title: Scaling of standard metabolic rate in estuarine crocodiles Crocodylus porosus.
abstract: Standard metabolic rate (SMR, ml O2 min(-1)) of captive Crocodylus porosus at 30 °C scales with body mass (kg) according to the equation, SMR = 1.01 M(0.829), in animals ranging in body mass of 3.3 orders of magnitude (0.19-389 kg). The exponent is significantly higher than 0.75, so does not conform to quarter-power scaling theory, but rather is likely an emergent property with no single explanation. SMR at 1 kg body mass is similar to the literature for C. porosus and for alligators. The high exponent is not related to feeding, growth, or obesity of captive animals. The log-transformed data appear slightly curved, mainly because SMR is somewhat low in many of the largest animals (291-389 kg). A 3-parameter model is scarcely different from the linear one, but reveals a declining exponent between 0.862 and 0.798. A non-linear model on arithmetic axes overestimates SMR in 70% of the smallest animals and does not satisfactorily represent the data.
authors.affiliation: School of Earth and Environmental Sciences, University of Adelaide, Adelaide, SA 5005, Australia. roger.seymour@adelaide.edu.au
authors.forename: Roger S
authors.initials: RS
authors.lastname: Seymour
authors.forename: C M
authors.initials: CM
authors.lastname: Gienger
authors.forename: Matthew L
authors.initials: ML
authors.lastname: Brien
authors.forename: Christopher R
authors.initials: CR
authors.lastname: Tracy
authors.forename: S
authors.initials: S
authors.lastname: Charlie Manolis
authors.forename: Grahame J W
authors.initials: GJ
authors.lastname: Webb
authors.forename: Keith A
authors.initials: KA
authors.lastname: Christian
mesh_terms: D000489:Alligators and Crocodiles / Q000502:physiology*; D000818:Animals; D001481:Basal Metabolism; D049628:Body Size; D001835:Body Weight; D008954:Models, Biological; D010100:Oxygen / Q000378:metabolism; D012044:Regression Analysis
chemical_list: D010100:Oxygen