Lethal Effects of Cadmium in Tropical Fishes

Abstract

The lethal concentration (LC₅₀) values of cadmium (Cd²⁺) for three species of the tropical fishes Tilapia mossambica, Poecilia vivipara, and Cyprinodon dearborni were determined by the static bioassays. The fishes were collected from the Laguna Los Patos, Cumana, Sucre State, Venezuela, and were acclimated for three weeks under laboratory conditions prior to bioassays. Acclimation temperature and salinity were 25°C and 15‰, respectively.
The 216-h LC₅₀ values (mg/l) estimated by the graphical interpolation of probability-logarithm transformation were found 48 for Tilapia mossambica, 20 for Poecilia vivipara, and 10 for Cyprinodon dearborni. This indicates that the order of sensitivities to cadmium is: C. dearborni>P. vivipara>T. mossambica.