著者

Kazuya Nagasawa Masato Nitta

出版者

Carcinological Society of Japan

雑誌

Crustacean Research (ISSN:02873478)

巻号頁・発行日

vol.47, pp.5-8, 2018 (Released:2018-01-13)

参考文献数

15

被引用文献数

1

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Over more than one century since 1894, cymothoid isopods attached by the diclidophorid monogenean Choricotyle elongata (Goto, 1894) in the mouth cavity of Japanese sparids have not been exactly identified. This note reports that those isopods are identifiable as Ceratothoa verrucosa (Schioedte & Meinert, 1883) based on material of the species attached by Ch. elongata in the mouth cavity of a red seabream, Pagrus major (Temminck & Schlegel, 1843), from the Seto Inland Sea.

著者

Masato Nitta Kazuya Nagasawa

出版者

The Japanese Society of Systematic Zoology

雑誌

Species Diversity (ISSN:13421670)

巻号頁・発行日

vol.28, no.1, pp.69-97, 2023-04-20 (Released:2023-04-20)

参考文献数

152

被引用文献数

2

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In this study we describe one new species of Dactylogyrus Diesing, 1850 and three new species of Bivaginogyrus Gussev and Gerasev in Gussev, 1985 (Monogenea: Dactylogyridae) from two freshwater fishes Gnathopogon elongatus elongatus (Temminck and Schlegel, 1846) and G. caerulescens (Sauvage, 1883) (Cypriniformes: Gobionidae) endemic to Japan. Further, G. elongatus is a new host record for Paradiplozoon skrjabini Achmerov, 1974 (Monogenea: Diplozoidae). Dactylogyrus tamoroko n. sp. is most similar to D. chenjiagengi Zhang in Zhang, Zhou, and Wen, 1990, D. clypeatus Gussev, 1955, and D. gnathopogonis Yamaguti, 1963; it differs from these three congeners by the bifurcate base of the accessory piece. Bivaginogyrus japonicus n. sp. is close to D. polylepidis Alvarez Pellitero, Simon Vicente, and Gonzalez Lanza, 1981, but it can be separated from the latter species based on its uniform-sized marginal hooks. The new species was connected to the cartilage tissue of the gill using filament-like structures, which are assumed to be derived from secretions of the reservoirs associated with each marginal hook. Bivaginogyrus cingulatus n. sp. resembles D. navicularis Gussev, 1955, D. trullaeformis Gussev, 1955, and D. imberbis Wu and Wang, 1983, but the new species is distinguished from these three species by having its inconspicuous outer roots. Bivaginogyrus exiguus n. sp. is comparable to D. pandus Wu and Wang, 1983 and D. colpodes Wu, Wang, and Song, 1983, but differs from these two species in having a shorter penis. Molecular phylogenetic analysis indicates that Bivaginogyrus is a paraphyletic group and shows affinity to “Dactylogyrus” species parasitic on gobionid fishes. However, most of those closely related Dactylogyrus species are yet to be described for their internal morphology and should accordingly be redescribed. The three new species of Bivaginogyrus are assumed to have been co-introduced along with G. e. elongatus into non-native regions of this host.

著者

Kazuya Nagasawa Daisuke Kishi Tetsuya Tokuhara

出版者

The Japanese Society of Systematic Zoology

雑誌

Species Diversity (ISSN:13421670)

巻号頁・発行日

vol.27, no.1, pp.159-166, 2022-04-22 (Released:2022-04-22)

参考文献数

42

被引用文献数

2

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Argulus coregoni Thorell, 1864 was collected from white-spotted char, Salvelinus leucomaenis (Pallas, 1814), red-spotted masu salmon, Oncorhynchus masou ishikawae Jordan and McGregor, 1925, masu salmon, O. m. masou (Brevoort, 1856), and a hybrid between white-spotted char and masu salmon in mountain streams, Gifu Prefecture, central Japan. The host’s body surface under and near the pectoral fins was the most common infection site for A. coregoni. The infected white-spotted char were caught at high elevations (461–873 m) in the headwater streams. The infected individuals of the two masu salmon subspecies were mostly caught in the upper river reaches, but the elevations where they were caught were lower (237–733 m and 660–707 m, respectively) than those of the white-spotted char. Since A. coregoni is also known as a parasite of ayu, Plecoglossus altivelis altivelis (Temminck and Schlegel, 1846), in the middle and lower river reaches in the prefecture, this parasite utilizes different fish species as its hosts along a river course: white-spotted char and the two masu salmon subspecies serve as the hosts, respectively, in the headwater and the middle to lower sections of the upper reaches, but in the mid- and lower river reaches, ayu is the important host.

