Resistance to Saprolegnia parasitica infection: A heritable trait in Atlantic salmon

Abstract A controlled Saprolegnia parasitica infection model was used to challenge 1158 fish representing 105 pedigreed Atlantic salmon families to evaluate the possibility of selecting for Saprolegnia resistance in a commercial breeding programme. Fish were infected in five study tanks and observed...

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Bibliographic Details
Published in:Journal of Fish Diseases
Main Authors: Misk, Ehab, Gonen, Serap, Garber, Amber F.
Other Authors: Atlantic Canada Opportunities Agency, New Brunswick Innovation Foundation
Format: Article in Journal/Newspaper
Language:English
Published: Wiley 2022
Subjects:
Online Access:http://dx.doi.org/10.1111/jfd.13664
https://onlinelibrary.wiley.com/doi/pdf/10.1111/jfd.13664
https://onlinelibrary.wiley.com/doi/full-xml/10.1111/jfd.13664
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Summary:Abstract A controlled Saprolegnia parasitica infection model was used to challenge 1158 fish representing 105 pedigreed Atlantic salmon families to evaluate the possibility of selecting for Saprolegnia resistance in a commercial breeding programme. Fish were infected in five study tanks and observed for 40 days post‐infection for lesion score and survival. Survival analysis of the top 10 resistant and bottom 10 susceptible families indicated that the hazard of dying following Saprolegnia infection was 1509% higher in susceptible families. In all fish, a 10 g increase in weight correlated with a 7.8% increase in the hazard of dying while sex did not affect mortality. Resistance to Saprolegnia was estimated to have a heritability of 0.25, indicating that selection is possible. Genetic and phenotypic correlations indicated that the 11‐point scoring system, developed in this study to quantify Saprolegnia infection severity, had a high negative correlation with survival as days to mortality at ≥−0.922(±0.005), suggesting that the scoring method could help assess lesion development in studies where mortality is not the primary biological endpoint.