Exploring the basal topology of the heteronemertean tree of life: establishment of a new family, along with turbotaxonomy of Valenciniidae (Nemertea: Pilidiophora: Heteronemertea) Author Kajihara, Hiroshi Author Abukawa, Shushi Author Chernyshev, Alexei V. text Zoological Journal of the Linnean Society 2022 196 503 548 journal article 10.1093/zoolinnean/zlac015 372f8265-c53c-43fa-9448-07d5a58d311f 0024-4082 7037958 78C56409-FCCF-4116-8D8C-FF66B247C56C BASEODISCUS KOMATSUI SP. NOV. ( FIGS 2K , 6F ) Z o o b a n k r e g i s t r a t i o n: u r n: l s i d: z o o b a n k. org:act: 28FE54EB-D2A3-4D1F-9A60-302696A12338 . Material examined: Two specimens; detailed depth information lacking for both, but probably< 20 m depth . Holotype , NMNS-Ne 1 (DNA voucher ICHUM 6342 ), 27 June 2014 , subtidal, SCUBA diving, Nishijima-Oiwa ( 27°07′06″N , 142°10′19″E ), Ogasawara Islands , Japan , collected by H. Komatsu. Paratype , ICHUM 6312 , 27 May 2001 , subtidal, SCUBA diving, among coral rubble, Kakeroma-jima ( c . 28°7′29″N , 129°14′41″E ), Kagoshima , Japan , collected by H. Kajihara. Sequences: From the holotype : LC178597 , 18S (1775 bp) ; LC178627 , 28S (2107 bp) ; LC178648 , H3 (331 bp) ; LC178673 , 16S (504 bp). From the paratype : LC178596 , 18S (1798 bp) ; LC178626 , 28S (2123 bp) ; LC178672 , 16S (479 bp) . Etymology: The new specific name is a noun in the genitive case, after Dr Hironori Komatsu (National Museum of Nature and Science, Japan ), a Japanese carcinologist, who collected the holotype specimen. Description: Background body colour beige, uniformly mottled with brown to dark-olive dots and lines on dorsal, ventral and lateral surfaces of body ( Figs 2K , 6F ). Eyes and cephalic furrows (with secondary furrows) present, as in congeners. In life, holotype 120 cm long, 8 mm wide; paratype , 16 cm long, 2.5 mm wide. Distribution: So far known from the Ogasawara Islands ( type locality) and the island of Kakeromajima in Japanese waters, but probably more widely distributed in warm waters in the western Pacific. Remarks: The mottling pattern in Baseodiscus komatsui resembles that in B. takakurai , but the two species differ in body colour: the mottling is much paler in the former than in the latter, where it is dark brown or black; the background colour is light beige in B. komatsui , yellowish in B. takakurai . The mottling tends to be blurred in the posterior part of the body in B. komatsui . These two species differ at six of the 220 amino-acid positions translated from the 658-bp COI sequences: positions 118 and 122, alanine in B. komatsui , serine in B. takakurai ; 126, glycine in B. komatsui , alanine in B. takakurai ; 154, isoleucine in B. komatsui , valine in B. takakurai ; 159, arginine in B. komatsui , leucine in B. takakurai ; 190, glycine in B. komatsui , alanine in B. takakurai .