Dermomurex Monterosato, 1890

Houart, Roland & Héros, Virginie, 2013, Description of new Muricidae (Mollusca: Gastropoda) collected during the ATIMO VATAE expedition to Madagascar “ Deep South ”, Zoosystema 35 (4), pp. 503-523 : 511-514

Subgenus Dermomurex Monterosato, 1890

TYPE SPECIES. — Murex scalarinus Bivona-Bernardi, 1832 (junior synonym of Murex scalaroides Blainville, 1829 ), Mediterranean (by original designation).

REMARKS

The genus Dermomurex is not widely present in the Indo-West Pacific. Only two species have been recorded from the western Indian Ocean, both from South Africa, in the vicinity of Zululand: Dermomurex (Takia) africana Vokes, 1978 and D. (T.) infrons Vokes, 1974 .

Dermomurex was included by Keen (1971) in the subfamily Aspellinae Keen, 1971 , along with the type genus Aspella Mörch, 1877 . Based on radular features, Dermomurex and Aspella are similar to muricines in having a flat pentacuspidate rachidian tooth.

The results obtained by Barco et al. (2010) give high support to a clade composed of Dermomurex , Attiliosa Emerson, 1968 and the Muricopsinae Radwin & D’Attilio, 1971 , but the most appropriate subfamilial classification remains uncertain, because they are not retrieved as a monophyletic group. Aspella was missing in the dataset, but close similarity with Dermomurex is an undeniable fact, and it is possible that its inclusion in future work might support the recognition of the subfamily Aspellinae .

Dermomurex (Dermomurex) charlesi n. sp. ( Figs 1C ; 5 A-C; 7H)

TYPE MATERIAL. — Holotype MNHN 26511 and 5 paratypes MNHN 26512-26514 , 1 RH.

TYPE LOCALITY. — South Madagascar, SW Cap Sainte Marie, 25°48.4’S, 44°51.1’E, 44-46 m ( ATIMO VATAE: stn DW 3606).

MATERIAL EXAMINED. — ATIMO VATAE: stn CP3579, Sud de Faux-Cap, 25°54.5’S, 45°33.2’E, 65-66 m, 1 dd (paratype MNHN 26512). — Stn DW3605, SW Cap Sainte Marie, 24°54.5’S, 44°51.0’E, 56-57 m, 1 dd, juv (paratype MNHN 26513). — Stn DW3606, SW Cap Sainte Marie, 25°48.4’S, 44°51.1’E, 44-46 m, 1 dd (holotype MNHN 26511). — Stn DW3607, SW Cap Sainte Marie, 25°45.7’S, 44°52.0’E, 40-41 m, 1 dd (paratype RH). — Stn CP3624, Sud-Est Faux-Cap, 25°38.1’S, 45°57.0’E, 63 m, 3 dd (paratypes MNHN 26514).

DISTRIBUTION. — South Madagascar, shells in 41- 65 m.

ETYMOLOGY. — This species is named after Laurent Charles, curator at the Muséum d’Histoire Naturelle in Bordeaux. Laurent was a member of the ATIMO VATAE expedition field party and of several subsequent MNHN expeditions, combing skills as a collector, sorter and photographer of living micromolluscs.

DESCRIPTION

Shell medium-sized for the subgenus, up to 11.6 mm in height at maturity (holotype). Height/width ratio 2.0-2.1. Biconical, narrowly-ovate, weakly nodose, lightly built. Subsutural ramp narrow, weakly sloping, convex. Shell entirely covered by thick, dirty-white intritacalx with faint, shallow spiral striae, otherwise smooth, with deep pits along axial varices. Shell entirely white. Aperture light peach within.

Spire high with 1.5 protoconch whorls and teleoconch up to 5+ weakly convex, weakly shouldered, nodose whorls. Suture strongly impressed. Protoconch small, whorls rounded, smooth; maximum width 700-800 µm, height 700 µm. Terminal lip narrow, erect, weakly rounded, oblique.

Axial sculpture of teleoconch whorls consisting of narrow varices decreasing in height and becoming broader adapically. First teleoconch whorl with six varices that overlap onto the protoconch. Second to penultimate whorl with six varices. Last whorl with four or five low, broad varices. Spiral sculpture weak, flat, broad. Primary cords indistinguishable on adapical teleoconch whorls. Last whorl with low, broad, weakly nodose P1-P6.

Aperture moderately small, ovate. Columellar lip narrow, smooth, rim adherent, weakly detached abapically. Anal notch indiscernible. Outer lip smooth, smooth within or with very weak, broad, low denticles: D1-D6, of which only (D2-D3), D4, D5 and D6 are visible in the holotype. Siphonal canal short, broad, weakly dorsally recurved, open.

Operculum and radula not examined.

REMARKS

Dermomurex (Dermomurex) charlesi n. sp. is here compared with three Australian species: D. (D.) agnesae Vokes, 1995 from Western Australia, D. (D.) angustus (Verco, 1895) from South Australia and D. (D.) goldsteini (Tenison-Woods, 1876) from New South Wales and Tasmania.

Dermomurex (D.) agnesae ( Fig. 5F, G ) differs in having a comparatively larger and broader shell with a height/width ratio of 1.9 vs 2.0- 2.1 in D. (D.) charlesi n. sp., and in having a conical, acute spire with only five axial varices from the second to the last teleoconch whorls ( Vokes 1985) and a somewhat larger aperture.

Dermomurex (D.) angustus differs in having a more slender and elongate shell (height/width ratio 2.2- 2.4) with distinctive, rounded, broad axial varices.

Dermomurex (D.) goldsteini ( Fig. 5D, E ) is a comparatively somewhat larger shell, reaching 21 mm in height, with a comparatively smaller aperture, slightly more strongly shouldered teleoconch whorls and more conspicuous, higher spiral cords.

Figures

FIG. 1. — Distribution of the six new species described herein: A, Chicoreus (Triplex) kantori n. sp.; B, Naquetia manwaii n. sp.; C, Dermomurex (Dermomurex) charlesi n. sp.; D, Favartia (Favartia) tantelyi n. sp.;E, Favartia (Pygmaepterys) fournierae n. sp.; F, Semiricinula bozzettii n. sp. Symbols: Ê, type locality; £, other occurences.

FIG. 5. — A-C, Dermomurex (D.) charlesi n. sp.; A, B, holotype MNHN 26511, 11.6 mm; C, paratype MNHN 2651, 8.2 mm; D, E, Dermomurex (D.) goldsteini (Tenison-Woods, 1876), Gerringong, S. NSW, Australia, 15.8 mm, RH; F, G, Dermomurex (D.) agnesae Vokes, 1995, holotype WAM 209-94, 13.9 mm (photo courtesy E. H. Vokes; scan of a white and black photograph); H-K, Favartia (F.) tantelyi n. sp.; H, I, holotype MNHN 26515, 8.1 mm; J, K, paratype MNHN 26516, 15.7 mm; L, Favartia (F.) eastorum Houart, 1998, Peak Id, N. of Exmouth Gulf, W. Australia, 18.7 mm, paratype RH; M, N, Favartia (F.) brevicula (Sowerby, 1864), Mauritius, 30.8 mm, coll. RH.