Maximum cardiac performance of Antarctic fishes that lack haemoglobin and myoglobin: exploring the effect of warming on nature’s natural knockouts
Abstract Antarctic notothenioids, some of which lack myoglobin (Mb) and/or haemoglobin (Hb), are considered extremely stenothermal, which raises conservation concerns since Polar regions are warming at unprecedented rates. Without reliable estimates of maximum cardiac output ($\dot{Q}$), it is impos...
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2019
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Online Access: | http://dx.doi.org/10.1093/conphys/coz049 http://academic.oup.com/conphys/article-pdf/7/1/coz049/30133082/coz049.pdf |
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croxfordunivpr:10.1093/conphys/coz049 2024-04-28T07:58:27+00:00 Maximum cardiac performance of Antarctic fishes that lack haemoglobin and myoglobin: exploring the effect of warming on nature’s natural knockouts Egginton, Stuart Axelsson, Michael Crockett, Elizabeth L O’Brien, Kristin M Farrell, Anthony P Todgham, Anne NSERC Canada Swedish Research Council University of Leeds Natural Sciences and Engineering Council of Canada National Science Foundation 2019 http://dx.doi.org/10.1093/conphys/coz049 http://academic.oup.com/conphys/article-pdf/7/1/coz049/30133082/coz049.pdf en eng Oxford University Press (OUP) http://creativecommons.org/licenses/by/4.0/ Conservation Physiology volume 7, issue 1 ISSN 2051-1434 Management, Monitoring, Policy and Law Nature and Landscape Conservation Ecological Modeling Physiology journal-article 2019 croxfordunivpr https://doi.org/10.1093/conphys/coz049 2024-04-02T08:04:44Z Abstract Antarctic notothenioids, some of which lack myoglobin (Mb) and/or haemoglobin (Hb), are considered extremely stenothermal, which raises conservation concerns since Polar regions are warming at unprecedented rates. Without reliable estimates of maximum cardiac output ($\dot{Q}$), it is impossible to assess their physiological scope in response to warming seas. Therefore, we compared cardiac performance of two icefish species, Chionodraco rastrospinosus (Hb−Mb+) and Chaenocephalus aceratus (Hb−Mb−), with a related notothenioid, Notothenia coriiceps (Hb+Mb+) using an in situ perfused heart preparation. The maximum $\dot{Q}$, heart rate (fH), maximum cardiac work (WC) and relative ventricular mass of N. coriiceps at 1°C were comparable to temperate-water teleosts, and acute warming to 4°C increased fH and WC, as expected. In contrast, icefish hearts accommodated a higher maximum stroke volume (VS) and maximum $\dot{Q}$ at 1°C, but their unusually large hearts had a lower fH and maximum afterload tolerance than N. coriiceps at 1°C. Furthermore, maximum VS, maximum $\dot{Q}$ and fH were all significantly higher for the Hb−Mb+ condition compared with the Hb−Mb− condition, a potential selective advantage when coping with environmental warming. Like N. coriiceps, both icefish species increased fH at 4°C. Acutely warming C. aceratus increased maximum $\dot{Q}$, while C. rastrospinosus (like N. coriiceps) held at 4°C for 1 week maintained maximum $\dot{Q}$ when tested at 4°C. These experiments involving short-term warming should be followed up with long-term acclimation studies, since the maximum cardiac performance of these three Antarctic species studied seem to be tolerant of temperatures in excess of predictions associated with global warming. Article in Journal/Newspaper Antarc* Antarctic Icefish Oxford University Press Conservation Physiology 7 1 |
institution |
Open Polar |
collection |
Oxford University Press |
op_collection_id |
croxfordunivpr |
language |
English |
topic |
Management, Monitoring, Policy and Law Nature and Landscape Conservation Ecological Modeling Physiology |
spellingShingle |
Management, Monitoring, Policy and Law Nature and Landscape Conservation Ecological Modeling Physiology Egginton, Stuart Axelsson, Michael Crockett, Elizabeth L O’Brien, Kristin M Farrell, Anthony P Maximum cardiac performance of Antarctic fishes that lack haemoglobin and myoglobin: exploring the effect of warming on nature’s natural knockouts |
