O inseticida thiodan® sobre o desenvolvimento folicular de lambaris

Abstract

Thiodan® is an organochlorine based in endosulfan which can cause morphological changes in fish tissues exposed to it depending on the concentration and exposure time. This study aimed to determine the LC50-96h of Thiodan® (350g L-1 endosulfan) for lambaris females of Astyanax bimaculatus in a reproduction period and analyze the morphology of follicular development in different experiments. Four experiments were performed: without adaptation and no feeding, feeding without adaptation, with adaptation and without feeding, with adaptation and feeding. The LC50-96h determined was 13.6µg L-1, with a confidence interval from 10.1 to 18.4µg L-1 (P0.05). The lambaris were exposed to Thiodan® for 96 hours in three sub-lethal concentrations of 1.15, 2.3 and 5.6µg L-1 and without pesticides control group. Morphologically, it was noted that the action of Thiodan® in sublethal concentrations did not alter the morphology of follicular development. However, the follicular diameter in secondary follicles in the experiment with adaptation and feeding exposed to Thiodan® was higher relative to the control group (P0.05). These data suggest that reproduction may be affected by chemical and can cause impairment in the follicular development.