FIRST REPORT OF THE PRESENCE OF ACARTIA-MARGALEFI (COPEPODA, CALANOIDA) IN SOUTHAMPTON WATER AND HORSEA-LAKE, UK

Acartia margalefi is recorded for the first time in British waters, wh ere it is found to be an important copepod in the mesozooplankton comm unity structure of Southampton Water and Horsea Lake. Within the genus Acartia, this species occurs all through the annual cycle. Abundance is higher in the upper estuary, where the range of temperature and sal inity is relatively wider over the year. It is clear that A. margalefi is an estuarine species which can tolerate a significant range of tem perature.