Cocconeis rouxii Héribaud & Brun a forgotten, but common benthic diatom species from the Massif Central, France

ABSTRACT

Cocconeis rouxii was decribed by J.Héribaud & J.Brun from samples collected in mountainous freshwater sources in the Auvergne region, France. Despite being mentioned in earlier publications and classical European floristic books, this species has never been fully explained. Its morphology is poorly known, as it has confusing and sparse citations in the literature, despite being abundant in several samples from the Massif Central. Some inconclusive attempts to investigate the original gatherings during the 1980s, and the exclusion of the taxon in major floristic works, led to the almost complete abandonment of the name. We here detail with light and scanning electron microscopy one population found in the source Bernadette, located near its type locality. The species seems to be quite common in several regions of France with metamorphic geological properties (i.e. crystalline rocks).

KEYWORDS:

• Diatoms
• springs
• mineral waters
• epilithon
• epipelon

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

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

Notes on contributors

Carlos E. Wetzel

Carlos E. Wetzel: botanist and a researcher at the Luxembourg Institute of Science and Technology (LIST) has written over 90 scientific articles related to diatoms. He has been working on diatoms in rivers, lakes and soils, worldwide. Carlos Wetzel has been running numerous training courses on diatom ecology and taxonomy designed for biologists, technicians and ecologists, contributing to the continuous improvement in the Water Framework Directive implementation in Europe.Contribution: conceived the idea, preparation of images, bibliographic research, writing and editing of the manuscript.

Aude Beauger

Aude Beauger: Aude Beauger is an ecologist researcher at the Université Clermont Auvergne. She has written over 20 articles and has been working on diatoms in rivers, lakes and springs. She has been teaching on bioassessment using diatoms.Contribution: collection of samples, performed the chemical analyses and revision of the manuscript.

Luc Ector

Luc Ector: botanist and senior researcher at the Luxembourg Institute of Science and Technology. He has written over 185 articles and has been working on diatoms in rivers, lakes and soils for the last 30 years. He was the President of the “Association des Diatomistes de Langue Française (ADLaF)”, which organizes annual meetings on diatom taxonomy, ecology and related subjects. Over the last 20 years, he has been organizing and teaching numerous training courses on diatom ecology and taxonomy designed for biologists, technicians and ecologists, contributing to the continuous improvement in the Water Framework Directive implementation in Europe.Contribution: discussion of results, bibliographic research, revision and editing of the manuscript.