Achnanthidium barlasii C.N.Solak, Wojtal, S.Blanco, Peszek & M.Rybak sp. nov.

Figs 2, 3, 4

Type.

TURKEY • Lake Salda; 37°33 ’37.88” N, 29°43 ’1.94” E; 1316 m a.s.l.; 14 Oct. 2017; Cüneyt Nadir Solak; holotype: slide n° 27295, valves illustrated here in Fig. 2E & V: deposited in the collection of Andrzej Witkowski at the University of Szczecin, Poland; isotype: slide n° TR _ BRD_ Salda Lake _EPF_3_ Oct2017: deposited at Kütahya Dumlupınar University, Turkey .

Description.

Valves linear to lanceolate, with parallel margins. Apices protracted (Fig. 2). Valve dimensions (n = 75): valve length 12.0-21.5 µm, valve width 2-3 µm (Table 1). Raphe valve (Figs 2A, C-S & 3A-H) linear with parallel margins. Axial area linear, gradually widening (Fig. 3A). Central area inconspicuous, delimited by 1-3 more distantly spaced striae composed of three, rounded areolae (Fig. 3B, F). Raphe straight, expanding at both central endings and terminal raphe fissures. Central raphe endings straight, terminal raphe fissures short (Fig. 2B-D). Transapical striae arched, strongly radiate throughout entire valve, more densely spaced near apices. Striae composed of 3 (1-2 at apices) rounded to rectangular areolae (Fig. 2B-D). Internally, central raphe endings terminating on a raised central nodule, weakly deflected in opposite directions (Fig. 2E-F). Rapheless valve (Figs 2T -AJ & 4A-H) lanceolate with convex margins. Central area absent (Fig. 3A, B, F). Transapical striae radiate and evenly spaced throughout the entire valve, 27-30 in 10 µm . Striae composed of 4 (2-3 at the apices) rounded areolae (Fig. 3B-D).

Etymology.

The species is named after our colleague Prof. Dr Murat Barlas, a hydrobiologist specialised in freshwater ecology in Turkey.