Family: Rhizosoleniaceae De Toni
Genus: Guinardia H. Péragallo
Scientific name: Guinardia striata (H. Péragallo) Hasle
Rhizosolenia stolterfothii H. Péragallo; Eucampia striata Stolterfoth
Pavillard, 1925: p. 28, Fig. 42 (as Rhizosolenia stolterfothii); Hustedt, 1930: p. 579, Fig. 329 (as Rhizosolenia stolterfothii); Allen and Cupp, 1935: p. 125, Fig. 29 (as Rhizosolenia stolterfothii); Cupp, 1943: p. 84, Fig. 45 (as Rhizosolenia stolterfothii); Crosby and Wood,1958: p. 523, Pl. 39: 77 (as Rhizosolenis stolterfothii); Hendey, 1964: p. 148, Pl. IV: 5 (as
Rhizosolenia stolterfothii); Ricard, 1987: p. 171, Figs. 209-211 (as Rhizosolenis stolterfothii);Throndsen et al., 2007: p. 156.
Cells cylindrical; 6-30 µm in diameter. Uniformly curved along pervalvar axis. United in curved chains, often spiral. Valves flat, rounded at the edges. Strong spine on valve margin, fits into depression on adjacent cell. Intercalary bands collarlike, numerous. Imbrication lines not always distinct, but very clear sometimes. Cell wall weakly siliceous, without detectable structure. Chromatophores numerous, small, oval. Nucleus near wall (Cupp, 1943).
Cells length 65-78 µm; diameter, 28-33 µm.
Neritic, sometimes regarded as oceanic; very widespread species.
Sites of occurrence in RSA:
In Winter 2006 Cruise, it was one of the commonest species occurred at most of the sites in the RSA (refer sites map), encountered in 64.9% of the samples. Species were observed often in large numbers; maximum abundance (4.7*10^4cells/l) was associated with the Sea of Oman (St. 25a). Species have been previously reported (as Rhizosolenia stolterforthii) from Kuwaiti waters of the inner RSA (Al-Yamani et al., 2004; Al-Kandari et al., 2009).