Abstract
Cymbopleura huohuaensis sp. nov. is identified as a new species and described from stone surfaces in Huohua Lake, Sichuan Province, China. A detailed morphological description of the new species is presented, based on light and scanning electron microscopy. Cymbopleura huohuaensis sp. nov. has the features that assign it to the genus Cymbopleura, including the raphe with dorsally deflected terminal fissures and ventrally curved central raphe ends, punctate-lineate striae, and the absence of apical pore fields and stigmata. There are five features that easily distinguish the new species from the other similar taxa within the genus: 1) linear-lanceolate central area, 2) mostly slit-like, partly T-shaped, V-shaped or irregularly-shaped areolae, 3) strongly reverse-lateral raphe, 4) slightly truncate to obtusely rounded ends and 5) the highest density of areolae (30–50 in 10 μm). Among the currently described species of Cymbopleura, the new species is in general most similar to C. subaequalis var. pertruncata in valve shape and possessing a reverse-lateral raphe, but is easily distinguished from that taxon by the size and shape of valve, shape of central area, and the degree of asymmetry about the apical axis and its notable lack of an intermissio. This species might be better placed in the C. austriaca group due to its lack of an intermissio. These findings increase our understanding the morphology and distribution of the genus Cymbopleura in China.
References
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<p>Bahls, L.L. (2019) New combinations for diatoms (Bacillariophyta) from the Cascadia Bioregion of North America. <em>Notulae Algarum</em> 114: 1.</p>
<p>Battarbee, R.W. (1986) Diatom analysis. <em>In:</em> Norton, S.A. (Ed.) <em>Handbook of Holocene Palaeoecology & Palaeohydrology</em>. John Wiley and Sons: Chichester, UK, pp. 527–570.</p>
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<p>Cleve, P.T. (1894) Synopsis of the Naviculoid Diatoms.<em> In: </em>PA Norstedt & söner <em>Part I. Kongliga Svenska-Vetenskaps Akademiens Handlingar</em> 26 (2): 1–194.</p>
<p>Czarnecki, D.B. (1994) The freshwater diatom culture collection at Loras College, Dubuque, Iowa. <em>Memoirs of the California Academy of Sciences</em> 17: 155–174.</p>
<p>Delgado, C., Ector, L., Novais, M.H., Blanco Lanza, S., Hoffmann, L. & Pardo, I. (2013) Epilithic diatoms of springs and spring-fed streams in Majorca Island (Spain) with the description of a new diatom species <em>Cymbopleura margalefii</em> <em>sp. nov.</em> <em>Fottea </em>13 (2): 87–104. https://doi.org/10.5507/fot.2013.009</p>
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<p>Kociolek, J.P., Balasubramanian, K., Blanco, S., Coste, M., Ector, L., Liu, Y., Karthick, B., Kulikovskiy, M., Lundholm, N., Ludwig, T., Potapova, M., Rimet, F., Sabbe, K., Sala, S., Sar, E., Taylor, J., Van de Vijver, B., Wetzel, C.E., Williams, D.M., Witkowski, A. & Witkowski, J. (2021) Diatombase. [WWW document] URL https://www.diatombase.org (accessed 9 October 2021)</p>
