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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]

The article presents a study which investigates the toxicity level of pesticides to zebrafish (Brachydanio rerio). It states that the study used acute toxicity bioassays by exposing the fish to various concentrations of the test insecticides. The study concluded that there was very high toxicity levels of all pyrethroid insecticides and low toxicity level of organophosphate dichlorvos. It adds that the water quality requirement of the fish must be studied further.

This study assessed the effect of fenvalerate pesticide on the kidney condition Renatosomatic Index (RSI) of a freshwater fish Clarias batrachus. Fenvalerate is a pyrethroid pesticide. The RSI showed decreasing trend when the fishes were exposed to different sub lethal concentrations i. e., 0.02 ppm, 0.04 ppm and 0.08 ppm of fenvalerate for 96 hours. This condition of kidney of the fish can result from incomplete elimination of the fenvalerate from the kidney, thereby affecting the normal metabolism of the fish. Thus, the pyrethroid pesticide such as fenvalerate should be used with caution in agriculture field applications, as it is likely to introduce acute levels of the toxicant into the environment. [ABSTRACT FROM AUTHOR]

Abstract: Endosulfan, a broad-spectrum non-systemic organochlorine (OC) pesticide is extensively used to control a wide variety of pests in agriculture, horticulture and public health programmes. Biochemical changes occurring in the metabolically active tissues of gills (GL), hepatopancreas (HP) and muscle (MU) of the penaeid shrimp, Metapenaeus monoceros (Fabricius) on exposure to two sublethal doses (40 and 60ngL−1) of endosulfan were studied for 23 days of exposure (DoE). Sublethal doses of endosulfan significantly (P <0.05) altered the levels of the total protein (TP), the total carbohydrates (TC), the glycogen (GLY), the total free sugars (TFS) and the total lipids (TL) in test shrimps. Concentrations of biochemical components significantly varied with the DoE but were dose-independent (P <0.05). Percent decrease in all biochemical components increased with the progress of the DoE irrespective of the exposure concentrations. The order of percent decrease in the concentrations of the TP, TC, GLY, TL and TFS in different tissues at the end of 23 DoE was found to be MU>GL>HP, HP>GL>MU, MU>HP>GL, HP>MU>GL and MU>GL>HP, respectively. The results of the study revealed that sublethal doses of endosulfan significantly alters the proximate composition of major tissues, particularly the TP levels in the MU tissues thereby reducing the nutritive value of this economically important penaeid shrimp. Since M. monoceros exhibits significant biochemical changes on exposure to endosulfan, this species could possibly be used as biosensor of coastal marine and estuarine pollution by OCs. [Copyright &y& Elsevier]

The article presents a study on the impact of tributyltin (TBT) and 17 β-Estradiol (E2) in male Chinese loach or Misgurnus anguillicaudatus, a cold-water fish. The study used the loaches in a semistatic waterborne exposure system to examine the effects of TBT on the production of vitellogenin (Vtg) induced by E2. It also investigates the accumulation of TBT and distribution in tissues. Findings of the study indicate that it did not induce the synthesis of Vtg in Chinese loach and could significantly inhibit the production caused by E2 after exposure to binary mixtures for 14 days. It also shows that it accumulates in the intestine, liver and kidney of the fish.

The article presents a study on the impact of malathion, a kind of pesticide commonly used in households and agriculture to terminate harmful organisms. It states that the pesticide has toxic substances which could be dangerous to living things particularly to fishes. It investigates its effects on lipid peroxidation and antioxidant systems in the kidney, intestine and gills of Carassius auratus gibelio, a wild form of goldfish. Findings of the study indicate that the lipid peroxidation and antioxidative defense mechanisms show different responses in examined tissues. It notes that they increased after one day of malathion administration and changes in reduced glutathione levels have been recorded after six days of pesticide exposure.

Abstract: We investigated the in vitro and in vivo effects of some pesticides on rainbow trout erythrocyte glucose-6-phosphate dehydrogenase enzyme. The enzyme was purified 1691-fold with a specific activity of 16.235U/mg protein and a yield of 63%. Cypermethrin, and propoxur inhibited glucose-6-phosphate dehydrogenase enzyme in vitro and deltamethrin inhibited both in vivo and in vitro. The obtained IC50 values for deltamethrin, cypermethrin, and propoxur were 0.63, 1.02, and 12mM, respectively. The activity of the control was determined as 5.17±0.62U/g Hb in in vivo studies. The enzyme activities of the groups treated with 0.25g/L deltamethrin were measured at 6, 12, 24, 48, and 72h, and found to be 4.32±0.47, 3.57±0.39, 3.47±0.45, 2.86±0.37, and 2.31±0.32U/g Hb. In vivo experiments showed that deltamethrin significantly inhibited the G6PD enzyme activity after the 48thh (p <0.05). [Copyright &y& Elsevier]

Abstract: Pesticides, such as herbicides can affect the metabolic and toxicological parameters on fish. For this reason, an experiment was carried out with the objective of to evaluate the effects of commercial formulations of clomazone and propanil herbicides on acetylcholinesterase (AChE), thiobarbituric acid-reactive substances (TBARS), catalase (CAT) and metabolic parameters in teleost fish (Leporinus obtusidens). Fish were exposed during 90 days to field measured concentration of the herbicides clomazone and propanil (376 and 1644μg/L, respectively) on rice paddy water. Specific AChE activity in the brain and muscle decreased and TBARS levels decreased in brain, muscle and liver tissues. Liver catalase decreased after exposure to both herbicides. Metabolic parameters in the liver and white muscle showed different changes after exposure to both herbicides. In summary, the results showed that clomazone and propanil affects toxicological and metabolic parameters of piavas. These results suggest that environmentally relevant herbicides concentrations are toxic to Leporinus obtusidens. [Copyright &y& Elsevier]

