transfer of pyrene metabolites was studied using Gammarus setosus as a predator and the invertebrates Lumbriculus variegatus and Chironomus riparius as prey. The results obtained by liquid scintillation counting confirmed that the pyrene metabolites produced by the aquatic invertebrates L. variegatus and C. riparius were transferred to G. setosus through the diet. More detailed analyses by liquid chromatography discovered that two of the metabolites produced by C. riparius appeared in the chromatograms of G. setosus tissue extracts, proving their trophic transfer. These metabolites were not present in chromatograms of G. setosus exclusively exposed to pyrene. The present study supports the trophic transfer of PAH metabolites between benthic macroinvertebrates and common species of an arctic amphipod. As some PAH metabolites are more toxic than the parent compounds, the present study raises concerns about the consequences of their trophic transfer and the fate and effects of PAHs in natural environments. - Highlights: ► The trophic transfer of pyrene metabolites between invertebrates was evaluated. ► Biotransformation of pyrene by L. variegatus and C. riparius is different. ► Metabolites produced by L. variegatus and C. riparius are transferred to G. setosus. ► Specifically, two metabolites produced by C. riparius were transferred. - Some of the pyrene metabolites produced by the model invertebrates L. variegatus and C. riparius are transferred to G. setosus through the diet, proving their trophic transfer.

The Role of Heme Chirality in the Circular Dichroism of Heme Proteins

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Woody, Robert W.; Pescitelli, Gennaro

2014-07-01

The rotational strength (R) of the Soret transition in sperm-whale myoglobin (SW Mb), the hemoglobin from Chironomus thummi thummi (CTT Hb), and human hemoglobin (hHb) has been calculated using 20 high-resolution ( Raro > Rpep. For CTT Hb and hHB, the orders were, respectively, Rint > Rpep > Raro and Rint > Raro ≈ Rpep. Human Hb ɑ chains showed the same trend as CTT Hb. Only in the hHb β chains did Raro predominate, with the order Raro > Rint > Rpep. The total predicted Rtot for SW Mb, CTT Hb, and hHb averaged +0.77±0.10 (0.56 - 0.80), -0.37±0.12 (-0.5), and +0.31±0.17 DBM (0.23 - 0.50), respectively. (Values in parentheses are experimental values.) Thus, contrary to the currently accepted view, coupling with aromatic side-chain or peptide transitions is not the dominant factor in the Soret circular dichroism (CD) of these proteins. The Soret CD is dominated by intrinsic CD of the heme chromophore, of which vinyl torsion is the major determinant. This result suggests an explanation for the large effect of heme isomerism on the Soret CD of Mb and Hb. Rotation about the ɑ-γ axis may be associated with large changes in vinyl torsion and thus substantially alter the intrinsic CD, even reversing its sign.

Dental remains of cebid platyrrhines from the earliest late Miocene of Western Amazonia, Peru: Macroevolutionary implications on the extant capuchin and marmoset lineages.

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Marivaux, Laurent; Adnet, Sylvain; Altamirano-Sierra, Ali J; Pujos, François; Ramdarshan, Anusha; Salas-Gismondi, Rodolfo; Tejada-Lara, Julia V; Antoine, Pierre-Olivier

2016-11-01

Undoubted fossil Cebidae have so far been primarily documented from the late middle Miocene of Colombia, the late Miocene of Brazilian Amazonia, the early Miocene of Peruvian Amazonia, and very recently from the earliest Miocene of Panama. The evolutionary history of cebids is far from being well-documented, with notably a complete blank in the record of callitrichine stem lineages until and after the late middle Miocene (Laventan SALMA). Further documenting their evolutionary history is therefore of primary importance. Recent field efforts in Peruvian Amazonia (Contamana area, Loreto Department) have allowed for the discovery of an early late Miocene (ca. 11 Ma; Mayoan SALMA) fossil primate-bearing locality (CTA-43; Pebas Formation). In this study, we analyze the primate material, which consists of five isolated teeth documenting two distinct Cebidae: Cebus sp., a medium-sized capuchin (Cebinae), and Cebuella sp., a tiny marmoset (Callitrichinae). Although limited, this new fossil material of platyrrhines contributes to documenting the post-Laventan evolutionary history of cebids, and besides testifies to the earliest occurrences of the modern Cebuella and Cebus/Sapajus lineages in the Neotropics. Regarding the evolutionary history of callitrichine marmosets, the discovery of an 11 Ma-old fossil representative of the modern Cebuella pushes back by at least 6 Ma the age of the Mico/Cebuella divergence currently proposed by molecular biologists (i.e., ca. 4.5 Ma). This also extends back to > 11 Ma BP the divergence between Callithrix and the common ancestor (CA) of Mico/Cebuella, as well as the divergence between the CA of marmosets and Callimico (Goeldi's callitrichine). This discovery from Peruvian Amazonia implies a deep evolutionary root of the Cebuella lineage in the northwestern part of South America (the modern western Amazon basin), slightly before the recession of the Pebas mega-wetland system (PMWS), ca. 10.5 Ma, and well-before the subsequent

Principais Acervos de Paleontologia do Brasil

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Eloisa Magalhães Pássaro

2014-07-01

Full Text Available O presente trabalho apresenta uma súmula dos principais acervos paleontológicos no Brasil, sem considerar instituições que por ora se encontram fechadas para reforma, com coleções predominantemente didáticas ou acadêmicas e acervos com menos de uma centena de exemplares catalogados. Das trinta instituições listadas, doze deles estão situadas no sudeste (Rio de Janeiro, Belo Horizonte, Peirópolis, Ouro Preto, São Paulo, Rio Claro, Taubaté e Monte Alto, dez no nordeste (Ceará, Rio Grande do Norte, Pernambuco, Sergipe e Bahia, cinco na região sul (Mafra, Porto Alegre, São Leopoldo e Santa Maria, duas na região norte (Acre e Pará e uma na região centro-oeste. Os maiores acervos de fósseis no Brasil se encontram no Museu de Ciências da Terra do DNPM e no Museu Nacional, ambos no Rio de Janeiro, que reúnem cerca de 260.000 exemplares, ainda que em Aracaju, Sergipe, esteja a terceira maior coleção paleontológica brasileira, com aproximadamente 38.000 fósseis pertencentes à Fundação Paleontológica Phoenix. A maioria dos acervos temáticos está relacionada a fósseis cretáceos, o que é concordante com a abundância de fósseis brasileiros desta idade: no nordeste, os acervos se destacam pelo grande número de invertebrados e peixes, e em Minas Gerais e São Paulo, pelos seus répteis. Outros acervos temáticos encontram-se no Rio Grande do Sul (répteis triássicos, São Paulo (icnofósseis mesozóicos, Santa Catarina (invertebrados paleozoicos, Ceará e Pernambuco (icnofósseis siluro-devonianos e Ceará, Bahia, Minas Gerais e Acre (megafauna cenozoica. Os museus mais antigos do Brasil com acervos paleontológicos são o Museu Nacional, criado em 1818 no Rio de Janeiro, o Museu Paraense Emílio Goeldi, aberto em 1866 em Belém, e o Museu de Ciência e Técnica da Escola de Minas de Ouro Preto, criado em 1884, todos centenários.

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

International Nuclear Information System (INIS)

Redman, S.; Janisch, T.

1995-01-01

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

The environmental state of Lake Ladoga sediments, Russia

International Nuclear Information System (INIS)

Pellinen, J.; Ristola, T.; Kukkonen, J.; Leppaenen, M.; Hoof, P.L. van; Robbins, J.A.

1994-01-01

The authors collected sediments in the summer 1993 from Lake Ladoga for chemical analyses and toxicity tests to assess the state of the lake. The sediments were analyzed for heavy metals, fluorides, chlorinated hydrocarbons, polyaromatic hydrocarbons, and certain radionuclides related to the fallout from the Chernobyl accident. In general, the concentrations of toxic chemicals were low. Most chemicals were below the limit of detection. The range of the total concentration of 17 PCB congeners was from 6 to 30 ng/kg dw; the highest value was at the pulp and paper mill located in the northeastern shore of the lake (Pitkaeranta). The highest concentrations of Cr, Co, Ni, Cu, Zn, Pb were 10, 42, 46, 36, 188, and 143 μg/g dw, respectively. Arsene was not detected at all and Cd only at one out of 12 sites studied. The toxicological testing with larvae of a midge, Chironomus riparius, and Daphnia magna resulted in only slight effects which may in part be related to different physical characteristics of the sediments rather than to toxic effects. The highest mortality was 75% at the deepest part of the lake (close to Valamo Island) which was believed to be the least polluted. The highest heavy metal concentrations and slow development of the larvae were observed for the same site. In the south of the lake at the Volhov Bay which receives effluents from forest and aluminum industry, the mortality was 10--50%

Resolving the false-negative issues of the nonpolar organic amendment in whole-sediment toxicity identification evaluations.

