Terebra leptapsis Simone, 1999

Simone, Luiz Ricardo L. & Cunha, Carlo M., 2012, Taxonomic study on the molluscs collected in Marion-Dufresne expedition (MD 55) to SE Brazil: Xenophoridae, Cypraeoidea, mitriforms and Terebridae (Caenogastropoda), Zoosystema 34 (4), pp. 745-781 : 776-778

Terebra leptapsis Simone, 1999

( Fig. 11 I-K)

Terebra leptapsis Simone, 1999: 229-233 , figs 7F, 12B, C, 13F, 14C, G, 21, 22; 2000: 138, 144-149. — Faber 2007: 50 (in synonymy), figs 10, 11. — Lima et al. 2007: 65. — Rosenberg 2009 (in synonymy). — Terryn 2011: 66.

Terebra leptaxis – Faber 2007: 50 (error).

TYPE MATERIAL ( EXAMINED). — Holotype: Brazil, Rio de Janeiro, Campos Bay , c. 21°7’S, 40°53’W, MZSP 28704 ( Fig. 11 I-K) ( R / V Austrogagoupa).

Paratypes: same data as holotype, MZSP 28705, 1 specimen, MZSP 28706, 13 shells.

MATERIAL EXAMINED. — The same as Simone (1999: 229).

TYPE LOCALITY. — Brazil, Rio de Janeiro, Campos Bay, c. 21°7’S, 40°53’W ( R / V Austrogagoupa).

DISTRIBUTION. — Rio de Janeiro to São Paulo.

DESCRIPTION

See Simone (1999: 229-233).

MEASUREMENTS (in mm). — Holotype: 16.0 × 4.5.

HABITAT. — Sandy bottoms, 32-64 m depth.

Terebra doellojuradoi Carcelles, 1953 ( Fig. 11 E-H)

Terebra doello-juradoi Carcelles, 1953: 14 , 15, pl. 3, fig. 21.

Terebra doellojuradoi – Scarabino 2004: 323, 234. — Faber 2007: 50 (in part). — Lima et al. 2007: 63. — Rosenberg 2009. — Terryn 2011: 66.

N.B.: all remaining citations for samples north from Uruguay almost certainly represent misidentifications and belong to other species of the complex, and, therefore, were excluded from this synonymic list.

TYPE MATERIAL ( EXAMINED). — Holotype: Uruguay, 35°53’S, 53°54’W, 61.88 m depth, MACN 23439 ( Fig. 11 E-G) . Paratypes: Uruguay, Mar del Plata , Banco de Mejillones, MACN 10319 , 1 shell ; 35°53’S, 53°54’W, 61 m, MACN 24278 , 1 shell ; 36°25’S, 54°38’W, 54 m, MACN 23439 , 1 shell ( Fig. 11H ) .

TYPE LOCALITY. — Uruguay, 35°53’S, 53°54’W, 61.88 m depth.

DISTRIBUTION. — Uruguay to north Argentina.

DESCRIPTION

See Carcelles (1953: 14). Complement:

Shell: up to 20 mm, width c. ¼ of length, spire angle c. 20°. Colour uniform beige to pale brown ( Fig. 11E, G ). Protoconch pointed, smooth, of three whorls ( Fig. 11F ); width c. 14% of maximum teleoconch width; length c. 5% of shell length. Limit between protoconch and teleoconch distinct, orthocline ( Fig. 11F ). Teleoconch up to 10 whorls; profile weakly convex, suture clear but shallow. Sculpture of all teleoconch whorls with about same arrangement of threads. Except for increment of axial and spiral threads; c. 24 axial threads and c. 10 threads in penultimate whorl, axial threads slightly broader and spiral threads; spiral threads not uniform in size and distance from each other, but lying in a somewhat equidistant arrangement from each other, space between neighbouring axial threads about twice each thread width; interval between axial threads equivalent to their width. Sculpture of peri-umbilical area composed of 8-9 spiral liration along entire surface ( Fig. 11E ). Aperture somewhat prosocline, elliptic, about 1.5 longer than wide. Outer lip thick, simple. Inner lip with weak callus; parietal region in upper third, marked by abrupt curve in c. 90°; siphonal region marked by bright curve to left ( Fig. 11E ). Canal short, narrow, slightly curved to left.

MEASUREMENTS (in mm). — Holotype: 10.2 × 2.4; paratype MACN 24278: 8.5 × 2.2.

HABITAT. — “Rocky bottoms” (sic Carcelles 1953:14), 54-100 m depth.

