Effect of Different Activation Solutions and Protein Concentrations on Ide (Leuciscus idus) Sperm Motility Analysis with a CASA System

SIMPLE SUMMARY: Computer-assisted Sperm Analysis (CASA) systems are currently used to determine the sperm motility of various fish species. Our previous research indicated that one of the problems with CASA analysis is that sperm adheres to glass slides, which was noted in common carp (Cyprinus carpio). Supplementing activation solutions (AS) with proteins such as bovine serum albumin (BSA) or casein eliminates this problem and improves sperm motility. However, there is a lack of information regarding the minimal effective concentration of these proteins for ide (Leuciscus idus) sperm motility measurements. The present study is the first to compare four AS-Woynarovich, Lahnsteiner, Kucharczyk, and Perchec–for ide sperm motility activation. Woynarovich and Perchec solutions were selected and supplemented with different concentrations of BSA (0.25, 0.5, 1.0, and 2.0%) and casein (0.25, 0.5, 1.0, and 2.0%) for further motility measurements. Compared to pure Woynarovich and Perchec solutions (without proteins), the addition of the minimum concentration of BSA and casein (i.e., 0.25%) significantly improved CASA parameters of ide sperm. This dose was also sufficient for preventing sperm from adhering to glass slides. The different BSA (0.5–1.0%) and casein (1.0–2.0%) concentrations in Woynarovich and Perchec solutions affected CASA parameters differently. ABSTRACT: The purpose of this study was to compare four activation solutions (AS)—Woynarovich, Lahnsteiner, Kucharczyk, and Perchec—with the addition of 0.5% bovine serum albumin (BSA) for ide (Leuciscus idus) sperm activation and analysis with a CASA system. It was found that ide sperm can be activated using each AS within a pH range of 7.4–9.0 and an osmolality range of 160–200 mOsm kg(−1). The effect of Woynarovich and Perchec solutions supplemented with BSA and casein at concentrations of 0.25, 0.5, 1.0, and 2.0% were also analyzed during the experiment. These two AS without protein supplementation (pure solutions) were the controls. Woynarovich and Perchec solutions supplemented with the minimum BSA concentration (i.e., 0.25%) significantly improved sperm motility (89.05% and 86.63%, respectively) compared to the controls (20.39 and 28.48%, respectively). Similar increases were also noted in progressively motile sperm (PRG, %), the curvilinear velocity of sperm (VCL, µm s(−1)), and the amplitude of lateral head displacement (ALH, µm). A similar trend in CASA parameters was also noted when casein was added to Woynarovich and Perchec solutions at a concentration of 0.25%. We concluded that 0.25% doses of each of the proteins were sufficient to prevent sperm adhesion to glass slides, and they can be used in research on ide sperm motility measurements.