Abstract: This study investigated the possible effects of a commonly used foliar herbicide 2,4-dichlorophenoxyacetic acid (2,4-D) formulation on medulla spinalis of lebistes. Fish were exposed to 2,4-D (15, 30, 45mgL−1), behavioral changes were monitored. Fish were fixed, histopathological examination was carried out on sections taken from the upper parts of the fish body. Histopathology showed increase in neuronal loss, swelling indicating formation of intracellular edema, vacuolization noticed as the formation of vacuoles within or adjacent to cells, deformation in the Nissl granules, pyknosis and gliosis in medulla spinalis. Behavioral changes were decreased general activity, grouping, shortness in breath, sudden rotations and jumping, loss of equilibrium and colour. In conclusion, this commercial formulation of 2,4-D is considerably neurotoxic to lebistes. Fish constitute the last link in the chain of the feeding cycle in aquatic eco-system, number of studies investigating acute and chronic neurotoxicity of various herbicides in fish should be increased. [Copyright &y& Elsevier]

Abstract: We investigated how pesticide contamination of water affects the metabolism of the silver catfish, Rhamdia quelen, by studying fish maintained at two sites with low and high anthropic activity (Lino Creek, southern Brazil). Several pesticides were found at both stream sites. After 30 days plasma glucose levels were higher in fish exposed to water in the low anthropic activity site than those exposed to water in the high anthropic activity site. Plasma K+ levels, however, were lower after exposure to low anthropic water than after exposure to high anthropic water. Moreover, values of hepatic glycogen, muscle lactate and protein were higher, but glycogen and protein of the kidney were lower in fish exposed to water at the high anthropic activity site. Our results show that these fish can be used as pesticide toxicity indicators in streams near agricultural fields. [Copyright &y& Elsevier]

This study measures a whole series of biological endpoints, and histopathological and behavioral changes of carp (Cyprinus carpio L.) fingerlings in order to investigate the adverse effects of a sublethal concentration of 10¿g/L cyfluthrin for 48h and one week using the semi-static test system. The most significantly altered findings of this study was that total antioxidant status levels decreased in 48h, chloride levels decreased in one week, and sodium and phosphorous levels increased in the 48h-exposed group. Plasma cortisol increased in both the 48h-exposed and the one-week-exposed groups. The unique tissue was the brain that had an increased level of malondialdehyde after one week of exposure. Such biomarkers may be used in assessing adverse/toxic effects of pesticides as environmental stressors. Potential oxidative-stress-inducing effect of synthetic pyrethroid cyfluthrin, as lipid peroxidation, in addition to its sodium channel blocking, is reported for the first time as an additional mechanism of action. [Copyright &y& Elsevier]

Empirical regression models were developed for estimating concentrations of dieldrin, total chlordane, and total DDT in whole fish from U.S. streams. Models were based on pesticide concentrations measured in whole fish at 648 stream sites nationwide (1992-2001) as part of the U.S. Geological Survey's National Water Quality Assessment Program. Explanatory variables included fish lipid content, estimates (or surrogates) representing historical agricultural and urban sources, watershed characteristics, and geographic location. Models were developed using Tobit regression methods appropriate for data with censoring. Typically, the models explain approximately 50 to 70% of the variability in pesticide concentrations measured in whole fish. The models were used to predict pesticide concentrations in whole fish for streams nationwide using the U.S. Environmental Protection Agency's River Reach File 1 and to estimate the probability that whole-fish concentrations exceed benchmarks for protection of fish-eating wildlife. Predicted concentrations were highest for dieldrin in the Corn Belt, Texas, and scattered urban areas; for total chlordane in the Corn Belt, Texas, the Southeast, and urbanized Northeast; and for total DDT in the Southeast, Texas, California, and urban areas nationwide. The probability of exceeding wildlife benchmarks for dieldrin and chlordane was predicted to be low for most U.S. streams. The probability of exceeding wildlife benchmarks for total DDT is higher but varies depending on the fish taxon and on the benchmark used. Because the models in the present study are based on fish data collected during the 1990s and organochlorine pesticide residues in the environment continue to decline decades after their uses were discontinued, these models may overestimate present-day pesticide concentrations in fish. [ABSTRACT FROM AUTHOR]

A survey of 29 pesticides were performed for water, fish and shellfish from two littoral areas of Lake Biwa and Yanamune River in 2007. Three insecticides, 5 fungicides and 13 herbicides were detected in the water from the sampling locations, but the insecticides and fungicides were not and the only 9 herbicides were detected in the fish and shellfish from the locations. Bioconcentration factors (BCF) of the 9 herbicides in the fish and shellfish were calculated by the field data obtained from the survey. The average field BCF values of the herbicides in the fish were 8 and 25 for molinate, 5–23 for bromobutide, 4 and 10 for simetryn, 100–214 for esprocarb, 15–41 for pretilachlor, 148 for anilofos, 14 and 79 for mefenacet and 78 for cafenstrole. Those in the shellfish were 6 and 13 for bromobutide, 4 and 8 for simetryn, 67 and 135 for esprocarb, 2 for pretilachlor, 117 for pyributicarb and 57 and 139 for mefenacet. The field BCF data in the fish were evaluated by laboratory BCF data from literatures for molinate, bromobutide, pretilachlor, simetryn and mefenacet. [ABSTRACT FROM AUTHOR]

