著者

吉田 竜矢 宇田川 貴大 日比野 拓

出版者

埼玉大学教育学部

雑誌

埼玉大学紀要. 教育学部 = Journal of Saitama University. Faculty of Education (ISSN:18815146)

巻号頁・発行日

vol.67, no.2, pp.341-351, 2018

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Hozoji pond is a natural habitat of the almost extinct aquatic carnivorous plant, Aldrovanda vesiculosa L., which the Government has designated as a special natural monument since 1966. Multifaceted research to save the endangered plant was urgently started from 2009. One of them, investigations of aquatic fauna of Hozoji pond was conducted for three years. The investigations revealed that an invasive alien species, Rana catesbeiana was dominant in the pond and it preyed upon A. vesiculosa. Here we showed four years of change in the aquatic fauna in the pond that was continuously investigated after the emergency research. Our data indicated that Palaemon paucidens, R. catesbeiana and Procambarus clarkii were still dominant in the pond. Small fishes, Pseudorasbora parva and Rhinogobius sp. were reduced in number. The Simpson index as a measurement of diversity was fluctuated between 0.313 and 0.802. The pH level of the pond was acidic. On the one hand the acidity is inhabitable for A. vesiculosa, but on the other hand it is not so appropriate for the small fishes. The continuous activity of both exterminating R. catesbeiana and monitoring aquatic fauna in the pond could be necessary in the future.