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論文(リポジトリ)

論文(リポジトリ)
西垣, 孝治 ; Nishigaki, Koji ; 西山, 桂一 ; Nishiyama, Keiichi
出版情報: Fauna Ryukyuana.  68  pp.5-7,  2023-10-12.  琉球大学資料館 (風樹館)
URL: http://hdl.handle.net/20.500.12000/0002020025
概要: コエビ下目,テッポウエビ科,オハグロテッポウエビ Metabetaeus minutus (Whitelegge, 1897) を 2018 年 1 月に沖縄県本部町の洞窟地下水域から採集した.沖縄島初記録を報告すると共に,採集地の環境につ いて報告する .
An alpheid shrimp, Metabetaeus minutus (Whitelegge, 1897) (Caridea: Alpeidae) is collected from an anchialine cave in Okinawajima Island, Ryukyu Archipelago, Japan. The present report represents the first record of the species from the island. This report also notes the environmental features of the habitat.
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2.

論文(リポジトリ)

論文(リポジトリ)
西山, 桂一 ; 西垣, 孝治 ; Nishiyama, Keiichi ; Nishigaki, Koji
出版情報: Fauna Ryukyuana.  56  pp.13-15,  2020-07-03.  Ryukyu University Museum, Fujukan — 琉球大学資料館 (風樹館)
URL: http://hdl.handle.net/20.500.12000/46857
概要: A cave-dwelling spider, Coelotes troglocaecus Shimojana & Nishihira, 2000, was newly recorded from Amuji-gama Cave on Mi yagi Island, located off Katsuren Peninsula, Okinawa Island, central Ryukyus, Japan, after previously being reported from seven caves on Okinawa Island. This species is characterized by cave-adapted white body color and lack of eyes. This spider has been found from locations where whitened homopteran insects inhabit.
論文
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3.

論文(リポジトリ)

論文(リポジトリ)
西山, 桂一 ; 島田, 拓 ; 吉田, 譲 ; 田村, 常雄 ; Nishiyama, Keiichi ; Shimada, Taku ; Yoshida, Yuzuru ; Tamura, Hisao
出版情報: Fauna Ryukyuana.  52  pp.1-9,  2019-11-24.  Ryukyu University Museum, Fujukan — 琉球大学資料館 (風樹館)
URL: http://hdl.handle.net/20.500.12000/46840
概要: The harvestman species, Parabeloniscus caudatus Suzuki, 1973 (Opiliones, Epedanidae), has been recorded from Okinawa-jim a Island, Miyagi-jima Island and Ikei-jima Island of the central Ryukyus, Japan. This species is considered to be highly dependent on cave environments (Shimojana 1978; 1979). Our survey found new habitats of P. caudatus from Amami-oshima, Tokunoshima and Okinawa-jima islands in the central Ryukyus, Japan. An unidentified Parabeloniscus species has previously been reported from Amami-oshima and Tokunoshima islands, and our study confirmed for the first time that P. caudatus is distributed on these islands. We also found the species under stones in the forests outside caves. A previous study reported the presence of eyeless individuals (Shimojana 1979). The current study also found eyeless individuals from two separate caves.
論文
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4.

論文(リポジトリ)

論文(リポジトリ)
西山, 桂一 ; Nishiyama, Keiichi
出版情報: Fauna Ryukyuana.  47  pp.11-17,  2018-12-10.  Ryukyu University Museum, Fujukan — 琉球大学資料館 (風樹館)
URL: http://hdl.handle.net/20.500.12000/46813
概要: 沖縄島の7洞窟からヒメユリサワガニGeothelphusa tenuimanus (Miyake & Minei, 1965),オキナワオオサワガニG. grandiovata Naruse, Shokita & Ng, 2006,サカモト サワガニG. sakamotoana (Rathbun, 1905)の3種のサワガニ類が確認された.今回の調査では,洞内でのヒメユリサワガニの放仔のほか,ヒメユリサワガニとオキナワオオサワガニの小型個体が見られるなど,洞内での繁殖に関わる生態が観察された.また,ヒメユリサワガニは体色に個体変異が見られ,大宜味村の洞窟では体色が著しく白化した個体も観察された.また同じ洞窟内では色彩の傾向が類似しており,遺伝的に分化している可能性があった.
Three freshwater crab species, Geothelphusa tenuimanus (Miyake & Minei, 1965), G. grandiovata Naruse, Shokita & Ng, 2006, and G. sakamotoana (Rathbun, 1905) were observed from seven caves in Okinawa Island, Ryukyu Islands, Japan. Some reproductive evidence in the caves, such as juvenile-releasing G. tenuimanus and the presence of young individuals of G. tenuimanus and G. grandiovata, were observed. The coloration of G. tenuimanus varied individually, but individuals from the same cave tended to have similar color pattern; and some individuals from Ogimi Village had white body color, suggesting possible genetic isolation.
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