Asian red-tailed catfish Hemibagrus wyckioides is an omnivorous freshwater fish which is commonly found
within the Mekong River Basin (Prasertwattana et al. 2005). The red-tailed catfish reared in several Asian
countries are well accepted by consumers as food fish (Sahoo et al. 2010). This species is the largest bagrid
catfish in Asia and can reach 80 kg in the wild (Ng and Rainboth 1999). The body length of H. wyckioides can
increase from 0.85 to 3.25 cm in 6 weeks, and the specific growth rate may reach up to 10.23 %/day
(Amornsakun 2000). In addition, H. wyckioides grows and develops well in waters which have different
chemical compositions and temperature ranges. H. wyckioides eats a wide variety of prepared, frozen and live
foods, which makes it an excellent species for intensive aquaculture (Ng and Rainboth 1999). Now that H.
wyckioides is popular in cage culture in the Mekong River Basin (Prasertwattana et al. 2005), this has led to a
high demand for H. wyckioides fingerlings for stocking in grow-out cages. Stocking density, quality of feed
and water quality management are some of the important factors to be considered during intensive aquaculture.
Stocking density plays a crucial role in determining the growth and survival, and ultimately the fish or
seed production, in an intensive system (Sahoo et al. 2010). The negative impact of density on growth and
survival has been widely reported when raising catfish (Dada et al. 2000; Sahoo et al. 2004). However, a