Morphological studies on type material of widely cited araphid diatoms (Bacillariophyta)

Abstract:

We analysed syntype material of Odontidium harrisonii W. Smith, Odontidium mutabile W. Smith, Odontidium tabellaria W. Smith, Odontidium tabellaria var. β W. Smith, Odontidium parasiticum W. Smith, Odontidium parasiticum var. β W. Smith and Fragilaria brevistriata Grunow in Van Heurck. A combination of light and scanning electron microscopy revealed that taxonomic drift led to currently misconstrued concepts of many of these taxa. Preservation of type materials allowed morphological study of each taxon in detail. The following new combinations, new names and new statuses are presented: Staurosirella harrisonii (W. Smith) E. Morales & C.E. Wetzel comb. nov., Staurosirella mutabilis (W. Smith) E. Morales & Van de Vijver comb. nov. and Pseudostaurosira smithii E. Morales & Ector nom. nov. stat. nov. Nomenclatural and ecological discussions, based on historical and current literature, are presented for each taxon. The study of type materials is a necessary task in order to improve current databases used for taxonomic and ecological purposes, and such a study should be an essential component of large-scale palaeo or neo-limnological research programs.

Key Words::

• Araphid diatoms
• Bacillariophyta
• H. Van Heurck Collection
• Pseudostaurosira
• Staurosira
• Staurosirella
• Type material
• W. Smith

ACKNOWLEDGEMENTS

This research was supported the Public Research Centre-Gabriel Lippmann, Belvaux, Luxembourg (now Luxembourg Institute of Science and Technology) within the framework of the projects FLORALIE and TAXODIA. We gratefully acknowledge Myriam de Haan (Botanic Garden Meise), Maria Helena Novais and Delphine Collard (Luxembourg Institute of Science and Technology, Environmental Research and Innovation Department) for technical assistance in preparation of the samples for LM and SEM investigations. The main results of this study have been presented during the Second European Workshop on Diatom Taxonomy (Araphid freshwater diatoms) held in September 2013 at Thonon-les-Bains (France). This manuscript has been greatly improved by the critical reviews, corrections and suggestions of Saúl Blanco (University of León, Spain), Paul B. Hamilton (Canadian Museum of Nature, Ottawa), David M. Williams (British Museum, London) and David J. Garbary (St. Francis Xavier University, Antigonish, Nova Scotia, Canada). Our present work is dedicated to the career of Friedel Hinz and her untiring labour at the Friedrich Hustedt Diatom Study Centre (Bremerhaven, Germany). Her dedication and promptness always resulted in good quality data collected by colleagues around the world, who analysed the material and references she graciously and expeditiously provided through the years.