Science.gov (United States)

Mehler, W Tyler; Keough, Michael J; Pettigrove, Vincent

2018-04-01

Three common false-negative scenarios have been encountered with amendment addition in whole-sediment toxicity identification evaluations (TIEs): dilution of toxicity by amendment addition (i.e., not toxic enough), not enough amendment present to reduce toxicity (i.e., too toxic), and the amendment itself elicits a toxic response (i.e., secondary amendment effect). One such amendment in which all 3 types of false-negatives have been observed is with the nonpolar organic amendment (activated carbon or powdered coconut charcoal). The objective of the present study was to reduce the likelihood of encountering false-negatives with this amendment and to increase the value of the whole-sediment TIE bioassay. To do this, the present study evaluated the effects of various activated carbon additions to survival, growth, emergence, and mean development rate of Chironomus tepperi. Using this information, an alternative method for this amendment was developed which utilized a combination of multiple amendment addition ratios based on wet weight (1%, lower likelihood of the secondary amendment effect; 5%, higher reduction of contaminant) and nonconventional endpoints (emergence, mean development rate). This alternative method was then validated in the laboratory (using spiked sediments) and with contaminated field sediments. Using these multiple activated carbon ratios in combination with additional endpoints (namely, emergence) reduced the likelihood of all 3 types of false-negatives and provided a more sensitive evaluation of risk. Environ Toxicol Chem 2018;37:1219-1230. © 2017 SETAC. © 2017 SETAC.

Pyrethroid insecticides in urban salmon streams of the Pacific Northwest

Energy Technology Data Exchange (ETDEWEB)

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

2011-10-15

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

Pyrethroid insecticides in urban salmon streams of the Pacific Northwest

International Nuclear Information System (INIS)

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

2011-01-01

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

Inconsistency in the analysis of morphological deformities in chironomidae (Insecta: Diptera) larvae.

Science.gov (United States)

Salmelin, Johanna; Vuori, Kari-Matti; Hämäläinen, Heikki

2015-08-01

The incidence of morphological deformities of chironomid larvae as an indicator of sediment toxicity has been studied for decades. However, standards for deformity analysis are lacking. The authors evaluated whether 25 experts diagnosed larval deformities in a similar manner. Based on high-quality digital images, the experts rated 211 menta of Chironomus spp. larvae as normal or deformed. The larvae were from a site with polluted sediments or from a reference site. The authors revealed this to a random half of the experts, and the rest conducted the assessment blind. The authors quantified the interrater agreement by kappa coefficient, tested whether open and blind assessments differed in deformity incidence and in differentiation between the sites, and identified those deformity types rated most consistently or inconsistently. The total deformity incidence varied greatly, from 10.9% to 66.4% among experts. Kappa coefficient across rater pairs averaged 0.52, indicating insufficient agreement. The deformity types rated most consistently were those missing teeth or with extra teeth. The open and blind assessments did not differ, but differentiation between sites was clearest for raters who counted primarily absolute deformities such as missing and extra teeth and excluded apparent mechanical aberrations or deviations in tooth size or symmetry. The highly differing criteria in deformity assignment have likely led to inconsistent results in midge larval deformity studies and indicate an urgent need for standardization of the analysis. © 2015 SETAC.

Ecotoxicological effect characterisation of widely used organic UV filters

International Nuclear Information System (INIS)

Kaiser, D.; Sieratowicz, A.; Zielke, H.; Oetken, M.; Hollert, H.; Oehlmann, J.

2012-01-01

Chemical UV filters are used in sun protection and personal care products in order to protect consumers from skin cancer induced by ultraviolet (UV) radiation. The present study aims to evaluate the effects of three common UV filters butyl-methoxydibenzoylmethane (B-MDM) ethylhexyl-methoxycinnamate (EHMC) and octocrylene (OCR) on aquatic organism, focussing particularly on infaunal and epibentic invertebrates (Chironomus riparius, Lumbriculus variegatus, Melanoides tuberculata and Potamopyrgus antipodarum). Due to their life habits, these organism are especially affected by lipophilic substances. Additionally, two direct sediment contact assays utilising zebra fish (Danio rerio) embryos and bacteria (Arthrobacter globiformis) were conducted. EHMC caused a toxic effect on reproduction in both snails with lowest observed effect concentrations (LOEC) of 0.4 mg/kg (Potamopyrgus antipodarum) and 10 mg/kg (Melanoides tuberculata). At high concentrations sublethal effects could be observed for D. rerio after exposure to EHMC (NOEC 100 mg/kg). B-MDM and OCR showed no effects on any of the tested organism. - Highlights: ► Ecotoxicological effects of common used UV filters on aquatic invertebrates. ► Butyl-methoxydibenzoylmethane, ethylhexyl-methoxycinnamate, and octocrylene used. ► Sediment based test systems. ► Ethylhexyl-methoxycinnamate caused a toxic effect on reproduction in both snails. ► Other substances showed no effects on any of the tested organism. - Ethylhexyl-methoxycinnamate caused a toxic effect on reproduction in both snails. Butyl-methoxydibenzoylmethane and octocrylene showed no effects on any of the tested organism.

Estructura del macrobentos de la laguna de Paca, Junín

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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.

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.

Assessing caffeine as an emerging environmental concern using conventional approaches.

Science.gov (United States)

Moore, M T; Greenway, S L; Farris, J L; Guerra, B

2008-01-01

Organic wastewater contaminants, including pharmaceuticals, caffeine, and nicotine, have received increased scrutiny because of their detection in water bodies receiving wastewater discharge. Despite recent measurement in United States streams, caffeine's effect on freshwater organisms is not well documented. The present study measured caffeine's lethal and sublethal effects on the freshwater species, Ceriodaphnia dubia, Pimephales promelas, and Chironomus dilutus. These organisms, which are used in standard testing or effluent monitoring, were exposed to aqueous caffeine solutions under static exposure for 48 hours and daily renewed static exposure for 7 days. Averaged responses of 48-hour acute end points indicated that C. dubia was more sensitive to caffeine exposures (LC50 = 60 mg/L) than either P. promelas (LC50 = 100 mg/L) or C. dilutus (LC50 = 1,230 mg/L). Exposure-response slopes confirmed these findings (3% mortality/mg/L for C. dubia; 0.5% mortality/mg/L for P. promelas; and 0.07% mortality/mg/L for C. dilutus). Comparative 7-day responses between C. dubia and P. promelas (LC50 = 46 and 55 mg/L, respectively) were more similar than the broad range of acute values. Sublethal effects measured for caffeine exposure included impaired C. dubia reproduction (IC50 = 44 mg/L) and inhibited P. promelas growth (IC50 = 71 mg/L). According to the results of this study, combined with earlier studies reporting environmental concentrations and product half-lives, caffeine should pose negligible risk for most aquatic vertebrate and invertebrate organisms.

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.

Assessing effects of a mining and municipal sewage effluent mixture on fathead minnow (Pimephales promelas) reproduction using a novel, field-based trophic-transfer artificial stream.

Science.gov (United States)

Rickwood, Carrie J; Dubé, Monique G; Weber, Lynn P; Lux, Sarah; Janz, David M

2008-01-31

The Junction Creek watershed, located in Sudbury, ON, Canada receives effluent from three metal mine wastewater treatment plants, as well as a municipal wastewater (MWW) discharge. Effects on fish have been documented within the creek (decreased egg size and increased metal body burdens). It has been difficult to identify the cause of the effects observed due to the confounded nature of the creek. The objectives of this investigation were to assess the: (1) effects of a mine effluent and municipal wastewater (CCMWW) mixture on fathead minnow (FHM; Pimephales promelas) reproduction in an on-site artificial stream and (2) importance of food (Chironomus tentans) as a source of exposure using a trophic-transfer system. Exposures to CCMWW through the water significantly decreased egg production and spawning events. Exposure through food and water using the trophic-transfer system significantly increased egg production and spawning events. Embryos produced in the trophic-transfer system showed similar hatching success but increased incidence and severity of deformities after CCMWW exposure. We concluded that effects of CCMWW on FHM were more apparent when exposed through the water. Exposure through food and water may have reduced effluent toxicity, possibly due to increased nutrients and organic matter, which may have reduced metal bioavailability. More detailed examination of metal concentrations in the sediment, water column, prey (C. tentans) and FHM tissues is recommended to better understand the toxicokinetics of potential causative compounds within the different aquatic compartments when conducting exposures through different pathways.

