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Fallacia californica sp. nov. (Bacillariophyta), a new freshwater diatom species from streams in California, USA



Small naviculoid diatoms remain largely taxonomically unexplored in the United States, due to the inability for clear
differentiation of unique characteristics under light microscope magnification during routine identification. In a recent study of benthic stream diatoms from California and as a part of taxonomy data quality assurance and quality control process it became evident that taxonomic reevaluation of a common Fallacia species is needed. A new small-celled Fallacia species is described here and compared to similar taxa. Nomenclatural and ecological discussions, based on historical and current literature, are presented for each taxon. Type materials were consulted for taxonomic evaluation and comparison. The new taxon is described with light microscopy and scanning electron microscopy. Fallacia californica could be distinguished from other small Fallacia species with coarse areolae by the unique combination of following features: 1) distinct lyre-shaped sternum, 2) asymmetrical central area, and 3) variable central striae with one to four inner areolae absent, and unilateral gap between the central striae on the mantle. The new freshwater species was distributed in warm alkaline waters with medium conductivity and elevated nutrients content.The majority of populations have been recorded in coastal streams, where they could be abundant, but the species could be scattered in other inland running waters as well.


Fallacia, Bacillariophyta, diatom, streams, California, new species, scanning electron microscopy, Algae

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Anonymous (1975) Proposals for a standardization of diatom terminology and diagnoses. Nova Hedwigia, Beihefte 53: 323–354.

Cantonati, M., Kelly, M.G. & Lange-Bertalot, H. (2017) Freshwater Benthic Diatoms of Central Europe. Koeltz Botanical Books, Schmitten-Obereifenberg, Germany, 942 pp.

Ector, L., Wetzel, C.E., Novais, M.H. & Guillard, D. (2015) Atlas des diatomées des rivières des Pays de la Loire et de la Bretagne. DREAL Pays de la Loire, Nantes.

Fetscher, A.E., Busse, L. & Ode, P.R. (2009) Standard Operating Procedures for Collecting Stream Algae Samples and Associated Physical Habitat and Chemical Data for Ambient Bioassessments in California. California State Water Resources Control Board Surface Water Ambient Monitoring Program (SWAMP) Bioassessment SOP 002. (updated May 2010). Available from: http://www. (accessed 19 February 2018)

Genkal, S.I. & Yarushina, M.I. (2017) The Species of the genus Fallacia A.J. Stickle & D.G. Mann (Bacillariophyta) in Russia: morphology, taxonomy, ecology and distribution. International Journal on Algae 19: 99–110.

Guiry, M.D. & Guiry, G.M. (2018) AlgaeBase. World-wide electronic publication, National University of Ireland, Galway. Available from: (accessed 19 February 2018)

Hustedt Diatom Collection EarthCape Database (2006–2015) Version 15.2. EarthCape OY. Available from: (accessed 1 March 2018)

Hustedt, F. (1934) Systematische und ökologische Untersuchungenüber die Diatomeen-Flora von Java, Bali und Sumatra nach dem Material der Deutschen Limnologischen Sunda-Expedition. “Tropische Binnenge wässer, Band VII”. Archiv für Hydrobiologie, Supplement 15: 187–295, pls 13–20.

Hustedt, F. (1937) Systematische und ökologische Untersuchungenüber die Diatomeen-Flora von Java, Bali und Sumatra nach dem Material der Deutschen Limnologischen Sunda-Expedition. “Tropische Binnenge wässer, Band VII”. Archiv für Hydrobiologie, Supplement 15: 187–295, pls 13–20.

Hustedt, F. (1944) Neue und wenigbekannte Diatomeen. Bericht der Deutschen Botanischen Gessellschaft 61: 271–290, 8 pls.

Hustedt, F. (1956) Diatomeenausdem Lago de Maracaibo in Venezuela. In: Ergebnisse der deutschen limnologischen Venezuela-Expedition 1952 (F. Gessner & V. Vareschi). Deutscher Verlag der Wissenschaften, Berlin, pp. 93–140.

Hustedt, F. (1957) Die Diatomeenflora des Flußsystems der Weser im Gebiet der Hansestadt Bremen. Abhandlungen herausgegeben vom Naturwissenschaftlichen Verein zu Bremen 34: 181–440.

Hustedt, F. (1961–1966) Die Kieselalgen Deutschlands, Osterreichs und der Schweiz. In: Dr. L. Rabenhorsts (Ed.) Kryptogamen flora von Deutschland, Österreich und der Schweiz, Band 7, Teil 3. AkademischeVerlagsgesellschaft, Leipzig, 816 pp.

Krammer, K. & Lange-Bertalot, H. (1986) Bacillariophyceae 1. Teil: Naviculaceae. In: Süsswasserflora von Mitteleuropa. Vol. 2 (1). VEB Gustav Fisher Verlag, Jena, pp. 1–876, 206 pls., 2976 figs.

Kulikovskiy, M., Lange-Bertalot, H., Metzeltin, D. & Witkowski, A. (2012) Lake Baikal: hotspot of endemic diatoms I. In: Lange-Bertalot, H. (Ed.) Iconographia Diatomologica. Annotated Diatom Micrographs. Vol. 23. Diversity-Taxonomy-Identification. Koeltz Scientific Books, Königstein, Germany, 861 pp., 156 pls.

Li, Y., Suzuki, H., Nagumo, T. & Tanaka, J. (2014) Auxosporulation, morphology of vegetative cells and perizonium of Fallacia tenera (Hust.) D.G. Mann (Bacillariophyceae). Phytotaxa 164: 239–254.

