Temporal and Spatial Variations in the Species Composition, Distribution, and Abundance of Protozoa in East Dongting Lake, China

Abstract

Investigations of protozoa were carried out during four surveys of East Dongting Lake, China. A total of 160 protozoan species belonging to 7 1 genera was identified, of which 53 were flagellates, 37 sarcodines, and 70 ciliates. Among them, Peritrichida (32.6% of frequency), Arcellinida (16.2%), Volvocales (13.6%), Peridiniales (13.1%), and Chrysomonadales (9.1%) were the main groups and contributed to 84.5% of the overall species. Ciliates were mainly composed of sessile species and small species. The total protozoan abundance varied from 2,400 cells L" to 20,250 cells L". The highest protozoan abundance occurred in spring; the lowest number was in autumn. The highest abundance of ciliates occurred in spring and winter, whereas flagellates developed the highest abundance in summer and autumn. Pearson correlation analysis and linear regressions indicated that chlorophyll a and water velocity were the main factors affecting temporal and spatial variations of the protozoan abundance.

Taxonomy and phylogeny of the freshwater tintinnid Tintinnopsis tubuformis Chiang, 1956 (Ciliophora, Oligotrichea) and a proposed synonymization of T. longa nom. corr. Chiang, 1956

“…The scale bar corresponds to 0.06 substitutions per 100 nucleotides our thorough literature surveys could not unearth records from outside of China or Japan. In China, the species were reported from the Yangtze River system (Chiang, 1956;Wang et al, 1988;Wu et al, 2007) and the city of Changde (Jiang, 2006). In Japan, only the short morphotype of T. tubuformis was reported from Lake Kasumigaura (Takamura et al, 2000).…”