Meeting Abstract
All life acquires energy through metabolic processes, and then that energy is allocated to survival, growth, and reproduction. Thus, metabolic rate is thought to be closely related to life-history traits as it governs how energy is allocated among competing functions. Previous work suggests that life-history traits, such as somatic and population growth rate may explain some of the variation in the relationship of basal metabolic rate and body mass in endotherms. However, few studies have examined the relationship of metabolic rate and life-history traits in ectotherms. Here, we ask whether life history explains variation in metabolic rate. Specifically, we examined whether somatic growth rate, age at maturity, maximum size, and population growth rate were related to metabolic rate in 100 bony and 25 cartilaginous fish species while accounting for phylogenetic non-independence. Somatic growth rate and maximum size, and population growth rate were positively related to metabolic rate, while age at maturity was negatively related. Together, these traits explain significant variation in metabolic rate. Further, metabolic rate has strong phylogenetic signal, indicating that closely related species have more similar metabolic rates than more distantly related species. Understanding the physiological basis of life-history traits, which are difficult to estimate for data-poor and threatened species, has the potential to improve conservation and management efforts as life histories and especially population growth rates are closely correlated to extinction risk.
