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

Bibliographic Details
Title: Physiological effects of dissolved oxygen are stage-specific in incubating Atlantic salmon (Salmo salar).
Authors: Wood, Andrew T., Clark, Timothy D., Elliott, Nicholas G., Frappell, Peter B., Andrewartha, Sarah J.
Source: Journal of Comparative Physiology B: Biochemical, Systemic & Environmental Physiology; Feb2019, Vol. 189 Issue 1, p109-120, 12p
Subject Terms: PHYSIOLOGICAL effects of oxygen, EMBRYOS, ATLANTIC salmon, AEROBIC metabolism
Abstract: 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 (M˙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, M˙O2rout or O2crit at any developmental window. In contrast, embryos exposed to hypoxia grew slower and had a lower M˙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. [ABSTRACT FROM AUTHOR]
Copyright of Journal of Comparative Physiology B: Biochemical, Systemic & Environmental Physiology is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
Database: Complementary Index
More Details
ISSN:01741578
DOI:10.1007/s00360-018-1199-5
Published in:Journal of Comparative Physiology B: Biochemical, Systemic & Environmental Physiology
Language:English