DISCUSSION ON TEREBRIDS

Several aspects of the characters of the species belonging to the Terebra doellojuradoi complex can be found elsewhere ( Simone 1999, 2000; Simone & Gracia 2006). The present paper was more focused on the four studied species, mainly concerning the MD55 collected specimens, and to the taxonomic problem related to T. leptapsis .

Terebra leptapsis has been considered a synonym of T. doellojuradoi , in such the differences pointed out in the original description of the former ( Simone 1999) have been overlooked ( Faber 2007: 50; Rosenberg 2009). However, a closer look of the type specimens of T. doellojuradoi deposited at MACN revealed additional characters which are incompatible with such interpretation.Two of T. doellojuradoi types are shown in Figure 11 E-H ( Fig. 11 E-G: holotype; Fig. 11H : paratype) for a comparison with the holotype of T. leptapsis ( Fig. 11 I-K). Terebra doellojuradoi is smaller, with length around 18 mm (the holotype is 20.5 mm long), while T. leptapsis specimens commonly are over 25 mm long. The sculpture of both species is quite variable, possessing some overlap of characters, but both holotypes are good specimens to show that T. doellojuradoi normally bears more spiral threads than T. leptapsis (compare penultimate whorl in Figure 11E and I ). The inverse happens with axial sculpture, in which T. leptapsis tends to possess more axial threads (c. 30 in penultimate whorls) than T. doellojuradoi (c. 20 in the same region). Regarding to the sculpture, both species are clearly closely related when compared to other species of the T. doellojuradoi complex, e.g., T. crassireticula ( Fig. 11L ) and others. The spire angle is also a quite different, T. doellojuradoi has about 20°, while T. leptapsis normally has 15-17°. The aperture is also informative, as T. doellojuradoi has a somewhat shorter and slightly broader one than T. leptapsis ( Fig. 11E, H, I ). However, the protoconch bears the solidest features for distinction of both species; that of T. doellojuradoi is multispiral (about three whorls) ( Fig. 11F ) and proportionally narrower and smaller than the protoconch of T. leptapsis , which is paucispiral (c. 1.5 whorl) ( Fig 11J ).

Based on these differences, it looks improbable that Terebra leptapsis is a synonym of T. doellojuradoi , and represents a distinct species. The former occurs from Uruguay to north Argentina, the latter occurs in southeastern Brazil. Besides, based on this study and on the endemicity of the species of the T. doellojuradoi complex, the occurrence of T. doellojuradoi in other regions is indeed questionable, such as Gulf of Mexico ( Bratcher & Cernohorsky 1987). Those reports have not been neither considered here.

The presence of a columellar callus or tooth in the inner lip has been regarded as appearing only in the maturity ( Faber 2007: 50). This is not accurate, as the columellar fold has been found running along columella in broken specimens (e.g., Terryn 2011: 65, fig. 5), which suggests its presence since immature phases. The columellar tooth is more common in northern species, and has been virtually absent in southern specimens, mainly those occurring in southeastern Brazil to north Argentina ( Figs 10C ; 11E, I ), including T. doellojuradoi . Conversely, T. alagoensis possesses a pair of teeth in the inner lip ( Fig. 11D ), which is a distinction of this species amongst the other species of the T. doellojuradoi complex.

Figures

FIG. 11. — Terebrids:A, Terebra alagoensis Lima,Tenório & Barros, 2007,holotype MZSP 84238 (L 10.5 mm), frontal view;B, C, details of apical region in two opposite views; D, detail of last whorl, frontal-slightly profile view; E, Terebra doellojuradoi, holotype MACN 23439, frontal view (L 10.2 mm); F, same, detail of protoconch and first whorls; G, same, profile view; H, paratype MACN 24278, frontal-slightly profile view (L 8.5 mm); I, T. leptapsis, holotype MZSP 28704, frontal view (L 16.0 mm); J, detail of protoconch in SEM; K, dorsal view; L, T. crassireticula, holotype MZSP 27930 (L 22.0 mm).

FIG. 10. — Terebrids: A, Terebra assu Simone n. sp, holotype MNHN 25244, frontal view (L 9.8 mm); B, paratype MZSP 102598, profile view (L 8.3 mm); C, holotype, detail of last whorl, frontal view; D, E, first whorls in two opposite views; F, T. alagoensis Lima, Tenório & Barros, 2007, MNHN (stn CB92), frontal view (L 4.9 mm); G, MZSP 102607 (1), frontal view (L 4.1 mm); H, I, protoconch of Figure F in two opposed views.