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.

Acute toxicity of metals and reference toxicants to a freshwater ostracod, Cypris subglobosa Sowerby, 1840 and correlation to EC50 values of other test models

International Nuclear Information System (INIS)

Khangarot, B.S.; Das, Sangita

2009-01-01

The ostracod Cypris subglobosa Sowerby, 1840 static bioassay test on the basis of a 48 h of 50% of immobilization (EC 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 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 2 ) for 17 physicochemical properties of metals or metal ions and EC 50 s (as pM) were examined by linear regression analysis. The electronegativity, ionization potential, melting point, solubility product of metal sulfides (pK sp ), softness parameter and some other physicochemical characteristics were significantly correlated with EC 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 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.

Multi-scale approach to the environmental factors effects on spatio-temporal variability of Chironomus salinarius (Diptera: Chironomidae) in a French coastal lagoon

Science.gov (United States)

Cartier, V.; Claret, C.; Garnier, R.; Fayolle, S.; Franquet, E.

2010-03-01

The complexity of the relationships between environmental factors and organisms can be revealed by sampling designs which consider the contribution to variability of different temporal and spatial scales, compared to total variability. From a management perspective, a multi-scale approach can lead to time-saving. Identifying environmental patterns that help maintain patchy distribution is fundamental in studying coastal lagoons, transition zones between continental and marine waters characterised by great environmental variability on spatial and temporal scales. They often present organic enrichment inducing decreased species richness and increased densities of opportunist species like C hironomus salinarius, a common species that tends to swarm and thus constitutes a nuisance for human populations. This species is dominant in the Bolmon lagoon, a French Mediterranean coastal lagoon under eutrophication. Our objective was to quantify variability due to both spatial and temporal scales and identify the contribution of different environmental factors to this variability. The population of C. salinarius was sampled from June 2007 to June 2008 every two months at 12 sites located in two areas of the Bolmon lagoon, at two different depths, with three sites per area-depth combination. Environmental factors (temperature, dissolved oxygen both in sediment and under water surface, sediment organic matter content and grain size) and microbial activities (i.e. hydrolase activities) were also considered as explanatory factors of chironomid densities and distribution. ANOVA analysis reveals significant spatial differences regarding the distribution of chironomid larvae for the area and the depth scales and their interaction. The spatial effect is also revealed for dissolved oxygen (water), salinity and fine particles (area scale), and for water column depth. All factors but water column depth show a temporal effect. Spearman's correlations highlight the seasonal effect (temperature, dissolved oxygen in sediment and water) as well as the effect of microbial activities on chironomid larvae. Our results show that a multi-scale approach identifies patchy distribution, even when there is relative environmental homogeneity.

Colonization by Chironomidae larvae in decomposition leaves of Eichhornia azurea in a lentic system in Southeastern Brazil.

Science.gov (United States)

da Silveira, Lidimara Souza; Martins, Renato Tavares; da Silveira, Guilherme Augusto; Grazul, Richard Michael; Lobo, Danielle Pinheiro; Alves, Roberto da Gama

2013-01-01

The objective of this study was to analyze the colonization of Chironomidae (Diptera) larvae during the decomposition of Eichhornia azurea (Swartz) Kunth (Commelinales: Pontederiaceae) leaves in a lake in southeastern Brazil in two seasons of the year. The experiment was conducted from September to November 2007 and February to April 2008. In each period, 21 litter bags were used, each containing 10 g of dried leaves. Three bags were removed after 2, 5, 8, 12, 25, 45, and 65 days of colonization. The decomposition rate of the E. azurea leaves was rapid in both seasons, with no significant difference between them. The Chironomidae showed higher density than the other invertebrates. Goeldichironomus, Tonytarsus, and Corynoneura were the most abundant genera of Chironomidae. The invertebrate density increased during the experiment, differing within days but not between seasons. The faunal composition differed between the decomposition phases (initial and final), but did not differ between the seasons (dry and wet). The taxa Ablabesmyia, Caladomyia, Chironomus, Goeldichironomus, and Parachironomus were the most closely related to the final days of the experiment. Litter was the main food item found in the gut contents of the organisms of all the genera analyzed, both at the beginning and end of the decomposition. We believe that the feeding activity combined with the high larval density is an important factor contributing to the rapid decomposition of the E. azurea leaves. In conclusion, the succession process along the detritus chain of E. azurea was more important in structuring the assemblage of Chironomidae larvae than seasonal variations.

Chironomidae bloodworms larvae as aquatic amphibian food.

Science.gov (United States)

Fard, Mojdeh Sharifian; Pasmans, Frank; Adriaensen, Connie; Laing, Gijs Du; Janssens, Geert Paul Jules; Martel, An

2014-01-01

Different species of chironomids larvae (Diptera: Chironomidae) so-called bloodworms are widely distributed in the sediments of all types of freshwater habitats and considered as an important food source for amphibians. In our study, three species of Chironomidae (Baeotendipes noctivagus, Benthalia dissidens, and Chironomus riparius) were identified in 23 samples of larvae from Belgium, Poland, Russia, and Ukraine provided by a distributor in Belgium. We evaluated the suitability of these samples as amphibian food based on four different aspects: the likelihood of amphibian pathogens spreading, risk of heavy metal accumulation in amphibians, nutritive value, and risk of spreading of zoonotic bacteria (Salmonella, Campylobacter, and ESBL producing Enterobacteriaceae). We found neither zoonotic bacteria nor the amphibian pathogens Ranavirus and Batrachochytrium dendrobatidis in these samples. Our data showed that among the five heavy metals tested (Hg, Cu, Cd, Pb, and Zn), the excess level of Pb in two samples and low content of Zn in four samples implicated potential risk of Pb accumulation and Zn inadequacy. Proximate nutritional analysis revealed that, chironomidae larvae are consistently high in protein but more variable in lipid content. Accordingly, variations in the lipid: protein ratio can affect the amount and pathway of energy supply to the amphibians. Our study indicated although environmentally-collected chironomids larvae may not be vectors of specific pathogens, they can be associated with nutritional imbalances and may also result in Pb bioaccumulation and Zn inadequacy in amphibians. Chironomidae larvae may thus not be recommended as single diet item for amphibians. © 2014 Wiley Periodicals, Inc.

Is similar the distribution of Chironomidae (Diptera and Oligochaeta (Annelida, Clitellata in a river and a lateral fluvial area?

Directory of Open Access Journals (Sweden)

Daniela Aparecida Silveira Cesar

2017-05-01

Full Text Available Abstract Numerous factors may affect the pattern of distribution of benthic fauna in a river mouth region and, among the macroinvertebrates, Chironomidae and Oligochaeta are the most abundant groups and most tolerant to environmental changes. Aim The aim of this study was to evaluate the controlling factors of and a possible similarity between Chironomidae and Oligochaeta assemblies at two close sites, the mouth of the Guareí River into the Paranapanema River (São Paulo, Brazil and its lateral fluvial area. Methods Fauna samples were collected every three months during one year. Water physical and chemical variables and sediment variables were also determined in the same period. Results Both assemblies presented low density variability over time in the lateral area due to sediment characteristics and environmental factors. Taxa Caladomyia, Parachironomus, Pristina sp., Pristina osborni, Bothrioneurum and Opistocysta funiculus were recorded at this site. The Guareí River presented both greater temporal and spatial variations, attributed mainly to a reduction in the water level. Greater organism abundance, especially of Chironomus and Tubificinae, was observed in the river. Conclusions Dissimilarity in temporal and spatial distributions of Chironomidae and Oligochaeta was attributed to peculiar characteristics of the two study sites, a river channel and a lateral area. Reduction in the water level over the year was the main controlling factor of Chironomidae and Oligochaeta richness and density in the river. In the lateral area, the presence and abundance of certain taxa were determined by the nature of the sediment and water physical and chemical variables.

