ハセガワ　ナオヒロ   HASEGAWA Naohiro   長谷川　尚弘    所属   広島修道大学  人間環境学部    職種   助教
言語種別	英語
発行・発表の年月	2025/05
形態種別	学術論文
査読	査読有り
標題	Description of a new species of Eusynstyela (Ascidiacea: Stolidobranchia) from Okinawa, Japan with molecular insight into its phylogenetic position
執筆形態	単著
掲載誌名	Species Diversity
掲載区分	国外
出版社・発行元	The Japanese Society of Systematic Zoology
巻・号・頁	30,pp.99-106
担当範囲	単著ゆえにすべて
著者・共著者	Hasegawa N
概要	The colonial styelid genus Eusynstyela Michaelsen, 1904 comprises 12 species. Seven colonies of Eusynstyela were collected via SCUBA diving from three coastal sites in Okinawa, Japan, between 2018 and 2023. Morphological observations in this study identified these specimens as a new species, described here as Eusynstyela sesokoensis sp. nov. This species can be distinguished from its congeners by the following characteristics: i) ten oral tentacles, ii) twelve stomach plications, iii) absence of a stomach caecum, iv) no lobes on the anal rim, and v) two testes per gonad. Intraspecific variations were observed in zooid coloration and the number of longitudinal vessels on the pharyngeal folds. The molecular phylogenetic analysis based on a partial sequence of 18S rRNA and the mitochondrial cytochrome c oxidase subunit I genes indicates a possible sister relationship between the new species and E. latericius (Sluiter, 1904).