Pengaruh Penambahan Gliserol dan Ethanol Dalam Proses Kriopreservasi Sperma Ikan Jurung (T. soro) di Balai Benih Ikan, Samosir, Danau Toba

Abstract

Jurung fish (Tor soro), also known as Batak fish, is an endemic species of Lake Toba waters that is currently endangered due to habitat degradation, the introduction of alien species, and the difficulty of obtaining broodstock with mature gonads. One promising conservation effort is sperm cryopreservation technology. This study aimed to determine the effect of cryoprotectant type and concentration on the motility and viability of Batak fish sperm after cryopreservation, as well as to assess DNA integrity following freezing. Two types of cryoprotectants were used—glycerol and ethanol—with seven concentration variations (0%, 2.5%, 5%, 7.5%, 10%, 12.5%, and 15%), including a control without cryoprotectant. Observed parameters included sperm motility, viability, and DNA integrity. The results showed that glycerol at a concentration of 7.5% yielded the best results, with motility of 28.67% and viability of 63%, approaching control values. Ethanol produced lower and inconsistent results. Electrophoresis tests showed no DNA fragmentation in any treatment. Therefore, 7.5% glycerol is recommended as the optimal cryoprotectant for jurung fish sperm cryopreservation. This study provides important contributions to the conservation of endemic fish species through cryopreservation technology.