Cambodge

Cambodia (kh)

Anlong Reang district

Pursat province

Tonle Sap Lake

 s.c.

12° 38' 24'' N ; 104° 8' 9.6'' E

12.64 ; 104.136

Cells solitary. Frustules cylindrical, straight with extended pervalvar axis. Valves symmetrical with a conical base and very long hair-like extensions. Connective bands of the cingulum hardly visible in light microscopy. Valve dimensions (n = 15): valve length (including extensions) 196–370 μm, width 4.0–7.0 μm. Valve margin devoid of any pores, forming a well-defined rim. Valve face ornamented with fine, rounded to elliptic, areolae approximately aligned with the apical axis. Variable numbers (1–5 per valve face) of large, rounded, elliptic to elongated perforations mostly associated with the base of the process (extension) and more rarely with the valve margin. Irregular thin layer of silica covers the valve face and closes the external areola openings, but not the larger perforations. Perforations nevertheless hardly visible in light microscopy. Valve (calyptra + seta) in the shape of a mediaeval lance, centric and slightly curved, 60–102 μm long. Four tooth-like projections present at the apex of the calyptra, two on the sides and two others in front of the calyptra-seta connection (Figs 42–43). Calyptra elongated by a seta ending with a ligula (Fig. 41). Valve length: 75–120 μm. Cingulum with multiple semi-circular half-band copulae (4–6 in 10 μm), scalelike, forming a zigzag imbrication. Copulae ornamented with transapical rows of elliptical pores (40–44 per 5μm)

Standing water of flood plain and flooded forest