Adaptation and domestication of endangered wild betta fish (Betta channoides) originating from East Kalimantan, Indonesia

Betta channoides is an endemic freshwater fish species in Indonesia; however, it has been classified as endangered due to its declining wild populations. As part of the efforts in conserving wild B. channoides populations, this study was conducted to establish a methodology for adapting and domesticating B. channoides through breeding and restocking initiatives. B. channoides samples were successfully acclimated and bred in captivity in Depok City, West Java, Indonesia, which is significantly distant from its native habitat in Pampang Village, Samarinda City, East Kalimantan, Indonesia. A glass aquarium was the most suitable rearing container for inducing minimal stress, as indicated by the lowest blood glucose levels recorded (43.67 ± 8.34 mg/dL in males and 59.00 ± 9.00 mg/dL in females). Chironomus sp. larvae served as the optimal nutrition source for gonadal maturation, resulting in enhanced weight gain (0.32 ± 0.07 g in males and 0.38 ± 0.12 g in females) and the highest number of mature fish (seven males and six females). The size of males exhibited a more significant effect on egg production, as demonstrated by higher R ² values for length (0.3311) and weight (0.2749). After the yolk absorption period of 7 days, the larvae were fed for the first time. The detailed analysis of the reproductive traits and early developmental stages of B. channoides contributes to our understanding of its biology and serves as a foundation for further improvements in captive breeding and aquaculture methodologies.