Pneumodermopsis paucidens in the North Sea

Abstract

Clione limacina Phipps is the only gymnosomatous pteropod normally found in the North Sea, but Pneumodermopsis ciliata Gegenbaur has been recorded occasionally from Shetland waters1,2. In 1960, however, P. paucidens Boas was recognized for the first time in the North Sea, where it appeared in collections taken with the small Plankton Indicator3 and the Continuous Plankton Recorder4, both sampling in the upper 10 m. It was first recorded in mid-June to the east of the Orkney Islands and, at about the same time, off the north-west coast of Ireland and to the south of Iceland. Thereafter it was found over a wide area (Fig. 1) until early December, with peak numbers of about 10 per m.3 at the beginning of September. Previously this species has been recorded only from the North Atlantic and off the coast of Ireland5.