Uncoupling Thermotolerance and Growth Performance in Chinook Salmon: Blood Biochemistry and Immune Capacity

Abstract

Ocean warming and extreme sea surface temperature anomalies are threatening wild and domesticated fish stocks in various regions. Understanding mechanisms for thermotolerance and processes associated with divergent growth performance is key to the future success of aquaculture and fisheries management. Herein, we exposed Chinook salmon (Oncorhynchus tshawytscha) to environmentally relevant water temperatures (19–20 °C) approaching their upper physiological limit for three months and sought to identify blood biomarkers associated with thermal stress and resilience. In parallel, blood biochemical associations with growth performance were also investigated. Temperature stress-activated leukocyte apoptosis induced a minor immune response, and influenced blood ion profiles indicative of osmoregulatory perturbation, regardless of how well fish grew. Conversely, fish displaying poor growth performance irrespective of temperature exhibited numerous biomarker shifts including haematology indices, cellular-based enzyme activities, and blood clinical chemistries associated with malnutrition and disturbances in energy metabolism, endocrine functioning, immunocompetence, redox status, and osmoregulation. Findings provide insight into mechanisms of stress tolerance and compromised growth potential. Biochemical phenotypes associated with growth performance and health can potentially be used to improve selective breeding strategies.

Acclimation to higher temperature and antioxidant supplemented diets improved rainbow trout (Oncorhynchus mykiss) resilience to heatwaves

“…Within an individual lifetime, its performance such as growth rate, can be altered through acclimation to environmental temperature, exhibiting a phenotypic plasticity pattern. These results align with a study on chinook salmon ( Oncorhynchus tshawytscha ) growth performance metrics during a three-month thermal challenge at 19–20 °C 32 . Schram et al 33 .…”

Impacts of seeding density on the oxidative stress response of the Greenshell™ mussel, Perna canaliculus

“…While both TAC and LP indicate levels of oxidative stress, LP captures the effects of reactive oxygen species (ROS) on polyunsaturated fatty acids critical for growth in juvenile bivalves, but is also related to how metabolically active an organism is, which may not necessarily mean the organism is under stress (Gallager et al 1986;Lulijwa et al 2021;Lushchak 2011). Differences in the conditions experienced by mussel spat among sites and depths influenced TAC, but LP in this study indicated that although factors such as temperature, oxygen, and nutrient availability (Dowd et al 2013;Nogueira et al 2017;Viarengo et al 1995;Wilhelm Filho et al 2001) may have varied among sites and depths causing oxidative damage, the effects of ROS on lipid production was unaffected by these experimental treatments.…”

Acclimation to higher temperature and feeding on antioxidants supplemented diets improved Rainbow trout (Oncorhynchus mykiss) resilience to heatwaves

“…A higher level of selenium micronutrient also plays a vital role in the stability of proteins (Schrauzer, 2003;Sahin et al, 2014). The reduction in total protein levels at the end of thermal shock may also indicate an increase in anaerobic metabolism and protein catabolism, which may predispose sh to death (Islam et al, 2020b;Lulijwa et al, 2021).…”