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Background: We have come across the plant secondary metabolites having pesticidal properties being used in the form of pesticides. In this study, we used one of newly available and plant metabolite used as pesticide in wide agricultural fields - Karanjin, obtained from seeds of plant Pongamia pinnata. Methods: The study was conducted during the month of March 2016 at the Department of Zoology, Osmania University. The fish common carp- Cyprinus carpio was exposed to sub-lethal concentration of karanjin i.e., 1/10th of 96 h LC50 value (0.28 ppm) for a period of 21 d. Moreover, at 24 h, 7 d, 14 d and 21 d, the peripheral blood of both control and exposed group fishes were studied for the presences of micronuclei and other nuclear abnormalities. Results: The micronuclei were completely absent, i.e., were not seen during the sub-lethal exposure period. There were seen nuclear abnormalities such as blebbed nuclei (BN), notched nuclei (NN), differently shaped nuclei (DSN), pear-shaped nuclei (PSN), circular nuclei (CN), lobed nuclei (LN) and Karyolysed nuclei (KN). The control group showed few nuclear abnormalities. Conclusion: During the sub-lethal exposure, as the days of exposure increased, the types of aberrations and their number also increased. [ABSTRACT FROM AUTHOR]

The zebrafish as a test organism enables the investigation of effects on a wide range of biological levels from molecular level to the whole-organism level. The use of fish embryos represents an attractive model for studies aimed at understanding toxic mechanisms and the environmental risk assessment of chemicals. In the present study, a zebrafish ( Danio rerio ) in vivo model was employed in order to assess the effects of two commonly used pesticides, the insecticide diazinon and the herbicide diuron, on zebrafish early life stages. Since it was previously established that diazinon and diuron cause effects at the whole-organism level, this study assessed the suborganismic responses to exposure to these pesticides and the enzymatic responses (biochemical level) and the gene expression changes (molecular level) were analyzed. Different exposure scenarios were employed and the following endpoints measured: acetylcholinesterase (AChE), carboxylesterase (CES), ethoxyresorufin-O-deethylase (EROD), glutathione-S-transferase (GST), catalase (CAT) and glutathione peroxidase (GPx) activities; and gene expressions of the corresponding genes: acetylcholinesterase ( ache ), carboxylesterase ( ces2 ), cytochrome P450 ( cyp1a ), glutathione-S-transferase ( gstp1 ), catalase ( cat ), glutathione peroxidase ( gpx1a ) and additionally glutathione reductase ( gsr ). Significant changes at both the biochemical and the molecular level were detected. In addition, different sensitivities of different developmental stages of zebrafish were determined and partial recovery of the enzyme activity 48 h after the end of the exposure was observed. The observed disparity between gene expression changes and alterations in enzyme activities points to the necessity of monitoring changes at different levels of biological organization. Different exposure scenarios, together with a comparison of the responses at the biochemical and molecular level, provide valuable data on the effects of diazinon and diuron on low organizational levels in zebrafish embryos and larvae. [ABSTRACT FROM AUTHOR]

Nile Tilapia, (Oreochromis niloticus L.,) is the most popular animal protein for Egyptian people due to their price and availability. Todays, a ll the production fish exposed to biotic and abiotic environmental stress, that cause huge damage for the fish and costumers. During the current research one common pesticide Lannat was used by different concentrations i.e. 0.8, 1.6 and 3.2 ppm, to investigate the possible genotoxic effect in aquatic organisms, measurement and alteration by the physico- chemical properties of DNA and isolated chromatin from liver tissue and finally, investigating the chromosomal aberrations in vivo induction of sister chromatid exchange (SCEs). This work was carried out at the faculty of Agriculture Saba Basha during the period 2016-2017. The results showed that Mitotic activity in the gills of the control group was higher than in kidneys. In treatments, cells of gills displayed lower mitotic activity compared with that of kidneys. Different mitotic aberrations were recorded with high doses of Lannat such as stickiness and ring chromosomes, deletion, fragments, and Robertsonian Centric Fusion (RCF). Lannat showed that it can induce macro-DNA damage. Lysis of nucleus was also observed. [ABSTRACT FROM AUTHOR]

The effects of 2 currently used commercial pesticide formulations on Pacific sockeye salmon ( Oncorhynchus nerka), from fertilization to emergence, were evaluated in a gravel-bed flume incubator that simulated a natural streambed. Embryos were exposed to atrazine at 25 µg/L (low atrazine) or atrazine at 250 µg/L (high atrazine) active ingredient (a.i.), and chlorothalonil at 0.5 µg/L (low chlorothalonil) or chlorothalonil at 5 µg/L a.i. (high chlorothalonil) and examined for effects on developmental success and timing, as well as physical and biochemical growth parameters. Survival to hatch was reduced in the high chlorothalonil group (55% compared with 83% in controls), accompanied by a 24% increase in finfold deformity incidence. Reduced alevin condition factor (2.9-5.4%) at emergence and elevated triglyceride levels were seen in chlorothalonil-exposed fish. Atrazine exposure caused premature hatch (average high atrazine time to 50% hatch [H50] = 100 d postfertilization [dpf]), and chlorothalonil exposure caused delayed hatch (high chlorothalonil H50 = 108 dpf; controls H50 = 102 dpf). All treatments caused premature emergence (average time to 50% emergence [E50]: control E50 = 181 dpf, low chlorothalonil E50 = 175 dpf, high chlorothalonil E50 = 174 dpf, high atrazine E50 = 175 dpf, low atrazine E50 = 174 dpf), highlighting the importance of using a gravel-bed incubator to examine this subtle, but critical endpoint. These alterations indicate that atrazine and chlorothalonil could affect survival of early life stages of sockeye salmon in the wild. Environ Toxicol Chem 2017;36:1354-1364. © 2017 SETAC [ABSTRACT FROM AUTHOR]

Pesticides can exert negative effects on aquatic organisms at very low concentrations. While several prey taxa are frequently used as models in ecotoxicology studies, there is little information about the pesticide-sensitivity of predators. We examined the effects of a frequently applied glyphosate-based herbicide on two common aquatic predators: larval Aeshna cyanea dragonflies and adult male Lissotriton vulgaris newts, which are top predators in ephemeral water bodies lacking fishes. We exposed predators to the herbicide for 18 days under laboratory conditions and measured potential effects on survival, activity, body mass and predatory activity. To maximize detectability of effects, we applied the herbicide at a concentration of 6.5 mg a. e. glyphosate/L, corresponding to the highest concentration expected in nature. Our results showed that the tested herbicide formulation did not have severe effects on any of the measured fitness-related traits. Results of the present study support the hypothesis that the tested species are insensitive to the herbicide and are able to fulfil their important ecological role of top-down regulation even in highly contaminated habitats. However, potential long-term or indirect effects of the herbicide on the fitness of aquatic predators remain unknown. [ABSTRACT FROM AUTHOR]