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<p>Krammer, K. (1997a) Die cymbelloiden Diatomeen. Eine Monographie der weltweit bekannten Taxa. Teil 1. <em>Allgemeines</em> und <em>Encyonema</em> Part. <em>Bibliotheca Diatomologica</em> 36: 1–382.</p>
<p>Krammer, K. (1997b) Die cymbelloiden Diatomeen. Eine Monographie der weltweit bekannten Taxa. Teil 2. <em>Encyonema</em> part, <em>Encyonopsis</em> and <em>Cymbellopsis</em>. <em>Bibliotheca Diatomologica</em> 37: 1–469.</p>
<p>Krammer, K. (1999) Validierung von <em>Cymbopleura</em> nov. gen. <em>Iconographia Diatomologica</em> 6: 1–292.</p>
<p>Krammer, K. (2003) <em>Cymbopleura, Delicata, Navicymbula, Gomphocymbellopsis, Afrocymbella. In:</em> Lange-Bertalot, H. (Ed.) <em>Diatoms of Europe.</em> <em>Vol. 4: Diatoms of the European inland waters and comparable habitats elsewhere.</em> ARG Gantner Verlag KG, Ruggell, 530 pp.</p>
<p>Lange-Bertalot, H. & Genkal, S.I. (1999) Diatoms from Siberia I. Islands in the Arctic Ocean (Yugorsky-Shar Strait). <em>Iconographia Diatomologica</em> 6: 1–293 (2nd corrected printing).</p>
<p>Le Cohu, R., Lange-Bertalot, H. & Azemar, F. (2011) <em>Cymbopleura pyrenaica</em> <em>sp. nov.</em> (Bacillariophyceae) and some other <em>Cymbopleura</em> species rarely observed in some lakes of the French Pyrenees. <em>Cryptogamie Algologie</em> 32: 337–349. https://doi.org/10.7872/crya.v32.iss4.2011.337</p>
<p>Levkov, Z., Krstic, S., Metzeltin, D. & Nakov, T. (2007) Diatoms of Lake Prespa and Ohrid. About 500 taxa from ancient lake system. <em>Iconographia Diatomologica</em> 16: 1–613.</p>
<p>Li, Y., Gong, Z., Xie, P. & Shen, J. (2007) New species and new records of fossil diatoms from China. <em>Acta Hydrobiologica Sinica</em> 31 (3): 323.</p>
<p>Liu, Y., Wang, Q. & Shi, Z.X. (2007) Newly recorded species of Cymbellaceae (Bacillariophyta) from Da’erbin Lake, Daxing’anling Mountains, China. <em>Journal of Wuhan Botanical Research</em> 25: 565–571. [In Chinese with English abstract]</p>
<p>Liu, Y., Fan, Y.W. & Wang, Q.X. (2012) A new record of Cymbellaceae and Gomphonemaceae from Daxing’anling, China. <em>Chinese Journal of Hydrobiology</em> 36: 496–508. [In Chinese with English abstract]</p>
<p>Lyngbye, H.C. (1819) <em>Tentamen Hydrophytologiae Danicae Continens omnia Hydrophyta Cryptogama Daniae, Holsatiae, Faeroae, Islandiae, Groenlandiae hucusque cognita, Systematice Disposita, Descripta et iconibus illustrata, Adjectis Simul Speciebus Norvegicis</em>. Hafniae, Typis Schultzianis, in commissis Librariae Gyldendaliae, Copenhagen, 248 pp. http://dx.doi.org/10.5962/bhl.title.6079</p>
<p>Manguin, E. (1961) Contribution à la flore diatomique de l’Alaska: Lac Karluk, espèces critiques ou nouvelles. <em>Revue Algologique, Nouvelle Série</em> 5: 266–288.</p>
<p>Metzeltin, D. & Lange-Bertalot, H. (2007) Tropical Diatoms of South America II. Special remarks on biogeographic disjunction. <em>Iconographia Diatomologica</em> 18: 1–877.</p>
<p>Metzeltin, D., Lange-Bertalot, H. & Nergui, S. (2009) Diatoms in Mongolia. <em>Iconographia Diatomologica</em> 20: 1–648.</p>
<p>Shi, Z.X. (2013) Bacillariophyta, Cymbellaceae. <em>In</em>: <em>Flora Algarum Sinicarum Aquae Dulcis</em>. Science Press, Tomus, XVI. [In Chinese with English abstract]</p>
