Original Paper

Behavioral Ecology and Sociobiology

, Volume 67, Issue 4, pp 667-673

First online:

Shoaling fish can size-assort by chemical cues alone

  • Ashley J. W. WardAffiliated withSchool of Biological Sciences, University of Sydney Email author 
  • , Suzanne CurrieAffiliated withDepartment of Biology, Mount Allison University

Rent the article at a discount

Rent now

* Final gross prices may vary according to local VAT.

Get Access


Animals that form groups are typically assorted by phenotype. For example, fish shoals are notably composed of closely size-matched individuals, yet the sensory mechanisms that promote this behaviour have not been fully determined. Here, we show that two freshwater shoaling fish species, three-spined stickleback and banded killifish, have a greater preference for the chemical cues of conspecifics that are the same size as themselves than for those of larger or smaller conspecifics. We suggest that this ability to determine their own size relative to conspecifics may be based on chemical self-referencing. This provides a novel insight to the mechanisms underlying a widespread phenomenon in social behaviour, and provides further evidence of the crucial role played by chemical cues in structuring the interactions of fishes.


Shoaling Schooling Sociality Olfaction Sensory ecology