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.)

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)

Development of rearing and testing protocols for a new freshwater sediment test species: the gastropod Valvata piscinalis.

Science.gov (United States)

Ducrot, Virginie; Cognat, Claudine; Mons, Raphaël; Mouthon, Jacques; Garric, Jeanne

2006-03-01

This paper aimed at proposing rearing and testing protocols for Valvata piscinalis, a new potential species for sediment toxicity testing. Such tests were developed since this species reliably represents the bio/ecological characteristics of other gastropods. It may thus be representative of their sensitivity to chemicals. V. piscinalis was successfully cultured in our laboratory for six generations. Cultures provided a high productivity for a low working time and low costs. The tests conditions we proposed seemed to be relevant for the development of reliable tests with this species. Indeed, hatching probability of egg-capsules, as well as embryo, newborn and juvenile survival rates, were close to 100%. Moreover, growth rates and fecundity were significantly higher than in field and in other laboratory studies. Partial life-cycle tests on clean sediments were achieved for various feeding levels to determine survival, growth and reproduction patterns, ad libitum feeding level and life cycle parameters values. Ad libitum feeding levels for newborn, juveniles and adults were 0.1, 0.4 and 0.8 mg Tetramin/individual/working day. Growth tests with zinc-spiked sediments provided a no-effect concentration and a lowest effect concentration of respectively 200 and 624 mg zinc/kg dry sediment. Other growth tests on spiked sediments we ran at our laboratory with second, third and fourth instars larvae of Chironomus riparius pointed out that V. piscinalis was more sensible to zinc than the chironomid, which is a routine test species in ecotoxicology. According to these results, V. piscinalis is a promising candidate species for sediment toxicity testing.

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)

Effect of seed kernel aqueous extract from Annona squamosa against three mosquito vectors and its impact on non-target aquatic organisms

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Ravichandran Ramanibai

2016-09-01

Full Text Available Objective: To evaluate the toxicity of Annona squamosa (A. squamosa aqueous (physiological saline seed soluble extract and its control of mosquito population. Methods: Ovicidal, larvicidal and pupicidal activity of A. squamosa crude soluble seed kernel extract was determined according to World Health Organization. The mortality of each mosquito stage was recorded after 24 h exposured to plant material. Toxicity assay was used to assess the non-target organisms with different concentrations according to Organisation for Economic Co-operation and Development. Results: The aqueous solubilized extracts of A. squamosa elicit the toxicity against all stages of Aedes aegypti, Anopheles stephensi and Culex quinquefasciatus, and the LC50 values against stages of egg, 1st-4th larvae were (1.45 and 1.26–2.5 mg/mL, (1.12 and 1.19–2.81 mg/ mL and (1.80 and 2.12–3.41 mg/mL respectively. The pupicidal activity also brought forth amended activity against all three mosquitoes species, and the LC50 values were consider to be 3.19, 2.42 and 4.47 mg/mL. Ultimately there was no mortality observed from non-target organism of Chironomus costatus. Conclusions: Based on the findings of the study, it suggests that the use of A. squamosa plant extract can act as an alternate insecticidal agents for controlling target mosquitoes without affecting the non-target aquatic insect. Further investigation to identify the active compounds and their mechanisms of action is recommended.

Interactions among zebra mussel shells, invertebrate prey, and Eurasian ruffe or yellow perch

Science.gov (United States)

Kolar, C.S.; Fullerton, A.H.; Martin, K.M.; Lamberti, G.A.

2002-01-01

The exotic zebra mussel, Dreissena polymorpha, is established in all of the Laurentian Great Lakes and may affect benthivorous fishes by increasing the complexity of benthic substrates and changing energy flow patterns within the food web. Native yellow perch, Perca flavescens, and the nonindigenous Eurasian ruffe, Gymnocephalus cernuus, are benthivores that may compete for limited food resources. As ruffe spread to areas with more dense zebra mussel populations, the zone of interaction among zebra mussels, yellow perch, and ruffe will increase and intensify. In the laboratory, the effect of zebra mussel shells on the ability of these fishes to forage on amphipods (Gammarus pseudolimnaeus) and chironomids (Chironomus plumosus) was examined in light and darkness. In 12 h, ruffe consumed more amphipods than did similar-sized yellow perch, particularly in darkness on bare cobble, and in light within zebra mussels. Amphipods decreased activity more in the presence of ruffe than yellow perch. More amphipods were found in zebra mussel shells than in bare cobble, whether or not fish were present. In darkness, when ruffe consumed more amphipods on bare cobble, amphipods became more associated with zebra mussel shells. Although ruffe consumed more amphipods than yellow perch, perch consumed more chironomids than ruffe on bare cobble. The presence of zebra mussel shells altered the relative consumption of invertebrates in some substrate-light combinations. Experiments such as these help to improve understanding of the direct and indirect effects of predation between and among native and nonindigenous species that may exert structuring forces on the nearshore communities of the Great Lakes currently or in the future.

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

Science.gov (United States)

Barrios, Maria; Wolff, Marta

2011-10-10

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

Assessing condition of macroinvertebrate communities and bed sediment toxicity in the Rochester Embayment Area of Concern, New York, USA

Science.gov (United States)

Duffy, Brian; George, Scott D.; Baldigo, Barry P.; Smith, Alexander J.

2017-01-01

The United States 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 1972. The lowest reach of the Genesee River and the Rochester Embayment on Lake Ontario between Bogus Point and Nine Mile Point, including Braddock Bay, were designated as an Area of Concern (AOC) due to effects of contaminated sediments and physical disturbance on several beneficial uses. Following sediment remedial efforts and with conditions improving in the AOC, the present study was conducted to reevaluate the status of the benthic macroinvertebrate (benthos) beneficial use impairment (BUI). Benthic macroinvertebrate community assessments and 10-day Chironomus dilutus bioassays were used to test the hypotheses that sediments within the AOC were no more toxic than sediments from surrounding reference areas. The study was separated into three discrete systems (Genesee River, Lake Ontario, and Braddock Bay) and non-parametric analyses determined that a multimetric index of benthic macroinvertebrate community integrity was significantly higher at AOC sites compared to reference sites on the Genesee River and in Braddock Bay while AOC and reference sites on Lake Ontario did not differ significantly. Survival and growth of C. dilutus were also similar between AOC and reference sites for each system with the exception of significantly higher growth at reference sites on Lake Ontario. Results generally indicated that the condition of benthos and toxicity of sediment of the Rochester Embayment AOC are similar to or better than that in the surrounding area.

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

International Nuclear Information System (INIS)

Pusceddu, Fabio Hermes

2009-01-01

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 -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)

Chironomidae feeding habits in different habitats from a Neotropical floodplain: exploring patterns in aquatic food webs.

Science.gov (United States)

Butakka, C M M; Ragonha, F H; Train, S; Pinha, G D; Takeda, A M

2016-02-01

Ecological studies on food webs have considerably increased in recent decades, especially in aquatic communities. Because Chironomidae family are highly specious, occurring in almost all aquatic habitats is considered organisms-key to initiate studies on ecological relationships and trophic webs. We tested the hypothesis that the diversity of the morphospecies diet reflects differences on both the food items available among habitats and the preferences of larval feeding. We analyzed the gut content of the seven most abundant Chironomidae morphospecies of the different habitats from the Upper Paraná River. We categorized the food items found into algae, fungal spores, fragments of plants, algae and animal fragments and sponge spicules. We observed the algae predominance in the gut content of morphospecies from lakes. Considering the different regions from each lake, we registered the highest food abundance in the littoral regions in relation to the central regions. From the variety of feeding habits (number of item kinds), we classified Chironomus strenzkei, Tanytarsus sp.1, Procladius sp.1 as generalist morphospecies. We found a nested pattern between food items and Chironomidae morphospecies, where some items were common to all taxa (e.g., Bacillariophyceae algae, especially), while others were found in specific morphospecies (e.g., animals fragments found in Procladius sp.1). The algae represented the most percentage of gut contents of Chironomidae larvae. This was especially true for the individuals from littoral regions, which is probably due to the major densities of algae associated to macrophytes, which are abundant in these regions. Therefore, the feeding behavior of these morphospecies was generalist and not selective, depending only of the available resources.

