Bio-economic evolution of snakeheads and Indian major carps culture in IMTA system

An experimental study was carried out for a period of six months to assess the commercial culture potentiality of striped snakehead (Channa striatus) over Indian Major Carps (IMCs) in improved Integrated Multi-Trophic Aquaculture (IMTA) system. Characteristics of snakehead (Channa striatus) make it a desirable culturable fish in IMTA system. The experiment was done in two stepsnursery stage (2 months) and grow-out stage (4 months). In the nursery stage, the stocking density was 30 nos/m3 (2.3±0.42 g). Larvae were fed with finely granule formulated feed containing 43.4% protein at 5% body weight which had FCR of 1.3. The survival rate was 67% in this stage. After two months, 20 nos/m3 fry were collected from the larval rearing tank and their average body weight was 25.6±1.9 g. The collected fishes were transferred into grow-out pond and to utilize all the trophic level of the water, 5 tilapia (Oreochromis mossambicus), 2 silver carp (Hypophthalmichthys molitrix), 1 sarpunti (Barbonymus gonionotus) and 1 rui (Labeo rohita) of comparatively larger size than snakeheads were added in each pond. Stinging catfish (Heteropneustes fossilis) was cultured in cages at 100 nos/ft3 stocking density where snails produced in the bottom were used as a major feed ingredient for catfish. Four floating trays, each 0.11 m2 in surface area, were placed in the ponds for growing lettuce. In grow-out stage, formulated pelleted feed (FCR 1.4) with 34.95% protein was fed at 3% body weight. Here about 93% survival rate was found in grow-out phase. At the end, 25 Kg snakehead/decimal was harvested from improved IMTA system where IMCs were produced at 20 Kg/decimal in traditional IMTA system. But no significant difference (P <0.05) was found in production of stinging catfish and vegetables between the improved and traditional IMTA system. The improved IMTA system possessed a significantly lower (P <0.05) operating ratio (59%) than the traditional IMTA system (65%). Return on sales ratio was 41.18% in improved IMTA which was significantly higher (P <0.05) and confirmed the system to bear the burden of increased cost of production but the profit margin was also higher. Benefit-Cost Ratio (BCR) was 1.7 in improved IMTA system which was significantly higher (P <0.01) than traditional IMTA system (1.54). The innovated improved IMTA system can provide around 16% more profit compared to traditional IMTA system from per decimal pond area. This suggests that IMTA can be promoted through action research and field trial with potential fish farmers towards sustaining economic viability and food security of the poor people.