Coptocheilus maunautim, Bui & Páll-Gergely, 2020

Bui, Chinh Thi & Páll-Gergely, Barna, 2020, A new species of Coptocheilus Gould, 1862 (formerly Schistoloma Kobelt, 1902) from Vietnam (Caenogastropoda: Cyclophoroidea: Pupinidae), Raffles Bulletin of Zoology 68, pp. 448-451 : 449-451

Coptocheilus maunautim , new species

( Fig. 1A, C )

Material examined. Holotype (H: 21.7 mm, W: 9.2 mm) (MNHN-IM-2000-35697), Vietnam, Thua Thien- Hue Province, Nam Dong District , limestone mountain (16°06′56″N, 107°38′32″E, 220 m), coll. T. C. Bui, 10 June 2018 . Paratypes: 1 ex. ( HNHM 104870 ) , 1 ex. (coll. HA), 1 ex. ( VNMN _ IZ 000.000.178), 17 exx. ( LZ–HUE 5601 ), all same data as holotype, coll. T. C. Bui, N. T. N. Dang and N. T. Duong, 01 October 2017 and 10 June 2018; 2 exx. ( ZRC.MOL.16453), same data as holotype, coll. T. C. Bui, 10 June 2018; 7 exx. ( LZ–HUE 5602 ), Vietnam, Thua Thien-Hue Province, Nam Dong District , limestone mountain (16°08′16″N, 107°36′51″E, 270 m), coll. T. C. Bui and H.C. Nguyen, 07 July 2018 .

Diagnosis. A middle-sized Coptocheilus species with a brownish purple shell colour, rather glossy, almost smooth shell surface, and a “double suture”.

Description. Shell high conical, widest around base, brownish purple (dead collected shells lighter); protoconch 2.75 whorls, smooth, glossy, orange to purple; teleoconch glossy, nearly smooth, with very fine growth lines; suture “double” (a “pseudosuture” visible as slight groove just below the suture), with a conspicuous pale subsutural band; outer lip slightly opisthocline; peristome continuous, expanded, very slightly reflected, especially at basal part; peristome slender, sharp in lateral view, boundary between inner and outer peristomes hardly visible; umbilicus open, slit-like, without periumbilical keel. Operculum unknown.

Measurements (mm). H: 19.2–23.3, W: 8.5–9.2, AH: 6.6–7.3, AW: 6.4–7.1 (n = 25).

Differential diagnosis. Coptocheilus maunautim , new species, differs from all congeners by its “double suture” (see comparison with C. messageri , Fig. 1B, D ), except for Coptocheilus maydelineae (Páll-Gergely, P.K. Nguyen & Y. Chen, 2019) , which clearly differs by having a strongly ribbed shell. Coptocheilus sectilabris (A. Gould, 1844), which was also reported from Vietnam ( Thach, 2016), is larger, with a more corpulent shell and wider body whorl.

Etymology. The specific epithet ‘maunautim’ (to be used as a noun in apposition) derives from “màu nâu tím”, meaning “a mixture of brown and purple” in Vietnamese, referring to the colour of the shell.

Distribution. This new species is only known from the type locality so far ( Fig. 2 ).

Checklist of Coptocheilus species

The most recent review by Páll-Gergely et al. (2019) erroneously used the generic name Schistoloma (grammatical gender: neutral). Here we provide an updated checklist of the species, now included in Coptocheilus (grammatical gender: masculine), to reflect changes in parentheses around authors’ names in changed combinations and agreement in gender of species names.

Coptocheilus altus (Sowerby I, 1842)

Coptocheilus anostomus ( Benson, 1852)

Coptocheilus cochinchinensis ( Rochebrune, 1882) Coptocheilus doriae ( Issel, 1874)

Coptocheilus funiculalus ( Benson, 1838)

Coptocheilus inermis Bavay & Dautzenberg, 1909

Coptocheilus leferi ( Morelet, 1861)

Coptocheilus longyanensis ( Zhou, Zhang & Chen, 2009)

Coptocheilus maydelineae (Páll-Gergely, P.K. Nguyen & Y. Chen, 2019)

Coptocheilus mcgregori ( Bartsch, 1916)

Coptocheilus messageri Bavay & Dautzenberg, 1909

Coptocheilus pauperculus (Sowerby I, 1850)

Coptocheilus quadrasi ( Hidalgo, 1889)

Coptocheilus sectilabris (A. Gould, 1844)

Coptocheilus sumatranus Dohrn, 1881

Coptocheilus tanychilus ( Godwin-Austen, 1876)

Figures

Fig. 1. A, C, holotype of Coptocheilus maunautim, new species (MNHN-IM-2000-35697), with “double suture” indicated by arrows; B, D, Coptocheilus messageri (SMF 192263) with simple suture indicated with an arrow. Scale a represents 10 mm and refers to fig. A and B, scale b represents 5 mm and refers to fig. C and D.

Fig. 2. Distribution of Coptocheilus species in Vietnam. 1, C. messageri (Bavay & Dautzenberg, 1909); 2, C. inermis (Bavay & Dautzenberg, 1909) (type locality of Pinteria croesus Varga, 1972); 3, C. maunautim, new species; 4, C. sectilabrum (A. Gould, 1844); 5, C. maydelineae (Páll-Gergely, P.K. Nguyen & Y. Chen, 2019); 6, C. cochinchinense (Rochebrune, 1882) (based on Thach, 2016 and Páll-Gergely et al., 2019).