Uniflagellate spermatozoa in Nemertoderma (Turbellaria) and their phylogenetic significance

Science  16 May 1975:
Vol. 188, Issue 4189, pp. 730-732
DOI: 10.1126/science.1124394


An ultrastructural study of Nemertoderma (Turbellaria, Nemertodermatida) has revealed that its spermatozoa have only a single falgellum. This is the first uniflagellate spermatozoon known in the Turbellaria; it is indicative of the primitiveness of Nemertoderma and is evidence in support of the view that the Turbellaria as a whole are among the most primitive living Bilateria.