The article studies the possibility to use glycerol as cryoprotectant, instead of dimethylsulfoxide for cryopreservation of sperm of inconnu ( Stenodus leucichthys Gueldenstaedtii, 1772). Investigations were carried out from 2015 to 2016 in the laboratory of the Southern Scientific Center, Russian Academy of Sciences, on the basis of the Astrakhan State Technical University. The material collected on the Alexander sturgeon hatcheries (the Astrakhan region) in the spawning period. Native sperm of 6 male inconnu species was used as a control means. The semen quality was determined in terms of moving activity (life time) of sperm after its activation by water. As the cryoprotectant there were used: base solution - 80%, sucrose - 1.71 g/l, mannite - 0.98 g/l, yolk - 10%, dimethylsulfoxide - 10% and base solution - 87%, sucrose - 1.71% g/l, mannite - 0.98 g/l, yolk - 10%, glycerol - 3 variants: 3; 5 and 10%. In order to provide the most complete penetration of cryoprotectants into the cells there were used electrostimulation of cell membranes. Equilibration time was 5 and 15 minutes. Thawing semen was performed in a water bath at a temperature of 38-40°C. For removing protectors from cells there was chosen a saline solution (0.7% NaCl) as isotonic solution. In tests using dimethylsulfoxide life activity of sex cells was 2 times lower than in tests with glycerol: 78 and 186.2 s at the end of equilibration and 52.3 and 128.9 s after thawing. Sperm showed maximum activity under 5% glycerol concentration during equilibration - 15 min. Concentration of 3% was insufficient, concentration of 10% was excessive, as it suppressed activity of sperm. Egg yolk which coagulated together with glycerol, making difficulty for observing, had to be excluded from the composition of cryoprotectant.
Histochemical Observations on the Interrenal Gland and Liver of European Spotted Dogfish