Sumithion is widely used to control brittle in paddy fields and tiger bug in fish larval rearing ponds. The objective of this study was to elucidate the toxic effects of sumithion on larval stages of stinging catfish ...Sumithion is widely used to control brittle in paddy fields and tiger bug in fish larval rearing ponds. The objective of this study was to elucidate the toxic effects of sumithion on larval stages of stinging catfish Heteropneustes fossilis. Larvae were exposed to two concentrations(150 and 250 μg/L) of sumithion with one control in three replicates of each. Larvae samples were collected at 20- and 24-h intervals followed by observation under a digital microscope. Exposures of stinging catfish larvae to sumithion produced deformities including irregular head shape, lordosis, yolk sac edema, body arcuation, tissue ulceration, etc. The mortality rates of larvae were significantly increased in response to increase in sumithion concentrations. Furthermore, around 30% of the total adult stinging catfish reared in sumithiontreated aquaculture ponds were found to be deformed permanently. These findings highlight that exposure of stinging catfish to sumithion at the critical and sensitive stages in their life cycle may significantly reduce the number of returning adults. Therefore, the use of sumithion for crop protection needs to be considered carefully and alternatives to sumithion should to be developed for controlling aquatic insects in aqua-ponds during larval rearing.展开更多
With the increased use of copper （Cu）-based antifouling （AF） paints, copper has become a potential threat to marine organisms. Experiments were performed to investigate the effects of copper on larvae of the barna...With the increased use of copper （Cu）-based antifouling （AF） paints, copper has become a potential threat to marine organisms. Experiments were performed to investigate the effects of copper on larvae of the barnacle Chthamalus challengeri. These experiments attempted to identify a more sensitive index to monitor copper pollution in marine environments. The 24 h LC_50 ranged from 156.07 μg/L （nauplius Ⅱ） to 817.15μg/L （cypris） and the no observed effect concentration （NOEC） ranged from 81.75 μg/L （nauplius Ⅱ） to 571.04 μg/L （cypris）. The cypris settlement rate declined significantly when copper concentrations 〉135 μg/L. No cypris was found in the copper concentration of 60 and 75 μg/L treatment groups stressed for 22 d. Nauplius Ⅱ moulting was not affected by exposure to copper for 24 h; however, when extended to 48 h, the percent moulted in 75 μg/L treatment group was declined to 37.12%, which was significant lower （P〈0.05） than that in the control group. The phototaxis of nauplius II decreased significantly when copper concentrations _〉45 μg/L. Despite an initial significant increase at copper concentrations of 30 μg/L, ammonia excretion rate decreased when copper concentrations ≥60 μg/L. These results suggested that： （1） nauplius Ⅱ could not develop to the cypris when the copper concentration ≥60 μg/L; （2） cypris settlement is more susceptible to copper than cypris mortality rate; （3） nauplius II is the most sensitive larval stage; （4） nauplius II ammonia excretion rate is the most sensitive index to copper and might be as the indicator for copper pollution monitoring.展开更多
As the most widely used plasticizers in the world, phthalate esters （PAEs） are potential endocrine disruption compounds （EDCs）. In the present study, the toxicity of dimethyl phthalate （DMP）, diethyl phthalate ...As the most widely used plasticizers in the world, phthalate esters （PAEs） are potential endocrine disruption compounds （EDCs）. In the present study, the toxicity of dimethyl phthalate （DMP）, diethyl phthalate （DEP）, dibutyl phthalate （DBP）, di （2-ethylhexyl） phthalate （DEHP） on embryogenesis and larvae development of the marine univalve Haliotis diversicolor supertexta was examined in laboratory. The results show that the malformation of embryos appeared during the experiment, such as embryos died or lysed, small transparent flocculent rings studded on the periphery of the embryo, and the larvae could failed to hatch. In embryo toxic test, embryos incubated at the highest concentration of DMR DEP and DBP solutions showed significantly high abnormal rate compared with the control, while DEHP solutions displayed no significant difference. In larval toxic test, in all concentrations of DMP, DEP and DBP solutions, larval settlement rates were low significantly than that of the control. Similarly, DEHP solutions show nearly no effect on the larval settlement. The order of toxicity on embryos and larvae is DBP〉DEP〉DMP〉DEHE Being a simple and easy stimulation to indoor spawn, sensitive to environmental factors, and short culture time, the embryos of H. diversicolor supertexta can be used to indicate toxicity of the PAEs.展开更多
Acetamiprid is a novel neonicotinoid insecticide invented by Nippon Soda Co., Ltd.. To explore the possibility of acetamiprid as larvicide of mosquitoes, lethal and sublethal effects of acetamiprid on the larvae of ...Acetamiprid is a novel neonicotinoid insecticide invented by Nippon Soda Co., Ltd.. To explore the possibility of acetamiprid as larvicide of mosquitoes, lethal and sublethal effects of acetamiprid on the larvae of Culex pipiens pallens were studied by immersion method in the laboratory. The results indicated that the larvae of Culex pipiens pallens were sensitive to acetamiprid. The mortality of larvae peaked at 72 h after treatment. The 1st instar larvae was the most susceptible to acetamiprid, and the 4th instar larvae was the most tolerant to acetamiprid, the LC 50 values were 0.020 mg/L and 0.296 mg/L at 72 h after treatment, respectively. Sublethal concentrations of acetamiprid could delay the development of larvae and decrease the weight of pupa. We suggested that acetamiprid is a safe and effective substitute for the using larvicides of mosquitoes.展开更多
文摘Sumithion is widely used to control brittle in paddy fields and tiger bug in fish larval rearing ponds. The objective of this study was to elucidate the toxic effects of sumithion on larval stages of stinging catfish Heteropneustes fossilis. Larvae were exposed to two concentrations(150 and 250 μg/L) of sumithion with one control in three replicates of each. Larvae samples were collected at 20- and 24-h intervals followed by observation under a digital microscope. Exposures of stinging catfish larvae to sumithion produced deformities including irregular head shape, lordosis, yolk sac edema, body arcuation, tissue ulceration, etc. The mortality rates of larvae were significantly increased in response to increase in sumithion concentrations. Furthermore, around 30% of the total adult stinging catfish reared in sumithiontreated aquaculture ponds were found to be deformed permanently. These findings highlight that exposure of stinging catfish to sumithion at the critical and sensitive stages in their life cycle may significantly reduce the number of returning adults. Therefore, the use of sumithion for crop protection needs to be considered carefully and alternatives to sumithion should to be developed for controlling aquatic insects in aqua-ponds during larval rearing.
