Studies on the Abundance and Species Distribution of Free-living Marine Nematodes in Sandbeach, Xiamen Island

The species distribution and abundance of nematodes in a beach were sampled for 5 times in a 8 months period. The beach is a sandflat, covered with a thick bed of mud. Results showed that the highest abundance of nematodes was (2.67±0.39)×10 6 ind/m 2, and the lowest was (1.61±0.17)×10 6 ind/m 2. However, difference in abundance was not significant between the five samples (P0.01). Most of the nematodes were concentrated in the up-level, which shows that the nematodes abundance decreases with the depth. The vertical distribution type did not changed much during the 8 months. The kind of species in the up-level of samples only changed a little in the 8 months, but dramatical change occurred in the deeper layer. Discussion was made for the results with comparing to other published data.