Melosira jeanbertrandiana, a new Melosira species (Bacillariophyceae) from the sub-Antarctic region

ABSTRACT

During a survey of the soil diatom flora of the sub-Antarctic Ile de la Possession (Iles Crozet), located in the southern Indian Ocean, an unknown Melosira species was found that could not be identified using the currently available literature on the genus. The species is described as Melosira jeanbertrandiana sp. nov. based on detailed light and scanning electron microscopy observations. The new species is characterized by a relatively high mantle, the presence of several marginal rings of acute, never bifurcating spines and a series of eight rimoportulae near the central area with several others scattered over the rest of the valve face and mantle. The girdle comprising several large, ligulate open copulae and the position of the rimoportulae clearly place this new species within the genus Melosira C.Agardh. The species was observed in bare, moist soil in scratches in cliffs bordering the ocean where the influence of sea spray is obvious. The description of this new species further increases the number of species of the Melosirales compared to other centric freshwater diatoms which are infrequently found on the sub-Antarctic islands.

KEYWORDS:

• Sub-Antarctica
• melosiroid genera
• morphology
• new species
• Melosira

Acknowledgments

Sampling on Iles Crozet and Iles Kerguelen was made possible with the logistic support of the Institut Polaire Français - Paul-Emile Victor (IPEV) in the frame of the Terrestrial Ecology program 136 (Dr. Yves Frenot & Ir. Marc Lebouvier). Dr. Alex Ball and the staff of the IAC laboratory at the Natural History Museum are thanked for their help with the scanning electron microscopy.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This study was supported by the BELSPO MICROBIAN project to visit the National History Museum in London, UK.

Notes on contributors

Bart Van de Vijver

Bart Van de Vijver is a full-time researcher at the Meise Botanic Garden, Belgium, and a part-time professor at the University of Antwerp, Belgium. His research focuses mainly on the taxonomy, morphology and biogeography of Antarctic freshwater and terrestrial diatoms. He has been studying non-marine diatoms in various parts of the Antarctic region for more than 20 years. He has described almost 400 new taxa and revised an additional 250 taxa. Contribution: identification of diatom species, discussion of results and writing and editing of the manuscript.

Richard M. Crawford

Richard M. Crawford retired in 2010 from the post of Curator of the Friedrich Hustedt Collection in Bremerhaven, Germany after a career researching the morphology and taxonomy of several genera, freshwater and marine, that had been grouped together in Melosira. These now exist as individual genera, e.g. Ellerbeckia Crawford, Aulacoseira Thwaites and Melosira s.s. Contribution: identification of diatom species, taxonomic discussions.