The Separate and Combined Effects of Copper and Cadmium on the Survivorship of Penaeid Shrimps

Abstract

Critical survival rate for all larval stages of penaeid shrimp was determined using static bioassay with copper, cadmium and their I: I mixture. The lethal concentration (24 h LC50) was 200 mg/l of Cu. 250 mg/l of Cd and 300 J.LS'L of mixture in average for all larval stages along with slight variation at every stage (Nauplii- Myses III) in Penaoul monodon LC50 was 400 mg/l. In Penaeul -nicillatul LC,o the values were found to be 200 mg/L of Cu, 230 of Cd and 250 mg/L for mixture in Nauplii to Myses however for postlarvae the LC,o was within the same as in Penaeul monodon. The estimation of survival rate within 24·48 h under lethal and acceptable concentration of copper and cadmium showed culturing farmers at most productive and safe condition of their ponds.