The effects of Diazinon (organophosphate pesticide) on motility indices and morphological parameters of Caspian Lamprey (Caspiomyzon wagneri) sperm

The Caspian Lamprey (Caspiomyzon wagneri) is native to the Caspian Sea that migrates into its rivers for spawning، while is encountered with many threats including the organophosphate pesticides pollution. This study conducted to investigate the effects of an organophosphate pesticide i. e. Diazinon، on motility indicators and morphology of sperm in Caspian Lamprey. Hence، sperm were exposed to Diazinon in concentrations of 0. 01، 0. 05، 0. 1، 0. 5، 1 and 5mg/l until the end of its motility. The results showed that increasing concentrations of Diazinon significantly reduce sperm motility (P<0. 05). Increasing length، width and area of head، destruction and amputation of flagellum were significantly raised among sperm in three minutes of Diazinon exposure (P<0. 05). The results also displayed that percentage of damaged sperm significantly increased according to Diazinon concentration (P<0. 05) with a maximum effect at concentration of 5m/l in which the amputation of flagellum، twisting and shortening of flagellum، head deformity and destruction of sperm was recorded 4. 4%، 26. 6%، 15. 3% and 31% respectively. Finally، this study can suggest that Diazinon effects on reproduction process of Caspian Lamprey decreasing sperm quality indicators i. e. motility and its morphological parameters. This can probably reduce the rate of fertilization in this species threatening its survival.