Homothallism, morphology and phylogenetic position of a new species of Sellaphora (Bacillariophyta), S. pausariae
Cover of volume 152, number 2 of Plant Ecology and Evolution

Supplementary Files

Supplementary File 1
Supplementary File 2
Supplementary File 3
Supplementary File 4
Supplementary File 5
Supplementary File 6
Supplementary File 7


mating data
molecular systematics
new species

How to Cite

Mann, D. and Poulíčková, A. (2019) “Homothallism, morphology and phylogenetic position of a new species of Sellaphora (Bacillariophyta), S. pausariae”, Plant Ecology and Evolution, 152(2), pp. 203-218. doi: 10.5091/plecevo.2019.1626.


Background and aims – The eutrophic Blackford Pond in Edinburgh has already provided the holotypes of six other Sellaphora species. A further undescribed species is present and requires description and characterization.

Methods – Clones of the new species are characterized by light (LM) and scanning electron microscopy (SEM) and molecular phylogenetics (from a concatenated five-gene alignment of 18S rDNA, 28S rDNA, 23S rDNA, cox1 and rbcL, and a two-gene alignment of cox1 and rbcL).

Key resultsSellaphora pausariae sp. nov. is named in honour of Dr Eileen Cox (‘pausaria’ = a lady coxswain). In molecular phylogenies, small-celled Sellaphora species (‘minima’ and ‘seminulum’ morphologies) branch off at the base of Sellaphora, though nodes are not well supported. Species and demes previously classified in either “Navicula pupula” or “Navicula bacillum” group into three very well supported clades (numbered 1–3). Although appearing in LM and SEM like a smaller, more delicate version of S. obesa, S. pausariae (clade 1) is not closely related to S. obesa (clade 2). Features of Sellaphora pausariae not confirmed previously in any Sellaphora but possibly widespread are: (a) hymenes with pores arranged in a regular scatter; (b) a stepped mantle near the poles; and (c) a ‘primodominant’ girdle comprising a wide band 1, a segmental band 2, and two extremely thin bands at the abvalvar end of the girdle. Sellaphora pausariae is homothallic; a deficiency of interclonal pairings in two-clone mixtures is interpreted as reflecting the tendency of cells to mate with their immediate neighbours.

Conclusions – Morphologically, the new species can be differentiated from existing described species, though only problematically from some informally named demes. Molecularly, it is clearly characterized by the five genes sequenced. Girdle terminology needs expansion (e.g. to distinguish primodominant girdles from ‘graded’ ones, in which the bands gradually decrease in width and structural complexity from the valve outwards).



Ács É., Wetzel C.E., Buczkó K., Kiss K.T., Nagy K., Trábert Z., Földi A., Pozderka V., Werner P., Heudre D., Ector L. (2017) Biogeography and morphology of a poorly known Sellaphora species. Fottea 17: 57–64. https://doi.org/10.5507/fot.2016.021

De Decker S., Vanormelingen P., Pinseel E., Sefbom J., Audoor S., Sabbe K., Vyverman W. (2018) Incomplete reproductive isolation between genetically distinct sympatric clades of the pennate model diatom Seminavis robusta. Protist 169: 569–583. https://doi.org/10.1016/j.protis.2018.05.003

Droop S.J.M., Mann D.G., Lokhorst G.M. (2000) Spatial and temporal stability of demes in Diploneis smithii/D. fusca (Bacillariophyta) supports a narrow species concept. Phycologia 39: 527–546. https://doi.org/10.2216/i0031-8884-39-6-527.1

Edgar R.C. (2004) MUSCLE: multiple sequence alignment with high accuracy and high throughput. Nucleic Acids Research 32: 1792–1797. https://doi.org/10.1093/nar/gkh340

Evans K.M., Mann D.G. (2009) A proposed protocol for nomenclaturally effective DNA barcoding of microalgae. Phycologia 48: 70–74. https://doi.org/10.2216/08-70.1

