Sellaphora tropicomadida sp. nov., a new freshwater diatom species (Bacillariophyta) from a tropical Brazilian reservoir
Authors
G.C. Marquardt, C.E.M. Bicudo, L. Ector, and C.E. Wetzel
Reference
Brazilian Journal of Botany, vol. 40, no. 4, pp. 1051–1062, 2017
Description
A new periphytic freshwater diatom species belonging to the genus Sellaphora Mereschkowsky has been recorded from a reservoir in São Paulo (Southeast Brazil) and is described as S. tropicomadida Marquardt and C.E. Wetzel, sp. nov. The new species most distinctive feature is the areolae internal ultrastructure, composed of large occlusions laid very close to the raphe, restricting an almost absent central area. Sellaphora madida (Kociolek) C.E. Wetzel in Wetzel et al. originally described from the USA. (Oregon) has been recently collected from locations different from the type locality and presents a disjunct distribution, with confirmed records in subtropical regions of South America (southern Brazil) and Europe (Bulgaria). These specimens were compared with those of S. tropicomadida sp. nov. to highlight the differences between them. All populations are illustrated in detail with light microscope (LM) and scanning electron microscope (SEM). Further comparisons of S. tropicomadida with similar species based on the literature and information about their ecology are also provided. We suggest careful examination of the small size dominant diatoms with SEM in routine monitoring, to get better results and increase taxonomic accuracy for ecological assessment, mainly concerning species with distinct ecological preferences, despite their morphological resemblance.