<p>Tan, J. & Wu, L. (2017) Sichuan: an important cradle of Chinese silk civilization. <em>Contemporary Social Sciences</em> 2 (06): 22–28.</p>
<p>Van de Vijver, B., Jüttner, I., Gurung, S., Sharma, C., Sharma, S., de Haan, M. & Cox, E.J. (2011) The genus <em>Cymbopleura</em> (Cymbellales, Bacillariophyta) from high altitude freshwater habitats, Everest National Park, Nepal, with the description of two new species. <em>Fottea</em> 11 (2): 245–269. https://doi.org/10.5507/fot.2011.025</p>
<p>Van Heurck, H. (1880) <em>Synopsis des diatomées de Belgique.</em> Atlas. Ducaju & Cie., Anvers. 61 pp.</p>
<p>Wang, Q.X. & Deng, G.P. (2017) Atlas of Algae in Jiuzhaigou Nature Reserve. Science Press, Beijing, 144 pp. [In Chinese with English abstract]</p>
<p>Wu, W.W., Liu, Q., Feng, J., Lu, J.P. & Xie, S.L. (2017) The classification of diatoms in Lalu wetland in Tibet. <em>Acta Botanica Boreali-Occidentalia Sinica</em> 37: 613–618. [In Chinese with English abstract]</p>
<p>Wynne, M.J. (2019) <em>Delicatophycus</em> <em>gen. nov.</em>: a validation of “<em>Delicata</em> Krammer” inval. Gomphonemataceae, Bacillariophyta). <em>Notulae Algarum</em> 97: 1–3.</p>
<p>Bahls, L.L. (2013) New diatoms (Bacillariophyta) from western North America. <em>Phytotaxa</em> 82: 7–28. https://doi.org/10.11646/phytotaxa.82.1.2</p>
<p>Bahls, L.L. (2014) New diatoms from the American West—A tribute to citizen science. <em>Proceedings of the Academy of Natural Sciences of Philadelphia</em> 163: 61–84. https://doi.org/10.1635/053.163.0109</p>
<p>Bahls, L.L. & Luna, T. (2018) <em>Cymbopleura laszlorum</em> <em>spec. nov.</em> (Cymbellaceae, Bacillariophyceae), a glacial relic from a calcium-rich floodplain fen in southwestern Montana, USA. <em>Phytotaxa</em> 349: 47–53. https://doi.org/10.11646/phytotaxa.349.1.5</p>
<p>Bahls, L.L. (2019) New combinations for diatoms (Bacillariophyta) from the Cascadia Bioregion of North America. <em>Notulae Algarum</em> 114: 1.</p>
<p>Battarbee, R.W. (1986) Diatom analysis. <em>In:</em> Norton, S.A. (Ed.) <em>Handbook of Holocene Palaeoecology & Palaeohydrology</em>. John Wiley and Sons: Chichester, UK, pp. 527–570.</p>
<p>Brébisson, A. de. (1838) <em>Considérations sur les Diatomées et essai d'une classification des genres et des espèces appartenant à cette famille</em>. Brée l'Ainé Imprimeur-Libraire, Falaise. 22 pp.</p>
<p>Cleve, P.T. (1894) Synopsis of the Naviculoid Diatoms.<em> In: </em>PA Norstedt & söner <em>Part I. Kongliga Svenska-Vetenskaps Akademiens Handlingar</em> 26 (2): 1–194.</p>
<p>Czarnecki, D.B. (1994) The freshwater diatom culture collection at Loras College, Dubuque, Iowa. <em>Memoirs of the California Academy of Sciences</em> 17: 155–174.</p>
<p>Delgado, C., Ector, L., Novais, M.H., Blanco Lanza, S., Hoffmann, L. & Pardo, I. (2013) Epilithic diatoms of springs and spring-fed streams in Majorca Island (Spain) with the description of a new diatom species <em>Cymbopleura margalefii</em> <em>sp. nov.</em> <em>Fottea </em>13 (2): 87–104. https://doi.org/10.5507/fot.2013.009</p>
<p>Ehrenberg, C.G. (1832) <em>Über die Entwickelung und Lebensdauer der Infusionsthiere; nebst ferneren Beiträgen zu einer Vergleichung ihrer organischen Systeme</em>. Abhandlungen der Königlichen Akademie Wissenschaften zu Berlin, Physikalische Klasse, 154 pp.</p>
