Effect of Different Stocking Densities on Growth and Production Performances of Chevron Snakehead Channa striata in Fiberglass Tanks

摘要

Grow-out culture trials of the highly valued Chevron Snakehead Channa sriata were carried out under different stocking densities in fiberglass tanks. Fingerlings stocked at 20 individuals/m(2) were designated as treatment 1 (T1), 30 individuals/m(2) as treatment 2 (T2), and 40 individuals/m(2) as treatment 3 (T3). The initial mean +/- SE body weights (1.93 +/- 0.01, 1.57 +/- 0.16, and 1.90 +/- 0.02 g, respectively) and initial mean +/- SE body lengths (6.22 +/- 0.05, 5.86 +/- 0.20, and 6.26 +/- 0.01 cm, respectively) of snakeheads at stocking were similar in all the treatments. After stocking, fish in all the experimental tanks were fed commercial pellets containing 44% crude protein and 6% crude fat. The feed was given at a rate of 6% of the estimated body weight of fish twice daily (0900 and 1700 hours). Physicochemical water quality conditions such as temperature, dissolved oxygen, pH, and total ammonia nitrogen were maintained within the suitable range for fish culture. Final weight, final length, and weight gain of snakeheads were significantly higher in T1 than in T2 and T3. The specific growth rate (SGR) was significantly (P 0.05) higher in T1 and T2 than in T3. The best feed conversion ratio (FCR) was obtained by fish in T2, followed by those in T1 and T3. Survival was slightly higher in T1 and T2 than in T3, but no significant differences were recognized among the treatments. Despite this, the significantly highest gross and net productions of snakehead were obtained at the highest density (T3) and the lowest at the lowest density (T1). Therefore, in terms of production, a stocking density of 40 individuals/m(2) may be recommended for the large-scale culture of Chevron Snakehead in captivity.