<i>Aulacoseira kruegeriana</i> (Diatomeae, Coscinodiscophyceae): a new centric diatom from high-elevation Andean rivers and streams of Bolivia

Abstract

A new centric diatom, Aulacoseira kruegeriana sp. nov., collected from small streams in the Yungas (cloud forest) region of Bolivia, is described based on light and electron microscopy. The new species is morphologically similar to Aulacoseira principissa Van de Vijver, A. alpigena (Grunow) Krammer, A. ambigua (Grunow) Simonsen, A. gessneri (Hustedt) Simonsen, A. laevissima (Grunow in Van Heurck) Krammer, A. lirata (Ehrenberg) Ross, and A. nygaardii (Camburn) Camburn & D.F. Charles. However, it is distinguished by its finer frustule structure, presence and features of separation and linking spines, density of areolae, rotae as mostly three-point bars, a solid and thick ringleist and indistinctly sigmoid mantle striae. Aulacoseira kruegeriana is the first new species of Aulacoseira. Thwaites reported from Bolivia. However, the literature on centric diatoms in this country is currently scarce and, as more research is conducted on streams and lakes, it is likely that additional novel centric diatoms will be discovered.