Clavus laetus (Hinds, 1843)

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 : 42

Clavus laetus (Hinds, 1843)

( Figs. 21 A–D)

Clavatula laeta Hinds 1843: 41 ; Hinds 1844: 20, pl. 6, figs. 15–16.

Other references.

Pleurotoma laeta ; Reeve 1843: pl. 18, sp. 155.

Pleurotoma (Clavus) laeta ; Weinkauff 1876: 55, pl. 12, figs. 4, 6.

Splendrillia laeta ; Powell 1966: 84; Severns 2011: 368, pl. 167, fig. 2.

Clavus laetus ; Cernohorsky 1978: 153, pl. 55, fig. 1; Wells 1991: 15, pl. 4, figs. 1–2 (syntype); Wilson 1994: 184, pl. 40, figs. 4a–b.

Clavus (Splendrillia) laeta ; Kay 1979: 346, fig. 115F.

Type data. Two syntypes NHMUK 1879.2.26.67, larger photographed (fig. 21 A). Type loc.: New Guinea and Straits of Makassar, 7–10 fath. [13–18 m].

New caledonian material examined (total 4 lots, 8 spms):

New Caledonia, LAGON, Stn. 1373 (1 spm); EXPÉDITION MONTROUZIER, Touho Stn. 1270 (1 spm).

Loyalty Islands, Lifou: LIFOU 2000, Stns. 1432 (3 spms), 1436 (2 spms), 1446 (2 spms).

Distribution. New Caledonia, Loyalty Islands, Tahiti and Hawaii to southern Japan, Indonesia and Western Australia, littoral to 36 m, under dead coral.

Description (based on New Caledonian examples): Narrowly claviform (breadth/length 0.36–0.39), spire occasionally slightly bent; base relatively broad; aperture/total length 0.32–0.34. Anal sinus linguiform to almost lacrimiform, strongly constricted by an angular peripheral nodule, which merges with outer lip; stromboid notch distinct. Axial ribs forming angles (sometimes hooked) at shoulder, somewhat continuous across whorls, opisthocline, in t/s angular, equal to intervals, 8–11 on penultimate whorl, obsolete above shoulder and at parietal level, where there is a row of secondary rib-like nodules; a hump-like terminal varix ca 0.25 whorl behind lip; faint sinuous collabral threads. No spiral sculpture except for 3–5 angular ridges on rostrum, but microscopic collabral striae are present.

Protoconch ( Fig. 21 D) nearly cylindrical, flat-topped, of two smooth whorls, posteriormost half whorl with fine incremental slightly sinuouse lines. Diameter about 740 Μm, height about 600 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.

Glossy, greyish-white with blotches of yellowish or orange, often with an interrupted row of orange-brown spots around middle of last whorl, angles of ribs and base of last whorl white.

Measurements (New Caledonian adults): 10.2 x 4.0 mm, 13.9 x 5.0 mm.

Radula. Not available.

Remarks. Only a few, mostly juvenile or damaged shells are available from New Caledonia. These may prove to have a slightly larger protoconch than the types (diameter 0.74–0.87 mm against 0.62–0.67 mm).

Figures

FIGURE 21. Clavus laetus (Hinds, 1843) (A – D) and Clavus squamiferus n. sp. (E – I). A, B. Holotype of Clavatula laeta NHMUK 1879.2. 26.67, New Guinea and Straits of Makassar, 7 – 10 fath. [13 – 18 m]; C. Loyalty Islands, Lifou, LIFOU 2000, Stn. 1446, SL 10.2 mm; D. Protoconch, New Caledonia, EXPÉDITION MONTROUZIER Touho, Stn. 1270, SL 8.5 mm; E, F. Clavus squamiferus, Holotype; G. Paratype, MNHN IM – 2000 – 26933 SL 10.2 mm; H. Paratype, Radula voucher, MNHN IM – 2000 – 26935, New Caledonia, EXPÉDITION MONTROUZIER, Touho Stn. 1273, SL 11.5 mm (radula—Fig. 18 G, H); I. Protoconch, New Caledonia, EXPÉDITION MONTROUZIER Touho, Stn. 1269, SL 3.3 mm.