title: Respiratory allocation and standard rate of metabolism in the African lungfish, Protopterus aethiopicus.
abstract: 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.
authors.affiliation: Department of Zoology, University of Florida, Gainesville, FL 32611, USA. aseifert@zoo.ufl.edu
authors.forename: Ashley W
authors.initials: AW
authors.lastname: Seifert
authors.forename: Lauren J
authors.initials: LJ
authors.lastname: Chapman
mesh_terms: D000818:Animals; D001835:Body Weight; D004734:Energy Metabolism; D005399:Fishes / Q000502:physiology*; D005618:Fresh Water; D010101:Oxygen Consumption; D012119:Respiration