Family: Chaetocerotaceae Ralfs in Pritchard
Genus: Chaetoceros Ehrenberg
Scientific name: Chaetoceros denticulatus Lauder
Chaetoceros denticulatus f. angusta Hustedt; Chaetoceros denticulatus f. lata Hustedt;Chaetoceros nanodenticulatus Okamura.
Allen and Cupp, 1935: p. 134, Fig. 53; Crosby and Wood, 1958: p. 516, Pl. 37: 45;Simonsen, 1974: p. 31 .
Cells in straight chains, ends different;apertures very small, central; setae arising close to valve center, at first almost parallel with chain axis, then with an elbow, turning at right angles, with distinct tooth on lower setae; setae with spines; chromatophores numerous. Width 25-30 µm (Crosby and Wood, 1958).
Apical axis 28-33 µm; pervalvar axis 20-22 µm.
Typical species in tropical areas of the Indian Ocean with neritic preference.
Sites of occurrence in RSA:
In Winter 2006 Cruise, this species was frequently observed at various sites (refer sites map),often in large numbers; maximum abundance (3.8*10^3 cells/l) was associated with the Iranian coast in the central part of the inner RSA (St. 27). Species has been previously reported from the inner RSA (Simonsen, 1974) and from Kuwaiti waters (Al-Yamani et al., 2004; AlKandari et al., 2009).