Growth of mozambique tilapia (Oreochromis mossambicus Peters) chronically exposed to cadmium, naphthalene, and DDVP

The chronic effects of cadmium, naphthalene, and DDVP on the growth of Mozambique tilapia ( Oreochromis mossambicus Peters) exposed to concentrations corresponding to 1/30 LC 50 for 24 h (cadmium and DDVP) and 1/15 LC 50 for 24 h (naphthalene) have been studied. The fish are kept in toxicant solutions for 60 days and then for 60 more days in clean water. It is found that the studied toxicants affect fish-growth indices to varying extents. Organic compounds have no significant effect on the linear and mass growth of tilapia. Cadmium most strongly suppresses tilapia growth, and the toxic effect of this metal is irreversible: all fish die after being transferred to clean water.