Clavus canalicularis ( Röding, 1798 ), Roding, 1798

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 : 6-9

Clavus canalicularis ( Röding, 1798)

( Figs. 1 A–K, 2 A–D)

Strombus canalicularis Röding 1798: 100 (cites Strombus lividus Gmelin, 1791 , and Chemnitz 1786: pl. 136, Figs. 1269–1270). Type loc.: not given.

Clavatula auriculifera Lamarck, 1816 : p. 9, pl. 439, figs 10a–b. Type loc.: not given.

Other references. Clavus canicularis [sic]; Powell 1966: text–fig. D84 (radula), pl. 10, fig. 18; Cernohorsky 1972: 185, pl. 53, fig. 13; Higo et al. 1999: 298; Sysoev in Poppe 2008: pl. 673, figs. 9–12.

Clavus canalicularis ; Wells 1991: 7, pl. 2, figs. 7–8, 9 (syntype); Wilson 1994: 184, pl. 40, fig. 1.

Clavus (Tylotia) canicularis ; Hasegawa et al. 2000: 621, pl. 309, fig, 13.

Drillia (Clavus) auriculifera ; Bouge & Dautzenberg 1914: 135.

Tylotia auriculifera ; Habe 1970: 120, pl. 38, fig. 15.

Type data. Strombus canalicularis : types not traced, locality not given. Clavatula auriculifera : two syntypes MHNG 1097/48/1–2 ( Y. Finet, pers comm.), locality unknown.

New caledonian material examined (total 106 lots, 268 spms):

New Caledonia: EXPÉDITION MONTROUZIER: Koumac Stns. 1277 (8 spms), 1278 (1 spm), 1286 (1 spm), 1287 (1 spm), 1292 (1 spm), 1297 (2 spms), 1299 (3 spms), 1301 (1 spm), 1304 (1 spm), 1307 (2 spm), 1308 (2 spms), 1319 (2 spms), 1322 (2 spms),

Touho Stns. 1237 (12 spms), 1238 (2 spms), 1240 (11 spms), 1241 (2 spms), 1242 (50 spms), 1246 (1 spm), 1253 (11 spms), 1255 (1 spm), 1264 (1 spm), 1271(1 spm);

Nouméa: Campagne d'essais 1987, Stns. DE 02 (1 spm), DE 34 (1 spm), DE 45 (1 spm), DE 46 (2 spms);

LAGON: Stns. 4 (1 spm), 19 (1 spm), 51 (1 spm), 62 (2 spms); 80 (1 spm), 95 (5 spms), 99 (2 spms), 131 (1 spm), 233 (1 spm), 253 (1 spm), 285 (1 spm), 289 (3 spms), 294 (1 spm), 433 (1 spm), 443 (1 spm), 445 (1 spm), 483 (1 spm), 545 (1 spm), 754 (1 spm), 766 (1 spm), 859 (2 spms), 916 (1 spm), 921 (2 spms), 932 (1 spm), 941 (1 spm), 948 (2 spms), 962 (1 spm), 982 (1 spm), 995 (1 spm), 1010 (1 spm), 1017 (1 spm), 1032 (2 spms), 1126 (1 spm), 1334 (6 spms), 1338 (5 spms), 1347 (3 spm), 1355 (4 spms), 1356 (1 spm), 1358 (1 spm), 1368 (3 spm), 1370 (1 spm);

Loyalty Islands, Lifou: LIFOU 2000, Stns. 1417 (1 spm), 1419 (8 spm), 1424 (1 spm), 1427 (1 spm), 1431 (1 spm);

PLOUVEAL, Stns. 1221 (3 spms), 1222 (4 spms), 1224 (1 spm), 1225 (1 spm), 1227 (2 spm), 1228 (1 spm), 1230 (1 spm);

Coral Sea, Chesterfield Plateau: CHALCAL, Stn. D19 (1 spm), D26 (1 spm) D41 (1 spm); CORAIL 2 Stns. DW34(1 spm), DW38 (1 spm), DW43 (1 spm), DW44 (1 spm), DW51 (1 spm), DW77 (3 spms), DW100 (1 spm), DW104 (1 spm), DW107 (1 spm), Stn. DW119 (1 spm), DW122 (1 spm), DW126 (1 spm), DW139 (1 spm), DW145 (1 spm), DW146 (1 spm), DW152 (2 spms), DW156 (1 spm), DW157 (1 spm), DW164 (1 spm).

Distribution. Fiji and southern Japan to Indonesia, Queensland and New Caledonia, west to N.W. India, In New Caledonia low tide to ca 70 m (32–67 m on Plateau des Chesterfield), usually in sand or sandy gravel among rocks or coral, in our material confirmed live specimens collected to ca 30 m.

