Turridrupa jubata (Reeve, 1843)

(Figs. 4 A–M, 21 C–D)

Pleurotoma jubata Reeve, 1843 (March): pl. 7, sp. 52; Hinds 1843 (October): 37; Hinds 1844: 15, pl. 5, fig. 3. Type loc.: China Sea and Straits of Malacca, 18 fath, mud.

Pleurotoma (Hemipleurotoma) jubata; Schepman 1913: 36 (400).

Turridrupa jubata; Oyama & Takemura 1960: figs. 9, 10; Powell 1967: 423, pl. 301, fig. 3; Cernohorsky 1978: 150, pl. 53, fig. 10; Cernohorsky 1980: 124, fig. 33.

Pleurotoma rimata Preston, 1908 (non Pleurotoma (Drillia) rimata E. A. Smith, 1888): 190, pl. 17, fig. 62. Type loc.: Andaman Islands.

Turridrupa prestoni Powell, 1967: 423, pl. 301, fig. 4 (substitute name for P. rimata; new synonym).

Type material

Probable SYNTYPE of Pleurotoma jubata, 32.4 mm (NHMUK 1854.4.10.37; Figs. 4 A–C).

HOLOTYPE of Pleurotoma rimata, 23.5 mm, (ZSI M4001 /1; Figs. 4 I–J).

Sequenced material

NEW CALEDONIA: KOUMAC 2.1: Stn KR624 (MNHN-IM-2013-81399)—Stn KR625, (MNHN-IM-2013- 85107; MNHN-IM-2013-85108; MNHN-IM-2013-85109; MNHN-IM-2013-85110)—Stn KR634 (MNHN-IM-2013-84498).—KOUMAC 2.3: Stn KR1035 (MNHN-IM-2019-8424)—Stn KR1005 (MNHN- 2019-2618).

