This paper quantifies the relationship between respiratory allocation (air vs. water) and the standard rate of metabolism (SMR) in the primitive air-breathing lungfish, Protopterus aethiopicus. Simultaneous measurements of oxygen consumed from both air and water were made to determine the SMR at ecologically relevant aquatic oxygen levels for juveniles 2 to 221 g. Total metabolic rate was positively correlated with body mass with a scaling exponent of 0.78. Aerial oxygen consumption averaged 98% (range = 94% to 100%) of total respiratory allocation under low aquatic oxygen levels. Measurements of oxygen consumption made across a gradient of dissolved oxygen from normoxia to anoxia showed that P. aethiopicus maintains its SMR despite a change in respiratory allocation between water and air.
|Number of pages||7|
|Journal||Comparative Biochemistry and Physiology - A Molecular and Integrative Physiology|
|State||Published - Jan 2006|
Bibliographical noteFunding Information:
Funding for this research was provided from the University of Florida, the National Science Foundation (IBN-0094393), the Wildlife Conservation Society, the Raney Fund, and Sigma Xi. Permission to conduct research in Uganda was acquired from the National Council for Science and Technology, the Office of the President, and Makerere University (Uganda). We thank the graduate students and field assistants at Lake Nabugabo for assistance with various aspects of this project. We also thank Frank Nordlie, Stephen Walsh, and Patrick Walsh for comments on an earlier version of this manuscript. Our experimental protocols for P. aethiopicus were approved by the University of Florida (IACUC project #Z090).
- Air breathing
- Oxygen consumption
ASJC Scopus subject areas
- Molecular Biology