portrait

Description :

Portrait of the small Enchelyid ciliate, Pithothorax rotundus (Kahl, 1927). The body is cylindrical, bluntly tapered anteriorly and rounded posteriorly. The right side is gently convex, the left side more straight giving the anterior portion the appearance of being bent slightly to the left. The pellicle is rigid with longitudinal ridges much less prominent than those seen in P. processus. The ridges converge around the anterior apical cytostome. The cytopharynx is supported by delicate trichites. In this image a cluster of discharged extrusomes is seen to the viewer's right. The somatic cilia are reduced to a few kineties in the anterior and posterior quarter of the cell. The macronucleus is central and the single contractile vacuole posterior. Pithothorax is a sapropelic genus usually found in hypoxic bottom sediments with decomposing organic matter. Collected from bottom sediments of freshwater aquaculture tank near Boise, Idaho January 2004. DIC optics.