Timbellus pannuceus, Roland & Virginie, 2015

Roland, Houart & Virginie, Héros, 2015, New species of Muricidae Rafinesque, 1815 (Mollusca: Gastropoda) from the Western Indian Ocean, Zoosystema 37 (3), pp. 481-503 : 486-488

Timbellus pannuceus n. sp.

( Figs 4 J-O; 7A)

TYPE MATERIAL. — Holotype (lv) MNHN-IM-2007-36940 BOLD ID BOMGA026-15, GenBank accession number KP697989 for COI gene KC860506 and 5 paratypes MNHN, 1 paratype coll. RH (as listed below).

TYPE LOCALITY. — Madagascar, between Nosy Be and Banc du Leven, 12°40’S, 48°12’E, 492-524 m [MIRIKY: stn CP3184].

MATERIAL EXAMINED. — Northwest Madagascar. MIRIKY: stn CP3184, between Nosy Be and Banc du Leven, 12°40’S, 48°12’E, 492- 524 m, 2 lv, 1 dd (holotype MNHN-IM-2007-36940 and 1 paratype (lv) MNHN-IM-2007-38031 BO LD ID BOMGA025-15, GenBank accession number KP697990 for COI gene KC86050, 1 paratype (dd) MNHN-IM 2000-30003. — Stn CP 3188, between Nosy Be and Banc du Leven, 12°31’S, 48°22’E, 298-301 m, 2 lv (1 paratype MNHN-IM-2000-30004; 1 paratype Coll. RH). — Stn DW 3197, West of Cap d’Ambre, 12°07’S, 48°58’E, 362-431 m, 3 dd. — Stn CP 3209, between Nosy Be and Banc du Leven, 12°43’S, 48°14’E, 291-353 m, (2 lv paratypes MNHN-IM-2000-30005). — Stn CP 3223, between Nosy Be and Banc du Leven, 12°46’S, 48°11’E, 430-488 m, 1 dd .

DISTRIBUTION. — North-western Madagascar, taken alive at 301- 492 m, shells at 431- 492 m.

ETYMOLOGY. — Latin, pannuceus , wrinkled. This species is named for the wrinkled surface of the shell.

DESCRIPTION

Shell medium sized for the genus, up to 22.6 mm in height at maturity (paratype MNHN). Height/width ratio 1.4 (holotype). Slender, narrowly-ovate, lightly built. Shoulder ramp strongly sloping, weakly concave.

Ivory-white, occasionally with a light tan spiral band between P4 and P5 and occasionally on shoulder ramp. Aperture white.

Spire high with 1.5 protoconch whorls and teleoconch with up to five narrow, very weakly shouldered whorls. Suture weakly adpressed.Protoconch small, whorls rounded, smooth, glossy, maximum width 900 µm. Terminal lip narrow, low, weakly curved.

Axial sculpture of teleoconch whorls consisting of very narrow, webbed varices starting from the first whorl. First to last teleoconch whorls with three varices. No intervariceal sculpture except narrow, low, growth striae. Spiral sculpture of moderately high, narrow, smooth primary and secondary cords. First whorl with very low P1, second and third with P1 and P2, s1 occasionally starting, fourth with P1, (s1), P2, s2, P3, last whorl with P1, (s1), P2, s2, P3, s3, P4, (s4), P5, P6, ADP, MP, ABP, (ads).

Aperture moderately large, roundly-ovate. Columellar lip narrow, more broadly expanded adapically, weakly flaring, rim partially weakly erect, adherent at adapical extremity. Anal notch shallow, broad. Outer lip smooth, occasionally with weak or strong denticles within: ID broad, low, D1- D6 narrower; aperture occasionally smooth or with only a few denticles visible, others obsolete. Siphonal canal moderately long, broad, weakly bent dorsally and abaxially, narrowly open, with variceal webbing extending to 50-60% of its length.

Operculum and radula not examined.

