Effect of anti-adhesive supplement doses on sperm motility characteristics in the European whitefish (Coregonus lavaretus).

Sperm adhering to glass slides is one of the main problems during fish sperm motility analyses with CASA systems. To mitigate this, albumin is the supplement added most frequently to activating solutions. However, there is no data on the use of supplements other than albumin (in various concentrations) in analyses of European whitefish (Coregonus lavaretus) sperm motility. This issue was investigated in the presented research using three anti-adhesive supplements (albumin, casein, Pluronic F-127) that were added to Billard solution (BS: 20 mM Tris, 1 mM CaCl, 154 mM NaCl, 30 mM glycine at pH 9.0) at different concentrations (0.0; 0.1; 0.2; 0.5; 1.0; 2.0%). It was noted that the addition of the lowest concentration (0.1%) of albumin, casein, or the pluronic to BS had a significant effect on the motility and kinetic parameters of whitefish sperm compared to pure BS. BS supplemented with 0.2-0.5% albumin was the most appropriate variant used for whitefish sperm motility activation in the present experiment. BS supplemented with the pluronic at 1.0-2.0% concentrations resulted in significantly higher values of almost all CASA parameters compared to casein at the same concentrations. Moreover, CASA parameters determined in this variant of the pluronic (1.0-2.0%) were similar to those when BS was supplemented with the same albumin concentrations. This indicated that instead of albumin, the pluronic at higher concentrations in BS might be used to analyze whitefish sperm motility.