DAO 53:257-262 (2003)  -  doi:10.3354/dao053257

Immunohistochemistry, ultrastructure and pathology of gills of Abramis brama from Lake Mondsee, Austria, infected with Ergasilus sieboldi (Copepoda)

Bahram Sayyaf Dezfuli1,*, Luisa Giari1, Robert Konecny2, Paul Jaeger3, Maurizio Manera4

1Department of Biology, University of Ferrara, Via Borsari 46, 44100 Ferrara, Italy
2Department of Limnology, Institute of Ecology and Conservation Biology, University of Wien, Althanstraße 14, 1090 Wien, Austria
3Land Salzburg, Referat 13/04‹Gewässerschutz Postfach 527, 5010 Salzburg, Austria
4Department of Structure, Functions, Animal Pathology and Biotechnology, University of Teramo, Pizza Aldo Moro 45, 64100 Teramo, Italy

ABSTRACT: Immunohistochemical, ultrastructural and pathological studies were carried out on the gills of bream Abramis brama (L.) from Lake Mondsee, Austria, that were naturally infected with Ergasilus sieboldi Nordmann, 1832. Of a total of 14 specimens of bream examined, the gills of 7 (50%) were parasitized with this copepod and the intensity of infection ranged from 1 to 23 crustaceans per host. Histopathological investigations of infected gill showed extensive tissue damage due to attachment and feeding of the crustacean. Parasites attached close to the base of filaments near the gill arch. Pressure exerted by the ectoparasite attached to the lateral margin of the gill filaments induced atrophy of the secondary lamellae. Tissue reactions included hyperplasia and mucous cell proliferation of the respiratory epithelium. Mucous cells displayed an intense immunohistochemical reactivity with the anti-nitric oxide synthase antibody. In parasitized primary and secondary lamellae, a high number of eosinophilic granular cells and rodlet cells were noticed. Rodlet cells represent an inflammatory cell type closely linked to other piscine inflammatory cells. Presence of a high number of inflammatory cells at the site of E. sieboldi attachment is related to intense host cellular reaction.


KEY WORDS: Ergasilus sieboldi infection · Immunohistochemistry · Ultrastructure · Cellular responses · Gill · Abramis brama


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