Family: Rhizosoleniaceae De Toni
Genus: Neocalyptrella Hernández-Becerril et Meave
Scientific name: Neocalyptrella robusta (Norman) Hernández-Becerril et Meave
This genus has one species. Genus description as for the species.
Rhizosolenia robusta Norman
Pavillard, 1925: p. 29, Fig. 43 (as Rhizosolenia robusta); Hustedt, 1930: p. 581, Fig. 330 (as Rhizosolenia robusta); Allen and Cupp, 1935: p. 126,Fig. 31 (as Rhizosolenia robusta); Cupp, 1943: p. 85,Fig. 46 (as Rhizosolenia robusta); Crosby and Wood,
1958: p. 523, Pl. 39: 75 (as Rhizosolenia robusta);Hendey, 1964: p. 148, Pl. II: 5 (as Rhizosolenia robusta); Simonsen, 1974: p. 29 (as Rhizosolenia robusta); Ricard, 1987: p. 171, Figs. 212-214 (as Rhizosolenia robusta); Throndsen et al., 2007: p. 157.
Cells cylindrical with deeply convex or conical curved valves; 48-130 µm in diameter, up to 0.5 mm or even 1 mm long. Valvar plane elliptical. Cells either crescent-shaped or S-shaped. Usually living singly or in short chains. Intercalary bands robust, numerous, typically collarshaped. Calyptrae with distinct longitudinal lines (growth sectors) and eccentric process with a fine, bristlelike point and suddenly dilated, hollow base. Cell wall thin, but more strongly siliceous than in most of the other species of this genus. Membrane delicately punctated,puncta in three-line, self-crossing system (quincunx). Puncta on valve 19-20 in 10 µm; on intercalary bands 24-26 in 10 µm. Chromatophores numerous, lying along the wall. Nucleus near the wall (Cupp, 1943).
Cells length 420-580 µm; diameter 100-110 µm.
Oceanic species; widely distributed, especially in warm water.
Sites of occurrence in RSA:
In Winter 2006 Cruise, this species occurred occasionally in very small numbers at different sites (refer sites map). I t has been previously reported (as Rhizosolenia robusta) from the inner RSA (Simonsen, 1974) and from Kuwaiti waters (Al-Yamani et al., 2004; Al-Kandari et al., 2009 – as Rhizosolenia robusta).