Evans K.M., Wortley A.H., Mann D.G. (2007) An assessment of potential diatom “barcode” genes (cox1, rbcL, 18S and ITS rDNA) and their effectiveness in determining relationships in Sellaphora (Bacillariophyta). Protist 158: 349–364. https://doi.org/10.1016/j.protis.2007.04.001

Evans K.M., Wortley A.H., Simpson G.E., Chepurnov V.A., Mann D.G. (2008) A molecular systematic approach to explore diversity within the Sellaphora pupula species complex (Bacillariophyta). Journal of Phycology 44: 215–231. https://doi.org/10.1111/j.1529-8817.2007.00454.x

Falasco E., Blanco S., Bona F., Gomà J., Hlúbiková D., Novais M.H., Hoffmann L., Ector L. (2009) Taxonomy, morphology and distribution of the Sellaphora stroemii complex (Bacillariophyceae). Fottea 9: 243–256. https://doi.org/10.5507/fot.2009.025

Friedrichs L., Maier M., Hamm C. (2012) A new method for exact three-dimensional reconstructions of diatom frustules. Journal of Microscopy 248: 208–217. https://doi.org/10.1111/j.1365-2818.2012.03664.x

Guillard R.R.L., Lorenzen C.L. (1972) Yellow-green algae with chlorophyllide c. Journal of Phycology 8: 10–14. https://doi.org/10.1111/j.1529-8817.1972.tb03995.x

Guiry M.D., Guiry G.M. (2018) AlgaeBase. World-wide electronic publication, National University of Ireland, Galway. Available from http://www.algaebase.org [accessed 1 Aug. 2018].

Hamsher S.E., Evans K.M., Mann D.G., Poulíčková A., Saunders G.W. (2011) Barcoding diatoms: exploring alternatives to COI-5P. Protist 162: 405–422. https://doi.org/10.1016/j.protis.2010.09.005

Hustedt F. (1930) Bacillariophyta. In: Pascher A. (ed.) Die Süsswasser-Flora Mitteleuropas, vol. 10 (ed. 2). Jena, G. Fischer.

Hustedt F. (1961) Die Kieselalgen Deutschlands, Österreichs und der Schweiz unter Berücksichtigung der übrigen Länder Europas sowie der angrenzenden Meeresgebiete. In: Dr L. Rabenhorst’s Kryptogamenflora von Deutschland, Österreich und der Schweiz, vol. 7(3:1): 1–160. Leipzig, Akademische Verlagsgesellschaft.

Idei M. (2013) Three new species of freshwater Diploneis from Japan. Diatom Research 28: 1–11. https://doi.org/10.1080/0269249X.2012.734527

Kelly M., Boonham N., Juggins S., Kille P., Mann D., Pass D., Sapp M., Sato S., Glover R. (2018) A DNA based diatom metabarcoding approach for Water Framework Directive classification of rivers. SC140024/R. Bristol, Environment Agency.

Krammer K., Lange-Bertalot H. (1986) Bacillariophyceae 1. Teil: Naviculaceae. In: Ettl H., Gerloff J., Heynig H., Mollenhauer D. (eds) Süsswasserflora von Mitteleuropa, 2/1: 1–876. Stuttgart & New York, G. Fischer.

Kumar S., Stecher G., Tamura K. (2016) MEGA7: Molecular Evolutionary Genetics Analysis version 7.0 for bigger datasets. Molecular biology and evolution 33: 1870–1874. https://doi.org/10.1093/molbev/msw054

Letunic I., Bork P. (2016) Interactive tree of life (iTOL) v3: an online tool for the display and annotation of phylogenetic and other trees. Nucleic Acids Research 44(W1): W242–W245. https://doi.org/10.1093/nar/gkw290

Liu B., Williams D.M., Ou Y. (2017) Adlafia sinensis sp. nov. (Bacillariophyceae) from the Wuling Mountain Area, China, with reference to the structure of its girdle bands. Phytotaxa 298: 43–54. https://doi.org/10.11646/phytotaxa.298.1.4

Liu B., Williams D.M., Liu Q. (2018) A new species of Cymbella (Cymbellaceae, Bacillariophyceae) possessing valve with both uniseriate and biseriate striae. Phytotaxa 344: 39–46. https://doi.org/10.11646/phytotaxa.344.1.5

Lu J., Sun C., Wang J. (2015) Mechanical simulation of a diatom frustule structure. Journal of Bionic Engineering 12: 98–108.

