Abstract
Two diatom species from Ethiopian freshwater ecosystems, Sellaphora ashinovii sp. nov. and Planothidium paisiusii sp. nov., are described as new to science. Their morphology and molecular characteristics were analysed to establish their taxonomic position. Comparisons with closely related taxa and results of molecular analyses are presented. This study adds to the limited molecular information available on African diatoms and highlights the need for further molecular surveys across the continent.
References
- Andreeva, S., Kociolek, J.P., Maltsev, E., Dorofeyuk, N., Kezlya, E., Shkurina, N., Kuznetsova, I., Gusev, E. & Kulikovskiy, M. (2018) Sellaphora balashovae (Bacillariophyta), a new species from Siberian mountain Lake Frolikha (Baikal region), Russia. Phytotaxa 371 (2): 73–83. https://doi.org/10.11646/phytotaxa.371.2.1
- Beyene, A. & Triest, L. (2009) Diatom Community Response to Pollution in Ethiopian Rivers. In: Symposium on African Botany. Brussels, Belgium. http://dx.doi.org/10.13140/2.1.4499.1361
- Brendemühl, I. (1949) Über die Verbreitung der Erddiatomeen. Archiv für Mikrobiologie 14 (3): 407–449.
- Cocquyt, C. & Ryken, E. (2016) Afrocymbella barkeri sp. nov. (Bacillariophyta), a common phytoplankton component of Lake Challa, a deep crater lake in East Africa. European Journal of Phycology 51 (2): 217–225. https://doi.org/10.1080/09670262.2015.1126766
- Darriba, D., Taboada, G.L., Doallo, R. & Posada, D. (2012) jModelTest 2: More models, new heuristics and parallel computing. Nature Methods 9: 772. https://doi.org/10.1038/nmeth.2109
- Drummond, A.J. & Rambaut, A. (2007) BEAST: Bayesian evolutionary analysis by sampling trees. BMC Ecology and Evolution 7: 214. https://doi.org/10.1186/1471-2148-7-214
- Ehrenberg, C.G. (1845) Mitteilungen über die mikroskopischen Lebensformen von Portugal und Spanien, Süd-Afrika, Hinter-Indien, Japan und Kurdistan. Noverum generum et specierum brevis definitio. Bericht über die zur Bekanntmachung geeigneten Verhandlungen der Königlich Preussischen Akademie der Wissenschaften zu Berlin 1845: 357–381.
- Evans, K.M., Chepurnov, V.A., Sluiman, H.J., Thomas, S.J., Spears, B.M. & Mann, D.G. (2009) Highly differentiated populations of the freshwater diatom Sellaphora capitata suggest limited dispersal and opportunities for allopatric speciation. Protist 160 (3): 386–396. https://doi.org/10.1016/j.protis.2009.02.001
- 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 (1): 215–231. https://doi.org/10.1111/j.1529-8817.2007.00454.x
- 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 (3): 349–364. https://doi.org/10.1016/j.protis.2007.04.001
- Foets, J. & Wetzel, C.E. (2018) Sellaphora harderi (Hustedt) comb. nov. (Bacillariophyta, Sellaphoraceae), an overlooked terrestrial diatom. Notulae Algarum 52: 1–5.
- Gasse, F. (1974a) Les Diatomées des sédiments Holocène du Bassin du lac Afrera (Guilietti) (Afar Septentrional, Ethiopie). Internationale Revue der gesamten Hydrobiologie 59 (1): 95–122. https://doi.org/10.1002/iroh.19740590112
- Gasse, F. (1974b) Ultrastructure de quelques Diatomées centriques fossiles d’ Éthiopie, révelée par le microscope électronique a balayage. Revue Algologique, Nouvelle Série XI: 137–153.
- Gasse, F. & Tékaïa, F. (1979) La paléoécologie des diatomées: évolution des lacs de l’Afar central. Les cahiers de l’analyse des données 4 (1): 81–94.
