Reproductive Biomarkers of Endocrine Disruption in Adult Male Clarias Gariepinus Exposed to Sub-Lethal Carbendazim

Abstract

This study investigated the morphophysiological effects of Carbendazim in the adult male African catfish (Clarias gariepinus). After exposure to a pre-determined sub-lethal concentration (1.4 mg/L) of carbendazim for seven and fourteen days, plasma testosterone and 11- ketotestosterone, the gonadosomatic indices were determined. Histomorphometry and histochemistry of the testes was studied using light microscopy after staining with Hematoxylin-Eosin, Masson’s Trichome and Periodic Acid Schiff. Testicular tissues harvested at day 14 were fixed in  glutaraldehyde and processed for transmission electron microscopy according to standard procedures. All the treated groups showed significant phase dependent alterations, day 14 being more  pronounced. The gonadosomatic indices were  decreased. Significant decreases, relative to corresponding controls at day 14, were observed in testosterone and 11-ketotestosterone levels. Histological and ultrastructural studies revealed germinal and  Sertoli cell degeneration and necrosis, displacement of Sertoli cysts, capillary endothelial wall necrosis and basement  membrane disruption in the testis of the treated groups. There were significant  reductions in testicular germinal depth and interstitial width in 14-day treated  groups compared to its corresponding control. Carbendazim, at sub-lethal dose, induced histological and  ultrastructural changes in the testes of the male African catfish. It also led to altered gonadosomatic index; reduced levels of plasma  testosterone and 11-ketotestosterone levels.

Keywords: Carbendazim, Carbendazim, Clarias gariepinus, ultrastructure,  Histomorphology