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Research article - Peer-reviewed, 2022

The effects of Contracaecum osculatum larvae on the growth of Atlantic cod (Gadus morhua)

Ovegård, Maria; Ljungberg, Peter; Orio, Alessandro; Öhman, Kristin; Benavente Norrman, Emilia; Lunneryd, Sven-Gunnar;

Abstract

Atlantic cod (Gadus morhua) from the Eastern Baltic stock have decreased in numbers and condition since the 1990′s. Among several causes, an increased prevalence and intensity of the nematode Contracaecum osculatum has been discussed. This increase has been attributed to a population increase of the parasites final host, the grey seal (Halichoerus grypus). Other studies have looked at the role of Contracaecum osculatum on cod growth and condition on recently caught cod, or done short term experimental studies in lab. This study instead investigated the importance of Contracaecum osculatum for cod growth in a sea pen based experiment, where cod were kept and fed in order to monitor growth. The results show that a higher density (number of nematodes per gram liver) decreases cod growth potential. If the number of nematodes exceeded 8 per gram liver cod did not grow in length, even when given generous amounts of food. Accounting for the lack of growth due to Contracaecum osculatum may improve stock assessments and increase the possibility to reach management targets.

Keywords

Anisakidae; Baltic cod; Contracaecum osculatum; Gadus morhua; Parasite

Published in

International Journal for Parasitology: Parasites and Wildlife

2022, volume: 19, pages: 161-168

Authors' information

Swedish University of Agricultural Sciences, Department of Aquatic Resources
Swedish University of Agricultural Sciences, Department of Aquatic Resources
Swedish University of Agricultural Sciences, Department of Aquatic Resources
Swedish University of Agricultural Sciences, Department of Aquatic Resources
Swedish University of Agricultural Sciences, Department of Aquatic Resources
Swedish University of Agricultural Sciences, Department of Aquatic Resources

Sustainable Development Goals

SDG14 Life below water

UKÄ Subject classification

Fish and Aquacultural Science

Publication Identifiers

DOI: https://doi.org/10.1016/j.ijppaw.2022.08.006

URI (permanent link to this page)

https://res.slu.se/id/publ/118902