Allometric scaling of lung volume and its consequences for marine turtle diving performance
Date
2007
Authors
Hochscheid, S.
McMahon, C.
Bradshaw, C.
Maffucci, F.
Bentivegna, F.
Hays, G.
Editors
Advisors
Journal Title
Journal ISSN
Volume Title
Type:
Journal article
Citation
Comparative Biochemistry and Physiology -Part A : Molecular and Integrative Physiology, 2007; 148(2):360-367
Statement of Responsibility
Sandra Hochscheid, Clive R. McMahon, Corey J.A. Bradshaw, Fulvio Maffucci, Flegra Bentivegna and Graeme C. Hays
Conference Name
Abstract
Marine turtle lungs have multiple functions including respiration, oxygen storage and buoyancy regulation, so lung size is an important indicator of dive performance. We determined maximum lung volumes (VL) for 30 individuals from three species (Caretta caretta n = 13; Eretmochelys imbricata n = 12; Natator depressus n = 5) across a range of body masses (Mb): 0.9 to 46 kg. VL was 114 ml kg−1 and increased with Mb with a scaling factor of 0.92. Based on these values for VL we demonstrated that diving capacities (assessed via aerobic dive limits) of marine turtles were potentially over-estimated when the VL-body mass effect was not considered (by 10 to 20% for 5 to 25 kg turtles and by > 20% for turtles ≥ 25 kg). While aerobic dive limits scale with an exponent of 0.6, an analysis of average dive durations in free-ranging chelonian marine turtles revealed that dive duration increases with a mass exponent of 0.51, although there was considerable scatter around the regression line. While this highlights the need to determine more parameters that affect the duration-body mass relationship, our results provide a reference point for calculating oxygen storage capacities and air volumes available for buoyancy control.