Parasites of Cultured Tiger Puffer(Takifugu rubripes) and their Seasonal Occurrences, with Descriptions of Two New Species of Gyrodactylus.

Abstract

Parasites of cultured tiger puffer, Takifugu rubripes, produced in a hatchery, introduced to a culture site in Nagasaki Prefecture in summer and cultured for one year and a half in net cages, were examined bimonthly.Thirteen species of parasites were recorded : ciliates, Trichodina fugu and T. jadranica on the gills, Cryptocaryon irritans in the fins and body surface; myxosporeans, Kudoa shiomitsui in the heart and Multivalvulida gen. sp. (syn. : Septemcapsula yasunagai Hsieh et Chen, 1984) in the brain; monogeneans, Gyrodactylus rubripedis sp. n.on the fins and body surface and Heterobothrium okamotoi on the gills and branchial cavity wall; trematodes, Tetrochetus sp. and Maculifer pacificus in the rectum; acanthocephalan, Longicollum pagrosomi in the rectum; copepods, Caligus fugu on the buccal cavity wall, Pseudocaligus fugu on the body surface and Neobrachiella hugu (syn : Clavellopsis hugu Yamaguti, 1939) on the buccal cavity wall.Gyrodactylus rubripedis sp. n. is different from the most closely related G. pardalidis sp. n. collected from the fins of panther puffer, Takifugu pardalis and finespotted puffer, T. poecilonotus in smaller size of hamuli and shape of the marginal hook proper;the two new gyrodactylids are similar to ones from freshwater fish of the genus Noemacheilus in having inwardly bent root of hamuli, but clearly separated from them by the shape of the ventral bar.In some selected species of parasites, seasonal occurrences are described and possible sources of infection are discussed.