著者

小枝 圭太 興 克樹 米沢 俊彦 久米 元

出版者

鹿児島大学

雑誌

鹿児島大学水産学部紀要 = Memoirs of Faculty of Fisheries Kagoshima University (ISSN:0453087X)

巻号頁・発行日

vol.65, pp.21-26, 2016

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The fresh water species Green Swordtail Xiphophorus heller Heckel, 1848, endemic to central and northern America, was introduced to Japanese waters in the 1960's, established populations being recorded on Kume-jima island and Okinawa-jima island (Okinawa Prefecture), and in Yamanashi Prefecture. A single specimen (39.9 mm SL) of Green Swordtail, collected from the Handa River in May 2011, was the first record of the species from Amami-oshima island (one of the Satsunan Islands). Although the population increased hugely over the following years, it decreased significantly in winter 2015/2016, during which record low temperature levels occurred, only to recover within six months. The morphology of specimens from Amami-oshima island are described in detail, and distributional records of the species and recent population status on Amami-oshima island are discussed.