The widely used organotins have the potential to disrupt the endocrine system, but little is known of underlying mechanisms of azocyclotin toxicity in fish. The objective of the present study was to investigate the impact of azocyclotin on reproduction in zebrafish. Adult zebrafish were exposed to 0.09 and 0.45 μg/L azocyclotin for 21 days, and effects on steroid hormones and mRNA expression of the genes belonging to the hypothalamic–pituitary–gonad (HPG) axis were investigated. Mass spectrometry methodology was developed to profile steroids within the metabolome of the gonads. They were disrupted as a result of azocyclotin exposure. Alterations in the expression of key genes associated with reproductive endocrine pathways in the pituitary ( lhβ ), gonad ( cyp19a1a , cyp17a1 and 17β-hsd3 ), and liver ( vtg1, vtg2, cyp1a1, comt, ugt1a and gstp1 ) were correlated with significant reductions in estrogen in both sexes and increased testosterone in females. Azocyclotin-induced down-regulation of cyp19a1a in males suggested a reduction in the rate of estrogen biosynthesis, while up-regulation of hepatic cyp1a1 and comt in both sexes suggested an increase in estrogen biotransformation and clearance. Azocyclotin also induced change in the expression of 17β-hsd3 , suggesting increased bioavailability of 11-ketotestosterone (11-KT) in the blood. Furthermore, the down-regulation of lhβ expression in the brains of azocyclotin-exposed fish was associated with inhibition of oocyte maturation in females and retarded spermatogenesis in males. As a histological finding, retarded development of the ovaries was found to be an important cause for decreased fecundity, with down-regulation of vtg suspected to be a likely underlying mechanism. Additionally, relatively high concentrations of azocyclotin in the gonads may have directly caused toxicity, thereby impairing gametogenesis and reproduction. Embryonic or larval abnormalities occurred in the F1 generation along with accumulated burdens of azocyclotin in F1 eggs, following parental exposure. Overall, our results indicate that exposure to azocyclotin can impair reproduction in fish, and induce toxicity related abnormalities in non-exposed offspring. [ABSTRACT FROM AUTHOR]

Use of pesticides or insecticides can be highly toxic to aquatic life forms due to leaching and agricultural runoff, rains or flood. Fipronil (FP) is a GABA receptor inhibitor, while buprofezin (BPFN) is an insect growth regulator. Presently, we exposed groups of aquaria acclimated carp fish ( Cyprinus carpio ) for 96 h to sub-lethal concentrations of fipronil (400 μg L −1 ; 9.15 × 10 −7 mol L −1 ) and buprofezin (BPFN, 100 mg L −1 ; 1.072 × 10 −6 mol L −1 ) singly or in combination. The extent of damage was assessed at biochemical, hematological, molecular biological and histopathological level. Results obtained in treated fish were compared statistically with those of control non-treated fish and also among treatment groups. Significance level was p < 0.05. Compared to control, serum total protein and globulin concentrations decreased significantly ( p < 0.0001) in fish treated with FP; while albumin concentration remained unaltered with all treatments. Glucose concentration decreased significantly ( p < 0.002) in fish treated with FP. In contrast, combined FP + BPFN treatment and BPFN treatment caused insignificant elevation of glucose concentration. Hematological assessment demonstrated significant decrease in red blood cell and thrombocyte counts, hemoglobin concentration and hematocrit percent; while white blood cell count showed an increase in all treatment groups ( p < 0.0001). Blood smears from pesticide treated fish revealed aberrant erythrocyte morphologies which included necrosis, micronuclear formation and hyperchromatosis. DNA laddering assay carried out on whole blood demonstrated excessive smear formation in combined FP + BPFN and BPFN treatment groups but no smear formation was noticeable in FP treated fish. Compared to control, whole blood DNA content increased significantly in the combined FP + BPFN and BPFN treatment groups ( p < 0.001 and p < 0.009). With all treatments histopathological changes observed in the gills were: epithelial uplifting and necrosis of lamellae, lamellar atrophy, disruption of cartilaginous core, fusion and disorganization of lamellae and telangiectasia. In liver these were: karyorrhexis, hepatocellular hypertrophy, nuclear hypertrophy, melanomacrophage aggregates and central vein contraction, while in the kidney: deterioration of glomerulus and dilatation of Bowman’s space, dilatation of renal tubules, thyroidisation, altered tubular lumen, nuclear hypertrophy, cellular atrophy, and cellular necrosis were the outcome. Our study revealed that FP and BPFN produce highly toxic effects on fish when given in combination or singly. To our knowledge, this is the first report on toxicity caused by FP and BPFN in single and combined state. [ABSTRACT FROM AUTHOR]

This contribution aimed to characterize physicochemical and kinetic parameters of the brain cholinesterases (ChEs) from Parachromis managuensis and investigate the in vitro effects of pesticides and metal ions on its activity intending to propose as biomarker. This species is suitable for this investigation because (1) it was recently introduced in Brazil becoming invasive (no restrictions on capture) and (2) occupies the top of the food chain (being subject to bioaccumulation). The enzyme extract was exposed to 10 metal ions (Al 3+ , Ba 2+ , Cd 2+ , Cu 2+ , Hg 2+ , Mg 2+ , Mn 2+ , Pb 2+ , Fe 2+ and Zn 2+ ) and ChEs selective inhibitors (BW284c51, Iso-OMPA, neostigmine and serine). The extract was also incubated with organophosphate (dichlorvos) and carbamate pesticides (carbaryl and carbofuran). Inhibition parameters (IC 20 , IC 50 and ki) were determined. Selective inhibitors and kinetic parameters confirmed acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) -like as responsible for the ChE activities, most AChE. The IC 50 values for pesticides were: 1.68 μM (dichlorvos); 4.35 μM (carbaryl) and 0.28 μM (carbofuran). Most of the analyzed ions did not show significant effect at 1 mM ( p = 0.05), whereas the following ions inhibited the enzyme activity in the order: Hg 2+ > Cu 2+ > Cd 2+ > Zn 2+ . Mercury ion strongly inhibited the enzyme activity (IC 20 = 0.7 μM). The results about allow to conclude that P. managuensis brain AChE is a potential biomarker for heavy metals and pesticides under study, mainly for the carbamate carbofuran once it was capable to detect 6-fold lower levels than the limit concentration internationally recommended. [ABSTRACT FROM AUTHOR]

This work is devoted to the applications of the multiple linear regression (MLR), multilayer perceptron neural network (MLP NN) and projection pursuit regression (PPR) to quantitative structure–property relationship analysis of bioconcentration factors (BCFs) of pesticides tested on Bluegill ( Lepomis macrochirus ). Molecular descriptors of a total of 107 pesticides were calculated with the DRAGON Software and selected by inverse enhanced replacement method. Based on the selected DRAGON descriptors, a linear model was built by MLR, nonlinear models were developed using MLP NN and PPR. The robustness of the obtained models was assessed by cross-validation and external validation using test set. Outliers were also examined and deleted to improve predictive power. Comparative results revealed that PPR achieved the most accurate predictions. This study offers useful models and information for BCF prediction, risk assessment, and pesticide formulation. [ABSTRACT FROM AUTHOR]

Water is indispensable for all physiological processes that determine the natural, correct development of living organisms. The intense anthropogenic activity diminished water retention capacity and caused increasing pollution to an extent that often threatens public health (NIKONOROV, 1981). The production and use of pesticides is a serious threat to the hydrosphere, which receives large amounts of such chemical substances, because of the waste discharges from the factories of antiparasitic products or because of rainwaters that wash away these substances from the treated agricultural lands (MOHAN & ARDELEAN, 1993). The spread of pesticides has become global as they are present in all inland waters which, in the end, reach different seas and oceans (BREZEANU & SIMON-GRUIŢĂ, 2002). In case of water contaminated with pesticides, the environmental impact is mainly due to the bioconcentration and biomagnification capacity of pesticides in organisms (GAVRILESCU, 2008). The paper renders the results of the investigations referring to the modifications of certain physiological indices under the influence of the fungicide Antracol 70 WP (Propineb 70%) at two thermal thresholds. Temperature is one of the most important environmental factors the living organisms had to adapt to in order to maintain their vital functions at an optimum level (MIHAI & BREZEANU, 2013). Antracol is a contact organic fungicide from the dithiocarbamate group. It is toxic to fish and aquatic invertebrates (KIDD & JAMES, 1991). It produces thyroid cancer in laboratory animals (HASEGAWA et al., 1993). The investigations proved that the fungicide Antracol 70 WP has an inhibitory effect on the oxygen consumption and respiratory rate on the investigated fish species (Carassius gibelio Bloch); at the same time, it increased the number of erythrocytes and reduced the glycaemic level having a hypoglycaemic effect. The carried out experiments emphasized that the fungicide Antracol 70 WP is toxic to fish even at very low concentrations. [ABSTRACT FROM AUTHOR]

