Abstract
Few fast-swimming apex fishes are classified as ‘regional endotherms’, having evolved a relatively uncommon suite of traits (e.g. elevated body temperatures, centralised red muscle, and thick-walled hearts) thought to facilitate a fast, predatory lifestyle. Unlike those apex predators, Endangered basking sharks Cetorhinus maximus are massive filter-feeding planktivores assumed to have the anatomy and physiology typical of fully ectothermic fishes. We combined dissections of stranded specimens with biologging of free-swimming individuals and found that basking sharks have red muscle located medially at the trunk, almost 50% compact myo - cardium of the ventricle, and subcutaneous white muscle temperatures consistently 1.0 to 1.5°C above ambient. Collectively, our findings suggest basking sharks are not full ectotherms, instead sharing several traits used to define a regional endotherm, thus deviating from our current understanding of the species and questioning the link between physiology and ecology of regionally endothermic shark species. With successful forecasting of population dynamics and distribution shifts often improved by accurate physiological data, our results may help explain movement patterns of the species, which could ultimately facilitate conservation efforts.
Original language | English |
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Pages (from-to) | 227-232 |
Number of pages | 6 |
Journal | Endangered Species Research |
Volume | 51 |
DOIs | |
Publication status | Published - 20 Jul 2023 |
Bibliographical note
Funding Information:Acknowledgments. We thank S. Berrow, P. Whooley, and J. Barnett for arranging access to basking shark strandings, N. Phillips, L. Eagling, L. Harding, and M. Dean for assisting with sample collection and storage, D. Edwards for skippering the boat, and S. Battaglioli for creating the 3-dimensional model basking shark. H.R.D. was funded by the Irish Research Council (GOIPG/2019/4197) and partly funded by the Fisheries Society for the British Isles (FSBI-GR21-101), A.L.J. was funded by the Irish Research Council grant IRCLA/ 2017/186 and N.L.P. was supported by Science Foundation Ireland (18/SIRG/5549). Fieldwork was conducted under license and under the aegis of the UK Cetacean Strandings Investigation Programme, which is co-funded by Defra and the Devolved Governments of Scotland and Wales (ME6008) and biologging deployment was conducted under license from the Health Products Regulatory Authority of Ireland (AE19136/P127).
Funding Information:
We thank S. Berrow, P. Whooley, and J. Barnett for arranging access to basking shark strandings, N. Phillips, L. Eagling, L. Harding, and M. Dean for assisting with sample collection and storage, D. Edwards for skippering the boat, and S. Battaglioli for creating the 3-dimensional model basking shark. H.R.D. was funded by the Irish Research Council (GOIPG/2019/4197) and partly funded by the Fisheries Society for the British Isles (FSBI-GR21-101), A.L.J. was funded by the Irish Research Council grant IRCLA/ 2017/186 and N.L.P. was supported by Science Foundation Ireland (18/SIRG/5549). Fieldwork was conducted under license and under the aegis of the UK Cetacean Strandings Investigation Programme, which is co-funded by Defra and the Devolved Governments of Scotland and Wales (ME6008) and biologging deployment was conducted under license from the Health Products Regulatory Authority of Ireland (AE19136/P127)
Publisher Copyright:
© The authors 2023. Open Access under Creative Commons by Attribution Licence. Use, distribution and reproduction are un - restricted. Authors and original publication must be credited.
Keywords
- Anatomy
- Biologging
- Ectotherm
- Physiology
- Regional endothermy
ASJC Scopus subject areas
- Ecology
- Nature and Landscape Conservation