Effects of enrichment on the development of behaviour in an endangered fish mahseer (Tor putitora)

Structural enrichment in the rearing environment, not only promotes fish welfare, but also affects several aspects of behavioural biology of fish in aquaculture. Here an attempt was made to use physical-enrichment to improve the behaviour of hatchery-reared fish. In this study, three groups of 15 days old mahseer (Tor putitora) hatchlings were reared up to advanced fry stage in barren (without any substrate), physically-enriched (gravel bed, substrate and plants) and semi-natural environments (earthen pond having a natural feed) respectively and the behavioural profiles of fish from these environments were compared. We illustrate that increased structural complexity during early life significantly affect various behavioural characteristics of the fish. Exploratory behaviour, predation and anti-predatory response were significantly (p ˂ 0.05) higher in fish reared in physical enrichment and semi-natural environment than in barren-reared fish. These results have important implications for a possible way of improving the outcomes of restocking program of endangered fish species by modifying conventional hatchery-rearing environments.