<p><strong><em>Gomphonema frequentiformis</em></strong><strong> (Metzeltin &amp; Krammer) <em>comb. nov. </em>(Bacillariophyta): ecology and taxonomy of a Neotropical diatom</strong></p>

Abstract

The transfer of Encyonopsis frequentiformis Metzeltin &amp; Krammer to the genus Gomphonema Ehrenberg is proposed based on observations using light and scanning electron microscopy. The taxon is characterized by lanceolate heteropolar valves, with both apices strongly capitate, two apical pore fields, and elongated areolae slit-like and the internal stigma opens in a slit. Heteropolarity of the specimens measured and other shared similarities with the genus Gomphonema (APF, areolae, external and internal aperture of the isolated pore, pseudosepta at both apices) allows us to classify this species into the genus Gomphonema. Morphological, ecological and distribution data in South America are presented and discussed based on available literature for this Neotropical taxon.

Encyonopsis indonesica sp. nov. (Bacillariophyceae, Cymbellales), a new diatom from the ancient lake Matano (Sulawesi, Indonesia)

“…Despite the rather weak differences, Kurtkrammeria is an accepted genus and several new species have been described since its description (Marquardt et al 2016;Zhang et al 2020). However, sometimes taxa of Gomphonema are misidentified as Encyonopsis or Kurtkrammeria (e.g., Bahls et al 2018;Almeida et al 2020), suggesting a review of the distinguishing features of these genera may be warranted.…”