基金Supported by the National Natural Science Foundation of China(No.3107045820)the State Oceanic Administration Public Welfare Project(Nos.201305009,201305009-4,201005007)
文摘With the increased use of copper （Cu）-based antifouling （AF） paints, copper has become a potential threat to marine organisms. Experiments were performed to investigate the effects of copper on larvae of the barnacle Chthamalus challengeri. These experiments attempted to identify a more sensitive index to monitor copper pollution in marine environments. The 24 h LC_50 ranged from 156.07 μg/L （nauplius Ⅱ） to 817.15μg/L （cypris） and the no observed effect concentration （NOEC） ranged from 81.75 μg/L （nauplius Ⅱ） to 571.04 μg/L （cypris）. The cypris settlement rate declined significantly when copper concentrations 〉135 μg/L. No cypris was found in the copper concentration of 60 and 75 μg/L treatment groups stressed for 22 d. Nauplius Ⅱ moulting was not affected by exposure to copper for 24 h; however, when extended to 48 h, the percent moulted in 75 μg/L treatment group was declined to 37.12%, which was significant lower （P〈0.05） than that in the control group. The phototaxis of nauplius II decreased significantly when copper concentrations _〉45 μg/L. Despite an initial significant increase at copper concentrations of 30 μg/L, ammonia excretion rate decreased when copper concentrations ≥60 μg/L. These results suggested that： （1） nauplius Ⅱ could not develop to the cypris when the copper concentration ≥60 μg/L; （2） cypris settlement is more susceptible to copper than cypris mortality rate; （3） nauplius II is the most sensitive larval stage; （4） nauplius II ammonia excretion rate is the most sensitive index to copper and might be as the indicator for copper pollution monitoring.
基金Supported by National Natural Science Foundation of China (No. 40476057)
文摘As the most widely used plasticizers in the world, phthalate esters （PAEs） are potential endocrine disruption compounds （EDCs）. In the present study, the toxicity of dimethyl phthalate （DMP）, diethyl phthalate （DEP）, dibutyl phthalate （DBP）, di （2-ethylhexyl） phthalate （DEHP） on embryogenesis and larvae development of the marine univalve Haliotis diversicolor supertexta was examined in laboratory. The results show that the malformation of embryos appeared during the experiment, such as embryos died or lysed, small transparent flocculent rings studded on the periphery of the embryo, and the larvae could failed to hatch. In embryo toxic test, embryos incubated at the highest concentration of DMR DEP and DBP solutions showed significantly high abnormal rate compared with the control, while DEHP solutions displayed no significant difference. In larval toxic test, in all concentrations of DMP, DEP and DBP solutions, larval settlement rates were low significantly than that of the control. Similarly, DEHP solutions show nearly no effect on the larval settlement. The order of toxicity on embryos and larvae is DBP〉DEP〉DMP〉DEHE Being a simple and easy stimulation to indoor spawn, sensitive to environmental factors, and short culture time, the embryos of H. diversicolor supertexta can be used to indicate toxicity of the PAEs.
文摘Acetamiprid is a novel neonicotinoid insecticide invented by Nippon Soda Co., Ltd.. To explore the possibility of acetamiprid as larvicide of mosquitoes, lethal and sublethal effects of acetamiprid on the larvae of Culex pipiens pallens were studied by immersion method in the laboratory. The results indicated that the larvae of Culex pipiens pallens were sensitive to acetamiprid. The mortality of larvae peaked at 72 h after treatment. The 1st instar larvae was the most susceptible to acetamiprid, and the 4th instar larvae was the most tolerant to acetamiprid, the LC 50 values were 0.020 mg/L and 0.296 mg/L at 72 h after treatment, respectively. Sublethal concentrations of acetamiprid could delay the development of larvae and decrease the weight of pupa. We suggested that acetamiprid is a safe and effective substitute for the using larvicides of mosquitoes.
