Influences of stress phenotype, nutrition and genetic background on the upper thermal tolerance of Atlantic salmon (Salmo salar) ...

• Main Author: Ignatz, Eric Hans
• Format: Text
• Language: English
• Published: Memorial University of Newfoundland 2024
• Subjects: Atlantic salmon; Salmo salar
• Online Access: https://dx.doi.org/10.48336/s2n4-cn65; https://research.library.mun.ca/16293/

Anthropogenic climate change threatens the sustainability of the Atlantic salmon (Salmo salar) aquaculture industry. This thesis studied the effects of three factors [i) stress phenotype; ii) supplemental dietary cholesterol; and iii) family/genetic background] on the performance of farmed Atlantic salmon when exposed to an incremental thermal maximum (ITMax, +0.2°C day⁻¹) challenge that mimicked natural summer sea-cage conditions. No differences in the ITMax of male Atlantic salmon characterized as either low (LR) or high stress responders (HR) based on measurements of post-stress cortisol levels at 9°C was found, and interestingly, stress phenotypes were no longer distinguishable from one another when post-stress cortisol levels were analyzed at elevated temperatures. However, some differences in gene expression were found between LR and HR fish in response to bacterial immune stimulation. Notably, HR salmon mounted a greater (p < 0.05) innate antibacterial immune response than LR salmon at 20°C, ...