著者

久保田 信

出版者

日本生物地理学会

雑誌

日本生物地理学会会報 (ISSN:00678716)

巻号頁・発行日

vol.61, pp.85-88, 2006-12-30

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A mature medusa of Laodicea undulata collected at Okinawa Island, Japan, displayed life cycle reversion, i. e. direct transformation to the polyp stage. The morphology of the reverted polyp is briefly described. This species appears to be the second potentially immortal animal in the Metazoa, after another hydromedusa Turritopsis nutricula, although the present polyp colony, comprising a maximum of 4 zooids despite a wide extension of stolons, degenerated after 5 months without producing a new generation of medusae.