Cryopreservation of muskellunge and yellow perch semen

Effect of four extenders on the success of cryopreservation of the semen of muskellunge Esox masquinongy and yellow perch Perca flavescens was tested. These extenders consisted of 0.45 M sucrose and were supplemented with eit her (1) 15% dimethyl sulfoxide (DMSO), (2) 15% DMSO and 10% hen's egg yolk, (3) 15% dimethylacetamide (DMA), or (4) 15% DMA and 10% egg yolk. The use of extender with DMA alone yielded only about 7% muskellunge sperm fertiliz ing ability after cryopreservation. Supplementation of this extender with e gg yolk produced a fertilization rate (36.6% of the control where fresh spe rm was used) not significantly different from rates obtained with extenders containing DMSO. No significant differences were found among particular po ols (consisting of semen from three different males per pool) of muskellung e semen used in this experiment. Fertilization rates of cryopreserved yello w perch semen (range, 69.6% to 77.3%) were not significantly different amon g all extenders tested. Cryopreservation success differed significantly bet ween milt samples from individual yellow perch males. Yellow perch eggs cou ld be stored up to 77 min at 10 degrees C (fertilization success ranged fro m 57.2% to 64.8%). Our results provided 25-35% improvement of cryopreservat ion technology for yellow perch semen (measured as fertilization rate) and new data for cryoprotectant use in muskellunge. We were also able to prolon g in vitro viability of yellow perch eggs during storage compared with earl ier attempts.