This study aimed to evaluate the influence of cryoprotectants, thawing times and temperatures on pacu (Piaractus mesopotamicus) sperm abnormalities. Semen samples from four pacu were collected and diluted in 2 solutions, cryoprotectant dimethylsulfoxide (DMSO) 10% and methanol 10%. After thawing, semen was collected for morphological analysis, evaluating primary and secondary abnormalities. There was no interaction (P>0.05) of secondary abnormalities, abnormalities in total and normal sperm in the different treatments. The primary abnormalities showed interaction between temperature and thawing time, where the higher temperature was associated with the shortest time (60°C for 8s) or the lowest temperature associated with longer thawing (40°C for 12s) provided under (P<0.05) percentages of spermatozoa with primary abnormalities. In the process of semen cryopreservation of P. mesopotamicus using the cryoprotectants DMSO and methanol, it is recommended that thawing be performed at 40° C for 12 seconds or 60°C for 8 seconds.
fish; cryopreservation; DMSO; methanol; semen
