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 OHTSUKAI SP. NOV. ( FIG. 7D, E ) 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: 5DBE9E10-9A24-447B-9A7F-EE5DD10891E0 . Material examined: Holotype , ICHUM 6327 , 29 May 2001 off Toi Cape ( 31°19′12″N , 131°21′00″E ), Kagoshima , Japan , 118 m depth , station 12 of the R / V Toyoshio-maru Cruise 01-06, collected by H. Kajihara. Sequences: From the holotype : LC178592 , 18S (1799 bp) ; LC178622 , 28S (2117 bp) ; LC178667 , 16S (456 bp) ; LC190945 , COI (629 bp) . Etymology: The new specific name is a noun in the genitive case, from Prof. Susumu Ohtsuka, a Japanese crustacean biologist, leader of marine biodiversity studies with the R/V Toyoshio-maru of Hiroshima University. Description: Body broad, dorsoventrally flattened, 15 cm long, 4 mm wide; ground colour white, dorsally with wide purplish brown stripe, ventrally with minute flecks of same colour (lacking in front of cephalic furrow); transverse cephalic furrow present, encircling neck; secondary furrows present; small, black ocelli distributed along dorso-lateral surfaces of head; proboscis pore sub-terminal; mouth small ( Fig. 7D, E ). Found in mucus tube formed with mud and sand particles. Distribution: So far known only from the type locality, sublittoral, off southern Kyushu in the Pacific (present study). Remarks: Baseodiscus ohtsukai looks similar to B. urgorrii in that it has a whitish background colour and a broad, mid-dorsal longitudinal stripe, but differs from the latter in the colour of the stripe, which is more reddish than that in B. urgorrii .