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1.
Several organisms have been used as indicators, bio-monitoring agents or test organisms in ecotoxicological studies. A close relative of the well established Japanese medaka, the Java medaka (Oryzias javanicus), has the potential to be a test organism. The fish is native to the estuaries of the Malaysian Peninsula, Thailand, Indonesia and Singapore. In this study, newly fertilised eggs were exposed to different concentrations of Cd and Hg. Observations were done on the development of the embryos. Exposure to low levels of Cd and Hg (0.01-0.05 ppm) resulted in several developmental disorders that led to death. Exposure to ≥1.0 ppm Cd resulted in immediate developmental arrest. The embryos of Java medaka showed tolerance to a certain extent when exposed to ≥1.0 ppm Hg compared to Cd. Based on the sensitivity of the embryos, Java medaka is a suitable test organism for ecotoxicology in the tropical region.  相似文献   

2.
《Marine pollution bulletin》2012,64(5-12):347-349
Several organisms have been used as indicators, bio-monitoring agents or test organisms in ecotoxicological studies. A close relative of the well established Japanese medaka, the Java medaka (Oryzias javanicus), has the potential to be a test organism. The fish is native to the estuaries of the Malaysian Peninsula, Thailand, Indonesia and Singapore. In this study, newly fertilised eggs were exposed to different concentrations of Cd and Hg. Observations were done on the development of the embryos. Exposure to low levels of Cd and Hg (0.01–0.05 ppm) resulted in several developmental disorders that led to death. Exposure to ⩾1.0 ppm Cd resulted in immediate developmental arrest. The embryos of Java medaka showed tolerance to a certain extent when exposed to ⩾1.0 ppm Hg compared to Cd. Based on the sensitivity of the embryos, Java medaka is a suitable test organism for ecotoxicology in the tropical region.  相似文献   

3.
《Marine pollution bulletin》2012,64(5-12):309-317
Oryzias melastigma, also called O. dancena, is becoming a very useful model for estuarine and marine ecotoxicity studies. With O. melastigma being adopted by ILSI Health and Environmental Science Institute (HESI) for embryo toxicity testing, improved knowledge of biomarker based embryonic development becomes especially important for mechanism-based toxicity evaluations. Using whole mount in situ hybridization and immunostaining techniques together with widely used molecular markers, this study describes the molecular development of marine medaka embryos, focusing on the brain, eye, heart, pectoral fin, pancreas, liver, muscle and neuron system. These organs are targets of environmental pollutants that disrupt normal embryonic development in medaka and other fish.  相似文献   

4.
Oryzias melastigma, also called O. dancena, is becoming a very useful model for estuarine and marine ecotoxicity studies. With O. melastigma being adopted by ILSI Health and Environmental Science Institute (HESI) for embryo toxicity testing, improved knowledge of biomarker based embryonic development becomes especially important for mechanism-based toxicity evaluations. Using whole mount in situ hybridization and immunostaining techniques together with widely used molecular markers, this study describes the molecular development of marine medaka embryos, focusing on the brain, eye, heart, pectoral fin, pancreas, liver, muscle and neuron system. These organs are targets of environmental pollutants that disrupt normal embryonic development in medaka and other fish.  相似文献   

5.
Static bioassay tests were carried out on Channa punctatus Bloch in the laboratory after renewal of concentrations every 24 h. The LC50 values and 95 per cent confidence limits were 45.21 (39.62 … 51.11) ppm at 12 h and 29.8 (27.49 … 31.95) ppm of Zn at 96 h of exposure. The actual dissolution values of zinc were also determined in test solutions using an atomic absorption spectrophotometer. Behavioural changes were the higher rate of opercular movements, surfacing, loss of equilibrium and haemorrhage near mouth and caudal fin. The LT50 values indicate that survival was increased with decreasing Zn concentration. The histopathological changes observed due to Zn toxicity in the gills have been discussed in relation to fish mortality.  相似文献   

