Eunotia sinensis 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 : 244-246

Eunotia sinensis Q. Liu, S. L. Xie & Kociolek sp. nov. (LM: Figs 18–27, SEM: Figs 28–33)

Description: Valves biundulate on the dorsal margin, slightly concave on the ventral margin (Figs 18–27). Apices produced, bluntly rounded. Length 18–30 µm, breadth 6.5–8.0 µm, as measured at the center of the valve, 7–9 µm at the broadest distance. Striae indistinctly-punctate, radiate extending across the valve face, 10–14 / 10 µm, infrequently the dorsal margin having intercalated shortened striae. Striae interrupted near the valve face:mantle junction. Distal raphe ends curve onto the valve face extending only a short distance onto the face.

In the SEM, the valve exterior has striae that are composed of round areolae with external occlusions (figs 28–30). Near the raphe slit on the valve face there are several openings larger than the areolae that are without occlusions ( Figs 29 30 ). Striae are interrupted at the valve face:mantle junction. Striae are separated by narrow ribs ( Fig. 29 ). Internally, the striae appear as narrow, continuous slits (Figs 31–33). The raphe terminates at each apex in a helictoglossa (Figs 32, 33). At the apex there appears a small hollow area; no rimoportulae are evident. There is a narrow pseudoseptum on the valve (Figs 31–33).

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 slides YN201904033-2 deposited in the Kociolek Collection at the University of Colorado ( COLO) .

Etymology: Named for its occurrence in China.

Present in samples YN201904033, YN201904055.

Figures

PLATE 4. Eunotia sinensis Q. Liu, S. L. Xie & Kociolek, sp. nov. Figures 28–33. Scanning electron microscope images. Figures 28–30, external views. Fig. 28. Whole valve showing valve outline and distal raphe ends curing ca. ¼ of the way from the ventral margin towards dorsal margin. Figs 29, 30. Valve apices, with distal raphe end dilated slightly and curved onto the valve face. Areolae are occluded externally. Figures 31–33, internal views. Fig. 31. Whole valve, with pseudosepta present at each apex. Figs 32, 33, valve apices. Striae appear to be in continuous vertically-oriented troughs. Helictoglossa is short. The rimoportula is sessile, small.