Thiodan(r) 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(r) (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 (P<0.05). The lambaris were exposed to Thiodan(r) 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(r) in sub-lethal 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(r) was higher relative to the control group (P<0.05). These data suggest that reproduction may be affected by chemical and can cause impairment in the follicular development
Astyanax bimaculatus; environment; ovary; follicles
