Kazuya Nagasawa

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A new species of parasitic copepod, Choniomyzon inflatus n. sp., is described based on specimens collected from the external egg masses of the smooth fan lobster Ibacus novemdentatus Gibbes captured in the North Pacific Ocean off Ainan, Ehime Prefecture, western Japan. The new species differs from its congeners in having a globular to ovoid prosome, in(More)
Four new species of the genus Hatschekia Poche, 1902 (Copepoda: Siphonostomatoida: Hatschekiidae) are described based on female specimens collected from pufferfishes (Tetraodontiformes: Tetraodontidae) caught in coastal waters off the Ryukyu Islands, Japan: H. longiabdominalis sp. n. on Arothron hispidus (Linnaeus), H. geniculata sp. n. on A. hispidus (type(More)
A new species of copepod, Sarcotretes umitakaesp. n., of the siphonostomatoid family Pennellidae is described based on female specimens from the rattail Coelorinchus jordani Smith and Pope (Actinopterygii: Gadiformes: Macrouridae) caught in the East China Sea. This species is characterized by exhibiting the following characters: the large proboscis projects(More)
The continental origins of chinook salmon (Oncorhynchus tshawytscha) in the North Pacific Ocean and Bering Sea were estimated by using two freshwater parasites (Myxobolus arcticus and M. kisutchl) as biological tags. The parasite survey of adult chinook salmon from major spawning rivers in North America and Kamchatka indicated that M. arcticus was commonly(More)
Five helminths, including a new echinorhynchid acanthocephalan Acanthocephalus longiacanthus n. sp., are described based on specimens from the giant mottled eel Anguilla marmorata Quoy & Gaimard caught in a small river, western Japan. The new acanthocephalan is distinguished from the other congeners in terms of hook arrangement (8–9 longitudinal rows with(More)
Four new species of splanchnotrophid copepods are described based on specimens collected from 5 species of doridacean nudibranchs from coastal waters of Japan. They belong to 3 genera, one of which, Majimun gen. n., is new. The parasites and their hosts are as follows: Ceratosomicola japonicasp. n. ex Hypselodoris festiva (A. Adams); Splanchnotrophus(More)
1. Introduction In the past few years, radiofrequency (RF) devices, which are usually used in the vicinity of the human body, are increasing. Therefore, it might be inferred that pregnant women and their fetuses are exposed to the electromagnetic (EM) waves radiated from the devices, e.g., portable radio terminals, induction heating cooker, hand-held metal(More)
During the 1980s and 1990s, scientific research cruises were conducted in both the eastern and western boundary regions of the North Pacific Ocean. The main purpose of these cruises was to examine the abundance and distribution patterns of juvenile salmon in coastal waters. These studies created one of the most extensive databases ever collected on the(More)
A new species of the monotypic genus Leposphilus Hesse, 1866 (Cyclopoida: Philichthyidae), Leposphilus vogti n. sp., is described based on adult female and male specimens from the interorbital canals of Micropogonias furnieri (Desmarest) (Sciaenidae) in Sepetiba Bay, State of Rio de Janeiro, Brazil. The new species differs from its only congener, L. labrei(More)