Staurosirella andino-patagonica sp. nov. (Bacillariophyta) from lake sediments in Patagonia, Argentina

Abstract

Staurosirella andino-patagonica, a new araphid diatom found in Holocene and recent surface sediments from lakes located in the Andes and adjacent steppe of Patagonia (Argentina), is described on the basis of light and scanning electron microscopy observations and comparison with related taxa. Although the elliptic valve outline of the new taxon resembles the smaller specimens of several Staurosirella species, ultrastructural features such as the presence of two spines on each virga and their distinct morphology-serrated with thickenings at the base-make Staurosirella andino-patagonica unique within the genus. Our study contributes to the knowledge of the Patagonian araphid diatom flora, a rather unexplored geographic area, and so we assume that, as additional areas are studied in detail, they will likely continue to yield new taxa.