We conducted acute and chronic toxicity studies of the effects of picloram acid on the threatened bull trout ( Salvelinus confluentus) and the standard coldwater surrogate rainbow trout ( Oncorhynchus mykiss). Juvenile fish were chronically exposed for 30 days in a proportional flow-through diluter to measured concentrations of 0, 0.30, 0.60, 1.18, 2.37, and 4.75 mg/L picloram. No mortality of either species was observed at the highest concentration. Bull trout were twofold more sensitive to picloram (30-day maximum acceptable toxic concentration of 0.80 mg/L) compared to rainbow trout (30-day maximum acceptable toxic concentration of 1.67 mg/L) based on the endpoint of growth. Picloram was acutely toxic to rainbow trout at 36 mg/L (96-h ALC50). The acute:chronic ratio for rainbow trout exposed to picloram was 22. The chronic toxicity of picloram was compared to modeled and measured environmental exposure concentrations (EECs) using a four-tiered system. The Tier 1, worst-case exposure estimate, based on a direct application of the current maximum use rate (1.1 kg/ha picloram) to a standardized aquatic ecosystem (water body of 1-ha area and 1-m depth), resulted in an EEC of 0.73 mg/L picloram and chronic risk quotients of 0.91 and 0.44 for bull trout and rainbow trout, respectively. Higher-tiered exposure estimates reduced chronic risk quotients 10-fold. Results of this study indicate that picloram, if properly applied according to the manufacturer’s label, poses little risk to the threatened bull trout or rainbow trout in northwestern rangeland environments on either an acute or a chronic basis. [ABSTRACT FROM AUTHOR]

Abstract: A simple and fast method for the simultaneous analysis of thiobencarb, deltamethrin and 19 organochlorine pesticide residues in fish by gas chromatography–mass spectrometry was investigated in this study. Samples are extracted with acetonitrile. Most of lipids in the extract are eliminated by low-temperature cleanup, prior to solid-phase extraction cleanup. The lipids extracted from the fish samples were easily removed without any significant losses of the pesticides. Aminopropyl (NH2) cartridge was effective to eliminate the remaining interference. Spiked experiments were carried out to determine the recovery, precision and limits of detection (LODs) of the method. The method detection limits ranged from 0.5μgkg−1 to 20μgkg−1, whilst recoveries of the pesticides were in the range of 81.3–113.7% with relative standard deviations ⩽13.5% at a spiked concentration of 0.05mgkg−1, 0.02mgkg−1 and 0.1mgkg−1. The newly developed method is demonstrated to give efficient recoveries and LODs for detecting pesticide multiresidues in fish. [Copyright &y& Elsevier]

This article discusses research wherein adult fish were exposed to methyl parathion (MeP) and bioaccumulation trends were observed. MeP is an insecticide commonly used in Mexico, which has been discovered in water bodies near agricultural lands and within the tissue of the viviparous fish amarillo (Girardinichthys multiradiatus). Fish that accumulated the compound exhibited significant reductions in weight and growth rate. Results of this study indicate that low MeP concentrations during gestation affect fish later on in life.

Abstract: The use of malachite green (MG) in fish farming is prohibited in China due to its potentially toxicological and carcinogenic nature, but it is still illegally used in some places. Uptake, accumulation and depuration of MG in various tissues were studied under laboratory conditions in three common freshwater fish, Parabramis pekinensis (plant-eating fish), Carassius auratus (omnivorous fish) and Ophiocephalus argus (carnivorous fish). The concentrations of MG and its primary metabolite, the reduced and colorless leucomalachite green (LMG), were analyzed by liquid chromatography–mass spectrometry (LC–MS2). Absorption of MG occurred during the waterborne exposure and the MG concentrations in gills of the three fish species all showed a maximum at 0 h after an acute water exposure (6 mg l− 1 MG for 20 min). Afterwards, both MG and LMG declined very rapidly in the blood of the fish. Levels of MG and LMG were still above 0.002 μg g− 1 in fresh weight muscle at 240 h and may persist for as long as 10 days. Most MG was converted rapidly to LMG in the fish and depuration of LMG was very slow in fat tissue, skin and gonads of the fish. Distribution of LMG was strongly dependent on the fat content in the tissues of the fish, but not related to their different feeding habits. Therefore, it appears that fat tissue, skin and gonads of the fish contaminated by MG and LMG pose the greatest risk for human consumption. [Copyright &y& Elsevier]

BACKGROUND: Mixtures of organophosphate and carbamate pesticides are commonly detected in freshwater habitats that support threatened and endangered species of Pacific salmon (Oncorhynchus sp.). These pesticides inhibit the activity of acetylcholinesterase (AChE) and thus have potential to interfere with behaviors that may be essential for salmon survival. Although the effects of individual anticholinesterase insecticides on aquatic species have been studied for decades, the neurotoxicity of mixtures is still poorly understood. OBJECTIVES: We assessed whether chemicals in a mixture act in isolation (resulting in additive AChE inhibition) or whether components interact to produce either antagonistic or synergistic toxicity. METHODS: We measured brain AChE inhibition in juvenile coho salmon (Oncorhynchus kisutch) exposed to sublethal concentrations of the organophosphates diazinon, malathion, and chlorpyrifos, as well as the carbamates carbaryl and carbofuran. Concentrations of individual chemicals were normalized to their respective median effective concentrations (EC50) and collectively fit to a nonlinear regression. We used this curve to determine whether toxicologic responses to binary mixtures were additive, antagonistic, or synergistic. RESULTS: We observed addition and synergism, with a greater degree of synergism at higher exposure concentrations. Several combinations of organophosphates were lethal at concentrations that were sublethal in single-chemical trials. CONCLUSION: Single-chemical risk assessments are likely to underestimate the impacts of these insecticides on salmon in river systems where mixtures occur. Moreover, mixtures of pesticides that have been commonly reported in salmon habitats may pose a more important challenge for species recovery than previously anticipated. [ABSTRACT FROM AUTHOR]

