Pharmacological level of copper induces the immune and antioxidant mechanisms of Fenneropenaeus indicus conferring better protection against white spot syndrome virus infection

Abstract

Effect of ambient copper on the immune, antioxidant and lipid peroxidation parameters of Fenneropenaeus indicus and its susceptibility to white spot syndrome virus under heavy metal (Cu2+) exposure has been studied. Adult shrimps were acclimated to 25‰ salinity for a period of 7 days, and after 12 h of starvation, shrimps were dosed with 0.075, 0.150, 0.225 and 0.30 ppm Cu2+ by adding appropriate quantities of copper sulphate solution. After 14 days of metal exposure, the shrimps were challenged with white spot syndrome virus through oral administration and the immune and antioxidant parameters were analysed. Analysis of variance showed that there were significant differences (P < 0.05) in the immune and antioxidant parameters and lipid peroxidation product in different treatment groups of F. indicus compared to untreated group. The immune parameters and antioxidant enzymes have been significantly lowered (P < 0.05) in the haemolymph of shrimps dosed with higher concentrations of copper sulphate leading to lipid peroxidation and accumulation of malondialdehyde. However, there was less oxidative stress in shrimps exposed to 0.075 ppm Cu2+. The present study showed that high levels of Cu2+ enhanced the mortality of F. indicus with concomitant reduction in immune and antioxidant parameters. A concentration of 0.075 ppm Cu2+ in the rearing water was found to have beneficial effect in shrimps in terms of immunostimulation and higher survival against WSSV infection. This can be adopted as a pharmacological approach towards shrimp health management in culture systems.