Craticula widouensis, a new diatom (Bacillariophyta) species of a Sahelian temporary pond (North Senegal)

ABSTRACT

During a floristic survey of temporal ponds in the Sahelian area of North Senegal, a new Craticula species (Bacillariophyceae) was discovered, and it is named here Craticula widouensis Beauger, C.E.Wetzel & Ector sp. nov. The new taxon is formally described using light and scanning electron microscopy. The species presents a unique set of morphological characteristics, including valve dimensions, outline, and presence of conspicuous elongated silica slats at the valve face/valve mantle junction and some narrow apically elongated struts irregularly distributed on the valve face, which make Craticula citrus (Krasske) E. Reichardt the most similar taxon to our knowledge. The ecological preferences of Craticula widouensis sp. nov. are eutrophic, contaminated, and hot ponds. A morphological comparison with the most similar species and a checklist of Craticula taxa are also presented.

KEYWORDS:

• Epipelic diatom
• Sahelian pond
• temporal ecosystem
• Africa
• ultrastructure

Acknowledgments

We thank Saúl Blanco (Department of Biodiversity and Environmental Management, University of León), Michel Coste (Irstea-EABX-ECOVEA, Cestas, France), Jonathan Taylor (School of Biological Sciences, North-West University, South Africa) and Bart Van de Vijver (Botanic Garden Meise, Department of Bryophyta & Thallophyta, Belgium) for their help to find the appropriate bibliography. We also thank Eduardo A. Morales (Laboratório da Água, Universidade de Évora, Portugal) for his precious comments and Diba Khan Bureau (Department of Natural Resources and the Environment, University of Connecticut, USA) for her English corrections. Two anonymous reviewers are thanked for their valuable comments.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was co-financed: i) by the Labex DRIIHM, French program “Investissements d’Avenir” (ANR-11-LABX-0010) which is managed by the Agence Nationale de la Recherche (ANR); ii) by the framework of the DIATOMS project (Luxembourg Institute of Science and Technology).

Notes on contributors

Aude Beauger

Aude Beauger is an ecologist and Ph.D. at the Centre national de la recherche scientifique. She has written over 20 articles and has been working on diatoms in rivers, lakes and springs. Dr. Aude Beauger has been teaching the importance of diatoms as biological indicators of water quality. She is the treasurer of the “Association des Diatomistes de Langue Française (ADLaF).” She has organized the annual meeting on diatom taxonomy, ecology and related subjects in 2014. Contribution: associate of the study in Senegal and developed and wrote this article.

Carlos E. Wetzel

Carlos E. Wetzel is a botanist and a researcher at the Luxembourg Institute of Science and Technology. He has written over 90 articles and he has been researching diatoms in rivers, lakes and soils. Carlos Wetzel has been 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: plates, discussion of results and development of manuscript.

Jean-Luc Peiry

Jean-Luc Peiry is a head of research transferred to the CNRS in Senegal. He works on temporal ponds in the Sahelian area of North Senegal. He has the leadership of one constituents of the Labex DRIIHM, French program “Investissements d’Avenir”. Jean-Luc Peiry has written over 30 articles and has been working on geomorphology of rivers, lakes and soils. Contribution: provided the description of the study site and the discussion of the physical and chemical results; creation of Figure 1.

Olivier Voldoire

Olivier Voldoire is an engineer assistant at the CNRS. He has participated in more than 20 articles. He is specialized in scientific instrumentation and particularly in physical and chemical analyses. Olivier Voldoire participated in the research program. Contribution: provided the physical and chemical analyses, the Table 2 and discussion of the physical and chemical results.

Luc Ector

Luc Ector is a botanist and senior researcher at the Luxembourg Institute of Science and Technology. He has written over 185 articles and has been researching diatoms in rivers, lakes and soils for the last 30 years. Luc Ector 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, development, revision and editing of manuscript.