Ecotoxicological effects of industrial chemicals (Rig wash, Oil eater, Nalco, Glycol?) and pesticides (Propoxur, Deltamethrin, Atrazine, Furadan) on Tilapia guineensis (fish) and Aporrectodea longa (earthworms) were tested using the Organisation for Economic Cooperation and Development (OECD) # 203 and 207 protocols. The water and soil ratings indicate that the test chemicals were toxic to the organisms. The estimated 96 hour lethal concentration LC50 values for Rig wash, Oil eater, Nalco EC1304A/COT 505, Glycol, Propoxur, and Deltamethrin were 26.34±0.46, 6.02±0.30, 3.07±0.14, 1.31±0.01, 20.91±0 and 0.01±0 mg/l respectively. In the earthworm bioassay, the estimated 14-day LC50 values for Rigwash, Oil eater, Nalco EC1304A/COT 505, Glycol, Atrazine and Furadan were 80.05±3.5, 151.55±10.7, 172.63±14.2, 63.72±2.43, 4.97±0 and 0.29±0 mg/kg respectively. Safety factors are arbitrarily built in around the LC50 values in order to arrive at environmentally tolerable concentrations. The concentration of a chemical in the receiving environment should not exceed 10% of the LC50. The organisms exposed to the test chemicals showed significant difference when compared with the levels measured in the control group. The observed sensitivity of the test organisms to the chemicals indicates that adherence to standard safety limits/measures should be maintained during use and disposal of hazardous chemicals. This would ensure that the biotic components of the Nigerian Niger Delta ecosystem are prudently protected. [ABSTRACT FROM AUTHOR]

Atrazine (ATR) and chlorpyrifos (CPF) are widely used pesticides in agricultural practices throughout world. It has resulted in a series of toxicological and environmental problems, such as impacts on many non-target aquatic species, including fish. The spleen and head kidney in the bony fish are the major hematopoietic organs, and play a crucial part in immune responses. This study evaluated the subchronic effects of ATR and CPF on the mRNA and protein levels of HSP60, HSP70 and HSP90 in the immune organs of common carp and compared the acute and subchronic effects of ATR and CPF on the swimming speed (SS) of common carp. The results of acute toxicity tests showed that the 96 h-LC 50 of ATR and CPF for common carp was determined to be 2.142 and 0.582 mg/L, respectively. Meanwhile, acute and subacute toxicity of ATR and CPF in common carp resulted in hypoactivity. We also found that the mRNA and protein levels of HSP60, HSP70 and HSP90 genes were induced in the spleen and head kidney of common carp exposed to ATR and CPF in the subchronic toxicity test. Our results indicate that ATR and CPF are highly toxic to common carp, and hypoactivity in common carp by acute and subchronic toxicity of ATR and CPF may provide a useful tool for assessing the toxicity of triazine herbicide and organophosphorous pesticides to aquatic organisms. In addition, the results from the subchronic toxicity test exhibited that increasing concentration of ATR and CPF in the environment causes considerable stress for common carp, suggesting that ATR and CPF exposure cause immunotoxicity to common carp. [ABSTRACT FROM AUTHOR]

The objective of this study was to determine the levels of pesticides in the fishProchilodus costatuscaught in São Francisco River, one of most important rivers in Brazil. Thirty-six fish were captured in three different areas, and samples of the dorsal muscle and pooled viscera were collected for toxicological analysis. We evaluated the presence of 150 different classes of insecticides, fungicides, herbicides and acaricides by multiresidue analysis technique using liquid chromatography-tandem mass spectrometry (LC-MS/MS), with the limit of detection of 5 ppb. In this study, organophosphorus and carbamate pesticides were detected at the highest levels in the caught fish. Among the 41 organophosphorus pesticides surveyed, nine types were detected (chlorpyrifos, diazinon, dichlorvos, disulfoton, ethion, etrimfos, phosalone, phosmet and pyrazophos) in the muscle, viscera pool, or both in 22 (61.1%) fish. Sampled tissues of 20 (55.6%) fish exhibited at least one of the eight evaluated carbamate pesticides and their metabolites: aldicarb, aldicarb sulfoxide, carbaryl, carbofuran, carbosulfan, furathiocarb, methomyl and propoxur. Fungicides (carbendazim, benalaxyl, kresoxim-methyl, trifloxystrobin, pyraclostrobin and its metabolite BF 500 pyraclostrobin), herbicides (pyridate and fluasifopp-butyl), acaricide (propargite) and pyrethroid (flumethrin) were also detected. In conclusion,P. costatusfish caught in the São Francisco River contained residues of 17 different pesticides, in both muscles and the viscera pool, indicating heavy environmental contamination by pesticides in the study area. [ABSTRACT FROM AUTHOR]

Indicators are used to quantify the pressure of pesticides on the environment. Pesticide risk indicators typically require weighting environmental exposure by a no effect concentration. An indicator based on spread equivalents (ΣSeq) is used in environmental policy in Flanders (Belgium). The pesticide risk for aquatic life is estimated by weighting active ingredient usage by the ratio of their maximum allowable concentration and their soil halflife. Accurate estimates of total pesticide usage in the region are essential in such calculations. Up to 2012, the environmental impact of pesticides was estimated on sales figures provided by the Federal Government. Since 2013, pesticide use is calculated based on results from the Farm Accountancy Data Network (FADN). The estimation of pesticide use was supplemented with data for non-agricultural use based on sales figures of amateur use provided by industry and data obtained from public services. The Seq-indicator was modified to better reflect reality. This method was applied for the period 2009-2012 and showed differences between estimated use and sales figures of pesticides. The estimated use of pesticides based on accountancy data is more accurate compared to sales figures. This approach resulted in a better view on pesticide use and its respective environmental impact in Flanders. [ABSTRACT FROM AUTHOR]

In this article, the author discusses effect of contaminants including certain pesticides, pharmaceuticals, and industrial compounds on fishes and reflects on researchers efforts to fight against multifaceted problem of ecotoxicology.

Endosulfan is an organochlorine pesticide commonly found in aquatic environments that has been found to reduce thermal tolerance of fish. Lipotropes such as the food additive, Lecithin has been shown to improve thermal tolerance in fish species. This study was conducted to evaluate the role of lipotropes (lecithin) for enhancing the thermal tolerance of Chanos chanos reared under sublethal low dose endosulfan-induced stress. Two hundred and twenty-five fish were distributed randomly into five treatments, each with three replicates. Four isocaloric and isonitrogenous diets were prepared with graded levels of lecithin: normal water and fed with control diet (En0/L0), endosulfan-treated water and fed with control diet (En/L0), endosulfan-treated water and fed with 1% (En/L1%), 1.5% (En/L 1.5%) and 2% (En/L 2%) lecithin supplemented feed. The endosulfan in treated water was maintained at the level of 1/40th of LC 50 (0.52 ppb). At the end of the five weeks, critical temperature maxima (CTmax), lethal temperature maxima (LTmax), critical temperature minima (CTmin) and lethal temperature minima (LTmin) were Determined. There was a significant ( P <0.01) effect of dietary lecithin on temperature tolerance (CTmax, LTmax, CTmin and LTmin) of the groups fed with 1, 1.5 and 2% lecithin-supplemented diet compared to control and endosulfan-exposed groups. Positive correlations were observed between CT max and LTmax ( R 2 =0.934) as well as between CTmin and LTmin ( R 2 =0.9313). At the end of the thermal tolerance study, endosulfan-induced changes in cellular stress enzymes (Catalase, SOD and GST in liver and gill and neurotansmitter enzyme, brain AChE) were significantly ( p <0.01) improved by dietary lecithin. We herein report the role of lecithin in enhancing the thermal tolerance and protection against cellular stress in fish exposed to an organochlorine pesticide. [ABSTRACT FROM AUTHOR]

