Clavus rugizonatus Hervier, 1896

Kilburn, Richard N., Fedosov, Alexander & Kantor, Yuri, 2014, The shallow-water New Caledonia Drilliidae of genus Clavus Montfort, 1810 (Mollusca: Gastropoda: Conoidea), Zootaxa 3818 (1), pp. 1-69 : 10-12

Clavus rugizonatus Hervier, 1896

( Figs. 3 A–I)

Clavus rugizonatus Hervier 1896a: 142 ; Hervier 1896b: 53, pl. 1, fig. 3. Drillia (Clavus) rugizonata ; Bouge & Dautzenberg 1914: 142.

Clavus exasperatus ; Sysoev in Poppe 2008: pl. 673, fig. 4 only (non Reeve, 1843).

Type data. Originally 15 syntypes, present location uncertain (4 syntypes in MNHN IM–2000–3203, IM–2000–3204; doubtful syntypes in IRSNB and NMSA). Type locality: Lifou, New Caledonia.

New caledonian material examined (total 29 lots, 65 spms):

New Caledonia, Nouméa: Campagne d'essais 1987 Stn. DE 55 (2 spms);

LAGON Stns. 79 (1 spm), 379 (1 spm), 453 (1 spm), 644 (1 spm), 650 (1 spm), 755 (1 spm), 1118 (1 spm), 1181 (2 spm), 1212 (1 spm), 1356 (7 spms);

EXPÉDITION MONTROUZIER, Koumac Stns. 1310 (3 spms), 1312 (2 spms), Touho Stn. 1269 (1 spm);

Loyalty Islands, Lifou: LIFOU 2000, Stns. 1415 (1 spm), 1420 (1 spm), 1421 (5 spms), 1425 (5 spms), 1424 (2 spms), 1426 (8 spms), 1427 (1 spm), 1432 (1 spm), 1433 (1 spm), 1444 (8 spms), 1448 (1 spm), 1449 (1 spm), 1451 (1 spm), 1453 (1 spm),

Coral Sea, MUSORSTOM 5, Stn. DW264 (1 spm).

Distribution. New Caledonia, Loyalty Islands and Coral Sea, 1–70 m, mainly in sediment and sand between coral on reef bottoms, no live collected specimens were available, but the shells collected below 40 m were strongly worn and probably occurred there due to vertical transposition.

Description. Broadly biconic-claviform with sharp, orthoconoid spire (breadth/length 0.42–0.52), and relatively wide aperture (aperture/total length 0.35–0.40), evenly truncate base, termination of siphonal canal concavely indented; fasciole strong; suture narrowly undercutting succeeding whorl, irregularly undulating. Outer lip somewhat alate below anal sinus, in side view rather weakly convex, serrated, anal sinus openly U-shaped, directed adapically, parietal nodule large, stromboid notch distinct but shallow; columella with a wide, rounded callus.

Subsutural region adpressed to base of previous whorl, sloping; axial ribs extending from suture (where they form weak folds) to periphery, where they form projecting, slightly outwardly directed, squamiform spines (sometimes merely angular nodules); seven arcuate, suture-to-suture ribs on first teleoconch whorl, 8–11 ribs on later whorls, spines in t/s sharp, with high, scale-like tips, steeply sloping, concave sides, near base on early whorls, median on penultimate one; sometimes a low ridge joining spines. Last whorl with a broad zone of coarse granules extending from periphery to parietal level and even rostrum; granules usually aligned spirally as well as obliquely, into bifurcating or vermiculate lines, sometimes forming distinct ridges. Base often with a row of prominent granules at level of anterior edge of parietal tubercle. Surface with a microsculpture of collabral threads and extremely fine, irregularly sloping spiral striae. Rostrum with 5–7 declivous spiral ridges.

White, with a broad deep orange-brown zone at mid-last whorl, sometimes with a darker border above, aperture (including parietal pad) white. Occasionally speckled overall with pale reddish-brown, with a dark brown band below periphery, interrupted by bases of ribs. Protoconch dark yellowish-brown, contrasting with the white teleoconch whorls that follow.

Protoconch ( Fig. 3 I) narrowly domed, of about two smooth whorls (under SEM a series of very fine plicules visible below suture); breadth 830 µm, height 630 µm.

Measurements. 23.4 x 10.9 mm (largest available); smallest adult 14.1 x 8.3 mm; 15.8 x 7.3 mm (narrow example).

Radula. Not available.

Remarks. This species is highly variable, not only in colouration and adult size but in the development of its shoulder tubercles. When unworn, the latter may be almost as prominent as in typical examples of Clavus canalicularis , yet in other individuals they are scarcely stronger than in C. exasperatus . C. rugizonatus is characterised by its strongly granulose and pustulose basal zone. The combination of variously sized and shaped pustules, together with the crispate growth lines, give the base of the last whorl a curiously rasp-like appearance.

Other than a single unconfirmed specimen from Hawaii in the NMSA, this species is known to us only from New Caledonia.

Figures

FIGURE 3. Clavus rugizonatus Hervier, 1895. A, B. Possible syntype of Clavus rugizonatus MNHN IM – 2000 – 3204, Loyalty Islands, Lifou, 19.3 x 10.9 mm; C. Molecular voucher IM – 2009 – 19172, Philippines, Panglao Is, PANGLAO 2004 Stn. B 9, 9 ° 33.1 ' N 123 ° 44.0 ' E, 8 – 10 m; D. Narrow example, Loyalty Islands, Lifou, LIFOU 2000, Stn. 1425, 15.8 x 7.3 mm; E, F. New Caledonia, EXPÉDITION MONTROUZIER, Touho Stn. 1269, 18.3 x 8.0 mm; G, H. New Caledonia, LAGON, Stn. 755, Canala Sector, SL 22.8 mm; I. Protoconch, Loyalty Islands, Lifou, LIFOU 2000, Stn. 1424.