Aggressive behaviour of four salmonid species in duoculture

Abstract

Aggressive behaviour of groups of eight parr in different species combinations was studied to investigate the potential of duoculture in rearing of salmonids. The species used were Atlantic salmon (Salmo salar L.), sea trout (Salmo trutta L.), Arctic charr (Salvelinus alpinus L.) and domesticated rainbow trout (~ncorh~nchumsy kiss Walbaum). Aggression was assessed by recording seven behavioural patterns. The dominant species in each duocombination can roughly be deduced from decreasing aggressive potential in the following ranking: 1. Rainbow trout (high); 2. Sea trout; 3. Atlantic salmon; 4. Arctic charr (low). Each combination was investigated within and between species as: relative interspecific and intraspecific aggression, size hierarchy effect, and general characteristics of each combination.