Family: Asterolampraceae Smith
Genus: Asteromphalus Ehrenberg
Scientific name: Asteromphalus flabellatus (Brébisson) Greville
Cells single, disk-shaped, with circular or slightly ovoid outline. Valves flat, with radial undulations. Areolated with a central smooth region and smooth radial rays running from the central smooth area to the margin. Rays are raised above plane of the valve more as they progress outward. One ray narrower than others. Girdle zone undulating, following the rays and depressions between them. Chromatophores numerous, often arranged in rays (Cupp, 1943).
Pavillard, 1925: p. 19, Fig. 27; Hustedt, 1930: p.498, Fig. 279; Allen and Cupp, 1935: p. 122, Fig.22; Hendey, 1970: p. 115; Simonsen, 1974: p. 25;Ricard, 1987: p. 151, Fig. 58; Hasle and Syvertsen,1997: p. 135, Pl. 24.
Central area slightly eccentric. Separating lines straight. Extension of the narrow ray inside the central area rectangular to club shaped. The remaining hyaline rays straight or slightly curved and narrow. Areolated sectors narrow and curved toward valve center. Longer diameter 40-60 µm, shorter diameter 24-50 µm; 16 areolae in 10 µm; 7-11 hyaline rays, central area 0.4-0.6
diameter (Hasle and Syvertsen, 1997).
Longer diameter 42-48 µm; shorter diameter 28-31 µm.
Sites of occurrence in RSA:
In Winter 2006 Cruise, this species occurred in small numbers at scattered sites (refer sites map); maximum abundance (65 cells/l) was associated with the central part of the inner RSA (St. 50). It has been previously reported from the inner RSA (Simonsen, 1974) and from Kuwaiti shore (Hendey, 1970) and coastal waters (Al-Kandari et al., 2009).