CRYOPRESERVATION OF TURBOT (SCOPHTHALMUS-MAXIMUS) SPERMATOZOA

The aim of this study was to develop a method for cryopreserving turbo t semen and to compare sperm motility characteristics, metabolic statu s and fertilization capacity of frozen-thawed and fresh semen. The bes t results were obtained when spermatozoa were diluted at a 1:2 ratio w ith a modified Mounib extender, supplemented with 10% BSA and 10% DMSO . For freezing sperm samples, straws were placed at 6.5 cm above the s urface of liquid nitrogen (LN) and plunged in LN. The straws were thaw ed in water bath at 30 degrees C for 5 sec. Use of this simple method resulted in a 60 to 80% reactivation rate of the thawed spermatozoa. A lthough the percentage of motile spermatozoa in the Frozen-thawed seme n samples was significantly lower than in fresh semen, spermatozoa vel ocity and respiratory rate remained unchanged. The process of cryopres ervation significantly decreased intracellular ATP content. The fertil ization rate of frozen-thawed spermatozoa was significantly lower than that of fresh spermatozoa, but it increased with sperm concentration. (C) 1997 by Elsevier Science Inc.