The analyses of density, velocity, and osmolality
were performed immediately after semen collection
according to the methodology used for carp by Warnecke
and Pluta [31]. Sperm concentration (109 cells/mL) was
measured according to the methods described [32]. Semen
was diluted by a factor of 1000 in a physiologically
saline solution, a droplet was placed on a Burker cell hemocytometer (depth 0.1 mm) and left for a few seconds
for sedimentation, and then, 16 cells of the hemocytometer
were counted at 200 magnification. For the osmolality
assays, a digital freezing osmometer at 45 AV
(Roebling) was used