三氯异氰尿酸对脊尾白虾幼体存活及发育的影响

Effects of trichloroisocyanuric acid on the survival and development of Exopalaemon carinicauda larvae

三氯异氰尿酸(Trichloroisocyanuric acid,TCCA)是水产养殖中常用的水质消毒剂,使用不当会给生产和环境带来危害。为指导脊尾白虾(Exopalaemon carinicauda)人工育苗过程中TCCA的安全用药,作者利用静水试验法研究了TCCA对脊尾白虾幼体的急性毒性及对幼体发育的影响。实验设7个浓度梯度组(1.0、1.5、2.0、2.5、3.0、3.5、4.0 mg/L)和1个空白对照组,每组3个平行。急性毒性实验持续96 h后结束,用正常育苗海水代替TCCA溶液,正常管理直到幼体全部变态为仔虾,评估短时间的TCCA处理对脊尾白虾幼体发育的影响。结果表明,TCCA对脊尾白虾幼体在24、48、72和96 h的半致死浓度分别为3.81、3.03、2.71和2.47 mg/L,其安全浓度为0.25 mg/L;随着TCCA浓度的升高,脊尾白虾幼体变态存活率显著降低(P<0.05),但能成功变态为仔虾个体的变态持续时间及仔虾体长与对照组无明显差异(P>0.05)。本实验结果可以为脊尾白虾人工育苗安全用药提供参考和依据。

Trichloroisocyanuric acid （TCCA） is a common disinfectant used in aquaculture, however, improper use of TCCA will bring hazard both to aquaculture and environment. In order to learn the effect of TCCA on aquacul-ture, a static bioassay test was conducted to investigate the acute toxicity of TCCA and its effects on the larvae de-velopment of Exopalaemon carinicauda. New-hatched larvae of E. carinicauda were exposed to eight concentra-tions of TCCA （0, 1.0, 1.5, 2.0, 2.5, 3.0, 3.5 and 4.0 mg/L for 96 h, and three replicates was set under each concen-tration level. After each exposure of TCCA, the survived individuals were reared under normal conditions till de-veloped to the postlarvae stage. The metamorphosis survival, metamorphosis duration and body length of the post-larvae were compared to evaluate the possible chronic toxicity of TCCA to E. carinicauda larvae. The results showed that the 24, 48, 72 and 96 h LC50 are 3.81, 3.03, 2.71 and 2.47 mg/L, respectively. The safe concentration （SC） of TCCA to E. carinicauda larvae is 0.25 mg/L. The metamorphosis survival decreased significantly （P〈0.05） with the increases of TCCA concentration, while there was no significant difference in metamorphosis duration and body length of the postlarvae for the survived individuals among different TCCA concentrations （P〉0.05）. The re-sults in the present study provide important references for safe medication in nursery of E. carinicauda.