Effects of Pyrethroid Pesticide Cypermethrin on the Gonad and Hemato-biochemical Parameters of Female Gangetic Mystus (Mystus cavasius)

A 90-day experiment was conducted to study the effect of sub-lethal concentration of cypermethrin exposure on mortality, Gonadosomatic index (GSI), ovarian cell development and hemato-biochemical parameters of Gangetic mystus (Mystus cavasius). According to previous findings of LC50 value (30µg/L) of cypermethrin the experiment was carried out using four sub-lethal concentrations as treatment (0.0, 4.0, 8.0, and 16.0µg/L). The whole water was exchanged in every 4th day and pesticide was mixed accordingly. For collection of gonad and blood, fish were sampled at 30, 60 and 90 days after starting of pesticide exposure. There were no significant changes on GSI. Several histopathological changes were observed in ovary. Wrinkle oocyte, cytoplasmic clumping, atretic follicle, degenerated granulose layer, degenerated oocyte wall, increased inter follicular space, adhesion, cyst, necrosis were found in the ovary of M. cavasius with increasing cypermethrin concentration and exposure time. Blood glucose level and WBCs were significantly increased whereas blood hemoglobin and RBCs were significantly decreased in exposure groups compared to control groups over the three sampling days. The current findings revealed that cypermethrin had negative impact on the hemato-biochemical parameters and female gonad of M. cavasius. So the use of cypermethrin in agriculture should be done with a great caution.