A new species of Gomphosinica (Bacillariophyta) from Lugu Lake, Yunnan Province, SW China

Abstract

A new Gomphosinica species is described here as new to science. Based on its small and narrowly linear-clavate valves, slightly protracted or not protracted, rounded headpole, and rounded footpole, as well as irregularly-shaped central area, this species is readily distinguishable from its congeners. SEM observations show this species has one stigma in the central area; the external opening of the stigma is small and round, while the internal opening has a hooded structure with several small perforations. Also evident is the presence of biseriate striae composed of small and round areolae. This observation is interesting since most Chinese members of the genus have triseriate striae. The raphe structure is also unique, since the external distal raphe end terminates far short of the valve terminus at both ends. At the footpole, the raphe does not bisect the apical pore field. This species was found from Lugu Lake, Yunnan Province, China, and was named as Gomphosinica lugunsis Liu, Kociolek, You & Fan sp. nov. Differences with other taxa and the biogeographic distribution of this genus are discussed.