VERTICAL-DISTRIBUTION, MORPHOLOGY AND DIET OF PROBOSCIDACTYLA-STELLATA (CNIDARIA, LIMNOMEDUSAE) IN LOUGH-HYNE MARINE NATURE-RESERVE, CO CORK, IRELAND

The vertical distribution, morphology and diet of Proboscidactyla stel lata (Cnidaria: Limnomedusae) were studied in Lough Hyne over a two ye ar period. Vertical hauls of four depth strata, 40-30 m, 30-20 m, 20-1 0 m and 10-0 m, were taken monthly and at 4 h intervals for a period o f 48 h in July and 24 h in September 1994. Proboscidactyla stellata wa s largely concentrated in the lower 20 m of the water column reaching a maximum of 21 m(-3) at 30-20 m depth in June 1993. An oxythermocline occurred at 25-30 m depth in the summer and autumn months of 1993 and affected the vertical distribution of the medusae. Six morphs of the species, varying in the number of gonads, were found in the lough. Biv alve veligers, which P. stellata actively selected formed 83% of the d iet.