Histological alteration in the ultimobranchial gland of catfish Heteropneustes fossilis in response to microcystin– LR treatment

Abstract

Freshwater catfish Heteropneustes fossilis (both sexes, average body weight 25-35g) were collected and acclimatized. The experimental fish were intraperitoneally injected with Microcystin-LR (2.5 μg/25 g) at the initiation of the experiment. Fish were sacrificed after 1, 3, 5, 10 and 15 days. The ultimobranchial gland (UBG) of control H. fossilis exhibits no change throughout the experiment. In microcystin injected fish (group B), there is no significant change has been observed in the nuclear volume of ultimobranchial cells after day 1. The nuclear volume of ultimobranchial cells exhibits a progressive decrease from day 3 to day 10. However, on day 15, the nuclear volume of ultimobranchial cells of microcystin injected fish almost becomes normal. The degeneration of ultimobranchial cells are discerned in microcystin injected fish (group B) on day 10 and day 15. It can be concluded from the present study that microcystin- LR is effective in inducing histological changes in the ultimobranchial gland of fish and causing physiological disturbances.