Study of ovarian fluid biochemical parameters and its influence on spermatozoa motility of the Ship (Acipenser nudiventris Lovetzky, 1828) in the south-eastern Caspian Sea

Biochemical aspects of ovarian fluid were investigated in 10 specimens of the Ship (Acipenser nudiventris) by assessment of ionic organic composition and their relationships with osmolality. Also spermatozoa motility of the ship sturgeon was investigated in different percentage (5, 10, 25, 50 and 100%) of ovarian fluid (pooled 6 samples). Ovarian fluid contained 104.78±32.12mmol/1 Nat, 3.43±1.08mmol/ 1(7, 3.26±0.87mg/d1 Ca2+, 7.32±1.06rnEcil1 Mg^2+, 0.606±0.207mg/l protein, 24.88±13.02mg/l cholesterol and 60.35±14.49m/1 glucose. The pH of ovarian fluid ranged from 7.29 to 8.10 and osmolality ranged from 185 to 212msmol/Kg. There was also significant positive correlation between Nat concentration and osmolality (r = 0.835, P<0.01). When ship sturgeon semen diluted with 50 and 100% ovarian fluid, the spermatozoa remained immotile. The total duration of motility and percentage of motile spermatozoa was greatly reduced when semen was diluted in ovarian fluid higher than 5%. We found that the spermatozoa of ship sturgeon are immotile in the ovarian fluid because of ovarian fluid composition such as high concentration of K and osmotic pressure.