title: Larval stages of the bluefin tuna blood fluke Cardicola opisthorchis (Trematoda: Aporocotylidae) found from Terebella sp. (Polychaeta: Terebellidae).
abstract: We found aporocotylid larval stages (sporocysts and cercariae) from five individuals of terebellid polychaete Terebella sp., which were collected from seabed substrate and ropes and floats attached to tuna cages in a tuna farm on the coast of Tsushima Island, Nagasaki, Japan. Nucleotide sequences of the regions of internal transcribed spacer 2 ribosomal DNA and 28S ribosomal DNA from these larval stages were 100% identical to those of Cardicola opisthorchis registered in GenBank. C. opisthorchis is a pathogen causing blood fluke infection of Pacific bluefin tuna Thunnus orientalis, which is considered to have a significant impact on the Japanese Pacific bluefin tuna aquaculture industry. This is the first description of the intermediate host of C. opisthorchis. This indicates that the life cycle of C. opisthorchis is completed within tuna farms in this area.
authors.affiliation: Nagasaki Prefectural Institute of Fisheries, Nagasaki 851-2213, Japan. Electronic address: sugihara013465@pref.nagasaki.lg.jp.
authors.forename: Yukitaka
authors.initials: Y
authors.lastname: Sugihara
authors.affiliation: Nagasaki Prefectural Institute of Fisheries, Nagasaki 851-2213, Japan.
authors.forename: Toshiyuki
authors.initials: T
authors.lastname: Yamada
authors.affiliation: Graduate School of Fisheries Science and Environmental Studies, Nagasaki University, Nagasaki 852-8521, Japan.
authors.forename: Akio
authors.initials: A
authors.lastname: Tamaki
authors.affiliation: Osaka Museum of Natural History, Osaka 546-0034, Japan.
authors.forename: Ryohei
authors.initials: R
authors.lastname: Yamanishi
authors.affiliation: Graduate School of Fisheries Science and Environmental Studies, Nagasaki University, Nagasaki 852-8521, Japan.
authors.forename: Kinya
authors.initials: K
authors.lastname: Kanai
mesh_terms: D000818:Animals; D005393:Fish Diseases / Q000469:parasitology*; D007814:Larva / Q000033:anatomy & histology / Q000145:classification / Q000235:genetics; D008969:Molecular Sequence Data; D011077:Polychaeta / Q000469:parasitology*; D014200:Trematoda / Q000033:anatomy & histology* / Q000145:classification* / Q000235:genetics; D014413:Tuna / Q000469:parasitology*
keywords: Blood fluke; Cardicola opisthorchis; Intermediate host; Pacific bluefin tuna; Terebellidae; Thunnus orientalis