Seasonal variations of rotifer communities in three climatic zones: effects of environmental parameters on changes of functional groups

In this study, the annual changes of rotifer communities were observed in six lakes belonging to tropical, subtropical, and warm temperate zones. Rotifers were classified into different functional groups based on the morphology of the corona and trophi. The abundance and biomass of each functional group were compared between climatic zones, and the driving environmental factors were analyzed. Analysis of similarities (ANOSIM), and similarity percentage analysis (SIMPER) indicated distinct separation in rotifer community structure between the three climatic zones. The subtropical zone showed more functional groups, higher abundance and biomass of dominant functional groups than tropical and warm temperate zones. Asplanchna abundance and water transparency were considered as the major factors affecting rotifer functional groups in all the three climatic zones. Chlorophyll a content (Chl-a) was more important in subtropical and warm temperate zones than in tropical zone. Water temperature mainly affected rotifer functional groups in warm temperate and tropical zones, but showed less effects in subtropical zone. In addition, NO2−-N content was an important factor in warm temperate zone, but not in subtropical and tropical zones. Overall, classification of functional groups could be a useful method to investigate the changes of rotifer community structure in different climatic zones.