Salinity effects on plasma ion levels, cortisol, and osmolality in Chinook salmon following lethal sampling

Comparative Biochemistry and Physiology, Part A: Molecular & Integrative Physiology
By: , and 

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Abstract

Studies on hydromineral balance in fishes frequently employ measurements of electrolytes following euthanasia. We tested the effects of fresh- or salt-water euthanasia baths of tricaine mesylate (MS-222) on plasma magnesium (Mg2+) and sodium (Na+) ions, cortisoland osmolality in fish exposed to saltwater challenges, and the ion and steroid hormone fluctuations over time following euthanasia in juvenile spring Chinook salmon (Oncorhynchus tshawytscha). Salinity of the euthanasia bath affected plasma Mg2+ and Na+concentrations as well as osmolality, with higher concentrations in fish euthanized in saltwater. Time spent in the bath positively affected plasma Mg2+ and osmolality, negatively affected cortisol, and had no effect on Na+ concentrations. The difference of temporal trends in plasma Mg2+ and Na+ suggests that Mg2+ may be more sensitive to physiological changes and responds more rapidly than Na+. When electrolytes and cortisol are measured as endpoints after euthanasia, care needs to be taken relative to time after death and the salinity of the euthanasia bath.

Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Salinity effects on plasma ion levels, cortisol, and osmolality in Chinook salmon following lethal sampling
Series title Comparative Biochemistry and Physiology, Part A: Molecular & Integrative Physiology
DOI 10.1016/j.cbpa.2015.11.011
Volume 192
Year Published 2016
Language English
Publisher Elsevier
Contributing office(s) Coop Res Unit Seattle
Description 6 p.
First page 38
Last page 43