Clavus virginieae, Kilburn, Richard N., Fedosov, Alexander & Kantor, Yuri, 2014

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 : 36-38

Clavus virginieae new species

( Figs. 17 A–G, 18 A, B)

Type material. Holotype: Loyalty Islands, Lifou, LIFOU 2000, Baie du Santal, between Cap Wekutr and Cap Wajez, Stn. 1455, 20°56.8’S, 167°02.7’E; 15–20 m, MNHN IM–2000–26924. Paratypes: Loyalty Islands, Lifou, LIFOU 2000, Stn. 1432, 20°53.5’S, 167°02.7’E, 12–32 m (8— MNHN IM–2000–26925); Stn. 1441, 20°46.4’S, 167°02.0’E, 20 m (1 + 2 juv. — MNHN IM–2000–26926); Stn. 1445, 20°50.8’S, 167°09.7’E, 10–12 m (2— MNHN IM–2000–26927); Stn. 1447, 20°45.8’S, 167°01.65’E, 17–31 m (1— MNHN IM–2000–26928); New Caledonia, Koumac, EXPÉDITION. MONTROUZIER, Stn. 1318, 20°41.4’S, 164°14.8’E, 20–30 m (5 + 14 juv. — MNHN IM–2000–26929).

Other new caledonian material examined (total 52 lots, 296 spms, including type material):

New Caledonia, EXPÉDITION MONTROUZIER, Koumac Stns. 1299 (1 spm), 1308 (3 spms), 1310 (1 spm), 1316 (5 spms), 1319 (4 spms); Touho Stns, 1259 (8 spms), 1266 (2 spms), 1269 (4 spms), 1270 (1 spm), 1271 (20 spms), 1273 (9 spms);

LAGON, Stns. 632(1 spm), 864 (2 spms), 1357 (3 spms), 1371 (1 spm), 1374 (1 spm).

Loyalty Islands, Lifou: LIFOU 2000, Stns. 1420 (8 spms), 1421 (11 spms), 1422 (2 spms), 1423 (1 spm), 1424 (1 spm), 1425 (4 spms), 1427 (2 spms), 1429 (20 spms), 1434 (14 spms), 1435 (6 spms), 1438 (1 spm), 1439 (1 spm), 1440 (1 spm), 1442 (2 spms), 1443 (1 spm), 1444 (8 spms), 1446 (5 spms), 1447 (1 spm), 1448 (3 spms), 1449 (10 spms), 1450 (18 spms), 1451 (29 spms), 1453 (9 spms), 1456 (12 spms), 1457 (14 spms), 1458 (1 spm), 1459 (3 spms), 1460 (1 spm), 1464 (6 spms), 1465 (1 spm).

Etymology. Named in honour of Virginie Héros of MNHN, for her willing assistance to the present authors and other visiting malacologists from around the world, also a participant in the Koumac and Lifou expeditions.

Distribution. Presently known from New Caledonia, 4 to ca 80 m, confirmed live to ca 50 m. The species was also collected by the SANTO 2006 expedition, Vanuatu, Aoré Island in 10– 18 m.

Diagnosis. Breadth/length 0.36–0.44, with very angular, almost pagodiform whorls, relatively short base (aperture/total length 0.24–0.37) and somewhat stiliform apex; base not indented, without fasciole; outer lip slightly alate with well-developed stromboid notch, anal sinus linguiform, with rounded apex, opening constricted by a prominent parietal tubercle. Suture not undulating, whorls adpressed to previous whorl, subsutural region broadly concave; periphery becoming progressively more angular. Axial ribs initially weak with a slight sulcus below suture, cutting off a series of weak subsutural nodules; on later whorls, axial ribs evanesce in subsutural concavity, below midwhorl bearing prominent, outwardly directed, spinose angles, those on last whorl often directed slightly anteriorly; ribs on last whorl ending at rostrum, slopingly flattened below periphery, where form a second, weak basal angle; 9–11 ribs on penultimate whorl. Rostrum with 6–7 rounded spiral ridges. Microsculpture of extremely fine collabral threads and even finer spiral ones, latter dominant on subsutural slope. White with a deep orange-brown zone around middle of last whorl, and axial blotches and flames of the same; axial ribs with 2–3 rows of whitish dashes or dots; back of lip with 2–3 orange-brown spiral bands, aperture and parietal tubercle whitish. Length to 12.3 mm.

Description. Shell clavate-fusiform, breadth/length 0.36–0.44, with very angular, almost pagodiform whorls, relatively short base (aperture/total length 0.24–0.37) and somewhat stiliform apex. Base of last whorl rapidly tapering, without fasciole, tip slightly obliquely truncate, not indented; aperture widest posterior to median, contracted at anterior end; outer lip slightly alate below anal sinus, in side view strongly convex, with welldeveloped stromboid notch, anal sinus linguiform, with rounded apex situated on lower part of subsutural concavity, sinus directed slightly adapically, constricted by the prominent parietal tubercle.

