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Temperature and diet effects on omnivorous fish performance: Implications for the latitudinal diversity gradient in herbivorous fishes

Canadian Journal of Fisheries and Aquatic Sciences

By:
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DOI: 10.1139/F07-063

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Abstract

Herbivorous fishes show a clear latitudinal diversity gradient, making up a larger proportion of the fish species in a community in tropical waters than in temperate waters. One proposed mechanism that could drive this gradient is a physiological constraint due to temperature. One prediction based on this mechanism is that if herbivorous fishes could shift their diet to animal material, they would be better able to grow, survive, and reproduce in cold waters. We tested this prediction on the omnivore Girella nigricans under different temperature and diet regimes using RNA-DNA ratios as an indicator of performance. Fish had increased performance (100%) at low temperatures (12??C) when their diet was supplemented with animal material. In contrast, at higher temperatures (17, 22, and 27??C) fish showed no differences between diets. This indicates that omnivorous fishes could increase their performance at low temperatures by consuming more animal matter. This study supports the hypothesis that a relative increase in the nutritional value of plant material at warmer temperatures could drive the latitudinal diversity gradient in herbivorous fishes. ?? 2007 NRC.

Additional Publication Details

Publication type:
Article
Publication Subtype:
Journal Article
Title:
Temperature and diet effects on omnivorous fish performance: Implications for the latitudinal diversity gradient in herbivorous fishes
Series title:
Canadian Journal of Fisheries and Aquatic Sciences
DOI:
10.1139/F07-063
Volume
64
Issue:
6
Year Published:
2007
Language:
English
Larger Work Type:
Article
Larger Work Subtype:
Journal Article
First page:
867
Last page:
873
Number of Pages:
7