Behavioural and heart rate responses to predation risk in wild and domesticated Atlantic salmon

• Published in: Canadian journal of fisheries and aquatic sciences Vol. 58; no. 4; pp. 788 - 794
• Main Authors: Johnsson, Jörgen I, Höjesjö, Johan, Fleming, Ian A
• Format: Journal Article
• Language: English
• Published: Ottawa, Canada NRC Research Press 01.04.2001; National Research Council of Canada; Canadian Science Publishing NRC Research Press
• Subjects: Animal aquaculture; Animal behavior; Animal productions; Biological and medical sciences; Comparative analysis; Fish; Fundamental and applied biological sciences. Psychology; Heart; Heart rate; Marine; Pisciculture; Predation; Predators; Salmo salar; Salmon; Vertebrate aquaculture; Predator prey relation; Salmonidae; Farming animal; Functional response; Salmo salar; Domestication; Artificial selection; Wild animal; Freshwater environment; Prey; Heart rate; Vertebrata; Escape behavior; Pisces; Circulatory system; Predation; Comparative study; Aquaculture
• DOI: 10.1139/f01-025
• ISSN: 0706-652X

Artificial culture may relax the selective pressures from predators, thereby altering behavioural and heart rate responses to predation risk. Culture may also impose new selection that adapts fish to confinement. Predictions from these hypotheses were tested by comparing seventh-generation farm Atlantic salmon (Salmo salar) with wild Atlantic salmon from the principal founder population of the farm strain. Wild age 1+ salmon had higher standard heart rates and showed a more pronounced flight and heart rate response to a simulated predator attack than did farmed salmon. However, wild fish were closer to the model predator at attack, which may have accentuated these differences. Both strains habituated to the threat, showing less response to the second attack than to the first. In contrast with age 1+ fish, wild age 2+ salmon had lower standard heart rates than farmed fish. Moreover, in age 2+ salmon, domestication effects were less clear and the response to predation threat considerably weaker, suggesting that environmental effects of culture override genetic effects as time in captivity increases. Domestication selection may thus alter reaction norms of farmed animals over environmental gradients and time. This should be considered when attempting to predict the consequences of release or escape of domesticated animals in the wild.