Eubela limacina ( Dall, 1881 )

Figueira, Raquel Medeiros Andrade & Absalão, Ricardo Silva, 2012, Deep-water Raphitomidae (Mollusca, Gastropoda, Conoidea) from the Campos Basin, southeast Brazil, Zootaxa 3527, pp. 1-27 : 9-10

Eubela limacina ( Dall, 1881)

( Figs. 9–11 )

Pleurotoma (Bela) limacina Dall, 1881: 55 ;

Daphnella limacina: Verrill (1882: 452) ; Dall (1889: 106, pl. IX, fig. 10);

Eubela limacina: Powell (1966: 129, fig. A3–60, pl. 20, fig. 24) ; Absalão et al. (2005: 33, fig. 89); Rios (2009: 347, species 900);

Pleurotoma (Defrancia) hormophora Watson, 1881: 457 .

Clathurella hormophora ( Watson, 1881) : Watson (1886: 351, pl. XXI, figs. 9a–c).

Type material: Syntypes MCZ 7108, MCZ 7109, MCZ 7110, MCZ 7111

Type locality: Gulf of Mexico, Blake sta. 2, 1472 m; Yucatan Strait, 1170 m; Gulf Stream, 817 m.

Material examined: Type material and 18402 [6] OP II # 44; 18403 [44] OP II # 49; 15919 [2] OP II # 67; 15540 [3] OP II # 69; 17307 [3] OP II # 74; 18404 [1] OP II # 75; 17170 [14] OP I # 44; 15051 [22] OP I # 49; 17055 [2] OP I # 59; 15348 [7] OP I # 74; 18405 [1] OP I # 75; 18406 [2] B # 32; 13847 [2] 13° 22’S 38°36’W, 750 m, 02–03/VIII/2001.

Description: Shell high, turreted, white, up to 7.32 mm long. Protoconch with 4.5 whorls, yellow. Protoconch 1 with rows of tiny crosses. Protoconch 2 with somewhat curved axial riblets crossed by fine spiral threads on the posterior portion of the whorls and with diagonal reticulation on the anterior portion. Clear-cut proto-teleoconch boundary. Teleoconch with up to five whorls, slightly convex, with a subsutural row of beads, which is covered by numerous very fine spiral threads. Suture very shallow. Base smooth, short and convex, with inflexion to form a short anterior siphonal canal. Aperture elliptical (broken in the specimens studied here).

Geographic distribution: Northwest Atlantic: Massachusetts ( Verrill, 1882); Gulf of Mexico, Yucatan Strait, Gulf Stream ( Dall, 1881, Dall, 1889); Santa Cruz, Florida ( Dall, 1889). West Indies ( Watson, 1886); Amapá, Brazil ( Rios, 2009). Southwest Atlantic: Pernambuco ( Watson, 1886); Bahia ( Absalão et al., 2005), Campos Basin, Rio de Janeiro (this paper). Bathymetry: 20 m ( Absalão et al., 2005)– 1596 m (this paper).

Discussion: The material studied here is composed almost entirely of young specimens, which match well with the original description of E. limacina ( Dall, 1881: 55) and are very similar to the syntype (fig. 9). The only difference that we found was the presence of numerous fine spiral threads covering the subsutural row of beads. These threads were only observed in the SEM photomicrographs, and it is understandable that they were not reported by Dall.

Three species of the genus Eubela are reported for the western Atlantic ( Rosenberg, 2009): Eubela limacina ( Dall, 1881) , E. calyx ( Dall, 1889) and E. mcgintyi Schwengel, 1943 . E. mcgintyi ( Schwengel, 1943, pl. 7, figs. 4–5) does not have the subsutural row of beads observed in E. limacina . Both E. mcgintyi and E. calyx have spiral ornamentation on the fasciolar region, whereas E. limacina is completely smooth aside from the subsutural sculpture.

Eubela limacina was reported from Massachusetts, USA to Bahia, Brazil (41°N–13°S). Its distribution is here expanded further South to include Rio de Janeiro (21°–22°S). Its bathymetric range is also increased. The deepest depth previously reported was 1472 m ( Dall, 1881) and it has now been found at 1596 m.

Figures

FIGURES 1 – 11. 1, 2 — Aliceia aenigmatica Dautzenberg & Fischer, 1897, IBUFRJ 18442; 1 — 4.02 mm, whole shell; 2 — protoconch; 3, 4 — Famelica mirmidina Dautzenberg & Fischer, 1896; 1 — IBUFRJ 18465, 4.94 mm, whole shell; 2 — IBUFRJ 18452, protoconch; 5, 6, 7 — Neopleurotomoides aembe n. sp.; 5, 8 — Holotype MNRJ 30285; 5 — 3.18 mm, whole shell; 8 — detail of shell surface; 6 — Paratype MZSP 108228, 3.64 mm, whole shell; 7 — Paratype MNRJ 30286, protoconch; 9, 10, 11 — Eubela limacina (Dall, 1881); 9 — Syntype MCZ 7111; 10 — IBUFRJ 13847, 7.32 mm, whole shell; 11 — IBUFRJ 15348, protoconch. Scale bars: 1, 3, 5 and 6 = 500 μm; 2, 4, 7 and 11 = 300 μm; 8 = 50 μm; 9 and 10 = 1 mm.