Sub‐lethal temperature thresholds indicate acclimation and physiological limits in brook trout Salvelinus fontinalis. Issue 2 (15th June 2020)

• Record Type: Journal Article
• Authors: Morrison, Scott M.; Mackey, Theresa E.; Durhack, Travis; Jeffrey, Jennifer D.; Wiens, Lilian M.; Mochnacz, Neil J.; Hasler, Caleb T.; Enders, Eva C.; Treberg, Jason R.; Jeffries, Ken M.
• Is Part Of: Journal of fish biology. Volume 97:Issue 2(2020)
• Page Start: 583
• Page End: 587
• Publication Date: 2020-06-15
• Subjects: body condition -- critical thermal maxima -- fish -- hepato‐somatic index -- lactate -- osmolality; Fishes -- Periodicals; Fishes -- Great Britain -- Periodicals; 597
• DOI: 10.1111/jfb.14411
• Languages: English
• ISSNs: 0022-1112

Abstract

Abstract: The upper thermal tolerance of brook trout Salvelinus fontinalis was estimated using critical thermal maxima (CTmax ) experiments on fish acclimated to temperatures that span the species' thermal range (5–25°C). The CTmax increased with acclimation temperature but plateaued in fish acclimated to 20, 23 and 25°C. Plasma lactate was highest, and the hepato‐somatic index ( I H ) was lowest at 23 and 25°C, which suggests additional metabolic costs at those acclimation temperatures. The results suggest that there is a sub‐lethal threshold between 20 and 23°C, beyond which the fish experience reduced physiological performance.