Material examined

TANZANIA: Zanzibar, Bawi Island, 5–8 fms, 1 spm (ANSP 226560)— Zanzibar, Pwakuu Island, 11–18 fms,1 spm (ANSP 213774).— MADAGASCAR: Nosy Iranja, 10 fms, 1 spm (ANSP 262282)—Nosy Tanikely, 15 fms, 1 spm (ANSP 261064).— JAPAN: off Osaka, lobster net, 1 spm (PS- 1071).— PHILIPPINES: PANGLAO 2004: Stn T11, 1 spm (MNHN-IM-2014-188)— Cebu, Sogod, 30–100 m, by tangle net 2 spms (MNHN-IM-2014-731, PS- 1064)— Mindanao, Balut Island, Tinina, 100–200 m, by tangle net, 1 spm (PS- 1059).— MICRONESIA: Palau, Kossol Passage, 15–20 fms, 1 spm (ANSP 201836).— NEW CALEDONIA: LAGON: Stn DW13, 1 spm (MNHN-IM-2014-217)—Stn DW16, 2 spms (MNHN-IM-2014-584)—Stn DW25, 1 spm, (MNHN-IM-2014-579)—Stn DW32, 3 spms (MNHN-IM-2014-229)—Stn DW69, 3 spms (MNHN-IM-2014-595)—Stn DW87, 3 spms (MNHN-IM-2014-243)—Stn DW89, 2 spms (MNHN-IM-2014-245)—Stn DW91, 1 spm (MNHN-IM-2014-250)—Stn DW116, 1 spm (MNHN-IM-2014-216)—Stn DW131, 4 spms (MNHN-IM-2014-593)—Stn DW133, 9 spms (MNHN-IM-2014-218)—Stn DW143, 2 spms (MNHN-IM-2014-219)—Stn DW146, 3 spms (MNHN-IM-2014-574)—Stn DW154, 3 spms (MNHN-IM-2014-594)—Stn DW192, 2 spms (MNHN-IM-2014-590)—Stn DW230, 1 spm (MNHN-IM-2014-220)—Stn DW232, 2 spms (MNHN-IM-2014-585)—Stn DW247, 1 spm (MNHN-IM-2014- 221)—Stn DW251, 1 spm (MNHN-IM-2014-222)—Stn DW272, 1 spm (MNHN-IM-2014-223)—Stn DW273, 1 spm (MNHN-IM-2014-224)—Stn DW279, 1 spm (MNHN-IM-2014-580)—Stn DW287, 3 spms (MNHN-IM-2014- 577)—Stn DW289, 2 spms (MNHN-IM-2014-225)—Stn DW298, 8 spms (MNHN-IM-2014-573)—Stn DW299, 5 spms (MNHN-IM-2014-226)—Stn DW301, 1 spm (MNHN-IM-2014-227)—Stn DW319, 1 spm (MNHN-IM-2014-228)—Stn DW322, 4 spms (MNHN-IM-2014-230)—Stn DW346, 3 spms (MNHN-IM-2014-591)—Stn DW347, 2 spms (MNHN-IM-2014-231)—Stn DW348, 2 spms (MNHN-IM-2014-232)—Stn DW349, 1 spm (MNHN-IM-2014-233)—Stn DW350, 2 spms (MNHN-IM-2014-234)—Stn DW553, 6 spms (MNHN-IM-2014- 586)—Stn DW565, 5 spms (MNHN-IM-2014-596)—Stn DW570, 2 spms (MNHN-IM-2014-583)—Stn DW572, 8 spms (MNHN-IM-2014-588)—Stn DW582, 6 spms (MNHN-IM-2014-582)—Stn DW614, 1spm (MNHN-IM-2014-235)—Stn DW621, 1spm (MNHN-IM-2014-236)—Stn DW628, 1spm (MNHN-IM-2014-237)—Stn DW662, 1spm (MNHN-IM-2014-581)—Stn DW663, 1spm (MNHN-IM-2014-238)—Stn DW672, 1spm (MNHN-IM-2014- 239)—Stn DW694, 1spm (MNHN-IM-2014-240)—Stn DW726, 3 spms (MNHN-IM-2014-576)—Stn DW732, 2 spms (MNHN-IM-2014-241)—Stn DW737, 5 spms (MNHN-IM-2014-589)—Stn DW822, 1 spm (MNHN-IM-2014-242)—Stn DW880, 1 spm (MNHN-IM-2014-244)—Stn DW890, 2 spms (MNHN-IM-2014-246)—Stn DW892, 3 spms (MNHN-IM-2014-247)—Stn DW901, 1 spm (MNHN-IM-2014-248)—Stn DW902, 2 spms (MNHN-IM-2014-249)—Stn DW975, 1 spm (MNHN-IM-2014-592)—Stn DW980, 1 spm (MNHN-IM-2014- 251)—Stn DW997, 1 spm (MNHN-IM-2014-252)—Stn DW1006, 1 spm (MNHN-IM-2014-587)—Stn DW1020, 1 spm (MNHN-IM-2014-253)—Stn DW1021, 1 spm (MNHN-IM-2014-254)—Stn DW1043, 1 spm (MNHN-IM-2014-255)—Stn DW1045, 1 spm (MNHN-IM-2014-256)—Stn DW1068, 1 spm (MNHN-IM-2014-257)—Stn DW1235, 13 spms (MNHN-IM-2014-575).—MOUNTROUZIER: Stn 1260, 5 spms (MNHN-IM-2014-578)—Stn 1261, 4 spms (MNHN-IM-2014-258)—Stn 1269, 1 spm (MNHN-IM-2014-259)—Stn 1272, 4 spms (MNHN-IM-2014-598)—Stn 1322, 2 spms (MNHN-IM-2014-260)—Stn 1336, 18 spms (MNHN-IM-2014-599; PS- 830)—Stn 1345, 3 spms (MNHN-IM-2014-261)—Stn 1374, 1 spm (MNHN-IM-2014-262).—LIFOU 2000: Stn 1460, 2 spms (MNHN-IM-2014-597).—BATHUS 1: Stn DW641, 1 spm (MNHN-IM-2014-214)—Stn DW692, 1 spm (MNHN- IM-2014-215).—VAUBAN: Stn DL48, 5 spms (MNHN-IM-2014-263).

