RECRUITMENT AND GROWTH OF THE BLUE-RAYED LIMPET, HELCION PELLUCIDUM (L.), IN SOUTH EAST IRELAND

This account reports on recruitment, growth and population structureof the macroherbivorous gastropod Helcion pellucidum (L.) onan exposed rocky shore in S.E. Ireland, with particular referenceto the pellucidum form. Recently settled Helcion spat were foundinitially on living crustose lithothamnia in pools and on openrock, on the lower shore, during February-April and subsequentlyrecruited to macro-algal fronds. By May they were found in abundanceon Mastocarpus stellatus and Laminaria spp. Helcion was markedlyseasonal in its occurrence on Mastocarpus, being most abundantduring May-August. A complementary pattern was evident on growingHimanthalia receptacles, with limpets abundant from July onwards.It is suggested that Helcion may migrate from Mastocarpus toHimanthalia as they grow. Data on growth rates are presentedfor Helcion in the various habitats studied. Growth rates werehighest on the Laminaria spp. (Received 21 February 1992; accepted 8 June 1992)