The ultrastructure and systematics of Schizocaryum dogieli, a ciliate endocommensal in Pacific echinoids

Schizocaryum dogieli Poljansky &Golikova, 1957 was isolated from several species of Pacific strongylocentrotid echinoids in the area of Friday Harbor, WA. The somatic kineties are composed of polykinetids of up to 15 kinetosomes of which only the right posterior one bears a postciliary ribbon at triplet 9, an anteriorly directed kinetodesmal fibril at triplets 6 and 7, and a transverse ribbon at triplets 4 and 5. The other kinetosomes are irregularly associated with this kinetosome by dense basal connectives. The oral ciliature consists of a series of primary transverse rows separated by cortical ridges and associated with numbers of irregularly arrayed, ciliated kinetosomes. The rightmost kinetosome of each primary transverse row apparently bears a postciliary ribbon. Schizocaryum dogieli is removed from the family Plagiopylidae and placed in a new, monotypic family, the Schizocaryidae Jankowski n.fam. This family has an uncertain position within the phylum Ciliophora.

Comparative ultrastructure and systematics of the Colpodida. An ultrastructural description of Colpoda maupasi Enriquez, 1908

Structural variation at different levels of biological organization is considered important to the systematics of ciliated protozoa. Analysis of the ultrastructural literature on ciliates led to the structural-conservatism hypothesis, which has been formulated to account for the variation of ultrastructural components, primarily microtubular, in the cortex of diverse ciliate genera. The hypothesis proposes that the conservation of structure through time is inversely related lo the level of biological organization. This study presents a light microscopic and ultrastructural description of Colpoda maupasi Enriquez, 1908. Comparison of C. maupasi with other species of the Colpodida supports the structural-conservatism hypothesis. With this hypothesis, several relational inconsistencies are demonstrated in the present scheme of classification of the ciliates.