EFFECT OF ANTIOXIDANT AND ITS CONCENTRATION ON THE SPERM QUALITY OF WALKING CATFISH Clarias batrachus POST CRYOPRESERVATION

The walking catfish Clarias batrachus is popular and affordable in Southeast Asian countries. The development of breeding technology for this species is ongoing, with sperm cryopreservation being a key aspect of study that supports its breeding program. Cryopreservation is an essential method in fish breeding, particularly for sustaining breeding initiatives that supply larvae throughout the years. However, this process can lead to oxidative stress, which may decrease sperm quality due to structural and physiological damage, including DNA fragmentation. Adding an antioxidant to the freezing medium could help mitigate these negative effects and maintain sperm quality. This study aims to evaluate the effectiveness of various types and concentrations of antioxidant on the quality of C. batrachus sperm post-cryopreservation. Four types of antioxidants were tested: ascorbic acid, Myoinositol, alpha-tocopherol, and Butylated Hydroxytoluene, each at concentrations of 0, 20, 40, and 60 mg/L. Ringer solution, 5% DMSO and 5% egg yolk were used as extender and cryoprotectants, respectively. Sperm samples were stored in liquid nitrogen for 2 weeks, after which sperm quality was analyzed. The results showed that both the type and concentration of antioxidant had a significant effect (p<0.05) on all measured sperm quality parameters. Ascorbic acid at a concentration of 40 mg/L produced the best results, achieving 62.33% motility, 66.00% viability, and 61.67% fertility. Electrophoresis analysis showed no DNA fragmentation in any of the treatments, indicating that the genetic structure of sperm remained intact. Ascorbic acid at 40 mg/L is the most effective antioxidant for cryopreservation of sperm C. batrachus.