Clavus picoides, 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 : 40-41

Clavus picoides new species

( Figs. 18 C, D, 20 A–D)

Type material. Holotype: New Caledonia, LAGON, Nouméa Sector, Grand Récif Aboré outer slope, Stn. 1352, 22°22.2’S, 166°16.0– 166°16.1’E, 27–35 m, MNHN IM–2000–26930; Paratypes: New Caledonia, Touho, EXPÉDITION MONTROUZIER, Stn. 1269, 20°35.1’S, 165°08.1’E, 15–20 m (4— MNHN IM–2000–26931).

Other new caledonian material examined (total 14 lots, 28 spms, including type material):

New Caledonia, EXPÉDITION MONTROUZIER, Touho Stns. 1270 (3 spms), 1271 (1 spm), 1272 (3 spms), 1273 (1 spm).

Loyalty Islands, Lifou: LIFOU 2000, Stns. 1410 (1 spm), 1432 (5 spms), 1434 (2 spms), 1435 (2 spms), 1445 (2 spms), 1453 (1 spm), 1454 (1 spm), 1457 (1 spm).

Etymology. pica + oides (resembling Clavus pica, Greek noun)

Distribution. Apparently endemic to New Caledonia and Loyalty Islands, alive in 2– 35 m.

Diagnosis. Breadth/length 0.33–0.44, aperture/total 0.40–0.46, whorls slightly convex, with a gently concave sulcus above midline, periphery submedian, slightly rounded, base relatively broad, fasciole barely developed or absent, base of siphonal canal truncate, not indented. Anal U-shaped sinus not markedly constricted, stromboid notch very slight. Axial ribs rather weak, suture-to-suture, on penultimate whorl indented by a wide, shallow sulcus above periphery, equal in width to their intervals, 14–17 on penultimate whorl, anteriorly reaching the rostral lirae; axial ribs slightly sinuous and indented towards their base; last whorl terminal varix ca 0.20 whorl behind lip, broad, rounded; intervals between ribs with only faint indications of spiral striae. Rostrum with five rounded spiral ridges. Protoconch papillose-conic, ca 2.2 whorls, breadth 0.70 mm. Off-white, with diffuse orange-brown axial streaks or blotches; on last whorl these form a broad median zone, plus 1–2 faint rows of dots on upper half of each whorl, and a row of faint brown streaks on base. Attains 10.2 mm.

Description. Narrowly claviform (breadth/length 0.33–0.44, aperture/total length 0.40–0.46), spire somewhat orthoconoid, moderately blunt, whorls weakly convex, with a gently concave sulcus above midline, periphery submedian, slightly rounded; suture straight, base relatively broad, fasciole weak to distinctly convex, base of siphonal canal truncate, not indented, siphonal canal wide. Outer lip strongly convex, with a very slight stromboid notch; anal sinus U-shaped, not markedly constricted, slightly adapically directed.

Axial ribs rather weak, suture-to-suture, except on fifth (penultimate) whorl, where they are indented or slightly interrupted by a wide, shallow sulcus above periphery, opisthocline, in t/s weakly angular with sloping sides, equal in width to their intervals, about 12 on first teleoconch whorl, 14–17 on penultimate whorl, anteriorly reaching the rostral lirae; axial ribs slightly sinuous and indented towards their base; last whorl with a broad, rounded terminal varix ca 0.20 whorl behind lip; intervals between ribs with very fine collabral threads and faint indications of spiral striae. Base with five low, rounded spiral ridges on rostrum.

Protoconch (holotype) papillose-conic, apex rounded, consists of about two smooth whorls, diameter ca 900 µm, height 780 µm.

Off-white, with diffuse orange-brown axial streaks or blotches; on last whorl these evanesce subsuturally, forming a broad median zone, plus 1–2 faint spiral rows of dots on upper half of each whorl, and a row of faint brown streaks on base. Protoconch and aperture white. Attains 10.2 mm.

Measurements. 8.7 x 3.8 mm (holotype); 10.2 x 3.4 mm (paratype).

Radula ( Fig. 18 C, D): Rachidian narrow, length exceeds width, anterior edge rounded. Teeth with strong median cusp and fine side denticles that are shorter than tooth base. Posterior edge of tooth base of irregular shape. Lateral teeth broad, arcuate, with 13 cusps, 3rd–6th from inner side being the longest and gradually diminishing in length towards outer side, where they evanesce. Marginal teeth long and narrow, with broader distinct short blade, about 1/3 of tooth length. Accessory limb weak. About 25 rows of teeth.

Remarks. Although similar to Clavus pica , this species is narrower, with flatter whorls (with only a slight indication of a subsutural concavity), 14–17 straighter axial ribs on the penultimate whorl (instead of 18–21), and no sign of the characteristic brown spiral lines, although both taxa show similar irregularly spaced brown blotches. Unfortunately all available specimens, except the holotype, are juvenile, worn, or deformed by major crab-attack scars. Compared with Clavus moquineanus , C. picoides is less biconical, and has fewer axial ribs and weaker spiral microsculpture.

Figures

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).