Abstract: The herbicide atrazine (ATZ) is one of the most widely used pesticides in the world and is now under scrutiny for its alleged capacity to disrupt the endocrine system. Exhibiting negligible interaction with the estrogen receptor (ER), ATZ''s mode of action remains to be elucidated. ATZ may act as an inducer of the enzyme aromatase, which converts androgens to estrogens, although other mechanisms should also be taken into consideration such as impairment of hepatic metabolism. Therefore we administered juvenile rainbow trout (Oncorhynchus mykiss) a dose of either 2 or 200 μg ATZ/kg, or of carrier control phosphate buffered saline (PBS) and we measured plasma concentrations of testosterone (T), 17beta-estradiol (E2) and vitellogenin (Vtg) 6 days after exposure. Simultaneously we analyzed hepatic gene expression of cytochrome P450 (CYP) 1A and pi-class glutathione S-transferase (GST-P), and catalase (CAT) activity. Although sex steroid levels showed no significant alterations, we found a dose-dependent increase in Vtg and a concomitant decrease in CYP1A. There was no effect of ATZ on GST-P mRNA levels but GST-P was positively correlated with CYP1A. Also, CYP1A was negatively correlated with liver CAT and E2, and varied with T concentrations in a hormetic manner. The results showed that ATZ can alter hepatic metabolism, induce estrogenic effects and oxidative stress in vivo, and that these effects are linked. [Copyright &y& Elsevier]

Abstract: Investigation of lethal dose of γ-HCH (gamma isomer of hexachlorocyclohexane), DDT (dichlorodiphenyltrichloroethane) and chlorpyrifos on spermatozoa motility after 40 days exposure in catfish, Heteropneustes fossilis was done under laboratory conditions. The sperm motility was done in the fishes captured from unpolluted ponds of Gujartal considering as reference site and polluted rivers Gomti and Ganga of north India at pre-spermiating stage. Results indicate that 1ppm of γ-HCH, DDT and chlorpyrifos was lethal dose on sperm motility. The motility of spermatozoa decreased in insecticide exposed fish as well as in the fishes of polluted rivers when compared with their respective controls. The sperm motility was highest at 1:2000 (testicular milt: extender) dilution and duration of sperm motility was 90s after post-activation. The duration of motility also declined in the fishes captured from polluted rivers when compared with the same species captured from the reference site. It is concluded that the insecticides decrease the sperm motility and its duration in exposed fish as well as in the captured fishes from polluted rivers causing the decline in fish population of riverine systems due to influence of xenobiotics on the endocrine system. [Copyright &y& Elsevier]

Monocrotophos, commonly known as azodrin, is one of the organophosphate pesticides extensively used in agricultural practices throughout the world. However, little information is available on its long-term genotoxic effects in different tissues of fish using genotoxicity biomarkers. The objective of the present study was to detect DNA damage, induced by monocrotophos in freshwater teleost fish Channa punctatus using the comet assay. The LC50-96 h value of technical-grade monocrotophos was estimated for the fish species in a semi-static system. On the basis of the LC50 value, the sublethal and nonlethal concentrations were determined. The DNA damage was measured in the gill, kidney and lymphocytes as the percentage of DNA in comet tails of fish exposed to different sublethal and nonlethal concentrations of monocrotophos. In general, significant effects (P <0.01) from both concentration and time of exposure were observed in exposed fish. It was found that the tissues at all concentrations exhibited the highest DNA damage on day 4, after which there was a decline in percentage tail DNA. The comparison of DNA damage among tissues at different concentrations indicated that the gill cells were more sensitive to the pesticide than the kidney cells and lymphocytes. This study also explored the utility of the comet assay for in vivo laboratory studies using fish for screening the genotoxic potential of various agents. [Copyright &y& Elsevier]

Abstract: For assessing the impact of chlorinated compounds, such as organochlorine pesticides, polychlorinated biphenyls, chlorotriazines (atrazine, simazine), and chlorinated phenylureas (diuron), on the Ponta Grossa lake South of Brazil, ten freshwater trahira fish (Hoplias malabaricus) were collected in October 2005. The contamination status was evaluated by the energy budget and various histopathological markers. The results showed detectable amounts of persistent organic pollutants (POPs) in the liver and muscle; the bioaccumulation was higher in the liver than in the muscle. The presence of some banned pesticides, such as hexachlorobenzene and dichlorodiphenyltrichloroethane, in the liver suggests an acute exposure to these compounds. Some physiological disturbances and morphological damages found in the liver of H. malabaricus were associated with chlorinated-compound bioaccumulation. The most important alterations in the liver were lesions such as fibrosis, large necrosis area, leukocyte infiltration, and the absence of melanomacrophages (MM). Individuals containing higher concentrations of pesticides, such as aldrin, alachlor, and dichloroaniline (a metabolite of diuron), showed the nonoccurrence of MM in the liver. These data suggest an immunosuppression in the individuals from Ponta Grossa Lake after exposure to POPs. According to the present data, the POPs found in the studied site are bioavailable, induce severe damages in target organs such as the liver, and can disturb the immune system of the trahira. This is the first study of POPs in the Paraná state, and one among the few studies in the south of Brazil. The present data suggest and motivate further chemical and biomonitoring studies in freshwater ecosystems in the south of Brazil. [Copyright &y& Elsevier]

