Turridrupa albofasciata (E. A. Smith, 1877)

(Figs. 15 A–J, 22 D)

Pleurotoma albofasciata E. A. Smith, 1877: 491 . Type loc.: Sandwich Islands (Hawaii).

Turridrupa albofasciata; Powell, 1967: 416, pl. 303, fig. 3–4; Cernohorsky, 1978: 151, pl. 54, fig. 3; Kay 1979: 338, figs. 111J, 113H; Wilson, 1994: 195; Severns, 2011: 384, fig. 2.

Surcula gatchensis Hervier, 1896: 144; Hervier, 1896: 61, pl. 1, fig. 7. Type loc.: Gatcha Bay, Lifou Island. [= T. albofasciata f. Powell, 1966; 1967].

Surcula bijubata var. gatchensis; Bouge & Dautzenberg, 1914: 145.

Turridrupa gatchensis; Oyama & Takemura, 1960: figs 6-8.

Type material

HOLOTYPE: 21.0 mm (NHMUK 1963781, Figs. 15 A–C).

SYNTYPES of Surcula gatchensis: originally 6 syntypes, one in MNHN (MNHN-IM-2000-2946; Figs . 15 D–F), some possibly in IRSN and AMS.

Sequenced material

PAPUA NEW GUINEA: KAVIENG 2014: Stn KS21 (MNHN-IM-2013-50764)—Stn KZ02 (MNHN-IM-2013- 53418)—Stn KZ03 (MNHN-IM-2013-51290)—PAPUA NIUGINI: Stn PS 11 (MNHN-IM-2013-12713)—Stn PS 23 (MNHN-IM-2013-14953).— VANUATU: SANTO 2006: Stn DB86 (MNHN-IM-2007-41191).

Material examined

PHILIPPINES: PANGLAO 2004: Stn S12, 1 spm (MNHN-IM-2014-663).— MARSHALL ISLANDS: 1 spm, Kwajalein Atoll, 20 m on sand, coll. by B. Cook, 1993 (PS- 1037).— VANUATU: SANTO 2006: StnDB29, 1 spm (MNHN-IM-2014-662).— NEW CALEDONIA: MONTROUZIER: Stn 1271, 8 spms (MNHN-IM-2014-657)— Stn 1272, 1 spm (MNHN-IM-2014-658)—Stn 1310, 1 spm (MNHN-IM-2014-659)—Stn 1312, 1 spm (MNHN- IM-2014-660)—Stn 1339, 1 spm (MNHN-IM-2014-661)—LIFOU 2000: Stn 1420, 1 spm (MNHN-IM-2014- 653)—Stn 1429, 1 spm (MNHN-IM-2014-654)—Stn 1448, 2 spms (MNHN-IM-2014-655)—Stn 1457, 3 spms (MNHN-IM-2014-656).— HAWAII: Maui, off Maalaea, 1–9 m (UF 416623)—1 spm, Hawaii Island, Puako Bay, 10–15 m, under dead corals, coll. by B. Cook, 1980 (PS- 208).

Distribution

The species is known from the Philippines to Hawaii, in depths between 2 to 30 m.

Description

Shell medium-sized for genus, up to 22.0 mm in height, claviform with about 7 teleoconch whorls; spire about 1.5 times the height of the aperture including siphonal canal; suture incised and inconspicuous; siphonal canal fairly short, truncated and robust, anal sinus moderately deep, U-shaped at the termination of the second spiral cord; parietal callus-pad strong and well developed; interior of lip with about 7 spiral threads; lip preceded by a low, inconspicuous varix.

Sculpture of narrow spiral cords (interspaces about 2 times wider), with sloping sides, 3 on spire whorls, occasionally increasing to 4 on whorl, sinus cord slightly stronger; sinus cord median, in some specimens slightly undulating while in other with well defined gemmules (from slightly to more distinctly), other cords may also show weak gemmules; base of last whorl with about 10 primary spiral cords; intervals between cords with 1–5 fine but well-developed spiral threads; no axial sculpture.

Protoconch eroded in all examined specimens, of approximately 3 whorls.

Colour blackish-, purplish- or reddish-brown, with a pale brown band below peripheral keel, inner lip dark reddish-brown.

Radula (Fig. 22 D) short, ~30 rows of teeth, including 5 nascent rows; length ~0.93 mm. Central formation resembles an integral tooth with rectangular base and sharp, narrow rhomboid central cusp (length/width ~6). Anterior margin of central formation indistinct. Marginal teeth ~95 µm long (1.9% AL). Major limb broad, forms distinct socket for accessory limb insertion. Major limb forms weak anterior blade, poorly differentiated from remaining tooth part. Accessory limb narrow anteriorly, gradually broadens to ~2/3 of major limb’s width. Poorly differentiated from major limb, especially along anterior margin. Length ~0.8 of major limb, reaches outer limit of major limb.

Remarks

Turridrupa albofasciata is similar to T. bijubata but differing in the slightly weaker and dark coloured spiral cords and the truncated siphonal canal (leading to a more claviform shell).

T. albofasciata specimens have been seen only from the Hawaiian Islands while material examined from New Caledonia is agreeing with Hervier’s (1896) examples of Surcula gatchensis . These are blackish-brown, instead of reddish brown, have weaker peripheral nodules and a less pupiform shape (spire more orthocline and rostrum forming a fasciole) than typical T. albofasciata . A comparison at molecular level would possibly help to decide whether they are local forms or two different species.