portrait

Description:

Optical section through Metopus striatus (synonyms include M. bacillatus, M. gibbus, M. pullus and M. acuminatus among others), a colorless metopid ciliate. The body is broadly domed anteriorly. The posterior end is bluntly tapered or may terminate in a short finger-like process. The oblique peristome with its adoral zone of membranelles terminates at the oral aperture in the posterior 1/3 of the body. The large spherical macronucleus is located in the midbody. There is one adjacent micronucleus. The sparse somatic kineties are longitudinal coursing to the left around the anterior dome. There is a longer tuft of caudal cilia. The anterior refractile granules typical of metopids are much less conspicuous in this species. There is a prominent layer of subcortical extrusomes. A single contractile vacuole is located posteriorly. Collected from polysaprobic freshwater pond near Boise, Idaho September 2003. DIC optics.