A taxonomic review of the genusAstrocladus(Echinodermata, Ophiuroidea, Euryalida, Gorgonocephalidae) from Japanese coastal waters

Abstract

Japanese species of the genusAstrocladus(Echinodermata, Ophiuroidea, Euryalida, Gorgonocephalidae) are reviewed.Astrocladus coniferusrecently has two junior synonyms,A. dofleiniDöderlein andA. pardalisDöderlein, however, status of these species has long been questioned. These species concepts have not been reviewed in recent years and no molecular phylogenetic analyses have been performed. Observations of the lectotype ofA. coniferus, as well as the lectotype and four paralectotypes ofA. dofleiniand the holotype ofA. pardalishave revealed thatA. coniferusandA. pardalisare conspecific and morphologically distinguishable fromA. dofleini.Astrocladus coniferusandA. dofleiniare supported as distinct species by our molecular data. Additionally, we re-describeA. exiguusandA. annulatus, based on recently collected specimens and the holotype. We conclude that four species,A. annulatus,A. coniferus,A. dofleini, andA. exiguusare present in Japanese waters.