Niche expansion of the shorthorn sculpin (Myoxocephalus scorpius) to Arctic waters is supported by a thermal independence of cardiac performance at low temperature
Abstract:Cardiovascular adaptations that permit successful exploitation of polar marine waters by fish requires a capacity to negate or compensate for the depressive effects of low temperatures on physiological processes. Here, we examined the effects of acute and chronic temperature change on the maximum cardiac performance of shorthorn sculpin (Myoxocephalus scorpius (L., 1758)) captured above the Arctic Circle. Our aim was to establish if the sculpin’s success at low temperatures was achieved through thermal independence of cardiac function or via thermal compensation as a result of acclimation. Maximum cardiac performance was assessed at both 1 and 6 °C with a working perfused heart preparation that was obtained after fish had been acclimated to either 1 or 6 °C. Thus, tests were performed at the fish’s acclimation temperature and with an acute temperature change. Maximum cardiac output, which was relatively large (>50 mL·min−1·kg−1 body mass) for a benthic fish at a frigid temperature, was found to be independent of both acclimation temperature and test temperature. While maximum β-adrenergic stimulation produced positive chronotropy at both acclimation temperatures, inotropic effects were weak or absent. We conclude that thermal independence of cardiac performance at low temperature likely facilitated the exploitation of polar waters by the shorthorn sculpin.
Document Type: Research Article
Affiliations: 1: Department of Zoology and Faculty of Land and Food Systems, 6270 University Boulevard, University of British Columbia, Vancouver, BC V6T 1Z4, Canada. 2: IFM Biology, Division of Zoology, University of Linköping, SE-58183 Linköping, Sweden. 3: School of Biological Sciences, The University of Queensland, Brisbane, Queensland 4072, Australia. 4: University of Gothenburg, Department of Biological and Environmental Sciences, SE-405 30 Gothenburg, Sweden.
Publication date: July 26, 2013
- Published since 1929, this monthly journal reports on primary research contributed by respected international scientists in the broad field of zoology, including behaviour, biochemistry and physiology, developmental biology, ecology, genetics, morphology and ultrastructure, parasitology and pathology, and systematics and evolution. It also invites experts to submit review articles on topics of current interest.
- Information for Authors
- Submit a Paper
- Subscribe to this Title
- Terms & Conditions
- Sample Issue
- Reprints & Permissions
- Ingenta Connect is not responsible for the content or availability of external websites