title: Morphological and molecular revision of Zoanthus (Anthozoa: Hexacorallia) from southwestern Japan, with descriptions of two new species.
abstract: No clear method of identifying species in the zoanthid genus Zoanthus has been established, due in part to the morphological plasticity of this genus (e.g., in polyp and colony form, oral disk color, tentacle number). Previous research utilizing the mitochondrial cytochrome oxidase I gene (COI) as a phylogenetic marker indicated that Zoanthus spp. in Japan may consist of only one or two species, despite a bewildering variety of observed morphotypes. Here we have utilized not only COI but also mitochondrial 16S ribosomal DNA (mt 16S rDNA) in order to clarify the extent of Zoanthus species diversity in southern Japan. Our molecular genetic results clearly show the presence of three monophyletic Zoanthus species groups with varying levels of morphological plasticity, including the new species Z. gigantus n. sp. and Z. kuroshio n. sp. We describe all three species found in this study, and identify potential morphological characters (coenenchyme and polyp structure as well as polyp external surface pigmentation patterns) useful in Zoanthus species identification. A morphological dichotomous key is provided to assist in field species identification.
authors.affiliation: Research Program for Marine Biology and Ecology, Extremobiosphere Research Center, Japan Agency for Marine-Earth Science and Technology (JAMSTEC), Kanagawa, Japan. jreimer@jamstec.go.jp
authors.forename: James Davis
authors.initials: JD
authors.lastname: Reimer
authors.forename: Shusuke
authors.initials: S
authors.lastname: Ono
authors.forename: Atsushi
authors.initials: A
authors.lastname: Iwama
authors.forename: Kiyotaka
authors.initials: K
authors.lastname: Takishita
authors.forename: Junzo
authors.initials: J
authors.lastname: Tsukahara
authors.forename: Tadashi
authors.initials: T
authors.lastname: Maruyama
mesh_terms: D000818:Animals; D037421:Anthozoa / Q000033:anatomy & histology / Q000145:classification* / Q000201:enzymology / Q000235:genetics*; D001483:Base Sequence; D004272:DNA, Mitochondrial / Q000235:genetics; D004275:DNA, Ribosomal / Q000737:chemistry; D003576:Electron Transport Complex IV / Q000235:genetics*; D019143:Evolution, Molecular; D014644:Genetic Variation; D007564:Japan; D008969:Molecular Sequence Data; D010802:Phylogeny; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA; D013045:Species Specificity
chemical_list: D004272:DNA, Mitochondrial; D004275:DNA, Ribosomal; D012336:RNA, Ribosomal, 16S; D003576:Electron Transport Complex IV