Pesticides are widely used in modern agriculture to aid in the production of high quality food. However, some pesticides have the potential to cause serious health and/or environmental damage. Organophosphates (OCP'S) and carbamates can cause pollution in freshwater ecosystem, as well as having a significant effect on the health of fish. The acute effects of commercial formulation of triazophos, profenofos, carbofuran and carbaryl were determined in one of the indigenous fish species, Catla catla fingerlings. Pesticides were applied to fingerlings that had been grown under optimised standard conditions under a maintained static bioaßay system. Probit analysis was used for the estimation of LC50 values, which were ascertained as 4.84, 0.19, 0.99 and 7.89 mg/L for triazophos, profenofos, carbofuran and carbaryl, respectively. 100% mortality of Catla catla was observed with a 2.8 mg/L dose of carbofuran at 96 hours with a significant difference. Acute toxic streß was noticed with subjects exhibiting behavioral intoxication, including suffocation, lying on the bottom, erratic swimming, lethargy and downward movements and gulping prior to mortality. [ABSTRACT FROM AUTHOR]

The article provides assessment of the presence of pesticides in the U.S. streams and rivers from 1992-2011 and compares them to previously reported findings from 1992-2001. Topics discussed include use of herbicides and fungicides to increase crop production and reduce insect-borne disease, adverse effects of pesticides on aquatic life and presence of insecticides atrazine, diazinon and malathion in rivers.

The present study was performed to investigate the impact of sublethal concentrations of malathion on different behavioural aspects of Heteropneustes fossilis. LC50 of malathion for 96 hrs by static bioassay test was found to be 21.34 μl/L .The fishes were exposed to three different sublethal concentrations (2.13μl/L, 1.07 μl/L and 0.71 μl/L) for 21 days. Malathion exposure caused decrease in resting period, increase in opercular movement and air gulping, increase in S-jerk, threat and burst swimming behaviour. Slow response during feeding, swimming on the upper surface of water hanging vertically, spreading throughout aquarium was also observed in pesticide treated fishes. In the highest concentration i.e. 2.13μl/L mortality of fishes occurred. Fishes died with bending of the mid section of the body and opening mouth. Fishes lay down motionless at the bottom of the aquarium before death. Fading of body colour was also observed in malathion treated fishes. These results suggest that sublethal concentrations of malathion has negative impact on the behavior of Heteropneustes fossilis. [ABSTRACT FROM AUTHOR]

Pesticides are frequently detected in urban streams, with concentrations often exceeding those reported in surface waters within agricultural areas. The authors studied growth, survival, and return rates of coho salmon ( Oncorhynchus kisutch) smolts exposed to a pesticide mixture ('cocktail') representative of the pesticides most frequently reported within urban streams in western Washington State, USA, in fall through early spring. Exposure concentrations were selected to represent a reasonable worst-case scenario based on field monitoring data. Smolts were continuously exposed to pulses of the cocktail either from fertilization through swim-up (2007-2008) or from fertilization through smoltification (2007-2008 and 2008-2009), coded wire tagged, and released in 2008 and 2009. Pre-release endpoints (growth, survival, sex ratio, brain acetylcholinesterase activity, and gonado- and hepatosomatic indices) were not affected. However, the number of returning adults exposed to the cocktail to swim-up (0.90%, n = 42) was more than double that of unexposed controls (0.38%, n = 26) in 2008, whereas in 2009, fish exposed through smoltification returned in lower numbers (0.15%, n = 18) than controls (0.37%, n = 30). Variability in return rates among treatments between years was comparable to that observed in previous whole life cycle studies with Pacific salmon and other contaminants. Results suggest that exposure to pesticides in urban streams does not directly impair early life stages of coho salmon, and that additional studies incorporating releases of larger numbers of smolts across several years are necessary to adequately quantify effects on return rates. Environ Toxicol Chem 2014;33:???-???. © 2014 SETAC [ABSTRACT FROM AUTHOR]

Highlights: [•] Matrix modelling for 21 potentially exposed fish species to pesticides showed that: [•] One least resilient fish species to all types of pesticide stress does not exist. [•] European minnow populations were the least resilient to reduction in fertility. [ • ] Northern pike populations were the least resilient to increased adult mortality. [ • ] European brook lamprey populations were the least resilient to increased juvenile mortality. [Copyright &y& Elsevier]

The decline of freshwater fish biodiversity corroborates the trends of unsustainable pesticide usage and increase of disease incidence in the last few decades. Little is known about the role of nonlethal exposure to pesticide, which is not uncommon, and concurrent infection of opportunistic pathogens in species decline. Moreover, preventative measures based on current knowledge of stress biology and an emerging role for epigenetic (especially methylation) dysregulation in toxicity in fish are lacking. We herein report the protective role of lipotropes/methyl donors (like choline, betaine and lecithin) in eliciting primary (endocrine), secondary (cellular and hemato-immunological and histoarchitectural changes) and tertiary (whole animal) stress responses including mortality (50%) in pesticide-exposed (nonlethal dose) and pathogen-challenged fish. The relative survival with betaine and lecithin was 10 and 20 percent higher. This proof of cause-and-effect relation and physiological basis under simulated controlled conditions indicate that sustained stress even due to nonlethal exposure to single pollutant enhances pathogenic infectivity in already nutritionally-stressed fish, which may be a driver for freshwater aquatic species decline in nature. Dietary lipotropes can be used as one of the tools in resurrecting the aquatic species decline. [ABSTRACT FROM AUTHOR]

Abstract: The pesticide 3-trifluoromethyl-4-nitrophenol (TFM) is used to control sea lamprey (Petromyzon marinus) populations in the Great Lakes through its application to nursery streams containing larval sea lampreys. TFM uncouples oxidative phosphorylation, impairing mitochondrial ATP production in sea lampreys and rainbow trout (Oncorhynchus mykiss). However, little else is known about its sub-lethal effects on non-target aquatic species. The present study tested the hypotheses that TFM exposure in hard water leads to (i) marked depletion of energy stores in metabolically active tissues (brain, muscle, kidney, liver) and (ii) disruption of active ion transport across the gill, adversely affecting electrolyte homeostasis in trout. Exposure of trout to 11.0mgl−1 TFM (12-h LC50) led to increases in muscle TFM and TFM-glucuronide concentrations, peaking at 9h and 12h, respectively. Muscle and brain glycogen was reduced by 50%, while kidney and muscle lactate increased with TFM exposure. Kidney ATP and phosphocreatine decreased by 50% and 70%, respectively. TFM exposure caused no changes in whole body ion (Na+, Cl−, Ca2+, K+) concentrations, gill Na+/K+ ATPase activity, or unidirectional Na+ movements across the gills. We conclude that TFM causes a mismatch between ATP supply and demand in trout, leading to increased reliance on glycolysis, but it does not have physiologically relevant effects on ion balance in hard water. [Copyright &y& Elsevier]

Highlights: [•] Forty currently used pesticides were analyzed in fish by QuEChERS coupled with LC-MS/MS. [•] Up to 23 pesticides were found along the Júcar River in fish and water samples. [•] Eight pesticides, some of them forbidden in the EU, were in water. [•] Most pesticides detected related to crop and livestock treatments in the floodplains. [•] Different degrees of bio-concentration in fish, depending on the species and compound. [ABSTRACT FROM AUTHOR]

Highlights: [•] Fish exposed to insecticides combination showed a differential physiologic profile. [•] Insecticides in combination provoked lipid oxidative damage in several tissues. [•] The multi-biomarker approach was useful to assess the toxicity of pesticides in fish. [•] The set of selected biomarkers was able to separate treatments. [•] Pesticides in combination produced deleterious effects on fish health. [Copyright &y& Elsevier]

