Revision of the genus Phyrella (Holothuroidea: Dendrochirotida) with the description of a new species from Guam

摘要

Recently collected material from Australia, Japan and Guam allowed us to revise Phyrella and describe Phyrella mookiei sp. nov. We redefine the genus based on combined morphological and molecular analyses. Phyrella unlike most dendro-chirotids eviscerate posteriorly. The number of tentacles is variable (14-20), as is the degree of fragmentation of the calcareous ring, calling into question the separation of Phyllophorinae and Semperiellinae, and suggest that Semperiella and Tbyonidiella are synonymous with Phyrella. We recognize five species in Phyrella (Phy/lophorus trapezus Clark, 1932, Phyllophorus fragilis Mitsukuri & Ohshima, 1912 (synonymized with Thyonidiella oceana Heding & Panning, 1954), Phyllophorus thyonoides Clark, 1938, Semperiella drozdovi Levin & Stepanov, 1999, and Phyrella mookiei), assign three others provisionally (Lipolrapeza ambigua Cherbonnier, 1988 (synonymized with Phyllophorus contractura Cherbonni-er. 1988 and Thyonidiella cherbonnieri Rowe & Richmond, 2004), Phyllophorusbedoti Koehler, 1895, and Orcula tenera Ludwig, 1875), considering the last two species inquirenda. Pliyre/la aculeatus (Ludwig, 1894), is transferred to Euthy-onidiella. Orcula (Phyllophorus?) dubia Bedford, 1899, Thyonidiella exigua Cherbonnier, 1988and Thyonidiella kungi O'Loughlin, 2012 are provisionally transferred to Phyllophorus sensu lato, the first is considered species inquirenda. Molecular phylogenetic analysis recovers a well-supported Phyrella, but suggests that some genera and subfamilies of Phyl-lophoridae are not monophyletic.