A new freshwater Psammodictyon species in the Taihu Basin, Jiangsu Province, China

We describe a new species of diatom, Psammodictyon taihuensis sp. nov., collected from the Taihu Basin, Jiangsu Province, China. There are several features of this diatom that suggest it should be included in the genus Psammodictyon, notably the possession of panduriform valves characterized by a longitudinal fold near the apical axis, coarsely areolate striae, and a keeled raphe system present on the valve margin. This species is distinct from others in the genus by its small size, being only 16.5-25.0 μm long and 10.0-12.5 μm wide in the central region, and with the widest valve being 10.5-13.5 μm in width. There are 8-11 distinct fibulae per 10 μm and the striae are composed of 18-22 coarse areolae per 10 μm. This is the first report of a freshwater member of the genus Psammodictyon in China, which expands the known geographical and ecological distributions of the genus and enhances our understanding of freshwater diatom diversity in China.