Description of Gigartacon fragilis:
Cell solitary, 6 x 4.6 microns, with two flagella. The long flagellum (about 10 microns) is naked, whereas the short flagellum (about 6 microns) is covered by minute oval scales (length: 0.20-0.28 microns; width: 0.16-0.21 microns) with a conspicuous scale rim. Body scales of one type cover the entire cell body. The triangular base plate with rounded corners (edge: 0.41-0.52 microns) supports a little developed superstructure consisting of symmetrically arranged branched rods of material that terminate in a large central projection and short projections along the adjoining strands of material.