MORPHOLOGICAL STUDIES ON SELECTED TAXA IN THE GENUS STAUROSIRELLA WILLIAMS ET ROUND (BACILLARIOPHYCEAE) FROM RIVERS IN NORTH AMERICA

Abstract

Morphological studies at the light microscopy (LM) and scanning electron microscopy (SEM) levels of selected fragilarioid diatoms within the genus Staurosirella Williams et Round occurring in North American streams and rivers are presented herein. The studied samples were collected by the U.S. Geological Survey's National Water Quality Assessment Program (NAWQA), which concentrates on stream water quality monitoring throughout the continental United States and Hawaii. Two new species (Staurosirella ovata Morales and Staurosirella subrobusta Morales), one new combination (Staurosirella martyi (Héribaud) Morales), and three new combinations/new status (Staurosirella dubia (Grunow) Morales, S. rhomboides (Grunow) Morales, and S. subcapitata (Frenguelli) Morales) are presented. Additionally, detailed morphological information of one additional taxon (Staurosirella leptostauron (Ehrenberg) Williams et Round,) is provided. The taxonomie affinities of all these taxa, as well as some ecological aspects are discussed in the light of published and newly collected material.