Upaya Domestikasi Melalui Pembesaran Ikan Gabus (Channa striata) di Dalam Wadah Terkontrol
The striped snakehead or snakehead murrel (Channa striata) is a valuable food fish with a wide distribution in Asia, including Central Sulawesi. Data on C. striata resources in Central Sulawesi are extremely limited. Culture of this species is well advanced in India but as yet undeveloped in Indonesia and in particular in Central Sulawesi. A program was initiated in early 2013 to collect data on C. striata populations in two Districts (Sigi and Morowali Utara). Grow-out trials were also undertaken with seed and/or broodstock from these wild stocks. A field survey in Morowali identified several stocks, however from a bio-ecological point of view, there were indications that all were under pressure from fishing and environmental degradation. There were strong indications of declines abundance and average as well as maximum size. Early domestication efforts with seed from Sigi were successful in rearing fry (total length TL±SD 43.9±3.3mm; weight W±SD 0.78±2g) for a period of 70 days. The three feed regimes (treatments) used for the grow-out trials in concrete tanks were A: mosquito larvae; B: commercial feed; and C: a combination of both. There were 3 replicates of each treatment with 10 fish per unit (N=90). At both 30 and 70 days, both A and C were significantly different (F>Fcrit,?=0.01) from treatment B which produced the lowest biomass and average individual growth. For the first 30 days there was no significant difference between A and C, while after 70 days C produced the highest biomass, while A was significantly different from C (F>Fcrit,?=0.05) for biomass. Survival rate of B was significantly lower than C (100%) at both 30 and 70 days (F>Fcrit,?=0.01). Survival rate of A was not significantly different from B or C at 30 days but was significantly different from both (F>Fcrit,?=0.05) at 70 days. Cannibalism was the main cause of mortality in A and B, and occurred whenever there was a substantial difference in size. It was concluded that mosquito larvae are one live feed which is suitable for young C. striata fry, but fingerlings of around 60mm TL require additional nutrition which can be supplied by commercial feed. However the commercial feed alone was unsuitable for C. striata fry and fingerlings. Regular grading based on size would be essential to prevent high levels of cannibalism. Analysis of length/weight data revealed an isometric growth pattern (W=aLb) with b=3 and a=0.000008255. The bioecological condition of wild habitats emphasizes the urgency of striped snakehead domestication and the conservation of C. striata resources in Central Sulawesi to enable sustainable use of this species.