Halostylodinium

Halostylodinium, a non-motile cell with a stalk, observed in marine muds and sandy sediments in the vicinity of Broome, Western Australia in September 2003.   This work was supported by the Australian Biological Resources Study.

Halostylodinium, a non-motile cell with a stalk, observed in marine muds and sandy sediments in the vicinity of Broome, Western Australia in September 2003. This image was taken using differential interference contrast optics.   This work was supported by the Australian Biological Resources Study.

Halostylodinium (hail-o-stile-o-din-ee-um) arenarium Horiguchi et Yoshizawa-Ebata 2000. The image shows a non-motile cell stage (temporary cyst). The cyst is connected to the surface of the slide with a stalk. The nucleus is in the anterior end of the cell. The cell contains yellow-brown plastids.

Halostylodinium arenarium motile cells are oval, dorso-ventrally rounded. Length 37 – 40 microns, width 27 microns. Non-motile cells are 38 - 40 microns in length, 30- 31 microns in width. Non-motile cells are attached to substrate by stalk from the apical pore. Stalk approximately 25 microns long, consisting of a thick tubule and a thinner tubule, with disc-shaped base. On the motile cell, cingulum begins approximately 0.5 of the cell length from the apex, displaced approximately one cingular width. Apical groove not present. Apical pore present, round, approximately 4 microns diameter. Sulcus initially narrow, then opening towards the antapex. Nucleus round, 12-14 microns diameter, in the posterior of the hypocone on the motile cell, but in the centre or anterior in the non-motile cell. Plastids long, orange-brown, radiating from the centre of the cell. Stigma not present. Occasionally red-orange bodies, possibly food particles, present.