Specimens of the cystidicolid nematode Salvelinema salmonicola (Ishii, 1916) were collected from the swimbladder of amago salmon Oncorhynchus masou ishikawae and brown trout Salmo trutta in Lake Takase, Yamaguchi Prefecture, western Honshu, Japan. This is the first record of S. salmonicola from Yamaguchi Prefecture and brown trout in Japan, and also the third record of the species from lake-resident salmonids in Japan

Hatama, Toshihiro

Katahira, Hirotaka

Nagasawa, Kazuya

Hiroshima University Institutional Repository

広島大学学術情報リポジトリHiroshima University Institutional RepositoryTitle Salvelinema salmonicola (Nematoda: Cystidicolidae) fromlake-resident salmonids in western Honshu, JapanAuther(s) Nagasawa, Kazuya; Hatama, Toshihiro; Katahira, HirotakaCitation Biogeography , 15 : 103 - 105Issue Date 2013-08-20DOISelf DOIURL http://ir.lib.hiroshima-u.ac.jp/00035285Right (c) The Biogeographical Society of Japan. All rights arereserved.RelationSalvelinema salmonicola (Nematoda: Cystidicolidae) fromlake-resident salmonids in western Honshu, JapanKazuya Nagasawa1*, Toshihiro Hatama2 and Hirotaka Katahira1,31  Graduate School of Biosphere Science, Hiroshima University, 1-4-4 Kagamiyama, Higashi-Hiroshima, Hiroshima, 739-8528 Japan2 Inland Sea Research Division, Yamaguchi Prefectural Fisheries Research Center, 437-77 Aio-Futashima, Yamaguchi, 754-0893 Japan3 Present address: Graduate School of Environmental Science, Hokkaido University,N10 W5, Sapporo, Hokkaido, 060-0810 JapanThe cystidicolid nematode Salvelinema salmoni-cola (Ishii, 1916) Margolis, 1966 is a parasite found in the swimbladder lumen of freshwater salmonids in the North Pacific rim countries (Margolis, 1967, 1968; Moravec & Nagasawa, 1999). In Japan, the species has been reported from Honshu, Hokkaido, and the southern Kurile Islands (Nagasawa et al., 1987; Nagasawa & Furusawa, 2006). During a study of the parasite fauna of freshwater fishes of western Japan, we found the nematode (Fig. 1) in two species of salmonids, amago salmon Oncorhynchus masou ishikawae Jordan & McGregor and brown trout Salmo trutta Linnaeus, caught in Lake Takase (34°10’13.9’’N, 131°46’31.4’’E), Shunan City, Yamaguchi Prefecture, western Honshu, Japan. The lake, ca. 80 ha in surface area, was formed after the construction of a dam in the Shimaji River, one of the tributaries of the Saba River, which empties into the Seto Inland Sea.A total of 20 fishes (15 O. masou ishikawae, four S. trutta, and one rainbow trout Oncorhynchus Abstract.   Specimens of the cystidicolid nematode Salvelinema salmonicola (Ishii, 1916) were collected from the swimbladder of amago salmon Oncorhynchus masou ishikawae and brown trout Salmo trutta in Lake Takase, Yamaguchi Prefecture, western Honshu, Japan. This is the first record of S. salmonicola from Yamaguchi Prefecture and brown trout in Japan, and also the third record of the species from lake-resident salmonids in Japan.Key words: Salvelinema salmonicola, Nematoda, fish parasite, Oncorhynchus masou ishikawae, Salmo trutta, Yamaguchi PrefectureBiogeography 15.103–105．Aug. 20, 2013　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　      *Corresponding author: ornatus@hiroshima-u.ac.jp Fig. 1. Salvelinema salmonicola infecting the swimbladder lumen of an amago salmon Oncorhynchus masou ishikawae, 246 mm SL, caught in Lake Takase, Shunan City, Yamaguchi Prefecture, Japan, on 22 March 2009. Scale bar: 20 mm.A false moray Robinsia sp. from the East China Sea－ 103－mykiss (Walbaum)) were captured by rod and line in Lake Takase from April 2005 to August 2012. Fishes were fixed in 10% formalin or frozen and trans-ported to the laboratory at Hiroshima University, where they were measured for standard length (SL, mm) and examined for parasites. Nematodes from the swimbladder were preserved in 70% ethanol and identified based on Moravec & Nagasawa (1999). Voucher specimens are deposited in the Aschel-minthes (As) collection at the National Museum of Nature and Science (NSMT-As 3960 from O. masou ishikawae; NSMT-As 3961 from S. trutta) in Tsu-kuba, Ibaraki Prefecture, Japan. The scientific names of fishes used in this paper follow those in Nakabo (2013).Four (26.7%) of the 14 O. masou ishikawae (155–495 mm SL) were infected by a total of 39 S. salmonicola (1–17 [mean 9.8] per infected host). One S. salmonicola parasitized one (25.0%) of the four S. trutta (420–530 