Physiological responses to a short-term, environmentally realistic, acute heat stress in Atlantic salmon, Salmo salar

Atlantic salmon populations are declining, and warming river temperatures in the summer months are thought to be a significant contributing factor. We describe the time course of cellular and metabolic responses to an ecologically relevant short-term thermal cycle in juvenile Atlantic salmon. We the...

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Bibliographic Details
Published in:FACETS
Main Authors: Melanie J. Gallant, Sacha LeBlanc, Tyson J. MacCormack, Suzanne Currie
Format: Article in Journal/Newspaper
Language:English
Published: Canadian Science Publishing 2017
Subjects:
L
Q
Online Access:https://doi.org/10.1139/facets-2016-0053
https://doaj.org/article/b0844cd0c2114c41a7ee7335d0994b98
Description
Summary:Atlantic salmon populations are declining, and warming river temperatures in the summer months are thought to be a significant contributing factor. We describe the time course of cellular and metabolic responses to an ecologically relevant short-term thermal cycle in juvenile Atlantic salmon. We then examined whether this heat event would affect tolerance to a subsequent heat shock in terms of critical thermal maximum (CTmax). Fish induced heat shock protein 70 in red blood cells, heart, liver, and red and white muscle; whole blood glucose and lactate transiently increased during the heat cycle. In contrast, we observed no significant effect of a prior heat shock on CTmax. The CTmax was positively correlated with Fulton’s condition factor suggesting that fish with greater energy reserves are more thermally tolerant. Atlantic salmon activate cellular protection pathways in response to a single thermal cycle and appear to cope with this short-term, ∼1 d heat shock, but this challenge may compromise the ability to cope with subsequent heat events.