Plant Ecology and Evolution 152(2): 368-377, doi: 10.5091/plecevo.2019.1594
The novel species Navicula eileeniae (Bacillariophyta, Naviculaceae) and its recent expansion in the Central Appalachian region of North America
expand article infoMarina G. Potapova‡, Ionel Ciugulea§, Alison Minerovic‡
‡ The Academy of Natural Sciences, Drexel University, Philadelphia, PA, United States of America§ atrick Center for Environmental Research, Academy of Natural Sciences of Drexel University, Philadelphia, PA 19103, United States of America

Corresponding author: Marina Potapova ( marina.potapova@drexel.edu )

© Marina G. Potapova, Ionel Ciugulea, Alison Minerovic.
This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Citation: Potapova MG, Ciugulea I, Minerovic A (2019) The novel species Navicula eileeniae (Bacillariophyta, Naviculaceae) and its recent expansion in the Central Appalachian region of North America. Plant Ecology and Evolution 152(2): 368-377. https://doi.org/10.5091/plecevo.2019.1594
Open Access
Abstract

Background and aims – A novel species of Navicula has been recently discovered in rivers of the central Appalachian Mountains, USA. The purpose of this paper is to formally establish this new species and to determine whether it had been overlooked in the past or is a recent arrival to the area.

Methods – We studied historical collections made in Pennsylvania, Virginia and adjacent areas since the 1940s and housed at the ANSP Diatom Herbarium. Light and scanning electron microscopy was employed to study the morphology of the new species and similar Navicula taxa, including those commonly reported at the same locations, or originally described from the rivers of the eastern United States, such as N. radiosafallax, initially established as N. radiosa var. parva by J.H. Wallace.

Key results – The new species has an unusual shape of the external raphe slit, which is undulate toward the proximal ends. This character was so far found in a single other Navicula species known only from Europe. Examination of historical materials confirmed that N. eileeniae was absent from collections made in the eastern United States before 2007, but has become progressively more common and abundant in the last decade. The prevalence of this species in streams of low to moderate mineral and nutrient content suggests that its recent expansion cannot be explained by pollution. Climate change is also unlikely to have caused the northward expansion of N. eileeniae, as it has never been recorded south from central Appalachia.

Conclusions – The results of this study confirm that a population of previously unknown Navicula species has been expanding in Central Appalachia and suggest that rapid shifts of distributional ranges not readily explainable by environmental changes may occur in protists.

Keywords
Bacillariophyta, diatoms, morphology, new species, Navicula, rivers, taxonomy, United States