Suitability of a Saccharomyces cerevisiae-based assay to assess the toxicity of pyrimethanil sprayed soils via surface runoff: comparison with standard aquatic and soil toxicity assays.

Science.gov (United States)

Gil, Fátima N; Moreira-Santos, Matilde; Chelinho, Sónia; Pereira, Carla; Feliciano, Joana R; Leitão, Jorge H; Sousa, José P; Ribeiro, Rui; Viegas, Cristina A

2015-02-01

The present study is aimed at evaluating whether a gene expression assay with the microbial eukaryotic model Saccharomyces cerevisiae could be used as a suitable warning tool for the rapid preliminary screening of potential toxic effects on organisms due to scenarios of soil and water contamination with pyrimethanil. The assay consisted of measuring changes in the expression of the selected pyrimethanil-responsive genes ARG3 and ARG5,6 in a standardized yeast population. Evaluation was held by assessing the toxicity of surface runoff, a major route of pesticide exposure in aquatic systems due to non-point-source pollution, which was simulated with a pyrimethanil formulation at a semifield scale mimicking worst-case scenarios of soil contamination (e.g. accident or improper disposal). Yeast cells 2-h exposure to the runoff samples led to a significant 2-fold increase in the expression of both indicator genes. These results were compared with those from assays with organisms relevant for the aquatic and soil compartments, namely the nematode Caenorhabditis elegans (reproduction), the freshwater cladoceran Daphnia magna (survival and reproduction), the benthic midge Chironomus riparius (growth), and the soil invertebrates Folsomia candida and Enchytraeus crypticus (survival and reproduction). Under the experimental conditions used to simulate accidental discharges into soil, runoff waters were highly toxic to the standard test organisms, except for C. elegans. Overall, results point out the usefulness of the yeast assay to provide a rapid preview of the toxicity level in preliminary screenings of environmental samples in situations of inadvertent high pesticide contamination. Advantages and limitations of this novel method are discussed. Copyright © 2014 Elsevier B.V. All rights reserved.

Effects of dietary esfenvalerate exposures on three aquatic insect species representing different functional feeding groups.

Science.gov (United States)

Palmquist, Katherine R; Jenkins, Jeffrey J; Jepson, Paul C

2008-08-01

Given the chemical properties of synthetic pyrethroids, it is probable that compounds, including esfenvalerate, that enter surface waters may become incorporated into aquatic insect food sources. We examined the effect of dietary esfenvalerate uptake in aquatic insects representing different functional feeding groups. We used three field-collected aquatic insect species: A grazing scraper, Cinygmula reticulata McDunnough (Ephemeroptera: Heptageniidae); an omnivorous filter feeder, Brachycentrus americanus Banks (Trichoptera: Brachycentridae); and a predator, Hesperoperla pacifica Banks (Plecoptera: Perlidae). Laboratory-cultured algae were preexposed for 24 h to esfenvalerate concentrations of 0, 0.025, 0.05, and 0.1 microg/L and provided to two C. reticulata age classes (small and final-instar nymphs). Reduction in small nymph growth was observed following three weeks of feeding on algae exposed to 0.05 and 0.1 microg/L of esfenvalerate, and the highest dietary exposure reduced egg production in final-instar nymphs. The diet for B. americanus and H. pacifica consisted of dead third-instar Chironomus tentans larvae preexposed for 24 h to esfenvalerate concentrations ranging between 0.1 and 1.0 microg/L. Consumption of larvae exposed to 0.5 to 1.0 microg/L of esfenvalerate caused case abandonment and mortality in B. americanus caddisfly larvae. Although H. pacifica nymphs readily consumed esfenvalerate-exposed larvae, no adverse effects were observed during the present study. Furthermore, no evidence of esfenvalerate-induced feeding deterrence was found in any of the species tested, suggesting that aquatic insects may not be able to distinguish between pyrethroid-contaminated and uncontaminated food sources. These findings indicate that feeding deterrence is not a factor in regulating aquatic insect dietary exposures to synthetic pyrethroids.

[Endoplasmic-mitochondrial Ca(2+)-functional unit: dependence of respiration of secretory cells on activity of ryanodine- and IP3 - sensitive Ca(2+)-channels].

Science.gov (United States)

Velykopols'ka, O Iu; Man'ko, B O; Man'ko, V V

2012-01-01

Using Clark oxygen electrode, dependence of mitochondrial functions on Ca(2+)-release channels activity of Chironomus plumosus L. larvae salivary glands suspension was investigated. Cells were ATP-permeabilized in order to enable penetration of exogenous oxidative substrates. Activation of plasmalemmal P2X-receptors (as well as P2Y-receptors) per se does not modify the endogenous respiration of salivary gland suspension. That is, Ca(2+)-influx from extracellular medium does not influence functional activity of mitochondria, although they are located along the basal part of the plasma membrane. Activation of RyRs intensifies endogenous respiration and pyruvate-malate-stimulated respiration, but not succinate-stimulated respiration. Neither activation of IP3Rs (via P2Y-receptors activation), nor their inhibition alters endogenous respiration. Nevertheless, IP3Rs inhibition by 2-APB intensifies succinate-stimulated respiration. All abovementioned facts testify that Ca2+, released from stores via channels, alters functional activity of mitochondria, and undoubtedly confirm the existence of endoplasmic-mitochondrial Ca(2+)-functional unit in Ch. plumosus larvae salivary glands secretory cells. In steady state of endoplasmic-mitochondrial Ca(2+)-functional unit the spontaneous activity of IP3Rs is observed; released through IP3Rs, Ca2+ is accumulated in mitochondria via uniporter and modulates oxidative processes. Activation of RyRs induces the transition of endoplasmic-mitochondrial Ca(2+)-functional unit to the active state, which is required to intensify cell respiration and oxidative phosphorylation. As expected, the transition of endoplasmic-mitochondrial Ca(2+)-functional unit to inactivated state (i. e. inhibition of Ca(2+)-release channels at excessive [Ca2+]i) limits the duration of signal transduction, has protective nature and prevents apoptosis.

Using aquatic macroinvertebrate species traits to build test batteries for sediment toxicity assessment: accounting for the diversity of potential biological responses to toxicants.

Science.gov (United States)

Ducrot, Virginie; Usseglio-Polatera, Philippe; Péry, T Alexandre R R; Mouthon, Jacques; Lafont, Michel; Roger, Marie-Claude; Garric, Jeanne; Férard, Jean-François

2005-09-01

An original species-selection method for the building of test batteries is presented. This method is based on the statistical analysis of the biological and ecological trait patterns of species. It has been applied to build a macroinvertebrate test battery for the assessment of sediment toxicity, which efficiently describes the diversity of benthic macroinvertebrate biological responses to toxicants in a large European lowland river. First, 109 potential representatives of benthic communities of European lowland rivers were selected from a list of 479 taxa, considering 11 biological traits accounting for the main routes of exposure to a sediment-bound toxicant and eight ecological traits providing an adequate description of habitat characteristics used by the taxa. Second, their biological and ecological trait patterns were compared using coinertia analysis. This comparison allowed the clustering of taxa into groups of organisms that exhibited similar life-history characteristics, physiological and behavioral features, and similar habitat use. Groups exhibited various sizes (7-35 taxa), taxonomic compositions, and biological and ecological features. Main differences among group characteristics concerned morphology, substrate preferendum and habitat utilization, nutritional features, maximal size, and life-history strategy. Third, the best representatives of the mean biological and ecological characteristics of each group were included in the test battery. The final selection was composed of Chironomus riparius (Insecta: Diptera), Branchiura sowerbyi (Oligochaeta: Tubificidae), Lumbriculus variegatus (Oligochaeta: Lumbriculidae), Valvata piscinalis (Gastropoda: Valvatidae), and Sericostoma personatum (Trichoptera: Sericostomatidae). This approach permitted the biological and ecological variety of the battery to be maximized. Because biological and ecological traits of taxa determine species sensitivity, such maximization should permit the battery to better account

Identification of threshold body burdens of metals for the protection of the aquatic ecological status using two benthic invertebrates

International Nuclear Information System (INIS)

Bervoets, Lieven; De Jonge, Maarten; Blust, Ronny

2016-01-01

In this study accumulated concentrations of As, Cd, Cr, Cu, Ni, Pb and Zn in two benthic invertebrate taxa, Chironomus sp. and Tubificidae are related to ecological responses expressed as changes in macro invertebrate communities. In addition critical body burdens were estimated above which ecological quality was always lower than a certain threshold. Data from existing studies on bioaccumulation of the metals in both taxa were combined with different biological water quality indices. For all metal-endpoint combinations threshold values could be calculated above which ecological quality was always low. Safe threshold body burdens could be estimated for both species for all metals although the data set was more extended for Chrionomus sp. with estimated threshold values being 65, 3.2, 10, 57, 6.5, 73 and 490 μg/g dw for As, Cd, Cr, Cu, Ni, Pb and Zn. This study demonstrated that metal accumulation in resistant species such as chironomids and tubificid worms have the potential to be used as predictors of ecological effects in aquatic ecosystems. However, the estimated threshold values have to be validated and supported by more lines of evidence before they can be used by regulators. - Highlights: • Chironomid larvae and Tubificid worms can be used to relate accumulated metals to ecological endpoints. • Ecological water quality, calculated with biotic indices, is always low at high accumulated metal concentrations. • Critical body burdens in chironomids and tubificds could be estimated for As, Cd, Cr, Cu, Ni, Pb and Zn. - Maximal body burdens of metals in two invertebrate species could be estimated above which ecological quality was always low.

