Characteristics of a hybrid (F1 A. baerii x A. gueldenstaedtii) sperm production at different ages when grown on an industrial cage farm

Stanimir Bonev, Boyko Georgiev, Lyudmila Nikolova, Paulina Taushanova

Abstract: The study was performed with male hybrid individuals (F1 Acipenser baerii x Acipenser gueldenstaedtii) aged seven, eight and nine years, grown on a cage farm located in a warm water dam. No significant differences were found between age groups in ejaculate volume and sperm concentration. Motility analysis showed that sperm in the oldest individuals had the highest values (p < 0.05) of VCL, VSL, VAP, ALH and BCF, while the differences in indicators were not significant between the hybrids at 7- and 8 years of age. The relative proportion of rapid sperm in the hybrid semen of varies from 0 to 96.90%; of medium sperm from 1.0 to 46.74%; slow from 0.28 to 75.30%; static from 0 to 84%. The relative share of spermatozoa with non progressive motility varies from 15.30 to 89.70%, and those with progressive motility – from 0.10 to 29.85%. The oldest fish had significantly (p < 0.05) the best characteristics of sperm motility – the highest share of rapid and those with progressive motility; lowest of the slow and static. Age affects the enzymatic activity of sperm. In 7- and 9-year-old fish, a significant difference was found in AP, GGT, CK in water extract, and in LDH in triton extract. The water extract in 9-year-olds has higher levels of AP (7 times; p < 0.05) and GGT (3.2 times; p <0.05), while in 7-year-olds fish the values of CK are higher (2.3 times; p < 0.05). In LDH, the difference (1.5 times) is also in favor of 7-year-old individuals, but it is not significant. In the triton extract only AP levels are higher (over 30%) in 9-year-old fish, but the difference is not significant. For the other indicators (GGT, CK and LDH) the difference is in favor of the younger fish, respectively 4.6 %, 22.1 % and 2.9 times, and for the latter it is statistically significant (p < 0.05).

Keywords: sturgeon semen, enzyme activity, spermatozoa velocity.

Date published: 2022-11-02