Effects of deltamethrin on serum calcium and corpuscles of Stannius of freshwater catfish, Heteropneustes fossilis

Abstract

Catfish, Heteropneustes fossilis, were subjected to deltamethrin for short-term (96 h; 1.49 μg L−1) and long-term (28 days; 0.37 μg L−1) durations. The effects of deltamethrin exposure were evaluated on the corpuscles of Stannius (CS) of the fish, as it has been reported recently that stanniocalcin homologs are present in fish as well as in tetrapods, including human beings. Moreover, in addition to their role in mineral homeostasis, stanniocalcin proteins also play a significant role in metabolism, reproduction, and development. Serum calcium levels of deltamethrin-treated fish decreased from 48 to 96 h in the short-term, and from day 7 to day 28 in the long-term experiment. The aldehyde fuchsin-positive (AF-positive) cells of CS of deltamethrin-treated fish exhibited increased granules after 72 and 96 h. No change was noticed in the nuclear volume of AF-positive cells. The AF-negative cells of CS depicted an increased nuclear volume after 96 h of deltamethrin treatment. The AF-positive cells of CS of long-term deltamethrin-treated fish exhibited increased granulation after 21 and 28 days. The nuclear volume of these cells depicted a progressive decrease from 14 days until the end of the experiment. The nuclear volume of AF-negative cells exhibited an increase at 21 and 28 days.