著者

角田 裕志 土井 真樹絵 大平 充 満尾 世志人 千賀 裕太郎

出版者

「野生生物と社会」学会

雑誌

野生生物保護 (ISSN:13418777)

巻号頁・発行日

vol.13, no.2, pp.59-66, 2012

参考文献数

26

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We investigated fish fauna in the littoral areas of Lake Saiko and Shojiko, Yamanashi Prefecture, Central Japan and compared them with those in previous studies. Two species have newly appeared in each lake: <i>Oncorhynchus masou masou</i> (Salmonidae) and <i>Pseudogobio esocinus esocinus</i> (Cyprinidae) in Lake Saiko and two Gobiidae species, <i>Tridentiger brevispinis</i> and <i>Gymnogobius urotaenia</i>, in Lake Shojiko. Three of these fishes are non-indigenous Japanese fishes and may have been introduced unintentionally in recent years, whereas <i>O. masou masou</i> was stocked for fishing by fishery managers of Lake Saiko. In Lake Saiko, the fish species composition has greatly changed and a goby, <i>Rhinogobius</i> sp. OR, has been dominated by another goby, <i>T. brevispinis</i>, during the past decade. In Lake Shojiko, species composition and dominant species has not changed and a goby, <i>R.</i> sp. OR, was the dominant benthic fish in littoral areas. However, we found that <i>T. brevispinis</i> has also invaded Lake Shojiko recently and greatly increased in number during the study period. The results indicated that unintentional introduction of non-indigenous fish species may have frequently occurred with fish stocking in recent years.