著者

Kazuya Nagasawa

出版者

Carcinological Society of Japan

雑誌

Crustacean Research (ISSN:02873478)

巻号頁・発行日

vol.49, pp.221-223, 2020-11-06 (Released:2020-11-06)

参考文献数

6

被引用文献数

1

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An ovigerous female of the cymothoid isopod Nerocila trichiura (Miers, 1877) was collected from the isthmus of Cheilopogon doederleinii (Steindachner, 1887) (Beloniformes: Exocoetidae), in Kowaura Bay, Mie Prefecture, central Japan. This represents the third record of N. trichiura from the western Pacific Ocean, and C. doederleinii is a new host of the isopod. A skin wound caused by the isopod was found at attachment site.

著者

Masato Nitta Kazuya Nagasawa

出版者

The Japanese Society of Systematic Zoology

雑誌

Species Diversity (ISSN:13421670)

巻号頁・発行日

vol.22, no.2, pp.117-125, 2017-11-25 (Released:2017-12-05)

参考文献数

55

被引用文献数

4

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Haplocotyle japonica n. gen., n. sp. (Monogenea: Microbothriidae) is described from the skin and gill cavity of Rhinobatos hynnicephalus Richardson, 1846 (Elasmobranchii: Rajiformes: Rhinobatidae) in the Seto Inland Sea off Hiroshima Prefecture and the southern Sea of Japan off Fukuoka Prefecture, Japan. The new genus is closely related to Dermophthirioides Cheung and Nigrelli, 1983, Dermophthirius MacCallum, 1926, Dermopristis Kearn, Whittington, and Evans-Gowing, 2010, and Pseudoleptobothrium Young, 1967 in common morphological features (i.e., the anterior extremity of the oötype having a tetrahedral shape, the anterior aperture of a bell-shaped pharynx, and the structure of the male copulatory organ) but differs from the latter four genera by the presence of a single testis and an ovary not looping the intestinal caeca. The phylogenetic analysis based on 28S rDNA sequences suggests that the new species shows affinity with Dermophthirius and Dermopristis. All currently known species of Microbothriidae Price, 1936 are listed, and a key to 12 genera, including Haplocotyle n. gen., of the family is provided.

著者

Kazuya Nagasawa

出版者

The Japanese Society of Systematic Zoology

雑誌

Species Diversity (ISSN:13421670)

巻号頁・発行日

vol.28, no.2, pp.205-215, 2023-10-26 (Released:2023-10-26)

参考文献数

63

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Argulus nobilis Thiele, 1904 is an ectoparasite of gars (Lepisosteidae) in the U.S.A. Five female specimens of A. nobilis were found in the collection of the Lake Biwa Museum, Japan. This is the first record of the species from Japan and outside the U.S.A. The specimens were collected from an unidentified gar and shortnose gar, Lepisosteus platostomus Rafinesque, 1820. Based on a detailed examination of the specimens, the adult female of A. nobilis is redescribed. The finding from shortnose gar represents a new host record for this parasite. The specimens of A. nobilis were collected in 1992, and it is unknown whether they were taken from gars soon after imported from the U.S.A. or those that had been held in Japan.

