Morphology, Morphogenesis, and Molecular Phylogeny of a New Soil Ciliate, Sterkiella multicirrata sp. nov. (Ciliophora, Hypotrichia) from China.

The morphology and morphogenesis of a new soil hypotrich ciliate, Sterkiella multicirrata sp. nov., was investigated using live observation and protargol staining. The new species is characterised by: body elliptical, 110-180 × 45-75 μm in vivo, an average of 35 adoral membranelles; usually 19 frontoventral-transverse cirri, consisting of three frontal, five frontoventral, one buccal, four postoral ventral, two pretransverse, and four transverse cirri; four macronuclear nodules, and 2-5 micronuclei. S. multicirrata sp. nov. differs from its congeners mainly in the number of frontoventral-transverse cirri and macronuclear nodules. Morphogenesis of the new species is similar to its congeners; the primary difference exists in the segmentation of the frontoventral-transverse cirral anlagen, which is usually generated in a 1:2:3:3:5:5 pattern. Based on the small subunit ribosomal DNA sequence, the phylogenetic position of the new species is discussed.