The relationship between temperature and standard rate of metabolism in African lungfish, <i>Protopterus aethiopicus</i>, from Uganda

Abstract

The relationship between temperature and metabolism among ancient (non-teleost) fishes, while largely unknown, is essential to an understanding of the effects of temperature on fish energetics. This study quantifies the effect of temperature on the standard rate of metabolism in the African lungfish, Protopterus aethiopicus. We present a Q₁₀ value of 3.3 for individuals ranging in body mass from 42–222g across an ecologically-relevant 10°C temperature range. Protopterus aethiopicus showed a positive bilogarithmic (log-log) relationship between the rate of oxygen consumption and body mass (range = 44–222g) at three water temperatures (20, 25, 30°C). However, adjusted mean rates of oxygen consumption differed among all three temperatures. A Q₁₀ value derived as the means of Q₁₀ values calculated for each individual lungfish averaged 3.3 ± 0.4 (SE) for 20–30°C. A comparison of literature-derived Q₁₀ values for both tropical and temperate fishes suggests a higher Q₁₀ in tropical species (n = 3) than in temperate species (n = 10) across an ecologically-relevant thermal range.

Keywords: air-breathing fish, ecophysiology, metabolic rate, Q₁₀, respirometry

African Journal of Aquatic Science 2007, 32(3): 299–303