- Glushchenko, A., Genkal, S., Kuznetsova, I. & Kulikovskiy, M. (2023) Taxonomy and Distribution of the Genus Sellaphora Mereschowsky (Bacillariophyceae: Sellaphoraceae) in Aquatic Ecosystems of Mongolia. Plants 12: 3611. https://doi.org/10.3390/plants12203611
- Glushchenko, A., Kezlya, E., Maltsev, Y., Genkal, S., Kociolek, J.P. & Kulikovskiy, M. (2022) Description of the soil diatom Sellaphora terrestris sp. nov. (Bacillariophyceae, Sellaphoraceae) from Vietnam, with remarks on the phylogeny and taxonomy of Sellaphora and systematic position of Microcostatus. Plants 11 (2148): 1–22. https://doi.org/10.3390/plants11162148
- Grady, D., Mann, D.G. & Trobajo, R. (2020) Nitzschia fenestralis: A new diatom species abundant in the Holocene sediments of an eastern African crater lake. Fottea 20 (1): 36–48. https://doi.org/10.5507/fot.2019.011
- Guillard, R.R.L. & Lorenzen, C.J. (1972) Yellow-green algae with chlorophyllide c1,2. Journal of Phycology 8: 10–14. https://doi.org/10.1111/j.1529-8817.1972.tb03995.x
- Guiry, M.D. & Guiry, G.M. (2025) AlgaeBase. World-wide electronic publication, University of Galway. Available from: https://www.algaebase.org (accessed 21 March 2025)
- Hunegnaw, Y. & Getaneh, W. (2024) Geology, mineralogy, geochemistry and genesis of volcano-sedimentary hosted Lake Abiyata diatomite in central main Ethiopian Rift. Heliyon 10: e36132. https://doi.org/10.1016/j.heliyon.2024.e36132
- Jahn, R., Abarca, N., Gemeinholzer, B., Mora, D., Skibbe, O., Kulikovskiy, M., Gusev, E., Kusber, W.-H. & Zimmermann, J. (2017) Planothidium lanceolatum and Planothidium frequentissimum reinvestigated with molecular methods and morphology: four new species and the taxonomic importance of the sinus and cavum. Diatom Research 32 (1): 75–107. https://doi.org/10.1080/0269249X.2017.1312548
- Juchem, D.P., Schimani, K., Holzinger, A., Permann, C., Abarca, N., Skibbe, O., Zimmermann, J., Graeve, M. & Karsten, U. (2023) Lipid degradation and photosynthetic traits after prolonged darkness in four Antarctic benthic diatoms, including the newly described species Planothidium wetzelii sp. nov. Frontiers in Microbiology 14: 1241826. https://doi.org/10.3389/fmicb.2023.1241826
- Junqueira, M.G., Crossetti, L.O. & Wetzel, C.E. (2024) Planothidium minuanum sp. nov., a new diatom (Bacillariophyta) species from southern Brazilian coastal lakes. Phytotaxa 676 (2): 126–138. https://doi.org/10.11646/phytotaxa.676.2.2
- Katoh, K. & Toh, H. (2010) Parallelization of the MAFFT multiple sequence alignment program. Bioinformatics 26: 1899–1900. https://doi.org/10.1093/bioinformatics/btq224
- Kebede, E. & Belay, A. (1994) Species composition and phytoplankton biomass in a tropical African lake (Lake Awassa, Ethiopia). Hydrobiologia 288: 13–32. https://doi.org/10.1007/BF00006802
- Kochoska, H., Zaova, D., Videska, A., Mitic-Kopanja, D., Naumovska, H., Wetzel, C.E., Ector, L. & Levkov, Z. (2021) Sellaphora pelagonica (Bacillariophyceae), a new species from dystrophic ponds in the Republic of North Macedonia. Phytotaxa 496 (2): 121–133. https://doi.org/10.11646/phytotaxa.496.2.2
- Kulikovskiy, M., Maltsev, Y., Glushchenko, A., Kuznetsova, I., Kapustin, D., Gusev, E., Lange-Bertalot, H., Genkal, S. & Kociolek, J.P. (2020) Gogorevia, a new monoraphid diatom genus for Achnanthes exigua and allied taxa (Achnanthidiaceae) described on the basis of an integrated molecular and morphological approach. Journal of Phycology 56 (6): 1601–1613. https://doi.org/10.1111/jpy.13064
- 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
- Kützing, F.T. (1844) Die Kieselschaligen Bacillarien oder Diatomeen. Nordhausen: zu finden bei W. Köhne, 152 pp.
- Lange-Bertalot, H. (1999) Neue Kombinationen von Taxa aus Achnanthes Bory (sensu lato). Iconographia Diatomologica 6: 270–283.
- Lange-Bertalot, H., Hofmann, G., Werum, M. & Cantonati, M. (2017) Freshwater Benthic Diatoms of Central Europe: Over 800 Common Species Used in Ecological Assessment. English edition with updated taxonomy and added species. Koeltz Botanical Books, Schmitten-Oberreifenberg, 942 pp.
- Lange-Bertalot, H., Külbs, K., Lauser, T., Nörpel-Schempp, M. & Willmann, M. (1996) Dokumentation und Revision der von Georg Krasske Beschriebenen Diatomeen-Taxa. Iconographia Diatomologica 3: 1–358.
