Belomitra radula, Kantor & Puillandre & Rivasseau & Bouchet, 2012

Kantor, Yuri I., Puillandre, Nicolas, Rivasseau, Audrey & Bouchet, Philippe, 2012, 3496, Zootaxa 3496, pp. 1-64 : 20-21

Belomitra radula new species

Figures 10, 11

Type material: Holotype MNHN 24480 (measurements: SL 19.5 mm, BWL 11.5, AL 8.4, SW 5.8 mm); paratype MNHN 24481 .

Type locality: Off NW Madagascar, Banc du Castor, 12º34’S, 47º54’E, 367–369 m, 30 June 2009 [MIRIKY sta. DW3212 ] .

Material examined: MADAGASCAR. MIRIKY, sta. DW3212 , 12º34’S, 47º54’E, 367–369 m (1 dd, holotype); sta. CP3223, 12º46’S, 48º11’E, 430–488 m (1 dd, paratype) .

Description (holotype, Fig. 10A–D): Shell medium-sized, strong, turriform, with high, elevated spire, consisting of 6.5 convex teleoconch whorls, slightly angulated at shoulder. Protoconch bulbous, of 1.5 strongly convex whorls, covered with very thin and narrowly spaced spiral threads. Protoconch diameter 1100 µm, height 900 µm. Protoconch-teleoconch transition marked by a weak orthocline rib. Suture impressed. Subsutural ramp well pronounced, narrow, concave. Besides inconspicuous growth lines, axial sculpture consisting of narrow, strong, closely spaced, opisthocline ribs, 23 on penultimate and 29 on last whorl, extending over whole whorl height on spire whorls, less pronounced on shell base. Spiral sculpture of distinct, narrow, sharp cords of uneven strength, covering entire shell surface and more broadly spaced on canal. On intersections with axial ribs cords form small beads, producing a nearly reticulated sculpture. Three cords on subsutural ramp of last whorl, subsutural one strongest. Aperture narrow, elongate. Outer lip evenly convex, except for a slight concavity corresponding to subsutural ramp. Columella nearly straight, with 6 very weak plaits. Callus narrow, of thin transparent glaze overlying parietal region. Siphonal notch absent. Canal short, poorly delimitated from aperture, slightly curved to left. Shell colour off-white. Periostracum very thin, colorless, tightly adherent.

Distribution: North-West Madagascar, off Nosy Be, shells only in 367–488 m ( Fig. 11).

Etymology: From the Latin radula , meaning a file or scraper, in reference to the rough sculpture, used as noun in apposition.

Remarks: The slightly larger paratype, SAL 21.4 mm, with broken apical whorls, is very similar to the holotype, and has a slightly more pronounced sculpture.

Belomitra radula has a sculpture pattern somewhat similar to that of B. reticulata , from which it differs by its smaller size and more pronounced subsutural ramp. It differs from all other Indian Ocean species in overall shell shape and rough beaded sculpture.