Histology-free description and phylogenetics of Tetrastemma parallelos sp. nov. (Nemertea: Eumonostilifera) from Japan

ABSTRACT

We report a histology-free description of the eumonostiliferous hoplonemertean Tetrastemma parallelos sp. nov. based on a single specimen dredged from a depth between 11 and 18 m off Kouyatsu, Tateyama, Chiba, Japan. Dorsally, T. parallelos sp. nov. is characterised by the presence of two orange-pigmented parallel lines in addition to a reddish cephalic patch. Molecular phylogenetic analyses based on partial sequences of 16S, 18S, 28S rRNA, cytochrome c oxidase subunit I (COI), and histone H3 gene markers along with sequences of 20 Tetrastemma species available in public databases confirmed that our species belongs to a clade recently proposed as the Asian–Australian Pacific subclade of the genus.

http://www.zoobank.org/urn:lsid:zoobank.org:pub:7A50603A-9D73-449D-A2E7-343C20AF3A23

KEYWORDS:

• Hoplonemertea
• Monostilifera
• systematics
• Tetrastemmatidae
• turbo taxonomy

Acknowledgements

We thank Mr Mamoru Yamaguchi (MCRCOU) for the help in collecting the material; Professor Masato Kiyomoto (MCRCOU) for allowing RY to use the facility at MCRCOU; and Professor Alexei V. Chernyshev (A.V. Zhirmunsky National Scientific Centre of Marine Biology, Russia) for providing us descriptions of his undescribed Tetrastemma species.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This study was partially funded by the Japanese Ministry of Education, Culture, Sports, Science and Technology, under a Joint Usage/Education Centre programme, and by the Japan Society for the Promotion of Science KAKENHI [Grant numbers JP20K06780 and JP20H03304 to HK]; Japanese Ministry of Education, Culture, Sports, Science and Technology, under a Joint Usage/Education Centre program the Promotion of Science KAKENHI.