Stauroneis terryi D.B. Ward ex T.C. Palmer: a forgotten diatom from northeastern North America

Abstract

Stauroneis terryi D.B. Ward ex T.C. Palmer is a diatom so far reported from only five locations in the states of Connecticut, Massachusetts and Maine, USA, where it was collected in 1890—1911. There were no records of this large and rather conspicuous species in any collections made after 1911 despite the considerable number of diatom surveys and paleolimnological studies conducted in the northeastern USA. We studied material from the type locality of this species to document its morphology with SEM, and screened diatom slides representing recent and subfossil samples collected from 169 lakes in northeastern North America from 1979 to 2017 for the presence of this species. Using both whole-slide scanning and traditional microscopy, we detected S. terryi in 15 lakes in the northeastern USA north of 41° N latitude and in five lakes of Labrador and adjacent Quebec, Canada. In the USA, S. terryi populations have declined since pre-industrial times, although the species is still present in a few lakes with relatively undisturbed watersheds. Our observations demonstrate the value of museum collections for generating data on diatom ecology and biogeography and the need for the development of high-throughput methods of extracting information from diatom slides and images.

Keywords:

• biogeography
• endemic
• diatoms
• North America
• Stauroneis
• whole-slide imaging

Acknowledgements

We are grateful to Don Charles for donating Labrador/Quebec slides and associated data files to the ANSP Diatom Herbarium and for maintaining NADED database that was used as a source of archival data for many slides eventually deposited at the Herbarium and used in this study. Environmental data associated with New Jersey samples were provided by Mihaela Enache and Brian Taylor, New Jersey Department of Environmental Protection. We thank Loren Bahls, Sarah Spaulding and Sylvia Lee for productive discussions that contributed to this study.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Supplemental data

Supplemental data for this article can be accessed at https://doi.org/10.1080/0269249X.2022.2078884

Additional information

Funding

This study was supported by the National Science Foundation under Grant number 1938128.