Expansion of the barnacle Austrominius modestus (Darwin, 1854) (cirripedia, Thoracica, Balanidae) into Scandinavian waters based on collection data and niche distribution modeling

The barnacle Austrominius modestus, native of New Zealand and Australia was introduced to the South of England around 1943 and has since spread to most coastal waters in Western Europe, including the southern North Sea. Apart from an ephemeral incursion into the Danish Wadden Sea in 1978, since 2010 it has established permanent populations capable of reproduction along the North Sea coast of the Jutland peninsula, the Limfjord, the north-western Kattegat, and the Skagerrak. It has probably invaded Danish waters by pelagic larvae originating in the German Wadden Sea. The species has since spread to other Danish localities, likely following the prevailing currents, but other means, as for instance transport by vessels, are possible. The barnacle inhabits stones, stone-reefs, mollusk shells, and live shore crabs in shallow waters. Based on hydrographical data from its native and recently invaded areas, we predict its future distribution to extend to most coasts of continental Europe except for brackish waters (< 20 PSU), and the Arctic seas. The northernmost distribution limit may include the Lofoten Islands of NorwaypublishedVersio

本州北部の北太平洋沿岸の短尾類と異尾類に寄生する根頭類と等脚類

北太平洋に面する岩手県三陸町吉浜湾船作海岸の潮間帯から採集した短尾類と異尾類に寄生する根頭類と等脚類を調べた. イワガニにヤツフクロムシ(新称)Sacculina yatsui, イソガニにフクロムシ属の1種Sacculina sp., ホンヤドカリ属の1種Pagurus maculosus(新宿主)にナガフクロムシPeltogaster paguri, ホンヤドカリ(新宿主)・テナガホンヤドカリ・P. maculosus(新宿主)にフサフクロムシPeltogasterella gracilis, ホンヤドカリとP. maculosus(新宿主)にヤドカリノハラヤドリAthelges takanoshimensisを認めた. これらの寄生虫は本海域から初記録であり, その出現状況, 形態, 分布を記述した.Four species of Rhizocephala were found on crabs from the intertidal rocky shore of Sanriku, northern Honshu: Sacculina yatsui Boschma, 1936 from Pachygrapsus crassipes; Sacculina sp. from Hemigrapsus sanguineus; Peltogaster paguri Rathke, 1842 from Pagurus maculosus (new host); and Peltogasterella gracilis (Boschma, 1927) from Pagurus filholi (new host), P. maculosus (new host) and P. middendorffii. The bopyrid isopod Athelges takanoshimensis Ishii, 1914 also occurred on P. filholi and P. maculosus (new host). These parasitic crustaceans are recorded for the first time from the Pacific coast of northern Honshu