Taxonomy,morphology and molecular systematics of a new oligotrich ciliate,Williophrya maedai gen. nov., sp. nov., with redescriptions of Strombidium basimorphum and Pseudotontonia simplicidens (Protozoa,Ciliophora, Oligotrichia)

The morphology and small subunit rRNA (SSrRNA) gene sequence of a marine oligotrich ciliate, Williophrya maedai gen. nov., sp. nov., are reported. The new genus Williophrya is characterized by the adoral zone with no differentiation of membranelles, and the reduced somatic ciliature which comprises a bipartite girdle kinety only. In addition, the in vivo morphologies of two other oligotrichs, namely Strombidium basimorphum Martin & Montagnes, 1993 and Pseudotontonia simplicidens (Lynn & Gilron, 1993 Lynn, D. H. and Gilron, G. L. 1993. Strombidiid ciliates from coastal waters near Kingston Harbour, Jamaica (Ciliophora, Oligotrichia, Strombidiidae). Journal of the Marine Biological Association of the United Kingdom, 73: 47–65. [Crossref] , [Google Scholar]) Agatha, 2004, are reported for the first time based on Chinese populations. Improved diagnoses of both species are supplied. The phylogenetic position of Williophrya maedai is investigated based on SSrRNA gene sequence data. These show that: (1) Williophrya maedai is most closely related to Strombidium purpureum and S. apolatum; (2) Williophrya is assigned to the family Strombidiidae although it has some unique morphological features regarding its oral and somatic ciliatures.