Carenzia trispinosa ( Watson, 1879 )

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 : 539-541

Carenzia trispinosa ( Watson, 1879)

( Figs. 7–8 )

Synonymy see Quinn (1983a). Complement:

Seguenzia trispinosa: Rios, 1975: 32 (fig. 104); 1985: 33 (fig. 142); Carenzia trispinosa: Quinn, 1983a: 358 (figs. 8–12); Rios, 1994: 45 (pl. 14, fig. 154); Rios, 2009: 73 (textfig.); Rosenberg et al., 2009: 622.

Type locality: Challenger station 120; 8°37’S 34°28’W, 1115 m ( Quinn 1983a). Distribution: Western Atlantic Ocean, from North Carolina, USA, to Argentina, off Río de la Plata, 684–2360 m depth ( Quinn 1983a; Rios 2009).

New occurrence: Southeastern Brazil, from Espírito Santo to Rio de Janeiro, 1540–1872 m depth.

Description: Shell small, broadly conical (1.1 times as wide as tall), keeled, relatively delicate. Color nacreous white to creamy. Protoconch slightly less than one whorl, rounded, bulging, with smooth surface; transition indistinct, but probably congruent with beginning of medial spiral cord on first teleoconch whorls. First 2–3 teleoconch whorls sculptured by smooth medial spiral cord, becoming nodulose on later whorls; remaining whorls also sculptured by strong nodulose spiral cord at periphery, forming distinct keel; nodules expanding axially toward adjacent cords, forming faint axial ribs especially on three last whorls. Basal portion of body whorl usually smooth except for very delicate sinuous growth lines and strong spiral cord, forming subsutural carina and producing distinct concave zone adjacent to peripheral keel. Whorls convex. Suture shallow, but well-marked. Aperture quadrangular, with strong columellar tooth and two labral sinuses: a moderately deep subsutural and a shallower one adjacent to columellar region. Umbilicus moderately wide (1/5 of shell diameter), deep; umbilical periphery smooth, well-marked.

Measurements (in mm): 6–6¼ whorls, H = 3.3 ± 0.3, D = 3.8 ± 0.33, h = 1.3 ± 0.2, d = 1.5 ± 0.2.

Measurements (in mm): 6– 6¼ whorls, H = 3.3 ± 0.3, D = 3.8 ± 0.33, h = 1.3 ± 0.2, d = 1.5 ± 0.2.

Material examined: BRAZIL: Espírito Santo: off São Mateus, continental slope of Abrolhos, 18°59’S 37°47’W, 1540–1550 m, MNHN, 6 shells, MZSP 116290, 2 shells (MD55, sta. DC70, 26/v/1987); 19°01’S 37°47’W, 1500–1575 m, MNHN, 7 shells, MZSP 116291, 2 shells (MD55, sta. CB79, 28/v/1987); 19°40’S 37°48’W, 790–940 m, MNHN, 0 1 shell, (MD55, sta. CB77, 27/v/1987); Rio de Janeiro: 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, 1 shell, (MD55, sta. CB108, 02/vi/1987).

Remarks: Some specimens show several (7–8) thin axial threads on the basal portion of the last whorl. The strength and quantity of the nodules is also very variable among specimens. The new records are within the known distribution.

Figures

FIGURES 7 – 12. Carenzia and Hadroconus from the MD 55 expedition. 7 – 8. Carenzia trispinosa from Espírito Santo; 7. MNHN (MD 55 sta CB 77), apertural view (H = 3.6 mm); 8. MNHN (MD 55 sta DC 70), protoconch detail under SEM (scale bar = 0.1 mm); 9 – 12. Hadroconus altus from Rio de Janeiro; 9. MNHN (MD 55 sta CB 99), apetural view (H = 6.0 mm); 10. Same, umbilical view under SEM (D = 7.1 mm); 11. Same, protoconch detail under SEM (scale bar = 0.1 mm); 12. same, apical, slightly umbilical view under SEM.