topic_facet |
Management, Monitoring, Policy and Law Nature and Landscape Conservation Ecological Modeling Physiology |
description |
Abstract Antarctic notothenioids, some of which lack myoglobin (Mb) and/or haemoglobin (Hb), are considered extremely stenothermal, which raises conservation concerns since Polar regions are warming at unprecedented rates. Without reliable estimates of maximum cardiac output ($\dot{Q}$), it is impossible to assess their physiological scope in response to warming seas. Therefore, we compared cardiac performance of two icefish species, Chionodraco rastrospinosus (Hb−Mb+) and Chaenocephalus aceratus (Hb−Mb−), with a related notothenioid, Notothenia coriiceps (Hb+Mb+) using an in situ perfused heart preparation. The maximum $\dot{Q}$, heart rate (fH), maximum cardiac work (WC) and relative ventricular mass of N. coriiceps at 1°C were comparable to temperate-water teleosts, and acute warming to 4°C increased fH and WC, as expected. In contrast, icefish hearts accommodated a higher maximum stroke volume (VS) and maximum $\dot{Q}$ at 1°C, but their unusually large hearts had a lower fH and maximum afterload tolerance than N. coriiceps at 1°C. Furthermore, maximum VS, maximum $\dot{Q}$ and fH were all significantly higher for the Hb−Mb+ condition compared with the Hb−Mb− condition, a potential selective advantage when coping with environmental warming. Like N. coriiceps, both icefish species increased fH at 4°C. Acutely warming C. aceratus increased maximum $\dot{Q}$, while C. rastrospinosus (like N. coriiceps) held at 4°C for 1 week maintained maximum $\dot{Q}$ when tested at 4°C. These experiments involving short-term warming should be followed up with long-term acclimation studies, since the maximum cardiac performance of these three Antarctic species studied seem to be tolerant of temperatures in excess of predictions associated with global warming. |
author2 |
Todgham, Anne NSERC Canada Swedish Research Council University of Leeds Natural Sciences and Engineering Council of Canada National Science Foundation |
format |
Article in Journal/Newspaper |
author |
Egginton, Stuart Axelsson, Michael Crockett, Elizabeth L O’Brien, Kristin M Farrell, Anthony P |
author_facet |
Egginton, Stuart Axelsson, Michael Crockett, Elizabeth L O’Brien, Kristin M Farrell, Anthony P |
author_sort |
Egginton, Stuart |
title |
Maximum cardiac performance of Antarctic fishes that lack haemoglobin and myoglobin: exploring the effect of warming on nature’s natural knockouts |
title_short |
Maximum cardiac performance of Antarctic fishes that lack haemoglobin and myoglobin: exploring the effect of warming on nature’s natural knockouts |
title_full |
Maximum cardiac performance of Antarctic fishes that lack haemoglobin and myoglobin: exploring the effect of warming on nature’s natural knockouts |
title_fullStr |
Maximum cardiac performance of Antarctic fishes that lack haemoglobin and myoglobin: exploring the effect of warming on nature’s natural knockouts |
title_full_unstemmed |
Maximum cardiac performance of Antarctic fishes that lack haemoglobin and myoglobin: exploring the effect of warming on nature’s natural knockouts |
title_sort |
maximum cardiac performance of antarctic fishes that lack haemoglobin and myoglobin: exploring the effect of warming on nature’s natural knockouts |
publisher |
Oxford University Press (OUP) |
publishDate |
2019 |
url |
http://dx.doi.org/10.1093/conphys/coz049 http://academic.oup.com/conphys/article-pdf/7/1/coz049/30133082/coz049.pdf |
genre |
Antarc* Antarctic Icefish |
genre_facet |
Antarc* Antarctic Icefish |
op_source |
Conservation Physiology volume 7, issue 1 ISSN 2051-1434 |
op_rights |
http://creativecommons.org/licenses/by/4.0/ |
op_doi |
https://doi.org/10.1093/conphys/coz049 |
container_title |
Conservation Physiology |
container_volume |
7 |
container_issue |
1 |
_version_ |
1797569566955536384 |