Phylogeny of Oweniidae (Polychaeta) based on morphological data and taxonomic revision of Australian fauna

Abstract

The family Oweniidae Rioja, 1917 is a small group of broadly distributed polychaetes whose relationships and position in the annelid tree are still poorly understood. A comprehensive revision of the group with reconsideration of character homologies and terminology under a phylogenetic framework was needed. We investigated the relationships of members of Oweniidae and other polychaetes by performing maximum parsimony analyses of 18 oweniid species of the five recognized genera to date and members of the families Siboglinidae, Sabellidae, Spionidae, Magelonidae, and Chaetopteridae. Phylogenetic hypotheses confirmed the monophyly of Oweniidae and suggested sister-group relationships with Magelonidae, although weakly supported. Analyses also recovered Oweniaand Myriowenia as monophyletic and allowed recognition of Myrioglobulaas a junior synonym of Myriochele based on the presence of acicular chaetae and the shape of the head. Implied weighting analyses supported these findings and recovered Galathowenia australis as sister group ofMyriochele. The presence of acicular chaetae justifies the consideration of this species as belonging to Myriochele. Nomenclatural changes are proposed for those species previously considered as members ofMyrioglobula, and these are: Myriochele antarcticacomb. nov., Myriochele japonicacomb. nov., Myriochele islandicacomb. nov., Myriochele malmgrenicomb. nov., and Myriochele australiscomb. nov. After analyses and definition of generic diagnostic features, other new combinations include Galathowenia eurystomacomb. nov. and Galathowenia haplosomacomb. nov., previously considered as members of Myriochele. Taxonomic revision of Australian collections revealed the presence ofMyriochele heruensis Gibbs, 1971, which is herein redescribed, and allowed the description of four new species: Galathowenia annae sp. nov.,Galathowenia arafurensissp. nov., Galathowenia quelissp. nov., andMyriochele australiensissp. nov., mostly from the east coast of Australia, in addition to the three recently well-documented species of Owenia. Australian species have been described, illustrated, and compared in detail with similar taxa. Distribution patterns and ecological notes have also been given. Keys to oweniid genera and Australian species are provided.