Oxypolella hiebertae, Kajihara & Abukawa & Chernyshev, 2022

Kajihara, Hiroshi, Abukawa, Shushi & Chernyshev, Alexei V., 2022, Exploring the basal topology of the heteronemertean tree of life: establishment of a new family, along with turbotaxonomy of Valenciniidae (Nemertea: Pilidiophora: Heteronemertea), Zoological Journal of the Linnean Society 196, pp. 503-548 : 519

OXYPOLELLA HIEBERTAE SP. NOV.

( FIG. 2B )

Oxypolellinae gen. sp.: Hiebert, 2016: 318.

Zoobank registration: u r n: l s i d: z o o b a n k. org:act: 1F5D91AE-5C57-4E9A-BE20-C05D2DA554B4.

Material examined: Four specimens, all collected by A. V. Chernyshev. Holotype, MIMB 42256 , 23 May 2007, among dead corals, 2–4 m depth, Cù-Lao Ré Island (15°23′N, 109°05′E), Vietnam . Other material: two specimens, 19 May 2007, among dead corals, 5–7 m depth, Bach Long Vi Island (20°09′N, 107°44′E), Vietnam ; one specimen, 22 May 2010, intertidal, among calcareous red algae, Van Phong Bay (12°40′N, 109°20′E), Vietnam .

Sequence: From the holotype; KU748595 , 16S (524 bp), determined by Hiebert (2016) as Oxypolellinae sp. TCH-2017 isolate E4H7.

Etymology: The new specific name, a noun in the genitive case, honours Dr Terra C. Hiebert for her outstanding contribution to nemertean systematics.

Description: Body soft, 2–4 cm long, 1 mm wide, dorsally yellow or lemon yellow, ventrally pale yellowish; head long, narrow, with two thin transverse furrows in front of mouth; eyes and caudal cirrus absent ( Fig. 2B ). Rhynchopore ventral. Mouth small, pit-like. Rhynchocoel extending length of body. Two regions detected in proboscis of live specimens. Frontal organ present (from CSLSM observation; data not shown). Body wall with two dorsal nerves (from CSLSM observation; data not shown). Living worms with distinctive, permanent mucous tube.

Distribution: Known only from Vietnam (present study).

Remarks: Oxypolella hiebertae is the sixth member described in the genus (cf. Cantell, 2005). It resembles the most recently described species, Oxypolella banyulensis Cantell, 2005 from the Mediterranean, in having yellowish body colour. Oxypolella hiebertae differs from O. banyulensis in having cephalic furrows as well as in the body coloration; in O. hiebertae , the body is uniformly yellow, whereas in O. banyulensis , the anterior third of the body is white and the posterior two-thirds yellowish white.

Figures

Figure 2. A, Eopilidion misakiense gen. et sp. nov., holotype, ICHUM 6303, lateral view, head to the right; B, Oxypolella hiebertae sp. nov., holotype, MIMB 42256; C, Cephalomastax brevis Iwata, 1957, ICHUM 6304; D, E, Valencinura jambio sp. nov., holotype, ICHUM 6305, anterior body fragment (D) and enlargement of intestinal region (E) showing yellowish proboscis (indicated by arrowheads); F, Baseodiscus takakurai Gibson, 1995, ICHUM 6306; G, Baseodiscus profundus sp. nov., holotype, MIMB 42257; H, I, Baseodiscus narusei sp. nov., holotype, ICHUM 6310, anterior end of body, dorsal (H) and ventral (I) views; J, Baseodiscus paracelensis sp. nov., holotype, MIMB 33132; K, Baseodiscus komatsui sp. nov., holotype, NMNS-Ne 1; L, Baseodiscus unicolor Stiasny-Wijnhoff, 1925; M, Baseodiscus giribeti sp. nov., holotype, MCZ IZ-135324; N, Baseodiscus cf. amboinensis (Staub, 1900); O, Baseodiscus hemprichii (Ehrenberg, 1828-1831), specimen from Okinawa, different from any voucher specimens in this study; P, Baseodiscus zebra sp. nov., holotype, RUMF-ZN-00001; Q, Baseodiscus quinquelineatus (Quoy & Gaimard, 1833), ICHUM 6319. Photographs by H. Kajihara (A, C, D, E, F, O), A.V. Chernyshev (B, G, J), T. Naruse (H, I), H. Komatsu (K), G. Giribet (L, M), D. Uyeno (P), and R.Yoshida (Q).