Effects of two extenders on sperm motility indices during long term preservation of bester sturgeon (Huso huso♀×Acipenser ruthenus♂) semen

Sperm cryopreservation has been considered as one of the gamete management strategies for artificial reproduction in sturgeons. Bester is a promising fish in sturgeon aquaculture but sperm cryopreservation of this fish had not been studied before. In the present study, changes in motility indices of bester sturgeon spermatozoa were investigated after one year of cryopreservation with two different extenders. The mean percentage of motility, total duration and VSL of samples diluted with E1 extender were 47.57±4.7%, 96.77±6.61s and 125.39±40.81µms-1, respectively and reached to 33.71±5.36%, 102.5±5.24s and 60.84±24.55µms-1, respectively after one-year preservation. Diluted samples with E2 extender showed 41.47±3.06%, 102±9.01s and 110.26±31.19µms-1 for these parameters at sampling day and reduced to 28.51±4.55%, 82.67±10.11s and 52.77±27.6µms-1 after one-year preservation. Results of this study revealed that there are no significant differences among studied motility indices between two extenders (P>0.05). These findings could be regarded as basic information to improve long-term cryopreservation method of bester semen in future.