<p>Ge, L., Liu, Y. & Fan, Y.W. (2013) Newly recorded species of Cymbellaceae and Gomphonemataceae (Bacillariophyta) from Xingkai Lake, China. <em>Acta Botanica Boreali-Occidentalia Sinica</em> 33: 2131–2135. [In Chinese with English abstract]</p>
<p>Gong, Z.J., Li, Y.L., Metzeltin, D. & Lange-Bertalot, H. (2013) New species of <em>Cymbella</em> and <em>Placoneis</em> (Bacillariophyta) from late Pleistocene Fossil, China. <em>Phytotaxa</em> 150: 29–40. http://doi.org/10.11646/phytotaxa.150.1.2</p>
<p>Greville, R.K. (1833) Diatomaceae. <em>In</em>: Smith, J.E. & Hooker, W.J. (Eds.) <em>The English Flora of Sir James Edward Smith</em>. Longman, Brown, Green & Longmans Paternoster-Row, London, pp. 1824–1836.</p>
<p>Haeckel, E. (1878) <em>Das Protistenreich. Eine Populäre Uebersicht über das Formengebiet der Niedersten Lebewesen. </em>Ernst Günther's Verlag, Leipzig, 104 pp. https://doi.org/10.5962/bhl.title.58542</p>
<p>Hu, Z.J., Li, Y.L. & Wang, Y. (2015) New records of Cymbellaceae (Bacillariophyta) in China. <em>Acta Palaeontologica Sinica</em> 54 (01): 140–146. [In Chinese with English abstract]</p>
<p>Kociolek, J.P. & de Reviers, B. (1996) The diatom types of Emile Manguin. I. Validating descriptions and designation of iconotypes for the Lake Karluk species. <em>Cryptogamie, Algologie</em> 17: 175–191.</p>
<p>Kociolek, J.P., Balasubramanian, K., Blanco, S., Coste, M., Ector, L., Liu, Y., Karthick, B., Kulikovskiy, M., Lundholm, N., Ludwig, T., Potapova, M., Rimet, F., Sabbe, K., Sala, S., Sar, E., Taylor, J., Van de Vijver, B., Wetzel, C.E., Williams, D.M., Witkowski, A. & Witkowski, J. (2021) Diatombase. [WWW document] URL https://www.diatombase.org (accessed 9 October 2021)</p>
<p>Krammer, K. (1982a) Valve morphology in the genus <em>Cymbella</em> C.A. Agardh.<em> In: </em>Helmcke, J.-G. & Krammer, K. (Ed.) <em>Micromorphology of diatom valves</em>. J. Cramer, Vaduz, Vol 11. 299 pp.</p>
<p>Krammer, K. (1997a) Die cymbelloiden Diatomeen. Eine Monographie der weltweit bekannten Taxa. Teil 1. <em>Allgemeines</em> und <em>Encyonema</em> Part. <em>Bibliotheca Diatomologica</em> 36: 1–382.</p>
<p>Krammer, K. (1997b) Die cymbelloiden Diatomeen. Eine Monographie der weltweit bekannten Taxa. Teil 2. <em>Encyonema</em> part, <em>Encyonopsis</em> and <em>Cymbellopsis</em>. <em>Bibliotheca Diatomologica</em> 37: 1–469.</p>
<p>Krammer, K. (1999) Validierung von <em>Cymbopleura</em> nov. gen. <em>Iconographia Diatomologica</em> 6: 1–292.</p>
<p>Krammer, K. (2003) <em>Cymbopleura, Delicata, Navicymbula, Gomphocymbellopsis, Afrocymbella. In:</em> Lange-Bertalot, H. (Ed.) <em>Diatoms of Europe.</em> <em>Vol. 4: Diatoms of the European inland waters and comparable habitats elsewhere.</em> ARG Gantner Verlag KG, Ruggell, 530 pp.</p>
<p>Lange-Bertalot, H. & Genkal, S.I. (1999) Diatoms from Siberia I. Islands in the Arctic Ocean (Yugorsky-Shar Strait). <em>Iconographia Diatomologica</em> 6: 1–293 (2nd corrected printing).</p>
