Express yourself: Bold individuals induce enhanced morphological defences

Abstract

Organisms displayanimpressive arrayofdefence strategies innature. Inducible defences (changes in morphology and/or behaviour within a prey's lifetime) allow prey to decrease vulnerability to predators and avoid unnecessary costs of expression. Many studies report considerable interindividual variation in the degree to which inducible defences are expressed, yet what underlies this variation is poorly understood. Here, we show that individuals differing in a key personality trait also differ in the magnitude of morphological defence expression. Crucian carp showing risky behaviours (boldindividuals)expressed a significantly greater morphological defence response when exposed to a natu-ralenemywhencompared withshy individuals. Furthermore,weshowthat fish of different personality types differ in their behavioural plasticity, with shy fish exhibiting greater absolute plasticity than bold fish. Our data suggest that individuals with bold personalities may be able to compensate for their risk-prone behavioural type by expressing enhanced morphological defences. 2013 The Author(s) Published by the Royal Society. All rights reserved.