1Japan Frozen Foods Inspection Corporation, Tokyo 105-0012, 2National Research Institute of Fisheries and Environment of Inland Sea, Hiroshima 739-0452, Japan
Effects of moulting and experimental conditions such as water temperature and salinity on acute toxicity of hazardous chemicals to shrimps were investigated in order to establish a toxicity test using Penaeus japonicus and Heptacarpus futilirostris as test organisms. 96h LC50 of tributyltin chloride (TBTCl), triphenyltin chloride (TPTCl), γ-hexachlorocyclohexane (γ-HCH), fenitorthion (MEP), carbaryl (NAC) and pentachlorophenol (PCP) to P. japonicus was 3.4-48μg/L, 23-260μg/L, 4.1μg/L, 0.49μg/L, 10μg/L and 1100-24000μg/L, respectively. The 96h LC50 of these hazardous chemicals to H. futilirostris was 3.6μg/L for TBTCl, 3.8-4.2μg/L for TPTCl, 1.7-2.1μg/L for γ-HCH, 0.96-1.1μg/L for MEP, 6.8-7.6μg/L for NAC, 140μg/L for PCP and 17000μg/L for chromium (Cr(VI)). TPTCl and PCP showed higher acute toxicity on H. futilirostris, however, acute toxicities of tested chemicals other than TPTCl and PCP were almost the same for the two shrimp species. The acute toxicities of TBTCl, TPTCl and PCP to P. japonicus increased ten times after it moulted in the experimental period. On the other hand, acute toxicity to H. futilirostris was not affected by moulting. The acute toxicity was not affected by temperature and salinity of the rearing seawater.