Devescovinid trichomonad with axostyle-based rotary motor ("Rubberneckia"): Taxonomic assignment as Caduceia versatilis sp nov.

An amitochondriate trichomonad cell of the family Devescovinidae (Class Par abasalia), helped demonstrate the fluid model of lipoprotein cell membranes [24]. This wood-ingesting symbiont in the hindgut of the dry wood-eating t ermite Cryptotermes cavifrons is informally known to cell biologists as "Ru bberneckia". As the microtubular axostyle complex generates force causing c lockwise movement of the entire anterior portion of the cell at the shear z one the protist displays "head" rotation. Studies by phase contrast and vid eomicroscopy of live cells, of whole mounts by scanning, and thin sections by transmission electron microscopy extend the observations of Tamm and Tam m [24-26] and Tamm [19-23]. Habitat, cell shape, size, nuclear features, pa rabasal apparatus and other morphological details permit the assignment of "Rubberneckia" to Kirby's cosmopolitan genus Caduceia. This large-sized dev escovinid has distinctive parabasal gyres, an axostylar rotary motor, and r egularly-associated nonflagellated, fusiform and flagellated rod epibiotic surface bacteria. In addition to regularly aligned epibionts intranuclear a nd endocytoplasmic bacteria are abundant and hydrogenosomes are present. "R ubberneckia" is compared here to the other seven species of Caduceia. Since it is clearly sufficiently distinctive to warrant new species status, we n amed it C. versatilis.