Abstract

Many studies have documented that hatchery-reared salmonids generally have inferior survival after being stocked compared with wild conspecifics, hatchery and wild salmonids have been observed to differ in their antipredator responses. The response of brown trout (Salmo trutta) juveniles (0+) of differing backgrounds to a live predator was compared in two experiments. First, the antipredator behaviour of predator-naive hatchery-reared brown trout and wild-exposed brown trout were assessed in behavioural trials which lasted for eightdays. Second, predator-naive and predator-conditioned hatchery-reared brown trout were assessed in identical behavioural trials. Brown trout were predator-conditioned' by being held in a stream-water aquarium with adult Atlantic salmon (Salmo salar) and adult brown trout for twodays prior to behavioural trials. Predator-conditioned hatchery-reared brown trout spent more time in shelters in the trial aquaria than predator-naive hatchery-reared fish, but did not differ in time spent in the predator-free area. Predator conditioning may account for the increased time spent in the shelter, but does not appear to have affected time spent in the predator-free area. However, even if significant alteration in behaviour can be noted in the laboratory, the response might not be appropriate in the wild.

Keywords

Salmo trutta; brown trout; predator avoidance; learning; hatchery

Published in

Ecology of Freshwater Fish
2015, Volume: 24, number: 3, pages: 329-337

SLU Authors

• Petersson, Erik

  • Department of Aquatic Resources (SLU Aqua), Swedish University of Agricultural Sciences
    

• Järvi, Torbjörn

  • Department of Aquatic Resources (SLU Aqua), Swedish University of Agricultural Sciences
    

Associated SLU-program

Lakes and watercourses


UKÄ Subject classification

Behavioral Sciences Biology


Publication identifier

DOI: https://doi.org/10.1111/eff.12146

Permanent link to this page (URI)

https://res.slu.se/id/publ/92108