Temperature-dependent exercise recovery is not associated with behavioral thermoregulation in a salmonid fish.

Autor: Rowsey LE; Department of Biological Sciences, University of New Brunswick, Saint John, NB, Canada. Electronic address: lrowsey@unb.ca., Kieffer JD; Department of Biological Sciences, University of New Brunswick, Saint John, NB, Canada. Electronic address: jkieffer@unb.ca., Speers-Roesch B; Department of Biological Sciences, University of New Brunswick, Saint John, NB, Canada. Electronic address: bspeersr@unb.ca.
Jazyk: angličtina
Zdroj: Journal of thermal biology [J Therm Biol] 2024 Jul; Vol. 123, pp. 103888. Date of Electronic Publication: 2024 Jun 14.
DOI: 10.1016/j.jtherbio.2024.103888
Abstrakt: The relationship between behavioral thermoregulation and physiological recovery following exhaustive exercise is not well understood. Behavioral thermoregulation could be beneficial for exercise recovery; for example, selection of cooler temperatures could reduce maintenance metabolic cost to preserve aerobic scope for recovery cost, or selection of warmer temperatures could accelerate recovery of exercise metabolites. While post-exercise behavioral thermoregulation has been observed in lizards and frogs, little is known about its importance in fish. We examined the influence of post-exercise recovery temperature on metabolic rate, thermal preference, and metabolite concentrations in juvenile brook char (Salvelinus fontinalis). Fish were acclimated to and exercised at 15 °C, then recovered at either 15 °C or 10 °C while their metabolic rate was measured via respirometry. Metabolite concentrations were measured in fish after exercise at 15 °C and recovery under one of three thermal treatments (to simulate various behavioral thermoregulation scenarios): (i) 6 h recovery at 15 °C, (ii) 6 h recovery at 10 °C, or (iii) 3 h recovery at 10 °C followed by 3 h recovery at 15 °C. Thermal preference was quantified using a static temperature preference system (15 °C vs. 10 °C). Metabolic rates returned to resting faster at 10 °C compared with 15 °C, although at 10 °C there was a tradeoff of delayed metabolite recovery. Specifically, post-exercise plasma osmolality, plasma lactate, and muscle lactate remained elevated for the entire period in fish recovering at 10 °C, whereas these parameters returned to resting levels by 6 h in fish from the other two recovery groups. Regardless, fish did not exhibit clear behavioral thermoregulation (i.e., fish overall did not consistently prefer one temperature) to prioritize either physiological recovery process. The advantage of metabolic rate recovery at cooler temperatures may balance against the advantage of metabolite recovery at warmer temperatures, lessening the usefulness of behavioral thermoregulation as a post-exercise recovery strategy in fish.
Competing Interests: Declaration of competing interest The authors have no known competing interests to declare.
(Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)
Databáze: MEDLINE
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