Individuality in Fish Behavior: Ecology and Comparative Psychology

This work is a brief review of a series of studies of the phenotypic organization and ecological significance of individual differences in fish behavior. The following species were studied: guppy Poecilia retuculata, lion-headed cichlid Steatocranus cassuarius, and the convict cichlid Archocentrus nigrofasciatum. We developed methods for the analysis of individual differences in fish behavior and studied their structure, development, and ecological and evolutionary significance. This paper was published as: Budaev, S.V. and Zworykin, D.D. (2002). Individuality in fish behavior: Ecology and comparative psychology, Journal of Ichthyology, vol. 42, Supplement 2, S189-S195. 1 Current address: Centre for Neuroscience, School of Life Sciences, University of Sussex, Brighton. BN1 9QG, UK Individual differences in animal behavior are attracting more and more interest of researchers (Slater, 1981; Dunbar, 1982; Caro and Bateson, 1986; Clark and Ehlinger, 1987; Mendl and Deag, 1995). Such an interest is especially pronounced to the behavior of fishes (Magurran, 1993; Wilson @et al.,@ 1994; Coleman and Wilson, 1998). Many studies have revealed substantial differences between conspecifics in feeding, defensive, sexual, and other behaviors (see reviews by Ringler, 1983; Magurran, 1993). Significant individual differences were found even in the behavior of fish in school (Radakov, 1972; Helfman, 1984; Magurran, 1993; Pitcher and Parrish, 1993), which was for a long time considered as the most homogenous social structure (Shaw, 1970; Radakov, 1972). Even the classical example of many textbooks, the stereotypic response of male three-spined sticklebacks (@Gasterosteus aculeatus@) to red stimuli, is very variable in different individuals. It differs so significantly (very pronounced in some individuals and completely absent in other), that the classical concept of innate releasing mechanisms can be questioned (Rowland, 1982; Baerends, 1985; Bolyard and