Diazinon is a commonly used pesticide and its existence in the fresh water reservoirs of Pakistan has been reported by some authors. A semistatic experiment was conducted to find out the acute toxicity of diazinon as an aquatic pollutant on some hematological parameters of Indian carp (Cirrhinus mrigala). The 1, 24, 48, 72, and 96 h LC50 values of diazinon for Indian carp were estimated as 17.32 mg/L, 15.39 mg/L, 12.64 mg/L, 10.98 mg/L, and 8.15 mg/L respectively. A significant increase in the number of dead fish was observed as the concentration of diazinon and exposure time increased (P < 0.05). The results after acute exposure to 8.15 mg/L of diazinon for 96 h showed that compared to the control fish, the total erythrocytes, leukocytes, hemoglobin, and hematocrit values decreased significantly (P < 0.05) in exposed fish. The mean corpuscular volume and mean corpuscular hemoglobin increased significantly (P < 0.05), while the mean corpuscular hemoglobin concentration of both groups remained unchanged during the study. In conclusion, acute exposure to LC50 values of diazinon induced hematological alterations in Indian carp and offers a tool to evaluate toxicity derived alterations. [ABSTRACT FROM AUTHOR]

The aim of this study was to estimate the residue of chlorinated pesticides in the edible fish caught in the Gulf of Gdańsk and in the Vistula Lagoon. The highest mean concentrations of total DDT were found in the muscles of salmon (331.45 ng g lw.) and sabre carp (306.29 ng g lw.) caught in the Vistula Lagoon, and in the muscles of cod (309.88 ng g lw.) and herring (304.86 ng g lw.) from the Gulf of Gdańsk. Moreover, it was discovered that the following were present in the muscles of fish: DDT metabolites (pp'-DDE and pp'-DDD isomers) as well as hexachlorobenzene and its metabolites and endrin, dieldrin, α-endosulfan isomers and methoxychlor. Pesticides concentrations were higher in the livers of fish than in the muscles, which proves that the removal of toxins from the fish systems dominates over their accumulation. Because no concentration limits for pesticides have been defined, consumer safety assessment of fish caught in the Southern Baltic and in the Vistula Lagoon is not possible. The authors, having observed an increase in heksachlorobenzen in fish tissues suggested the existence of contemporary sources of pesticides which introduce them into the coastal zone. [ABSTRACT FROM AUTHOR]

Abstract: Fish are often exposed to various molecules like pesticides. Some of these compounds get biomagnified within aquatic food web, inducing health hazards of consumers. However, behaviors of many pesticides are still unknown. This work aims to study the uptake and the elimination of some of them in muscle tissue of edible fish (azoxystrobin, clomazone, diflufenican, dimethachlor, carbendazim, iprodion, isoproturon, mesosulfuron-methyl, metazachlor, napropamid, quizalofop, and thifensulfuron-methyl). Two freshwater fish species (Perca fluviatilis and Cyprinus carpio) were exposed to a mixture of these 13 pesticides, via multi-contaminated pellets, and then, eliminated. Compounds were measured in food, water and muscle tissue using multi-residues methods. Kinetics, biomagnification factors (BMFs) and half-lives (t1/2) were estimated and they did not show a large difference between the species. Muscular BMFs ranged from 2×10−6 (mesosulfuron-methyl in perch) to 1×10−3 (isoproturon and napropamid in perch) and t1/2 ranged from 0.8 (mesosulfuron-methyl in perch) to 40.3d (napropamid in carp). BMFs were also modeled as a function of K ow value. All BMF values were explained by the model, except for diflufenican which had a BMF lower than that expected by our modeling work, probably due to an efficient metabolism. Results led to the conclusion that none of these chemicals would probably be biomagnified within aquatic food webs. [Copyright &y& Elsevier]

The OECD test guideline 203 for determination of fish acute toxicity requires substantial numbers of fish and uses death as an apical end point. One potential alternative are fish cell lines; however, several studies indicated that these appear up to several orders of magnitude less sensitive than fish. We developed a fish gill cell line-based (RTgill-W1) assay, using several measures to improve sensitivity. The optimized assay was applied to determine the toxicity of 35 organic chemicals, having a wide range of toxicity to fish, mode of action and physicochemical properties. We found a very good agreement between in vivo and in vitro effective concentrations. For up to 73% of the tested compounds, the difference between the two approaches was less than 5-fold, covering baseline toxicants but as well compounds with presumed specific modes of action, including reactivity, inhibition of acetylcholine esterase or uncoupling of oxidative phosphorylation. Accounting for measured chemical concentrations eliminated two outliers, the hydrophobic 4-decylaniline and the volatile 2,3-dimethyl-1,3-butadiene, with an outlier being operationally defined as a substance showing a more than 10-fold difference between in vivo/in vitro effect concentrations. Few outliers remained. The most striking were allyl alcohol (2700-fold), which likely needs to be metabolically activated, and permethrin (190-fold) and lindane (63-fold), compounds acting, respectively, on sodium and chloride channels in the brain of fish. We discuss further developments of this assay and suggest its use beyond predicting acute toxicity to fish, for example, as part of adverse outcome pathways to replace, reduce, or refine chronic fish tests. [ABSTRACT FROM AUTHOR]

Twelve widely used pesticides were selected to investigate possible chemical, biological and toxicological effects of expired pesticides that may enter into our ecosystem. The selected compounds were tested for acute toxicity to Catla catla under static condition. Five to six concentrations (ranges from 0.005 - 80 mg I/1) of both expired and unexpired pesticide formulations were tested along with controls under similar conditions. The results of the LC50 (Lethal Concentration) demonstrated lower LC50 values for the expired pesticides as compared to the corresponding unexpired counter part. From this data, it is clear that expired pesticide formulations must be disposed carefully and care should be taken to avoid their discharge to water bodies and thus prevent loss to fish. [ABSTRACT FROM AUTHOR]

To evaluate the potential role of endocrine disruption in the decline of pelagic fishes in the San Francisco Bay Delta of California, various surface water samples were collected, extracted, and found to elicit estrogenic activity in laboratory fish. Chemical analysis of the estrogenic samples indicated 2 pesticides (bifenthrin, diuron), 2 alkyphenols (AP), and mixtures of 2 types of alkyphenol polyethoxylates (APEOs). Evaluation of estrogenic activity was further characterized by in vitro bioassays using rainbow trout hepatocytes (Oncorhynchus mykiss) and in vivo studies with Japanese medaka (Oryzias latipes). In the in vitro bioassays, hepatocytes exposed to the pesticides alone or in combination with the AP/APEO mixtures at concentrations observed in surface waters failed to show estrogenic activity (induction of vitelloginin mRNA). In the in vivo bioassays, medaka exposed to individual pesticides or to AP/APEO alone did not have elevated VTG at ambient concentrations. However, when the pesticides were combined with AP/APEOs in the 7-day exposure a significant increase in VTG was observed. Exposure to a 5-fold higher concentration of the AP/APEO mixture alone also significantly induced VTG. In contrast to earlier studies with permethrin, biotransformation of bifenthrin to estrogenic metabolites was not observed in medaka liver microsomes and cytochrome P450 was not induced with AP/APEO treatment. These results showed that mixtures of pesticides with significantly different modes of action and AP/APEOs at environmentally relevant concentrations may be associated with estrogenic activity measured in water extracts and feral fish that have been shown to be in population decline in the San Francisco Bay Delta. [ABSTRACT FROM AUTHOR]

