Limatium pagodula, Strong, Ellen E. & Bouchet, Philippe, 2018

Strong, Ellen E. & Bouchet, Philippe, 2018, A rare and unusual new bittiine genus with two new species from the South Pacific (Cerithiidae, Gastropoda), ZooKeys 758, pp. 1-18 : 4-5

Limatium pagodula sp. n. Fig. 2

Type material.

Holotype UF 427943 (Biocode No. MBIO19550, Specimen No. BMOO-03501,) (Fig. 2A, H); paratypes as listed below.

Type locality.

French Polynesia, Society Islands, Moorea. Haapiti, just NW of Matauvau Pass outer reef slope, brushed from under rubble, 17°34.1'S, 149°53.0'W, 20-22 m (Moorea Biocode; collector’s event ID MIB_087; leg. Chris Meyer & Christian McKeon; 20 October 2008).

Other material examined.

FRENCH POLYNESIA. SOCIETY IS: Tahiti, grotte du chenal d’Arue, ca. 17°31'S, 149°31.3'W, 12 m, 1 empty shell (dd), USNM 1462729 ex coll. Letourneux (Fig. 2E); Tahiti, faille d’Arue, 33 m, 1 dd, USNM 1462730 ex coll. Letourneux. TUAMOTU IS: Makemo, secteur de Pohue, 16°40.1'S, 143°22.5'W, 63 m, 1 dd, paratype USNM 1462731 ex coll. Letourneux (Fig. 2B); Makemo, passe Arikitamiro, ca. 16°37.1'S, 143°33.9'W, 45-54 m, 9 dd in coll. Letourneux (Fig. 2D, F; 6 not seen); Rangiroa, passe de Tiputa, ca. 14°58.0'S, 147°37.5'W, 100 m, 2 dd in coll. Letourneux (not seen). VANUATU. SANTO I.: SANTO 2006: stn. ZB9, W. Malo I., 15°40.6'S, 167°05.1'E, 5-7 m, 1 dd, MNHN uncatalogued. - Stn. DS104, W. of Tutuba I., Vunatavoa Bay, 15°34.1'S, 167°16'E, 10-80 m, 1 dd, paratype MNHN IM-2014-6933 (Fig. 2C).

Etymology.

From the Latin pagoda, with reference to the strongly angular whorls reminiscent of the upward curving roofs of Asian temples; pagodula is a diminutive, used as a noun in apposition.

Diagnosis.

Shell [holotype, unless otherwise noted]. Shell narrow, slender, with high, conical spire, body whorl occupying ~45% of shell height, consisting of 9+ [first three whorls very encrusted] moderately convex but angular teleoconch whorls, suture impressed (Fig. 2A). Protoconch [very worn on holotype; description based on specimens illustrated in Fig. 2 E–G] multispiral, of 2.5 whorls, with a sculpture of two strong, pustulose spiral keels at periphery, and a third, much lighter cord on the base, essentially covered by next whorl; strong, prosocline, axial riblets on sutural ramp, fading out abapically towards spiral keel; and irregular, elongated granules that cover the abapical part of the whorl and extend in between the two peripheral keels; protoconch/teleoconch transition sharp, with a lamellar terminal varix and a deeply indented sinusigera notch (Fig. 2 E–G). Sculpture of teleoconch consisting of broad, poorly defined axial ribs forming a strong angular projection at adapical two-thirds of the whorl, crossed over by three (on body whorl 4) narrow, sharply defined spiral cords on exposed part of adult whorls, and a 4th, strongly raised, basal cord that is mostly covered by next whorl. Shell base slightly concave, with 7 unevenly spaced spiral cords. Siphonal canal very short, broadly open, constricted. Aperture circular-ovate, ~30% of shell height (in paratype, flaring and subquadrate, forming an angle where basal cord meets the outer lip). Anal canal indistinct. Columella concave with thinly callused columellar lip. Outer lip of aperture forming a terminal varix, subvertical on periphery, regularly convex on base. Shell surface smooth and shiny, as if waxed, color overall deep brown with broad, opaque white fascioles extending from suture to suture at irregular intervals, spiral cords on spire and base white, cord encircling the base brown with white blotches at regular intervals; columellar side of canal and columellar callosity white, parietal callosity transparent. Tip of teleoconch (first 1.5 whorl) white, protoconch dark brown. Dimensions: 6.50 × 2.65 mm. Average 5.98 ± 0.48 mm (n = 3).

External anatomy. Head-foot dark golden brown in color; cephalic tentacles with irregular white blotches and golden tips. Foot sole golden, with thin, transverse white lines, discontinuous across prominent longitudinal groove at midline; condition of pedal glands unknown. Epipodial skirt also with thin, transverse white to golden lines, present from propodium to large, projecting opercular lobe. Epipodial tentacles lacking.

Radula. The radula of the sequenced specimen was teratological, and we do not provide a detailed description or illustration. The gross features that were visible conform to those in L. aureum sp. n. (see below): a rachidian with broad hexagonal basal plate and elevated central portion with rounded base, cutting edge with three pointed cusps, lateral teeth with short lateral extensions roughly 1.5 times length of cutting edge, face of lateral teeth with buttress terminating in prominent, rounded knob midway down face of lateral teeth, outer edges of outer marginal teeth acuspate.

Distribution and ecology.

Society Islands and Tuamotus (French Polynesia); Vanuatu. Known only from the material examined. Only one specimen was collected alive, from the outer reef slope, brushed from under rubble, 20-22 m.

Remarks.

The sequenced specimen from Moorea is designated as holotype, although its outer lip is not fully mature. In the fully adult paratype from Santo (Fig. 2C), the axial white fascioles are fewer, but are aligned from one whorl to the next, and there is a strong varix one-half whorl before the aperture.