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Developmental hypoxia has negligible effects on long-term hypoxia tolerance and aerobic metabolism of Atlantic salmon (Salmo salar)
journal contributionposted on 2023-05-19, 04:10 authored by Andrew WoodAndrew Wood, Clark, TD, Sarah AndrewarthaSarah Andrewartha, Elliott, NG, Peter FrappellPeter Frappell
Exposure to developmental hypoxia can have long-term impacts on the physiological performance of fish because of irreversible plasticity. Wild and captive-reared Atlantic salmon (Salmo salar) can be exposed to hypoxic conditions during development and continue to experience fluctuating oxygen levels as juveniles and adults.Here,we examine whether developmental hypoxia impacts subsequent hypoxia tolerance and aerobic performance of Atlantic salmon. Individuals at 8°C were exposed to 50% (hypoxia) or 100% (normoxia) dissolved oxygen (DO) saturation (as percent of air saturation) from fertilization for ∼100 d (800 degree days) and then raised in normoxic conditions for a further 15mo. At 18mo after fertilization, aerobic scope was calculated in normoxia (100% DO) and acute (18 h) hypoxia (50% DO) from the difference between the minimum and maximum oxygen consumption rates (ṀO2 min and ṀO2 max, respectively) at 107°C. Hypoxia tolerance was determined as the DO at which loss of equilibrium (LOE) occurred in a constantly decreasing DO environment. There was no difference in ṀO2 min, ṀO2 max, or aerobic scope between fish raised in hypoxia or normoxia. There was some evidence that hypoxia tolerance was lower (higher DO at LOE) in hypoxiaraised fish compared with those raised in normoxia, but the magnitude of the effect was small (12.52% DO vs. 11.73% DO at LOE). Acute hypoxia significantly reduced aerobic scope by reducing ṀO2 max, while ṀO2 min remained unchanged. Interestingly, acute hypoxia uncovered individual-level relationships between DO at LOE and ṀO2 min, ṀO2 max, and aerobic scope. We discuss our findings in the context of developmental trajectories and the role of aerobic performance in hypoxia tolerance.
Publication titlePhysiological and Biochemical Zoology
Department/SchoolInstitute for Marine and Antarctic Studies
PublisherUniv Chicago Press
Place of publication1427 E 60Th St, Chicago, USA, Il, 60637-2954
Rights statementCopyright 2017 The University of Chicago. All rights reserved.