6.
Embryos and juveniles of the sheepshead minnow (Cyprinodon variegatus), a saltwater fish, were exposed to ammonium jarosite, a waste product of the processing of zinc ore, during a 28-day posthatch, flow-through toxicity test. Exposure to measured ammonium jarosite concentrations ≤ 290 ppm had no significant effect on the hatching success of embryos. However, slight delays in hatching were observed in test concentrations ≥ 140 ppm. Although exposure to test concentrations ≥ 140 ppm significantly decreased the ability of juvenile fish to uncurl after hatching, juvenile mortality was significantly increased only in test concentrations ≥ 230 ppm. There was no effect on growth of juvenile fish in jarosite concentrations ≤ 230 ppm. The estimated maximum acceptable toxicant concentration (MATC), based on measured concentrations, was > 140< 230 ppm.  相似文献   

7.
Polycyclic aromatic hydrocarbons (PAHs) are widespread persistent pollutants that readily undergo biotic and abiotic conversion to numerous transformation products in rivers, lakes and estuarine sediments. Here we characterize the developmental toxicity of four PAH transformation products each structural isomers of hydroxynaphthoic acid: 1H2NA, 2H1NA, 2H3NA, and 6H2NA. Medaka fish (Oryzias latipes) embryos and eleutheroembryos were used to determine toxicity. A 96-well micro-plate format was used to establish a robust, statistically significant platform for assessment of early life stages. Individual naphthoic acid isomers demonstrated a rank order of toxicity with 1H2NA>2H1NA>2H3NA>6H2NA being more toxic. Abnormalities of circulatory system were most pronounced including pericardial edema and tube heart. To determine if HNA isomers were AhR ligands, spatial-temporal expression and activity of CYP1A was measured via in vivo EROD assessments. qPCR measurement of CYP1A induction proved different between isomers dosed at respective concentrations affecting 50% of exposed individuals (EC50s). In vitro, all ANH isomers transactivated mouse AhR using a medaka CYP1A promoter specific reporter assay. Circulatory abnormalities followed P450 induction and response was consistent with PAH toxicity. A 96-well micro-plates proved suitable as exposure chambers and provided statistically sound evaluations as well as efficient toxicity screens. Our results demonstrate the use of medaka embryos for toxicity analysis thereby achieving REACH objectives for the reduction of adult animal testing in toxicity evaluations.  相似文献   

8.
Polycyclic aromatic hydrocarbons (PAHs) are widespread persistent pollutants that readily undergo biotic and abiotic conversion to numerous transformation products in rivers, lakes and estuarine sediments. Here we characterize the developmental toxicity of four PAH transformation products each structural isomers of hydroxynaphthoic acid: 1H2NA, 2H1NA, 2H3NA, and 6H2NA. Medaka fish (Oryzias latipes) embryos and eleutheroembryos were used to determine toxicity. A 96-well micro-plate format was used to establish a robust, statistically significant platform for assessment of early life stages. Individual naphthoic acid isomers demonstrated a rank order of toxicity with 1H2NA > 2H1NA > 2H3NA > 6H2NA being more toxic. Abnormalities of circulatory system were most pronounced including pericardial edema and tube heart. To determine if HNA isomers were AhR ligands, spatial-temporal expression and activity of CYP1A was measured via in vivo EROD assessments. qPCR measurement of CYP1A induction proved different between isomers dosed at respective concentrations affecting 50% of exposed individuals (EC50s). In vitro, all ANH isomers transactivated mouse AhR using a medaka CYP1A promoter specific reporter assay. Circulatory abnormalities followed P450 induction and response was consistent with PAH toxicity. A 96-well micro-plates proved suitable as exposure chambers and provided statistically sound evaluations as well as efficient toxicity screens. Our results demonstrate the use of medaka embryos for toxicity analysis thereby achieving REACH objectives for the reduction of adult animal testing in toxicity evaluations.  相似文献   