著者

Kazuya Nagasawa Masato Hirose

出版者

The Japanese Society of Systematic Zoology

雑誌

Species Diversity (ISSN:13421670)

巻号頁・発行日

vol.26, no.2, pp.289-296, 2021-10-14 (Released:2021-10-14)

参考文献数

26

被引用文献数

2

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An ovigerous female of a fish ectoparasite Argulus caecus C. B. Wilson, 1922 was collected from a squid, probably Todarodes pacificus (Steenstrup, 1880), from a fixed net installed in Otsuchi Bay, an inlet of the northwestern Pacific Ocean, Iwate Prefecture, northen Japan. Since the original description of A. caecus was insufficient, this paper reports on the morphology of the species based on a detailed examination of the female. In particular, the first and second antennae, the first and second maxillae, and four pairs of legs, whose features were poorly known, are reported in detail. The specimen of A. caecus is inferred to have detached itself and moved from a fish host, perhaps a coastal puffer, to the squid while these two animals were trapped in the net or when they were removed from the net. Following Argulus scutiformis Thiele, 1900, A. caecus is the second species of Argulus found from northern Japan located in the northern temperate or subarctic region, and its occurrence in this region is likely to be affected by the Tsushima Warm Current and its branch, the Tsugaru Warm Current, both of which flow off the coast of the region.

著者

Kazuya Nagasawa Takato Asayama Yasufumi Fujimoto

出版者

The Japanese Society of Systematic Zoology

雑誌

Species Diversity (ISSN:13421670)

巻号頁・発行日

vol.27, no.1, pp.167-179, 2022-04-22 (Released:2022-04-22)

参考文献数

60

被引用文献数

3

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Both adult females and males of Argulus mongolianus Tokioka, 1939 were collected from the buccal cavity wall and body surface of freshwater fishes in Lake Izunuma and Lake Uchinuma, Miyagi Prefecture, northen Honshu, Japan. The original description of the species was insufficient, based on a single female from Inner Mongolia, China, and no further description has been made to date. Thus, this paper redescribes A. mongolianus based on the newly-collected specimens, including the first description of the male. This represents the first record of A. mongolianus from Japan. The infected fishes were largemouth bass, Micropterus salmoides (Lacepède, 1802), common carp, Cyprinus carpio Linnaeus, 1758, Japanese white crucian carp, Carassius cuvieri Temminck and Schlegel, 1846, and silver crucian carp, Carassius sp. The three species other than common carp are new host records for A. mongolianus. This parasite was most probably introduced with an unspecified freshwater fish from China into Japan.

著者

Kazuya Nagasawa Masaya Fujimoto

出版者

Carcinological Society of Japan

雑誌

Crustacean Research (ISSN:02873478)

巻号頁・発行日

vol.47, pp.29-33, 2018 (Released:2018-03-31)

参考文献数

14

被引用文献数

2

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Anilocra prionuri Williams & Bunkley-Williams, 1986, is reported based on a female specimen collected from the skin below the nostril of a scalpel sawtail, Prionurus scalprum Valenciennes, 1835, in the southern East China Sea off Kuchinoerabu-jima Island, one of the northern Ryukyu Islands, southern Japan. Anilocra prionuri was previously reported only from off the Pacific coast of central Hon­shu, Japan, but the present collection extends the geographical distribution range of the species from central Honshu southwest to the northern Ryukyu Islands and represents its first record from the East China Sea. The fish had a wound with heavily damaged epidermis at the attachment site of A. prionuri. It was a rare parasite of P. scalprum at the collection site.

著者

Kazuya Nagasawa

出版者

The Japanese Society of Systematic Zoology

雑誌

Species Diversity (ISSN:13421670)

巻号頁・発行日

vol.28, no.2, pp.217-223, 2023-10-26 (Released:2023-10-26)

参考文献数

45

被引用文献数

2

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Argulus japonicus Thiele, 1900 and Argulus coregoni Thorell, 1864 are ectoparasites of freshwater fishes and are known to occur in Lake Biwa and its adjacent inland waters in Shiga Prefecture, central Japan. Since these parasites are not common in the wild in Japan, this study examined the specimens loaned from the Lake Biwa Museum and those previously reported from this prefecture in order to clarify their distributional patterns. The specimens of A. japonicus were obtained in Lake Biwa and a nearby pond, whereas those of A. coregoni were almost exclusively collected in the large rivers flowing into the lake and most of them were from mountain streams which are higher-elevated than the lake or pond. These results indicate both A. japonicus and A. coregoni has its own habitat preference dependent on different environmental conditions: A. japonicus inhabits the still or slow-flowing waters, but A. coregoni occurs in the running waters, especially in the colder, well oxygenated mountain streams.

