Parasitic infection by larval helminths in Antarctic fishes: pathological changes and impact on the host body condition index

Diseases of Aquatic Organisms

Giuseppe Nascetti¹  Roberta Cimmaruta¹  Simonetta Mattiucci¹  Paolo Cipriani¹  Bruno Bellisario¹  Thierry Work¹  Mario Santoro¹  Valentina Nardi¹ 

关键词: Diphyllobothridean;    Tetraphyllidean;    Contracaecum osculatum s.l.;    Antarctic fish;    Ross Sea;    Pathology;   

DOI  :  10.3354/dao02626

学科分类：生物科学（综合）

来源: Inter-Research

【 摘 要 】

ABSTRACT: We examined pathological changes and relationship between body condition index (BCI) and parasitic infection in 5 species of fish, including 42 icefish Chionodraco hamatus (Channichtyidae), 2 dragonfish Cygnodraco mawsoni (Bathydraconidae), 30 emerald rock cod Trematomus bernacchii, 46 striped rock cod T. hansoni and 9 dusty rock cod T. newnesi (Nototheniidae) from the Ross Sea, Antarctica. All parasites were identified by a combination of morphology and mtDNA cytochrome-oxidase-2 sequence (mtDNA cox2) analysis, except Contracaecum osculatum s.l., for which only the latter was used. Five larval taxa were associated with pathological changes including 2 sibling species (D and E) of the C. osculatum species complex and 3 cestodes including plerocercoids of a diphyllobothridean, and 2 tetraphyllidean forms including cercoids with monolocular and bilocular bothridia. The most heavily infected hosts were C. hamatus and C. mawsoni, with C. hamatus most often infected by C. osculatum sp. D and sp. E and diphyllobothrideans, while C. mawsoni was most often infected with tetraphyllidean forms. Histologically, all fish showed varying severity of chronic inflammation associated with larval forms of helminths. Diphyllobothrideans and C. osculatum spp. were located in gastric muscularis or liver and were associated with necrosis and mild to marked fibrosis. Moderate multifocal rectal mucosal chronic inflammation was associated with attached tetraphyllidean scolices. C. hamatus showed a strong negative correlation between BCI and parasite burden.

【 授权许可】

Unknown