Li, Y., Suzuki, H., Nagumo, T., Tanaka, J., Sun, Z.& Xu, K. (2015) Fallacia decussata, sp. nov.: a new marine benthic diatom (Bacillariophyceae) from Northeast Asia. Phytotaxa 224: 258–266.

Liu, Y., Kociolek, J.P., Fan, Y. & Wang, Q. (2012) Pseudofallacia gen. nov., a new freshwater diatom (Bacillariophyceae) genus based on Navicula occulta Krasske. Phycologia 51: 620–626.

Manoylov, K.M. (2014) Taxonomic identification of algae (morphological and molecular): species concepts, methodologies, and their implication for ecological bioassessment. Journal of Phycology 50: 409–424.

Metzeltin, D., Lange-Bertalot, H. & García-Rodriguez, F. (2005) Diatoms of Uruguay. Compared with other taxa from South America and elsewhere. Iconographia Diatomologica 15: 1–736.

Miscoe, L.H., Johansen, J.R., Kociolek, J.P. & Lowe, R. (2016) Investigation of the cave diatom flora of Kauai, Hawaii: an emphasis on taxonomy and distribution. Bibliotheca Phycologica 120: 3–74.

Patrick, R. & 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. Philadelphia PA., 688 pp.

Procopiak, L.K. & Fernandes, L.F. (2003) Valve morphology of the benthic diatom Fallacia marnieri (Manguin) Witkowski (Sellaphoraceae-Bacillatiophyta). Brazilian Journal of Biology 63: 113–119.

Ross, R., Cox, E.J., Karayeva, N.I., Mann, D.G., Paddock, T.B.B., Simonsen, R. & Sims, P.A. (1979) An amended terminology for the siliceous components of the diatom cell. Nova Hedwigia, Beihefte 64: 513–533.

Round, F.E., Crawford, R.M. & Mann, D.G. (1990) The Diatoms. Biology and Morphology of the Genera. Cambridge University Press, UK, 747 pp.

Sabbe, K., Vyverman, W. & Muylaert, K. (1999) New and little-known Fallacia species (Bacillariophyta) from brackish and marine intertidal sandy sediments in Northwest Europe and North America. Phycologia 38: 8–22.

Schmidt, A. (1934–1936) Atlas der Diatomaceen-kunde. Leipzig. O.R. Reisland Series VIII (Heft 101–102): pls. 401–408 [F. Hustedt].

Schoeman, F.R. & Archibald, R.E.M. (1979) The Diatom Flora of Southern Africa No.5. CSIR Special Report WAT 50, Pretoria, 65 pp.

Sonneman, J., Sincock, A., Fluin, J., Reid, M., Newall, P.,Tibby, J. & Gell, P.A. (2000) An Illustrated Guide to Common Stream Diatom Species from Temperate Australia. Identification Guide No. 33. Murray—Darling Freshwater Research Centre: Albury.

Spaulding, S.A., Lubinski, D.J. & Potapova, M. (2010) Diatoms of the United States. (accessed 11 November 2017)

Stancheva, R., Busse, L., Kociolek, J.P. & Sheath, R.G. (2015) Standard Operating Procedures for Laboratory Processing and Identification of Stream Algae. California State Water Resources Control Board Surface Water Ambient Monitoring Program (SWAMP) Bioassessment SOP 0003. Available from: (accessed 19 February 2018)

Stancheva, R., Sheath, R.G. & Kociolek, J.P. (2016) New freshwater gomphonemoid diatoms from streams in the Sierra Nevada mountains, California, USA. Phytotaxa 289: 118–134.

Stepanek, J.G. & Kociolek, J.P. (2013) Several new species of Amphora and Halamphora from the western USA. Diatom Research 28: 61–76.

Takano, H. (1990) Semiconical covers in valves of Navicula teneroides Hustedt. Diatom 5: 5–7.

Thomas, E.W. & Kociolek, J.P. (2015) Taxonomy of three new Rhoicosphenia (Bacillariophyta) species from California, USA. Phytotaxa 204: 1–21.

Van Dam, H., Mertenes, A. & Sinkeldam, J. (1994) A coded checklist and ecological indicator values of freshwater diatoms from the Netherlands. Netherlands Journal of Aquatic Ecology 28: 117–33.

Van De Vijver, B. & Cox, E.J. (2015) Fallacia emmae sp. nov., (Bacillariophyta) a new soil-inhabiting diatom species from the Sub-Antarctic Region. Cryptogamie, Algologie 36: 245–254.

USEPA (2013) National Rivers and Streams Assessment 2013-14: Quality Assurance Project Plan. EPA-841-B-12-007.U.S. Environmental Protection Agency, Office of Water, Washington, DC. Available from: (accessed 19 February 2018)

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 (2): 203–234.

Witkowski, A., Lange-Bertalot, H. & Metzeltin, D. (2000) Diatom Flora of Marine Coasts I. In: Lange-Bertalot, H. (Ed.) Iconographia Diatomologica. Vol. 7. Annotated Diatom Micrographs. Diversity-Taxonomy-Identification. Koeltz Scientific Books, Königstein, Germany, 925 pp., 219 pls.

Witkowski, A. (1991) Fallacia cassubiae sp. nov., a new brackish-water diatom from the Puck Bay (Southern Baltic Sea), Poland. Diatom Research 6: 401–409.

Witkowski, A. (1993) Fallacia florinae (Moeller) comb. nov. a marine, epipsammic diatom. Diatom Research 8: 215–219.


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