A new species of Navicula (Bacillariophyta; Naviculaceae) from Yunnan Province, China

During analyses of surficial sediments from Lake Fuxian in Yunnan Province, Southwest China, Navicula fuxianensis sp. nov. was recorded and described by light and scanning electron microscopy analysis. The new species is characterized by a lateral, slightly undulate raphe and lineolate striae, as well as variously shaped areolae and an internally-elevated raphe system. Navicula fuxianensis sp. nov. shares features with other species in this genus, similar to N. gongii in valve outline and stria arrangement, respectively. However, the species can be easily distinguished from taxa which it resembles by the density of striae and lineolae, as well as the structure of the central area and areolae. The new Navicula species from Lake Fuxian has unique sets of characters that distinguish it from all previously described Navicula species. Brief notes on the associated diatom flora and its ecological preferences are added.