mm SL). No nematode infection was found in the one O. mykiss (485 mm SL). This is the first record of S. salmonicola from Yamaguchi Prefecture. In Honshu, the main island of Japan, the species has been from Aomori, Ishikawa, Shiga, and Hiroshima prefectures (Nagasawa & Fu-rusawa, 2006). The present finding of the nematode extends its distribution range westward to Yamaguchi Prefecture, the westernmost prefecture in Honshu. Salmo trutta is not native to Japan: it was intro-duced from the U.S.A. into Japan in the late 1920’s (Okumoto, 1989). This fish was released into Lake Takase in 2004 and 2005. The individual of S. trutta infected by the nematode is likely to be one of those released fish. To date, only one species of parasite (the rhabdochonid nematode Rhabdochona onco-rhynchi) has been reported from S. trutta in Japan (Nagasawa et al., 1987). Salvelinema salmonicola is newly added to the parasite fauna of S. trutta of Japan.Our knowledge is limited on the occurrence of S. salmonicola in lake-resident salmonids in Japan, where only two papers (Yamaguti, 1935; Nagasawa et al., 2010) reported its infection in salmonids from two lakes (Lake Biwa and Lake Toya). The finding of S. salmonicola in this study represents the third record of the species from lake-resident salmonids in Japan. Since O. masou ishikawae and S. trutta have not been studied for the ecology in Lake Takase and the Shimaji River, no information is available on their feeding on amphipods, which are known to serve as intermediate hosts for S. salmonicola (Moravec & Nagasawa, 1986). Moreover, O. ma-sou ishikawae is distributed in the main stream and tributaries of the Shimaji River as well as in the lake (Hatama, unpublished data) and some may move be-tween these locations. Therefore, in order to clarify the life cycle and ecology of S. salmonicola, we need to discover its intermediate hosts and study the feeding habits and movement of the salmonids in various locations of the Shimaji River.ReferencesMargolis, L., 1967. The swimbladder nematodes (Cystidicolidae) of Pacific salmons (genus Onco-rhynchus). Can. J. Zool., 45: 1183–1199.Margolis, L., 1968. Review of the Japanese species of Cystidicola, Metabronema and Rhabdochona (Nematoda) from salmonid fishes. Bull. Meguro Parasitol. Mus., (2): 23–44.Moravec, F. & Nagasawa, K., 1986. New records of amphipods as intermediate hosts for salmonid nematode parasites in Japan. Folia Parasitol., 33: 45–49.Moravec, F. & Nagasawa, K., 1999. Morphology and taxonomy of Salvelinema species (Nematoda: Cystidicolidae), swimbladder parasites of Pacific area salmonids. Folia Parasitol., 46: 123–131.Nagasawa, K. & Furusawa, S., 2006. New host and distribution records for Salvelinema salmonicola (Nematoda: Cystidicolidae), a parasite of fresh-water salmonids, in Japan. J. Grad. Sch. Biosp. Sci., Hiroshima Univ., 45: 9–14.Nagasawa, K., Urawa, S. & Awakura, T., 1987. A checklist and bibliography of parasites of salm-onids of Japan. Sci. Rep. Hokkaido Salmon Hatchery, (41): 1–75.Nagasawa, K., Katahira, H. & Tomiakawa, K., 2010. － 104－Swimbladder nematode from salmonids Kazuya Nagasawa, Toshihiro Hatama and Hirotaka KatahiraSalvelinema salmonicola (Nematoda, Cystidi-colidae): heavy infection in lacustrine sockeye salmon Oncorhynchus nerka from northern Ja-pan, with implication of the host’s feeding habits. Biogeography, 12: 25–28.Nakabo, T. (Ed), 2013. Fishes of Japan with picto-rial keys to the species, third edition. 2428 pp. Tokai Univ. Press, Hadano. (In Japanese).Okumoto, N., 1989. Salmo (Salmo) trutta. In Kawa-nabe, H. & Mizuno, N. (Eds), Freshwater fishes of Japan: 148–151. Yama-kei Publ., Tokyo. (In Japanese).Yamaguti, S., 1935. Studies on the helminth fauna of Japan. Part 9. Nematodes of fshes, I. Japan. J. Zool., 6: 337–386.（Received May 30, 2013; Accepted June 26, 2013）Swimbladder nematode from salmonids－ 105－Kazuya Nagasawa, Toshihiro Hatama and Hirotaka Katahira

Salvelinema salmonicola (Nematoda: Cystidicolidae) from lake-resident salmonids in western Honshu, Japan

Name not available

http://ir.lib.hiroshima-u.ac.jp/files/public/3/35285/20141016204827949591/Biogeography_15_103.pdf

Salvelinema salmonicola (Nematoda: Cystidicolidae) from lake-resident salmonids in western Honshu, Japan

Abstract

Similar works

Full text

Available Versions

Hiroshima University Institutional Repository

Name not available