9.
Embroygenesis of the three coregonid forms Blaufelchen, Gangfisch, and Sandfelchen from Lake Constance was observed at five different constant temperatures in a static incubation system. The relationship between temperature and the time to reach 14 developmental stages from fertilization to hatching was established for the three forms. Relative to the total incubation time, pectoral fin flutter and eye movement start earliest in Gangfisch and latest in Blaufelchen. This might allow Gangfisch to tolerate lower oxygen concentrations during the last phase of embryogenesis than Blaufelchen. Developmental rates per day as a function of temperature can be calculated by a power function. A model is presented which permits to predict the time of mass hatching for embryos which are incubated at fluctuating temperatures. The total incubation times for the three coregonids of Lake Constance are short as compared to those of other coregonids. This is interpreted as an adaptation to the specific thermal environment of each coregonid stock which helps to ensure larval survival in the respective habitat.  相似文献   

10.
Oxygen fluxes through artificially created salmon redds within four UK rivers were quantified and assessed against survival to hatching of Atlantic salmon embryos. All sites recorded high spatial variability in survival. Minimum survival to hatching was zero at all sites. Maximum survival to hatching ranged from 35% to 91%. Mean survival to hatching ranged from 8·7% to 71%. Intra‐ and inter‐site variations in rates of oxygen supply were observed. Generally, interstitial dissolved oxygen concentrations declined over the incubation period from a maximum recorded directly after redd creation, although localized fluctuations were recorded. Similarly, interstitial flow velocities declined over the incubation period from a maximum directly after redd creation to a minimum at hatching. With respect to the causes of embryo mortalities, oxygen supply was shown to be a stronger determinant of survival than interstitial oxygen concentration or interstitial flow velocity. To improve delineation of potential causes of embryo mortalities in the field, the statistical analysis was integrated within mass transfer theory of the processes controlling respiration to determine the likely mechanisms inhibiting respiration. Based on this analysis, mortalities were assessed to have resulted from periods of lethal oxygen concentrations, from periods of interstitial flow velocities that were insufficient to remove metabolic waste, or from combinations of oxygen concentration and interstitial flow that did not support respiratory requirements. A set of oxygen‐supply‐related thresholds for assessing incubation habitat quality are proposed. Copyright © 2007 John Wiley & Sons, Ltd.  相似文献   

11.
Lebistes reticulatus (Peters) was exposed to various concentrations of phenol, pentachlorophenol and sodium pentachlorophenolate to determine their toxicity, lethal concentrations and slope functions by a static bioassay procedure. Simultaneous controls were also run. The 94h LC50 values were 47.5mg/l (42.04 … 53.68) for phenol, 0.77 mg/l (0.616 … 0.963) for sodium pentachlorophenate and 0.97 mg/l (0.866 … 1.086) for pentachlorophenol. On this basis, the rank order is sodium pentachlorophenolate-pentachlorophenol-phenol. During the treatment, fish showed an abnormal swimming reflex, excessive mucus secretion, haemorrhage near lips, abdomen and basis of fins and loss of equilibrium followed by death.  相似文献   

12.
In order to examine the biological effects by TBT exposure, experiments involving the exposure of five levels of TBT concentrations (0, 10, 100, 1000 and 10,000 ngl(-1)) were conducted on the caprellid amphipod Caprella danilevskii, over a generation after hatching. Marked delays in growth and molting during the early developmental stage and maturation were found in both 100 and 1000 ng TBTCl l(-1) concentrations in spite of the sex. All specimens died in 10,000 ng TBTCl l(-1) within 4 days after hatching. Inhibition of maturation and reproduction such as delaying in the achievement of maturity and a decrease in the number of juveniles hatched was apparent in 10 and 100 ng TBTCl l(-1) concentrations. Furthermore, brood loss, and failure in egg formation and hatching were observed as the TBT concentration became higher. No significant changes in sex ratio were seen at any of the TBT exposure levels during hatching and maturation in the present study. This phenomenon was different from a previous study in which the proportion of females was increased with an increase in TBT concentrations in the embryonic exposure experiment. This suggests that sex disturbance is induced during the embryonic stage of the species. A drastic decrease in survival rate was observed at 10 ng TBTCl l(-1) (25%) which corresponds to the mean level in coastal waters. Therefore, the present encountering ambient TBT concentration may influence populations of C. danilevskii in the coastal environment.  相似文献   

