Sellaphora balashovae Andreeva, Kulikovskiy & Kociolek, 2018

Andreeva, Svetlana, Kociolek, John P., Maltsev, Evgeniy, Dorofeyuk, Nadezhda, Kezlya, Elena, Shkurina, Natalia, Kuznetsova, Irina, Gusev, Evgeniy & Kulikovskiy, Maxim, 2018, Sellaphora balashovae (Bacillariophyta), a new species from Siberian mountain Lake Frolikha (Baikal region), Russia, Phytotaxa 371 (2), pp. 73-83 : 76

Sellaphora balashovae Andreeva, Kulikovskiy & Kociolek sp. nov. Figs 1–14 (LM), 15–22 (SEM)

Description: Valve outline is elliptic with sub-capitate apices ( Figs 2–16 , 18–20 ). Valve dimensions (n=33): length 11–14 μm, breadth 4 μm. Raphe is straight, filiform and barely noticeable under LM ( Figs 2–14 ). A narrow, linear and externally conspicuous sternum represents an axial area ( Figs 15, 16 ). Axial area widens towards the central area. External proximal raphe ends are slightly drop-like and deflected to the same side, but to the opposite direction than the terminal ends ( Fig. 16 ). Terminal raphe fissures are externally hooked and unilaterally deflected, reaching the valve mantle at the apex ( Fig. 15 ). Internally, axial area is represented by the slightly elevated sternum, proximal ends of the raphe are slit-like and deflected to the one direction ( Figs 18–20 ). Distal raphe ends are as simple helictoglossae, situated on a straight line with the raphe, not following the external terminal raphe ends ( Fig. 18–20, 22 ). Central area is bowtie-shaped, bordered by alternating short and long striae ( Figs 2–17 ). Striae are barely visible under LM ( Figs 2–14 ). Striae are uniseriate, strongly radiate in mid-valve, becoming parallel to slightly convergent near the valve apices, 30 in 10 μm ( Figs 15–16 , 18–20 ). Striae are composed of areolae with irregularly rounded openings, covered by hymenes inside, 60 areolae in 10 μm ( Fig. 18–21 ). Striae continue uninterrupted with an areola on the valve mantle ( Figs 15 ). Chloroplast is a single H-shaped plastid ( Fig. 1 ).

Holotype: slide 75/B385, (holotype here designated see Fig. 4 ) in collection of Maxim Kulikovskiy ( Institute of Plant Physiology Russian Academy of Sciences). (leg. M. Kulikovskiy, E.S. Gusev)

Type locality: Lake Frolikha, Russia. N55°26.254 E110°01.268, 26.07.2012.

Etymology: species dedicated to Dr. Natalia Borisovna Balashova, algologist from St-Petersburg State University, mentor of the first author of this manuscript.

Figures

FIGURES 1–17. Sellaphora balashovae sp. nov. Fig. 1: Live cell with chloroplast structure. Figs 2–14: Valve view. Fig. 2: Valve from samples collected in the Lake Frolikha. Figs 15–16: External valve views, note an axial area represented by sternum. Fig. 17: External view of valve central part. (1–14: LM; 15–17: SEM). Scale bar for LM: 10 μm.

FIGURES 18–22. Sellaphora balashovae sp. nov. Figs 18–20: Internal valve view note small helictoglossae, uniseriate striae. Fig. 21. Internal view of valve central part, note bowtie central area. Fig. 22. Internal view of valve end, note helictoglossa and raphe slit.