Chamaepinnularia mirim sp. nov., a new rare diatom (Bacillariophyta) from coastal lakes of southern Brazil

Chamaepinnularia is a small and diverse genus comprises of almost 70 species, whose origin remains uncertain, including taxa previously classified as Navicula and others Pinnularia. A new Chamaepinnularia species (Bacillariophyeceae) was found for Neotropical region, which still harbors significant taxonomic gaps for the genus. Named Chamaepinnularia mirim sp. nov it is distinguished from other Chamaepinnularia species by its wider central inflation along the median portion of the valve, extending towards the apices, and by a more radiant striation pattern.This new species occurs in epiphytic habitats in subtropical coastal lakes of Brazil.

Morphological details were documented using both light and scanning electron microscopy, and insights into its differences from closely related species are discussed.