Growing through predation windows:: effects on body size development in young fish
2010 (English)In: Oikos, ISSN 0030-1299, E-ISSN 1600-0706, Vol. 119, 1796-1804 p.Article in journal (Refereed) Published
Th e degree to which growth in early life stages of animals is regulated via density-dependent feedbacks through preyresources is much debated. Here we have studied the infl uence of size- and density-dependent mechanisms as well as sizeselectivepredation pressure by cannibalistic perch Perca fl uviatilis on growth patterns of young-of-the-year (YOY) perchcovering several lakes and years. We found no infl uence of initial size or temperature on early body size development ofperch. In contrast, there was a negative relationship between reproductive output and the length of YOY perch at fi ve weeksof age. However, rather than an eff ect of density-dependent growth mediated via depressed resources the relationship wasdriven by positive size-selective cannibalism removing large individuals. Hence, given a positive correlation between thedensity of victims and predation pressure by cannibals, size-dependent interactions between cannibals and their victimsmay wrongly be interpreted as patterns of density-dependent growth in the victim cohort. Overall, our results support theview that density-dependent resource-limitation in early life stages is rare. Still, patterns of density-dependent growth mayemerge, but from variation in size-selective predation pressure rather than density as such. Th is illustrates the importanceof taking overall population demography and predatory interactions into account when studying growth patterns amongrecruiting individuals.
Place, publisher, year, edition, pages
2010. Vol. 119, 1796-1804 p.
Research subject Animal Ecology; Limnology
IdentifiersURN: urn:nbn:se:umu:diva-25767DOI: 10.1111/j.1600-0706.2010.18475.xISI: 000283165700008OAI: oai:DiVA.org:umu-25767DiVA: diva2:233726