著者

向井 貴彦 二村 凌 丹羽 大樹 後藤 暁彦 三輪 直生 石塚 航 矢追 雄一 高木 雅紀

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.62, no.2, pp.149-156, 2015-11-05 (Released:2018-03-26)

参考文献数

35

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Japanese char Salvelinus leucomaenis, red-spotted masu salmon Oncorhynchus masou ishikawae, hybrid individuals were collected from a tributary of the Ibigawa River, Gifu Prefecture, Japan. The char and hybrids were mainly distributed in the headwater area where eyed eggs of red-spotted masu salmon are released in each year. Principal component analysis (PCA) of the morphological features of parental and hybrid individuals indicated that hybrid body shape was similar to that of char. Partial nucleotide sequences of mitochondrial DNA indicated the female parental species to be red-spotted masu salmon, without exception. Genotyping of three loci of short interspersed repetitive elements (SINE) of inserted alleles showed all hybrid individuals to be F1, with no evidence of backcrossing. These results indicated that the introduced red-spotted masu salmon hybridized with male char, with a high survival rate of sterile F1 offspring.

著者

後藤 暁彦 黒木 真理 森田 健太郎

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.67, no.2, pp.241-245, 2020-11-05 (Released:2020-11-14)

参考文献数

20

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A non-native brown trout Salmo trutta (407 mm in fork length, 717 g in body weight) was collected from the Otsukushinai River, southern Hokkaido, Japan, in 2019. This specimen was an immature male (0.4 g in gonad weight). The otolith Sr:Ca ratio profile and annual rings suggested that the specimen had migrated to the sea at the age of 4+ years and ascended the Otsukushinai River in the year of the seaward migration. This study is the first record of invasion of anadromous brown trout through the sea in Japan.

著者

加藤 柊也 丸山 智朗 乾 直人 後藤 暁彦 鈴木 寿之 瀬能 宏

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

pp.19-031, (Released:2020-02-28)

参考文献数

19

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Eighteen specimens of the pipefish Microphis retzii were collected from several rivers on Iriomote and Ishigaki Islands (Yaeyama Islands, Ryukyu Islands, Japan) from 1990 to 2019. The records from Iriomote Island, including variously sized specimens plus brooding males over multiple years, suggest established settlement of the species. The records from Ishigaki Island, being the first specimen-based records of the species from that locality, are suggestive of a new settlement. Accordingly, M. retzii should be treated as a Japanese resident species, rather than one subject to abortive migration, making them eligible for evaluation of red lists in Japan.