| dc.description.abstract | Groups of eight parr of hatchery reared Atlantic salmon (Salmo salar), sea trout (Salmo trutta),
rainbow trout (Oncorhynchus mykiss) and Arctic charr (Salvelinus alpinus) were investigated
in monoculture with two size groups of fish. Aggression was assessed by recording seven
behavioural patterns: Approach and body-bending, lateral display, charge, chase, bite, frontal
display, and fight.
Aggression between fish of different size showed one step in a hierarchy where larger fish were
most aggressive in all species. Most aggression occurred between fish of similar size.
Atlantic salmon most frequently showed charge, bites and intention movements. Sea trout
showed most of intention movements and frontal display. Rainbow trout performed charge and
bite most frequently, and intention movements and chasing secondly. Body-bending was
typically performed by rainbow trout, and this pattern was often intentionnally showed in
advance of charge. Arctic charr performed charge, bite and chase at a similar frequency. | en |
