PRELIMINARY RESEARCH ON CRYOPRESERVATION OF SPERM IN THE SILURUS GLANIS SPECIES

The main objective of the research was to optimize cryopreservation techniques for sperm of European catfish (Silurusglanis), a species of major economic importance in aquaculture. The study tested different cryoprotectants (dimethyl sulfoxide – Me₂SO,methanol and Me₂SO–propanediol combinations), as well as the influence of equilibration times and freezing volumes on the quality of the semen. The sperm was collected from hormonally stimulated breeders, and after thawing, essential parameterswere evaluated: sperm motility, cell viability and hatching rate. The results showed that Me₂SO (8–12%) and the combination of Me₂SO + propanediol ensured the best performances, with high hatching rates (82–86%), comparable to the fresh control (87–88%). Methanol, on the other hand, led to a significant reduction in incubation success (53–63%). A strong correlation was found between post-thaw motility and hatching rate (r = 0.76; P < 0.001), while isolated cell viability was not a relevant indicator offertilization capacity. These results confirm the efficiency of Me₂SO cryopreservation and provide a solid basis for the application of the method in controlled breeding and genetic conservation programs for European catfish.