13.
Irgarol 1051 is a s-triazine herbicide used in popular slime-resistant antifouling paints. It has been shown to be acutely toxic to corals, mangroves and sea grasses, inhibiting photosynthesis at low concentrations (>50 ng l(-1)). We present the first data describing the occurrence of Irgarol 1051 in coastal waters of the Northeastern Caribbean (Puerto Rico (PR) and the US Virgin Islands (USVI)). Low level contamination of coastal waters by Irgarol 1051 is reported, the herbicide being present in 85% of the 31 sites sampled. It was not detected in water from two oceanic reference sites. In general, Irgarol 1051was present at concentrations below 100 ng l(-1), although far higher concentrations were reported at three locations within Benner Bay, USVI (223-1,300 ng l(-1)). The known toxicity of Irgarol 1051 to corals and sea grasses and our findings of significant contamination of the Northeastern Caribbean marine environment by this herbicide underscore the importance of understanding, more fully, local and regional exposure of reef and sea grass habitats to Irgarol 1051 and, where necessary, implementing actions to ensure adequate protection of these important ecosystems.  相似文献   

14.
Regeneration of partially amputated caudal fin was studied in freshwater fish Oreochromis mossambicus exposed to sublethal concentrations of zinc (5.0 mg L—1 and 10.0 mg L—1) under ambient laboratory conditions over a period of 20 days. Caudal fin regeneration was measured on 5th, 10th, 15th and 20th day of exposure and after amputation. Significant ( p < 0.05) retardation in fin regeneration was observed on day 5th and 10th in fish exposed to the nominal concentration of 5.0 mg L—1 Zn, while retardation was found highly significant ( p < 0.01) at all the observations in 10.0 mg L—1. The maximum inhibition in caudal fin regeneration (20.8 % and 24.3 %) was found during the initial observation at both of the concentrations (5.0 mg L—1 and 10.0 mg L—1) of zinc exposure. Later on the regeneration rate was almost as good as in the control group. Thus in this study fin regeneration was significantly inhibited at all time points following Zn exposure as a detrimental effect of Zn to fish. This study demonstrates that fish caudal fin regeneration is a simple assay, sensitive and easy to perform, and can serve as a model to determine the toxicity of pollutants in aquatic environment.  相似文献   

15.
Glyphosate is one of the most widely applied herbicides globally but its persistence in seawater has not been reported. Here we quantify the biodegradation of glyphosate using standard “simulation” flask tests with native bacterial populations and coastal seawater from the Great Barrier Reef. The half-life for glyphosate at 25 °C in low-light was 47 days, extending to 267 days in the dark at 25 °C and 315 days in the dark at 31 °C, which is the longest persistence reported for this herbicide. AMPA, the microbial transformation product of glyphosate, was detected under all conditions, confirming that degradation was mediated by the native microbial community. This study demonstrates glyphosate is moderately persistent in the marine water under low light conditions and is highly persistent in the dark. Little degradation would be expected during flood plumes in the tropics, which could potentially deliver dissolved and sediment-bound glyphosate far from shore.  相似文献   

16.
Short-term tests of the acute toxicity of Cu2+ (from copper sulphate) to a freshwater ostracod, Cypris subglobosa SOWERBY were carried out at five different pH values from 5.5 to 8.5. The toxicity of copper abruptly decreased with an increase in pH of the Cu-containing medium. The 48 h EC50 value of Cu increased from 0.35 ppm at pH =5.5… 5.1 ppm at pH =8.5. The per cent survival, median period of immobilization (ET50), slope functions and the 95 per cent confidence limits were determined at each pH level. The direct correlation between EC50 value and pH indicated that the acute toxicity of Cu decreased as the pH increased from 5.5… 8.5.  相似文献   