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

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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.

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

Science.gov (United States)

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

2015-01-01

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

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

International Nuclear Information System (INIS)

Jonge, Maarten de; Vijver, Bart van de; Blust, Ronny; Bervoets, Lieven

2008-01-01

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

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. Copyright © 2016 Elsevier B

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

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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

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

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

2018-03-01

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

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

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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

Diversity and structure of Chironomidae communities in relation to water quality differences in the Swartkops River

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Odume, O. N.; Muller, W. J.

The Swartkops River is an important freshwater ecosystem in South Africa. But owing to its location, it suffers varying degrees of human induced impacts which include industrial and domestic effluent discharges, deforestation as well as agricultural land use which have negatively impacted on the water quality. Diversity and community composition of aquatic insects are frequently used to assess environmental water quality status. Chironomids occupy extremely varied biotopes. Their extraordinary ecological range and environmental sensitivity make them particularly useful for assessing and interpreting changes in water quality of aquatic ecosystems. The community structure of chironomid larvae was investigated at four sites in the Swartkops River and effects of different chemical and physical variables on their distribution were explored. Chironomid larvae were collected using the South African Scoring System version 5 (SASS5) protocol. A total of 26 taxa from four sampling sites in the Swartkops River were identified. Margalef’s species richness index, equitability, Shannon and Simpson diversity indices were highest at site 1 (reference site). The downstream sites contained 6-20 taxa compared to the 25 taxa at site 1. Site 1 was characterised by the subfamilies Orthocladiinae, Tanypodinae and the tribe Tanytarsini while the impacted sites were characterised by Orthocladiinae and Chironomini. Chironomus spp., Dirotendipes sp., Kiefferulus sp. and Tanypus sp. seemed to be tolerant to pollution, occurring in high abundance at sites 2, 3 and 4. In contrast, Polypedilum sp., Tanytarsus sp., Orthocladius sp., Cricotopus spp. and Ablabesmyia sp. appeared to be more sensitive taxa, being less common at the impacted sites (sites 2, 3 and 4). Five days biochemical oxygen demand, dissolved oxygen, electrical conductivity, orthophosphate-phosphorus and total inorganic nitrogen were among the important variables that determine the observed chironomid community structure

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

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Pramual, Pairot; Simwisat, Kusumart; Martin, Jon

2016-01-28

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.

Fear and loathing in the benthos: Responses of aquatic insect larvae to the pesticide imidacloprid in the presence of chemical signals of predation risk.

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Pestana, João L T; Loureiro, Susana; Baird, Donald J; Soares, Amadeu M V M

2009-06-28

The influence of interactions between pesticide exposure and perceived predation risk on the lethal and sub-lethal responses of two aquatic insects was investigated using the pesticide imidacloprid, and a combination of predator-release kairomones from trout and alarm substances from conspecifics. Laboratory experiments examined feeding and respiration rates of the caddisfly Sericostoma vittatum as well as the growth, emergence and respiration rates of the midge Chironomus riparius, exposed to sub-lethal concentrations of imidacloprid. The effects of the two stressors on burrowing behaviour of both species were also assessed. The results show significant effects of environmentally relevant concentrations of imidacloprid on all endpoints studied. Perceived predation risk also elicited sub-lethal effects in C. riparius and S. vittatum, the latter species being less responsive to predation cues. The effects of simultaneous exposure to both types of stressors were assessed using two different approaches: analysis of variance and conceptual models [concentration addition (CA) and independent action (IA)] normally used for the evaluation of contaminant mixture exposure. Both statistical approaches showed no significant interactions on responses in simultaneous exposures in the majority of parameters assessed with only a signification deviation from the reference CA and IA models being found for C. riparius respiration data contrary to the ANOVA results. Exposure to imidacloprid also compromised antipredator behavioural responses of both insect species, with potential negative consequences in terms of mortality from predation in the field. The results obtained demonstrate that natural and anthropogenic stressors can be treated within the same framework providing compatible data for modelling. For an improved interpretation of ecological effects it will be important to expand the mechanistic study of effects of combined exposure to pesticides and perceived predation risk

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

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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

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

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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. Copyright © 2016 Elsevier B.V. All rights reserved.

Trait-based modelling of bioaccumulation by freshwater benthic invertebrates.

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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)

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

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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.

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

Environmentally relevant concentrations of polyethylene microplastics negatively impact the survival, growth and emergence of sediment-dwelling invertebrates.

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Ziajahromi, Shima; Kumar, Anupama; Neale, Peta A; Leusch, Frederic D L

2018-05-01

Microplastics are a widespread environmental pollutant in aquatic ecosystems and have the potential to eventually sink to the sediment, where they may pose a risk to sediment-dwelling organisms. While the impacts of exposure to microplastics have been widely reported for marine biota, the effects of microplastics on freshwater organisms at environmentally realistic concentrations are largely unknown, especially for benthic organisms. Here we examined the effects of a realistic concentration of polyethylene microplastics in sediment on the growth and emergence of a freshwater organism Chironomus tepperi. We also assessed the influence of microplastic size by exposing C. tepperi larvae to four different size ranges of polyethylene microplastics (1-4, 10-27, 43-54 and 100-126 μm). Exposure to an environmentally relevant concentration of microplastics, 500 particles/kg sediment , negatively affected the survival, growth (i.e. body length and head capsule) and emergence of C. tepperi. The observed effects were strongly dependent on microplastic size with exposure to particles in the size range of 10-27 μm inducing more pronounced effects. While growth and survival of C. tepperi were not affected by the larger microplastics (100-126 μm), a significant reduction in the number of emerged adults was observed after exposure to the largest microplastics, with the delayed emergence attributed to exposure to a stressor. While scanning electron microscopy showed a significant reduction in the size of the head capsule and antenna of C. tepperi exposed to microplastics in the 10-27 μm size range, no deformities to the external structure of the antenna and mouth parts in organisms exposed to the same size range of microplastics were observed. These results indicate that environmentally relevant concentrations of microplastics in sediment induce harmful effects on the development and emergence of C. tepperi, with effects greatly dependent on particle size. Copyright

Comprehensive characterization of the acute and chronic toxicity of the neonicotinoid insecticide thiamethoxam to a suite of aquatic primary producers, invertebrates, and fish.

