AN ECOLOGICAL STUDY ON THE MOLLUSCA IN MANGROVE AREAS IN THE ESTUARY OF THE JIULONG RIVER

Based on the surveying data obtained in February, May, August and Nove mber, 1987, the ecology of Mollusca in mangrove areas in the estuary o f the Jiulong River in Fujian Province was studied. The results are as follows: There are 52 species of Mollusca in the areas, and species a nd abundance distribution increase with salinity. Biomass and density average 7.99 g m(2) and 25 ind, m(2) respectively, with higher values in autumn and winter, and lower in spring and summer. Vertical distrib ution of biomass is highest in high tide zones and lowest in low tide zones, and density is highest in mid-tide zones and lowest in low tide zones. The relationship between the distribution of Mollusca and the environmental factors are discussed.