Ocinebrina leukos, Houart, 2000

Houart, Roland, 2000, New species of Muricidae (Gastropoda) from the northeastern Atlantic and the Mediterranean Sea, Zoosystema 22 (3), pp. 459-469 : 465

Ocinebrina leukos n. sp.

( Figs 7-10 )

TYPE MATERIAL. — Holotype in MNHN; paratypes: 6 ( MNHN), 2 ( SMNH), 1 ( BMNH), 3 (coll. R. Houart), 2 (coll. F. Swinnen).

ETYMOLOGY. — From the Greek leukos : white.

MATERIAL EXAMINED. — Lanzarote. Canary Islands, La Isleta , intertidal, 13 lv and dd (holotype and paratypes) ; Lanzarote (no other data), 2 dd (coll. R. Houart).

Orzola. Tide line, 8 lv, 11 dd ( MNHN) ; on rocks, 6 dd (2 paratypes) (coll. F. Swinnen).

TYPE LOCALITY. — Canary Islands, Lanzarote, La Isleta, intertidal.

DISTRIBUTION. — Canary Islands, NW Lanzarote, intertidal ( Fig. 10 ).

DESCRIPTION

Shell large sized for the genus, up to 18.9 mm in length at maturity (holotype), lanceolate, heavy, weakly nodose. Spire very high, with 1.5 protoconch whorls, and up to 6-6.5, broad, convex teleoconch whorls. Suture adpressed. Protoconch small. Whorls rounded, smooth, glossy; ending straight, abrupt.

Axial sculpture of teleoconch whorls consisting of high, broad, rounded ribs. First to third whorls with eleven or twelve ribs, fourth with eleven, fifth with nine or ten, last whorl with eight or nine ribs, and broad, strong terminal varix, occasionally with one or two other erratically placed varices. Spiral sculpture of low, broad, primary and secondary cords, and weak threads. Last whorl, including shoulder, with six or seven primary cords, six or seven secondary cords between each pair of primary cords, and usually a thread between secondary and primary cords.

Aperture small, ovate. Columellar lip narrow, smooth, with small parietal tooth, adherent, briefly and weakly erect abapically. Anal notch broad. Outer lip weakly erect, crenulate, with five,occasionally six strong, broad denticles within. Abapical denticle strongest; when six denticles, adapical (additional) denticle small.Siphonal canal short, weakly dorsally bent, sealed, spirally sculptured.

Uniformly white, dirty-white, or tan-white. Aperture white.

Operculum light brown, D-shaped, with lateral nucleus in lower right. Attached surface with about four growth lines, and broad callused rim.

Radula consisting of a sickle shaped lateral tooth with broad base and a rachidian bearing a short, projecting central cusp, long lateral cusp with inner lateral denticle on base; marginal area with three short denticles and long marginal cusp.

REMARKS

Ocinebrina leukos n. sp. differs from O. edwardsi (Payraudeau, 1826) , that occurs in La Caleta, Lanzarote, sympatrically with O. leukos , in being larger, and very stable in form, sculpture, and colour, while O. edwardsi has a highly variable morphology, even in a same locality, as in La Caleta. O. leukos has constantly a uniform whitish shell with a very high spire, broad axial ribs, broad, rounded outer apertural lip, and broad, voluminous last teleoconch whorl. I never observed a single specimen of O. edwardsi from the Canary Islands, or from any other locality, with these characters combined. Ocinebrina edwardsi may be occasionally (rarely) of a uniform white colour, or may have a broad apertural lip, or a high spire, but then it lacks other characters, peculiar to O. leukos . O. leukos was recorded, and illustrated by Nordsieck & Talavera (1979: 113, pl. 30, fig. 17) as O. nicolai Monterosato, 1884 , a different species known from scattered localities throughout the Mediterranean Sea.

Figures

FIG. 7. — Ocinebrina leukos n. sp. Canary Islands, Lanzarote, La Isleta, intertidal, holotype MNHN, 18.9 mm.

FIG. 8. — Ocinebrina leukos n. sp. Canary Islands, Lanzarote, La Isleta, intertidal, paratype MNHN, 18.4 mm.

FIG. 9. — Radula of Ocinebrina leukos n. sp. La Isleta, Lanzarote, Canary Islands. Scale bars: A, 50 µm; B, 20 µm.

FIG. 10. — Distribution map of Ocinebrina leukos n. sp. (Lanzarote, Canary Islands).