Cymbella erhaiensis sp. nov., a new cymbelloid diatom species (Cymbellales, Bacillariophyta) from Yunnan Province, China

Cymbella erhaiensis sp. nov. is identified as a new species and described from stone surfaces in Lake Erhai, Dali Bai Autonomous Prefecture, Yunnan Province, China. A detailed morphological description of the new species is presented based on light and scanning electron microscopy. The new species is classified as Cymbella due to its strongly dorsiventral valves, the dorsal deflection of terminal raphe fissures, absence of stigmata, and the presence of apical pore fields. The new species is closely similar to C. sinensis but is distinguished from that taxon by stria density, shape and relative valve width of central area, and shape of areolae. Other similar taxa include C. subleptoceros, C. neoleptoceros, C. neoleptoceros var. tenuistriata, C. stigmaphora, with distinguishing characteristics including valve size, areola density and central area. The discovery of this new diatom species increases the known biodiversity of the southwest regions in China.