著者

大橋 慎平 千葉 悟 清藤 秀理

出版者

日本魚類学会

雑誌

魚類学雑誌 (ISSN:00215090)

巻号頁・発行日

pp.18-029, (Released:2018-09-25)

参考文献数

14

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An increase in gill raker numbers in skipjack tuna (Katsuwonus pelamis) was observed during the development of juvenile and young stages (26–187 mm in standard length (SL)). Examination of 104 individuals showed obvious increments in number with growth, until 80–100 mm SL. Subsequently, numbers increased slowly (to 59 in the largest specimen), indicating that gill raker development in skipjack tuna is slower than in other scombrid fishes, such as Thunnus. However, gill raker numbers in juvenile and young skipjack tuna stages remain a useful taxonomic character.

著者

大橋 慎平 今村 央 矢部 衞

出版者

一般社団法人 日本魚類学会

雑誌

魚類学雑誌 (ISSN:00215090)

巻号頁・発行日

vol.60, no.2, pp.111-116, 2013-11-05 (Released:2015-12-26)

参考文献数

23

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Two specimens (131.5 and 147.0 mm in standard length) of the Gelatinous Blindfish Aphyonus gelatinosus Günther, 1878, collected from southern Japan (Kumano Sea and near the Tori Island, part of the Izu Island chain), were found among preserved specimens held by the Department of Natural Science, Faculty of Science, Kochi University, Kochi, Japan and National Museum of Nature and Science, Tsukuba, Japan. Aphyonus gelatinosus is recognizable in having only a single pelvic fin ray, high numbers of dorsal fin rays (92–118) and caudal vertebrae (46–55), few long gill rakers (3–4), and short predorsal length (26.5–30.5% SL). This species and genus is known from the Pacific Ocean, but not from the north Pacific including Japanese waters. Thus, these specimens are a new record of both the genus Aphyonus and A. gelatinosus for Japan.

著者

大橋 慎平 永野 優季 加藤 克 河合 俊郎 矢部 衞

雑誌

北海道大学水産科学研究彙報 (ISSN:13461842)

巻号頁・発行日

vol.64, no.2, pp.55-69, 2014-07-31

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Approximately 3,500 fish specimens were transferred from the Faculty of Agriculture, Hokkaido University to the Fisheries Science Center, Hokkaido University Museum (HUMZ). The authors identified fishes from at least 16 orders, 57 families, 109 genera and 145 species. Although most specimens were collected around Japanese waters, several species were collected from other areas, e.g., Eleginops maclovinus (Eleginopsidae) from Chile and Luciocephalus pulcher (Osphronemidae) from India.

著者

中田 和義 永野 優季 大橋 慎平 河合 俊郎 大高 明史

出版者

日本ベントス学会

雑誌

日本ベントス学会誌 (ISSN:1345112X)

巻号頁・発行日

vol.69, no.2, pp.90-94, 2014-12-31 (Released:2016-02-06)

参考文献数

24

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In Lake Akan, Hokkaido, northern Japan, the local population of the native and endangered Japanese crayfish Cambaroides japonicus (De Haan, 1841) is extinct, whereas the signal crayfish Pacifastacus leniusculus (Dana, 1852), an invasive species from North America, has become established and rapidly increased. This study provides information about specimens of C. japonicus preserved by Dr. Saburo Hatta from the lake in 1872. The six specimens (two males and four non-ovigerous females) are valuable evidence of C. japonicus formerly inhabiting Lake Akan. The body sizes of the specimens were 24.4–29.5 mm in carapace length and 55.7–67.4 mm in total length, and the estimated age of the largest specimen was ten years, indicating that Lake Akan of that time provided a suitable habitat. Twenty-two ectosymbiotic crayfish worms (Annelida, Clitellata, Branchiobdellida) were found attached to the specimens. Three branchiobdellidan species were identified: Cirrodrilus cirratus Pierantoni, 1905, C. inukaii (Yamaguchi, 1934) and C. megalodentatus (Yamaguchi, 1934). This is the first record of the latter two species from Lake Akan.