Abstract The effects of three commercial hormonal preparations: carp pituitary extract (CPE), Ovopel, and Ovaprim, on quantitative and qualitative parameters of milt from the crucian carp, Carassius carassius (L.), during the spawning season were examined. Males in the control group were injected with 0.9% NaCl. The total volume of milt (ml), total sperm count (× 10 9 ), and concentration of sperm in milt (× 10 9 /ml) were analyzed. Percent motile sperm, percent sperm with progressive movement, curvilinear velocity (µm/s), straight-linear velocity (µm/s), movement linearity (%), wobbling index (%), amplitude of lateral head displacement (µm), and beat cross frequency (Hz) were determined with a computer-assisted sperm analysis (CASA) system. The volume of milt, sperm count, and lateral head displacement were significantly greater in males receiving the Ovaprim treatment than in males stimulated by CPE, Ovopel, or the control but there were no significant differences in any other characteristic. The IJA appears exclusively as a peer-reviewed on-line open-access journal at http://www.siamb.org.il. To read papers free of charge, please register online at registration form. Sale of IJA papers is strictly forbidden. Sale of IJA papers is strictly forbidden. 2 Cejko et al
