black and white portrait

Description:

Cafeteria (cafeteria) marsupialis Larsen and Patterson, 1990. Cells are D-shaped and somewhat variable in shape. When attached the cells are 5 to 12 microns long (mostly about 7 to 8 microns) and 5 to 10 microns wide, When swimming the cells are up to 7 to 10 microns long and 3 to 5 microns wide. The cells attach to the substrate by the tip of the posterior flagellum, which lies in a deep ventral groove. The anterior flagellum is directed normal to the groove. The organism may feed on suspended bacteria, which are drawn towards the body by the activity of the anterior flagellum, entering along a curved channel at the posterior end of the ventral groove. The anterior flagellum of the attached cell is about 1.5 to 2 times the cell length and the posterior flagellum is slightly longer than the cell. A single nucleus with a rounded nucleolus lies just below the insertion of the flagella. The cell body may include many - sometimes large - food vacuoles. Undigested residues of food are egested by the fusion of old food vacuoles with the plasma membrane. Swimming cells are more rounded, with anterior flagellum directed to the anterior, recurrent flagellum trailing. It often occurs with Carpediemonas membranifera and C. bialata. More frequent in slightly anaerobic preparations.