Simulated maternal stress reduces offspring aerobic swimming performance in Pacific salmon. Issue 1 (18th December 2019)

• Record Type: Journal Article
• Authors: Banet, Amanda I; Healy, Stephen J; Eliason, Erika J; Roualdes, Edward A; Patterson, David A; Hinch, Scott G
• Editors: Cooke, Steven
• Is Part Of: Conservation physiology. Volume 7:Issue 1(2019)
• Publication Date: 2019-12-18
• Subjects: cortisol -- maternal effects -- Oncorhynchus -- Pacific salmon -- respirometry -- swimming performance; Nature -- Effect of human beings on -- Periodicals; Conservation biology -- Periodicals; 577.05
• DOI: 10.1093/conphys/coz095
• Languages: English
• ISSNs: 2051-1434

Abstract

Abstract: Pacific salmon routinely encounter stressors during their upriver spawning migration, which have the potential to influence offspring through hormonally-mediated maternal effects. To disentangle genetic vs. hormonal effects on offspring swimming performance, we collected gametes from three species of Pacific salmon (Chinook, pink and sockeye) at the end of migration and exposed a subset of eggs from each female to cortisol baths to simulate high levels of maternal stress. Fertilised eggs were reared to fry and put through a series of aerobic swim trials. Results show that exposure to cortisol early in development reduces maximum oxygen consumption while swimming, and decreases aerobic scope in all three species. Resting oxygen consumption did not differ between cortisol and control treatment groups. We also examined several metrics that could influence aerobic performance, and found no differences between treatment groups in haematocrit%, haemoglobin concentration, heart mass, citrate synthase activity or lactate dehydrogenase activity. Though it was not the focus of this study, an interesting discovery was that pink salmon had a higher MO2max and aerobic scope relative to the other species, which was supported by a greater haematocrit, haemoglobin, a larger heart and higher CS activity. Some management and conservation practices for Pacific salmon focus efforts primarily on facilitating adult spawning. However, if deleterious effects of maternal stress acquired prior to spawning persist into the next generation, consideration will need to be given to sub-lethal effects that could be imparted onto offspring from maternal stress. Abstract : Lay summaries We investigated whether maternal stress in Pacific salmon can influence aerobic swimming performance of offspring, through stress hormones deposited into the eggs. We found that offspring exposed to higher levels of the stress hormone cortisol at fertilisation had poorer aerobic swimming performance, which may reduce survival in the wild.