Cymbella yerlii C.N.Solak, S.Blanco & N.Balkis-Ozdelice, 2021

Solak, Cüneyt Nadir, Balkis-Ozdelice, Neslihan, Yilmaz, Elif, Durmus, Turgay & Blanco, Saúl, 2021, Description of two new Cymbella (Bacillariophyta) species from Sakarbaşı spring, Turkey, Phytotaxa 484 (2), pp. 195-206 : 199-202

Cymbella yerlii C.N.Solak, S.Blanco & N.Balkis-Ozdelice , sp. nov. ( Figs 16–35 )

Description: Valves slightly to moderately dorsiventral, lanceolate, dorsal margin distinctly convex, ventral margin slightly tumid. Ends indistinctly protracted and rounded ( Table 2). Length 31.8–45.8 μm, breadth 7.4–9.0 μm, maximal length/breadth ratio of the normal cells 5.3. Axial area narrow, linear, central area absent. Raphe slightly ventrally displaced, lateral, becoming filiform near the distal and filiform to weakly reverse-lateral near the proximal ends [type “ e ” according to Krammer (2002: Fig. 67: 3)]. Striae parallel at the central area, becoming slightly radiate near the ends, finely punctate. A distinct isolated 1–2 stigmata are visible just at the end of the central stria on the ventral side. In the SEM, 1–2 slit-like stigma foramina. Parallel arranged pore field alveoli only on the valve end. The margins of the stigma alveoli are provided with teeth-like structures. Striae in the middle portion (dorsal and ventral) 9–10/10 μm, rising to 13–15/10 μm towards the ends, puncta 24–28/10 μm.

Type:— TURKEY, Sakarbaşı, Eskişehir ( GPS 39°21’10.04’’N, 31°03’33.24’’E), 872 m a.s.l., collector: Cüneyt Nadir Solak 24.11.2019. Holotype: slide number 27354 (holotype designated here on Fig. 1 ) in the collection of Andrzej Witkowski at the University of Szczecin.

Isotype:— Slide no. TR_ ESK _Sakarbası_ Nov2019 _EPF deposited at Kütahya Dumlupınar University ( Turkey) .

Etymology:— The species was dedicated to Prof. Dr. Sedat YERLİ who is a hydrobiologist in Turkey.

Differential diagnosis:— Cymbella parva (W. Smith) Kirchner in Cohn (1878: 188), C. perparva Krammer (2002: 37) and C. parviformis Krammer (2002: 38) and Cymbella tridentina H.Lange-Bertalot, M.Cantonati & A.Scalfi in Cantonati et al. (2010: 778) are similar taxa. Among them, C. parva is the most similar taxon in all related ones with similar outline. However, length/width ratio is higher in C. yerlii than the other taxa. In C. parviformis , striae density in dorsal and ventral sides are lower than C. yerlii . Regarding to the apices, the shape is non protracted and narrowly rounded in C. parva and C. parviformis while, indistindtly protracted and rounded in C. yerlii and C. parviformis .

Distribution:— Observed only in the type locality.

Ecology:— The water temperature ranged from 21.4–22.9 oC, pH was 7.8–7.9, dissolved oxygen (DO) was 5.2– 6.1 mg /L and electrolytic conductivity was 545–575 µS/ cm-1.

Associated diatom flora:— Cymbella cymbiformis (21.2%), Encyonopsis minuta Krammer & E.Reichardt in Krammer (1997: 95) (10.5%), Amphora pediculus (Kützing) Grunow [described as Cymbella pediculus Kützing (1844: 80) ] (5.3%), Navicula cryptotenella Lange-Bertalot in Krammer & Lange-Bertalot (1985: 62) (4.1%), Eunotia arcubus Nörpel & Lange-Bertalot in Lange-Bertalot (1993: 24) (3.8%), Nitzschia gracilis Hantzsch (1860: 40) (2.9%), Staurosira construens Ehrenberg (1843: 424) (2.5%), Pseudostaurosira brevistriata (Grunow) D.M. Williams & Round (1988: 276) (2.2%), Staurosirella pinnata (Ehrenberg) D.M. Williams & Round (1988: 274) (1.9%), unidentified species of Brachysira Kützing , Cocconeis Ehrenberg , Pseudostaurosira D.M.Williams & Round and Sellaphora Kützing were the most frequent taxa in the sample.

Figures

FIGURE 1. Map of study area

FIGURE 16–25. Light micrographs of Cymbella yerlii sp. nov. Scale bar = 10 µm.

FIGURE 26–31. SEM micrographs of Cymbella yerlii sp. nov. 26. External view of entire valve, 27. External view of central area showing striae composed of slit-like areolae, rounded-rectangular stigmata and the proximal raphe endings, 28, 29. External view of valve apex showing apical pore field, 30. Girdle view of entire valve, 31. Girdle view of valve apex showing apical pore field. Scale bars 10 µm (Figs 26, 30), 5 µm (Figs 27–29, 31).

FIGURE 32–35. SEM micrographs of Cymbella yerlii sp. nov. 32. Internal view of entire valve, 33. Internal view of valve central area showing internal stigma openings, 34, 35. Internal view of valve ends with dorsally curved, knob-like helictoglossae, apical pore field and uniseriate striae. Scale bars 10 µm (Fig. 32), 4 µm (Figs 33–35).