Plant Ecology and Evolution 152(2): 351-357, doi: 10.5091/plecevo.2019.1598
Polymorphism in Mastogloia (Bacillariophyceae) revisited
expand article infoMark Edlund, David R.L. Burge§
‡ Science Museum of Minnesota, Marine on St. Croix, Minnesota, United States of America§ Water Resources Science, University of Minnesota, St. Paul, Minnesota, 55108, United States of America
Open Access

Background and aimsMastogloia grevillei has been shown to be a polymorphic diatom species, producing frustules with morphology of Mastogloia grevillei, frustules with morphology of M. danseyi, and more rarely, heteromorphic or Janus cells with one valve of each morphology.

Methods – We investigated a wetland population from Iowa (USA) known to produce heteromorphic valves and the type material of Mastogloia grevillei and M. danseyi to clarify the nomenclature of this taxon.

Key results – The polymorphic shift in stria construction and density between Mastogloia grevillei and M. danseyi occurs in populations sampled decades apart, among widely separated populations, within single genotypes, and independent of sexual reproduction. Combining our observations with observations of type material for Mastogloia grevillei and M. danseyi we propose that Mastogloia danseyi f. grevillei stat. nov. be recognized as an ecophenotype of the nominate Mastogloia danseyi, as the latter taxon has nomenclatural priority. We also provide lectotypes for both taxa.

Conclusions – Variability in stria structure and density between the two taxa is discontinuous and represents a probable polyphenism for diatoms that is likely triggered by changing total dissolved solids, conductivity, and/or solutes.

Bacillariophyta, diatoms, ecophenotype, Janus cells, morphological variation, nomenclature, phenotypic plasticity, polyphenism, taxonomy


