Clavus albotuberculatus (Schepman, 1889) Schepman, 1889

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 : 19-21

Clavus albotuberculatus (Schepman, 1889) , new combination

( Figs. 7 C, D, 8 A–D)

Drillia (Clavus) albotuberculatus Schepman 1889: 239 –240, text fig.

Clavus viduus (in part non Reeve, 1845); Cernohorsky 1978: pl. 54, fig. 7 only.

Tylotia nigrozonata (sensu auct., non Pleurotoma (Clavus) nigrozonata Weinkauff & Kobelt, 1876); Matsukuma et al. 1991: 183, Pl. CXXI, fig. 4.

Type data. Holotype RMNH – 122139, 42.1 x 20 mm, locality unknown ( Fig. 8 A, B). New caledonian material examined. Atoll de Surprise, LAGON Stn. 445 (1 spm). Distribution. New Caledonia, Philippines, 10 to ca 200 m (uncomfirmed record from Philippine fishermen), in New Caledonia at 40 m.

Description. Shell large and very thick, claviform with base bent strongly to right, adult length to 57 mm, breadth/length 0.46, aperture/total length 0.74; suture crenulated on early whorls, very shallow and not recessed anteriorly, subsutural region impressed and rising high up previous whorl; whorls very strongly convex; base broad, moderately indented, fasciole strong. Outer lip with strongly crenulate edge (anteriorly dentate), anal sinus a widely open, asymmetrical “U”, parietal tubercle large; stromboid notch deep.

No subsutural cord or sulcus. Axial ribs prosocline, suture to suture on early whorls, on later ones evanescing rapidly at subsutural concavity and at level of suture on last whorl, in t/s strongly rounded, slightly asymmetrical, wider than intervals, 8 on penultimate whorl. Base of last whorl with about 11 strong nodules at parietal level. Terminal varix well behind lip. Spiral sculpture of rounded ridges, confined to region of axial ribs, back of outer lip and to base of last whorl; ribs crossed by 6–7 ill-defined ridges, weak to obsolete in intervals, with very faint intermediary threads; folds on outer lip formed by low, undulant cords with finer intermediary threads; base of last whorl with very fine, low spiral ridges, fasciole with 5 coarse, angular ridges. Surface covered with dense, microscopic spiral threads, crenulating coarser collabral ones.

Dull reddish-brown with axial ribs and basal nodules whitish, columella with a diffuse orange-brown blotch at each end, also tinting anal sinus, and two diffuse bands at base of outer lip; interior of aperture white.

Measurements. 56.5 x 26.3 mm, AL 20 mm.

Radula ( Fig. 7 C, D): Rachidian relatively broad, width exceeding length, shallowly notched anteriorly, with strong median cusp and fine side denticles. Lateral teeth broad, arcuate, with 25 cusps, 6th–10th from inner side being the longest and gradually diminishing in length towards outer side, where they evanesce. Marginal teeth relatively short and broad, blade broad and long, on anterior edge of the tooth blade constitutes 2/3 of teeth length, on posterior edge slightly less than ½ of tooth length, forming well pronounced angles with major limb. Blade edges strongly thickened. Accessory limb weak. About 35 rows of teeth.

Remarks. The species was illustrated by Cernohorsky (1978) as a “Large, senile specimen” of the vidua form of Clavus unizonalis , nevertheless it differs widely from that in shape, in its extremely convex whorls, distinct spiral sculpture, strong basal tubercles and in other characters. The original description of Schepman was obliously missed by turrid scholars, since the name never appeared in literature since original publication. It was also recovered by Guido Poppe and correctly used on his site www.conchology.be (http://www.conchology.be/?t=66&family= DRILLIIDAE &species= Clavus %20 albotuberculatus , last accessed 23.01.2014). Here it is used for the first time in literature in current binomen. Very rare in New Caledonia (single specimen in 40 m), it appears to be more common in the Philippines, in 10–180 m (according to the www.conchology.be), although the lower bathymetric limit needs confirmation.

Figures

FIGURE 7. Radulae of Clavus unizonalis, C. albotuberculatus, C. protentus and C. delphineae. A, B. Clavus unizonalis, Loyalty Islands, Lifou, LIFOU 2000, Stn. 1424, SL 20.1 (shell—Fig. 6 D); C, D. Clavus albotuberculatus, LAGON, Stn. 445, SL 56.8 mm (shell—Fig. 8 C, D); E, F. Clavus protentus, Loyalty Islands, Lifou, LIFOU 2000, Stn. 1433, SL 13.5 mm (shell—Fig. 9 G); G, H. Clavus delphineae, Loyalty Islands, Lifou, LIFOU 2000, Stn. 1422, SL 10.1 mm (shell—Fig. 10 E).

FIGURE 8. Clavus albotuberculatus. A, B. Holotype of Drillia albotuberculata Schepman, 1889, RMNH. MOL. 122139, Locality unknown, 42.1 x 18.3 mm; C, D. Radula voucher, LAGON, Stn. 445, 18 º 18 ’ S, 163 º 02 ’ E, 41 m, Surprise Atoll, 56.8 x 26.3 mm (radula—Fig. 7 C, D).