Tryblionella brunoi (Lange-Bert.) Cantonati et Lange-Bert., 2017

Kusber, Wolf-Henning, Cantonati, Marco & Lange-Bertalot, Horst, 2017, Validation of five diatom novelties published in “ Freshwater Benthic Diatoms of Central Europe ” and taxonomic treatment of the neglected species Tryblionella hantzschiana, Phytotaxa 328 (1), pp. 90-94 : 91-92

Tryblionella brunoi (Lange-Bert.) Cantonati et Lange-Bert. , comb. nov.

≡ Nitzschia brunoi Lange-Bert. in Iconogr. Diatomol. 2: 92, pl. 101: fig. 11–15, pl. 102: fig. 1. 1996.

Type:— AUSTRIA, Mittersee bei Lermoos, Nordtiroler Kalkalpen, K. Külbs KÜ 567, September 1980 (holotype FR, Coll. Lange-Bertalot EU-SF 171!, the holotype is represented by pl. 101: fig. 12 in Lange-Bertalot & Metzeltin (1996).

- Tryblionella brunoi (Lange-Bert.) Cantonati et Lange-Bert. in Lange-Bertalot et al. (2017): 597, nom. inval.; a full and direct citation of the basionym was missing (Art. 41.5, McNeill et al. 2012).

Registration: http://phycobank.org/100111

Tryblionella hantzschiana Grunow in Verh. K. K. Zool.-Bot. Ges. Wien. 12: 551, 552, pl. XVIII: fig. 29a, b, c. 1862.

- Tryblionella tryblio sensu Lange-Bertalot et al. (2017: 600 , pl. 105, fig. 14).

- Nitzschia tryblionella sensu Hantzsch in Rabenhorst, Alg. Sachs. No. 984. 1860.

- Nitzschia tryblionella p.p. sensu Krammer & Lange-Bertalot (1988: 37, pl. 27, fig. 1, 2).

- Nitzschia tryblionella sensu Hofmann et al. (2013: 466 , pl. 103, fig. 14).

Grunow (1862) described and depicted Tryblionella hantzschiana explicitly as a new taxon based on Hantzsch’s concept of Nitzschia tryblionella Hantzsch , published in Rabenhorst (1848–1860). Grunow‘s description reads: “Gross, Schalen lanzettlich Streifen über die ganze Schale gehend, 16–18 in 0.001. (Kielpunkte in gleicher Entfernung) angedeutet. Im süssen Wasser.” [88.8–98.8 μm length, 19.5–20.0 μm breadth, length/breadth ratio 4.55–4.94, fibulae 8–9 in 10 μm; data taken from the figures published in Grunow (1862) which are reproduced here as Figs 1–3 ].

Type localities:—(syntypes) In den warmen Bädern Ofens [thermal springs at „Ofen“, former Austro-Hungarian Empire], In Ufertümpeln des Neusiedler Sees [shoreline pools of Lake Neusiedel, AUSTRIA], Tümpel mit warmem Wasser am Raaber Bahnhofe bei Wien [warm pool near the railway station „Raaber Bahnhof“, AUSTRIA], Falaise, leg. Brébisson [Falaise, Calvados, Normandy region in northwestern FRANCE], in Bächen um Dresden, leg. Hantzsch [in creeks near Dresden, Saxony, GERMANY].

Taxonomic comment: When Hantzsch in Rabenhorst (1860) studied Nitzschia species, he gave Tryblionella gracilis W.Sm., Syn. Brit. Diat. 1853 a new name within Nitzschia as Nitzschia tryblionella Hantzsch to avoid a later homonym of Nitzschia gracilis Hantzsch in Rabenhorst, Alg. Sachs. Dec. 95/96: no. 946. 1860. Hantzsch’s taxonomic concept of Tryblionella gracilis differed from Smith’s original species. From the nomenclatural point of view Hantzsch’s taxonomic concept was just a misidentification which has no standing, nevertheless this concept became important for Central European floras and monitoring, for instance as DV-Nr. 6119 in Mauch et al. (2003).

The first person to recognize the difference between Smith’s species and Hantzsch’s taxonomic concept was Grunow (1862) who described Tryblionella hantzschiana Grunow as a new species on the basis of Hantzsch’s and his own observations (see also Figure 1–3 ). Rabenhorst referred the respective German findings to Tryblionella gracilis Rabenhorst (1863) and later to Tryblionella hantzschiana Rabenhorst (1864 –1868). Current treatments of Tryblionella hantzschiana ( Krammer & Lange-Bertalot 1988, Hofmann et al. 2013, Lange-Bertalot et al. 2017) include literature data belonging to Tryblionella gracilis only. Verified data from Tryblionella hantzschiana populations from Central Europe indicates cells between 88.8–109 μm long, 19.5–29.0 μm broad, a length/breadth ratio of 3.75–4.94 and 5–9 fibulae in 10 μm. The variability of the taxon might be higher but records need to be checked carefully. The documentation by Lister (2016) sub Tryblionella gracilis is in accordance with Tryblionella hantzschiana but differs from Smith’s (1853) original documentation.

Tryblionella tryblio Cantonati et Lange-Bert. in Lange-Bertalot et al. (2017): 597, nom. inval.

≡ Nitzschia tryblionella Hantzsch in Rabenhorst, Alg. Sachs. No. 984. 1860.

≡ Tryblionella gracilis W.Sm., Syn. Brit. Diat. I : 35, pl. X: fig. 75a, b. 1853.

Nomenclatural comment: Tryblionella tryblio was the intended replacement name for Nitzschia tryblionella within the genus Tryblionella . In fact a valid name already existed; hence the new name is superfluous and has no standing (Art. 41.5, Art. 52.1, McNeill et al. 2012).

Taxonomic comment: Tryblionella gracilis W.Sm. as documented by Smith (1853) appears heterogeneous and includes cells of 54.5–67.0 μm length with a length/breadth ratio from 4.74 to 7.86. The maximum cell length of 190.5 μm (reported by Smith 1853) surely belongs to another taxon with a similar shape. Currently we suspect that Smith’s (1853) figures are unlikely to be conspecific, neither with each other nor with the Central European Tryblionella hantzschiana (see above).

Figures

FIGURES 1–3. Tryblionella hantzschiana Grunow reproduced from Grunow (1862: pl. XVIII: 29a, b, c), Original material (Scale bar: 10 μm), cited by Rabenhorst (1864–1868) and corresponding to pl. 27: fig. 1 in Krammer & Lange-Bertalot (1988), pl. 103, fig. 14 in Hofmann et al. (2013), and pl. 105, fig. 14 in Lange-Bertalot et al. (2017).