Eunotia praerupta Ehrenb., 1843: p. 414.

Bukhtiyarova, Lyudmila N., 2019, The genus Eunotia Ehrenb. (Bacillariophyta) in the Cheremsky Nature Reserve, Ukrainian Polissya, and refined terminology relevant to the raphe system morphology, PhytoKeys 128, pp. 1-31 : 13-14

Eunotia praerupta Ehrenb., 1843: p. 414. Fig. 31 (SEM)

Eunotia praerupta f. curta (Grunow) Mayer, 1917

Eunotia bidens var. praerupta (Ehrenb.) Aysel, 2005

Illustrations.

Krammer and Lange-Bertalot 1991: pl. 148/figs 1-3; Pavlov and Levkov 2013: p. 35, pl. 18/fig. 7 (SEM), pl. 19/figs 1-10.

Diagnosis.

Morphometric data: length 73 µm, width 20 µm; striae density c5, p8 in 10 µm. Pavlov and Levkov 2013: length 37-73 µm, width 13-17 µm; striae density c5-9, p8-12 in 10 µm.

Frustule bi-symmetric, bipolar, biraphid with mirror-symmetric, mantle-offset, brevisslit type of raphe. Valves dorsiventral, with strongly convex dorsal and weakly concave ventral margins, gradually narrowed to rostrate poles that are about perpendicular to the valve margins. Striae basal, uniserial, distant, irregularly spaced. Areolae small with round outer foramina. Raphe system consists of two short filiform slits on ventral valve mantle, distal ends of the slits finish on external valve surface on about 0.3 of pole width by small round pore-like outer connected with helictoglossae (see Pavlov and Levkov 2013: pl. 18/fig. 7); tr-fissures absent.

Ecology.

Freshwater epiphytic species.

Distribution.

Species was recorded in most European countries and on all continents except Antarctica (M. Gury in Guiry and Guiry 2019). In Ukraine. First record in the Cheremsky Nature Reserve, tract Obkopane, ditch, epiphyton on Sphagnum sp.

Comments.

No illustrations were published by the author of this species, which has led to a very wide species concept and uncertain taxonomy. In this paper the concept of Eunotia praerupta sensu stricto proposed in Krammer and Lange-Bertalot (1991: pl. 148/figs 1-3) has been followed.

Figures

Figures 28 - 35. Species of Eunotia Ehrenb. from the Cheremsky Nature Reserve. 28, 28 a, 29 Eunotia dorofeyukiae Lange-Bert. & Kulikovskiy 28 a arrow indicates pore outer on the raphe slit distal end 29 arrow indicates rimoportula at the venral corner of pole where raphe slit distal end finishes on the outer valve surface 30, 30 a Eunotia neocompacta S. Mayama 30 a arrow indicates rimoportula at the venral corner of pole, absence of a hyaline field indicates absence of terminal fissure 31 Eunotia praerupta Ehrenb. 32 Eunotia sp. 6. 33 Eunotia sp. 7. 34, 35 Eunotia tetraodon Ehrenb. Figs 28 - 31 SEM: 28, 28 a outside valve surface; 29 - 31 inside valve surface; 32 - 35 LM. Scale bars: 5 µm (28, 29, 30); 2 µm (28 a); 1 µm (30 a); 10 µm (31 - 34).