Distribution

So far known East Africa (Zanzibar) in the west to New Caledonia in the east.

Description

Shell large-sized for genus (up to 32.4 mm), broadly fusiform with about, with a long rostrum, its end obliquely truncate, spire orthoconoid, whorls sloping and more or less overhanging the following whorl; right side of dorsum with a wide, rounded varix; aperture trigonal, anal sinus linguiform, its border projecting conspicuously; interior of outer lip with ca. 6–8 spiral threads, inner lip usually with a thick callus, its edge somewhat free, fasciole often strong, forming a false umbilicus.

Subsutural cord with median angle, narrow, flanked on each side by a low thread; sulcus equal in width to cord, with several weak spiral threads; sinus cord narrow, typically with elongate, low, compressed gemmules, ca. 20 on penultimate whorl, but sometimes mere crenulations; lower part of penultimate whorl with an angular peripheral cord, sometimes replaced by two weaker cords, intervals with 1–5 fine intermediary threads. Base of last whorl with about 4 angular or rounded cords, separated by an irregular number of intermediary threads and ridges; rostrum with 5–8 coarse, angular threads. Microscopic spiral and collabral striae faintly visible.

Protoconch narrowly domed of about 1.5 vitreous whorls, smooth except for weak arcuate riblets at the last third whorl next to termination.

Background colour pale yellowish-brown or buff with lighter-coloured or white rostrum, spiral cords usually darker; gemmules light-brown to white; aperture white, sometimes with bluish tint.

Radula (Figs. 21 C–D) ~70 rows of teeth, including 28 nascent rows; total length ~2.2 mm. Central formation has three elements: rhombic central cusp (length/width ~3.3–4.9) and trapezoid, nearly triangular lateral elements with broad, elevated anterior margin. Lateral elements closely positioned to central cusp. Marginal teeth ~70–95 µm long (1.1–1.2% AL). Major limb moderately broad. Accessory limb narrow anteriorly, fuses with major limb’s dorsal surface, no socket. Broadens sharply or gradually, width slightly narrower or equal to major limb. Accessory limb ~0.6–0.65 length of major limb, does not protrude beyond major limb’s outer limit.

Remarks

In his monograph on Turridrupa, Powell (1967) indicated that the holotype of Turridrupa jubata could not be found in the British Museum, and that its identity was therefore uncertain. Subsequently, a probable syntype has been located and was figured by Higo et al., 2001 and is shown herein (Figs. 4 A–C). The syntype differs from the specimen depicted by Powell (Fig. 4 F) in the broader and more solid shell, a longer siphonal canal and by having larger gemmules on the sinus cord. Both “forms” are present in the examined material, but presently, only specimens agreeing with the specimen depicted by Powell have been sequenced. For the moment we consider the differences within the intraspecifc variation.

As stated above, Powell (1967) illustrated a shell that he felt fits the description of Turridrupa jubata . This illustrated specimen differs slightly from Turridrupa prestoni Powell, 1967 (substitute name for Pleurotoma rimata Preston, 1908 non Pleurotoma (Drillia) rimata E. A. Smith, 1888) by a smaller and less angulated shell. However, the probable syntype of T. jubata now available turns out to be very close to that of Pleurotoma rimata (Figs. 4 I–J) and we therefore consider T. prestoni a synonym of T. jubata .

Specimens from Zanzibar and Madagascar differ by more robust shells with slightly broader spiral cords and shorter siphonal canals (Figs. 4 K–M). Whether these specimens represent a geographical variation or an undescribed species requires additional material and needs further evaluation.