Murexsul (Murexsul) jahami, Merle & Garrigues, 2011

Merle, Didier & Garrigues, Bernard, 2011, Description of four new species of Muricidae (Mollusca, Gastropoda) from the Philippines and the Caribbean area, Zoosystema 33 (4), pp. 557-575 : 568-570

Subgenus Murexsul Iredale, 1915

Murexsul (Murexsul) jahami n. sp. ( Fig. 7A, B )

Muricidae sp. – Pointier & Lamy 1998: 104.

TYPE MATERIAL. — Martinique. 250 m deep, holotype ( MNHN. IM.24630) (H: 26 mm) and 1 paratype (Coll. DL) (H: 25 mm).

TYPE LOCALITY. — Martinique. Eastern Martinique, Peninsula Caravelle.

ETYMOLOGY. — Named in honour of Patrice de Jaham.

DESCRIPTION OF HOLOTYPE

Protoconch unknown. Teleoconch biconic, of seven whorls, 26 mm high, 21.8 mm wide (including spines). Last (seventh) whorl 62% of total height. Spire tall, apical angle 54° (excluding spines), 118° (including spines). Spiral sculpture of marked primary cords. First whorl not seen. Second whorl: P1, P2 and P3 present. Third whorl: no change. Fourth whorl: appearance of primary cord IP (on sutural ramp), secondary cords adis and abis (on sutural ramp), s1 and s2. Fifth whorl: P2 atrophied. Sixth whorl: P2 atrophied further. Seventh whorl: adis, IP and abis (on infrasutural ramp), P1 to P5, s1 to s5 (on convex part of whorl), and P6 and ADP present (on siphonal canal). P1, P3 and P4 and ADP cord spines hypertrophied, P5 spine slightly atrophied, P2 and P6 spines more atrophied. Longest spines (P1) distally bifid. First and second whorls with seven varices each. Six varices present on each of third to penultimate whorls. Last whorl with five varices. Microsculpture finely scabrous due to slightly erected growing lamellae. Aperture oval, 27.5% of diameter (including spines), 59.6% of shell height. Columellar lip smooth, erect, adherent only adapically. No anal sulcus. Outer lip finely crenulate, denticles varying in prominence: ID and D1+D2 (fused denticles); D3 to D5 split. Siphonal canal 30.8% of shell height, narrowly open, weakly recurved dorsally. Pseudumbilicus narrow. Colour pale tan with a darker spiral band between P3 and P4.

INTERSPECIFIC COMPARISONS

Murexsul jahami n. sp. belongs to the American members of the group of Murexsul (M.) oxytatus (Smith, 1938) defined by Merle & Houart (2003) and discussed later by Houart (2006). Some of them have been placed previously in Muricopsis Bucquoy & Dautzenberg, 1882 by Vokes (1994). In this group, species with spiny patterns bear strongly developed P1, P3, P4 and ABP spines, poorly developed P5 spines, atrophied P2 spine, and the P6 spine generally missing. In this group, M. (M.) jahami n. sp. can be compared with M. (M.) oxytatus ( Fig. 7D ), M. (M.) zylmanae (Petuch, 1993) ( Fig. 7F ), M. (M.) chesleri Houart, 2006 ( Fig. 7E ) and M. (M.) sunderlandi (Petuch, 1987) ( Fig. 7C .). Murexsul (M.) oxytatus , M. (M.) zylmanae and M. (M.) chesleri are three very closely similar species. They are easily distinguishable from M. (M.) jahami n. sp. by their higher spire, their less inflated last whorl, and their narrower aperture. The inner lip can be ornamented by one or two columellar tubercles in some specimens of M. (M.) oxytatus and M. (M.) chesleri , whereas it is smooth in M. (M.) jahami n. sp. Murexsul (M.) sunderlandi from the Bahamas resembles M. (M.) jahami n. sp. more closely in sharing an inflated last whorl. Nevertheless, the surface of M. (M.) jahami n. sp. is very scabrous, whereas it is almost smooth in M. (M.) sunderlandi . Considering the primary cord spines, P1, P3, P4 and ADP are strongly hypertrophied and the distal part of these spines is weakly open in M. (M.) jahami n. sp., while they are not so well-developed in M. (M.) sunderlandi . Moreover, spine MP is present in M. (s.s.) sunderlandi , whereas it is missing in M. (M.) jahami n. sp. In the aperture, the columellar lip is adherent in M. (M.) sunderlandi , whereas it is erected in M. (M.) jahami n. sp.

Figures

FIG. 7. — Primary cords and internal denticles of the outer lip of Murexsul (s.s.) jahami n. sp., M. (s.s.) sunderlandi (Petuch, 1987), M. (s.s.) oxytatus (Smith, 1938), M. (s.s.) chesleri Houart, 2006 and M. (s.s.) zylmanae (Petuch, 1993): A, B, ventral and dorsal views, M. (s.s.) jahami n. sp., holotype MNHN.IM.24630 (H: 26 mm); C, M. (s.s.) sunderlandi, Coll. BG, Bahamas (H: 18.40 mm); D, M. (s.s.) oxytatus, Coll. BG, Rosalind Bank, Honduras (H: 21.6 mm); E, M. (s.s.) chesleri, Coll. BG, Roatan Island, at 5 m deep, Honduras (H: 21.4 mm); F, M. (s.s.) zylmanae, holotype, Great Isaacs Cay, Bahamas (H: 31 mm), photo courtesy of Megan Paustian (CMNH). Scale bar: 10 mm.