著者

Kazuya Nagasawa Susumu Isozaki

出版者

Carcinological Society of Japan

雑誌

Crustacean Research (ISSN:02873478)

巻号頁・発行日

vol.46, pp.153-159, 2017 (Released:2017-11-15)

参考文献数

38

被引用文献数

3

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The cymothoid isopod Nerocila phaiopleura Bleeker, 1857 is a skin parasite of actinopterygian fishes in the Indo-West Pacific. The isopod is reported from three species of fishes, viz., Japanese barracuda, Sphyraena japonica Bloch & Schneider, 1801 (Sphyraenidae), Japanese jack mackerel, Trachurus japonicus (Temminck & Schlegel, 1844) (Carangidae), and round herring, Etrumeus micropus (Temminck & Schlegel, 1846) (Dussumieriidae), in coastal waters of the northwest Pacific Ocean off Mie Prefecture, central Japan. These three fish species represent new host records for N. phaiopleura. Based on the literature published between 1857 and 2017, 44 nominal and some unidentified species in four orders and 14 families of fishes have been reported as the hosts of N. phaiopleura, and 18 nominal species of them belong to two clupeiform families (10 spp. in Clupeidae and 8 spp. in Engraulidae). This indicates that N. phaiopleura utilizes a wide variety of fish species as its hosts but prefers the fishes of the two families. The infected fish examined in this study had a large skin wound caused by N. phaiopleura.

著者

Masato Nitta Kazuya Nagasawa

出版者

日本動物分類学会

雑誌

Species Diversity (ISSN:13421670)

巻号頁・発行日

vol.21, no.2, pp.95-104, 2016-11-25 (Released:2017-02-03)

参考文献数

42

被引用文献数

7

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Four alien monogeneans, Unilatus unilatus Mizelle and Kritsky, 1967, U. brittani Mizelle, Kritsky, and Crane, 1968, Trinigyrus peregrinus n. sp., and Heteropriapulus heterotylus (Jogunoori, Kritsky, and Venkatanarasaiah, 2004), were collected from the gills of vermiculated sailfin catfish, Pterygoplichthys disjunctivus (Weber, 1991) (Siluriformes: Loricariidae), in inland waters of Okinawa-jima island, Okinawa Prefecture, Japan. Unilatus unilatus and U. brittani represent new country records for Japan. Trinigyrus peregrinus n. sp. is characterized by a coiled male copulatory organ that forms a circle and does not articulate with its accessory piece. Heteropriapulus heterotylus was newly collected from two rivers in south-central Okinawa-jima island. These monogeneans are all considered to be native to South America and to have been co-introduced with the host fish into the inland waters of the island by release of ornamental pet fish.

著者

Masato Nitta Kazuya Nagasawa

出版者

The Japanese Society of Systematic Zoology

雑誌

Species Diversity (ISSN:13421670)

巻号頁・発行日

vol.25, no.1, pp.61-73, 2020-02-15 (Released:2020-02-15)

参考文献数

147

被引用文献数

5

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Four species of alien parasites, Dactylogyrus skrjabini Achmerow, 1954, D. hypophthalmichthys Achmerow, 1952, D. wuhuensis Lee, 1960 (Platyhelminthes: Monogenea: Dactylogyridae), and Sinergasilus lieni Yin, 1949 (Crustacea: Copepoda: Ergasilidae), were collected from the gills of the alien cyprinid, the silver carp Hypophthalmichthys molitrix (Valenciennes, 1844) in the Watarase River flowing into the Watarase Retarding Basin, Tochigi Prefecture, central Japan. These alien parasites represent new geographical records from Japan. The generic position of D. skrjabini has been doubted because its dorsal anchor shape is similar to those of Pellucidhaptor spp. (Dactylogyridae), but the species should be assigned to Dactylogyrus based on the phylogenetic analysis of 28S rDNA made in this study. The scientific name “Pseudergasilus polycolpus Markewitsch, 1939” is an incorrect subsequent spelling of P. undulatus Markewitsch, 1940, and S. lieni is the oldest available name that can be applied to the ergasilid found in this study.