- Liu, Y., Kociolek, J.P., Lu, X. & Fan, Y. (2020) A new Sellaphora Mereschkowsky species (Bacillariophyceae) from Hainan Island, China, with comments on the current state of the taxonomy and morphology of the genus. Diatom Research 35 (1): 85–98. https://doi.org/10.1080/0269249X.2020.1726470
- Mann, D.G. (1989) The diatom genus Sellaphora: separation from Navicula. British Phycological Journal 24 (1): 1–20. https://doi.org/10.1080/00071618900650011
- Mann, D.G. & Stickle, A.J. (2009) Cytological characteristics of the Sellaphoraceae. Acta Botanica Croatica 68 (2): 239–250.
- 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., Evans, K.M., Chepurnov, V.A. & Nagai, S. (2009) Morphology and formal description of Sellaphora bisexualis sp. nov. (Bacillariophyta). Fottea 9 (2): 199–209. https://doi.org/10.5507/fot.2009.021
- Mann, D.G., McDonald, S.M., Bayer, M.M., Droop, S.J., Chepurnov, V.A., Loke, R.E., Ciobanu, A. & Du Buf, J.H. (2004) The Sellaphora pupula species complex (Bacillariophyceae): morphometric analysis, ultrastructure and mating data provide evidence for five new species. Phycologia 43 (4): 459–482. https://doi.org/10.2216/i0031-8884-43-4-459.1
- 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 (1): 15–78. https://doi.org/10.5507/fot.2008.002
- Mereschkowsky, C. (1902) On Sellaphora, a new genus of diatoms. Annals and Magazine of Natural History 9: 185–195.
- Mohan, J., Stone, J.R. & Campisano, C.J. (2016) Three novel species of Bacillariophyta (Diatoms) belonging to Aulacoseira and Lindavia from the Pliocene Hadar Formation, Afar Depression of Ethiopia. Phytotaxa 272 (4): 235–247. https://doi.org/10.11646/phytotaxa.272.4.1
- Morales, E. (2006) Small Planothidium Round et Bukhtiyarova (Bacillariophyceae) taxa related to P. daui (Foged) Lange-Bertalot from the United States. Diatom Research 21 (2): 325–342. https://doi.org/10.1080/0269249X.2006.9705673
- Ni, H.P., Guo, J.S., Tang, Z.B., Huang, Y.Y., Kociolek, J.P. & Li, Y.L. (2022) Sellaphora tanghongquii sp. nov. (Bacillariophyta, Sellaphoraceae), a new diatom species from the Southern China. Phytotaxa 573 (1): 103–114. https://doi.org/10.11646/phytotaxa.573.1.6
- Novis, P.M., Braidwood, J. & Kilroy, C. (2012) Small diatoms (Bacillariophyta) in cultures from the Styx River, New Zealand, including descriptions of three new species. Phytotaxa 64: 11–45. https://doi.org/10.11646/phytotaxa.64.1.3
- Reichardt, E. (2006) Bemerkenswerte Diatomeenfunde aus Bayern V – Neue und seltene Arten aus der Schwarzachklamm. Berichte der Bayerischen Botanischen Gesellschaft zur Erforschung der heimischen Flora 76: 41–51.
- Roubeix, V., Chalié, F. & Gasse, F. (2014) The diatom Thalassiosira faurii (Gasse) Hasle in the Ziway-Shala lakes (Ethiopia) and implications for paleoclimatic reconstructions: Case study of the Glacial-Holocene transition in East Africa. Palaeogeography, Palaeclimatology, Palaeoecology 402: 104–112. https://doi.org/10.1016/j.palaeo.2014.03.014
- Round, F.E. & Bukhtiyarova, L. (1996) Four new genera based on Achnanthes (Achnanthidium) together with a re-definition of Achnanthidium. Diatom Research 11 (2): 345–361. https://doi.org/10.1080/0269249X.1996.9705389
- Round, F.E., Crawford, R.M. & Mann, D.G. (1990) The diatoms. Biology and morphology of the genera. Cambridge University Press, Cambridge, 747 pp.