Mann D.G. (1981) Sieves and flaps: siliceous minutiae in the pores of raphid diatoms. In: Ross R. (ed.) Proceedings of the 6th Symposium on Recent and Fossil Diatoms: 279–300. Koenigstein, O. Koeltz.

Mann D.G. (1984) Observations on copulation in Navicula pupula and Amphora ovalis in relation to the nature of diatom species. Annals of Botany 54: 429–438. https://doi.org/10.1093/oxfordjournals.aob.a086813

Mann D.G. (1989a) The diatom genus Sellaphora: separation from Navicula. British Phycological Journal 24: 1–20. https://doi.org/10.1080/00071618900650011

Mann D.G. (1989b) The species concept in diatoms: evidence for morphologically distinct, sympatric gamodemes in four epipelic species. Plant Systematics and Evolution 164: 215–237.

Mann D.G. (2008) The genus Sellaphora: an addition and corrections. Fottea 8: 117–119.

Mann D.G., Vanormelingen P. (2013) An inordinate fondness? The number, distributions and origins of diatom species. Journal of Eukaryotic Microbiology 60: 414–420. https://doi.org/10.1111/jeu.12047

Mann D.G., Chepurnov V.A., Droop S.J.M. (1999) Sexuality, incompatibility, size variation, and preferential polyandry in natural populations and clones of Sellaphora pupula (Bacillariophyceae). Journal of Phycology 35: 152–170. https://doi.org/10.1046/j.1529-8817.1999.3510152.x

Mann D.G., McDonald S.M., Bayer M.M., Droop S.J.M., Chepurnov V.A., Loke R.E., Ciobanu A., Du Buf J.M.H. (2004) Morphometric analysis, ultrastructure and mating data provide evidence for five new species of Sellaphora (Bacillariophyceae). Phycologia 43: 459–482.

Mann D.G., Thomas S.J., Evans K.M. (2008) Revision of the diatom genus Sellaphora: a first account of the larger species in the British Isles. Fottea 8: 15–78.

Mann D.G., Evans K.M., Chepurnov V.A., Nagai S. (2009) Morphology and formal description of Sellaphora bisexualis, sp. nov. (Bacillariophyta). Fottea 9: 199–209. https://doi.org/10.5507/fot.2009.021

Mann D.G., Poulíčková A., Sato S., Evans K.M. (2011) Scaly incunabula, auxospore development, and girdle polymorphism in Sellaphora marvanii sp. nov. (Bacillariophyceae). Journal of Phycology 47: 1368–1378. https://doi.org/10.1111/j.1529-8817.2011.01058.x

Mereschkowsky C. (1902) On Sellaphora, a new genus of diatoms. Annals and Magazine of Natural History, series 7, 9: 185–195.

Metzeltin D., Lange-Bertalot H. (2002) Diatoms from the “Island Continent” Madagascar. Iconographia diatomologica 11: 1–286.

Metzeltin D., Lange-Bertalot H., Soninkhishig N. (2009) Diatoms in Mongolia. Iconographia diatomologica 20: 3–686.

Müller O. (1910) Bacillariaceen aus dem Nyassalande und einigen benachbarten Gebieten. IV. Engler’s Botanische Jahrbücher 45: 69–122.

Ognjanova-Rumenova N. (2005) Upper Neogene siliceous microfossils from Pelagonia Basin (Balkan Peninsula). Geologica carpathica 56: 347–58.

