Eunotia obtusisaculea Q. Liu, S. L. Xie & Kociolek

Liu, Qi, Liu, Enhui, You, Qingmin, Wang, Qinghua, Kociolek, John Patrick & Xie, Shulian, 2024, New and Interesting Diatoms from the Shiwan Wetwalls, Yunnan Province, China. III. Valve ultrastructure of four new species of Eunotia (Bacillariophyceae: Eunotiales), Phytotaxa 642 (4), pp. 242-254 : 247

Eunotia obtusisaculea Q. Liu, S. L. Xie & Kociolek sp. nov. (LM: Figs 34–42, SEM: Figs 43–50)

Description: In valve view, cells asymmetrical to the apical axis, with dorsal margin convex, ventral margin concave, with ends distinctly produced, rostrate appearing slightly deflected to the dorsal margin (Figs 34–42). Length 36–56 µm, breadth 7–9 µm. Striae radiate, distinctly punctate with individual areolae round, becoming parallel at the poles. Striae number 9–10 / 10 µm in the center, 15–19 / 10 µm at the apices. Dorsal margins appear to be bordered by a row of small spines.

In girdle view, striae extend onto both the dorsal and ventral margins. On the ventral margin the raphe branches are short, deflected towards the mantle. Striae denser on the mantle side of the raphe as compared to the striae closer to the valve face. A small spine is present at the apex of each valve.

In the SEM, the valve exterior has the dorsal margin with blunt spines (Figs 43–45). Uniseriate striae, composed of areolae with external occlusions, appear to be located in narrow troughs, separated by thick ribs (Figs 43, 45). The raphe is sigmoid, extending onto the valve face near the terminus of the valve. The proximal and distal ends are dilated slightly (Figs 44, 46). The girdle bands are numerous, the thickened valvocopula has 3–4 rows of porelli while the other cingular elements possess a single row of porelli (Figs 44, 46). Internally, striae appear to occur in trough-like opening s that extend across the valve face (figs 47–50). The distal raphe end terminates in a helictoglossa (Figs 47, 48, 50). A small pseudoseptum is present at the apices (Figs 47, 48, 50).

Type: CHINA. Yunnan Province, Shiwan wet wall. Holotype Preparation Slide No. YN201904033- 1 in the Freshwater Algal Herbarium of Shanxi University ( SXU), Taiyuan, China. Isotype slide YN201904033-2 deposited in the Kociolek Collection at the University of Colorado ( COLO) .

Etymology: Named for the blunt spines on the dorsal margin seen in this species.

Present in samples YN201904033 and YN201904055.