Two new Punctastriata (Bacillariophyta) species from subalpine French lakes

ABSTRACT

Two new diatom species are described from France. Both species have characters that allow them to be included in the genus Punctastriata D.M.Williams & Round whose main defining character is the “multiseriate striae” (i.e. presence of slender vimines and viminules). Punctastriata subalpina sp. nov. from Lake Annecy has lanceolate valve outline, with slightly heteropolar valves, wide central sternum and Y-bifurcated spines located on the virgae. Some distinguishing features observable in light microscopy (compared to other known small elliptical species in the genus), are the relatively larger cells and the wider distinct sternum. Punctastriata catenata sp. nov. from Lake Entonnoir is similar (under light microscopy) to Staurosirella mutabilis (W.Smith) E.Morales & Van de Vijver and Staurosirella neopinnata E.Morales, C.E.Wetzel, E.Y.Haworth & Ector [= Staurosirella pinnata (Ehrenberg) sensu auct. nonnull]. Punctastriata catenata is characterized by its elongated and elliptic valves, mostly isopolar. The cells have rounded apices and a straight and narrow sternum, and long and strongly silicified spatulated spines rising from the virgae allowing the formation of filaments.

KEYWORDS:

• “Araphid” diatoms
• morphology
• taxonomy
• subalpine lakes
• type material

Disclosure statement

No potential conflict of interest is reported by the authors.

Additional information

Funding

Funding for this research was provided in the framework of the project DIATOMS (LIST – Luxembourg Institute of Science and Technology).

Notes on contributors

Carlos E. Wetzel

Carlos E. Wetzel sample processing, LM and SEM analysis, discussion and writing of the manuscript.

Luc Ector

Luc Ector Provision of literature, discussion of results and critical development of the manuscript.