著者
Usio N 中田 和義 川井 唯史 北野 聡
出版者
日本陸水学会
雑誌
陸水学雑誌 (ISSN:00215104)
巻号頁・発行日
vol.68, no.3, pp.471-482, 2007 (Released:2008-12-31)
参考文献数
56
被引用文献数
12 14

2006年2月1日,北米原産のシグナルザリガニPacifastacus leniusculus(ウチダザリガニ,タンカイザリガニ)が特定外来生物の第二次指定種に選定された。本報では,特定外来生物の将来的な管理計画を念頭に置き,シグナルザリガニの国内での分布と防除の現状を報告する。シグナルザリガニは,1926年から1930年にかけて北米のコロンビア川流域から輸入された後,北海道や本州の天然水域に移植され,近年,急速に北海道はもとより本州でも分布を拡大している。2007年7月現在,シグナルザリガニは,北海道の東部,北部および中央部の地域,そして本州の3県(福島県,長野県,滋賀県)に分布している。外来生物法の施行以降,これまで北海道でのみシグナルザリガニの防除が行われ,2006年度には4湖沼,2007年度には河川を含む4水域においてカゴ罠やSCUBA器具を用いた素手による防除が実施されている。一方,滋賀県今津町では,個体群独自の標準和名(タンカイザリガニ)を重んじてシグナルザリガニを保護しようとする動きがある。最後に,シグナルザリガニ防除の問題点や今後の課題について議論する。
著者
熊川 真二 中田 和義 川井 唯史
出版者
日本ベントス学会
雑誌
日本ベントス学会誌 (ISSN:1345112X)
巻号頁・発行日
vol.66, no.1, pp.26-32, 2011-10-15 (Released:2012-10-11)
参考文献数
20
被引用文献数
1 1

Official documents and archives suggest that the alien crayfish Pacifastacus leniusculus (Dana, 1852) was introduced into Japan from North America on five occasions from 1926 to 1930, and populations have survived in Hokkaido, Nagano, and Shiga Prefectures. The chemical conditions and biological environment of an established habitat near their original a release point in Akashina, Azumino City, Nagano Prefecture, were surveyed on four occasions in 1998 and 1999. Water quality (pH, DO, BOD) and WT were recorded seasonally at each of eight stations, and crayfish and other aquatic macro-organisms were collected. Some predatory fishes (Oncorhynchus mykiss, Anguilla japonica, and Lepomis macrochirus) that might actively eat juveniles of P. leniusculus were recorded. Individual density of P. leniusculus was relatively low compared to its other habitats in Japan. Only 52 crayfish were collected during this study, on 19 of 32 sampling occasions (eight sites, four times each). The shape of the acumen and the species composition of ectosymbiotic crayfish worms (Annelida: Clitellata: Branchiobdellidae) can be used as tools to trace the origin of introduced of P. leniusculus in Japan. The present crayfish from Nagano Prefecture have a relatively short acumen, different from those of specimens from Shiga and Hokkaido Prefectures. Furthermore, the crayfish worm Xironogiton victoriensis occurs only on crayfish from Akashina, Nagano Prefecture. The dates of introduction of P. leniusculus in Nagano (1926, 1929) also differ from those for Hokkaido (1930) and Shiga Prefecture (1926). These findings suggest that the regional population of P. leniusculus in Nagano has a different origin than those in Shiga and Hokkaido, having originated from crayfish that were introduced independently from North America.
著者
浜野 龍夫 林 健一 川井 唯史 林 浩之
出版者
日本甲殻類学会
雑誌
甲殻類の研究 (ISSN:02873478)
巻号頁・発行日
no.21, pp.73-87, 1992-12-31
被引用文献数
4

Crayfish in Lake Mashu, Hokkaido, Japan, were captured with tangle nets in the summer of 1992. All specimens, 171 males and 517 females, had intermediate diagnostic character between two subspecies, Pacifastacus leniusculus leniusculus and P, l. trowbridgii. Although three very large individuals of unidentified crayfish were captured in this lake by poachers of trout in 1975 and 1985, there is no certain confirmation because of illegal samplings. One of the present authors took a chance to measure one of them, a fresh male crayfish with very large chelae, in 1975 when he was 11 years old and recorded only its giant size, i.e. 47 cm carapace length. However, the largest P. leniusculus collected in this study was 5.7cm in c. l. Neoteny may have occurred because there is no secondary sexual character on chelae of adult P. leniusculus males. This lake has no river. Age of the lake is estimated as about 2000 years old. Further, all species of fish and crustaceans in the lake were artificially introduced from other waters. Of crayfish, only P. leniusculus occurs and was introduced from Portland, Oregon, U.S.A., in 1930. From these, the unidentified gigantic crayfish seems to have been P. leniusculus grown to a giant size.