Encyonema aquasedis sp. nov. and Kurtkrammeria salesopolensis sp. nov.: two new freshwater diatom species (Cymbellales, Bacillariophyceae) from an oligotrophic reservoir in southeastern Brazil

Abstract

Recent research of the plankton and the surface sediments from Ribeirao do Campo reservoir (Sao Paulo, southeast Brazil) led to identification of two new cymbelloid diatom species: Encyonema acquasedis sp. nov. and Kurtkrammeria salesopolensis sp. nov. Their morphology was studied under both light and scanning electron microscopes aiming at describing the two species in detail. The morphology of each species is compared and discussed with morphologically similar taxa. The new species are different from all others in the Cymbellales due to a combination of characteristics including valve outline, striae, areolae structure, and raphe system. Both species were collected from an oligotrophic environment with both low pH and conductivity.