Abstract: Benzisothiazoline（BIT）,as one of the most efficient preservatives,is widely used in industry. It is broadly distributed in environmental water condition,and has recently been regarded as a potential threat to aquatic organisms,especially to the fish. Zebrafish was used as a test organism,and the developmental toxicity and oxidative damage of BIT to zebrafish embryos were investigated by 96 h acute exposure test,oxidative stress test and related gene expression analysis. The results showed that BIT severely inhibited the hatching rates of 51 hours post-fertilization embryos under BIT exposure,and resulted in their malformation. The 96 h half lethal concentration and 96 h half teratogenic concentration were 3.65 mg/L and 1.31 mg/L,respectively. The activities of stress-related oxidative enzymes（SOD,CAT,and GST）were affected at varied level,and the expressions of related genes（Mn-sod,cat,gstp-2,nqo-1,cox-1,and ucp-2）were interfered,indicating that the organism was severely in oxidative damage. Meanwhile,the expression patterns of apoptosis-related genes（bcl-2 and bax）also changed toward the direction of apoptosis promotion,indicating that oxidative damage led to apoptosis. In summary,BIT has high developmental toxicity to zebrafish embryos at early stage and induces oxidative damages to zebrafish embryos,and leads to the death of embryo at the end. This study provides a scientific basis for environmental risk management of BIT.

Key words: benzisothiazoline（BIT）, zebrafish embryo, acute toxicity, oxidative stress