Spatial patterns in infection of cod Gadus morhua with the seal-associated liver worm Contracaecum osculatum from the Skagerrak to the central Baltic Sea

Marine ecology progress series

Per W. Kania^2¹  Kurt Buchmann^2²  Maria Sokolova^1³  Uwe Krumme^3⁴  Bastian Huwer^1⁵ 

[1] Department of Bioscience, Aarhus University, Roskilde 4000, Denmark^4;Department of Veterinary and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Frederiksberg C 1870, Denmark^2;National Institute of Aquatic Resources, Technical University of Denmark (DTU Aqua), Kgs. Lyngby 2800, Denmark^1;National Institute of Aquatic Resources, Technical University of Denmark (DTU Aqua), Silkeborg 8600, Denmark^5;Thünen Institute of Baltic Sea Fisheries, 18069 Rostock, Germany^3

关键词: Parasitic nematode;    Species interactions;    Salinity;    Transport host;    Condition factor;    Feeding ecology;    Grey seal;    Harbour seal;   

DOI  :  10.3354/meps12773

学科分类：海洋学与技术

来源: Inter-Research

【 摘 要 】

Fish serve as transport hosts to a range of parasites, with potential negative effects on fish health. In the Baltic Sea, the grey seal Halichoerus grypus (Fabricius) population has increased markedly since the early 2000s. H. grypus is the main final host to the liver worm Contracaecum osculatum (Rudolphi, 1802), a parasitic nematode to which cod Gadus morhua (Linnaeus) is one of several transport hosts. Recent investigations have shown a marked increase in prevalence and abundance of infection of this parasite in livers of G. morhua inhabiting the central Baltic Sea. Yet no recent knowledge exists on levels of C. osculatum infection in G. morhua in adjacent areas. We investigated spatial differences in prevalence and abundance of this parasitic nematode in livers of G. morhua, covering a transect consisting of 9 areas from the Skagerrak to the eastern part of the central Baltic Sea. We further provide survey data of local abundances of H. grypus and harbour seal Phoca vitulina (Linnaeus) throughout this transect. Prevalence and abundance of C. osculatum sensu stricto in G. morhua livers differed significantly between east and west, with highest levels of infection occurring in the low-salinity central Baltic areas. Fish in the east had significantly lower condition than their westerly conspecifics. Spatial differences in local seal abundance and seal species, salinity and feeding ecology may explain the observed differences in C. osculatum infection between eastern and western G. morhua.

【 授权许可】

Unknown