<p>Le Cohu, R., Lange-Bertalot, H. & Azemar, F. (2011) <em>Cymbopleura pyrenaica</em> <em>sp. nov.</em> (Bacillariophyceae) and some other <em>Cymbopleura</em> species rarely observed in some lakes of the French Pyrenees. <em>Cryptogamie Algologie</em> 32: 337–349. https://doi.org/10.7872/crya.v32.iss4.2011.337</p>
<p>Levkov, Z., Krstic, S., Metzeltin, D. & Nakov, T. (2007) Diatoms of Lake Prespa and Ohrid. About 500 taxa from ancient lake system. <em>Iconographia Diatomologica</em> 16: 1–613.</p>
<p>Li, Y., Gong, Z., Xie, P. & Shen, J. (2007) New species and new records of fossil diatoms from China. <em>Acta Hydrobiologica Sinica</em> 31 (3): 323.</p>
<p>Liu, Y., Wang, Q. & Shi, Z.X. (2007) Newly recorded species of Cymbellaceae (Bacillariophyta) from Da’erbin Lake, Daxing’anling Mountains, China. <em>Journal of Wuhan Botanical Research</em> 25: 565–571. [In Chinese with English abstract]</p>
<p>Liu, Y., Fan, Y.W. & Wang, Q.X. (2012) A new record of Cymbellaceae and Gomphonemaceae from Daxing’anling, China. <em>Chinese Journal of Hydrobiology</em> 36: 496–508. [In Chinese with English abstract]</p>
<p>Lyngbye, H.C. (1819) <em>Tentamen Hydrophytologiae Danicae Continens omnia Hydrophyta Cryptogama Daniae, Holsatiae, Faeroae, Islandiae, Groenlandiae hucusque cognita, Systematice Disposita, Descripta et iconibus illustrata, Adjectis Simul Speciebus Norvegicis</em>. Hafniae, Typis Schultzianis, in commissis Librariae Gyldendaliae, Copenhagen, 248 pp. http://dx.doi.org/10.5962/bhl.title.6079</p>
<p>Manguin, E. (1961) Contribution à la flore diatomique de l’Alaska: Lac Karluk, espèces critiques ou nouvelles. <em>Revue Algologique, Nouvelle Série</em> 5: 266–288.</p>
<p>Metzeltin, D. & Lange-Bertalot, H. (2007) Tropical Diatoms of South America II. Special remarks on biogeographic disjunction. <em>Iconographia Diatomologica</em> 18: 1–877.</p>
<p>Metzeltin, D., Lange-Bertalot, H. & Nergui, S. (2009) Diatoms in Mongolia. <em>Iconographia Diatomologica</em> 20: 1–648.</p>
<p>Shi, Z.X. (2013) Bacillariophyta, Cymbellaceae. <em>In</em>: <em>Flora Algarum Sinicarum Aquae Dulcis</em>. Science Press, Tomus, XVI. [In Chinese with English abstract]</p>
<p>Tan, J. & Wu, L. (2017) Sichuan: an important cradle of Chinese silk civilization. <em>Contemporary Social Sciences</em> 2 (06): 22–28.</p>
<p>Van de Vijver, B., Jüttner, I., Gurung, S., Sharma, C., Sharma, S., de Haan, M. & Cox, E.J. (2011) The genus <em>Cymbopleura</em> (Cymbellales, Bacillariophyta) from high altitude freshwater habitats, Everest National Park, Nepal, with the description of two new species. <em>Fottea</em> 11 (2): 245–269. https://doi.org/10.5507/fot.2011.025</p>
<p>Van Heurck, H. (1880) <em>Synopsis des diatomées de Belgique.</em> Atlas. Ducaju & Cie., Anvers. 61 pp.</p>
<p>Wang, Q.X. & Deng, G.P. (2017) Atlas of Algae in Jiuzhaigou Nature Reserve. Science Press, Beijing, 144 pp. [In Chinese with English abstract]</p>
<p>Wu, W.W., Liu, Q., Feng, J., Lu, J.P. & Xie, S.L. (2017) The classification of diatoms in Lalu wetland in Tibet. <em>Acta Botanica Boreali-Occidentalia Sinica</em> 37: 613–618. [In Chinese with English abstract]</p>
<p>Wynne, M.J. (2019) <em>Delicatophycus</em> <em>gen. nov.</em>: a validation of “<em>Delicata</em> Krammer” inval. Gomphonemataceae, Bacillariophyta). <em>Notulae Algarum</em> 97: 1–3.</p>