Spatial and temporal variation in rotifer community structure and the response to environmental factors among different water bodies in Guangzhou City

Abstract

Rotifers, a kind of essential plankton in aquatic ecosystem, is sensitive to environmental changes and playes an important role in food chain and microbial foodweb. Environmental factors and rotifer samples were collected from five type of water bodies (lake, pond, river, reservoir and estuary) in July and December, 2015, Guangzhou City. A total of 76 specie was identified, which belonging to 26 genera. The dominant species were Anuraeopsis fissa, in river in July and decreasing in December. The evenness index and the diversity index of river and estuary in winter were much higher than those in summer. Rotifer abundance ranged from 33 to 2625 ind./L. The abundances of rotifer in city lakes in summer were higher than those in winter, while opposite situation for the ponds. Analysis of similarities(ANOSIM) determined that the community structure was significant different among the different water bodies. These differences came from the abundance of dominant species, especially the river and lakes. Owing to the largest contribution rate of lakes made by Polyarthra vulgaris and that of river made by Trichocerca pusilla and A. fissa, the community structure of rotifers was significantly different. Statistical analysis showed that there was a positive correlation between chlorophyll-a concentrations and rotifer abundance. Redundancy analysis and ANOSIM analysis represented that P. vulgaris was more likely to dominated in lentic water, such as Lake Liuhua which contented of high chlorophyll-a concentration. A. fissa and Brachionus angularis were dominant in the Guangzhou segment of the Pearl River, the lotic waters with high total nitrogen and total phosphorus concentrations. In summary, the waters in Guangzhou City were eutrophic and measures should be taken to protect urban aquatic ecosystem.