Kin recognition in zebrafish, Danio rerio, is based on imprinting on olfactory and visual stimuli

The evolution of cooperative behaviour requires mechanisms to avoid investing in conspecifics that are not increasing an individual's direct or indirect fitness. This suggests that selection should favour the capability of recognizing kin. One mechanism to discriminate between kin and nonkin is based on phenotype matching, when an individual learns a template of itself or of its kin and can later use this template to recognize even unfamiliar kin. In this study, we found that in zebrafish olfactory kin recognition depended on an imprinting process that required the two-step learning process of olfactory as well as visual cues of kin. Larvae that were exposed to either visual or olfactory cues or to both cues of nonkin did not show imprinting. This capability of imprinting on kin but not on nonkin cues can be explained by genetic predisposition or self-referencing. Through this combined imprinting process larvae can avoid false imprinting on unrelated individuals. (c) 2013 The Association for the Study of Animal Behaviour. Published by Elsevier Ltd. All rights reserved.