REMARKS

Eight Indo-West Pacific species are included in Timbellus , all with a similar shell morphology consisting of a protoconch of 1.5 to 1.75 smooth whorls, smooth or almost smooth teleoconch whorls and thin, webbed variceal wings. These are T. vespertilio (Kuroda, 1959) , T. flemingi (Beu, 1967) , T. fulgens (Houart, 1988) , T. levii (Houart, 1988) , T. marshalli (Houart, 1989) , T. stenostoma ( Houart, 1991) , T. crauropterus ( Houart, 1991) and T. rubidus (Houart, 2001) .

Four of these species ( T. flemingi , T. marshalli , T. crauropterus and T. rubidus ) do not need to be compared with T. pannuceus n. sp. due to important differences in shell characters. The remaining four differ from T. pannuceus n. sp. as follows.

Timbellus vespertilio ( Fig. 6A, B ) differs in having more strongly shouldered teleoconch whorls with a relatively broader shoulder ramp and a more obvious and broader shoulder cord (P1). It also has fewer obvious spiral cords on the teleoconch whorls and on the abapertural face of the variceal wings. Timbellus vespertilio is known only from southern Japan, the East China Sea and Taiwan.

Timbellus fulgens ( Fig. 4P, Q ) was described from New Caledonia and was identified from South Africa by Houart (1991). Similar specimens are now also recorded from Madagascar. However it differs from T. pannuceus n. sp. in having a much smoother shell and smoother variceal wings with much lesser obvious primary cords and obsolete secondary cords.

Timbellus levii , a species currently only known from New Caledonia and Tonga ( Houart & Héros 2008) has a larger shell, reaching 36 mm in height, with smooth teleoconch whorls, almost smooth, broader variceal wings and with a much narrower and higher aperture.

Timbellus stenostoma from New Caledonia has a much smaller and smoother shell, reaching 15 mm in height, with a much smaller aperture and a longer siphonal canal.

Figures

FIG. 4. — A-E, Vokesimurex aliquantulus n. sp., MIRIKY, stn CP3206, 70-74 m; A, B, paratype MNHN IM-2000-30002, 33.1 mm; C, D, paratype MNHN IM-2000- 30002, 22.6 mm;E, protoconch;F, G, Vokesimurex rectirostris (Sowerby,1881), Taiwan Strait,Coll.RH,68 mm;H, I, Vokesimurex sobrinus (A.Adams,1863);Tosa, Japan, Coll. RH, 51.3 mm; J-O, Timbellus pannuceus n. sp.; J, K, MIRIKY, stn CP3184, 492-524 m, holotype MNHN IM-2007-36940, 18.9 mm; L, M, paratype MNHN IM-2007-38031, 20.6 mm; N, detail of the aperture; O, protoconch; P, Q, Timbellus fulgens (Houart, 1988); MIRIKY, stn DW3215, 316-433 m, 22.5 mm. Abbreviations: See Material and methods. Scale bars: E, O, 500 µm.

FIG. 6. — A, B, Timbellus vespertilio (Kuroda, 1959), East China Sea, Coll. RH, 28 mm; C-G, Timbellus goniodes n. sp., C, D, ATIMO VATAE, stn CP3615, 284- 286 m, holotype MNHN IM-2000-30006, 23.7 mm; E, F, ATIMO VATAE, stn DW3552, 264-280 m, paratype MNHN IM-2000-30007, 14.8 mm; G, protoconch; H, Timbellus crauroptera (Houart, 1991); New Caledonia, BIOCAL, stn DW64, 250 m, holotype MNHN IM-2000-0132, 11.4 mm; I-M, Bouchetia wareni n. sp., Madagascar,MIRIKY,stn CP3189,346-376 m; I, J, holotype MNHN-2007-36941, 18.1 mm;K, L, MIRIKY,stn CP3183,paratype MNHN IM-2007-36941, 12.8 mm; M, protoconch; N, O, Bouchetia vaubanensis Houart,1986;South of New Caledonia,VAUBAN 1976-1978, stn DR01,480-500 m, holotype MNHN IM-2000-0885, 10.5 mm; P, Q, Flexopteron akainakares n. sp., ATIMO VATAE, stn DW3524, 307-319 m, holotype MNHN IM-2000-30012, 12.2 mm. Scale bars: G, M, 500 µm.