Potapova M., Charles D.F. (2004) Potential use of rare diatoms as environmental indicators in U.S.A. rivers. In: Poulin M. (ed.) Proceedings of the 17th International Diatom Symposium: 281–295. Bristol, Biopress Limited.

Potapova M., Ponader K. (2008) New species and combinations in the diatom genus Sellaphora (Sellaphoraceae) from the Southeastern United States. Harvard Papers in Botany 13: 171–181.

Poulíčková A., Špačková J., Kelly M.G., Duchoslav M., Mann D.G. (2008) Ecological variation within Sellaphora species complexes (Bacillariophyceae) – specialists or generalists? Hydrobiologia 614: 373–386. https://doi.org/10.1007/s10750-008-9521-y

Poulíčková A., Sato S., Evans K.M., Chepurnov V.A., Mann D.G. (2015) Repeated evolution of uniparental reproduction in Sellaphora (Bacillariophyceae). European Journal of Phycology 50: 62–79. https://doi.org/10.1080/09670262.2014.985259

Poulíčková A., Kollár J., Hašler P., Dvořák P., Mann D.G. (2019) A new species Pinnularia lacustrigibba sp. nov. within the Pinnularia subgibba group (Bacillariophyceae). Diatom Research 33: 273–282. https://doi.org/10.1080/0269249X.2018.1513869

Round F.E., Crawford R.M., Mann D.G. (1990) The diatoms. Biology and morphology of the genera. Cambridge, Cambridge University Press.

Silvestro D., Michalak I. (2012) raxmlGUI:a graphical front-end for RAxML. Organisms Diversity and Evolution 12: 335–337. https://doi.org/10.1007/s13127-011-0056-0

Stamatakis A. (2014) RAxML version 8: a tool for phylogenetic analysis and post-analysis of large phylogenies. Bioinformatics 30: 1312–1313. https://doi.org/10.1093/bioinformatics/btu033

Stosch H.A. von (1975) An amended terminology of the diatom girdle. Nova Hedwigia, Beiheft 53: 1–28.

Trobajo R., Mann D.G., Chepurnov V.A., Clavero E., Cox E.J. (2006) Taxonomy, life cycle, and auxosporulation of Nitzschia fonticola (Bacillariophyta). Journal of Phycology 42: 1353–1372. https://doi.org/10.1111/j.1529-8817.2006.00291.x

Trobajo R., Rovira L., Ector L., Wetzel C.E., Kelly M., Mann D.G. (2013) Morphology and identity of some ecologically important small Nitzschia species. Diatom Research 28: 37–59.

Vanormelingen P., Evans K.M., Chepurnov V.A., Vyverman W., Mann D.G. (2013) Molecular species discovery in the diatom Sellaphora and its congruence with mating trials. Fottea 13: 133–148. https://doi.org/10.5507/fot.2013.012

Vasselon V., Rimet F., Tapolczai K., Bouchez A. (2017) Assessing ecological status with diatoms DNA metabarcoding: Scaling-up on a WFD monitoring network (Mayotte island, France). Ecological Indicators 82: 1–12. https://doi.org/10.1016/j.ecolind.2017.06.024

Wetzel C.E., Ector L., Van de Vijver B., Compère P., Mann D.G. (2015) Morphology, typification and critical analysis of some ecologically important small naviculoid species (Bacillariophyta). Fottea 15: 203–234. https://doi.org/10.5507/fot.2015.020

Witkowski A., Barka F., Mann D.G., Li C., Weisenborn J.L.F., Ashworth M.P., Kurzydłowski K.J., Zgłobicka I., Dobosz S. (2014) Description of Biremis panamae sp. nov., a new diatom species from the marine littoral, with an account of the phylogenetic position of Biremis D.G. Mann et E.J. Cox (Bacillariophyceae). PLoS ONE 9: e114508. https://doi.org/10.1371/journal.pone.0114508

Creative Commons License

This work is licensed under a Creative Commons Attribution 4.0 International License.