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

Abstract

Betta channoides is an endangered freshwater fish endemic to Indonesia. This study was conducted to establish a methodology for adapting and domesticating B. channoides through breeding and restocking initiatives. Fish were successfully acclimated and bred in captivity in Depok City, West Java, Indonesia, which is significantly distant from its native habitat in East Kalimantan. A total of 100 immature fish (50 males and 50 females) were collected from the wild. The study consisted of three main experiments: (1) evaluation of rearing containers (Styrofoam box, plastic container, and glass aquarium) for 30 days with three replicates using five males and females (maintained separately); water temperature, pH, and ammonia were 27.5–30.8 °C, 5.2–5.6, and 0.004 mg/L, respectively; (2) gonadal maturation using Moina sp., mosquito larvae (Culex sp.), and bloodworms (Chironomus sp.) for 30 days without replication, using eight males and females in glass aquariums with water quality of 27.9–30.8 °C, 5.3–5.7, and 0.004 mg/L; and (3) breeding of 12 male–female pairs. A glass aquarium was the most suitable rearing container for inducing minimal stress, as indicated by the lowest blood glucose levels recorded. Chironomus sp. larvae served as the optimal nutrition source for maturation, resulting in enhanced weight gain and the highest number of mature fish. The number of larvae produced was 30.67 ± 9.23 individuals per spawning. After the yolk absorption period of 7 days, the larvae were fed for the first time. This study provides essential data on the reproduction and early development of B. channoides to support conservation aquaculture strategies.