Effect of cadmium and zinc in different salinity levels on survival and osmoregulation of white shrimp (<i>Litopenaeus vannamei</i>Boone)

Abstract

This study compared the acute toxicity of Cd and Zn on juvenile Litopenaeus vannamei when administered at different salinities. It also evaluated the effect of sublethal Cd and Zn concentrations on the osmoregulatory capacity (OC) of the juvenile shrimp. Tolerance to Cd and Zn increased progressively with increasing salinity. Cadmium was more toxic than zinc. The 96 h LC50's of cadmium to juvenile L. vannamei were 450, 690, and 1020 µg Cd L−1 at 5, 15, and 27 ppt salinity, respectively. The 96 h LC50's of zinc were 3780, 5520, and 8910 µg Zn L−1 at 5, 15, and 27 ppt, respectively. Exposure to sublethal concentration of Cd and Zn reduced the hyper-OC of exposed shrimp at 5 and 15 ppt salinity, and increased the hypo-OC of exposed animals at 27 ppt salinity.