Motility, vigor and pathologies in fresh and cryopreserved semen of Piaractus mesopotamicus.

Abstract

Spermatozoa morphological alterations of eleven pacus (Piaractus mesopotamicus) were evaluated before and after frozen-thawed processing. The semen cryopreservation caused a decrease (P 0.05) before and after cryopreservation. The progressive motility and the spermatic vigor were reduced in frozen-thawed semen in 66.45 and 34.2%, respectively (P<0.05). Moreover, bent tail abnormality and broken tail pathology were increased in 65.00 and 41.25% (P<0.05) after frozen thawed. Also, macrocephaly and distal cytoplasmatic drop were observed in the semen only after freezing, while short tail spermatozoa were observed only in fresh semen. However, a higher occurrence of loose tail was observed in fresh semen.