portrait

Description:

Pleurosigma (ploo-row-sig-ma) and Gyrosigma are two rather similar genera of sigmoid-shaped pennate diatoms found in intertidal sediments, salt marshes and so on. The nucleus is located at the centre of the cell. The plastids contain chlorophylls a and c which gives the yellowy-brown colour. . Pleuosigma is distinguished in part by the angled pattern of marks on the valve of the frustule. Differential interference contrast.