Cranopsis nymphalis, Simone, Luiz Ricardo L. & Cunha, Carlo M., 2014

Simone, Luiz Ricardo L. & Cunha, Carlo M., 2014, Taxonomical study on the mollusks collected in Marion-Dufresne (MD 55) and other expeditions to SE Brazil: the Fissurellidae (Mollusca, Vetigastropoda), Zootaxa 3835 (4), pp. 437-468 : 443-444

Cranopsis nymphalis new species

Figures 31–39

Types. Holotype MNHN 25293. Paratypes: MNHN 25294, 19 shells, MZSP 107717, 1 shell ( Figs 37–39 ), MZSP 102927, 14 shells, MNRJ 25958, 5 shells, all from type locality. Brazil. Espírito Santo; continental slope of Abrolhos (MD55; Bouchet, Leal & Métivier col.; 27/v/1987); off Itaúnas, 18°59’S 37°48’W, 607–620 m, MNHN 25295, 2 shells (sta. DC73); off Regência, 19°40’S 37°48’W, 790–940 m, MNHN 25296, 1 shell (sta. CB77).

Type locality. Brazil. Espírito Santo; off Itaúnas, continental slope of Abrolhos, 18°59’S 37°50’W, 295 m (MD55 sta. DC75; Bouchet, Leal & Métivier col., 27/v/1987).

Diagnosis. Apex curved downwards, located close to apertural level. Height 47% of length; width ca. 80% of length. Sculpted by ca. 40 strong radial ribs, relatively narrow, profile rounded, bearing transverse low scales extending to narrow interspaces of ribs. Fissure flanked by low, thread-like edges; located close to anterior edge, not completely separated from edge.

Description. Shell size up to 10 mm, low, limpet-like; height 47% of length. Pure white. Protoconch of 1.5 rounded whorls (Fig. 35); situated to right at posterior edge of apex (Figs 35–36); smooth, glossy; size 250 µm. Foramen cuneiform (pointed anteriorly), width ca. 12% of length; located anteriorly, barely open (possibly juveniles); 7% of shell width, 42% of shell length; edges irregular (Figs 31, 32, 34). Profile with beak curved ventrally, located on posterior edge (in dorsal view) (Fig. 33); teleoconch of one whorl; profile highly curved ventrally, sagittal profile as ark (center in middle level of dorsal surface, ca. 10% ventrally off aperture; Figs 33). Sculpture of ca. 40 regular primary radial ribs (Figs 32, 33), with rounded profile; secondary ribs initially rather fine, gradually increasing to size of primary ribs at margin; transverse, semilunar, low nodes as thickenings at intersection with radial sculpture, disposed along ribs in regular spaces equivalent to ca. 1/2 of ribs’ width; nodes continuing between ribs forming series of squared pits; interspaces between successive radial ribs ca. 1/3 their width; ca. 60 scales along ribs close to median line. Selenizone well-marked, as wide as fissure; edges barely taller than radial ribs, continuation from those of fissure, with sharp edges ( Figs 37, 38 ); lunules well-spaced (Figs 31–32). Aperture planar (Fig. 33) elliptical in outline, width ca. 80% of length; edges undulating by radial sculpture. Inner surface smooth, glossy (Fig. 34); bearing several minute, radially aligned pits ( Fig. 39 ). Septum very small, ca. 5% of shell height; as long as wide, ventral edge slightly concave, ca. 8% of aperture width; transforming into simple projected posterior edge of fissure (Figs 31, 32, 34, 39).

Measurements (in mm). Holotype: 7.2 by 5.0; Paratype MZSP 107717: 3.1 by 1.5 ( Figs 37–39 ).

Distribution. Known only from type locality.

Habitat. Sandy mud bottoms, 295–940 m depth (dead specimens).

Material examined. Types.

Etymology. The specific epithet is derived from Greek, nympha, meaning bride, maiden spirit supposed to inhabit the sea and other natural places; an allusion to special, pretty radial sculpture of the shell.

Figures

FIGURES 37 – 39: Cranopsis nymphalis n. sp. paratype MZSP 107717 (L 3.1 mm), a young specimen in SEM. Fig. 37: left view. Fig. 38: dorsal-slightly left view. Fig. 39: ventral view. FIGURE. 40: holotype of Cranopsis antillana (Farfante, 1947), MCZ 160518 (L 11.5 mm); right view. Fig. 41: same, ventral and dorsal views. FIGURES 42 – 47: Cranopsis enigmatica n. sp. Fig. 42: holotype MNHN 25297 (L 2.8 mm), dorsal-slightly left view. Fig. 43: same, right view. Fig. 44: same, ventral view. Fig. 45: Paratype MZSP 102941, SEM (L 2.3 mm), left view. Fig. 46: same, dorsal = slightly left view. Fig. 47: same, detail of middle region of right side, scale = 0.5 mm.