Meeting Abstract
Metabolic rate is a fundamental physiological trait that governs resource uptake and allocation, and is well known to vary with body mass and ecological lifestyle traits across species. However, previous studies have only qualitatively examined these relationships in one or a few species, most of which have been teleost fishes. Here, we quantitatively examined the relationship of metabolic rate and specific ecological lifestyle traits in a phylogenetic comparative framework. We examined how the relationship of metabolic rate and body mass varied across the ecological lifestyle traits of habitat type, activity level, and maximum body size in 26 elasmobranch species. We focussed on elasmobranchs because the large variation of ecological lifestyles among species of this group presents an ideal study system. Because metabolic rate increases ontogenetically with body mass, we also assessed the relationship between metabolic rate and ecological lifestyle in an allometric (scaling) context. Our results showed that metabolic rate for a given body mass varied across species and ecological lifestyle traits, while the rate at which metabolic rate increased with body mass remained consistent. This suggests that while metabolic rate for a given body mass is greater in larger, active, and oceanic species compared to smaller, less-active and coastal species, the rate at which metabolic rate increases ontogenetically may be driven less by ecology and more by shared evolutionary history.
