Leptotrophon wareni, Houart & Héros, 2012

Houart, Roland & Héros, Virginie, 2012, New species of Muricidae (Gastropoda) and additional or noteworthy records from the western Pacific, Zoosystema 34 (1), pp. 21-37 : 32-34

Leptotrophon wareni n. sp.

( Fig. 3 A-D)

TYPE MATERIAL. — Holotype (dd) MNHN 24181 and 3 paratypes (dd) MNHN 24182–24184 .

TYPE LOCALITY. — Solomon Islands, 8°16’S, 160°40’E, 570-756 m [NO Alis, SALOMON 1: stn DW1772, Bouchet, Dayrat, Warén & Richer-IRD coll, 28/ IX /2001].

MATERIAL EXAMINED. — Solomon Islands. SALOMON 1: stn DW1772, 8°16’S, 160°40’E, 570-756 m, 1 dd, holotype MNHN 24181. — Stn DW1824, 9°49’S, 160°56’E, 298-318 m, 1 dd, paratype MNHN 24182. — Stn DW1825, 9°51’S, 160°58’E, 340-391 m, 1 dd, paratype MNHN 24183. — SALOMONBOA 3: stn DW2790, N Malaita, 8°19’S, 160°37’E, 314-586 m, 1 dd, paratype MNHN 24184.

DISTRIBUTION. — Solomon Islands, known only from the four stations listed above, empty shells in 318- 570 m.

ETYMOLOGY. — Named in honour of Anders Warén (Swedish Museum of Natural History, Stockholm), in recognition of his collaboration over many years in extracting, mounting and scanning hundreds of muricid radulae and shells for analysis of microsculpture.

DESCRIPTION

Shell medium sized for the genus, height 11.8 mm, height/width ratio 2-2.4. Slender, lanceolate, narrow, nodose. Subsutural ramp broad, strongly sloping, weakly concave. Shell entirely white.

Spire very high with 1.5 protoconch whorls ( Fig. 3D) and five angulate, narrow, shouldered, nodose whorls. Suture weakly adpressed. Protoconch large,broad,whorls rounded,smooth.Diameter(holotype) 900 µm. Terminal lip shallow, weakly curved.

Axial sculpture of teleoconch whorls consisting of low, broad, rounded varices, each with short, blunt spinelets. First teleoconch whorl with 8 or 9 varices, 2nd with 6-8, 3rd with 7 or 8, 4th and 5th (last) with 7. Spiral sculpture of low, broad primary cords. First to antepenultimate whorl with visible P1 and P2, penultimate (4th) whorl with P1, P2 and P3; P3 partially covered with following whorl. Last whorl with weakly defined IP, most conspicuous on axial varices, P1, P2, s2, P3-P6, ADP, MP, ABP, EABP1 (EABP2, EABP3) ( Fig. 3C). Spiral cords decreasing in strength and more closely spaced abapically. Intersection of axial varices and spiral cords with small, strong, blunt spinelets. P1 and P2 with strongest spines. Other spiral sculpture consisting of numerous, narrow striae.

Aperture small, ovate. Columellar lip narrow, smooth, rim adherent. Anal notch shallow, broad. Outer lip erect, smooth within. Siphonal canal short, narrow, weakly dorsally recurved, open.

Operculum and radula unknown.

REMARKS The genus Leptotrophon currently includes 28 Recent species, a majority of them (25) described from New Caledonia and neighbouring localities.One species was described from Indonesia, and another from Brazil. Leptotrophon segmentatus (Verco, 1909) ( Fig.3G, H) from South Australia is here included for the first time in Leptotrophon , based on shell morphology.

Leptotrophon wareni n. sp. can be usefully compared with only three species: L. segmentatus , L. coralensis Houart, 1995 and L. minispinosus Houart, 1995 . All other species differ in many distinct ways.

Leptotrophon wareni n. sp. differs from L.segmentatus in having a narrower shell with a less acute spire,more widely spaced and lower spiral cords, more numerous and narrower spiral cords on the siphonal canal, and an aperture with adherent inner lip, contrasting with the widely flaring lip of L. segmentatus .

It differs from L. coralensis ( Fig. 3I, J) and L. minispinosus ( Fig. 3E, F), two species also with very high spires, in having a more nodose, less shouldered shell, broader axial varices, and in having more numerous visible spiral cords on early teleoconch whorls, L. coralensis and L. minispinosus having only one visible spiral cord (P1) from 1st to 4th teleoconch whorls in adult specimens, while the subsutural ramp in these species is also broader and more strongly sloping.

Leptotrophon coralensis Houart, 1995 ( Fig. 3 I-J)

Leptotrophon coralensis Houart, 1995: 483 , figs 70, 71, 120, 121.

TYPE MATERIAL. — Holotype (dd) MNHN 1022 .

NEW MATERIAL EXAMINED. — Coral Sea. EBISCO: stn CP2627, Chesterfield Reefs, S Lansdowne, 21°04’S, 160°49’E, 711-736 m, 1 dd ( MNHN).

TYPE LOCALITY. — Lansdowne-Fairway Ridge, 21°01’S, 160°57’E, 650-660 m [ CORAIL 2: stn DE14].

DISTRIBUTION. — Coral Sea, Chesterfields Reefs, bathymetric range for living specimens unknown, empty shells in 660- 711 m. REMARKS

This is the first record of Leptotrophon coralensis since its description and the second known specimen. It seems to be one of the rarest species of Leptotrophon from New Caledonia.The coordinates and depth are quite similar to those of the original material, which was also collected in the Coral Sea, Chesterfield Reefs at 21°01’S, 160°57’E, in 650- 660 m. The holotype and this additional specimen were both dead collected. The additional specimen closely matches the original description but due to its broken siphonal canal is not as high as the holotype, the height of which is 9.5 mm.