Navicula gololobovae Chudaev, 2016

Chudaev, Dmitry A. & Georgiev, Anton A., 2016, New taxa of Navicula sensu stricto (Bacillariophyta, Naviculaceae) from high-altitude lake in Tibet, China, Phytotaxa 243 (2), pp. 180-184 : 180-182

Navicula gololobovae Chudaev , sp. nov. ( Figs 1–15 )

Valves lanceolate with rostrate apices. Valve length 35.7–44.8 μm, valve breadth 7.1–8.0 μm. Axial area very narrow, linear, slightly widening near the central area. Central area relatively small, more or less rhomboidal in outline. Striae slightly arched, radiate, becoming convergent at ends. Valves with alternating short and long striae around central area. Striae density 14.3–15.6 in 10 μm.

Areolae lineolate, barely visible in light microscope, 32.1–35.5 in 10 μm. A single elongated areola lying more or less parallel to valve margin is located at each valve apex on the primary valve side. Raphe filiform, raphe-sternum not elevated over valve surface externally. Central external raphe endings hook-shaped and curved to the secondary valve side. In the center of the proximal part of each hook there is small knob-like thickening bridging sides of hook. Distal external raphe endings hook-shaped and curved to the secondary side of valve, with ends positioned on valve mantle. Central internal raphe endings straight. An accessory rib, lying at primary side of raphe-sternum internally, is slightly unilaterally widened in the center. Distal internal raphe endings with well-developed helictoglossae.

Type:— CHINA. Tibet Autonomous Region: nameless lake, 28° 37’ 16.88” N, 93° 13’ 43.04” E, periphyton on filamentous algae, Anomymous, 3 November 2006 (Holotype: MW! slide 313s1, diatom collection of the Department of Mycology and Algology, M. V. Lomonosov MSU, specimen here depicted in Fig. 4 . Isotype: IBIW! material 04108, collection of Maxim Kulikovskiy, Institute for Biology of Inland Waters RAS).

Etymology:— The species is dedicated to our colleague and friend Dr. Maria Gololobova. Distribution:— The taxon is thus far precisely known only from the type locality.

Figures

FIGURES 1–15. Navicula gololobovae, sp. nov. 1–11. Light microscopy, Fig. 4 illustrates the holotype specimen. 12–15. SEM. 12. Valve apex, external view. 13. Valve centre, external view. 14. Valve apex, internal view. 15. Valve centre, internal view. Scale bars: 10 μm (Figs 1–11), 1 μm (Figs 12–15).