Abstract:

To explore the status of macrozoobenthic communities and their response to ecological changes in Lake Taihu, we carried out a quarterly investigation on macrozoobenthos between February 2007 and November 2008. We recorded 40 species from 19 families, 7 classes and 3 phyla. Mean density and biomass varied largely among the 30 sampling sites. The highest mean density of macrozoobenthos occurred in Meiliang Bay, Zhushan Bay and river mouth, and communities were dominated by Tubificidae. Mean biomass was highest in Gonghu Bay, Western region, East Taihu and East Bays, these sites were dominated by Mollusca. Limnodrilus hoffmeisteri, Rhyacodrilus sinicus, Corbicula fluminea, Bellamya aeruginosa, Tanypus chinensis and Gammarus sp. were the dominant species in Lake Taihu. Cluster analysis and one-way analysis of similarity (ANOSIM) classified the 30 sites into three groups with different macrozoobenthic communities (P < 0.05). K-dominance curves, Shannon-Wiener and Pielou indices indicated that species richness and evenness were highest in East Taihu and East Bays, dominated by Gastropods. Communities in Meiliang Bay, Zhushan Bay and river mouth had low species diversity and were dominated by L. hoffmeisteri and R. sinicus. Gonghu Bay, Central region and Western region contained intermediately diverse communities dominated by C. fluminea. Our results suggest that trophic status, habitat types and macrophytes are important factors regulating macrozoobenthic communities in Lake Taihu.

Key words: Tubificidae, Mollusca, functional feeding groups, spatial distribution pattern, eutrophication