Cryopreservation of Sex Reversed Gynogenetic Female Sperm in Hirame

The pooled stripped semen from sex reversed gynogenetic female hirame Paralichthys olivaceus of 3+ age was cryopreserved for 6 months in the liquid nitrogen. After the thawing the fertility of sperm was tested in two densities of sperm by inseminating eggs removed from a normal female hirame. Also, fresh semen was stripped from normal males for use as controls. The mean normal hatching rate to number of examined eggs was 51.2% in the high density group of fresh sperm. The mean rates in the high density group of cryopreserved sperm, in the low density group of fresh sperm, and in the low density group of cryopreserved sperm were the second (44.6%), third (42.6%), and fourth highest (35.5%), respectively. However, the differences between each group were not significant (p>0.05). Thus, cryopreserved sperm of sex reversed gynogenetic females hirame are comparable in efficiency with fresh sperm.