Suture shallow, not undulating, whorls adpressed to previous whorl at suture, forming a broad, sloping concavity; lower 0.6 whorl gently convex on first teleoconch whorl, periphery becoming progressively more angular, ribs on later whorls bearing prominent, outwardly directed angles below midwhorl, those on last whorl often directed slightly anteriorly; last whorl with slopingly flattened sides, forming a weak, second angle at level of parietal nodule. First teleoconch whorl with weak axial ribs, the first two whorls with a slight sulcus at about 0.3 whorl below suture, cutting off a series of weak subsutural nodules, thereafter subsuturally concave. On adult whorls, axial ribs evanesce above angle, becoming weak on base, ending at rostrum, in t/s acutely angular, leading face slightly concave, ribs subequal to intervals, 9–11 on penultimate whorl. Terminal varix towards outer lip, hump-like. Spiral sculpture restricted to rostrum, where 6–7 rounded spiral ridges. Microsculpture of extremely fine collabral threads and even finer spiral ones, the latter dominant on the subsutural slope.

Vividly patterned with deep orange-brown on brownish-white, apex and base of last whorl pure white, the orange-brown areas forming a broad band around the middle of last whorl and a series of flames on spire whorls; crests of axial ribs bear 2–3 rows of transversely oblong dots of off-white, upper row on peripheral angle, lower row sometimes merging with white base; back of lip with 2–3 orange-brown spiral bands, aperture and parietal tubercle whitish.

Protoconch cylindriform, of 2.75 nearly smooth whorls, except row of micropustules along adapical suture and scattered ones on the surface. Posteriormost 1/4 of whorl with fine incremental slightly arcuate lines. Diameter about 680 Μm, height about 730 Μm. Protoconch-teleoconch transition distinct, marked by thin but distinct axial riblet in the shape of anal sinus and appearance of strong axial definitive rib.

Measurements. 10.4 x 4.4 mm (holotype); largest and smallest paratypes: 12.3 x 4.6 mm, 8.7 x 3.5 mm.

Radula ( Fig. 18 A, B): Rachidian narrow, length more than three times exceeds width, anterior edge pointed, with large median cusp and fine side denticles (seen on some teeth only). Lateral teeth broad, arcuate, with 14 cusps, 3rd–6th from inner side being the longest and gradually diminishing in length towards outer side, where they evanesce. Marginal teeth relatively short and broad, with large blade. On anterior edge of the tooth blade constitutes 2/3 of teeth length, on posterior edge more than 1/3 of tooth length. Blade edges thickened. Accessory limb weak. About 25 rows of teeth.

Remarks. In colouration Clavus virginieae is similar to Clavus formosus (Reeve, 1846) , but differs in its spinose-pagodiform spire, caused by the axial ribs bearing sharply angular projections (varying slightly in degree of projection), and in its much finer microsculpture, deeper stromboid notch, shorter base and flatter-sided protoconch. In possessing angles to the ribs it somewhat resembles C. laetus , but in the latter these are markedly hooked adapically and the vivid orange-brown blotching of virginieae is lacking.

Figures

FIGURE 17. Clavus virginieae n. sp. A, B. Holotype; C. Largest paratype, MNHN IM – 2000 – 26925, 12.5 mm; D. Radula voucher Loyalty Islands, Lifou, LIFOU 2000, Stn. 1429, SL 10.3 mm (radula—Fig. 18 C, D); E. Molecular voucher IM – 2007 – 42549, Vanuatu, Aore Is., SANTO 2006, Stn. DB 12, 15 ° 36.6 ' S 167 ° 10.1 ' E, 10 – 18 m, SL 11.1 mm; F, G. Protoconch, Loyalty Islands, Lifou, LIFOU 2000, Stn. 1456, SL 2.4 mm.

FIGURE 18. Radulae of Clavus virginieae n. sp., C. picoides n. sp. and C. squamiferus n. sp. A, B. Clavus virginieae, Lifou, LIFOU 2000, Stn. 1429, SL 10.3 mm (shell—Fig. 17 D); C, D. Clavus picoides, Loyalty Islands, Lifou, LIFOU 2000, Stn. 1453, SL 14.0 mm (shell—Fig. 20 D); E, F. Clavus squamiferus, Paratype, Radula voucher, MNHN IM – 2000 – 26935, New Caledonia, EXPÉDITION MONTROUZIER, Touho Stn. 1273, SL 11.5 mm (shell—Fig. 21 H).