Nupela (Bacillariophyceae) in littoral rivers from south Brazil, and description of six new species of the genus

The genus Nupela is characterized mainly by structure of the areola and raphe system. Many species were described from tropical regions; however, few studies have been conducted on Brazilian environments. The goal of this article is to identify and describe the morphology of Nupela species, under light and electron microscopy, found in the rivers of the Atlantic Forest from southern Brazil. Twelve species were found, including six described as new: Nupela amabilis TREMARIN et T. LUDWIG, N. difficilis STRAUBE, TREMARIN et T. LUDWIG, N. kocioleckii STRAUBE, TREMARIN et T. LUDWIG, N. metzeltinii TREMARIN et T. LUDWIG, N. praecipuoides TREMARIN et T. LUDWIG and N. torganiae TREMARIN et T. LUDWIG, and a new combination, N. bicapitata (HUSTEDT) TREMARIN et T. LUDWIG.