Inhibiting the influence of ovarian fluid on spermatozoa activation and spermatozoa kinetic characteristics in the common barbel Barbus barbus.

As a result of evolution, various finfish species have developed different breeding strategies. However, there are some similarities, and one of them is the positive effect of ovarian fluid on spermatozoa. The opposite of this phenomenon was found in the common barbel (Barbus barbus). The present study analyzed the effect of ovarian fluid (OF), distilled water (DW) and Woynarovich solution (WS) on the motility, longevity and kinetics of barbel spermatozoa. These spermatozoa parameters were also evaluated with various dilutions of ovarian fluid (OF) in relation to distilled water [0:4 (Group OF 0%), 1:3 (Group OF 25%), 1:1 (Group OF 50%), 3:1 (Group OF 75%), 4:0 (Group OF 100%)] and spermatozoa reactivation after a 30 s (Group OFR 100%) treatment in ovarian fluid. The motility analysis was carried out using computer-assisted semen analysis (CASA). The negative interaction of ovarian fluid with spermatozoa motility in the same fish species was recorded for the first time. In pure ovarian fluid, the average spermatozoa motility (MOT) decreased significantly (1.40 ± 0.94%). The negative effect of ovarian fluid-to-spermatozoa motility was reversible, and after a 30 s treatment in ovarian fluid and later dilution with water, spermatozoa motility was reactivated (from 2.25 ± 0.53% vs 69.78 ± 6.02%). The use of Woynarovich solution as an activator of spermatozoa movement had a positive effect (P < 0.05) on spermatozoa movement longevity (motility up to 90 s) and the percentage of motile spermatozoa compared to distilled water (up to 45 s) and ovarian fluid (P < 0.05).