Acute thermal sensitivity varies among full sibling families of Atlantic salmon

Authors: Griffith, Andrew; Legacki, Erin; Boyd, Danielle; Peterson, Brian

Submitted to: Aquaculture Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/1/2025
Publication Date: N/A
Citation: N/A

Interpretive Summary: Aquaculture efforts have the potential to contribute substantially to the future food supply. Selective breeding, efforts to maximize production through the inheritance of complex traits, has transformed terrestrial agricultural practice and has the potential to contribute to future aquaculture production. A major limitation for aquaculture practices, however, are the dynamic environmental conditions in which many are cultivated. Temperature in particular can profound impacts on organism growth and development and can vary greatly among coastal environments. Here were observe the thermal sensitivities of pedigreed families of Atlantic salmon exposed to acute thermal stress in efforts to identify potential contrasting responses. Larval salmon were incubated in respiration chambers along a ten-degree thermal gradient and their responses quantified. Substantial family differences were observed whereby some larval families exhibited the ability to increase their respiration rates with temperature increase as opposed to certain families that were not. Our findings highlight the potential to survey already-existing populations of aquaculture species for contrasting traits that can be used for selection in future breeding efforts to maximize production in stressful environments.

Technical Abstract: Atlantic salmon constitute a growing fishery in the US and is largely reliant upon cage-culture in which fish are cultivated within enclosed nets or pens in environmental settings that are prone to natural variation. Temperature fluctuation in particular can substantially halter or accelerate production. Here we investigate the acute respiratory capacity (respiratory Q10) among pedigreed larval families of Atlantic salmon (Salmo salar) spawned in a hatchery facility exposed to acute thermal stress. Individual larvae from full-sibling families were incubated along a thermal gradient (6 - 16°C) in calibrated respiration chambers and linear declines in oxygen content were used to determine individual respiration rates and family-based Q10. Metabolites from the tri-carboxylic acid pathway, a key pathway involved in cellular energy supply, were quantified in preserved whole tissue from each larval family using liquid chromatography tandem mass spectrometry (LC-MS/MS) to identify potential biochemical markers associated with thermal sensitivity. Clear family × environment interactions were observed whereby some larval families exhibited negative rate-increases with warmer environments as opposed to others that exhibited enhanced respiration rates. Total metabolite content nor the abundance of single metabolite(s) were associated with family-specific trends in respiration rate with temperature. Our findings show that respiration rate Q10 was a useful and sensitive biomarker in identifying contrasting respiration phenotypes among different families of Atlantic salmon while TCA cycle metabolites did not explain differences associated with family specific trends in respiration rates.