Science.gov (United States)

Finnegan, Meaghean C; Baxter, Leilan R; Maul, Jonathan D; Hanson, Mark L; Hoekstra, Paul F

2017-10-01

Thiamethoxam is a neonicotinoid insecticide used widely in agriculture to control a broad spectrum of chewing and sucking insect pests. Recent detection of thiamethoxam in surface waters has raised interest in characterizing the potential impacts of this insecticide to aquatic organisms. We report the results of toxicity testing (acute and chronic) conducted under good laboratory practices for more than 30 freshwater species (insects, molluscs, crustaceans, algae, macrophytes, and fish) and 4 marine species (an alga, a mollusc, a crustacean, and a fish). As would be anticipated for a neonicotinoid, aquatic primary producers and fish were the least sensitive organisms tested, with acute median lethal and effect concentrations (LC50/EC50) observed to be ≥80 mg/L in all cases, which far exceeds surface water exposure concentrations. Tested molluscs, worms, and rotifers were similarly insensitive (EC50 ≥ 100 mg/L), except for Lumbriculus sp., with an EC50 of 7.7 mg/L. In general, insects were the most sensitive group in the study, with most acute EC50 values insects (acute EC50 insects (EC50 > 5.5 mg/L). The most sensitive chronic response was for Chironomus riparius, with a 30-d no-observed-effect concentration (NOEC; emergence) of 0.01 mg/L. Observed toxicity to the tested marine organisms was comparable to that of freshwater species. We used the reported data to construct species sensitivity distributions for thiamethoxam, to calculate 5% hazard concentrations (HC5s) for acute data (freshwater invertebrates), and compared these with measured concentrations from relevant North American surface waters. Overall, based on acute toxicity endpoints, the potential acute risk to freshwater organisms was found to be minimal (likelihood of exceeding HC5s < 1%). Environ Toxicol Chem 2017;36:2838-2848. © 2017 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals, Inc. on behalf of SETAC. © 2017 The Authors. Environmental

Occupational allergy to aquarium fish food: red midge larva, freshwater shrimp, and earthworm. A clinical and immunological study.

Science.gov (United States)

Meseguer Arce, J; Villajos, I M Sánchez-Guerrero; Iraola, V; Carnés, J; Fernández Caldas, E

2013-01-01

Chironomids seem to be the main cause of occupational allergy to aquarium fish food. The aim of this study was to investigate the pattern of occupational sensitization to 3 different arthropod species used as components of aquarium fish food. The study sample comprised 8 workers from a fish food packing department. The control group comprised 40 atopic patients (20 of whom were allergic to mites). We performed prick tests with extracts of red midge larva (Chironomus thummi), freshwater shrimp (Gammarus species), earthworm (Tubifex species), and other arthropod species and a battery of common inhalant allergens. We measured peak expiratory flow rate (PEFR) and specific immunoglobulin (Ig) E and performed a methacholine challenge test, nasal challenge test, and immunoblotting. Cross-reactivity analyses were completed using immunoblotting and CAP inhibition. Prick test results were positive to red midge larvae in 7 patients (87.5%), Gammarus in 5 (62.5%), Tubifex in 3 (37.5%), and mites in 6 (75%). In the mite-allergic controls, 30% had positive prick test results to red midge larvae. PEFR decreased > or = 20% during the packing process in all patients, and in 1 patient it indicated a dual asthmatic response. Methacholine challenge test results were positive in all participants. Nasal challenge tests were performed in 4 patients, and the results were positive. Specific IgE to red midge larvae was detected in 62.5%, Gammarus in 50%, and Tubifex in 16%. Bands of approximately 14-15 kDa and 31 kDa were observed in Gammarus and red midge larvae extracts. Cross-reactivity assays demonstrated that Gammarus totally inhibited red midge larvae, while Tubifex did so partially. Dermatophagoides pteronyssinus showed very low inhibitory capacity. Aquarium fish food arthropods are potent allergens with an elevated prevalence of sensitization and variable degree of crossreactivity. This is the first report of occupational allergy to Tubifex. More data are necessary to identify and

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

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

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

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

Science.gov (United States)

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

2015-02-01

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

LEVEL OF TOXICITY WATER AREA «TULENIY» AS A RESULT OF BIOASSAY

Directory of Open Access Journals (Sweden)

A. F. Sokolsky

2014-01-01

Full Text Available Aim. To determine the toxicity of marine waters area " tuleniy ".Location. Area " tuleniy ".Methods. Determining the level of toxicity of marine waters area "seal" method for biological testing was conducted according tothe guidelines approved by the Ministry of natural resources (guidance on the definition of ..., 2002; Dolzhenko, 1978. Guide prepared by the Center for Russian register of hydraulic structures and the state water cadastre of the MNR of Russia jointly with specialists of the Institute Committee of Russia and the UNION of ecological problems of the Ministry of Ukraine. The basis of the proposed system of marine toxicity biotests based on the results of generalization of experimental research based on the problem of pollution of water bodies and numerous literature data, making it possible to identify features of the response of aquatic organisms of different taxonomic groups to toxic impurities of different nature and origin. Experimental studies were conducted on the culture of marine unicellular algae Phaeodactylum tricornutum on planktonic crustacea Acartia tonsa, the larvae of the chironomid Chironomus gr.salinarius and juvenile guppies Poecillia reticulata Peters.Results. Comparative analysis of the results of research from 2001 to 2006 showed no acute toxic effect on the test object zooplankton and phytoplanton.Main conclusions. Throughout the study period (2001-2003, 2005-2006, you must allocate the spring of 2002, when it was recorded,the average of the lowest five years of research, the level of toxicity of water for the analyzed area.Considering the results of biological testing of the surveyed area by periods, it should be noted that the average level of toxicity of the waters did not undergo significant changes and were on the same level, not exceeding 17,6% (table. 1. According to the classification shown in table 2, the water in the surveyed area is assessed as "non-toxic".

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

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

The influence of food quantity on metal bioaccumulation and reproduction in fathead minnows (Pimephales promelas) during chronic exposures to a metal mine effluent.

Science.gov (United States)

Ouellet, Jacob D; Dubé, Monique G; Niyogi, Som

2013-05-01

Metal mine effluents can impact fish in the receiving environment via both direct effects from exposure as well as indirect effects via food web. The main objective of the present study was to assess whether an indirect effect such as reduced food (prey) availability could influence metal accumulation and reproductive capacity in fish during chronic exposure to a metal mine effluent. Breeding pairs of fathead minnows (Pimephales promelas) were exposed to either reference water (RW) or an environmentally relevant metal mine effluent [45 percent process water effluent (PWE)] for 21 days and fed either low food quantities [LF (a daily ration of 6-10 percent body weight)] or normal food quantities [NF (a daily ration of 20-30 percent body weight)] in artificial stream systems. Fish in RW treatments were fed Chironomus dilutus larvae cultured in RW (Treatments: RW-NF or RW-LF), while fish in PWE treatments were fed C. dilutus larvae cultured in PWE (Treatments: PWE-NF or PWE-LF). Tissue-specific (gill, liver, gonad and carcass) metal accumulation, egg production, and morphometric parameters in fish were analyzed. Fathead minnows that were exposed to LF rations had significantly smaller body, gonad and liver sizes, and were in a relatively poor condition compared to fathead minnows exposed to NF rations, regardless of the treatment water type (RW or PWE) (two-way ANOVA; pmetal-contaminated food in the PWE-NF treatment, tissue metal accumulation pattern were almost similar between the PWE-NF and PWE-LF treatments, except for higher liver barium, cobalt and manganese concentrations in the latter treatment. This indicated that a higher food ration could help reduce the tissue burden of at least some metals and thereby ameliorate the toxicity of metal-mine effluents in fish. More importantly, cumulative egg production in fish was found to be lowest in the PWE-LF treatment, whereas fish egg production in the PWE-NF treatment was not impacted. Overall, these findings suggest

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

Energy Technology Data Exchange (ETDEWEB)

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

2016-04-15

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

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

International Nuclear Information System (INIS)

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

2016-01-01

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

Reconstructing the ecological impacts of eight decades of mining, metallurgical, and municipal activities on a small boreal lake in northern Canada.

Science.gov (United States)

Doig, Lorne E; Schiffer, Stephanie T; Liber, Karsten

2015-07-01

As a result of long-term metal mining and metallurgical activities, the sediment of Ross Lake (Flin Flon, MB, Canada) is highly contaminated with metals and other elements. Although the effluents likely were discharged into Ross Lake as early as the late 1920s, lake biophysical data were not collected until 1973, more than 4 decades after the onset of mining and municipal activities. The early influence of these activities on the ecology of Ross Lake is unknown, as are the effects of improvements to metallurgical effluent quality and discontinuation of municipal wastewater discharge into the lake's north basin. To address this knowledge gap, analyses typical of paleolimnological investigations were applied to cores of sediment collected in 2009 from the south basin of Ross Lake. Stratigraphic analyses of physicochemical sediment characteristics (e.g., the concentrations of metals and other elements, organic C, total N, and δ(13)C and δ(15)N values) and subfossil remains (diatoms, Chironomidae, Chaoborus, and Cladocera) were used to infer historical biological and chemical changes in Ross Lake. With the onset of mining activities, concentrations of various elements (e.g., As, Cr, Cu, Zn, and Se) increased dramatically in the sediment profile, eventually declining with improved tailings management. Nevertheless, concentrations of metals in recent sediments remain elevated compared with pre-industrial sediments. Constrained cluster analyses demonstrated distinct pre-industrial and postindustrial communities for both the diatoms and chironomids. The biodiversity of the postindustrial diatom assemblages were much reduced compared with the pre-industrial assemblages. The postindustrial chironomid assemblage was dominated by Chironomus and to a lesser extent by Procladius, suggesting that Ross Lake became a degraded environment. Abundances of Cladocera and Chaoborus were severely reduced in the postindustrial era, likely because of metals toxicity. Overall, improvements

Larval gut pH profile in pestiferous .i.Chironomus crassicaudatus./i. and .i.Glyptotendipes paripes./i. (Chironomidae: Diptera) in reference to the toxicity potential of .i.Bacillus thuringiensis./i. serovar .i.israelensis./i

Czech Academy of Sciences Publication Activity Database

Frouz, Jan; Lobinske, R.J.; Yaqub, A.; Ali, A.

