Successful fertilization and hatching of four European cyprinid species using cryopreserved sperm

Abstract

In this study we tried to develop a uniform method of sperm cryopreservation for four cyprinid fish species indigenous to Hungarian waters: the roach (Rutilus rutilus L.), the bream (Abramis brama L.), the silver bream (Blicca bjoerkna L.) and the barbel (Barbus barbus L.). The sperm was frozen in liquid nitrogen vapor in the presence of five extenders (350 mM fructose, 30 mM Tris, pH 8.0; 350 mM glucose, 30 mM Tris, pH 8.0; 300 mM sucrose, 30 mM Tris, pH 8.0; 200 mM KCl, 30 mM Tris, pH 8.0 and modified Kurokura’s extender) and two cryoprotectants: 10% methanol (MeOH) and 10% dimethyl-sulfoxide. The highest post-thaw motility (roach: 77 ± 6%, bream: 77 ± 6%, silver bream: 67 ± 5%, barbel: 75 ± 6%), fertilization (roach: 84 ± 4%, bream: 83 ± 2%, silver bream: 63 ± 2%, barbel: 70 ± 4%) and hatching (roach: 74 ± 2%, bream: 67 ± 6%, silver bream: 54 ± 2%, barbel: 61 ± 4%) rates were found when either fructose or glucose extenders were used in combination with MeOH as cryoprotectant for all four investigated species. Strong correlations were found between post-thaw motility of the sperm and fertilization or hatching rates, which indicates that motility can be used to predict fertilization success in these species.