References

  • Bahls L. (2012a) Navicula lundii. In: Diatoms of North America. Available from https://diatoms.org/species/navicula_lundii [accessed 4 Oct. 2018].
  • Bahls L. (2012b) Navicula wildii. In: Diatoms of North America. Available from https://diatoms.org/species/navicula_wildii [accessed 4 Oct. 2018].
  • Charles D.F., Knowles C., Davis R.S. (2002) Protocols for the analysis of algal samples collected as part of the U.S. Geological Survey National Water-Quality Assessment Program. Report No. 02-06. Philadelphia , PA, The Academy of Natural Sciences. Available from http://diatom.ansp.org/nawqa/pdfs/ProtocolPublication.pdf [accessed 1 Mar. 2019].
  • Cox E.J. (1979) Taxonomic studies on the diatom genus Navicula Bory: the typification of the genus. Bacillaria 2: 137–153.
  • Cox E.J. (1981) The use of chloroplasts and other features of the living cell in the taxonomy of naviculoid diatoms. In: Ross R. (ed.) Proceedings of the 6th Diatom Symposium, Budapest, 1980: 115–133. Koenigstein, Koeltz.
  • Cox E.J. (1982) Taxonomic studies on the diatom genus Navicula Bory. IV. Climaconeis Grun., a genus including Okedenia inflexa (Bréb.) Eul. and some members of Navicula sect. Johnsoniae sensu Hustedt. British Phycological Journal 17: 147–168. https://doi.org/10.1080/00071618200650161
  • Cox E.J. (1995) Taxonomic studies on the diatom genus Navicula Bory. VII. The identity and typification of Navicula gregaria Donkin, N. cryptocephala Kütz. and related taxa. Diatom Research 10: 91–111. https://doi.org/10.1080/0269249X.1995.9705330
  • Cox E.J. (1999a) Studies on the diatom genus Navicula Bory. VIII. Variation in valve morphology in relation to the generic diagnosis based on Navicula tripunctata (O.F. Muller) Bory. Diatom Research 14: 207–237. https://doi.org/10.1080/0269249X.1999.9705467
  • Cox E.J. (2010) Morphogenetic information and the selection of taxonomic characters for raphid diatom systematics. Plant Ecology and Evolution 143: 271–277. https://doi.org/10.5091/plecevo.2010.403
  • Cox E.J. (2012) Ontogeny, homology, and terminology – wall morphogenesis as an aid to character recognition and character state definition for pennate diatom systematics. Journal of Phycology 48: 1–31. https://doi.org/10.1111/j.1529-8817.2011.01081.x
  • Cox E.J., Reid G. (2004) Generic relationships within the Naviculineae a preliminary analysis. In: Poulin M. (ed.) Proceedings of the 17th International Diatom Symposium, Ottawa, Canada: 49–62. Bristol, Biopress.
  • Cox E.J., Williams D.M. (2006) Systematics of naviculoid diatoms (Bacillariophyta): a preliminary analysis of protoplast and frustule characters for family and order level classification. Systematics and Biodiversity 4: 385–399. https://doi.org/10.1017/S1477200006001940
  • Dobosz S., Lange-Bertalot H., Bąk M, Witkowski A., Hofmann G. (2017) Navicula paracari sp. nov. – a new and neglected diatom species abundant in calcareous lakes of Central Europe. Nova Hedwigia, Beiheft 146: 137–146. https://doi.org/10.1127/1438-9134/2017/137
  • Harper M.A. (1977) Movements. In: Werner D. (ed.) The biology of diatoms: 224–249. Oxford, Blackwell.
  • Kermarrec L., Franc A., Rimet F., Chaumeil P., Humbert J.F., Bouchez A. (2013) Next-generation sequencing to inventory taxonomic diversity in eukaryotic communities: a test for freshwater diatoms. Molecular Ecology Resources 13: 607–619. https://doi.org/10.1111/1755-0998.12105
  • Kloster M., Esper O., Kauer G., Beszteri B. (2017) Large-scale permanent slide imaging and image analysis for diatom morphometrics. Applied Sciences 7(4): 330. https://doi.org/10.3390/app7040330
  • Lange-Bertalot H. (1993) 85 Neue taxa und über 100 weitere neu definierte Taxa ergänzend zur Süßwasserflora von Mittleuropa. Bibliotheca Diatomologica 27:1–454.
  • Lange-Bertalot H. (2001) Navicula sensu stricto, 10 genera separated from Navicula sensu lato, Frustulia. Diatoms of Europe 2: 1–526.
  • Patrick R.M., Reimer C.W. (1966) The Diatoms of the United States exclusive of Alaska and Hawaii, V. 1 Monographs of the Academy of Natural Sciences of Philadelphia 13: 1–688.
  • Pérès F., Barthès A., Ponton E., Coste M., Ten-Hague L., Le Cohu R. (2012) Achnanthidium delmontii sp. nov., a new species from French rivers. Fottea 12: 189–198. https://doi.org/10.5507/fot.2012.014
  • Potapova M. (2009) Navicula recens. In: Diatoms of North America. Available from https://diatoms.org/species/navicula_recens [accessed 4 Oct. 2018].
  • Potapova M. (2011) Navicula reichardtiana. In: Diatoms of North America. Available from https://diatoms.org/species/navicula_reichardtiana [accessed 4 Oct. 2018].
  • Round F.E., Crawford R.M., Mann D.G. (1990) The diatoms. Biology and morphology of the genera. Cambridge, Cambridge University Press.
  • Spaulding S.A., Kilroy C., Edlund M. (2010) Diatoms as invasive species In: Smol J., Stoermer E.F. (eds) The Diatoms: Applications for the Environmental and Earth Sciences: 560–569. Cambridge, Cambridge University Press.
  • Van de Vijver B., Jarlman A., Lange-Bertalot H. (2010) Four new Navicula (Bacillariophyta) species from Swedish rivers. Cryptogamie, Algologie 31: 355–367.
  • Wallace J. (1960) New and variable diatoms. Notulae Naturae 331: 1–8.