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Physiological effects of dissolved oxygen are stage-specific in incubating Atlantic salmon (Salmo salar)

journal contribution
posted on 2023-05-20, 01:48 authored by Wood, AT, Clark, TD, Nicholas Elliott, Peter FrappellPeter Frappell, Sarah AndrewarthaSarah Andrewartha
Oxygen availability is highly variable during salmonid incubation in natural redds and also in aquaculture incubation systems. Hypoxia generally decreases growth and aerobic metabolism prior to hatching, in parallel with eliciting physiological modifications that enhance oxygen delivery. However, it is less-well known whether developmental hyperoxia can drive the opposite effect. Moreover, there is insufficient understanding of stage-specific developmental windows during which ambient oxygen availability may be of greater or lesser impact to incubating embryos. Here, we tested the effects of hypoxia (50% dissolved oxygen: DO, % air saturation) and hyperoxia (150% DO) on the growth, routine aerobic metabolism (O2rout) and hypoxia tolerance (O2crit) of Atlantic salmon (Salmo salar) during seven developmental windows throughout incubation. Embryos exposed to hyperoxia (150% DO) did not differ from the normoxic group in growth, O2rout or O2crit at any developmental window. In contrast, embryos exposed to hypoxia grew slower and had a lower O2rout, but had higher hypoxia tolerance (lower O2crit) than normoxic and hyperoxic counterparts. Interestingly, these differences were only apparent when the embryos were measured prior to hatching. Larvae (alevins) incubated in hypoxia following hatching grew similarly to normoxia-incubated alevins. Our results provide evidence that Atlantic salmon embryos are most sensitive to hypoxia prior to hatching, probably due to increasing (absolute) oxygen requirements concurrent with restricted oxygen diffusion through the egg. Moreover, the similarities between normoxia- and hyperoxia-incubated salmon demonstrate that embryos are not oxygen-limited under normoxic conditions.

History

Publication title

Journal of Comparative Physiology B: Biochemical, Systemic, and Environmental Physiology

Volume

189

Pagination

109-120

ISSN

0174-1578

Department/School

Institute for Marine and Antarctic Studies

Publisher

Springer-Verlag

Place of publication

175 Fifth Ave, New York, USA, Ny, 10010

Rights statement

© Springer-Verlag GmbH Germany, part of Springer Nature 2019

Repository Status

  • Restricted

Socio-economic Objectives

Aquaculture fin fish (excl. tuna); Expanding knowledge in the biological sciences

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