THE SUPRABENTHIC CRUSTACEAN FAUNA OF THE INFRALITTORAL FINE SAND COMMUNITY FROM THE BAY OF SEINE (EASTERN ENGLISH-CHANNEL) - COMPOSITION, SWIMMING ACTIVITY AND DIURNAL-VARIATION

The suprabenthic fauna of a station located in the outer part of the e stuary of the Seine (Eastern English Channel) was sampled with a modif ied Macer-GIROQ suprabenthic sledge. Thirty-eight hauls were collected in two series of hourly sampling; they provided a first quantitative description of the suprabenthic crustacean fauna from this area. Speci es composition of the fauna, swimming activities and diurnal vertical migrations of the main species were studied. A total of forty-six crus tacean species were collected. Mysids and cumaceans were the most abun dant species of the fauna. The dominant species were Schistomysis kerv illei, Mesopodopsis slabberi, Diastylis bradyi and Pseudocuma longicor nis. All principal species of the fauna regularly performed a nocturna l vertical migration.