Typhinellus jacolombi, Houart, Roland, 2015

Houart, Roland, 2015, Description of a new species of Typhinellus (Gastropoda: Muricidae: Typhinae) from the Western Atlantic, Zootaxa 4007 (3), pp. 427-432 : 428-431

Typhinellus jacolombi n. sp.

( Figs 1 a–c; 2 a–k)

Type material. Holotype ( MNHN IM- 2000-30465: Figs 1 a; 2a–c), Caribbean Sea, Panama, Portobelo Bay, 37– 74 m. Paratypes: Caribbean Sea, Panama, Portobelo Bay, east of Canal Zone, 60 m, on muddy sand substrate, 1989, 2 RH; Caribbean Sea, Panama, Portobelo, 19–37 m, 1 JC; Caribbean Sea, Panama (no other data), 1 JC.

Other material examined. Caribbean Sea, Panama (no other data) 25 m, on coralline algae, 1 JC; Caribbean Sea, Panama, off San Blas Islands, dredged at 120 m, Nov. 2000, 1 JC.

Type locality. Portobelo Bay, Caribbean Sea, Panama, 37– 74 m.

Etymology. The species is named for Jacques Colomb (Marseille, France), who kindly donated the holotype and loaned material from his collection.

Description of the holotype. Shell large for the genus, 19.2 mm in length at maturity. Length/width ratio 1.75, broad, nearly smooth, lightly built. Subsutural ramp broad, gently sloping, weakly concave. Light tan with lighter colored siphonal canal, dark brown subsutural area and 3 or 4 light brown spots on abapical part of outer apertural lip. Aperture white within. Spire high with 5 broad, convex, angulate, strongly shouldered, weakly spinose teleoconch whorls. Suture of whorls impressed. Protoconch eroded in the holotype. Axial sculpture of teleoconch whorls consisting of 4 high, thin, sharp lamellate varices per whorl, each with a short, open, inwardly curved shoulder spine. Apertural varix very broad, flange-like, lightly reflected dorsally, with broadly open, short spinelets at outer edge. Variceal flange extended to nearly the tip of siphonal canal. Shoulder spine of apertural lamellae strongly dorsally curved dorsally, connected to last teleoconch whorl by a broad, high laminar buttress (partition). Spiral sculpture of low, rounded, broad, smooth primary and secondary cords, and narrow tertiary cords: P1 (anal tube), P2 (shoulder spine), t, s2, t, P3, s3, P4, s4, P5, P6, ADP, MP and ABP. P1 with long, tapering, broad, ventrally sealed anal tube, forming an angle of approximately 85° with axis of shell. Only last tube completely hollow and functional, older tubes broken off and closed. Other spiral cords, from P2 to P6 corresponding to short, broadly open, blunt spinelets at apertural varix.

Aperture moderately large, roundly ovate, forming a continuous peristome. Columellar lip narrow, smooth within. Siphonal canal short, broad, tip partly broken in holotype, ventrally sealed. Left side of canal weakly overlapping right side.

Operculum light brown, thin, ovate, with subapical nucleus.

Radula unknown.

Distribution. Caribbean Sea, off the coast of northern Panama, from the San Blas Islands to the Gulf of Portobelo, in 25– 120 m.

Gertman (1969: 156) also mentioned Portobelo for the species he identified as Typhis (Typhinellus) sowerbii but he also added Egmont Key, Florida, at 41 fms (75 m), the Texas coast at 28 fms (51 m) and the Leeward Islands (near Nevis) at 50–60 fms (91–110 m). The specimen illustrated by Gertman (1969: 157, pl. 1, figs 5a–5c) from the Leeward Islands is close to T. lamyi and is here considered conspecific with that species. Having not seen the other specimens, I will at this time not enlarge the geographical range to the other two localities.

Remarks. The presence of Indo-West Pacific species in the Caribbean is highly improbable and their shell morphology differs in many ways from Typhinellus jacolombi n. sp. Typhinellus occlusus ( Garrard, 1963) and T. insolitus ( Houart, 1991) have a narrower shell with fewer spiral cords and a more strongly constricted last teleoconch whorl. Typhinellus bicolor and T. androyensis also have less spiral cords and a comparatively smaller shell and T. amoenus differs in having a narrower shell with a more strongly constricted last teleoconch whorl and less expanded variceal wings.