Pyrethroids belong to the most commonly used pesticides worldwide. Their massive expansion is a threat to the natural environment including the aquatic ecosystems. Although pyrethroids are rapidly degraded in soil and plants, they are extremelytoxic to fish because of fish high sensitivity to them. Pyretiroids are divided by characteristic into type land type II. Both types cause similar neurological symptoms. They affect sodium channels of nerve filaments and type II pyrethroids even affect chloride and calcium channels. Critical in fish pyrethroid intoxication is slower elimination than in birds and mammals. Pyrethroids are absorbed by fish gills readily. After distribution to bile, liver, kidney and red blood cells, they are metabolized by hydrolysis, hydroxylation and conjugation to glucuronides and sulphates. Disorders of movement and breathing during acute poisoning are followed by death. Chronic effects of pyrethroids induce behaviour changes, blood profile changes, histopathological changes, decreased growth, immune system effects and endocrine effects. Both types of toxicity reduce reproductive potential. Toxicity of pyrethroids depends on many external and internal factors. [ABSTRACT FROM AUTHOR]

Abstract: The Stepwise Behavioral Response Model (SBRM), which is a conceptual model, postulated that an organism displays a time-dependent sequence of compensatory Stepwise Behavioral Response (SBR) during exposure to pollutants above their respective thresholds of resistance. In order to prove the model, in this study, the behavioral responses (BRs) of medaka (Oryzias latipes) in the exposure of Arprocarb (A), Carbofuran (C) and Methomyl (M) were analyzed in an online monitoring system (OMS). The Self-Organizing Map (SOM) was utilized for patterning the obtained behavioral data in 0.1 TU (Toxic Unit), 1 TU, 2 TU, 5 TU, 10 TU and 20 TU treatments with control. Some differences among different Carbamate Pesticides (CPs) were observed in different concentrations and the profiles of behavior strength (BS) on SOM were variable depending upon levels of concentration. The time of the first significant decrease of BS (SD-BS) was in inverse ratio to the CP concentrations. Movement behavior showed by medaka mainly included No effect, Stimulation, Acclimation, Adjustment (Readjustment) and Toxic effect, which proved SBRM as a time-dependence model based on the time series BS data. Meanwhile, it was found that SBRM showed evident stress-dependence. Therefore, it was concluded that medaka SBR was both stress-dependent and time-dependent, which supported and developed SBRM, and data mining by SOM could be efficiently used to illustrate the behavioral processes and to monitor toxic chemicals in the environment. [Copyright &y& Elsevier]

Pesticides applied on land are commonly transported by runoff or spray drift to aquatic ecosystems, where they are potentially toxic to fishes and other nontarget organisms. Pesticides add to and interact with other stressors of ecosystem processes, including surface-water diversions, losses of spawning and rearing habitats, nonnative species, and harmful algal blooms. Assessing the cumulative effects of pesticides on species or ecological functions has been difficult for historical, legal, conceptual, and practical reasons. To explore these challenges, we examine current-use (modern) pesticides and their potential connections to the abundances of fishes in the San Francisco Estuary (California). Declines in delta smelt (Hypomesus transpacificus), Chinook salmon (Oncorhynchus tshawytscha), and other species have triggered mandatory and expensive management actions in the urbanizing estuary and agriculturally productive Central Valley. Our inferences are transferable to other situations in which toxics may drive changes in ecological status and trends. [ABSTRACT FROM AUTHOR]

Contamination with agricultural pesticides such as dichlorodiphenyltrichloroethane (DDT) and its metabolites, dichlorodiphenyldichloroethylene (DDE) and dichlorodiphenyldichloroethane (DDD), is among several proposed stressors contributing to the global declines in amphibian populations and species biodiversity. These chemicals were examined in insects and in the muscle, liver, and eggs of rice frogs ( Rana limnocharis) from the paddy fields of an agricultural site in South China. The ΣDDT (sum of DDT, DDE, and DDD) concentrations ranged from 154 to 915, 195 to 1,400, and 165 to 1,930 ng/g lipid weight in the muscle, liver, and eggs, respectively. All the DDTs (DDT, DDE, and DDD) showed higher affinity for the liver relative to muscle tissue and can be maternally transferred to eggs in female frogs. The average biomagnification factors for DDTs ranged from 1.6 to 1.9 and 1.5 to 2.9 in female and male frogs, respectively, providing clear evidence of their biomagnification from insects to frogs. Compared with the reported DDT levels demonstrated to have toxic effects on frogs, DDTs in the present frogs are unlikely to constitute an immediate health risk. However, the adverse impacts of high DDT residues in eggs on the hatching success and their potential toxicity to the newly metamorphosed larval frogs should be assessed further. Environ. Toxicol. Chem. 2012;31:705-711. © 2011 SETAC [ABSTRACT FROM AUTHOR]

Flounders ( Platichthys flesus) from the waters around Denmark were analysed for their organochlorine (OC) profile to study whether fish from the same genetic population could be separated into characteristic subpopulations, based on their feeding grounds. The chemical analysis of fish liver provided a data set of 16 OC compounds in 94 samples from 2004 to 2006. Except for hexachlorocyclohexane, OC compounds were intercorrelated, indicating similar environmental fate and bioaccumulation. OC profiles are less affected than absolute concentrations by potentially confounding biological factors and thus more suitable for studies of intrapopulation differences in relation to feeding grounds. Principal component analysis grouped the samples according to locations. All but three of the 94 samples could be reclassified. Samples from the same and additional locations collected in 2003 provided validation, with only few misclassifications. This statistical separation likely reflects location-specific pollutant patterns in sediments and biota, even on the relatively small scale of this study. Thus, despite the lack of genetic differences, characteristic subpopulations of flounders could be identified with separate feeding grounds. OC profiles have been used increasingly to distinguish stocks. [ABSTRACT FROM AUTHOR]

Abstract: Pressurized liquid extraction (PLE) combined with in-cell clean-up of co-extracts, so-called selective-PLE (S-PLE), is a fast and accepted method for the analysis of halogenated organic contaminants in fish. However, many of the existing methods were optimized for use with single classes of contaminants. The main objective of this research was to develop an S-PLE method that elutes a minimal amount of fats while simultaneously extracting halogenated pesticides, polychlorinated biphenyls (PCBs), and polybrominated diphenyl ethers (PBDEs) from fat-rich fish. The optimized method uses n-hexane:dichloromethane (75:25, v/v) as the extraction solvent, a 0.0078 fat to fat-retainer ratio (FFR) with Florisil as the fat retainer, three individual 5-min extractions with flush volumes of 150% and a selection of labeled surrogate standards (isotope dilution). This method resulted in a mean recovery of 77% for all target analytes in spiked samples and an average relative standard deviation of 6.3%. The method was validated with a certified reference material; the mean measured analyte concentrations agreed with the reference values except in the case of individual endosulfan isomers. It is likely that interconversion from the beta- to alpha-endosulfan isomer had occurred in the CRM, resulting in low measured concentrations for beta-endosulfan and high measured concentrations for alpha-endosulfan when compared with the reference values. Finally, the method was tested on three fish species with varying fat content. Different contaminant patterns were observed in the various species. [Copyright &y& Elsevier]

Abstract: The QuEChERS method developed for 22 organochlorine pesticides (OCPs) and 7-polychlorinated biphenyls (PCBs) in fish tissue involves a simple and efficient freezing technique for removal of lipids. The equipment developed consists of disposable syringes and a freezing block constructed from simple materials found in most laboratories. The freezing block keeps the temperature in the extract at −20.5°C up to 10min after being exposed to room temperature. After the freezing step 69% of the lipids in tilapia and 61% in salmon are removed. Further reduction of co-extractives up to 96% in tilapia and 87% in salmon can be made by treatment with CaCl2 and primary secondary amino sorbent (PSA) which removes the fatty acids. Spiking experiments in tilapia at 5 and 50ng/g and extracted with acetonitrile show recovery range from 70 to 115% for all compounds. In salmon the recoveries are in the range 43–118% for the OCPs and 26–65% for the PCBs. Analysis of a standard reference material shows acceptable results for most of the pesticides but low results for the PCBs. The estimated LOQs were in the range 1–5ng/g for tilapia and 2–10ng/g for salmon. The method has been applied to analyse fish samples from Lake Koka in Ethiopia. It was investigated if addition of a less polar water miscible solvent than acetonitrile could increase the recovery of OCPs and PCBs. The results show that a mixture of 75% acetonitrile and 25% tetrahydrofurane (ACN/THF 75/25) clearly enhances the recoveries for most OCPs (47–101%) and PCBs (42–79%) from salmon. The recovery of aldrin increases significantly from 55% to over 80%. The method using ACN/THF 75/25 is applicable to the extraction of OCPs and PCBs from fish tissue having a lipid content of up to about 11% (salmon) with recoveries ≥70% for most of the OCPs and ≥42% for the PCBs. [Copyright &y& Elsevier]

