The influence of zinc on sperm motility of common carp - a computer assisted studies

Abstract

The influence of zinc on common carp sperm motility was investigated using a computer assisted sperm analysis (CASA) as well as subjective microscopic measurements of time of motility. The analysis by CASA method consisted of 3 parameters - curvilinear velocity (VCL), average path velocity (VAP) and straight line velocity (VSL), The following zinc concentrations were used: 10, 50, 100, 200, 500, 1000 and 2000 ppm. Both, CASA and subjective microscopic observations of sperm motility showed that zinc decreased the motility of sperm, having lethal effects at concentrations of 500 ppm (as analysed by computer assisted methods) or 200 ppm (as evaluated using microscopic observations of time of motility). Moreover, the computer-assisted analysis demonstrated that zinc had the strongest inhibitory influence on VSL, suggesting the possibility of its negative impact on the fertilisation rate. CASA method seems to be more reliable than classical microscopic observation of sperm activity.