Oxygen consumption in weakly electric Neotropical fishes

摘要: Weakly electric gymnotiform fishes with wave-type organ discharge (EOD) are less hypoxia-tolerant and likely to be found in hypoxic habitats than weakly gymnotiforms pulse-type EOD, suggesting that differences metabolism resulting from EOD type affects habitat choice. Although common most Neotropical freshwaters represent the dominant vertebrates some habitats, metabolic rates of these unique have never been determined. In this study, O2 consumption during generation reported for 34 representing 23 species, all five families 17 (59%) 28 genera. Over size range sampled (0.4 g 125 g), was dependent on body mass, as expected, fitting a power function scaling exponent 0.74, but rate generally about 50% expected by extrapolation temperate teleost similar ambient temperature (26°C). not type, maintenance “scan swimming” (continuous forwards backwards swimming), which is characteristic only EODs, increased 2.83±0.49-fold (mean±SD). This suggests cost scan swimming could restrict EODs habitats.