Behavioral syndromes in salmonid fish: Ecological and evolutionary implications

Ane Skjelfjord

This project focuses on individual variation in the physiological response to stress, and how such variation is related to behavior. Stress sensitivity has been correlated to a number of major axes of variation in behavior, including activity, shyness-boldness, and aggression. This phenomenon has been termed behavioral syndromes, and may have several important ecological and evolutionary implications.

Project leader: Morten Bakken
Post doc: Øyvind Øverli

Project goals
One of the questions to be addressed is how variation in correlated traits is maintained in a population. We aim to address the occurrence and fitness consequences of behavioral syndromes in two salmonid fish model systems:
• Genetically selected rainbow trout lines expressing correlated differences in behavior and physiology, and
• wild lake-migratory brown trout from a river system where migratory behavior, density and growth differ between two nearby stream sections.

Behavior and performance of fish with these backgrounds will be compared under both laboratory conditions designed to identify individual profiles in salmonid fish, and in semi-natural artificial streams. The latter part of the project is carried out in cooperation with professor Larry Greenberg at Karlstad University, Sweden.

Behavioral syndromes in wild-type salmonid populations
Fish with consistently low cortisol concentrations under stress are characterized by enhanced competitiveness and a strong tendency to become socially dominant, a more rapid recovery of food intake after transfer to a novel environment, and a reduced panic response under acute stress. We aim to verify that these trait associations represent selection for behavioral syndromes that are also present in wild-type salmonid populations. We will also study whether the frequency distribution of different behavioral syndromes differ between brown trout populations from two nearby localities that appear to incur different selective pressures. Thereafter we will investigate whether different behavioral syndromes are associated with altered fitness in fluctuating vs stable environments.

Forskdok key words: fish, trout, stress, behaviour, cortisol, migration

Forskdok emneord: fisk, ørret, stress, atferd, adferd, kortisol, migrasjon

Oppdatert: 06.03.06
Utskriftsvennlig versjon : Arkiv : Tips en venn