Eunotogramma litorale sp. nov., a marine epipsammic diatom from Southern California, USA

Abstract

Eunotogramma litorale sp. nov. is described from marine littoral epipsammic assemblages collected from San Diego County, Southern California, USA. The valves of this common species are semi-elliptical in outline with a curved dorsal margin and a more or less straight ventral margin. Each valve has 1–6 transapical costae. Areolae are absent on the valve face; a small rimoportula is usually present on the valve face or uppermost mantle near each pole. One or more rimoportulae are usually found in a row along the dorsal mantle between the costae. Small areolae, visible only with SEM, are typically found between costae on the ventral mantle and along the ventral portion of the pars exterior of the valvocopulae. E. litorale can be distinguished from three other Eunotogramma species with hyaline valve faces by the semi-elliptical shape of its valve outline. The similarity of the internal openings of the rimoportuale of E. litorale and some Aulacodiscus species suggests that E. litorale may be allied with Aulacodiscus, a marine genus associated with inshore beaches.

Keywords:

• Eunotogramma
• new species
• epipsammic
• marine
• taxonomy
• diatoms

Acknowledgements

I am very much indebted to Dr Mike Sullivan for his insightful comments and encouragement on early iterations of this manuscript. I thank Dr Richard Crawford and Friedel Hinz of the Alfred-Wegener-Institut für Polar- und Meeresforschung for providing unmounted material used by Hustedt for his 1955 Beaufort paper, and Dr Robert Edgar and Genevieve Lewis-Gentry of the Farlow Herbarium and Dr Marina Potapova of the Academy of Natural Sciences of Philadelphia for the loan of the priceless Cleve & Möller slides. I also thank Lou Ross, Randy Tindall, and Cheryl Jensen of the University of Missouri, Columbia’s Electron Microscopy Core Facility for their expertise with the scanning electron microscope, Dr April Collins Potterfield for collecting mud samples from Beaufort, Dr Robert Seelinger for his command of the classical Greek and Latin languages, Dr Bernie Hansert for the translation of critical German passages, and especially Ryan Counts for preparation of the plates. And many thanks to two anonymous reviewers and Dr Rosa Trobajo for their thorough and valuable feedback.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This study was supported by funds from the Cameron D. Day Endowed Chair of Biology and a Faculty Summer Research Stipend from Westminster College.