Ontogenetic comparisons of standard metabolism in three species of crocodilians.
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.
Research Institute for the Environment and Livelihoods, Charles Darwin University, Darwin, Northern Territory, Australia.
C M
http://orcid.org/0000-0001-5045-3321
CM
Gienger
Research Institute for the Environment and Livelihoods, Charles Darwin University, Darwin, Northern Territory, Australia.|Wildlife Management International and Crocodylus Park, Berrimah, Northern Territory, Australia.
Matthew L
ML
Brien
Research Institute for the Environment and Livelihoods, Charles Darwin University, Darwin, Northern Territory, Australia.
Christopher R
CR
Tracy
Wildlife Management International and Crocodylus Park, Berrimah, Northern Territory, Australia.
S Charlie
SC
Manolis
Research Institute for the Environment and Livelihoods, Charles Darwin University, Darwin, Northern Territory, Australia.|Wildlife Management International and Crocodylus Park, Berrimah, Northern Territory, Australia.
Grahame J W
GJ
Webb
School of Earth and Environmental Sciences, University of Adelaide, Adelaide, South Australia, Australia.
Roger S
RS
Seymour
Research Institute for the Environment and Livelihoods, Charles Darwin University, Darwin, Northern Territory, Australia.
Keith A
KA
Christian
D000374:Aggression; D000489:Alligators and Crocodiles / Q000145:classification / Q000378:metabolism* / Q000502:physiology; D000818:Animals; D001481:Basal Metabolism; D001522:Behavior, Animal; D001835:Body Weight