Interaction of potash and decis in the ecophysiology of a freshwater fish Oreochromis mossambicus.

ABSTRACT

Interaction of potash and decis in the ecophysiology of a freshwater fish, Oreochromis mossambicus, was studied. It was found that 300, 550 and 700 mgL(-1) of potash were sublethal (LC(0)), median lethal (LC(50)), and toxic (LC(100)) to O. mossambicus for 96h exposure, respectively. For decis, 96 h LC(100,) LC(50), and LC(0) was 0.4, 0.25, and 0.1 mgL(-1), respectively. Sublethal concentrations of potash and decis were exposed to fishes individually and in combination for 28 days. The results revealed that the combined effect of these chemicals was more highly toxic to food intake, growth, and conversion efficiencies than the individual chemicals. The marker enzymes (acid phosphatase, alkaline phosphatase, aspartate transaminase, alanine transaminase) were also analyzed in blood, liver and muscle. The enzyme activities were decreased in liver and muscle. On the other hand, serum exhibited increased activities of marker enzymes. The results were tested statistically and interpreted accordingly.