Morphology and distribution of Encyonema angustecapitatum Krammer species complex (Bacillariophyceae) with description of four new species from São Paulo, southeast Brazil

Abstract

Type material of Encyonema angustecapitatum KraMMer was investigated to establish the identity of several Brazilian Encyonema populations. In order to elucidate the differences and similarities of that species complex, morphological features under light and scanning electron microscopy were detailed. Notes on their distribution were also discussed. MDS analysis distinguished four Encyonema species presently described as new to science: Encyonema acquapurae sp. nov., Encyonema sparsistriatum sp. nov., Encyonema tenue sp. nov. and Encyonema paradisiacum sp. nov. The four new species can be separated on the basis of a combination of the following morphological features: valve outline, axial area, valve length, valve width, length to width ratio, number of striae in 10 μm and number of areolae in 10 μm. Regarding ecological preferences, all four species were mainly found in oligotrophic and oligo-mesotrophic environments.

Periphytic diatoms from an oligotrophic lentic system, Piraquara I reservoir, Paraná state, Brazil

“…Recent studies in oligotrophic Brazilian reservoirs contributed to the description of new diatom species in the genera Kurtkrammeria and Encyonema (Marquardt et al 2016, Marquardt et al 2017 and extended the geographic distribution of the already known species (Canani et al 2011). Paleolimnological studies with diatoms are important in providing a further understanding of biodiversity, detecting the response of the assemblages over time.…”

Contribution to the inventory of Iberian diatoms: <em>Encyonema nevadense</em> S.Blanco & al. sp. nov. (<em>Cymbellales, Gomphonemataceae</em>)

“…La especie aquí descrita puede ser confundida con otras especies del género Encyonema, singularmente los táxones descritos en Marquardt & al. (2017) dentro del complejo de especies entorno a E. angustecapitatum Krammer.…”