Cocconeis neuquina Frenguelli (Bacillariophyta): emended description, lectotypification, ecology, and geographical distribution

Abstract

In this article, we examine the type material of Cocconeis neuquina Frenguelli from the type locality in Neuquén province and other samples in southern Santa Cruz province (Patagonia, Argentina). Cocconeis neuquina is a small species with an oval-subcircular to broadly elliptical valve outline. The sternum valve is externally convex, striae are radiate and uniseriate, and areolae are rounded towards the mantle. The raphe valve is externally concave, the raphe is straight and filiform, striae are uniseriate, slightly radiate, and the first areola close to the mantle is drop-shaped. With this contribution we aim to clarify the morphology of this species, provide a more detailed description of valve ultrastructure, present its lectotypification and extend its geographical distribution.

Keywords:

• Bacillariophyceae
• Cocconeis
• diatoms
• freshwater
• Patagonia
• South America

Acknowledgements

We would like to thank Lic. Jose Maria Guerrero, curator of the Frenguelli Collection at the Museo de Ciencias Naturales in La Plata for providing the type material of Cocconeis neuquina and helping us with the formalities to designate the lectotype of the species. We also thank E. Reichardt for kindly answering our doubts about C. pseudothumensis and offer special thanks to the anonymous reviewer and the Associated Editor for their valuable suggestions.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This study was funded by Universidad de Buenos Aires [grant numbers 10.13039/501100010253UBACYT 2011–2014 N° 20020100100999 and UBACYT 2014-2017 N° 20020130100413].