17.
A novel phytotoxicity assay was incorporated into an environmental assessment of Hervey Bay and the Great Sandy Straits, to investigate the role of run-off associated herbicides in the deteriorated health of intertidal seagrass meadows. Dose response curves of common herbicides were performed and their toxicity equivalents elucidated to assist in analysis. The results of the assay were reproducible and corresponded strongly with results of chemical analyses. The incorporation of the assay into the assessment of surface waters added an important aspect to the study by allowing investigation of the toxicity of cumulative herbicide concentrations and yielding biologically relevant data. The highest herbicide concentration detected during the study was equivalent to 0.23 microg l(-1) diuron; a concentration known to inhibit photosynthetic efficiency of the assay biomaterial by approximately 3%.  相似文献   

18.
Since 1990s, various booster biocides have been increasingly used as substitutes of organotins. However, knowledge about their toxicities on tropical/sub-tropical marine species is significantly lacking. This study comprehensively investigated the acute toxicities of copper, tributyltin (TBT), and five commonly used booster biocides including Irgarol, diuron, zinc pyrithione (ZnPT), copper pyrithione (CuPT) and chlorothalonil on the growth or survival of 12 marine species in which eight of them are native species of subtropical Hong Kong. We found that Irgarol was more toxic than TBT on the growth of autotrophic species. The toxicity of CuPT was comparable to that of TBT on almost all test species, while it showed higher toxicity than TBT on medaka fish larvae. As the usage of these biocides is expected to further increase worldwide, accurate assessments of their ecological risks are required for better informed decision on their management. This study provided useful datasets for such purposes.  相似文献   

19.
《Marine pollution bulletin》2009,58(6-12):473-478
Photosystem II (PSII) herbicides have been shown to affect the photosynthesis of corals at low, environmentally relevant concentrations. The recent detection of the PSII herbicide Irgarol-1051 in coastal waters of Hong Kong at concentrations above the EC50 for reduction of photosynthesis of corals prompted further investigation into the extent of PSII herbicide pollution in coral reefs of Hong Kong. Snap-shot and passive samples were taken from coral reef sites and evaluated via HPLC/MS–MS and a novel bioanalytical technique. Low concentrations (less than 10 ng L−1) of diuron and atrazine were found at all study sites. Extracts from these samples concentrated by a factor of 10 were found to reduce the photosynthetic yield of zooxanthellae. It appears unlikely that herbicide pollution is a key issue in isolation but may act synergistically with other stressors to reduce the viability of Hong Kong’s coral reefs. The study has also demonstrated the feasibility of combining sample extraction techniques with a coral specific bioanalytical technique for a sensitive assessment of risks associated with herbicide exposure in corals.  相似文献   

20.
Alkylated polycyclic aromatic hydrocarbons (alkyl-PAHs) are the predominant form of PAHs in oil, comprising 85–95% of total PAHs. However, little attention has been paid to these chemicals in ecological risk assessment of marine oil spill. A comparative study of the toxic effects of phenanthrene and retene (7-isopropyl-1-methylphenanthrene, an alkyl-phenanthrene) on the early life stage of marine medaka (Oryzias melastigma) was conducted. Results showed that retene was significantly more toxic than phenanthrene, and marine medaka could be more sensitive to retene than some freshwater fishes. Retene had a higher excretion rate than phenanthrene during the larvae stage. Both of compounds resulted in developmental malformation of marine medaka embryos, with phenanthrene affecting on peripheral vascular system and yolk sac, while retene affecting on cardiac tissues. The toxicity of phenanthrene might be mainly related to its anesthetic effects, and that of retene might be related to the CYP1A-mediated toxicity of its metabolites.  相似文献   

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