Kyaroikeus cetarius N. G., N. Sp.: A Parasitic Ciliate from the Respiratory Tract of Odonticete Cetacea

. Examination of mucus discharged from the blowholes of live odonticete Cetacea and material collected from nasal orifices of dead hosts routinely revealed infestations of a large spindle‐shaped ciliate. Kyaroikeus cetarius n. g., n. sp. These ciliates had a prominent posterior podite and were holotrichously ciliated except for a conspicuous bipolar stripe extending along the left margin of the cell. Most specimens were free‐swimming and moved slowly through freshly collected mucus, but some individuals were attached to host cells or cellular debris by a transparent thread secreted from the podite. The oral architecture of protargol‐impregnated K. cetarius consisted of one preoral and two circumoral kinetics set within a deep oral cavity continuous with an extensive, posteriorly directed cytopharynx. Somatic kineties were composed entirely of monokinetids and formed an expansive right ciliary field covering most of the cell surface, a reduced left ciliary field adjacent to the oral cavity, and a group of four kinetal fragments located mid‐ventrally within a shallow pocket. Subkinetal microtubules were associated with the kineties of the right and left fields, and the non‐ciliated stripe was underlain by a series of longitudinal fibers. The ciliate's large, heteromeric macronucleus was centrally positioned and clearly evident in living or stained specimens, while the ellipsoid micronucleus was located adjacent to the cytopharynx and often inconspicuous. K. cetarius has several morphological attributes typical of phyllopharyngian ciliates (e.g., adhesive organelle, heteromeric macronucleus, somatic kineties of monokinetids, subkinetal microtubules), and, except for its nearly holotrichous ciliation, most closely resembles dysteriine ciliates.