Porosira sp

Division: Chromophyta
Class: Bacillariophyceae
Order: Biddulphiales
Suborder: Coscinodiscineae
Family: Thalassiosiraceae Lebour
Genus: Porosira Jørgensen
Scientific name: Porosira sp.

Cells usually united by means of a thick mucous rope or pad to form chains. Cells rectangular, with rounded corners, and furnished with spines. Valve surface very finely areolata. Girdle composed of several bands. Chromatophores numerous, rounded or irregular plates (Hendey, 1964).

Description:
Valve circular; slightly convex. Valve surface furnished with irregularly scattered pores. Numerous chloroplasts as irregular plates. Only solitary cells were observed in preserved material.

Dimensions:
Valve diameter 39-43 µm.

Sites of occurrence in RSA:
In Winter 2006 Cruise, this species was observed at few sites (refer sites map) in low abundance and occurred in the northwestern part of the inner RSA and within the Strait of Hormuz area.