Body size distributions in North American freshwater fish: small-scale factors and synthesis
Article first published online: 1 JAN 2013
© 2013 John Wiley & Sons A/S
Ecology of Freshwater Fish
Volume 22, Issue 2, pages 257–267, April 2013
How to Cite
2012. © 2012 The Authors. Journal Compilation © 2012 Blackwell MunksgaardBody size distributions in North American freshwater fish: small-scale factors and synthesis.Ecology of Freshwater Fish.
- Issue published online: 14 MAR 2013
- Article first published online: 1 JAN 2013
- Manuscript Accepted: 26 NOV 2012
- ecosystem size;
- trophic structure;
The ecosystem size/trophic structure hypothesis predicts that the shape of body size distributions will change with ecosystem size because of increases in the relative importance of large, predatory, species. I test the hypothesis by examining the statistical moments, as measures of shape, of species body size distributions of North American freshwater fish assemblages in lakes. Species lists, coupled with dietary and body size information, are used to document the patterns. Body size distributions in small lakes are unimodal and right-skewed, but distributions become more symmetrical and bimodal in large ecosystems. In small lakes, body sizes are generally small and fish trophic levels low, but size and trophic level increase up to lake volumes of about 0.001 km3, and change little in larger lakes. Adding trophic level to the analysis greatly improves the variance explained by the body size–lake size relation. The conclusions of Griffiths (2012, Global Ecology & Biogeography 21: 383-392), that postglacial recolonisation and evolutionary change are important determinants of body size distributions at regional and larger scales, are combined with those of this study. Mean body size in local assemblages of lake-dwelling species is larger than in regional and continental ones. Overall, body size distributions are affected by processes operating at a variety of spatial and temporal scales, with the type, size and duration of the ecosystem probably playing a central role by influencing the proportions of vagile and predatory species, the species which dominate the large size mode.