Effect of cryoprotectants on the semen quality of Nile Tilapia Oreochromis niloticus

Samples of Nile Tilapia (Oreochromis niloticus) semen were collected with the aim of evaluating the quality of cryopreserved semen using methanol and dimethylacetamide (DMA) as cryoprotectant agents at the concentrations of 7.5% and 10% each. The diluent (base) used in each cryoprotectant consisted of Beltsville Thawing Solution (BTS). An examination of the motility factors, robustness, and duration of motility was conducted using sodium carbonate (at 1% solution) for semen activation. The results were higher in methanol regarding robustness, and 7.5% methanol in relation to motility rate and duration of motility. The cryopreservation process increased the number of morphological pathologies, primarily fractured tail, isolated head and folded tail, except for treatment with DMA 7.5%.