Experiments were carried out on the cryopreservation of common carp (Cyprinus carpio L.) sperm. Optimal conditions for fertilization including suitable medium and sperm:egg ratio were determined. Sperm was diluted in modified Kurokura's 'Extender 2' containing DMSO as cyroprotectant in 10% final concentration. The dilution rate was 1:9 (sperm:diluent). Sperm was diluted and equilibrated (10 min) at 2°C. Sperm was then frozen in plastic straws (0.5 ml) at the following rate: 0°C-4°C: 4°C min-1; -4°C-80°C: 11°C min-1; from -80°C they were plunged directly into liquid nitrogen (-196°C). Frozen samples were thawed in a water bath at 40°C. Fertilization rates achieved were much higher in water than in other solutions. Optimal ratios of frozen sperm:egg:water (1:20:20 in volume) and optimal number of frozen spermatozoa:egg (105 spz: 1 egg) were determined. In such conditions, a strong positive correlation (c = +0.846) was found between the post-thaw motility and the fertility of frozen sperm securing high fertilization (99.6%, percent of control). No significant difference was found between fertilization and hatching rates achieved using frozen-thawed common carp sperm.
|Number of pages||3|
|Journal||Journal of Applied Ichthyology|
|Publication status||Published - Jul 1996|
ASJC Scopus subject areas
- Aquatic Science