Cryopreservation of tongue sole Cynoglossus semilaevis sperm

Abstract:

Cryopreservation of tongue sole Cynoglossus semilaevis sperm offers benefits for artificial propagation, hybridization, gynogenesis and sex control.In order to develop a protocol to freeze tongue sole sperm,the effects of cryoprotectants, extenders and dilution ratio on motility,fertilization rate and hatching rate of frozen-thawed sperm were evaluated. Dimethylsulfoxide(DMSO)provided higher protection than glycerol and 1,2 propylene glycol during freezing and thawing.Motion time and life of sperm in A(MPRS +28 mol/L DMSO)and B(TS-2+2.8 mol/L DMSO)before freezing were 37.75±6.45 sec and 145.00±78.98 sec,which was not different from that of fresh sperm(P>0.05).The motility and life of frozen thawed sperm in A were 5350±669% and 98.00±13.51 sec,which was significantly higher than that of frozen thawed sperm in B.When sperm were diluted with A at a ratio of 1∶05,1∶1,1∶15 and 1∶2, the highest motility(82.5±3.54%, 1∶1 dilution ratio)of frozen-thawed sperm was obtained and which was significantly higher than that of other dilution ratio treatment.According to the results above, tongue sole sperm were cryopreserved successfully with MPRS+2.8 mol/L DMSO at a dilution ratio of 1∶1.As a result,the fertilization rate(55.0±5.0%) and hatching rate(35±13.23%) of frozen-thawed sperm were obtained,which was not significantly different from that of fresh sperm(P>0.05).