Macrofaunal distribution on a sandy shore

Abstract

This paper examines the distribution of macrobenthos on a sandy shore at Morib. From faunal samples taken along transects from upper to lower shore, the most abundant organisms are the soldier crab, Dotilla myctiroides, and two bivalves, Tellina philippinarum and Solen regularis. They occur in varying denisities throughout the transects: D. myctiroides are most abundant near the upper shore where their density may exceed 1000 m², T. philippinarum are found predominantly in the mid-tidal regions while S. regularis are found in high densities near the lower shore. Polychaetes from the four families (Chaetopteridae, Eulepethidae, Glyceridae and Oniphidae) are also common. A chaetopterid, Sasekumaria selangora and a porcellanid crab associated with it occur in large numbers at the lower shore while the other polychaetes show irregular distributions along the beach. The distribution patterns and some factors affecting them are discussed and the importance of some of the organisms as a food source for marine fishes is reviewed.