A sperm cryopreservation protocol adapted from turbot, was tested on sea bass using either 250-mu L straws or 1.5-mL cryovials. A dilution to 1/3 in Mounib's extender and a cooling rate of 65 degrees C.min(-1) allowed frozen sperm to recover an initial motility similar to that of fresh sperm at thawing; however, significant differences in motility (P < 0.001, n = 10 fish semen) were observed at further post-activation times, the motility decrease being faster in thawed sperm. At the experimental scale, triplicate inseminations of 2-mL aliquots (approximately 2 000 eggs) showed a significant fertility decay of thawed sperm compared to that of fresh sperm (P < 0.01, n = 12 fish semen) when a discriminating 35.10(3) spermatozoa to egg ratio was applied.... |