Ontogenetic comparisons of standard metabolism in three species of crocodilians

C M Gienger; Matthew L Brien; Christopher R Tracy; S Charlie Manolis; Grahame J W Webb; Roger S Seymour; Keith A Christian

doi:10.1371/journal.pone.0171082

Ontogenetic comparisons of standard metabolism in three species of crocodilians

PLoS One. 2017 Feb 9;12(2):e0171082. doi: 10.1371/journal.pone.0171082. eCollection 2017.

Authors

C M Gienger¹, Matthew L Brien^{1

2}, Christopher R Tracy¹, S Charlie Manolis², Grahame J W Webb^{1

2}, Roger S Seymour³, Keith A Christian¹

Affiliations

¹ Research Institute for the Environment and Livelihoods, Charles Darwin University, Darwin, Northern Territory, Australia.
² Wildlife Management International and Crocodylus Park, Berrimah, Northern Territory, Australia.
³ School of Earth and Environmental Sciences, University of Adelaide, Adelaide, South Australia, Australia.

Abstract

Due in part to their large size, aggressive temperament, and difficulty in handling, there are few physiological studies of adult crocodilians in the literature. As a result, studies comparing individuals across an ontogenetic series and comparisons among species are also lacking. We addressed this gap in knowledge by measuring standard metabolic rates (SMR) of three species of crocodilians (Crocodylus porosus, C. johnsoni, and Alligator mississippiensis), and included individuals that ranged from 0.22 to 114 kg. Allometric scaling of SMR with body mass was similar among the species, but C. porosus had significantly higher SMR than did C. johnsoni or A. mississippiensis. Differences in SMR among species are potentially related to behavioural differences in levels of aggression; C. porosus are the most aggressive of the crocodilians measured, and have rates of standard metabolism that are approximately 36% higher at the grand mean body size than those measured for C. johnsoni or A. mississippiensis, which are among the least aggressive crocodilians.

MeSH terms

Aggression
Alligators and Crocodiles / classification
Alligators and Crocodiles / metabolism*
Alligators and Crocodiles / physiology
Animals
Basal Metabolism*
Behavior, Animal
Body Weight

Grants and funding

Support was provided by the Australian Research Council (www.arc.gov.edu; Linkage Grant LP0882478), the Rural Industries Research and Development Corporation (www.rirdc.gov.au; Project PRJ-000660), the Northern Territory Research and Innovation Fund, and Wildlife Management International (www.wmi.com.au).