We evaluated the alterations of organochlorinated compounds such as polychlorobiphenyls (PCB), dichloro-diphenyl-dichloroethylene (DDE) and dichloro-diphenyl-trichloroethane (DDT) on the thyroid in wild and cultured sea bass (Dicentrarchus labrax) at environmental concentrations. These compounds influence the endocrine system of many fish species and are qualified as endocrine disruptors. The thyroid seems to be a target organ. Two alteration endpoints: the thyroid histology and the muscular thyroid hormone concentrations, were used simultaneously. High concentrations in PCBs and DDT were detected in muscles, supporting the idea that the Mediterranean fauna could be more polluted than the Atlantic fauna. The high abundance of DDE indicates a progressive degradation of remnant DDT load and the absence of new inputs in this area. Aquaculture sea bass shows a significant higher amount of pollutants on fresh weight basis (especially PCBs) in their muscles compared to the wild sea bass. Those differences may be related mainly to the contaminations of diet. Thyroid parameters vary between wild and aquaculture sea bass, wild sea bass were characterized by higher follicle diameters, epithelial cell heights and muscular T4 concentrations. A significant relationship between persistent organic pollutants (muscular PCBs and DDT concentration) and the different thyroid parameters (diameters of follicles, epithelial cell heights and muscular T4 levels) could be observed, which support the hypothesis that these compounds have an adverse impact on thyroid morphometry and function. [Copyright &y& Elsevier]

The effect of carbofuran, a carbamate pesticide, on the breeding performance of the freshwater fish Labeo rohita (Hamilton) has been investigated in the present study. Breeding of L. rohita was conducted after treatment with three sublethal concentrations, i.e. 0.06, 0.15 and 0.30 mg L-1 of carbofuran for 96 h. The present investigation showed that the number of total eggs and total amount of eggs (litre per kg body weight) decreased significantly (p < 0.01) at all concentrations of carbofuran in comparison to controls, while the reduction in fertilization percentage at all concentrations of carbofuran was not significantly different from controls. The reduction in hatching percentage, the expected number of hatchlings, and the expected number of hatched larvae were significantly (p < 0.01) different between treated and control groups at all carbofuran concentrations. No significant differences for the 96 h survivability of hatched larvae were reported at all concentrations of carbofuran. [ABSTRACT FROM AUTHOR]

The relative isolation of the Mediterranean population, their feeding habits, and the widespread use of their fillets for human consumption make the Mediterranean swordfish, Xiphias gladius, an interesting species from an ecotoxicological and commercial point of views. High resolution gas chromatography and tandem mass spectrometry detected 19 PBDE congeners, perfluorooctane sulfonate (PFOS), and perfluorooctanoic acid (PFOA), hexachlorobenzene (HCB), p,p' and o,p' isomers of DDT, DDE, and DDD in all samples. The presence of PBDEs was reported for the first time in Mediterranean swordfish from the South Tyrrhenian Sea; total PBDE concentrations were 2218 ± 3291 and 612 ± 598 pg/g wet wt in the liver and in the muscle, respectively. Significant correlations were identified between BDE47 and ΣPBDE liver concentrations versus sex and sexual maturity of specimens. The lipid-normalized concentrations ratio BDEnliver/BDEnmuscle+liver suggested that this species mostly accumulates POPs in the liver. PFOS and PFOA were below the LOD (1.5 and 3 ng/g wet wt, respectively) in all the samples. The ΣDDTs was 155 ± 125 and 309 ± 273 ng/g wet wt in the muscle and the liver, respectively. The estimated daily ingestion of PBDEs and DDTs through diet was lower than the acceptable weekly intakes proposed by the World Health Organization. [ABSTRACT FROM AUTHOR]

Abstract: Effects of 40 days of exposure and 20 days of recovery response at sublethal concentration of technical grades of gamma isomer of hexachlorocyclohexane (γ-HCH, 0.025ppm, 99.8%) and dichlorodiphenyltrichloroethane (DDT, 5.0ppm) in tissue (liver, brain and ovary) bioconcentrations, gonadosomatic index (GSI) and plasma levels of estradiol-17β (E2) have been estimated during prespawning phase in the catfish Heteropneustes fossilis (Bloch). The results indicated that the tissue bioconcentrations of both HCHs (HCH isomers) and DDTs (metabolites of DDT) in liver, brain and ovary were in preferential order (liver>brain>ovary). The GSI and plasma levels of E2 were declined in response to exposure of γ-HCH and DDT. On withdrawal of exposure of pesticide there was recovery of HCHs in exposed fish for all tissues studied, whereas DDTs exposed fish showed recovery only in liver. Recovery of E2 production was also recorded in γ-HCH exposed fish whereas very little recorded in DDT exposed fish. It is suggested that HCHs and DDTs have preferential order (liver>brain>ovary) of their tissue bioconcentrations and HCH/DDT-withdrawal-dependent recovery during studied phase. [Copyright &y& Elsevier]

