Niche expansion of the shorthorn sculpin (Myoxocephalus scorpius) to Arctic waters is supported by a thermal independence of cardiac performance at low temperature
2013 (English)In: Canadian Journal of Zoology, ISSN 0008-4301, E-ISSN 1480-3283, Vol. 91, no 8, 573-580 p.Article in journal (Refereed) Published
Cardiovascular adaptations that permit successful exploitation of polar marine waters by fish requires a capacity tonegate or compensate for the depressive effects of low temperatures on physiological processes. Here, we examined the effectsof acute and chronic temperature change on the maximum cardiac performance of shorthorn sculpin (Myoxocephalusscorpius (L., 1758)) captured above the Arctic Circle. Our aim was to establish if the sculpin’s success at low temperatures wasachieved through thermal independence of cardiac function or via thermal compensation as a result of acclimation. Maximumcardiac performance was assessed at both 1 and 6 °C with a working perfused heart preparation that was obtained after fish hadbeen acclimated to either 1 or 6 °C. Thus, tests were performed at the fish’s acclimation temperature and with an acutetemperature change. Maximum cardiac output, which was relatively large (>50 mL·min−1·kg−1 body mass) for a benthic fish at afrigid temperature, was found to be independent of both acclimation temperature and test temperature. While maximum-adrenergic stimulation produced positive chronotropy at both acclimation temperatures, inotropic effects were weak orabsent. We conclude that thermal independence of cardiac performance at low temperature likely facilitated the exploitation ofpolar waters by the shorthorn sculpin.
Place, publisher, year, edition, pages
NRC Research Press, 2013. Vol. 91, no 8, 573-580 p.
Myoxocephalus scorpius, perfused heart, cardiac output, adrenaline, power generation, pressure.
IdentifiersURN: urn:nbn:se:liu:diva-97616DOI: 10.1139/cjz-2013-0038ISI: 000324683000005OAI: oai:DiVA.org:liu-97616DiVA: diva2:649363