Seminavis robusta D. B. Danielidis & D. G. Mann

Seminavis robusta Danielidis and Mann (2002): 440, figs. 39–53 — Wachnicka and Gaiser (2007); Kaleli et al. (2023).

Description

Valves strongly dorsiventral, frustules semi-lanceolate to rhombic-lanceolate, ends more or less obtusely rounded. Length 61.5 (34–104) µm, width 11.5 (6.5–13.5) µm. Margins convex dorsal with straight to slightly convex ventral margins. On dorsal side, axial area more expanded and rounded than on ventral side. Longitudinal raphe straight and displaced to ventral side. Externally, central raphe branches are slightly deflected ventrally and proximal raphe ends are deflected ventrally at apices. Dorsal striae slightly radiate in middle, 14 (12–20.7) in 10 µm and slightly denser 18 (15–18) in 10 µm at apices. Ventral striae at centre 14 (11–15) in 10 µm and at ends 17 (12–18). Middle striae are shorter than the others. Solitary cells.

Notes

This specimen from Retreat Cove conforms well with descriptions and data in literature. However, this specimen differs slightly from the description of Danielidis and Mann (2002) by having slightly radiate striae at the apices. iNaturalist ID: 263684273. Mol. data: ERS 27214058, ERS 27214059, ERS 27214060, ERS 27214061, ERS 27214062, ERS 27214063, ERS 27214064, ERS 27214065, ERS 27214066, ERS 27214067, ERS 27214068, ERS 27214069, ERS 27214070, ERS 21395352, ERS 21395356, ERS 21395359, ERS 21395369, ERS 21395365 (Fig. 31).