The development of salinity tolerance in juvenile pink salmon (Oncorhynchus gorbuscha) ...

Following yolk-sac absorption and gravel emergence pink salmon (Oncorhynchus gorbuscha) migrate into seawater (SW) at as small as 0.2 g. This life-history strategy is in contrast with most anadromous salmonid species that generally spend 1-2 years growing in fresh water (FW) and physiologically prep...

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Bibliographic Details
Main Author: Gallagher, Zoë Sydney Wilson
Format: Text
Language:English
Published: University of British Columbia 2011
Subjects:
Online Access:https://dx.doi.org/10.14288/1.0072398
https://doi.library.ubc.ca/10.14288/1.0072398
Description
Summary:Following yolk-sac absorption and gravel emergence pink salmon (Oncorhynchus gorbuscha) migrate into seawater (SW) at as small as 0.2 g. This life-history strategy is in contrast with most anadromous salmonid species that generally spend 1-2 years growing in fresh water (FW) and physiologically preparing for life in SW before they migrate to SW as smolts. This study characterized for the first time the ontogeny of SW tolerance in pink salmon around the period of yolk-sac absorption. Post-hatch juvenile pink salmon were either held in FW for 26 weeks or transferred to SW every two weeks for 20 weeks to follow % survival, whole body (WB) Na+ and water content, as well as changes in wet and dry mass, gill Na+K+ATPase (NKA) activity and α1a and α1b mRNA isoform expression. An increase in gill NKA activity and the ratio of the α1b/α1a isoform expression, a plateau in WB water and Na+ levels, and the switch from catabolic to anabolic growth were all observed at the time of yolk-sac absorption in fish retained in ...