Meiofauna Distribution in Intertidal Sandy Beaches Along China Shoreline （18°-40°N）

In this study, the distribution pattern of meiofauna from nine sandy beaches at six latitudinal gradients along Chinese coast between 18 and 40°N was studied on their meiofauna abundance to examine the effect of latitudinal gradients. In general, meiofauna abundance was lower in four subtropical beaches in Xiamen （24°N） and Zhoushan （29°N） than that in other beaches. Meiofauna abundance differed little between tropical and temperate beaches. The taxonomic structure of meiofauna showed a dominance of nematode in colder area. The relative composition of turbellarians and polychaetes increased in warmer area. In addition to latitudinal gradient, salinity, oxygenation, sediment grain size affect also the meiofauna latitudinal distribution. As for horizontal distribu- tion, the highest meiofauna abundance was found in low tidal zone at tropical beaches, and in middle tidal zone at temperate beaches. The horizontal distribution of meiofauna was controlled by both physical and biotic factors including feeding and anthropogenic activities. Although meiofauna abundance exhibited a horizontal difference, the composition of meiofaunal main taxa was unanimous horizontally at all beaches at the same sampling latitude.