Cranopsis apostrema Simone & Cunha, 2014, new species
Creators: name: Simone, Luiz Ricardo L.
name: Cunha, Carlo M.
Publisher: name: Zenodo
Year: 2014
Subjects: Biodiversity
Taxonomy
Animalia
Mollusca
Gastropoda
Lepetellida
Fissurellidae
Cranopsis
Cranopsis apostrema

description: Cranopsis apostrema new species
Figures 56–65
Types. Holotype MNHN 25300. Paratypes: MNHN 25301, 25 shells, MZSP 105509, 10 shells, MNRJ 25961, 4 shells; all from type locality. Brazil. Espírito Santo; continental slope of Abrolhos (MD55; Bouchet, Leal & Métivier col.; 27/v/1987); off Itaúnas, 18°59’S 37°48’W, 607–620 m, MNHN 25302, 3 shells (sta. DC73), 18°58’S 37°48’W, 682 m, MNHN 25303, 1 shell (sta. SY74); off Regência, 19°40’S 37°48’W, 790–940 m, MNHN 25304, 1 shell (sta. CB77). Rio de Janeiro; Campos Basin, 22°42’33.8”S 40°40’84.2”W, 110–120 m, MNRJ 17234, 1 shell (19/ix/2009).
Type locality. Brazil. Espírito Santo; off Itaúnas, continental slope of Abrolhos, 18°59’S 37°50’W, 295 m (MD55 sta. DC75; Bouchet, Leal & Métivier col., 27/v/1987).
Diagnosis. Apex curved posteriorly, located in middle level in profile. Height ca. 45% of length; width 66% of length. Sculptured by 53 radial cords, with pustules. Foramen flanked by low edges; located high on shell.
Description. Shell size ca. 5 mm; bluntly conical; height ca. 45% of length. Pure white. Protoconch of 1.5 rounded whorls (Fig. 60, 65); situated on right (Figs 57, 59); smooth, glossy; size 240 µm. Foramen cuneiform (pointed anteriorly), width 13% of length; located dorsally, preceding anterior slope; ca. 6% of shell width, ca. 25% of shell length; edges irregular (Figs 56, 61, 63). Groove anterior to fissure very narrow; flanked by cords of similar strength as neighbor cords. Beak curved dorso-posteriorly, located anterior to posterior 1/3 of shell length (in dorsal view), in middle of shell height in profile; teleoconch of one whorl, overall angle in lateral view ca. 110° (Figs 57, 59, 62, 64). Sculpture of ca. 53 (range 50–55) narrow primary radial cords (Figs 56–57, 59–64), with small pustules; gradually increasing in strength towards aperture; in ventral half secondary cords gradually appearing; each pustule separated from neighboring pustules in line by space ca.1/2 of its width; interspaces ca. twice as wide as cord; ca. 60 pustules along threads close to median line. Selenizone short, narrower than foramen; edges simple, low; smooth internally (Figs 56, 61, 63). Aperture planar (Figs 57, 59, 64) to slightly concave (Fig. 62); outline elliptical, width approximately 66% of length; edges smooth. Inner surface smooth, glossy (Fig. 58). Septum ca. 40% of shell height; twice as high as wide, ventral edge slightly concave, ca. 25% of aperture width; gradually narrowing up to posterior edge of fissure.
Measurements (in mm). Holotype: 4.8 by 2.5; Paratype MZSP 105509#1: 4.8 by 2.5 (Figs 61–62).
Distribution. Continental slope off Espírito Santo to Rio de Janeiro, Brazil.
Habitat. Sandy mud bottoms, 110–940 m (dead specimens).
Material examined. Types.
Etymology. The specific epithet is derived from the Greek, apo, meaning separate, and extrem, related to strike; an allusion to delicate radial sculpture of the shell.
description: Published as part of Simone, Luiz Ricardo L. & Cunha, Carlo M., 2014, Taxonomical study on the mollusks collected in Marion-Dufresne (MD 55) and other expeditions to SE Brazil: the Fissurellidae (Mollusca, Vetigastropoda), pp. 437-468 in Zootaxa 3835 (4) on page 448, DOI: 10.11646/zootaxa.3835.4.2, http://zenodo.org/record/249622