CRYOBIOLOGY, cilt.66, sa.2, ss.192-194, 2013 (SCI-Expanded)
Post-thaw motility rate, curvilinear velocity (VCL), and fertilizing ability of carp spermatozoa can be improved by short-term treatment with moderately hypotonic media prior to freezing. Before cryopreservation, carp sperm samples were treated with NaCl solutions of differing osmolalities, ranging from 100 to 300 mOsm kg−1 for 10 s, after which final osmolality was adjusted to 300 mOsm kg−1. The resulting sperm suspension was diluted 1:1 with cryoprotective medium and frozen using conventional techniques. Control samples were treated in the same way, without the pre-dilution step. Post-thaw motility rate in samples pretreated with 200 mOsm kg1 NaCl was significantly higher (44 ± 10%) than in controls (21 ± 15%) and samples pretreated with 100 mOsm kg−1 (25 ± 15%) and 300 mOsm kg−1 (25 ± 12%) NaCl. Significantly higher mean VCL were observed in samples pretreated with 100, 150, and 200 mOsm kg−1 (119 ± 24, 118 ± 22, and 115 ± 32 μm s−1, respectively) compared to controls (92 ± 27 μm s−1). Fertilization rate of frozen-thawed sperm treated with 200 mOsm kg−1 solution of 2 M NaCl was significantly higher (25 ± 18%) than that of sperm treated with 300 mOsm kg−1 NaCl solutions (12 ± 7%) and the control (9 ± 6%).