Prestauroneis genkalii-a new diatom species (Bacillariophyceae: Stauroneidaceae) from Southeast Asia

We present light and scanning electron microscopical observations on one new species of Prestauroneis from Vietnam. The new species, Prestauroneis genkalii Glushchenko. Kulikovskiy & Kociolek sp. nov., is described on the basis valve outline, shape of the apices, as well as striae and areolar densities. Morphology of Prestauroneis species, especially with respect to valve outline, is discussed. P genkalii sp. nov. possesses all of the typical morphological features for the genus, including uniscriate striae covered by internal hymenes, a pscudoseptum at each apex and distal raphe ends extending onto the valve mantle. In addition, a new combination is suggested for Navicula pseudocrucicula Kobayasi, Prestauroneis pseudocrucicula (Kobayasi) Glushchenko, Kulikovskiy & Kociolek comb. nov. on the basis of type description. P. genkalii sp. nov. is the first member of the genus Prestauroneis reported for Southeast Asia.