著者

Kazuya Nagasawa Kenyu Suzuki Fumihito Muto

出版者

Carcinological Society of Japan

雑誌

Crustacean Research (ISSN:02873478)

巻号頁・発行日

vol.49, pp.15-21, 2020-02-13 (Released:2020-02-13)

参考文献数

19

被引用文献数

2

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An ovigerous female of Lernaeenicus ramosus Kirtisinghe, 1956 was collected from an areolate grouper, Epinephelus areolatus (Forsskål, 1775), in coastal waters of Suruga Bay (western North Pacific Ocean), Shizuoka Prefecture, central Japan. This represents a new host and the easternmost distribution records for L. ramosus. Based on the literature published between 1956 and 2019, this paper tabulates the known hosts and distribution records of the species in the Indo-West Pacific region. The recent collections of L. ramosus from Japan further support a previous suggestion that the geographical distribution of the species in Japanese waters is affected by two warm currents, the Kuroshio, and its branch, the Tsushima Current.

著者

Kazuya Nagasawa Shigehiko Urawa

出版者

The Japanese Society of Systematic Zoology

雑誌

Species Diversity (ISSN:13421670)

巻号頁・発行日

vol.22, no.2, pp.167-173, 2017-11-25 (Released:2017-12-05)

参考文献数

48

被引用文献数

2

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The lernaeopodid copepod Tracheliastes sachalinensis Markevich, 1936 was found on the fins of three species of the subfamily Leuciscinae Bonaparte, 1846 (Cypriniformes: Cyprinidae): big-scaled redfin, Tribolodon hakonensis (Günther, 1877); Sakhalin redfin, Tribolodon sachalinensis (Nikolskii, 1899); and lake minnow Rhynchocypris percnurus (Pallas, 1814); collected in three lakes (Lake Tôro, Lake Shirarutoro, and Lake Abashiri) and two rivers (Mena River and Jirô-sawa River), Hokkaido, northern Japan. These findings represent the first records of Tracheliastes sachalinensis from Japan and also from outside of Russia, in which the copepod has hitherto been found. The species is specific to leuciscine fishes in the subarctic region of the Russian Far East and Japan. We also provide a review of parasitic copepods of freshwater fishes from Hokkaido.

著者

Masato Nitta Kazuya Nagasawa

出版者

日本動物分類学会

雑誌

Species Diversity (ISSN:13421670)

巻号頁・発行日

vol.22, no.1, pp.1-5, 2017-05-25 (Released:2017-05-25)

参考文献数

25

被引用文献数

3

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Dactylogyrus oryziasi n. sp. (Monogenea: Dactylogyridae) is described from the gills of the southern medaka Oryzias latipes (Temminck and Schlegel, 1846) (Beloniformes: Adrianichthyidae) collected from an irrigation canal, Tokushima city, Tokushima Prefecture, Shikoku, Japan. This new species resembles Dactylogyrus rysavyi Ergens, 1970 in having a coiled penis passing through a tube of an accessory piece associated with a sigmoid rod, and shapes of haptoral parts, but these species differ from each other by turns of the penis and a connection point between the rod and tube of the accessory piece. This is the first record of Dactylogyrus from beloniform fish.

著者

Kazuya Nagasawa

出版者

The Japanese Society of Systematic Zoology

雑誌

Species Diversity (ISSN:13421670)

巻号頁・発行日

vol.28, no.1, pp.141-146, 2023-05-25 (Released:2023-05-25)

参考文献数

34

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The cystidicolid nematode Salvelinema walkeri (Ekbaum, 1935) is a swim bladder parasite of freshwater salmonids in western North America, ranging from northern California to southern British Columbia. This parasite was found from two age-2.0, juvenile coho salmon Oncorhynchus kisutch (Walbaum, 1792) caught in the southern central Gulf of Alaska in December 1992. This represents the first record of S. walkeri from salmonids caught in offshore waters of the North Pacific Ocean. The two coho salmon harbored as many as 1053 and 278 nematodes, respectively, but there was no significant difference in the condition factor between infected and uninfected fish. The recovered nematodes are highly likely to have been alive in the host swim bladder when the fish were caught because their bodies were in good condition. Based on the observations in this and other papers, S. walkeri is inferred to survive throughout marine residence of salmonids after these fish are infected in streams and enter the sea. While the usefulness of S. walkeri as a stock discrimination tool is less than that of current methods employed for a similar purpose, the potential use of this freshwater parasite as a biological tag is also discussed for studying the ecology of ocean-migrating salmonids.

