Family: Thalassionemataceae Round in Round et al.
Genus: Thalassionema Grunow
Scientific name: Thalassionema nitzschioides (Grunow) Mereschkowsky
Cells forming zigzag bands or star-shaped colonies; adjacent cells united to each other by small gelatinous cushions on one cell end, in girdle view, linear. Intercalary bands and septa are absent. Valves linear to narrow lancet-shaped; valves with numerous tiny spines on the margin placed at regular intervals; cell wall otherwise structureless. Chromatophores are more or less numerous small granules; only one species; pelagic, marine (Cupp, 1943).
Thalassiothrix nitzschioides (Grunow) Grunow; Synedra nitzschioides Grunow
Allen and Cupp, 1935: p. 153, Fig. 96 (as Thalassiothrix nitzschioides); Cupp, 1943: p. 182, Fig. 133; Hendey, 1964: p. 165; Hendey, 1970: p. 127; Simonsen, 1974: p. 37; Ricard, 1987: p. 223, Figs. 583- 586; Throndsen et al., 2007: p. 186.
Cells in girdle view narrow linear are, often slightly curved. Valves narrow linear with parallel sides and bluntrounded ends. Length 30-80 µm; width 2-3.5 µm. Marginal spines small, 10-12 in 10 µm. Valves otherwise without sculpturing. Cells united into star-shaped colonies or zigzag bands, frequently both types within a colony (Cupp, 1943).
Cells length 35-49 µm; width 3-4 µm.
Cosmopolitan, predominantly neritic species.
Sites of occurrence in RSA:
In Winter 2006 Cruise, this species occurred over most of the sampling sites (refer sites map),encountered in 82.7 % of the samples, often in large numbers; maximum abundance (3.1*10^4 cells/l) was associated with Kuwaiti waters in the northwestern part of the inner RSA (St. 1).It has been previously reported from the inner RSA (Simonsen, 1974) and from Kuwaiti shore (Hendey, 1970) and coastal waters (Al-Yamani et al., 2004; Al-Kandari et al., 2009).