Stocking density-dependent growth and survival of Asian red-tailed catfish (Hemibagrus wyckioides) fries: early nursing in cages

Asian red-tailed catfish (Hemibagrus wyckioides) were raised at five different stocking densities in cages (submerged and with a volume of 1 m3) suspended in a fish pond from July to August 2012. H. wyckioides fries (mean weight 0.8 ± 0.1 g) were stocked at densities of 25, 50, 100, 200, and 400 fish/m3. At the end of 56 days, the mean fish weights among the stocking densities of 25 and 50 fish/m3 were significantly lower than those of the 100, 200, and 400 fish/m3 density. The specific growth rates and final mean weights amongst fish reared in higher stocking densities of 100, 200, and 200 fish/m3 were higher than those of the low stocking densities of 25 and 50 fish/m3. Asian river catfish performed poorly at the lowest density. The results indicate an initial lower stocking threshold for Asian red-tailed catfish fries of above 100 fish/m3. The Asian red-tailed catfish fries reared in small cages placed in a pond reached the size 5–6.6 g within a 56-day nursing period.