POPULATION-STRUCTURE AND RECRUITMENT OF THE INTERTIDAL GASTROPOD MELARHAPHE NERITOIDES (L.) ON AN EXPOSED ROCKY SHORE ON THE SOUTH COAST OFIRELAND

The population structure and recruitment of the marine intertidal gast ropod Melarhaphe neritoides (L.) were examined at a series of vertical stations on the exposed rocky shore at Carnsore Point, Co. Wexford, d uring summer. The data show that a settlement occurred during May/June , and suggest that it extended throughout most of the eulittoral zone. No recruitment was observed on open rock in either the Verrucaria or yellow lichen zones. Growth of the recent recruits appeared to be fast er lower on the shore. Mean adult size was largest among the snails lo cated highest on the shore and decreased downshore to the top of the e ulittoral zone. Mean size then increased further downshore.