  • Belcher J.H., Swale E.M.F., Heron J. (1966) Ecological and morphological observations on a population of Cyclotella pseudostelligera. Journal of Ecology 54: 335–340.
  • Bentley K., Clack C., Cox E.J. (2012) Diatom colony formation: A computational study predicts a single mechanism can produce both linkage and separation valves due to an environmental switch. Journal of Phycology 48: 716–728.
  • Burge D., Edlund M.B. (2016) Stephanodiscus hantzschii. In: Diatoms of North America [online]. Available from [accessed 20 Jul. 2018].
  • Cox E.J. (1995) Morphological variation in widely distributed diatom taxa: taxonomic and ecological implications. In: Marino D., Montresor M. (eds) Proceedings of the Thirteenth International Diatom Symposium: 335–345. Bristol, Biopress.
  • Cox E.J. (1997) Assessing and designating taxa at or below the species level–a consideration of current status and some suggested guidelines for the future. Nova Hedwigia 65: 13–26.
  • Cox E.J. (2011) Morphology, cell wall, cytology, ultrastructure and morphogenetic studies. In: Seckbach J., Kociolek P. (eds) The Diatom World: 21–45. Dordrecht, Springer.
  • 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.
  • Cox E.J. (2014) Diatom identification in the face of changing species concepts and evidence of phenotypic plasticity. Journal of Micropaleontology 33: 111–120.
  • Czarnecki D.B. (1987) Mastogloia revisited: Laboratory confirmation of Stoermer’s observation. IX North American Diatom Symposium, Abstracts No. 7, Treehaven Field Station, Tomahawk, Wisconsin.
  • Czarnecki D.B. (1994) The freshwater diatom culture collection at Loras College, Dubuque, Iowa. In: Kociolek J.P. (ed.) Proceedings of the Eleventh International Diatom Symposium, Memoirs of the California Academy of Sciences, Number 17: 155–173. San Francisco, California Academy of Sciences.
  • Edlund M.B. (1992) Silica-related morphological variation in natural and cultured populations of Stephanodiscus niagarae (Bacillariophyta). M.Sc. thesis, University of Michigan, Ann Arbor, USA.
  • English J.D., Potapova M.G. (2012) Ontogenetic and interspecific valve shape variation in the Pinnatae group of the genus Surirella and the description of S. lacrimula sp. nov. Diatom Research 27: 9–27.
  • Geitler L. (1932) Der Formwechsel der pennaten Diatomeen. Archiv für Protistenkunde 78: 1–227.
  • Gregory W. (1856) Notice of some new species of British fresh-water Diatomaceae. Quarterly Journal of Microscopical Science, New Series 4: 1–14, pl. I.
  • Gsell A.S., Senerpont Domis L.N., Przytulska‐Bartosiewicz A., Mooij W.M., Donk E., Ibelings B.W. (2012) Genotype-by-temperature interactions may help to maintain clonal diversity in Asterionella formosa (Bacillariophyceae). Journal of Phycology 48: 1197–1208.
  • Håkansson H., Stoermer E.F. (1984) Observations on the type material of Stephanodiscus hantzschii Grunow in Cleve & Grunow. Nova Hedwigia 39: 477–495.
  • Hevia-Orube J., Orive E., David H., Díez A., Laza-Martínez A., Miguel I., Seoane S. (2016) Molecular and morphological analyses of solitary forms of brackish thalassiosiroid diatoms (Coscinodiscophyceae), with emphasis on their phenotypic plasticity. European Journal of Phycology 51: 11–30.
  • Hurley C. (1987) Polymorphism in the diatom genus Mastogloia. Senior thesis, Loras College, Dubuque, Iowa, USA.
  • Hustedt F. (1930) Bacillariophyta (Diatomeae). In: Pascher A. (ed.) Die Süsswasserflora Mitteleuropas, Heft 10. 2nd Edition. Stuttgart, Gustav Fischer.
  • Kaczmarska I., Poulíčková A., Sato S., Edlund M.B., Idei M., Watanabe T., Mann D.G. (2013) Proposals for a terminology for diatom sexual reproduction, auxospores and resting stages. Diatom Research 28: 263–294.
  • Krammer K., Lange-Bertalot H. (1986) Bacillariophyceae 1. Teil: Naviculaceae. In: Ettl H., Gerloff J., Heynig H., Mollenhauer D. (eds) Süsswasserflora von Mitteleuropa, vol. 2/1. Stuttgart, Gustav Fisher Verlag.
  • Main S.P. (1995) Observations of auxospore production and initial cell formation in Mastogloia grevillei. In: Kociolek J.P., Sullivan M.J. (eds) A century of diatom research in North America: a tribute to the distinguished careers of Charles W. Reimer and Ruth Patrick: 79–86. Champaign, Illinois, Koeltz Scientific Books USA.
  • McLachlan J. (1973) Growth media – marine. In: Stein J.R. (ed.) Handbook of Phycological Methods. I. Culture methods and growth measurements: 25–51. Cambridge, Cambridge University Press.
  • 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.
  • Sackett O., Petrou K., Reedy B., De Grazia A., Hill R., Doblin M., Beardall J., Ralph P., Heraud P. (2013) Phenotypic plasticity of Southern Ocean diatoms: Key to success in the sea ice habitat? PLoS ONE 8: e81185.
  • Smith W. (1856) A Synopsis of the British Diatomaceae; with remarks on their structure, functions and distribution; and instructions for collecting and preserving specimens. Vol. 2 pp. [i-vi] – xxix, 1–107, pls 32–60, 61–62, A–E. London, John van Voorst.
  • Stoermer E.F. (1967) Polymorphism in Mastogloia. Journal of Phycology 3: 73–77.
  • Stoermer E.F., Emmert G., Schelske C.L. (1989) Morphological variation of Stephanodiscus niagarae Ehr. (Bacillariophyta) in a Lake Ontario sediment core. Journal of Paleolimnology 2: 227–236.
  • Stoermer E.F., Edlund M.B., Pilskaln C.H., Schelske C.L. (1995) Siliceous microfossil distribution in the surficial sediments of Lake Baikal. Journal of Paleolimnology 14: 69–82.
  • Teubner R. (1995) A light microscopical investigation and multivariate statistical analyses of heterovalvar cells of Cyclotella-species (Bacillariophyceae) from lakes of the Berlin-Brandenburg region. Diatom Research 10: 191–205.
  • Thwaites G.H.K. (1848) Further observations on the Diatomaceae with descriptions of new genera and species. Annals and Magazine of Natural History, Series 2, 1: 161–172, pls XI, XII.
  • Tuchman M.L., Theriot E., Stoermer E.F. (1984) Effects of low level salinity concentrations on the growth on Cyclotella meneghiniana Kütz. (Bacillariophyta). Archiv für Protistenkunde 128: 319–326.
  • Turland N.J., Wiersema J.H., Barrie F.R., Greuter W., Hawksworth D.L., Herendeen P.S., Knapp S., Kusber W.-H., Li D.-Z., Marhold K., May T.W., McNeill J., Monro A.M., Prado J., Price M.J., Smith G.F. (eds) (2018) International Code of Nomenclature for algae, fungi, and plants (Shenzhen Code) adopted by the Nineteenth International Botanical Congress Shenzhen, China, July 2017. Regnum Vegetabile 159. Glashütten, Koeltz Botanical Books.
  • Walls J. (2016) Gomphonema sarcophagus. In: Diatoms of North America [online]. Available from [accessed 20 Sept. 2018].
  • Wolf K.K., Hoppe C.J., Rost B. (2018) Resilience by diversity: Large intraspecific differences in climate change responses of an Arctic diatom. Limnology and Oceanography 63: 397–411.
  • Zhu Z., Qu P., Gale J., Fu F., Hutchins D.A. (2017) Individual and interactive effects of warming and CO2 on Pseudo-nitzschia subcurvata and Phaeocystis antarctica, two dominant phytoplankton from the Ross Sea, Antarctica. Biogeosciences 14: 5281–5295.