Computer Assisted Sperm Analysis (CASA) was used to evaluate and compare the sperm motility parameters of Siberian sturgeon, Acipenser baerii Brandt (n=15), and sterlet, Acipenser ruthenus L. (n=15). Analysis indicated a higher percentage of motile sperm (MOT) in the sterlet semen (44.8%) than in that of the Siberian sturgeon (41.3%). The sperm of the two species studied were similar with regard to velocity, and similarities were also noted with regard to average path velocity VAP (97.6 and 102.4 μm s-1), curvilinear velocity VCL (121.9 and 119.9 μm s-1), and straight line velocity VSL (82.5 and 86.8 μm s-1). Using the CASA system permitted making precise evaluations of the sperm motility of the two fish species studied, and thus also permitted determining the potential suitability of the semen for use in sturgeon reproduction.
