Caloneis liber (Smith) Cleve

Division: Chromophyta
Class: Bacillariophyceae
Order: Bacillariales
Suborder: Bacillariineae
Family: Naviculaceae Kützing
Genus: Caloneis Cleve
Scientific name: Caloneis liber (Smith) Cleve

Cells solitary, free; valves linear, linear-lanceolate to lanceolate-rhombic, more or less convex; valve surface striate; striae crossed by one or more longitudinal lines.

Chromatophores: usually two (Hendey, 1964).

Synonym:
Navicula liber Smith

References:
Hendey, 1970: p. 151; Ricard, 1987: p. 243, Fig. 765; Witkowski et al., 2000:
p. 166, Pl. 152: 9.

Description:
Valves elongate to elongate-elliptic with rounded apices, 50-90 µm long,9-11 µm broad. Raphe slightly undulated, external central endings moderately distant, axial area narrow, central area small, circular. Transapical striae parallel, 18 in 10 µm, midway between raphe and valve margin crossed by longitudinal line (Witkowski et al., 2000).

Dimensions:
Cells length 75-96 µm; width 16-18 µm.

Distribution:
Mainly littoral cosmopolitan species, but is occasionally found in the plankton.

Sites of occurrence in RSA:
In Winter 2006 Cruise, this species occurred at different sites (refer sites map), usually in small numbers; maximum abundance (2.2*10^2 cells/l) was associated with northwestern part of the inner RSA off Saudi Arabia (St. 15). It has been previously reported from Kuwaiti shore (Hendey, 1970).