Portrait (left side)

Description:

Portrait (left side) of the haptorid ciliate, Perispira ovum (Stein, 1859). The cell body is cylindrical to ovoid. The anterior end is slightly truncate. An unciliated cortical ridge makes a complete right-hand spiral the length of the body. The slit-like cytostome, supported by fine trichites, is located at the anterior end of the cortical ridge. The uniform longitudinal somatic kineties spiral slightly. Densely packed food vacuoles and highly refractile cytoplasmic crystals often obscure the ellipsoid macronucleus. There is a single large terminal contractile vacuole posteriorly. Swims slowly. Collected from anoxic bottom sediments of slow flowing freshwater stream near Boise, Idaho December 2004. DIC optics