Abstract
Cobbled shores in subtropical Japan are small and disturbed by sand transported from terrestrial runoff. How benthic organisms live in such a harsh environment has been seldom studied. On a cobbled shore at Ishigaki Island, the present study investigated the life-history traits of the gastropod, Nerita squamulata Le Guillou 1841. Seasonal quadrat samplings showed that the neritid density decreased when and where sand covered cobbles, indicating impact of sand on the neritid. Monthly frequency histograms of the shell width suggested that the neritid lives less than 2 years and recruits as individuals of 1-4 mm shell width in both May-August and February. With the possible short longevity and frequent recruitments, the neritid population may quickly recover after the disturbance by sand.
