Aggregation of the littorinid snail Littorina unifasciata in New South Wales, Australia

Abstract

Quantifies aggregation by L. unifasciata on different shores, levels on the shore and in different microhabitats. The use of patches of habitat of different size during low tide and high tide is also examined. Aggregation was variable from time to time and place to place and individual snails did not show a consistent tendency to aggregate on different occasions. Snails were less aggregated when they spread out to feed during high tide than when emersed during low tide, but this was only found at very small spatial scales because snails do not move far to feed. Therefore, the cues that operate to cause the snails to aggregate in some patches and not others appear to be operating at the scale of centimetres, rather than metres. -from Author