Carenzia carinata ( Jeffreys, 1877 )

Salvador, Rodrigo B., Cavallari, Daniel C. & Simone, Luiz R. L., 2014, Seguenziidae (Gastropoda: Vetigastropoda) from SE Brazil collected by the Marion Dufresne (MD 55) expedition, Zootaxa 3878 (6), pp. 536-550 : 539

Carenzia carinata ( Jeffreys, 1877)

( Figs. 4–6 )

Synonymy see Quinn (1983a). Complement:

Seguenzia carinata: Rios, 1975: 32 (fig. 102); Rios, 1985: 33 (fig. 139); Rolán, 2005: 49 (fig. 113). Carenzia carinata: Quinn, 1983a: 356 (figs. 1–7); Haszprunar, 1988: fig. 2Q [sensu Kano, 2007]; Rios, 1994: 45 (pl. 14, fig. 153); Gofas et al., 2001: 184; Rios, 2009: 73 (textfig.); Rosenberg et al., 2009: 622; Segers et al., 2009: 5.

Type locality: Valorous station 13, North Atlantic; 56°01’N 34°42’W, 1263 m ( Quinn 1983a).

Distribution: Amphi-Atlantic distribution, from the northern end of the Mid-Atlantic Ridge to the Canary Islands and from Florida, USA to the northeastern Brazilian coast; 732–2311 m depth ( Quinn 1983a; Rios 2009; Rosenberg et al. 2009).

New occurrence: Southeastern Brazil, from Espírito Santo to Rio de Janeiro, 790–3450 m depth.

Description: Shell small, broadly conical (nearly twice as wide as tall), strongly keeled, relatively thickwalled. Color homogeneous white to cream. Protoconch (~1 whorl) rounded, bulging, with pitted surface; transition visible as orthocline suture. Teleoconch smooth, except for strong spiral cord at periphery forming distinct keel and usually weaker median spiral cord on each whorl; both cords may bear rounded nodules, especially on last two whorls; nodules expanding axially toward adjacent cords, forming faint axial ribs, particularly on first two whorls. Basal portion of body whorl usually smooth, except for 1–2 very thin spiral threads near peripheral keel, and faint axial growth lines. Upper portion of whorls (above median cord) convex, and lower portion concave, resulting in a step-like profile. Suture shallow, but well-marked. Aperture quadrangular, acuminate toward peripheral keel, with strong columellar tooth. Umbilicus wide (1/4–1/5 of shell diameter), deep; umbilical periphery usually rounded and smooth, except for small nodules near the peristome.

Measurements (in mm): 4¾–6¼ whorls, H = 1.8 ± 0.1, D = 3.1 ± 0.9, h = 0.75 ± 0.1, d = 1.0 ± 0.1.

Material examined: Brazil: Espírito Santo: off São Mateus, continental slope of Abrolhos, 18°59’S 37°47’W, 1540–1550 m, MNHN, 34 shells, MZSP 116278, 15 shells (MD55, sta. DC70, 26/v/1987); 19°00’S 37°48’W, 950–1050 m, MNHN, 6 shells, (MD55, sta. DC72, 27/v/1987); 19°01’S 37°47’W, 1500–1575 m, MNHN, 1 shell, (MD55, sta. CB79, 28/v/1987); 19°08’S 37°34’W, 3450 m, MNHN, 2 shells, MZSP 116276, 1 shell (MD55, sta. DS66, 25/v/1987); 19°40’S 37°48’W, 790–940 m, MNHN, 17 shells, MZSP 116275, 9 shells (MD55, sta. CB77, 27/v/1987); Rio de Janeiro: E of Cabo de São Tomé, 21°25’S 39°56’W, 1400–1420 m, MNHN, 5 shells, MZSP 116277, 4 shells (MD55, sta. DS05, 09/v/1987); E of Cabo Frio, 22°50’S 40°15’W, 1835–1872 m, MNHN, 1 shell, (MD55, sta. SY03, 09/v/1987); S of Cabo Frio, 24°12’S 42°15’W, 1555 m, MNHN, 2 shells, (MD55, sta. CB108, 02/vi/1987).

Remarks: This species was reported by Clarke (1961) from the southeastern Atlantic, but this record was considered doubtful by subsequent authors ( Laubier & Bouchet 1976; Quinn 1983a). The new records expand the range of this species more than 1,000 km southward, from NE to SE Brazil.

Figures

FIGURES 1 – 6. Ancistrobasis and Carenzia from the MD 55 expedition. 1 – 3. Ancistrobasis costulata from Espírito Santo; 1. MNHN (MD 55 sta DC 75, H = 4.0 mm), apertural view; 2. MNHN (MD 55 sta DC 73), protoconch detail under SEM (scale bar = 0.1 mm); 3. Same, lateral view under SEM (H = 2.8 mm). 4 – 6. Carenzia carinata from Espírito Santo; 4. MNHN (MD 55 sta DC 70), apertural view (H = 2.0 mm); 5. Same, apical view under SEM (D = 3.5 mm); 6. Same, protoconch detail under SEM (scale bar = 0.1 mm).