title: Gill histopathology of Maria-da-toca Hypleurochilus fissicornis by metacercariae of Bucephalus margaritae (Digenea: Bucephalidae).
abstract: Gills of Maria-da-toca Hypleurochilus fissicornis collected at Ponta do Sambaqui-Florianópolis island-Brazil, were analyzed to describe the histopathology caused by metacercaria of Bucephalus margaritae. Gills were submitted to the routine histological techniques for embedding in paraffin and permanent mounting in Balsam and stereoscopic analysis. Metacercariae showed a branchial infection site pattern for encystations. The branchial infection site pattern is half-basalward in the primary branchial filament with amplitude of the infection of 1-3 metacercaria. Cysts occurred within branchial abductor muscle and cartilaginous and osseous tissues of the gills. Each metacercariae had a contentional hyaline parasitic capsule and melanin-like pigmentation. The half-apicalward region of the primary branchial filaments showed several dysplasia degrees, cartilage and osseous degeneration (pyknosis), thrombosis and immune exudated cells (mainly lymphocytes). Cytopathologies as thickening of the epithelium lining of the secondary branchial filaments were a response of the branchial infection site pattern of the metacercaria. Interlamellar obliteration and fusion of the lamellae due to the hypertrophy and hyperplasia of the epithelial lining as well as chloride cells occurred. Pyknosis of pillar cells and epithelial lining cells from the secondary branchial filaments were also present. Bucephalosis in H. fissicornis gills is no-hemorrhagic and no-fatal branchitis, but could compromises the gill functions and could permits the secondary opportunistic infections.
authors.affiliation: Laboratório de Biologia de Parasitos de Organismos Aquáticos, Instituto de Ciências Biológicas, Universidade Federal do Rio Grande (FURG), Avenida Itália, Km 08, s/n, Caixa Postal 474, Rio Grande, RS CEP 96201-900 Brazil.
authors.forename: Renato Z
authors.initials: RZ
authors.lastname: Silva
authors.affiliation: Departamento de Aquicultura, Centro de Ciências Agrárias, Núcleo de Diagnóstico e Patologia em Aquicultura, Universidade Federal de Santa Catarina (UFSC), Rodovia Ademar Gonzaga, 1346, Itaborubi, Florianópolis, SC CEP 88040-900 Brazil.
authors.forename: Natalia
authors.initials: N
authors.lastname: da Costa Marchiori
authors.affiliation: Departamento de Aquicultura, Centro de Ciências Agrárias, Núcleo de Diagnóstico e Patologia em Aquicultura, Universidade Federal de Santa Catarina (UFSC), Rodovia Ademar Gonzaga, 1346, Itaborubi, Florianópolis, SC CEP 88040-900 Brazil.
authors.forename: Aimê Rachel M
authors.initials: AR
authors.lastname: Magalhães
authors.affiliation: Laboratório de Biologia de Parasitos de Organismos Aquáticos, Instituto de Ciências Biológicas, Universidade Federal do Rio Grande (FURG), Avenida Itália, Km 08, s/n, Caixa Postal 474, Rio Grande, RS CEP 96201-900 Brazil.
authors.forename: João Carlos B
authors.initials: JC
authors.lastname: Cousin
authors.affiliation: Instituto de Oceanografia, Estação Marinha de Aquicultura, Laboratório de Patologia e Imunologia de Organismos Aquáticos, Universidade Federal do Rio Grande (FURG), Rua do Hotel, 02, Rio Grande, RS CEP 96210-030 Brazil.
authors.forename: Luis Alberto
authors.initials: LA
authors.lastname: Romano
authors.affiliation: Laboratório de Biologia de Parasitos de Organismos Aquáticos, Instituto de Ciências Biológicas, Universidade Federal do Rio Grande (FURG), Avenida Itália, Km 08, s/n, Caixa Postal 474, Rio Grande, RS CEP 96201-900 Brazil.
authors.forename: Joaber
authors.initials: J
authors.lastname: Pereira
keywords: Abnormal gill; Branchitis; Bucephalosis; Pattern of branchial infection