Effect of Different Extenders and Dilution Ratios on the Spermatological and Fertilization Parameters of Cyprinus carpio During Cryopreservation.

Production of quality seeds is a critical need, and cryopreservation serves as an important biotechnological tool in achieving that goal. In the present study, the effects of different extenders and dilution ratios on the spermatological and fertilization parameters of cryopreserved milt were evaluated in common carp brooders. Milt was collected from Cyprinus carpio brooders and diluted and cryopreserved at three dilution ratios such as 1:40, 1:80, and 1:120, using Freshwater Fish Saline (FWFS) and Modified Fish Ringer as extenders and dimethyl sulfoxide as cryoprotectant (90:10). Motility duration, fertilization, and hatching rates were studied after different treatments. Rapid freezing of straws was done for 20 minutes at a freezing rate of -78°C/min. It can be concluded that C. carpio milt can be cryopreserved with FWFS at a dilution ratio of 1:40 to obtain the highest post-thaw motility duration (60.33 ± 1.52 seconds), fertilization rate (87.6% ± 1.52%), and hatching rate (57.1% ± 4.16%). The difference in the values between extenders, dilution ratios, and cryopreserved and fresh milt were statistically significant (p < 0.05) when analyzed using ANOVA.