Growth performance of Trichogaster pectoralis Regan in intensively cultivated rice fields

Trichogaster pectoralis Regan is often cultured successfully in rice fields in South-cast Asia. However, since the advent of high-yielding rice variet ies and intensive rice cropping, several reports suggest poorer growth perf ormance of the species. In this paper, we investigated the growth performan ce of T. pectoralis in rice-fish systems characterized by intensive rice cu lture and extensive to semi-intensive polyculture of Oreochromis nilotictis (L.), Cyprinus carpio L. and Barbodes gonionotus (Bleeker). In these syste ms, T. pectoralis recorded negative net productions. This was mainly the re sult of a negative specific growth rate (SGR) when fish had to stay in the trench (-0.519% body weight day(-1)) or when fish had free access to the ri ce crop (-0.081). Only when harvested rice plants were allowed to generate new tillers (ratooning) did T. pectoralis perform slightly better (0.453% b ody weight day(-1)). The SGR of T. pectoralis was low owing to a lack of fo od in intensive rice systems. The other species, all with SGR values higher than 1% body weight day(-1), clearly had a competitive advantage over T. p ectoralis. We concluded that intensification of rice cropping did indeed re sult in poor T. pectoralis growth. Successful T. pectoralis culture is only possible in areas of traditional rice cropping.