In polyculture, ponds are stocked together with several species of different feeding habits. It is impossible
to target feeding to only high-valued species, because low-valued species would consume the feed
resulting in economic inefficiency unless a suitableintegrated system is adopted. Compared to the
nutrient utilization efficiency of about 30% in most intensive culture systems (Beveridge and Phillips,
1993; Acosta-Nassar et al., 1994), the nutrient utilization efficiency could reach more than 50% in
integrated cage-cum-pond culture systems, resulting in the release of much less nutrients to the
surrounding environment (Yi, 1999). In case of poor farmers, they have limited financial resources so they
can not turn their whole ponds to culture high-valued species using expensive commercial feed. However,
the integrated cage-cum-pond system may provide an opportunity for small-scale farmers to use their