Abstract: Deltamethrin, a synthetic pyrethroid pesticide, potential toxic pollutant and significant direct risk to the aquatic ecosystems, was investigated in the present study for its toxic impact on adult monosex Nile tilapia on the basis of acute static bioassay test, and comparison of clinical, biochemical and haemato logical examinations with deltamethrin-free control group. The 96hLC50 value of deltamethrin for monosex tilapia was 14.6μg/L. The abnormal behavioral responses and toxic symptoms were described. Fish exposed to the higher deltamethrin concentration (15μg/L) for 96h showed significantly higher lymphocytes, total leucocytic and erythrocytic counts, haemoglobin percentage and packed cell volume content and significantly lower neutrophils compared to the control group. Deltamethrin caused adverse effects in the form of hypoproteinemia, hypoalbuminemia, hypercholesterolemia, hypoglycemia and significant increase of serum aspartate aminotransferase, alanine aminotransferase, and alkaline phosphatase activities. The results provide evidence that deltamethrin pollution may have adverse impacts and was highly toxic to monosex tilapia. [Copyright &y& Elsevier]

Studies were carried out to determine the toxicity of some selected pesticides on fresh water fish in a tropical environment. The uptake of the pesticides lindane, pentachlorophenol (PCP), and propoxur, which are frequently used on farms, and in industries as well as by loggers and timber men on wood were studied in concrete ponds at the University of Cape Coast, in Ghana. The fish used for the study were Oreochromis niloticus, Clarias gariepinus, and Chrysicthys nigrodigitatus. They were obtained from cultured ponds in the Cape Coast and Mankessim districts in the Central Region and Weija Dam, in the Greater Accra region of Ghana. Single high lethal concentration (SD) or acute treatment and cumulative/chronic (or multiple minor) lethal concentration (CD) treatment were employed in administering the pesticides to the fish via water. Gas chromatograph electron capture detector analysis was done on the dead fish to see the extent of ingestion. The LC50 values obtained for lindane on the three fish samples were as follows: Chrysicthys – 0.38 mg L−1; Oreochromis – 0.42 mg L−1, and Clarias – 1.2 mg L−1. Mortalities occurred in fish within 3–5 days of application. For the PCP on Chrysicthys, Oreochromis, and Clarias species the LC50 values were 0.42, 0.32 and 0.64 mg L−1, respectively, for over a 2- to 3-day period. For a three-time influx period of propoxur the LC50 for Chrysicthys, Oreochromis, and Clarias, were 22.0, 30.40, and 45.04 (all in mg L−1), respectively. The results obtained indicated that the pesticides had adverse effects on the general growth and reproduction of fish as shown by gonadosomatic indices. [ABSTRACT FROM AUTHOR]

Abstract: Organochlorines such as PCBs, DDTs, HCHs, CHLs and HCB were determined in pooled whole body homogenized of fish samples collected from five locations during 1998 and 2003 in order to understand their contamination status, temporal and spatial variation in Indonesian waters. PCBs and DDTs were the predominant contaminants with concentrations from 9.7 to 2700 ng/g lipid wt. and 12 to 1100 ng/g lipid wt., respectively, while HCHs (nd-24 ng/g lipid wt.), CHL compounds (nd-81 ng/g lipid wt.) and HCB (0.22–28 ng/g lipid wt.) were one to two orders of magnitude lower. Among the locations, PCBs and CHLs were higher in the samples from highly industrialized and thickly populated-locations, whereas OC pesticides such as DDTs and HCHs were particularly more prominent in suburban and rural areas. Levels of OCs observed in the waters surrounding Java Island were higher than those in Sumatra Island, implying significant use of OCs in highly populated Java Island. Concentrations of PCBs and DDTs in fish from Jakarta Bay were significantly lower in the samples collected in 2003 as compared to fish in 1998, indicating decreasing trend of these compounds in the Indonesian environment. Recent estimated average daily intakes of PCBs (0.81 μg/person/day), DDTs (1.1 μg/person/day), HCHs (0.018 μg/person/day), CHLs (0.010 μg/person/day) were much lower than the threshold values recommended by various agencies, suggesting minimal risk of this compound via fish ingestion to Indonesians. [Copyright &y& Elsevier]

Effects of different herbicides on acetylcholinesterase (AChE), catalase and TBARS formation in teleost fish (Leporinus obtusidens) were studied. Fish were exposed during 30 days at concentrations of herbicides used in rice field. AChE activity in the brain decreased significantly after exposure to the herbicides clomazone and quinclorac. However, AChE activity increased significantly in muscle tissue after exposure to clomazone, propanil and metsulfuron methyl. Fish exposed to quinclorac, propanil and metsulfuron methyl showed TBARS decreased levels in brain and muscle tissues. However, TBARS and catalase activity increased in liver tissue after clomazone and propanil exposure. This study pointed out long-term effects on AChE activity, oxidative stress and antioxidant enzyme catalase in tissues of L. obtusidens after exposure to environmentally relevant concentrations of rice field herbicides. These parameters have been used to monitor fish toxicity in rice field system. [Copyright &y& Elsevier]

Abstract: Acute toxicity to fish hepatoma cell line PLHC-1 and to juvenile rainbow trout was examined for 18 plant protection products. The main objective was to explore whether hepatoma cells could be used to predict acute toxicity in fish taking into account the mode of toxic action and compound properties. Acute fish toxicity was determined using the OECD guideline test 203 and compared to predicted baseline LC50 of acute fish toxicity calculated with a quantitative structure–activity relationship (QSAR) derived for guppy fish. Cytotoxicity was determined through the inhibition of neutral red uptake (NR50) into lysosomes and compared to predicted baseline cytotoxicity derived for goldfish GFS cells. In general, NR50 values were higher by a factor ranging from 3 to 3000 than the corresponding acute LC50. A weak correlation between NR50 and LC50 values was found (log/log: r 2 =0.62). Also the lipophilicity (log K ow) was not a good predictor for cytotoxicity (r 2 =0.43) and lethality (r 2 =0.57) of these pesticides. The neutral red assay is detecting general baseline toxicity only. Comparing LC50 data to QSAR results, the compounds can be classified to act as narcotics or reactive compounds with a specific mode of toxic action in fish. The results indicate that limitation of the neutral red assay in predicting acute fish toxicity. A promising alternative might be the assessment of toxicity in a set of in vitro systems addressing also cell-specific functions which are related to the mode of toxic action of the compound. [Copyright &y& Elsevier]

