Pleurosigma strigosum Smith
Division: Chromophyta
Class: Bacillariophyceae
Order: Bacillariales
Suborder: Bacillariineae
Family: Naviculaceae Kützing
Genus: Pleurosigma Smith
Scientific name: Pleurosigma strigosum Smith
Species: strigosum
Synonym:
Pleurosigma angulatum v. strigosa Van Heurck
Reference:
Hendey, 1964: p. 246, Pl. XXXVI: 7.
Description:
Valves lanceolate, slightly sigmoid, with subobtuse apices. Raphe sigmoid, somewhat eccentric toward the ends; central area small, subcircular. Valve surface striate; striae oblique and transverse. Oblique striae are crossing each other at an angle of about 60º. Striae equidistant, 18-22 in 10 µm. Chromatophores two large plates lying against the valves. Lengt of valve 164-300 µm, breadth 32-36 µm (Hendey, 1964).
Dimensions:
Cells length 120-140 µm; width 28-33 µm.
Distribution:
Mainly littoral species, but is frequently found in the plankton.
Sites of occurrence in RSA:
In Winter 2006 Cruise, it was present in small numbers at two stations (refer sites map).