LAUSR

Testate amoebae are an irreplaceable key component of microbial communities in many aquatic and soil ecosystems and well known as useful bioindicators. In the present work, testate amoebae compositions in different-type biotopes of freshwater waterbodies of North Vietnam were investigated for the first time. A total of 80 species and subspecies belonging to 12 genera and 8 families were identified from 105 samples collected in Suoi Hai, Xuan Khanh, Cam Quy, Ho Ba reservoirs, and Van Long wetland. Difflugia acutissima , D. brychtai , D. distenda , D. elegans teres , D. glans, and Awerintzewia cyclostoma were new records for Vietnam. Centropyxis aculeata , D. schurmanni, and D. elegans were the most common species in all types of biotopes including plankton, benthos, and periphyton. The results of two-way ANOVA showed statistically significant interaction effects of waterbodies and the type of biotopes on testate amoebae species richness per sample ( p  < 0.05). The simple effects analysis was performed to compare species richness per sample within studied waterbodies concerning the type of biotope and vice versa. A statistically significant difference ( p  < 0.001) in testacean mean species richness per sample was observed between aquatic macrophytes in periphytonic biotope. The results of NMDS and ANOSIM analyses showed statistically significant difference in the testate amoeba communities between studied waterbodies (ANOSIM r  = 0.16, p  < 0.001) and biotopes (ANOSIM r  = 0.29, p  < 0.001). The indicator value of species ( p  < 0.05) selected 17 indicator species including one for plankton, one for benthos, and 15 for periphyton. These findings provide new useful information for further paleoenvironmental researches using testate amoebae as bioindicators.