Of the two species reported from the western Atlantic, one, Typhinellus chipolanus ( Gertman, 1969) is a fossil species from the late lower Miocene (Burdigalian) of the Chipola Formation in Florida. It is different from the Recent species in having a smaller and slenderer shell, reaching 12.5 mm in the holotype, and in having fewer and shallower spiral cords. The other species, T. lamyi ( Fig. 2 l–n) ( Merle & Garrigues, 2014: 844) from Guadeloupe differs in having a smaller shell relative to the number of teleoconch whorls, in having a less expanded variceal flange and in lacking any secondary spiral cords.

The Mediterranean T. labiatus ( Fig. 3 a–n) ( Cristofori & Jan 1832: 11) also occurs in a small area in the eastern Atlantic and has been confused with the new Panamanian species (see above) but it consistently differs in having a generally smaller shell, although one of the syntypes of Typhis sowerbyi , a synonym, in NHMUK measures 24.5 mm in length ( Houart, 2001: 122, fig. 129). However, that species also differs in having a narrower shell compared to its length, with a length/width ratio of 1.68–1.77 compared to 1.50–1.72 in T. jacolombi n. sp. and in having a different spiral sculpture morphology ( Fig. 1 d), T. labiatus has the primary cords IP to MP with s 2 in all the examined shells and an occasional s 4. I never observed any other secondary cords in T. labiatus contrary to T. jacolombi n. sp., which always has a s2 spiral cord, often s3, less often s4 and rarely s5 and abs ( Fig. 1 a–c). T. jacolombi occasionally has a smoother shell than observed in the holotype ( Fig. 2 g –j ) but T. labiatus has a less broad and less expanded apertural wing abapically and a more constricted last teleoconch whorl.

Typhinellus jacolombi varies in shell colour, ranging from completely white with darker brown subsutural area (paratype RH) to completely light brown (paratype RH) ( Fig. 2 d–f ). The protoconch (paratype JC) is small and rounded ( Fig. 2 k ) and the total shell length may attain 28.7 mm ( Fig. 2 d–f ).

Figures

FIGURE 1. Spiral cord morphology. a – c. Typhinellus jacolombi n. sp. a. Panama, Portobelo Bay, 37 – 74 m, holotype MNHN IM- 2000 - 30465, length: 19.2 mm; b. Panama, Portobelo Bay, 60 m, muddy substrate, coll. 1989, paratype RH, length: 28.7 mm; c. Panama, Portobelo, 19 – 37 m, paratype JC, length: 19.3 mm; d. Typhinellus labiatus (Cristofori & Jan, 1832), Kerkennah, Tunisia, 0.5 m, RH, length: 20.1 mm; e. Typhinellus lamyi Garrigues & Merle, 2014, Guadeloupe, Port Louis, 66 m, holotype MNHN-IM- 2013 - 7776, length: 13.1 mm.

FIGURE 3. Typhinellus labiatus (Cristofori & Jan, 1832). a – c. Kerkennah, Tunisia, 0.5 m, RH, length: 20.1 mm; d – f. Kerkennah, Tunisia, 0.5 m, RH, length: 19.7 mm; g – h. Kerkennah, Tunisia, 0.5 m, RH, length: 18.1 mm; i. Mallorca, Porto Colom, 1978, RH, length: 16.6 mm; j. Italy, Livorno, 26 m, 1978, RH, length: 13.6 mm; k – m. Sardinia, RH, 14.4 mm; n. Protoconch, Sicily, Brucoli, 1990, RH (scale bar 500 µm).

FIGURE 2. a – k. Typhinellus jacolombi n. sp. a – c. Panama, Portobelo Bay, 37 – 74 m, holotype MNHN IM- 2000 - 30465, length: 19.2 mm; d – f. Panama, Portobelo Bay, 60 m, muddy substrate, coll. 1989, paratype RH, length: 28.7 mm; g – h. Panama, Portobelo, 19 – 37 m, paratype JC, length: 19.3 mm; i – j. Panama, Caribbean (no other data), paratype JC, length: 21.7 mm; k. Protoconch of specimen figured in i – j (scale bar 500 µm). l – n. Typhinellus lamyi Garrigues & Merle, 2014, Guadeloupe, Port Louis, 66 m, holotype MNHN- IM- 2013 - 7776, length: 13.1 mm.