Turbonilla tupinamba, Pimenta, Alexandre D. & Absalão, Ricardo S., 2002

Pimenta, Alexandre D. & Absalão, Ricardo S., 2002, On the taxonomy of Turbonilla puncta (C. B. Adams, 1850) (Gastropoda, Pyramidellidae), with the description of a new species from Brazil and remarks on other western atlantic species, Zootaxa 78, pp. 1-16 : 11-13

Turbonilla tupinamba sp. n. ( Figs. 33­37 )

Type Locality: off Prainha (22 58'S, 0 42 00'W), Arraial do Cabo, Rio de Janeiro State, Southeast of Brazil.

Type material: Holotype: MNRJ 8944, off Prainha, Arraial do Cabo, Rio de Janeiro State, 1989, T.Almeida coll. Paratypes: MORG 41060 and ANSP 410354, Arquipélago de Santana, Macaé, Rio de Janeiro State, v/1993, AG coll.; MZSP 35855, off Cabiúnas, Rio de Janeiro State, 21/iv/1993, AG coll.; MNHN, off Espírito Santo State, 18/iii/ 1993, Eq. Zoo coll.; ZMA 4.02.0 27, off Piúma, Espírito Santo State, 1993, F.Pitombo coll.; IBUFRJ 8330, off Espírito Santo/Rio de Janeiro States, 26­27/viii/1979, NOAC coll.

Additional material examined: ­ Espírito Santo State: IBUFRJ 8561, off Piúma, 1993, F.Pitombo coll. [5]; ­ Rio de Janeiro State: IBUFRJ 8986, Arquipélago de Santana, Macaé, v/1993, AG coll. [1]; IBUFRJ 8987, Prainha, Arraial do Cabo, 1989, T.Almeida coll. [1]. Etymology: Tupinambá (“the main political leader”, in the Indian language Tupi) is a generic name of many Brazilian Indian tribes which used to live along the Brazilian coast.

Description: Shell white, elongate, with slight pupoid shape. Teleoconch with up to 10 whorls; first 3­4 teleoconch whorls convex in profile, while others whorls somewhat sinuous in profile slightly concave just below suture and slightly convex in anterior half. Protoconch of type A­I, with around 2.5 whorls, oriented 100o to shell axis. Axial ribs sinuous, slightly opisthocline, not continuing through the base; 7th whorl with 23 to 28 ribs on, while 8th whorl 27 to 30. Coastal interspaces about equal to the rib width. Spiral sculpture consists numerous very fine striae. A couple of wider and deeper spiral grooves are present, one just above suture and another, not always present, at middle whorl. Base rounded, with very fine and waved spiral striae; without umbilical fissure. Aperture oval, lightly constricted in the posterior region. Columellar fold absent. Holotype with 10 teleoconch whorls. Dimensions of the holotype: length: 4.9 mm; width: 0.9 mm; protoconch diameter approximately 260 m. in width.

Remarks: Turbonilla tupinamba (figs. 33­37) has spiral sculpture very similar to T. puncta and T. deboeri , with the conspicuous wider spiral striae at the middle whorl and above the sutures (fig. 34, 35). The main characteristic that distinguishes T. tupinamba from T. puncta is the outline of the whorls, which are convex in the first three to four whorls of teleoconch (fig. 33, 35) and sigmoid in the remainder (fig. 35), while T. puncta has more regularly rectilinear whorls. In addition, the width of the whorls of T. tupinamba becomes almost constant from the 5th or 6th whorl on, giving the shell a more or less cylindrical shape in the latter whorls; in T. puncta , the growth pattern is more regular and the shells are more regularly conical. Turbonilla tupinamba has markedly sigmoid axial ribs with their apical extremities projecting over the sutures (fig. 35). Turbonilla puncta and T. deboeri have more rectilinear ribs with extremities that do not project over the sutures ( T. deboeri ) or project slightly ( T. puncta ).

Geographic notes: This work presents the first report of T. puncta , T. deboeri , T. westermanni and T. obsoleta at latitudes lower than 12° N. In Brazil (fig. 38), all these species are principally represented in the north and northeast coast, but T. deboeri , T. westermanni

and T. obsoleta range south to the coast of Rio de Janeiro State (23° S). Turbonilla tupinamba , on the other hand, is restricted to the southern coast of Brazil. Rios (1994) reported T. haycocki from the north coast of Brazil, without illustrating a shell from that region, but providing a copy of the illustration in Warmke & Abbott (1962). The synonymy of T. haycocki , T. peilei and T. puncta suggested here gives the latter a large geographical distribution, from Bermuda to the Northeast coast of Brazil.

Although the pyramidellid fauna from western Atlantic and that from estern Africa ( Aartsen, 1981; Peñas & Rolán, 1997; Schander, 1994) show great similarity in the morphology of the shells of the species, it is not the scope of this work to present a comparison between the two faunas. Such study is a pointer for future researches.

Figures

FIGURES 33 ­ 37: Turbonilla tupinamba n. sp.: 33 ­ holotype (MNRJ 8944), length: 4.9 mm; 34 ­ base of holotype; 35 ­ three last whorls of holotype; 36 ­ protoconch of paratype (ANSP 410354); 37 ­ protoconch of paratype (MZSP 35855). Scale bars: 300 m.