Pleurotomella cala Watson 1886

• Main Authors: Figueira, Raquel Medeiros Andrade, Absalão, Ricardo Silva
• Format: Text
• Language: unknown
• Published: Zenodo 2012
• Subjects: Biodiversity; Taxonomy; Animalia; Mollusca; Gastropoda; Neogastropoda; Raphitomidae; Pleurotomella; Pleurotomella cala; Ricardo; Northeast Atlantic
• Online Access: https://dx.doi.org/10.5281/zenodo.5632985; https://zenodo.org/record/5632985

Pleurotomella cala (Watson, 1886) (Figs. 38–40) Clathurella cala Watson, 1886: 361, pl. XXVI, fig. 11; Pleurotomella cala (Watson, 1886): Rios (2009: 349, species 904). Type material : Syntypes BMNH 1887.2.9.113– 114 Type locality : South-east Atlantic, Sta. 335, 32° 24 ’S 15 °05’W, 2606 m. Material examined : Type material and 18980 [1] OP I # 48; 17596 [1] OP I # 68; 18981 [1] OP II # 58; 18982 [1] OP II # 63; 18983 [1] OP II # 77; 16484 [1] OP I # 9; 16710 [1] OP II # 6. Description : Shell wide, white, up to 8.28 mm long. Protoconch with about 2.5 whorls. Protoconch subcylindrical. Protoconch 1 flattened, with spiral rows of tiny crosses. Protoconch 2 with dominant curved axial ribs crossed by spiral threads on the upper half of the whorls, and diagonal cancellation on the lower half. Clear-cut proto-teleoconch boundary. Teleoconch whorls with a slightly concave area below the suture ornamented with slightly curved axial riblets and a fine spiral cord. Below this area the whorl is strongly convex and sculptured by about 14 prominent axial ribs (on the third whorl) that continue over the upper part of the base. Sharp equidistant spiral cords present over the convex part of the whorl, intercalating one stronger, one weaker, producing acute projections where they cross the axial ribs. About 33 spiral cords from the body whorl to the base. On the base, spiral cords are equal in strength and closer to each other than at the body whorl. Shell surface covered by weakly spirally organized granules. Suture shallow. Base medium-sized and concave. Anal sinus deep. Outer lip thin. Anterior siphonal canal relatively long and wide. Aperture ovate. Geographic distribution : Southeast Atlantic: (Watson, 1886); Southwest Atlantic: Rio Grande do Sul, Brazil (Rios, 2009); Campos Basin, Rio de Janeiro (this paper). Bathymetry : 176 m (Rios, 2009)– 2606 m (Watson, 1886). Discussion : This species can be distinguished from most of the others in the genus by the flattened subcylindrical protoconch. The only other species with this kind of protoconch is P. packardii (Fig. 41). Bouchet & Warén (1980) distinguished these species by the protoconch, which they stated is blunter in P. packardii . We were unable to recognize this difference. We noticed however that P . packardii has much smoother whorls, its axial ribs do not form the acute nodules observed in P . cala (Fig. 40). Our material is identical to the type of P . cala . Pleurotomella cala was reported in Brazil for Rio Grande do Sul State (30 ºS). Its distribution is here expanded further to include Rio de Janeiro (21–22 ºS). : Published as part of Figueira, Raquel Medeiros Andrade & Absalão, Ricardo Silva, 2012, Deep-water Raphitomidae (Mollusca, Gastropoda, Conoidea) from the Campos Basin, southeast Brazil, pp. 1-27 in Zootaxa 3527 on pages 20-22, DOI: 10.5281/zenodo.210977 : {"references": ["Watson, R. B. (1886) Report on the Scaphopoda and Gasteropoda collected by H. M. S. Challenger during the years 1873 - 1876. Report on the scientific results of the voyage of H. M. S. Challenger during the years of 1873 - 1876, 15 (42), 1 - 680, 53 pls.", "Rios, E. C. (2009) Compendium of Brazilian sea shells. pp. 668. Fundacao Universidade do Rio Grande, Rio Grande.", "Bouchet, P. & Waren, A. (1980) Revision of the Northeast Atlantic Bathyal and abyssal Turridae (Mollusca, Gastropoda). Journal of Molluscan Studies, Supplement 8, 1 - 119."]}