Family: Hemiaulaceae Heiberg
Genus: Cerataulina H. Péragallo
Scientific name: Cerataulina bicornis (Ehrenberg) Hasle ex Hasle et Sims
Cells cylindrical, usually in chains. Valves slightly arched, with two blunt projections or processes near their margin; attached to adjacent cell by means of a fine, small, curved, hairlike process which fits into the valve of the adjacent cell. Intercalary bands numerous,annular. Chromatophores numerous, small. Nucleus against the cell wall. Cell wall soft and weakly siliceous, collapsing when dried. Sculpturing very delicate (Cupp, 1943).
Syringidium bicorne Ehrenberg; Cerataulina compacta Ostenfeld;
Cerataulina daemon (Greville) Hasle
Hasle and Syvertsen, 1997: p. 171, Pl. 32.
Species are characterized by broad wing-like extensions of the elevations fitting into V-shaped deep furrows on mantle of adjacent valve. Labiate process marginal; areola array irregular. Diameter 5-75 µm, pervalvar axis 87-200 µ; 18-30 valve striae in 10 µm (Hasle and Syvertsen, 1997).
Cells length 65-95 µm; diameter 22-37 µm.
Coastal warm-water species.
Sites of occurrence in RSA:
In Winter 2006 Cruise, this species occurred at two sites (refer sites map), usually in small numbers; maximum abundance (1.7*10^3cells/l) was associated with the Sea of Oman (St.22a). It has been previously reported from Kuwaiti waters of the inner RSA (Al-Kandari et