2007-01-01

Roč. 23, č. 3 (2007), s. 355-358 ISSN 8756-971X Institutional research plan: CEZ:AV0Z60660521 Keywords : chironomidae larvae * gut pH * Bacillus thuringiensis serovar israelensis Subject RIV: EH - Ecology, Behaviour Impact factor: 0.706, year: 2007

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

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

International Nuclear Information System (INIS)

Lagauzere, S.

2008-06-01

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

Coupling geochemical and biological approaches to assess the availability of cadmium in freshwater sediment

Energy Technology Data Exchange (ETDEWEB)

Dabrin, Aymeric, E-mail: aymeric.dabrin@cemagref.fr; Durand, Cyrielle L.; Garric, Jeanne; Geffard, Olivier; Ferrari, Benoit J.D.; Coquery, Marina

2012-05-01

Sediments are considered as a sink for metals, and the assessment of metal bioavailability for benthic organisms represents a great challenge. Diffusive Gradient in Thin films (DGT), developed to measure labile metals in aquatic media, have more recently been applied to sediment. Nevertheless, few studies have determined the relation between measurements from DGT and bioaccumulation in different benthic organisms. The aim of our work was to determine if labile metal measured by DGT in sediment is representative of bioavailable metal for benthic organisms. We focused our work on Cd and chose to use the diversity of ecological traits from different organisms to better understand the measurement given by DGT. We exposed simultaneously DGT and 3 macroinvertebrates species (the chironomid, Chironomus riparius; the amphipod, Gammarus fossarum; the mudsnail, Potamopyrgus antipodarum) to a natural sediment Cd-spiked at environmental relevant concentrations. The nature of sediment-bound Cd was also determined by means of sequential extractions in order to better interpret DGT measurements. Cadmium concentrations were determined in DGT and in the 3 organisms after one week of exposure. Results provided by DGT indicated that Cd was poorly released from particulate phase to pore water, suggesting that Cd measured by DGT was representative of the pore water labile fraction. Sequential extractions showed that the percentage of Cd bound to carbonate fraction increased simultaneously with Cd-spiking level; hence, this Cd fraction was poorly reactive to supply DGT demand. Cadmium accumulation rates were similar between DGT measurements and P. antipodarum, suggesting that labile Cd in pore waters was representative of bioavailable Cd for this species. Cadmium accumulation rates in C. riparius were higher than in DGT, demonstrating that C. riparius can mobilize Cd bound to carbonate phase. G. fossarum showed the lowest Cd accumulation rates, suggesting that they were mainly exposed

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

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

International Nuclear Information System (INIS)

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

2010-01-01

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 (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 presented in this

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

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

International Nuclear Information System (INIS)

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

2011-01-01

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

Assessment of the acute toxicity of eutrophic sediments after the addition of calcium nitrate (Ibirité reservoir, Minas Gerais-SE Brazil: initial laboratory experiments

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H. Janke

Full Text Available This study evaluated the acute toxicity of sediment in a eutrophic reservoir after remediation with a calcium nitrate solution to retain phosphorus. The study involved microcosms of surface sediments and water from the sediment-water interface in the Ibirité reservoir. This reservoir, located in the vicinity of metropolitan Belo Horizonte (Minas Gerais, SE Brazil, is a water body that receives treated effluents from an oil refinery (REGAP-Petrobras, as well as high loads of untreated urban effluents from the city of Ibirité and surrounding areas and industrial effluents from a major industrial park. Incubation times of the treatment experiments were: t = 0, t = 5, t = 10, t = 25, t = 50, t = 85 and t = 135 days. One control microcosm and three treated microcosms were analysed in each time interval. Acute toxicity of water samples was assessed with Ceriodaphnia silvestrii Daday, 1902 and that of bulk sediment samples with Chironomus xanthus Rempel, 1939. Toxicity tests were carried out concomitantly with chemical analyses of dissolved inorganic nitrogen species (ammonia, nitrate and nitrite, sulfate and metals in the water samples of the microcosms. Acid volatile sulfides (AVS, simultaneously extracted metal (SEM and potentially bioavailable metal were analyzed in bulk sediment samples. Neither of the tested organisms showed toxicity in the control microcosm samples. The water column of the treated microcosm showed toxicity to C. silvestrii, starting at t = 10 days, while the sediment pore water toxicity started at t = 0 day. However, toxicity was found to decline from t = 85 days to t = 135 days. Sediments showed toxicity to C. xanthus during the entire experiment, except at the longest incubation time (t = 135 days. The overall results indicate that nitrate, which reached concentrations exceeding 1,200 mg N-NO3- L-1 in the sediment pore water of the treated microcosms, was most probably responsible for the toxicity of the samples. Although

Influence of elevated alkalinity and natural organic matter (NOM) on tissue-specific metal accumulation and reproductive performance in fathead minnows during chronic, multi-trophic exposures to a metal mine effluent.

Science.gov (United States)

Ouellet, Jacob D; Dubé, Monique G; Niyogi, Som

2013-09-01

Metal bioavailability in aquatic organisms is known to be influenced by various water chemistry parameters. The present study examined the influence of alkalinity and natural organic matter (NOM) on tissue-specific metal accumulation and reproductive performance of fathead minnows (Pimephales promelas) during environmentally relevant chronic exposures to a metal mine effluent (MME). Sodium bicarbonate (NaHCO3) or NOM (as commercial humic acid) were added to a Canadian MME [45 percent process water effluent (PWE)] in order to evaluate whether increases in alkalinity (3-4 fold) or NOM (~1.5-3mg/L dissolved organic carbon) would reduce metal accumulation and mitigate reproductive toxicity in fathead minnows during a 21-day multi-trophic exposure. Eleven metals (barium, boron, cobalt, copper, lithium, manganese, molybdenum, nickel, rubidium, selenium, and strontium) were elevated in the 45 percent PWE relative to the reference water. Exposure to the unmodified 45 percent PWE resulted in a decrease of fathead minnow egg production (~300 fewer eggs/pair) relative to the unmodified reference water, over the 21-day exposure period. Water chemistry modifications produced a modest decrease in free ion activity of some metals (as shown by MINTEQ, Version 3) in the 45 percent PWE exposure water, but did not alter the metal burden in the treatment-matched larval Chironomus dilutus (the food source of fish during exposure). The tissue-specific metal accumulation increased in fish exposed to the 45 percent PWE relative to the reference water, irrespective of water chemistry modifications, and the tissue metal concentrations were found to be similar between fish in the unmodified and modified 45 percent PWE (higher alkalinity or NOM) treatments. Interestingly however, increased alkalinity and NOM markedly improved fish egg production both in the reference water (~500 and ~590 additional eggs/pair, respectively) and 45 percent PWE treatments (~570 and ~260 additional eggs

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

Science.gov (United States)

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

2012-07-01

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

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

International Nuclear Information System (INIS)

Ferreira, Patricia Cunico

2015-01-01

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 -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

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

Seafloor mapping at Olkiluoto western coast of Finland

International Nuclear Information System (INIS)

Ilmarinen, K.; Leinikki, J.; Oulasvirta, P.

2009-02-01

explained by 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.)

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.)

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

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

Science.gov (United States)

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

2001-01-01

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

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

Science.gov (United States)

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

2015-01-01

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

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

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

Science.gov (United States)

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

2013-01-01

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