Abstract: The impact of acute and sublethal toxicity of a synthetic organochlorine pesticide lindane on some haematological and biochemical parameters of a freshwater fish Cyprinus carpio was estimated. The median lethal concentration of lindane for 24h was 0.38ppm. During acute treatment (24h), hemoglobin (Hb), hematocrit (Hct) and erythrocyte (RBC) values were decreased, whereas leucocyte (WBC) count increased in the pesticide treated fish. The hematological indices like mean cellular volume (MCV), mean cellular hemoglobin (MCH) and mean cellular hemoglobin concentration (MCHC) were decreased when compared to control group. Biochemical profiles like plasma glucose and protein levels were increased in lindane exposed fish showing a percent increase of 50.36 and 3.98 at the end of 24h treatment. However, glycogen content in liver and muscle were decreased showing a percent decrease of 21.70 and 1.74. In sublethal treatment (1/10th of LC50 24h value, 0.038ppm), RBC count was decreased whereas WBC count increased in the pesticide treated fish throughout the study period (25days). Hb and Hct values were decreased up to 10th day and after that recovered showing a significant increase in the rest of the study period. Similarly, a biphasic response was observed in the value of MCV, MCH and MCHC. Plasma glucose level was significantly increased while plasma protein level decreased throughout the study period. Further, glycogen level in muscle and liver were showed a mixed trend. In the present study, the pesticide lindane caused alterations on haematological and biochemical parameters of C. carpio and these alterations can be used as non specific biomarkers in pesticide contaminated aquatic ecosystem. [Copyright &y& Elsevier]

Abstract: The present study was conducted in order to investigate pro-oxidant activity of dimethoate in liver and brain tissues following sublethal pesticide exposure for 5, 15 and 30d by using SOD, GPx, CAT enzyme activities and lipid peroxidation as biomarkers as well as DNA damaging potential via detecting% Tail DNA, Tail moment and Olive tail moment as endpoints in erythrocytes of Oncorhynchus mykiss in an in vitro experiment. Antioxidant enzyme activities were found to elicit two staged response which was an initial induction followed by a sharp inhibition in liver tissue while a sustained increase in GPx activity and slight stimulation in SOD activity were detected in brain tissue. Lipid peroxidation showed an ascending pattern throughout the exposure period in both tissues and a decreasing trend was determined in tissue protein levels which was proved to be positively correlated with duration. Similar findings were obtained from outcomes preferred to quantify DNA damage and TM was decided to reflect the extent of damage more sensitively because of determined positive correlation with concentrations applied. Considering these results, it can be concluded that oxidative stress condition evoked by dimethoate could not be responded effectively and genotoxic nature of pesticide was proven by determined clastogenic effect possibly via being an alkylation agent or stimulating the production of reactive species. [Copyright &y& Elsevier]

Abstract: In this study, fish Rhamdia quelen, were exposed to different concentrations of herbicide clomazone: 0.0 (control), 0.45 and 0.91mgL−1. After exposure for 8days to herbicide, fish were transferred to clean water for a recovery period (8days). Oxidative stress indicators such as thiobarbituric acid reactive substances (TBARS) levels and protein carbonyl content, as well as antioxidant defenses, such as catalase (CAT), superoxide dismutase (SOD), glutathione S-transferase (GST), ascorbic acid and non-protein thiols levels were studied, using the liver, brain and muscle tissues. Herbicide exposure increased TBARS in muscle and in liver at higher concentration. In liver protein carbonylation increased and catalase activity did not change in fish exposed to herbicide. SOD enhanced in liver at concentration of 0.91mgL−1. GST, ascorbic acid and non-protein thiols levels increase at both concentrations. At the end of the recovery period the most of the parameters recovered whereas GST and ascorbic acid remain elevated. The present study demonstrates the occurrence of disorders in antioxidant parameters and importance in the assessment of the potential risk of herbicides as clomazone on fish species. [Copyright &y& Elsevier]

The ability of targeted and nontargeted metabolomics to discover chronic ecotoxicological effects is largely unexplored, Fenitrothion, an organopho-sphate pesticide, is categorized as a "red Ust" pollutant, being particularly hazardous to aquatic life. It acts primarily as a Cholinesterase inhibitor, but evidence suggests it can also act as an androgen receptor antagonist Whole-organism fenitrothion-induced toxicity is well-established, but information regarding target and off-target molecular toxicities is limited. Here we study the molecular responses of male roach (Rutilus rutilus) exposed to fenitrothion, including environmentally realistic concentrations, for 28 days. Acetylcholine was assessed in brain; steroid metabolism was measured in testes and plasma; and NMR and mass spectrometry-based metabolomics were conducted on testes and liver to discover off-target toxicity. O-demethylation was confirmed as a major route of pesticide degradation. Fenitrothion significantly depleted acetylcholine, confirming its primary mode of action, and 11-ketotestosterone in plasma and cortisone in testes, showing disruption of steroid metabolism. Metabolomics revealed significant perturbations to the hepatic phosphagen system and previously undocumented effects on phenylalanine metabolism in liver and testes. On the basis of several unexpected molecular responses that were opposite to the anticipated acute toxicity, we propose that chronic pesticide exposure induces an adapting phenotype in roach, which may have considerable implications for interpreting molecular biomarker responses in field-sampled fish. [ABSTRACT FROM AUTHOR]

As a major ecosystem type, wetland provides invaluable ecological services. Environmental pollution, especially pesticides pollution should be paid more attention to keep wetlands healthy. Based on the risk quotient method, coupled with a probabilistic risk assessment model, this paper proposed a methodology suitable for ecological risk assessment of pesticide residues for wetland ecosystems. As an important industrializing and ecologically vulnerable area in China, the Taihu Lake wetland was chosen for the case study. The risks of eight pesticides in Taihu Lake wetland were assessed, as single substances and in mixtures. The assessment indicates that risks of the representative species are not significant. In general, the herbicide is found to be more toxic for algae, whereas insecticides pose more risks to zooplankton, insect and fish. For each pesticide in the wetland, the ecological risk it poses is acceptable. But the combined ecological risk posed by mixture can harm more than 10% of species of the wetland ecosystem, mainly dominated by dichlorvos, dimethoate and malathion contributions. These results imply that pesticide residues have been posing pressures on the ecosystem of the Taihu Lake wetland. It is recommended that proper countermeasures should be implemented to reduce the risks. [Copyright &y& Elsevier]

Abstract: Pesticides are nearly ubiquitous in surface waters of the United States, where they often are found as mixtures. The molecular mechanisms underlying the toxic effects of sub-lethal exposure to pesticides as both individual and mixtures are unclear. The current work aims to identify and compare differentially expressed proteins in brains of male fathead minnows (Pimephales promelas) exposed for 72h to permethrin (7.5μg/L), terbufos (57.5μg/L) and a binary mixture of both. Twenty-four proteins were found to be differentially expressed among all three treatments relative to the control using an ANOVA followed by a Dunnett''s post hoc test (p ≤0.05). One protein was found to be differentially expressed among all treatment groups and one protein was in common between the terbufos and the mixture group. Fifteen spots were successfully sequenced using LC–MS/MS sequencing. Proteins associated with the ubiquitin–proteasome system, glycolysis, the cytoskeleton and hypoxia were enriched. As a second objective, we attempted to establish protein expression signatures (PES) for individual permethrin and terbufos exposures. We were unable to generate a useable PES for terbufos; however, the permethrin PES was able to distinguish between control and permethrin-exposed individuals in an independent experiment with an accuracy of 87.5%. This PES also accurately classified permethrin exposed individuals when the exposure occurred as part of a mixture. The identification of proteins differentially expressed as a result of pesticide exposure represent a step forward in the understanding of mechanisms of toxicity of permethrin and terbufos. They also allow a comparison of molecular responses of the binary mixture to single exposures. The permethrin PES is the first step in establishing a method to determine exposures in real-world scenarios. [Copyright &y& Elsevier]

