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 antioxidant to freezing medium could facilitate to 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, namely 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. Both the type and concentration of antioxidants significantly affected all measured sperm quality parameters (p<0.05). Ascorbic acid at 40 mg/L yielded the highest motility (62.33%), viability (66.00%), and fertility (61.67%) values. Electrophoresis analysis revealed no DNA fragmentation in any treatment, indicating that the genetic structure of the sperm was preserved. Ascorbic acid at 40 mg/L is the most effective antioxidant for cryopreservation of sperm C. batrachus.