Parasites and hepatic lesions among pink salmon, Oncorhynchus gorbuscha (Walbaum), during early seawater residence

Overview
TitleParasites and hepatic lesions among pink salmon, Oncorhynchus gorbuscha (Walbaum), during early seawater residence
AuthorsSaksida SM, Marty GD, Jones SR, Manchester HA, Diamond CL, Bidulka J, St-Hilaire S
TypeJournal Article
Journal NameJournal of fish diseases
Volume35
Issue2
Year2012
Page(s)137-51
CitationSaksida SM, Marty GD, Jones SR, Manchester HA, Diamond CL, Bidulka J, St-Hilaire S. Parasites and hepatic lesions among pink salmon, Oncorhynchus gorbuscha (Walbaum), during early seawater residence. Journal of fish diseases. 2012 Feb; 35(2):137-51.

Abstract

Juvenile pink salmon, Oncorhynchus gorbuscha (Walbaum), in the Broughton Archipelago region of western Canada were surveyed over 2 years for sea lice (Lepeophtheirus salmonis and Caligus clemensi), gross and microscopic lesions and evidence of infections with viruses and bacteria. The 1071 fish examined had an approximate ocean residence time no longer than 3 months. A high prevalence of degenerative liver lesions, renal myxosporean parasites and a low prevalence of skin lesions and sea lice were observed. No indications of viral or bacterial diseases were detected in either year. The monthly prevalence of sea lice in 2007 (18-51%) was higher than in 2008 (1-26%), and the infestation density exceeded the lethal threshold in only two fish. Degenerative hepatic lesions and renal myxosporean parasites occurred in approximately 40% of the pink salmon examined in June of both years, and the peak monthly prevalence of hepatocellular hydropic degeneration was greater in 2007 (32%, in May) than in 2008 (12%, in June). Logistic regression analysis found skin lesions and hepatocellular hydropic degeneration significantly associated with sea lice. Most parasites and lesions occurred during both years, but the prevalence was often higher in 2007. Fish weight was 35% less in June 2007 than in June 2008, but condition factor was not different. Further research is required to monitor inter-annual variations and aetiology of the liver lesions and to assess their potential role on pink salmon survival.

Author Details
Additional information about authors:
Details
1S M Saksida
2G D Marty
3S R M Jones
4H A Manchester
5C L Diamond
6J Bidulka
7S St-Hilaire
Properties
Additional details for this publication include:
Property NameValue
Publication ModelPrint
ISSN1365-2761
eISSN1365-2761
Publication Date2012 Feb
Journal AbbreviationJ. Fish Dis.
DOI10.1111/j.1365-2761.2011.01330.x
Elocation10.1111/j.1365-2761.2011.01330.x
Copyright© 2012 Blackwell Publishing Ltd.
LanguageEnglish
Language Abbreng
Publication TypeJournal Article
Journal CountryEngland
Publication TypeResearch Support, Non-U.S. Gov't
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PMID: PMID:22233513