Cerithiella cepene, De, Silvio Felipe B. & De, José Carlos N., 2007

De, Silvio Felipe B. & De, José Carlos N., 2007, Two new species of Cerithiella (Apogastropoda: Cerithiopsidae) for the continental slope of Pernambuco (northeast Brazil), Zootaxa 1441, pp. 63-68 : 66-68

Cerithiella cepene n. sp.

( Figures 10–14 )

Type material: Holotype, MNRJ 10837 [length: 4.5 mm; width: 1.9 mm]; 2 paratypes, MORG 50.719; 1 paratype, ANSP 413608; 2 paratypes, MZSP 80483; 2 paratypes, MORG 50.720. All from type locality.

Type locality: Continental slope of Pernambuco ( Brazil), 08°46.5’00’’S, 34°44.5’00’’W, 690 m.

Description: Shell small, turriform, white ( Fig. 10 ). Protoconch paucispiral 1½ whorls, smooth, mamillated, inflate, bulbous ( Fig. 12 ), faint, sparse riblets mark transition to teleoconch ( Fig. 11 ). Teleoconch of approximately seven convex whorls, two spiral cords, sharp axial ribs. Adapical cord weaker, only subsutural; sub-peripheral abaxial cord developing pronounced keel in intersection with axial ornamentation ( Fig. 14 ). First post-nuclear whorl with 23–24 axial ribs. Penultimate whorl with 15 to 16 axial ribs. Body whorl with 17 axial ribs. Intersection of axial and spiral ornamentation forming sharp well-pronounced nodules on subperipheral cord ( Fig. 14 ). Suture weakly marked. Base flat, smooth, with longitudinal grooves, minute carinal thread at margin ( Fig. 13 ). Aperture sub-circular. Outer and inner lip concave. Parietal region smooth, faintly concave, with one weak spiral cord ( Fig. 13 ). Siphonal canal oblique, very short.

Etymology: Named in homage to the “Research and Management Center of Fishery Resources of the Northeastern Coast ( CEPENE /IBAMA)” for the performance of its team, especially Mr. Enílson Cabral, Mr. Antônio Clerton de Paula Pontes and Dr. Maria do Carmo Ferrão Santos for knowledge on deep-water benthic fauna resulting in a greater understanding of the malacofauna of northeast Brazil.

Distribution: Known only from the type locality.

Remarks: Cerithiella martensii ( Dall, 1889) resembles C. cepene in the sharp sculpture, strength of the suture, aperture shape with a short siphonal canal and flattened base, which is also marked by growth striae. Cerithiella martensii ( Dall, 1889) differs from C. cepene in that it is more elongated, with weakly defined riblets and three spiral threads, the anterior of which is stronger in both species, but more pronounced in the latter.

In C. metula and C. cepene , there are sharp axial ribs and nodules at the intersection with the spiral cords. In both, the adapical cord is commonly the weakest, but is nearly obsolete in C. cepene . In the northwestern Atlantic, specimens of C. metula described as C. whiteavesii [= Lovenella whiteavesii Verrill, 1880: 391 , 396; Verrill (1882: 522, pl. 42, fig. 7); Bouchet and Warén (1993: 594, fig. 1307)] are very similar to C. cepene in the shape of the whorls and number of spiral cords, which are also similarly positioned. In shallow waters down to 500–1000 m, C. metula ( whiteavesii ) also develops a strong sub-peripheral spiral keel, but is distinguished from C. cepene by the numerous axial ribs, as observed in Bouchet and Warén (1993: 595). A typical C. metula normally has four to five cords on the body whorl and three to four on the other whorls ( Fretter & Graham, 1982: 376, fig. 267).

Cerithiella cepene and C. enodis have a thin shell, smooth mamillated apex, oval aperture with an oblique siphonal canal and a base margin defined by a minute carinal thread. Cerithiella enodis can be easily separated by the presence of nine faintly concave whorls, with around 26 fine ribs on each whorl and spiral cords projecting a small carina only in the subsutural zone.

Figures

FIGURES 10 – 14. Cerithiella cepene n. sp. (SEM) [holotype – MNRJ, Figs. 10, 13 – 14)]: 10. Ventral view (length: 4.5 mm); 11. Apical view of the protoconch (paratype, MZSP); 12. Apical view of the protoconch (paratype, MZSP); 13. Shell base; 14. Detail of teleoconch ornament. Scale bars: Figs. 11 – 12 = 100 µm; 13 – 14 = 500 µm.