EconPapers    
Economics at your fingertips  
 

Thermal optima in the hypoxia tolerance of marine ectotherms: Physiological causes and biogeographic consequences

Martin-Georg A Endress, Justin L Penn, Thomas H Boag, Benjamin P Burford, Erik A Sperling and Curtis A Deutsch

PLOS Biology, 2024, vol. 22, issue 1, 1-17

Abstract: The minimum O2 needed to fuel the demand of aquatic animals is commonly observed to increase with temperature, driven by accelerating metabolism. However, recent measurements of critical O2 thresholds (“Pcrit”) reveal more complex patterns, including those with a minimum at an intermediate thermal “optimum”. To discern the prevalence, physiological drivers, and biogeographic manifestations of such curves, we analyze new experimental and biogeographic data using a general dynamic model of aquatic water breathers. The model simulates the transfer of oxygen from ambient water through a boundary layer and into animal tissues driven by temperature-dependent rates of metabolism, diffusive gas exchange, and ventilatory and circulatory systems with O2-protein binding. We find that a thermal optimum in Pcrit can arise even when all physiological rates increase steadily with temperature. This occurs when O2 supply at low temperatures is limited by a process that is more temperature sensitive than metabolism, but becomes limited by a less sensitive process at warmer temperatures. Analysis of published species respiratory traits suggests that this scenario is not uncommon in marine biota, with ventilation and circulation limiting supply under cold conditions and diffusion limiting supply at high temperatures. Using occurrence data, we show that species with these physiological traits inhabit lowest O2 waters near the optimal temperature for hypoxia tolerance and are restricted to higher O2 at temperatures above and below this optimum. Our results imply that hypoxia tolerance can decline under both cold and warm conditions and thus may influence both poleward and equatorward species range limits.The minimum oxygen level needed to fuel the demand of aquatic animals is commonly observed to increase with temperature, driven by accelerating metabolism. However, this study uses species measurements and a dynamical model to reveal how oxygen supply can reduce hypoxia tolerance and limit biogeographic ranges of marine ectotherms under both cold and warm conditions.

Date: 2024
References: View references in EconPapers View complete reference list from CitEc
Citations:

Downloads: (external link)
https://journals.plos.org/plosbiology/article?id=10.1371/journal.pbio.3002443 (text/html)
https://journals.plos.org/plosbiology/article/file ... 02443&type=printable (application/pdf)

Related works:
This item may be available elsewhere in EconPapers: Search for items with the same title.

Export reference: BibTeX RIS (EndNote, ProCite, RefMan) HTML/Text

Persistent link: https://EconPapers.repec.org/RePEc:plo:pbio00:3002443

DOI: 10.1371/journal.pbio.3002443

Access Statistics for this article

More articles in PLOS Biology from Public Library of Science
Bibliographic data for series maintained by plosbiology ().

 
Page updated 2025-05-31
Handle: RePEc:plo:pbio00:3002443