Subcancilla joapyra, Simone & Cunha, 2012

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 : 766-768

Subcancilla joapyra n. sp.

( Fig. 8 A-D)

TYPE MATERIAL. — Holotype: Brazil, Espírito Santo, off Itaúnas, continental slope of Abrolhos, 18°59’S, 37°50’W, 295 m depth, MNHN 25241 ( Fig. 8A, B ) ( MD 55, stn DC 75, Bouchet, Leal & Métivier coll., 27. V.1987). Paratypes: same data as holotype, MNHN 25242, 1 shell ( Fig. 8C, D ), MZSP 102675, 1 shell.

TYPE LOCALITY. — Brazil, Espírito Santo, off Itaúnas, continental slope of Abrolhos, 18°59’S, 37°50’W, 295 m depth ( MD 55, stn DC 75).

DISTRIBUTION. — Only known from type locality.

ETYMOLOGY. — The specific epithet is derived from the native Parintintin language, from “joapyr”, meaning elongate ( Betts 1981).

DIAGNOSIS. — Shell elongated; whorls weakly rounded, aperture as long as spire. Sculpture uniform, strong and relatively tall spiral cords (four in penultimate whorl), with uniformly conspicuous striae in interspaces. Four columellar folds.

DESCRIPTION

Shell: size up to 25 mm, outline narrowly fusiform; width c. 31% of length.Colour white, with wide, pale brown to beige spiral band in middle and inferior levels of each whorl, with irregular and unclear borders ( Fig. 8 A-C). Protoconch eroded, apparently with three whorls, surface smooth ( Fig. 8A, B ); limit with teleoconch clear. Spire c. 50% of shell length; spire angle c. 30°.Teleoconch with about five whorls; each whorl rounded, weakly concave; suture clear, but shallow. Sculpture strong, with relatively tall spiral cords, four in penultimate whorl, and c. 15 in body whorl; interspaces c. 3 times wider than cords, fulfilled by uniform, cord-like, axial striae ( Fig. 8B, D ), c. 60 in penultimate whorl, interspace between striae equivalent to their width. Ventral region of penultimate whorl spiral cords becoming more oblique and closer to each other towards anterior, keeping narrow smooth triangular region close to siphon ( Fig. 8A, C ). Aperture elliptic, weakly oblique, comprising c. 48% of shell length and c. 30% of shell width; about 3 times longer than wide. Outer lip simple, lacking striae inside. Inner lip weakly concave, with weak callus and narrow anal canal ( Fig. 8A, C ); four columellar folds uniformly distributed in middle third of inner lip, two upper folds large and similar with each other, two anterior folds successively diminishing, anterior fold c. 3 times smaller than upper folds ( Fig. 8C ), almost invisible outside.Canal relatively wide, short; slightly narrower than aperture. No umbilicus.

MEASUREMENTS (in mm). — Holotype: 23.3 × 7.4; paratype MNHN 25242 : 24.2 × 8.0 (broken shell); paratype MZSP 102675 : 15.6 × 5.7 (spire and lip broken).

HABITAT. — Sandy-mud bottoms, 295 m depth.

REMARKS

In the Atlantic, Subcancilla joapyra n. sp. has only a feeble similarity with Subcancilla larranagai (Carcelles, 1947) , from south Brazil to north Argentina, and with S. straminea Adams, 1853 , from North Carolina to north Brazil. It differs by its sculpture, which is constituted by relatively tall spiral cords, with evident uniform axial striae; the sculpture of the other two species is constituted by wide spiral threads, with no uniform holes in the interspaces (compare Figure 8D and H ). Besides, S. joapyra n. sp. differs in having deeper suture, more convex whorls and more uniform sculpture patterns.

Subcancilla joapyra n. sp. is also similar to the fossil Miocene species Ziba venezuelana Hodson, 1931 , from Venezuela, and Z. senecta (White, 1887) , from Pará, Brazil; it differs in being more elongated, and in having more spiral cords per whorl. It differs from Z. candida (Reeve, 1845) , which occurs from the Caribbean Islands to northeast Brazil, 16-100 m depth, in being much more elongated, in having whorls less convex, more elongated aperture, and larger number of spiral cords. It differs from Subcancilla leonardhilli Petuch, 1987 and S. lindae Petuch, 1987 in having more developed sculpture between spiral cords, in being more elongated and whorls less concave.

Subcancilla joapyra n. sp. is somewhat similar to the Indo-Pacific species Ziba abyssicola (Schepman, 1911) (collected from 128-1340 m depth – Cernohorsky 1991), differing by the more elongated profile, by longer body-whorl, and the more acuminate profile of the spiral cords. It is also similar to Subcancilla rufogyratus Poppe, Tagaro & Salisbury, 2009 , from Philippines, differing in having fewer spiral cords, and in these not being coloured. Regarding to the delicate sculpture, S. joapyra n. sp. resembles Ziba intersculpta (Sowerby, 1870) , from which it differs by deeper suture and more elongated outline.

Subcancilla cf. straminea (Adams, 1853) ( Fig. 8 E-H)

MATERIAL EXAMINED. — Brazil, Espírito Santo, off Itaúnas, continental slope of Abrolhos, 18°59’S, 37°48’W, 607-620 m depth, MNHN ( MD 55, stn DC 73, Bouchet, Leal & Métivier coll., 27. V.1987).

MEASUREMENTS (in mm). — 14.7 × 5.3.

REMARKS

The single specimen collected is young, broken and relatively eroded, but some interesting information can be extracted from its analysis. Some similarity is found with two species, S. larranagai ( Cernohorsky 1991: 31, 33, pl. 24, figs 1-3) and S. straminea ( Cernohorsky 1976: 465, 466, pl. 416, figs 1-4), in both cases, the examined specimen is disjunct from their known distribution: S. larranagai is known from Santa Catarina, south Brazil, to Punta Médanos, north Argentina; while S. straminea occurs from North Carolina to Pará, north Brazil. Espírito Santo is approximately in the mid-way between both areas. The sculpture of the examined specimen ( Fig. 8F, H ) is somewhat similar to that of S. larranagai , consisting of wide spiral threads, with shallow pits, irregularly distributed in the interspaces; the sculpture of S. straminea is not so different, but the spiral threads usually are wider. Subcancilla larranagai is larger, with most specimens over 50 mm long, while S. straminea is not larger than 30 mm; the examined specimen is only 14.1 mm long, and the fashion of its whorls looks more similar to first teleoconch whorls of S. straminea than that of S. larranagai . The outline of S. larranagai is more elongated, with length c. 5 times longer than the width; in this aspect, the examined specimen is more similar to the S. straminea , which is c. 3 times longer than wide. However, the columellar folds of the examined specimen are unlike any of the both species, having only three folds ( Fig. 8E, G ). The descriptions of S. larranagai normally refer to four folds, while those of S. straminea usually refer to five. This difference in columellar folds is the main reason for the doubt in the specific identification. A conservative approach is given here considering the specimen as a dubious S. straminea , with a consequent southward extension of its geographic distribution.

Family VOLUTOMITRIDAE Gray, 1854

Figures

FIG. 8. — Mitrids: A, Subcancilla joapyra n. sp., holotype MNHN 25241, apertural view (L 23.3 mm); B, same, dorsal view; C, paratype MNHN 25242, apertural view (L 24.2 mm); D, same, detail of sculpture in penultimate whorl; E, Subcancilla cf. straminea (Adams, 1853), MNHN (stn DC73), apertural view (L 14.7 mm); F, same, dorsal view; G, same, detail of inner lip, apertural-slightly right view; H, same, detail of sculpture in penultimate whorl.