[Community structure of rotifer in Mingzhu Lake of Chongming Island, Shanghai].

A comprehensive survey on the quantitative distribution, community structure, species composition, dominant species, and species diversity of rotifer was conducted in the Mingzhu Lake of Chongming Island, Shanghai in January-December, 2008. There were 27 species of rotifer in the Lake, belonging to 8 families and 11 genera. The dominant species were Polyarthra trigla, Trichocerca pusilla, Brachionus calyciflorus, Brachionus forficula, and Philodina sp. The rotifer had an average annual density of (1505.42 +/- 1304.63) ind x L(-1), and an average annual biomass of (2.012 +/- 2.146) mg x L(-1). The Shannon-Wiener diversity index, evenness index, and richness index of rotifer community in the Lake were relatively low, while the dominance index was rather high, indicating that the community structure of the rotifer was unstable. The E/O value wes 1.61 +/- 1.46 on average, and the Q(B/T) values wes 1.23 +/- 0.84 on average. Water temperature was the main factor affecting the rotifer distribution. Biological assessment of water quality suggested that the Mingzhu Lake was on eutrophication.