Nitzschia transtagensis sp. nov. (Bacillariophyceae) from a spring in Southern Portugal

ABSTRACT

A new species of Nitzschia Hassall is described from a small spring in southern Portugal. Nitzschia transtagensis sp. nov. has a unique morphology in the Lineares section, resembling Nitzschia hierosolymitana, N. vitrea and its variety salinarum. The new species is unique in that it has a convex primary (raphe) side with a slightly undulated abvalvar edge of the mantle, and a clearly undulated secondary valve side. This taxon also has a dimorphic open, ligulate cingulum composed of an apically asymmetric valvocopula having one row of roundish pores on the pars interior and attached to the valve secondary side, and two rows of pores (one of roundish and one of elongate pores) attached to the primary side of the valve. All remaining girdle elements have a single row of approximately round pores. The new species is compared to morphologically similar taxa and its ecology is discussed based on available information and literature. Additionally, it was found that a variant of the new species had been reported previously from Sardinia as “Nitzschia aff. ebroicensis”, but the Italian population has coarser stria and puncta densities.

KEYWORDS:

• Bacillariaceae
• diatoms
• Iberian Peninsula
• Europe
• taxonomy

Acknowledgments

We thank Dr. Saúl Blanco for guidance regarding the name of the new species.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

Funding for this research was partly provided the European Union through the European Regional Development Fund, framed in COMPETE 2020 (Operational Programme Competitiveness and Internationalization), through the ICT project (UID/GEO/04683/2013) with reference POCI-01-0145-FEDER-007690, the Alentejo Observation and Prediction Systems - ALOP project (ALT20-03-0145-FEDER-000004), and the Agência Portuguesa do Ambiente, APA-00004DFIN.AALP/2017 integrated within the Operational Program for Sustainability and Efficiency in the Use of Resources 2014-20, POSEUR-03-2013-FC-000001. Co-funding was provided by in the framework of the DIATOMS project (LIST - Luxembourg Institute of Science and Technology).

Notes on contributors

Eduardo A. Morales

Eduardo A. Morales Contribution: Fieldwork, LM analysis, discovery of the new species, paper project designer and promoter, writing and development of the manuscript.

Carlos E. Wetzel

Carlos E. Wetzel Contribution: SEM analysis, plates, discussion of results and development of the manuscript.

Maria Helena Novais

Maria Helena Novais Contribution: fieldwork, sample processing and preparation, data analysis and development of the manuscript.

M. Manuela Morais

M. Manuela Morais Contribution: research project designer, paper promoter and development of the manuscript.

Luc Ector

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