The farmers of the Apatani tribe in Arunachal Pradesh, India have been raising a concurrent crop of fish successfully in their mountain valley rice plots for the past 40 years. They follow indigenous rice agronomy, ignoring the use of fertilizers, pesticides and even supplementary feed for the fish reared in the system. However, the yield levels of fish, ranging from 250 to 500 kg ha−1season−1, clearly support the role of other available resources within their wet rice fields. The investigation revealed that the rice itself provided the substrates for colonization and growth of periphyton. The colonized periphytic contents (1406–13513 no. cm−2 stem−1) on rice stems and other natural fish feeds within the system seem to have direct effect in this regard. The Apatani technique of rice–fish integration may be considered as one of the periphyton-based aquaculture (PBA) systems which deserve further research attention.
