To the top

Page Manager: Webmaster
Last update: 9/11/2012 3:13 PM

Tell a friend about this page
Print version

Performance of wild brown… - University of Gothenburg, Sweden Till startsida
To content Read more about how we use cookies on

Performance of wild brown trout in relation to energetic state and lab-scored activity during the early-life survival bottleneck

Journal article
Authors Joacim Näslund
P. S. Claesson
Jörgen I Johnsson
Published in Behavioral Ecology and Sociobiology
Volume 71
Issue 11
ISSN 0340-5443
Publication year 2017
Published at Department of Biological and Environmental Sciences
Language en
Keywords Compensatory growth, State-dependent behavior, Salmonidae, Behavioral repeatability, Survival, pace-of-life, salmo-trutta, compensatory growth, atlantic salmon, behavioral syndromes, population regulation, territorial behavior, personality-traits, animal personality, natural-selection, Behavioral Sciences, Environmental Sciences & Ecology, Zoology
Subject categories Environmental Sciences, Behavioral Sciences Biology, Ecology, Zoology


The early life stage is typically a selective bottleneck during which individual performance is important for survival. We investigated size, energetic state, and activity, in relation to recapture probability in the youngest free-swimming stage of a territorial fish, the brown trout. In two experiments, we induced compensatory growth in wild-caught brown trout fry, using a restriction-refeeding protocol. Upon refeeding in the laboratory, the restricted trout showed compensatory growth in mass, but not in length. During this compensatory growth phase, we released the fish into their native stream habitat and then recaptured them after 1 month to assess survival and growth. Despite not having fully compensated body size at release, restricted fish did not show continued growth compensation in the stream, indicating that the natural environment limits growth capacity during early life. Individual baseline activity was scored in open-field tests before and after food restriction and was found repeatable but not significantly affected by growth manipulations. Under natural conditions, we found a positive association between open-field activity and survival (as indicated by recapture probability), but no significant differences between food-restricted and control fish. Initial body length positively influenced survival in the first experiment (early summer), but not in the second (late summer). These results contrast with the assumption that high baseline activity should be riskier in natural environments. For territorial animals, we hypothesize that activity is associated with high aggression and territoriality, which facilitates access to high-quality territories providing both shelter from predation and reduced starvation risk, which reduces mortality risk. In the early critical life stage, more active brown trout are better survivors. This finding, which contradicts general assumptions about the balance between predator exposure and food intake, could possibly be due to trout being highly territorial species in which active individuals can claim the best territories. We also find that young trout are likely limited in growth rate by environmental conditions in the wild, as growth compensation following food restriction is possible in the lab, but not realized in natural streams.

Page Manager: Webmaster|Last update: 9/11/2012

The University of Gothenburg uses cookies to provide you with the best possible user experience. By continuing on this website, you approve of our use of cookies.  What are cookies?