Pseudosolenia calcar-avis (M. Schultze ) Sundström

Division: Chromophyta
Class: Bacillariophyceae
Order: Biddulphiales
Suborder: Rhizosoleniineae
Family: Rhizosoleniaceae De Toni
Genus: Pseudosolenia Sundström
Scientific name: Pseudosolenia calcar-avis (M. Schultze ) Sundström

This genus has one species. Genus description as for the species.

Synonym:
Rhizosolenia calcar avis M. Schultze

References:
Pavillard, 1925: p. 34, Fig. 52 (as Rhizosolenia calcar avis); Hustedt,1930: p. 593, Fig. 339 (as Rhizosolenia calcar avis); Allen and Cupp,1935: p. 129, Fig. 41 (as Rhizosolenia calcar-avis); Cupp, 1943: p. 90,Fig. 51 (as Rhizosolenia calcar avis); Crosby and Wood, 1958: p. 521, Pl.38: 65 (as Rhizosolenia calcar avis); Hendey, 1964: p. 151, Pl. IV: 3 (as Rhizosolenia calcar-avis); Hendey, 1970: p. 121 (as Rhizosolenia calcaravis); Simonsen, 1974: p. 28 (as Rhizosolenia calcar-avis); Throndsen et al., 2007: p. 158.

Description:
Cells rod-shaped cylindrical; the valves, not oblique, more regularly conical, curved at the apex. Cells 6-53 µm in diameter, up to nearly 1 mm in length. Intercalary bands scalelike, rhombic, in small individuals in two dorsiventral rows, in the widest forms, sometimes up to eight or more rows. Imbrication lines difficult to see. Process strong, gradually diminishing in size from the base to the point, curved like a claw. No wings on process. Cell wall thin and weakly siliceous; very delicately punctated. Puncta on valve 22-24 in 10 µm; on intercalary bands 20-23 in 10 µm. Chromatophores small, numerous (Cupp, 1943).

Dimensions:
Cells length 450-640 µm; diameter 35-48 µm.

Distribution:
Oceanic, warm-water species, subtropical to tropical.

Sites of occurrence in RSA:
In Winter 2006 Cruise, this species occurred at few sites (refer sites map) and in very small numbers. Species have been previously reported (as Rhizosolenia calcar-avis) from the inner RSA (Simonsen, 1974) and from Kuwaiti shore (Hendey, 1970) and coastal waters (AlYamani et al., 2004; Al-Kandari et al., 2009).