Summary

Fishes have been central to our understanding of many of the major aspects of contest behaviour, extending from Tinbergen's early work on social releasers to some of the initial tests of assessment models and now to the neuroendocrine and genomic regulation of aggression and dominance. In this chapter, we focus on some exciting areas of research in fish contest behaviour that promise to shed light on the multidimensionality of resource holding potential (RHP), sex- and size-related differences in decision-making during contests, whole-organism performance and fight outcomes, selection and potential constraints on contest behaviour; and the role of developmental plasticity in driving RHP-related phenotypic variation. We have developed this chapter more as a prospectus than a review, using the concrete foundation laid down by numerous researchers to highlight areas that could be of great import in the years to come. This approach, of course, leaves us with many unanswered questions that we hope will serve as a springboard for rigorous hypothesis testing using an integrative framework for fish contest behaviour.

Introduction

The formal study of fish aggression has a long and prolific history dating back at least 70 years to a curious observation of three-spined sticklebacks, Gasterosteus aculeatus, responding intensely to a red postal truck that would occasionally pass the window of Niko Tinbergen's laboratory (Kruuk 2003, p. 87). What triggered aggression in the sticklebacks, of course, was not the truck but rather the colour red, a trait that males boast on their throat and ventral surface during the breeding season (ter Pelwijk & Tinbergen 1937), and that might indicate an imminent threat to a resident male's territory (Bolyard & Rowland 1996). Tinbergen and his contemporaries subsequently made significant efforts to identify behavioural, morphological and chromatic ‘releasers’ of aggression (e.g. Seitz 1940, Tinbergen 1948 and references in Earley et al. 2000).