Environmental physiology of a small marsupial inhabiting arid floodplains

Title
Environmental physiology of a small marsupial inhabiting arid floodplains
Publication Date
2010
Author(s)
Warnecke, Lisa
Cooper, CE
Geiser, Fritz
( author )
OrcID: https://orcid.org/0000-0001-7621-5049
Email: fgeiser@une.edu.au
UNE Id une-id:fgeiser
Withers, Philip
Type of document
Journal Article
Language
en
Entity Type
Publication
Publisher
Elsevier Inc
Place of publication
United States of America
DOI
10.1016/j.cbpa.2010.04.018
UNE publication id
une:7699
Abstract
Giles' planigale ('Planigale gilesi') is among the smallest extant marsupials and inhabits deep soil cracks in arid floodplains. We examined whether its physiology shows specific adaptations to its extreme habitat. Metabolic rate, body temperature, evaporative water loss and thermal conductance were measured for eight planigales (average mass 9 g) exposed to four different ambient temperatures ranging from 10°C to 32°C. Water economy and respiratory variables were measured for the first time in this species. All of these standard physiological variables conformed to allometrically-predicted values for a marsupial. All variables were significantly affected by ambient temperature, except tidal volume and dry thermal conductance. Metabolic rate increased substantially at low ambient temperatures, as required to maintain a relatively constant body temperature of about 32–34°C. This increased oxygen demand was accommodated by increased ventilation rather than increased oxygen extraction. Planigales had a comparatively high point of relative water economy of 19.1°C, consistent with their small body size and arid habitat. Torpor reduced energy expenditure by 79% and evaporative water loss by 62%. Our study suggests that torpor use, along with behavioural adaptations, suffice for 'P. gilesi' to live underground in arid habitats without further physiological adaptations.
Link
Citation
Comparative Biochemistry and Physiology Part A: Molecular & Integrative Physiology, 157(1), p. 73-78
ISSN
1531-4332
1095-6433
Start page
73
End page
78

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