Thirteen organochlorine pesticides (OCPs) in 18 fish species from Qiantang River were firstly determined by GC-ECD. To elucidate the sources and the environment fate of these pollutants, water and sediment samples were also analyzed for OCPs contents. Total concentrations of OCPs in fish muscles ranged from 7. 43 to 143. 79ngg−1 wet weight (ww) with highest concentration recorded in sole fish (Cynoglossus abbreviatus), a benthic carnivore. The results indicated that carnivore fish have higher OCPs concentration than other fish with different feeding modes. OCPs concentration in fish was in the range of 1. 86–5. 85, 2. 65–133. 51 and 1. 94–12. 48ngg−1 for HCHs (α-, β-, γ-, δ-HCH), DDTs (p,p′-DDD, p,p′-DDE, p,p′-DDT, o,p′-DDD) and other OCPs (aldrin, diedrin, endrin, heptachlor, heptachlor expoide), respectively. The highest OCPs concentration in fish organs of four big fish species was found in brain of silver carp (Hypophthalmichthys molitrix), 289. 26ngg−1 ww followed by kidney, liver, heart and gill. Among the OCPs analyzed, DDE, γ-HCH and heptachlor were the predominant contaminants in fish muscle, which indicated that there was recent input of lindane. Significant correlation was observed between concentrations of DDTs and lipid content as well as between OCPs and lipid contents in fish species. Both field water bioconcentration factors (BCF) and sediment BCF showed a positive correlation with octanol-water partition coefficients (K ow) in the sole fish. [Copyright &y& Elsevier]

Toxicity tests using adult specimens of Jenynsia multidentata were carried out during 96 hours in order to determine the lethal concentration (LC50) of endosulfan. Histological alterations were determined in gills and liver. Gill damage was quantified as secondary lamellae thickness. The 96 hr LC50 values were significantly different between males (0.719 μ g.L- 1) and females (1.317 μg.L- 1). The sex difference was attributed to the dimorphism in the lipid content in females (2.16%) and males (1.79%). Histological alterations in gills included hypertrophy and lifting of the epithelium of the secondary lamellae and aneurisms. These alterations caused a significant increase of the secondary lamellae thickness in treatment versus control fish. Finally, reversible histological alterations (such as hydropic degeneration and dilation of sinusoids) were observed in the liver of exposed fish as well as an irreversible change such as necrosis at the highest concentrations. [ABSTRACT FROM AUTHOR]

The Grenland fjords, southern Norway, have been heavily contaminated by dibenzo- p -dioxins and dibenzofurans (dioxins) over decades through inputs from a magnesium smelter. Despite radically decreased inputs since 1990, there are still high levels of dioxins in both biotic and abiotic components of the fjords. The aim of the study was to establish whether biomarkers’ responses in three fish species, Atlantic cod ( Gadus morhua L.), sea-trout (anadromous brown trout, Salmo trutta L.) and flounder ( Platichthys flesus L.), could be used to discern the effects in the most contaminated ecosystem, Frierfjord, from the effects in the adjacent, less-contaminated ecosystem, Eidangerfjord. Biomarker responses clearly indicated that the three fish species were affected by dioxin exposure. Phase I responses in cod and trout could be used to differentiate exposure in the two fjord ecosystems. Phase II responses (glutathione S -transferase) in cod and trout similarly indicated a higher dioxin exposure in Frierfjord compared with Eidangerfjord. Results for glutathione S -transferase and glutathione reductase indicated different exposure levels in the two fjords, but also showed seasonal variability, and the results highlighted the need for baseline data for these biomarkers. [ABSTRACT FROM AUTHOR]

The article examines the organochlorine (OC) residues in fish and water samples from Lake Victoria, Uganda. Organochlorine pesticides are halogenated organic compounds classified as dichlorodiphenyl-ethanes, hexachlorocyclohexanes, cyclodienes, and chlorinated benzenes. It compares the levels of OC with some cited extraneous residue limits. The researchers have found variations in pesticide dynamics in the tropical and subtropical environment compared with a temperate environment. However, due to their bioaccumulation tendencies and their ubiquitous nature, resulting from global transport and redeposition, the use of OCs has global implications.

No abstract available. [ABSTRACT FROM AUTHOR]

Accumulation, distribution and metabolism of ring labelled, 14C-1,1,1, - trichloro-2,2-bis(p-chlorophenyl)ethane (p,p'-DDT) in a model marine aquatic ecosystem consisting of sea water, sediment, oysters (Isognomonon alatus) and Humbug fish (Dascillus aruanus) were studied in the laboratory. 14C-p,p'-DDT distributes rapidly in the ecosystem immediately after application on the water surface with reduction of its concentration in the water phase from 1.18 ng g-1 to 0.71 ng g-1 after 2 hours and an increase in its content in the sediment and oysters. The bioconcentration factor reached a maximum of 19 103 in oysters, and 1657 in Humbug fish after 24 hours. The sediment concentration reached 117 ng g-1 after 168 hours from start of application. A peak bioconcentration factor of 111 103 was calculated after 120 hours when 0.24 mg kg-1 of 14C-p,p'-DDT was maintained through dosing every 24 hours with 0.002 mg kg-1 of a mixture of labelled and non-labelled pesticide. The rate of depuration of accumulated 14C-p,p'-DDT sediment residues was up to 78.3% after 24 hours while oysters lost only 14.0% during the same period. The loss in Humbug fish was only 22.2% in three days. Volatilisation and sorption losses from seawater alone (without sediment/biota) were found to be very high in the range of 73.8 - 91.5% over 24 h for p,p'-DDT in aerated and non-aerated ecosystem. Gas chromatograph and TLC analysis of water, sediment and oyster samples revealed presence of p,p'-DDT and substantial amounts of p,p'-DDE and p,p'-DDD three days after pesticide dosage. [ABSTRACT FROM AUTHOR]

