Feeding behaviour
The mouth of the striped catfish is large, with sharp teeth on the jaws. The gill lamellae of this fish are sparser and shorter than those of species which prefer to eat zooplankton. Its stomach is U-shaped and the intestine is short. Naturally, with the above morphological characteristics, the striped catfish is an omnivore, feeding on algae, higher plants, zooplankton and insects; larger fish also consume fruit, crustaceans and fish, as well as vegetable debris (Poulsen et al., 2008; FAO, 2010–2011; also see http://www.fishbase.org) (Table 1). The food spectrum of striped catfish is therefore broad. Tran (1994) reported that the diet of wild striped catfish was comprised of 37.8 percent small fish, 23.9 percent shellfish, 6.7 percent plant material and 31.6 percent organic detritus. Nguyen, Nguyen and Tran (1979) also found many body parts (including eyes) of juveniles of other fish species in the stomachs of striped catfish (Table 2).
Natural food
After hatching, striped catfish consume zooplankton, as has been shown by the abundance of cladocerans and rotifers in the stomach. During the nursing stage, many kinds of food including Artemia, Tubifex, Moina, rotifers and processed food can be used for striped catfish. However, the highest survival rate and fastest growth has been achieved using Artemia and Tubifex (Le et al., 1998). Striped catfish of 3–4 days old are highly cannibalistic if not fed to satiation. At day 20, juveniles can efficiently use formulated feeds (Le et al., 2000). As noted previously, older fish have a broader food spectrum.
Under culture conditions (e.g. in cages, pens or ponds), the striped catfish can use both formulated and farm-made feeds. The farm-made feed is made from broken rice, vegetables and by-products from factories and is thus low in protein. This characteristic has been important in achieving the rapid expansion of the culture of this species (Truong and Tran, 1993; Le, Pham and Huynh, 2000). In deficient food conditions, striped catfish can also use organic detritus (Tran, 1994).
