The morphology, ontogeny, and small subunit rRNA gene sequence analysis of Diophrys parappendiculata n. sp. (Protozoa, Ciliophora, Euplotida), a new marine ciliate from coastal waters of southern China.

The morphology, morphogenesis, and phylogeny of Diophrys parappendiculata n. sp., a large marine ciliate isolated from the coastal waters of Daya Bay, southern China, were investigated. This new species is characterized by a combination of its large size, appendiculata-pattern of ciliature, and bipartite adoral zone of membranelles. The main stages of morphogenesis during binary fission were also recorded and described. Comparisons of morphological characteristics with similar congeners support the validity of the new species. The small subunit rRNA gene sequence of D. parappendiculata is 96.3-99.94% similar to those of four other congeners; it differs in four nucleotides from that of Diophrys appendiculata (i.e. structural similarity was 99.94%). Phylogenetic analysis indicates that D. parappendiculata n. sp. falls into the Diophrys clade and is most closely related to the well-known D. appendiculata.