The concentrations of organochlorine residues of lindane, aldrin, ∞- endosulfan, dieldrin, endrin, p,p'-DDE, p,p'-DDD and p,p'-DDT in samples of seawater, sediment, fish and seaweed from different locations along the coast of Kenya are discussed in relation to the geographical location of the sampling sites and potential sources of residue over a period of two years. All sediment samples were found to contain very low levels of organic carbon except those sampled from Sabaki River that had high (4.7%) organic carbon due to greater primary activity. Most of the pesticides residues (112 samples analysed in 1997 and 258 analysed in 1998/99) were detected in fish, water, sediments and seaweed. The concentration of some residues was higher during the wet season than the dry season in 1997, but no marked seasonal variation was observed in 1998/99. Lindane, aldrin, p,p'-DDT and p,p'-DDE were the most frequently observed residues in all samples while ∞-endosulfan, dieldrin, p,p'-DDD and endrin were either present in low concentrations or absent in most samples. Water samples had the lowest concentrations of residues (range 0.503 - 9.025 ng g-1). Sediments had the second highest levels of pesticides residues with a range of 0.584 - 59.00 ng g-1 while fish lipid content had the highest levels of residues in 1989/99 with p,p'-DDT concentration of 1011 ng g-1 and 418 ng g-1 p,p'-DDD in Siganus rivulatus. [ABSTRACT FROM AUTHOR]

Studies the concentrations of pesticide residues in tissues of fish from Kolleru Lake in India. Analysis of fish samples through modified method proposed for gas chromatographic determination for the pesticides; Information on extraction efficiency and maximum concentrations of pesticides residues; Evaluation of the baseline data and pesticide pollution in ecosystem of the lake.

The article presents a study which investigates the effects of the pesticide chlordecone (CD) on the gonads of freshwater catfish, Heteropneustes fossilis. The study performed a static acute toxicity bioassay to determine the lethal concentration 50 (LC50) value of CD. Moreover, the study revealed that the fish suffered extensive damage in the testes after exposure to CD.

The article presents a study which describes lepidological changes in the freshwater snakehead Channa punctatus (Bloch) upon exposure to organochlorine pesticide endosulfan. The study used adult fishes that were bought from local waterbody and transported to the laboratory. Moreover, the study revealed that lepidonts (L) start to develop after the circulus involved has been fully developed.

The article presents a study on the effects of sublethal concentrations of diuron to the erythropoietic activities, red blood cells (RBC), packed cell volume (PCV), and hemoglobin (Hb) of tilapia (Sarotherodon mossambicus). The study used male tilapia, ultraviolet (UV) assay, continuous assay, and analysis of variance (ANOVA). Results showed that diuron reduced RBC and erythropoietic activity.

The article presents a study on the acute toxicity of several pesticides on Brachionus calyciflorus and Brachionus plicatilis. The study utilized various pesticides including trichlorfon, fenitrothion, and lindane, in which acute toxicity bioassays were conducted. The results showed that Brachionus plicatilis is more resistant to pesticides compared to Brachionus calyciflorus, wherein the most toxic compound was fenitrothion.

The article presents a study which evaluates the implication of lindane, a synthetic organic pesticide, on the blood metabolism of the fish Anguilla anguilla. The study sampled the fishes for various biochemical parameters, wherein the treatment toxic effect was determined through a one-way analysis of variance (ANOVA). The results showed that lindane intoxication had an impact on the variations in biochemical compositions of blood in fish.

The article presents a study on the implication of the organophosphate pesticide fenitrothion on the neurobehavior of the freshwater fish Channa punctatus. The study conducted toxicity tests on the 20-Liter (L) tapwater, wherein the water containing test fishes was added with fenitrothion dissolved in alcohol. The results showed that fishes exposed to fenitrothion demonstrated enhanced surfacing activity.

The article presents a study on the effect of pesticides, surfactants, and heavy metals on heme oxygenase activity and metal-binding proteins (MBP) of Cyprinus carpio Linné, a freshwater red carp. The study conducted experiments on red carp which were injected with various chemicals and were killed three days after the injection. Results showed that the content of MBP in the hepatopancreas and kidney has increased, while heme oxygenase was greatly stimulated in the hepatopancreas.

The article presents a study which examines the comparative ovarian pathology of several pesticides, such as methoxychlor, aldrin, and monocrotophos, in Puntius conchonius Hamilton teleost. Study used long-term static bioassays and tap water as a dilution fluid. Study reveals that the concentrations of the pesticides neither caused visible stress nor fish kill in four months experimental period. Study shows that organophosphate pesticides may become hazardous to fish in long period of exposure.

The article presents a study on the changes in the biochemical parameters of freshwater fish Tilapia mossambica blood and kidney under intoxication to pesticide heptachlor. The study applied bioassays with heptachlor in static waters. Results showed that carbohydrate content in heptachlor intoxicated T. mossambica decreased due to the tissue utilization of carbohydrates.