title: Discoplana malagasensis sp. nov., a new turbellarian (Platyhelminthes: Polycladida: Leptoplanidae) symbiotic in an ophiuroid (Echinodermata), with a cladistic analysis of the Discoplana/Euplana species.
abstract: A new species of polyclad flatworm from Papua New Guinea is described. It is found symbiotic in the ophiuroid Ophiothrix purpurea von Martens, 1867 (Echinodermata: Ophiuroidea). Apparently it belongs to the taxon Discoplana Bock, 1913 and can be distinguished from the six previously described Discoplana species by its very short ejaculatory duct and a penial papilla covered with a penial sheath, but without any true sclerotised structures such as a stylet or spines. The cladistic analysis of the Discoplana/ Euplana species, based on morphological features and including two outgroups, reveals that all species of Discoplana, except D. pacificola, form a monophyletic taxon, that is not a synonym of Euplana Girard, 1893. Therefore the name Discoplana is conserved and the new species will be described as Discoplana malagasensis sp. nov. A key for the Discoplana/Euplana group is provided. In this key the biogeographical distribution and possible synonyms are given.
authors.affiliation: Laboratoire de Biologie Marine (C.P. 160/15), Université Libre de Bruxelles. gdoignon@ulb.ac.be .
authors.forename: Gilles
authors.initials: G
authors.lastname: Doignon
authors.forename: Tom
authors.initials: T
authors.lastname: Artois
authors.forename: Dimitri
authors.initials: D
authors.lastname: Deheyn
mesh_terms: D000818:Animals; D004447:Echinodermata; D010802:Phylogeny; D010986:Platyhelminths / Q000033:anatomy & histology / Q000145:classification* / Q000502:physiology*; D013045:Species Specificity; D013559:Symbiosis