[Cryopreservation of sperm from Neolissochilus benasi]

Cryopreservation of sperm from Neolissochilus benasi was studied in 2011. The effects of various cryoprotectants of different concentrations, dilution ratios of milt to extender, storage volume and thawing temperature on motility of post-thawing of spermatozoa were examined to optimize cryopreservation procedures. Semen was stored in liquid nitrogen in 1.8 mL cryovial for 24 h, and the intensity of sperm motility was measured before and after cryopreservation. Post-thawing motility of frozen sperm obtained with cryoprotectants 10% MeOH or 15% EG were higher than for others. The most effective dilution ratio of milt to extender is 1:7. The maximal storage volume is 60 μL of 1.8 mL cryovial and the optimal sperm equilibration period in the extender D-15+10% MeOH was between 10-60 min. Thawing was optimal in a 37 Degrees Celsius water bath. When fresh sperm motility is (62.33±2.05)%, this cryopreservation protocol resulted in frozen-thawed semen with 20%-30% motile. The overall effect is not ideal, and cannot achieve extensive application. Different breeding management of different ground protection may have contributed to this result. Therefore, it is necessary to reduce stress capture induced in management of parent fish and provide suitable forming conditions. In the ex situ conservation of rare fish the broodstocks management of males is as important as that for females and the key to obtaining high quality larval fish.