Effects of size asymmetry on aggression and food acquisition in Arctic charr

Abstract

The feeding rate of a group (DS) of two small, two medium and two large 1 + Arctic charr Salvelinus alpinus was higher than in a group of six fish of the same size (SS), suggesting that size distribution had an effect on feeding behaviour, with a correlation between the size of the fish and the amount of food eaten - the largest fish eating the most. Against predictions, rate of aggression was not higher in the SS groups; rather there was a modest tendency of higher aggression among individuals in the DS groups. (C) 2000 The Fisheries Society of the British lsles.