Enrichment promotes learning in fish

Abstract

Captive birds and mammals reared in enriched rearing environments have been shown to behave more flexibly compared to animals reared in impoverished or plain environments. Recent evidence has shown that this is also true for fish; enrichment promotes faster recovery after a stress- ful experience, a higher propensity for exploration of novel areas and the development of more sophisticated social behaviour. Here we report how enrichment influences social learning in juvenile cod Gadus morhua that were reared in either spatially enriched or plain tanks. Naive juvenile cod were allowed to repeatedly observe experienced tutors as they foraged on gammarid or mysid prey, or control tutors that acted as social stimuli but did not forage. The naive fish then received a mixture of mysid and gammarid prey. Enriched-reared fish improved their ability to consume live prey in the presence of foraging tutors, but plain-reared fish did not. Although gammarids were consumed more often and more quickly than mysids, both among tutors and naive fish, social learning from tutors demonstrating mysid hunting and consumption had its greatest effect on social learning in the enriched fish.