Diet-specific chemical cues influence association preferences and prey patch use in a shoaling fish

In many social species individuals have to make adaptive decisions about with whom to group. Self-referent matching of chemical social information specific to patterns of diet and habitat use is an important factor underlying social organization in shoaling fishes. In a series of three experiments, we gave female Whitecloud mountain minnows, Tanichthys albonubes, a binary choice between shoaling with stimulus groups fed upon the same or a different diet to themselves. Focal fish spent significantly more time shoaling with the group whose individuals had consumed the same diet as themselves, were significantly more likely to follow such a group when the two stimulus groups diverged in a simulated shoal fission event, and were significantly more likely to feed from a prey patch containing a neutral food that was situated close to the same diet stimulus group than from an identical one located close to the stimulus group fed the alternative diet. By grouping with others that are exploiting the same resources, individuals potentially gain useful information about the location of resources.