Browsing by Subject "Cardicola"

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    Blood fluke infection of cage reared Atlantic bluefin tuna Thunnus thynnus in west Mediterranean
    (The Japanase Society of Fish Pathology, 2011) Ruiz de Ybáñez Carnero, María del Rocío; Peñalver, José; Martínez Carrasco-Pleite, Carlos; del Río, Laura; María Dolores, Emilio; Berriatua, Eduardo; Muñoz, Pilar; Sanidad Animal
    Infection of a blood fluke, possibly Cardicola sp. (Digenea: Aporocotylidae), in reared Atlantic bluefin tuna Thunnus thynnus was investigated. Parasitological analyses included visual examination of the heart for the presence of adult fluke and stereomicroscopic and histopathological analyses of the gill to assess the presence of lesions caused by parasite eggs. No adult flukes were found in the hearts. Some of the gills exhibited small white to yellow foci involving single filaments. Blood fluke eggs were found in gill tissue sections of 29.6% of sampled tuna. A slight inflammatory response was observed around most of these eggs, while occasionally individual eggs were encapsulated by a granulomatous reaction. Despite the absence of remarkable pathological effects in the infected tuna, blood flukes combined with other agents may cause major problem.
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    Molecular and morphological identification of Cardicola (Trematoda: Aporocotylidae) eggs in hatchery-reared and migratory Atlantic bluefin tuna (Thunnus thynnus L.)
    (Elsevier, 2015-07-03) Forte-Gil, Débora; Holzer, Astrid S.; Pecková, Hana; Bartošová-Sojková, Pavla; Peñalver, José; Dolores, Emilio Ma.; Muñoz, Pilar; Sanidad Animal
    A microscopic and a molecular approach was used to investigate blood fluke infection in the very first specimens of Atlantic bluefin tuna (Thunnus thynnus, Scombridae) that were born in captivity and that were never moved from their specific cage culture sites in the Mediterranean. Data were compared with infection in wild, migratory bluefin tuna which were captured and fattened along the Spanish Mediterranean coast. Wild and cultured pop ulations sampled in the present study harbored the same Cardicola spp. richness and showed statistically insig nificant differences in overall parasite prevalence. Three morphotypes, crescent-shaped, fusiform and oval eggs, were observed in both non-migrant and migrant tuna. According to partial ITS2 and 28S rDNA sequences they belong to Cardicola opisthorchis, Cardicola forsteri, and to Cardicola sp., a recently described species, phyloge netically closely related to Cardicola orientalis. All three species were simultaneously present in some specimens. No significant difference in overall parasite prevalence was observed, though the prevalence of eggs of individual species, i.e. C. opisthorchis and C. forsteri, was significantly higher in fattened bluefin tuna. Our results strongly support a Mediterranean origin of the three Cardicola species encountered in cultured specimens and suggest that the intermediate hosts of these Cardicola species occur along the Mediterranean coast. Thus, infection with these parasites is not exclusively a result of infections happening along the migratory routes of wild bluefin tuna, in the Atlantic Ocean, as previously suggested. Once transferred to the sea for fattening, Atlantic bluefin tuna are at risk of infection with up to three different species of the genus Cardicola in along the Mediterranean coast in southeast Spain. On the contrary, C. orientalis infections might be associated to long-distance migration and an overlapping Thunnus maccoyii and Thunnus orientalis distribution. Statement of relevance This is the very first parasitological study conducted in T. thynnus born in captivity and cultured local in the Mediterranean. The results show that once transferred to the sea for fattening, they are at risk of infection with up to three different species of the genus Cardicola. These results strongly imply a Mediterranean distribution of these species.