Some properties of bream Abramis brama L. sperm and its cryopreservation

Concentration and motility of spermatozoa, total protein content and its electrophoretic profile, glucose content, activity of aspartate aminotransferase (AspAT) and acid phosphatase (AcP) were assessed in 18 samples of semen from common bream Abramis brama L. males, which were hormonally stimulated to spermiation. Also, milt pooled from four donors was cryopreserved as pellets in vapours of liquid nitrogen (?80 °C) using four extenders (each with or without the addition of hen egg yolk). Mean spermatozoa concentration was 11.68 × 10⁹ mL^?1, and mean spermatozoa motility was about 60%. Protein content in seminal plasma was 2.08 mg mL^?1; both PAGE and SDS–PAGE showed considerable heterogeneity of protein fractions. Mean glucose content was over 11 mg%. AspAT and AcP activities were detected in both seminal plasma and spermatozoa extracts. As calculated to 1 × 10⁹ spermatozoa, AcP and AspAT activities were almost sixfold and 46-fold higher in spermatozoa than in seminal plasma respectively. In the best variant, cryopreservation attempts resulted in 66.6% of eyed embryos (compared with control fertilization) obtained after fertilization of eggs with cryopreserved semen.