[Polychaete community in mangrove and salt marsh in Zhangjiang River Estuary, Fujian Province of East China].

In order to understand the community structure of polychaete in different botanic habitats in Zhangjiang River Estuary, an investigation was conducted in the habitats of Kandelia candel, Aegiceras corniculatum, Spartina alterniflora, and Avicennia marina in four seasons, 2010. A total of 15 polychaete species were recorded, and 6 species including Eteone delta, Namalycastis abiuma, Paraleonnates uschakovi, Polydora ciliata, Capitella capitata, and Mediomastus californiensis were found in the four habitats and four seasons. The density, biomass, richness index, evenness index, and diversity index of the polychaete had no significant differences among seasons but significant differences among habitats, and the dominant species of polychaete in S. alterniflora habitat differed from that in the other three mangrove habitats. Pearson correlation analysis showed that in the mangrove and salt marsh, there were no significant correlations between the polychaete parameters (density, biomass, richness index, evenness index, and diversity index) and the environmental factors (sediment temperature, salinity, total organic carbon, and total nitrogen), except that the species number of polychaete had significant correlation with sediment temperature due to the common species of polychaete such as Capitella capitata, Mediomastus californiensis, and Namalycastis abiuma in the mangrove and salt marsh in Zhangjiang River Estuary being of eurytherm and eurysalinity, and resistant to high organic matter content.