Eunotia neocompacta S. Mayama in Mayama and Kawashima 1998: p. 69.

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

Eunotia neocompacta S. Mayama in Mayama and Kawashima 1998: p. 69. Figs 30 , 30a (SEM)

Eunotia exigua var. compacta Hustedt, 1930: p. 176, fig. 225 [Basionym]

Eunotia compacta (Hustedt) S. Mayama, 1997

Eunotia neocompacta var. vixcompacta Lange-Bert. in Lange-Bertalot et al. 2011

Illustrations.

Grunow in Van Heurck 1881: pl. 34/fig. 8 - second exemplar; Krammer, Lange-Bertalot 1991: pl. 134/figs 32, 35-38 (both citations as Eunotia nymanniana Grunow). Mayama 1997: p. 35, figs 22-25, 26-31 (SEM) (as E. compacta ). Lange-Bertalot et al. 2011: p. 173-174, pl. 123/figs 1, 2-16, 25-28, 32-34 (SEM); Bąk et al. 2012: pl. 19/1, 2 exemplars from left to right; Genkal and Komulaynen 2015: fig. 2 л; Rivera-Rondón and Catalan 2017: pl. 33/figs 15-19 (all citations as E. neocompacta var. vixcompacta ). Kulikovskiy et al. 2016: p. 126, pl. 25/figs 7-11; Mimura and Ohtsuka 2016: fig. 34; Bahls et al. 2018: pl. 83/figs 8, 9.

Diagnosis.

Morphometric data: length 27 µm, width 3.5 µm, striae density 20 in 10 µm.

Mayama 1997: length 18-57 µm, width 3.5-5 µm, striae density 20-22 in 10 µm.

Frustule bi-symmetric, bipolar, biraphid with mirror-symmetric, mantle-offset, brevisslit type of raphe. Valves dorsiventral, weakly arcuate, uniform in width, with truncated poles strongly deflected to dorsal side. Striae basal, uniserial, distant, evenly spaced (Fig. 30a ). Areolae small with round outer foramina. Raphe system consists of two short filiform slits which are straight on ventral valve mantle and widely rounded at valve poles, distal ends of the slits finish on external valve surface on the middle of the poles by small round pores connected with helictoglossae of average size (Fig. 30a ; see Mayama 1997: figs 28, 29); central raphe pores on outer valve surface are funnel-like (see Mayama 1997: fig. 31); tr-fissures absent (see Mayama 1997: fig. 31).

Ecology.

Freshwater epiphytic species.

Distribution.

EUROPE: Georgia, Ireland, Netherlands, Poland, Romania, Ukraine (M. Gury in Guiry and Guiry 2019); France, Pyrenees, Lake Monges ( Rivera-Rondón and Catalan 2017); Russia ( Genkal and Komulaynen 2015: as E. neocompacta var. vixcompacta ). N. AMERICA: USA, Alaska, Atlantic Islands (M. Gury in Guiry and Guiry 2019); Canada ( Bahls et al. 2018). ASIA: Japan ( Mimura and Ohtsuka 2016); Russia ( Kulikovskiy et al. 2016); Russia, Bering Island (M. Gury in Guiry and Guiry 2019). In Ukraine. First record in the Cheremsky Nature Reserve, tract Obkopane, Lake Redychi, epiphyton on Sphagnum sp.

Comments.

In some publications the illustrations of this species are not uniform in valve outline, therefore only those microphotos which correspond to the species concept in Mayama (1997) are cited in the present paper. For instance, the specimen in Bouchard et al. (2018: pl. 1/fig. 6) has arcuate valve and longer poles therefore does not match to E. neocompacta sensu stricto.

Based on its morphology, Eunotia neocompacta var. vixcompacta ( Lange-Bertalot et al. 2011) is conspecific with E. neocompacta , which has also been confirmed by other authors ( Kulikovskiy et al. 2016, Mimura and Ohtsuka 2016, Bahls et al. 2018).

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).