Acute toxicity test of four disinfectants to juvenile Pinctada maxima

The acute toxicity of glutaraldehyde，dibromohydantoin，methionine iodine and calcium hypochlorite to juvenile Pinctada maxima was studied. The results showed that the order of toxicity was calcium hypochlorite> dibromohydantoin> methionine iodine> glutaraldehyde，and the median lethal concentrations（ LC50） of above disinfectants were 13.05 mg/L，27.49 mg/L，53.20 mg/L and 67.36 mg/L respectively in 24h，and the LC50 were 10.15 mg/L，9.35 mg/L，29.27 mg/L and 35.58 mg/L respectively in 48h；and their SC（ safe concentration） were 1.86 mg/L，0.32 mg/L，2.66 mg/L and 7.52 mg/L respectively. We can use glutaraldehyde to disinfect P. maxima under safe concentration，but should not use calcium hypochlorite，and can use dibromohydantoin and methionine iodine carefully.