The spermatozoa viability of kancra fish (Tor soro, Valenciennes 1842) 48-hour after freezing: Effect of brown sugar as natural cryoprotectant

Kancra fish (Tor soro, Valenciennes 1842) is one of the endemic fish in Indonesia which population keeps decreasing due to degradation of the environment. Conservation is needed and cryopreservation is an effective strategy in this regard. Brown sugar as a natural cryoprotectant has the potential to substitute less eco-friendly synthetic cryoprotectant. The study was carried out to determine the viability of T. soro spermatozoa after 48 hours of cryopreservation using brown sugar. Sperm sample were collected through stripping method. The ejaculated sperm were diluted using the extender (brown sugar-fish ringer + methanol 10%, 1:9). The brown sugar concentration examined were 0%, 5%, 10%, 15%, 20%, and 25%, and the sample was equilibrated at 4 °C for 10 minutes, and frozen at-10 °C for 48 hours. The process was followed by thawing process ast 40 °C for 60 seconds. Data were analyzed using ANOVA, followed by Tukey test. The results showed that brown sugar concentration of 15% significantly affects viability of the sperm after 48 hours of cryopreservation with 83.75±1.71% (p<0.05). However, a study is needed to determine the effectivity of brown sugar as a cryoprotectant.