Abstract: The resistance of fish to microorganisms challenge depends mainly on the efficacy of the immune response. Most studies on the natural immune response of fish have focused on the effect of diets and immunostimulants. Few studies correlated the presence of commonly used agrichemical and susceptibility to infection by aquatic microorganism. Thus, this study aimed to investigate the effect of glyphosate and atrazine-based herbicides on immune cell phagocytosis and susceptibility of silver catfish to Aeromonas hydrophila infection. Following exposure to sublethal concentrations of glyphosate or atrazine (10% of the LC50–96 h), a significant decrease in the number of intracelomatic cells and phagocytic index could be observed. In addition, silver catfish fingerlings exposed to glyphosate or atrazine were more susceptible to intracelomatic challenge with pathogenic A. hydrophila. Thus, the presence of these herbicides on the water alters the natural immune response to bacterial and possibly to other aquatic microorganism. [ABSTRACT FROM AUTHOR]

Abstract: Medetomidine is a new antifouling agent, and its effects in non-target aquatic organisms have been investigated. Earlier short-term studies in fish have shown a skin lightening response to medetomidine, but effects after chronic exposure have not been studied. In fish, the dark pigment melanin is contained within specialized cells, melanophores. Medetomidine binds to the melanophore α2-adrenoceptor, which stimulates pigment aggregation resulting in the light appearance. In the present study, rainbow trout (Oncorhynchus mykiss) was long-term exposed to 0.5 and 5.0nM of medetomidine via water for 54d. The fish were then photographed for paleness quantification and the images were analyzed using ImageJ analysis software. Additionally, scales were removed and used for in vitro function studies of the melanophores, monitoring the response to melanophore stimulating hormone (MSH) and subsequent medetomidine addition. The number of melanophores was also investigated. As a result of the medetomidine exposure, fish from the 5nM treatment were significantly paler than control fish and the melanophores from these fishes were also more aggregated. Melanophores from all the treatments were functional, responding to MSH by dispersion and to subsequent medetomidine by aggregation. However, the results indicate a difference in sensitivity among treatments. The number of melanophores in the scales did not change significantly after long term exposure to medetomidine. These results suggest that the observed paleness may be reversible, even after chronic exposure. [ABSTRACT FROM AUTHOR]

Background: Persistent organic pollutants (POPs), including polychlorinated biphenyls (PCBs) and chlorinated pesticides, have been shown to have many adverse human health effects. These contaminants therefore may pose a risk to Alaska Natives that follow a traditional diet high in marine mammals and fish, in which POPs bioaccumulate. Methods and Findings: This study examined the levels of PCBs and three pesticides [p, p9-DDE, mirex, and hexachlorobenzene (HCB)] in muscle tissue from nine fish species from several locations around the Aleutian Islands of Alaska. The highest median PCB level was found in rock sole (Lepidopsetta bilineata, 285 ppb, wet weight), while the lowest level was found in rock greenling (Hexagrammos lagocephalus, 104 ppb, wet weight). Lipid adjusted PCB values were also calculated and significant interspecies differences were found. Again, rock sole had the highest level (68,536 ppb, lipid weight). Concerning the PCB congener patterns, the more highly chlorinated congeners were most common as would be expected due to their greater persistence. Among the pesticides, p, p9-DDE generally dominated, and the highest level was found in sockeye salmon (Oncorhynchus nerka, 6.9 ppb, wet weight). The methodology developed by U.S. Environmental Protection Agency (USEPA) was used to calculate risk-based consumption limits for the analyzed fish species. For cancer health endpoints for PCBs, all species would trigger strict advisories of between two and six meals per year, depending upon species. For noncancer effects by PCBs, advisories of between seven and twenty-two meals per year were triggered. None of the pesticides triggered consumption limits. Conclusion: The fish analyzed, mainly from Adak, contain significant concentrations of POPs, in particular PCBs, which raises the question whether these fish are safe to eat, particularly for sensitive populations. However when assessing any risk of the traditional diet, one must also consider the many health and cultural benefits from eating fish. [ABSTRACT FROM AUTHOR]

Abstract: Dithiocarbamates (DTCs) are a class of compounds that are extensively used in agriculture as pesticides. As such, humans and wildlife are undoubtedly exposed to these chemicals. Although DTCs are thought to be relatively safe due to their short half lives, it is well established that they are teratogenic to vertebrates, especially to fish. In zebrafish, these teratogenic effects are characterized by distorted notochord development and shortened anterior to posterior axis. DTCs are known copper (Cu) chelators but this does not fully explain the observed teratogenic effects. We show here that DTCs cause malformations in zebrafish that highly resemble teratogenic effects observed by direct inhibition of a group of cuproenzymes termed lysyl oxidases (LOX). Additionally, we demonstrate that partial knockdown of three LOX genes, lox, loxl1 and loxl5b, sensitizes the developing embryo to DTC exposure. Finally, we show that DTCs directly inhibit zebrafish LOX activity in an ex vivo amine oxidase assay. Taken together, these results provide the first evidence that DTC induced teratogenic effects are, at least in part, caused by direct inhibition of LOX activity. [Copyright &y& Elsevier]

Diazinon is an organophosphate pesticide widely used in agricultural areas (especially paddy fields) in Iran. Similar to other pesticides, diazinon may enter aquatic systems due to run-off and affect various organisms living in rivers and estuaries. Persian sturgeon Acipenser persicus is one of the most economically important species in the Caspian Sea, which enters Iranian rivers, such as the Sefidroud River, for breeding. Fish eggs hatch in the river and fingerlings migrate to the sea after a period of time. The International Sturgeon Research Institute in Rasht, Iran, produces and releases millions of fingerling sturgeons into the coastal area of the Caspian Sea annually and the fingerlings may thus be affected by this pesticide. This study was carried out to determine sublethal effects of diazinon on some hematological indices of Persian sturgeon under lab conditions. Fish were exposed to concentrations of 0, 0.01, 1.095 (0.25 LC50), 2.19 (0.5 LC50) or 3.285 ppm (0.75 LC50) diazinon and responses were studied after 12, 24 and 96 h. After 12 h exposure, the fingerlings exposed to 2.19 and 3.285 ppm revealed a series of abnormal responses such as muscle paralysis, change in gills and abdominal color, erratic swimming, rapid operculum movement, and loss of body balance. The exposed sturgeons also exhibited a significantly lower number of erythrocyte (RBC) and leukocyte count (WBC) after 24 and 96 h exposure. Similarly, after 96 h, there was a significant decrease in hematocrit (Htc). Results also revealed a decrease in lymphocyte numbers and an increase of meta neutrophils, band neutrophils and total neutrophils after 24 and 96 h diazinon. Data suggest that diazinon affects physiological and hematological functions of A. persicus, which may finally affect survival of the fish. Diazinon concentration of 0.01 ppm has been recorded in water of the Sefidroud River, where about five million Persian sturgeon fries are released annually by the Iranian department of fishery hatcheries. Since this level of pesticide was found to be toxic for fish fries, it is critical to avoid any toxic impact by regular monitoring of diazinon levels in the river water. [ABSTRACT FROM AUTHOR]