Description. Biconic-claviform or broadly claviform with orthoconoid spire (breadth/length ratio varies greatly because of varying lengths of spines), and relatively wide aperture (aperture/total length 0.42–0.50). Teleoconch of six to 7.5 strongly shouldered whorls, subsutural region concave, adpressed to base of previous whorl. Suture narrowly undercutting succeeding whorl, irregularly undulating. Early spire whorls sculptured by wide axial folds forming nodules or sharp projections on peripheries; late 3–4 whorls with strong squamiform, sometimes nearly enclosed spines directed outwardly on peripheries, especially long on penultimate and last whorls. Shell base usually with single row of low, rounded nodules. Spiral sculpture indistinct on spire whorls; last whorl with rugose, sometimes gemmate cords, on parietal region; fasciole with 6–7 low rounded declivous cords. Axial sculpture of dense growths lines, forming sharp ridges in some specimens.

Aperture wide, anal sinus openly U-shaped, directed adapically, or V-shaped in immature shells. Parietal nodule large, stromboid notch distinct. Inner aperture lip heavily calloused, sometimes false umbilicus presents.

White, cream or uniformly pale, usually with a broad deep orange-brown zone at mid-last whorl. Protoconch dark yellowish-brown, contrasting with the white teleoconch whorls that follow.

Protoconch ( Fig. 1 K) narrowly domed, of about 1.75 smooth evenly convex whorls, diameter about 750 Μm, height about 630 Μm. Protoconch-teleoconch transition indistinct, marked by weak arcuate axial rib. Protoconch in most specimens examined worn or missing.

Measurements. Largest studied specimen attains 48 mm length.

Radula ( Fig. 2 A–D): Rachidian broad, oval, with strong median cusp and fine side dentacles. Lateral teeth broad, arcuate, with 18–19 cusps, 5th–9th from inner side being the longest and gradually diminishing in length towards outer side, where they evanesce. Marginal teeth rather long, with broader short blade, being slightly over ¼ of teeth length. Blade edges thickened. Accessory limb not pronounced. About 40 rows of teeth.

Remarks. This well-known Indo-West Pacific species was first recorded from New Caledonia by Bouge & Dautzenberg (1914); Wells (1991) gave several modern records from this region.

The only other New Caledonian species with similar (if weaker) spines is Clavus rugizonatus Hervier, 1896 , which differs in bearing dense spiral rows of pustules, often diagonally aligned, on its base, and usually by the vivid orange-brown tint of its colour band. New Caledonian specimens of C. canalicularis usually have only a row of rounded tubercles around the middle of the base, and are white with a dark brown to dark greyish brown zone around the middle of the last whorl (rarely with a brown subsutural line). In colour pattern they resemble Clavus unizonalis ( Lamarck, 1822) , which, however, has a dark columella and lacks the spines. Among individuals of C. canalicularis , degree of development of individual spines varies, rendering breadth/length ratios almost meaningless.

Figures

FIGURE 1. Clavus canalicularis (Röding, 1798). A. Type figures of Strombus canalicularis Röding, 1798, after Chemnitz 1786: pl. 136, figs 1269 – 1270; B. Syntype of Pleurotoma auriculifera Lamarck, 1822, MHNG 1097 / 48 / 2, SL 48.2 mm; C, D. New Caledonia, Noumea Sector, Stn. 1347, SL 31.2 mm; E. Coral Sea CHALCAL 1, Stn. D 26, SL 17.3 mm; F. Molecular voucher IM – 2007 – 42345, Philippines, Pamilacan Is, Expedition PANGLAO 2004 Stn. B 11, 9 ° 29.4 ' N 123 ° 56.0 ' E, 2 – 4 m, SL 18.8 mm; G. Molecular voucher IM – 2007 – 42547, Vanuatu, Aore Is., SANTO 2006 Stn. DS 10, 15 ° 36.6 ' S 167 ° 10.1 ' E, 6 – 24 m, SL 23.4 mm; H. Radula voucher, LAGON, Stn. 289, Noumea Sector, SL 22.8 mm (radula—Fig. 2 C – D); I, J. LAGON Stn. 545, Grand Récif Sud, SL 30.8 mm; K. Protoconch, EXPÉDITION MONTROUZIER, Koumac Stn. 1307.

FIGURE 2. Radulae of Clavus canalicularis, C. exasperatus and C. boucheti. A – D. Clavus canalicularis A, B. EXPÉDITION MONTROUZIER, Koumac, Stn. 1277, SL 30.5 mm; C, D. LAGON, Nouméa Sector, Stn. 289, SL 22.8 mm (shell—Fig. 1 H); E, F. Clavus exasperatus, Loyalty Islands, Lifou, LIFOU 2000, Stn. 1420, SL 25.9 mm (shell—Fig. 4 H); G, H. Clavus boucheti, New Caledonia, LAGON, Grand Recif Sud, Stn. 305, SL 24.5 mm (shell—Fig. 5 F).