著者

Kazuya Nagasawa Mizuki Sasaki Hajime Matsubara

出版者

The Japanese Society of Systematic Zoology

雑誌

Species Diversity (ISSN:13421670)

巻号頁・発行日

vol.27, no.2, pp.279-284, 2022-09-22 (Released:2022-09-22)

参考文献数

44

被引用文献数

2

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Specimens of the coastal marine fish leech Limnotrachelobdella okae (Moore, 1924) were collected from the pelvic fins and lateral body surface of big-scaled redfin, Pseudaspius hakonensis (Günther, 1877), in two brackish water lakes, Lake Tofutsu and Lake Abashiri, on the Sea of Okhotsk coast, Hokkaido, northern Japan. The external morphology of the specimens is briefly described, and the two lakes represent new locality records for the leech. Similarly to coastal marine waters, inshore brackish water lakes are suggested to be a habitat in which L. okae can complete its life cycle. Seasonal occurrence of the species may differ between subarctic Hokkaido and three temperate regions of Japan (Honshu, Shikoku, and Kyushu). The role of big-scaled redfin and its congener, Pacific redfin, Pseudaspius brandtii (Dybowski, 1872), in transporting L. okae alive from the coastal sea to brackish and fresh water bodies is discussed in terms of their diadromous migration ecology.

著者

Kazuya Nagasawa

出版者

The Japanese Society of Systematic Zoology

雑誌

Species Diversity (ISSN:13421670)

巻号頁・発行日

vol.26, no.2, pp.137-143, 2021-06-17 (Released:2021-06-17)

参考文献数

35

被引用文献数

4

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Specimens of two species of lernaeopodid copepods, Salmincola edwardsii (Olsson, 1869) and Salmincola markewitschi Shedko and Shedko, 2002, were collected from chars (Salvelinus spp.) reared in exhibition tanks of the Sapporo Salmon Museum, Hokkaido, Japan. Descriptions of these copepods are provided using the specimens. In 1988, adult females of S. edwardsii were found on the gills of southern Asian Dolly Varden, Salvelinus malma krascheninnikova Taranetz, 1933, and those of S. markewitschi in the buccal cavity of whitespotted char, Salvelinus leucomaenis (Pallas, 1814), Nikko char, Salvelinus leucomaenis pluvius (Hilgendorf, 1876), and brook trout, Salvelinus fontinalis (Mitchill, 1814). These copepods are considered to have been introduced to the museum in the late 1980s along with wild chars transported live from natural waters of Hokkaido. Adult copepods have been manually removed using forceps once or twice a year from reared chars, but such infrequent practices have not been effective to eliminate S. markewitschi, which was thus collected again in 2020. In contrast, S. edwardsii was completely eliminated by stopping rearing an infected population of southern Asian Dolly Varden, to which this parasite is host-specific.

著者

Hirotaka Katahira Hokuto Shirakawa Kazuya Nagasawa

出版者

The Japanese Society of Systematic Zoology

雑誌

Species Diversity (ISSN:13421670)

巻号頁・発行日

vol.19, no.2, pp.157-165, 2014-11-25 (Released:2018-03-30)

被引用文献数

1

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Five species of helminth endoparasite (two digeneans, Brachyphallus crenatus (Rudolphi, 1802) and Lecithaster gibbosus (Rudolphi, 1802); two cestodes, plerocercoids of Nybelinia surmenicola (Okada in Dollfus, 1929) and a tetraphyllidean; and an acanthocephalan, post-cystacanths of Bolbosoma sp.) were found in adults of Arctic lampreys Lethenteron camtschaticum (Tilesius, 1811) arriving in the lower part of the middle reaches of a river in Hokkaido, Japan, for spawning after a period of growth in the sea. These parasites are all common species previously reported from various marine fishes in the North Pacific and all have complex life-cycles involving host-to-host transmission via a predator-prey relationship. To have become infected with these food-borne parasites, Arctic lampreys need to have ingested various body parts of infected prey fishes at sea. Consequently, the endoparasites recovered suggest that the Arctic lamprey has a role as a predator in marine ecosystems.