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Oxygen Consumption of Desert Pupfish at Ecologically‐Relevant Temperatures Suggests a Significant Role for Anaerobic Metabolism
Author(s) -
Hillyard Stanley,
Breukelen Frank
Publication year - 2017
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.31.1_supplement.874.3
Subject(s) - anaerobic exercise , acclimatization , biology , oxygen , fish <actinopterygii> , population , ecology , zoology , vo2 max , fishery , chemistry , physiology , heart rate , demography , organic chemistry , sociology , blood pressure , endocrinology
Oxygen consumption is oftentimes used as a proxy for metabolic rate. Routine oxygen consumption (R VO2 ) of a refuge population of Cyprinodon diabolis acclimated to ecologically relevant temperatures of 28 °C and 33 °C was evaluated at assay temperatures between 25 °C and 38 °C. Different interpretations of the data are available depending on normalization. For instance, R VO2 of smaller fish, measured per fish, was remarkably stable over a wide range of assay temperatures and was not different between acclimation groups. Measured on a mass‐specific basis, R VO2 in larger fish increased more predictably as temperature increased. R VO2 of refuge fish and the closely related pupfish, C. nevadensis mionectes , measured near their respective acclimation temperatures of either 28 °C or 33 °C were essentially identical. However, R VO2 of 28 °C acclimated fish of both species, when measured at 33 °C, was greater than that of the 33 °C acclimated fish measured at 28 °C. We suggest this observed ‘efficiency’ may result from significant anaerobic metabolism use. Experiments investigating metabolic scope (Max VO2 /R VO2 ) yielded values less than 1 in 33 °C acclimated fish. These values indicate a substantial contribution of anaerobic metabolism to energy utilization by these fish. However, muscle lactate levels are not elevated in exercising fish‐ a result that is consistent with paradoxical anaerobism use. Support or Funding Information Supported by grants from the US Fish and Wildlife Service and Nevada Department of Wildlife