Gliwiczia vixcalcar Kulikovskiy, Lange-Bertalot & Witkowski, 2013

Kulikovskiy, Maxim, Lange-Bertalot, Horst & Witkowski, Andrzej, 2013, Gliwiczia gen. nov. a new monoraphid diatom genus from Lake Baikal with a description of four species new for science, Phytotaxa 109 (1), pp. 1-16 : 10-11

Gliwiczia vixcalcar Kulikovskiy, Lange-Bertalot & Witkowski sp. nov. Figs 89–107

Frustules with a horse shoe-like internal cavum at both raphid and rapheless valve as characteristic of the genus. Valves broadly elliptical, with broadly rounded ends. Length 10–18.5 µm, breadth 6.5–10 µm.

LM, raphe valve ( Figs 102–103 ): Raphe filiform, straight with expanded external central ends and distal ends that appear very slightly deflected to opposite sides (as in closely related taxa). Axial area narrow, linear. Central area forming a ca. 1 µ m broad stauros which is obscured by the internal cavum extending to approximately 1/4 of the valve width, unilaterally. Striae radiate throughout, ca. 25 in 10 µm.

LM, rapheless valve ( Figs 89–101 ): Axial area fusing with the proximal part of the central area rhombic to rhombic-lanceolate; central area continues in a ca. 1 µm broad stauros unilaterally, whereas the cavum on the opposite side extends from the margin to the central area. Striae 21–24 in 10 µm, appearing clearly punctate, areolae ca. 25 in 10 µm.

SEM, raphless valve, internal view ( Figs 104–106 ): Sternum and stauros, unilaterally with adjacent cavum, form a prominent relief. Raphe vestiges are present. Areola occlusions are in a state of moderate corrosion. On the valve mantle a row of areolae is somewhat set off from the areolae of the valve face.

SEM, raphe valve, internal view ( Fig. 107 ): Central raphe ends deflected clearly to opposite sides. The stauros together with the raphe sternum is strongly elevated above the internal valve surface. Cavum present extended from the centre nodule to the valve margin. Areolae uniseriate, small, approximately circular.

Type: slide no. 15645m (holotypus here designated see Fig. 95 ) in collection Maxim Kulikovskiy, I.D. Papanin Institute for Biology of Inland Waters , Russian Academy of Sciences ( IBIW) 20.07.1965, leg. A.P. Skabitschewsky.

Isotype: slide no. 15645a in collection Andrzej Witkowski, Institute of Marine Sciences, University of Szczecin (SZCZ).

Distribution: As yet known from the Lake Baikal.

Etymology: Latin vixcalcar means barely resembling calcar.

New taxonomic combination:

Gliwiczia calcar (Cleve) Kulikovskiy, Lange-Bertalot & Witkowski comb. nov.

Basionym: Achnanthes calcar Cleve 1891 in Cleve, The Diatoms of Finland. Actas Societas Pro Fauna et Flora Fennica 8(2): p. 51; pl. 3, figs. 8, 9(?).

Original drawings of this species from Cleve (1891) are illustrated in our Figs 117, 118. LM documentation

has been shown in Figs 114, 115.

Figures

FIGURES 89–107: Gliwiczia vixcalcar sp. nov. Figs 89-107: Figs 89–101: Valve view of rapheless valves. Fig. 89: arrow indicates presence of cavum in sternum valve. Figs 102, 103: Valve view of raphe valves. Fig. 103: arrow indicates presence of cavum in raphe valve. Figs 104–106: Internal valve view of rapheless valves. Fig. 106. Internal view of valve part, note the pore occlusion. Fig. 107: Internal view of raphe valve note presence of cavum (89–103: LM; 104–107: SEM). Scale bar: 10 µm.