Bellerochea horologicalis von Stosch

Division: Chromophyta
Class: Bacillariophyceae
Order: Biddulphiales
Suborder: Biddulphiineae
Family: Lithodesmiaceae H. and M. Péragallo emend Simonsen
Genus: Bellerochea Van Heurck emend von Stosch
Scientific name: Bellerochea horologicalis von Stosch

Cells usually united to form chains so that the valves are more or less in contact over the whole surface, except for small foramina near the margins. Cells rectangular in girdle view, narrow. Valves bipolar, lanceolate or triangular, with concave undulating sides. Valve apices slightly produced; valve surface very weakly siliceous, with a central projection and a circlet of fine spinulae around the margin. Chromatophores numerous small spherical bodies scattered throughout the cell (Hendey, 1964).

References:
Ricard, 1987: p. 219, Figs. 545, 546; Hasle and Syvertsen, 1997: p. 229, Pl. 48.

Description:
Ribbons, curved in transapical plane or straight; cells biangular, intercellular space dumbbell shaped; costae partly continuous. Length of pervalvar axis 40-54 µm, apical axis 28-98 µm, transapical axis 25-32 µm; mantle costae 23-27 in 10 µm (Hasle and Syvertsen, 1997).

Dimensions:
Cells length 33-38 µm; width 20-22 µm.

Distribution:
Warm-water species.

Sites of occurrence in RSA:
In Winter 2006 Cruise, this species occurred at few scattered stations (refer sites map) in small numbers; maximum abundance (8.6*10^2 cells/l) was associated with the Iranian coast in the central part of the inner RSA (St. 20). It has been previously reported from Kuwaiti waters of the inner RSA (Al-Yamani et al., 2004; Al-Kandari et al., 2009).