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Ichthyophonus ‐induced cardiac damage: a mechanism for reduced swimming stamina in salmonids
Author(s) -
Kocan R,
LaPatra S,
Gregg J,
Winton J,
Hershberger P
Publication year - 2006
Publication title -
journal of fish diseases
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.819
H-Index - 85
eISSN - 1365-2761
pISSN - 0140-7775
DOI - 10.1111/j.1365-2761.2006.00745.x
Subject(s) - biology , parasite hosting , cardiac muscle , immune system , infiltration (hvac) , anatomy , immunology , world wide web , computer science , physics , thermodynamics
Swimming stamina, measured as time‐to‐fatigue, was reduced by approximately two‐thirds in rainbow trout experimentally infected with Ichthyophonus . Intensity of Ichthyophonus infection was most severe in cardiac muscle but multiple organs were infected to a lesser extent. The mean heart weight of infected fish was 40% greater than that of uninfected fish, the result of parasite biomass, infiltration of immune cells and fibrotic (granuloma) tissue surrounding the parasite. Diminished swimming stamina is hypothesized to be due to cardiac failure resulting from the combination of parasite‐damaged heart muscle and low myocardial oxygen supply during sustained aerobic exercise. Loss of stamina in Ichthyophonus ‐infected salmonids could explain the poor performance previously reported for wild Chinook and sockeye salmon stocks during their spawning migration.