A new Encyonema species from the Brazilian Pampa Biome

Abstract

This paper describes Encyonema macieliarum sp. nov., collected from epilithic substrates in lotic environments of the Ibicuí river catchment (southern Brazil, Pampa Biome). The material was examined with the LM and SEM. Morphological analysis and PCA helped to separate the new species from the most similar taxon: Encyonema sprechmannii. The new species E. macieliarum can be differentiated from the others within the genus by a set of characteristics, which includes its valve outline, stria pattern, and absence of intermission. The species is found in oligotrophic to mesotrophic environments, in streams with more stable flow. This finding contributes to the morphological understanding of Encyonema and emphasizes the taxonomic relevance of the underexplored Pampa Biome.