Two new species of the diatom genus Cymatopleura, Cymatopleura aquastudia and Cymatopleura xinjiangiana, that have torsion about the apical axis of the valves, are reported from Xinjiang Region, China, using light and scanning electron microscopy. The valves of Cymatopleura aquastudia sp. nov. exhibit torsion about the apical axis, are heteropolar, and are slightly constricted at the margin in the middle of the valves. These characters differentiate it from morphologically similar taxa in the genus, e.g. C. solea (Brébisson) W. Smith and C. spiralis Behning in Rauschenbach et Behning. The valves of Cymatopleura xinjiangiana sp. nov. also exhibit torsion about the apical axis, but are small and have curved ridges at both ends and rounded apices that are protracted at the wider ends. These features distinguish C. xinjiangiana from C. cochlea Brun and C. elliptica f. spiralis Boyer. These two new taxa help to demonstrate the unique nature of the freshwater diatom flora from Xinjiang Region, China. |