- Ruck, E.C. & Theriot, E.C. (2011) Origin and evolution of the canal raphe system in diatoms. Protist 162 (5): 723–737. https://doi.org/10.1016/j.protis.2011.02.003
- Rybak, M., Kochman-Kedziora, N. & Peszek, L. (2021) Description of four new terrestrial diatom species from Luticola and Microcostatus genera from South Africa. PhytoKeys 182: 1–26. https://doi.org/10.3897/phytokeys.181.65326
- Shibabaw, T., Beyene, A., Awoke, A., Tirfie, M., Azage, M. & Triest, L. (2021) Diatom community structure in relation to environmental factors in human influenced rivers and streams in tropical Africa. PLoS ONE 16 (2): e0246043. https://doi.org/10.1371/journal.pone.0246043
- Solak, C.N., Hamilton, P.B., Peszek, Ł., Yilmaz, E., Ertorun, N. & Blanco, S. (2023) A new diatom (Bacillariophyta) species – Sellaphora lucectoriana sp. nov. – from a glacial lake in Kaçkar Mountain (Eastern Blacksea Region), Rize, Republic of Türkiye. Nova Hedwigia 117 (1–4): 203–212. https://doi.org/10.1127/nova_hedwigia/2023/0847
- Stancheva, R. (2019) Planothidium sheathii, a new monoraphid diatom species from rivers in California, USA. Phytotaxa 393 (2): 131–140. https://doi.org/10.11646/phytotaxa.393.2.4
- Stamatakis, A., Hoover, P. & Rougemont, J. (2008) A Rapid Bootstrap Algorithm for the RAxML Web Servers. Systematic Biology 57: 758–771. https://doi.org/10.1080/10635150802429642
- Taylor, J.C., Cocquyt, C. & Walsh, G. (2024) Tropical African diatoms from the Eunotia asterionelloides (Bacillariophyta) species complex, with descriptions of new species. Plant Ecology and Evolution 157 (1): 88–99. https://doi.org/10.5091/plecevo.106779
- Taylor, J.C., Karthick, B., Kociolek, J.P., Wetzel, C.E. & Cocquyt, C. (2014) Actinellopsis murphyi gen. et spec. nov.: A new small celled freshwater diatom (Bacillariophyta, Eunotiales) from Zambia. Phytotaxa 178 (2): 128–137. https://doi.org/10.11646/phytotaxa.178.2.4
- Telford, R.J. & Lamb, H.F. (1998) Groundwater-Mediated Response to Holocene Climatic Change Recorded by the Diatom Stratigraphy of an Ethiopian Crater Lake. Quaternary Research 52: 63–75. https://doi.org/10.1006/qres.1999.2034
- Tseplik, N., Maltsev, Y., Glushchenko, A., Genkal, S. & Kulikovskiy, M. (2024a) Two new Planothidium (Achnanthidiaceae, Bacillariophyceae) species with a sinus from the Kamchatka Peninsula, Russia. Phytotaxa 664 (2): 111–122. https://doi.org/10.11646/phytotaxa.664.2.3
- Tseplik, N., Maltsev, Y., Glushchenko, A., Genkal, S., Mironova, E. & Kulikovskiy, M. (2024b) New cavum-bearing Planothidium (Achnanthidiaceae, Bacillariophyceae) species from the Kamchatka Peninsula, Russia. Phytotaxa 665 (3): 271–281. https://doi.org/10.11646/phytotaxa.665.3.9
- Van de Vijver, B., Frenot, Y. & Beyens, L. (2002) Freshwater diatoms from Ile de la Possession (Crozet Archipelago, Subantarctica). Bibliotheca Diatomologica 46: 1–412.
- Van de Vijver, B., Wetzel, C.E. & Ector, L. (2018) Analysis of the type material of Planothidium delicatulum (Bacillariophyta) with the description of two new Planothidium species from the sub-Antarctic Region. Fottea 18 (2): 200–211. https://doi.org/10.5507/fot.2018.006
- Van de Vijver, B., Wetzel, C., Kopalová, K., Zidarova, R. & Ector, L. (2013) Analysis of the type material of Achnanthidium lanceolatum Brébisson ex Kützing (Bacillariophyta) with the description of two new Planothidium species from the Antarctic Region. Fottea 13 (2): 105–117. https://doi.org/10.5507/fot.2013.010
- Vanormelingen, P., Evans, K.M., Chepurnov, V., Vyverman, W. & Mann, D.G. (2013) Molecular species discovery in the diatom Sellaphora and its congruence with mating trials. Fottea 13 (2): 133–148. https://doi.org/10.5507/fot.2013.012
- Wetzel, C.E., Ector, L., Van de Vijver, B., Compere, P. & Mann, D.G. (2015) Morphology, typification and critical analysis of some ecologically important small naviculoid species (Bacillariophyta). Fottea 15 (2): 203–234. https://doi.org/10.5507/fot.2015.020
- Wetzel, C.E., Van de Vijver, B., Blanco, S. & Ector, L. (2019) On some common and new cavum-bearing Planothidium (Bacillariophyta) species from freshwater. Fottea 19 (1): 50–89. https://doi.org/10.5507/fot.2018.016
- Wondmagegn, T., Mengistou, S. & Barker, P.A. (2019) Testing of the applicability of European diatom indices in the tropical rift valley lake, Lake Hawassa, in Ethiopia. African Journal of Aquatic Science 44 (3): 209–217. https://doi.org/10.2989/16085914.2019.1645640
- Zimmermann, J., Jahn, R. & Gemeinholzer, B. (2011) Barcoding diatoms: Evaluation of the V4 subregion on the 18S rRNA gene, including new primers and protocols. Organisms Diversity & Evolution 11: 173–192. https://doi.org/10.1007/s13127-011-0050-6