portrait

Description:

Gyrodinium oblongum cells are oblong from the ventral side, dorso-ventrally flattened posteriorly, length 17 - 25 microns, width 6-10 microns. The epicone and hypocone are approximately equal in size. Cingulum displaced approximately 1/4 - 1/3 of cell length. The sulcus initially narrow but widens at the posterior end . Apical groove not present. Nucleus in the hypocone, approximately 5 microns diameter . Chloroplast single, yellow-brown, forms thin longitudinal strands towards the anterior and posterior ends. Obvious pyrenoid present, 3 - 4 microns diameter, in the centre of the cell.