Effect of different cyroprotectants for spermatozoa cyropreservation of orange mud crab, Scylla olivacea (Herbst, 1796)

Abstract

The objectives of this study were to determine the effect of cryoprotectants and sperm density for a long-term storage of S. olivacea spermatozoa. Spermatozoa were obtained by homogenized the spermatophores by a glass homogenizer in an ice-bath and centrifugation at 4 ° C. Spermatozoa were suspended in calcium-free saline (Ca-F saline) containing the cryoprotectants glycerol, dimethyl sulfoxide (DMSO) and methanol at concentration of 5%. Sperm which were vibrated and rotated was counted as live in sperm viability assessment. Samples of spermatozoa were cooled to -196 ° C by two-step freezing, first to -80 ° C and then by plunging in liquid nitrogen (LN). Gradual cooling (1 ° C min- 1 ) was done by cooling the spermatozoa. Thawing was done at 30 ° C water bath for 2 min. This yielded live sperm after storage in LN for 30 days. The best sperm viability was obtained from density of 10 8 cells per ml in DMSO. There is no significant different (P > 0.05) between cryoprotectant toward sperm viability. However, there is a significant different (P < 0.05) between density toward the sperm viability.