In pursuit of modernising fish culture practices, novel recirculatory aquaculture systems (RAS) have been introduced in semi-urban areas of West Bengal and other parts of India.

While quite a few progressive fish farmers in India have adopted advanced, intensive and imported RAS systems featuring huge plant, other farmers have developed small and indigenous RAS systems that require comparatively low investment. This article discusses the design, principles, state-of-the-art and associated practical aspects of indigenous RAS technology as currently practiced in West Bengal and other places.