Intraspecific variation in thermal tolerance differs between tropical and temperate fishes

Nati, J. J. H., Svendsen, M. B. S., Marras, S., Killen, S. S. , Steffensen, J. F., McKenzie, D. J. and Domenici, P. (2021) Intraspecific variation in thermal tolerance differs between tropical and temperate fishes. Scientific Reports, 11, 21272. (doi: 10.1038/s41598-021-00695-8) (PMCID:PMC8553816)

Abstract

How ectothermic animals will cope with global warming is a critical determinant of the ecological impacts of climate change. There has been extensive study of upper thermal tolerance limits among fish species but how intraspecific variation in tolerance may be affected by habitat characteristics and evolutionary history has not been considered. Intraspecific variation is a primary determinant of species vulnerability to climate change, with implications for global patterns of impacts of ongoing warming. Using published critical thermal maximum (CTmax) data on 203 fish species, we found that intraspecific variation in upper thermal tolerance varies according to a species’ latitude and evolutionary history. Overall, tropical species show a lower intraspecific variation in thermal tolerance than temperate species. Notably, freshwater tropical species have a lower variation in tolerance than freshwater temperate species, which implies increased vulnerability to impacts of thermal stress. The extent of variation in CTmax among fish species has a strong phylogenetic signal, which may indicate a constraint on evolvability to rising temperatures in tropical fishes. That is, in addition to living closer to their upper thermal limits, tropical species may have higher sensitivity and lower adaptability to global warming compared to temperate counterparts. This is evidence that freshwater tropical fish communities, worldwide, are especially vulnerable to ongoing climate change.

• Item Type: Articles
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Killen, Professor Shaun and Nati, Miss Julie
• Authors: Nati, J. J. H., Svendsen, M. B. S., Marras, S., Killen, S. S., Steffensen, J. F., McKenzie, D. J., and Domenici, P.
• College/School: College of Medical Veterinary and Life Sciences > School of Biodiversity, One Health & Veterinary Medicine
• Journal Name: Scientific Reports
• Publisher: Nature Research
• ISSN: 2045-2322
• ISSN (Online): 2045-2322
• Copyright Holders: Copyright © 2021 The Authors
• First Published: First published in Scientific Reports 11: 21272
• Publisher Policy: Reproduced under a Creative Commons License

Project Code	Award No	Project Name	Principal Investigator	Funder's Name	Funder Ref	Lead Dept
167015		The Influence of Individual Physiology on Group Behaviour in Fish Schools	Shaun Killen	Natural Environment Research Council (NERC)	NE/J019100/1	Institute of Biodiversity, Animal Health and Comparative Medicine