Aggressiveness and kinship in brown trout (<i>Salmo trutta</i>) parr

Abstract

In a series of experiments, kin-biased behavior of young brown trout (Salmo trutta) was observed. The aggressiveness shown by groups of familiar siblings (siblings reared together since fertilization) and groups of unfamiliar siblings (siblings reared apart since fertilization) was significantly lower compared to that of mixed groups of two unrelated sibling groups (offspring of two different pairs of parents). The evolution of kin-biased behavior, as shown by a reduction in aggressiveness, is assumed to have evolved through a kin-selective mechanism.[Behav Ecol 7: 445-450 (1996)]