Portrait

Description:

Portrait of Microthorax viridis (Penard,1922), a small nassophorean ciliate. The body is strongly dorsoventrally flattened. The right side is gently rounded and the left is straight. This genus has delicately ridged armor. The cytostome is in a notch in the left posterior body (seen here). The spheroid macronucleus is central. One or two contractile vacuoles are usually adjacent to the oral aperture. M. viridis has endosymbiotic algae (probably Chlorella). Collected from a eutrophic freshwater dredge pit near Idaho City, Idaho September 2003. DIC optics.