Toxicity Of Cadmium, P-Chloroaniline And Four Common Aquacultural Drugs On Gobiocypris Rarus

Gobiocypris rarus is an endemic cyprinid in China. As one of the recommended test organisms in the Guidelines for the Testing of Chemicals, G. rarus is being widely used in studies of ecotoxicology and other research fields. This survey was carried out to investigate the acute toxicity, embryo-larva and the 7-day subchronic toxicity of p-Chloroaniline and Cadmium and acute toxicity of four common aquacultural chemicals on G. rarus. The results are as follows:1. The 96 h LC50 were 7.53μg/L,25.69μg/L,10.27μg/L and 525μg/L for ivermectin solution, phoxim,cypermethrin and purified malathion solution, respectively. The safety concentrations of the 4 chemicals were 0.753μg/L,2.57μg/L,1.027μg/L and 52.5μg/L, respectively. Among these four chemicals, the toxicity of Ivermectin solution is the highest, followed by cypermethrin, then phoxim, and the toxicity of purified malathion solution is the lowest.2. The acute toxicity test showed that the 96 h LC50 and safety concentrations (SC) of p-chloroaniline on juvenile G. rarus were 35.5 mg/L and 3.5mg/L, respectively. The 7-day subchronic toxicity test showed that as the concentration of the p-chloroaniline increase, the survival rate decrease, abnormality rate increase, and the growth rate slow down. The embryo-yolk sac stage was more sensitive than newly hatched larvae. The no observed effect concentration (NOEC), the lowest observed effect concentration (LOEC) and the maximum acceptable toxicant concentration (MATC) for embryo-yolk sac stage were 2 mg/L,4 mg/L, and 2.83 mg/L, respectively. The NOEC, LOEC and MATC for newly hatched larvae were 4 mg/L,8 mg/L, and 5.66 mg/L, respectively.3. The acute toxicity test showed that the 96 h LC50 and SC of cadmium for juvenile G. rarus were 12.24 mg/L and.1.22 mg/L, respectively. The 7-day subchronic toxicity test showed that there are obvious dose-effect relations between the concentration of cadmium and the hatching rate, abnormality rate, body length and body weight of G. raris. The NOEC, LOEC and MATC for embryo-yolk sac stage were 0.05 mg/L,0.1 mg/L, and 0.07 mg/L, respectively, when the hatching rate was used as biological indicator, and were 0.1 mg/L,0.2 mg/L and 0.14 mg/L, respectively, when body length and dry weight were used as biological indicators. The NOEC, LOEC and MATC for newly hatched larvae were 0.1 mg/L,0.2 mg/L and 0.14 mg/L, respectively, using body length and dry weight as biological indicators.