Effect of different level of Zinc on the morphological structure of sperm in Caspiomyzon wagneri

Abstract

The present study was performed to investigate the effect of zinc on the sperm morphological indices of Caspimyzon wagneri. For this purpose, sperm were exposed to 0.01, 0.1, 1, 10, 100 and 1000 mg L-1 Zn three minutes, three and 36 hours at in vitro condition. Based on the results, destruction of sperm’s structure exposed to Zn showed an increase in the length, width and surface of sperm’s head, flagella degradation and somewhat flagella breakage. These increased damaging effects were more visible by enhancing the concentration of Zn or the exposure time became. When exposure time to Zn exceeded the certain period of time (3 min) in order to simulation of Zn accumulation in testis tissue, the damage effects of sperm structure observed including head length reduction and head width increase (reduction of sperm’s head surface), complete cutting of flagella at all samples and deformation of the sperm’s head from oval to circular. These changes became visible during 36 hours of exposure to Zn. Therefore, the presences of pollutants including Zn in natural reproduction grounds of this species can cause adverse effects on sperm function, fertilization and hatching rate by damaging the sperm morphology, and consequently threat the generation survival of this rare species.

Keywords

• caspian lamprey
• morphological indices
• sperm
• zinc