Zoological Studies

Vol. 59, 2020

(update: 2020.05.22; 07.10)

Lacydoniidae (Annelida) Off the Coast of North-eastern Japan: A Description of Lacydonia japonica sp. nov.

Natsumi Hookabe1,*, Naoto Jimi2, Shinji Tsuchida3, Yoshihiro Fujiwara3, and Hiroshi Kajihara4


1Misaki Marine Biological Station, Graduate School of Science, The University of Tokyo, Miura 238-0225, Japan. *Correspondence: E-mail: sofeechan312@gmail.com (Hookabe)
2Bioscience Group, National Institute of Polar Research, Tachikawa 190-8518, Japan. E-mail: beniimo7010@gmail.com (Jimi)
3Marine Biodiversity and Environmental Assessment Research Center, Japan Agency for Marine-Earth Science and Technology,
Yokosuka 237-0061, Japan. E-mail: tsuchidas@jamstec.go.jp (Tsuchida); fujiwara@jamstec.go.jp (Fujiwara)
4Graduate School/Faculty of Science, Hokkaido University, Sapporo 060-0810, Japan. E-mail: kajihara@eis.hokudai.ac.jp (Kajihara)

(Received 13 November 2019 / Accepted 14 May 2020)
Communicated by Benny K.K. Chan

Lacydonia japonica sp. nov. (Annelida, Lacydoniidae) is described based on material found in sediments collected off the Pacific coast of northern Honshu, Japan, at depths of 262 m and 407 m. The sediments were obtained by a remotely operated vehicle equipped with a suction sampler during a Tohoku Ecosystem-Associated Marine Sciences (TEAMS) project in 2019. Lacydonia japonica sp. nov. belongs to the eyeless group of lacydoniids and is discriminated from the morphologically most similar congener, Lacydonia papillata Uschakov, 1958 by its reddish pigments on both the dorsal and ventral parapodial cirri and four pigment spots on the pygidium. To assess the phylogenetic position of the new species among other lacydoniids for which sequence data are available in public databases, analyses were performed using the mitochondrial cytochrome c oxidase subunit I (COI) and 16S rRNA, as well as the nuclear 18S rRNA and 28S rRNA genes. We additionally obtained some lacydoniids by sledging off western Japan, but these were severely fragmented and broken during collection. Using the paucity of morphological data, they were left unidentified as Lacydonia sp. but included in the molecular analyses. Genetic distances between Lacydonia eliasoni Hartmann-Schröder, 1996, Lacydonia japonica, and Lacydonia sp. off western Japan were 10.4–17.1% uncorrected p-distance (11.3–18.6% K2P) in terms of 658-bp COI sequences.

Key words: Benthos, Deep sea, Marine invertebrates, Polychaetes, ROV.

Citation: Hookabe N, Jimi N, Tsuchida S, Fujiwara Y, Kajihara H. 2020. Lacydoniidae (Annelida) off the coast of north-eastern Japan: a description of Lacydonia japonica sp. nov. Zool Stud 59:28. doi:10.6620/ZS.2020.59-28.