Gymnobela chyta Watson 1881

• Main Authors: Figueira, Raquel Medeiros Andrade, Absalão, Ricardo Silva
• Format: Other/Unknown Material
• Language: unknown
• Published: Zenodo 2012
• Subjects: Biodiversity; Taxonomy; Animalia; Mollusca; Gastropoda; Neogastropoda; Raphitomidae; Gymnobela; Gymnobela chyta; Northeast Atlantic; Northwest Atlantic
• Online Access: https://doi.org/10.5281/zenodo.5632977; http://treatment.plazi.org/id/8E7187D88E2E675447C0E329FBCA6F68

Gymnobela chyta (Watson, 1881) (Figs. 31–32) Pleurotoma ( Defrancia ) chyta Watson, 1881: 466. Clathurella chyta (Watson, 1881): Watson (1886: 358, pl. 18, fig. 4); Gymnobela chyta (Watson, 1881): Bouchet & Warén (1980: 58, fig. 110); Pleurotoma ( Defrancia ) peripla Dall, 1881: 68; Dall (1889: 115, pl. 11, fig. 17). Type material : Holotype BMNH 1887.2.9.1108 Type locality : West of Azores, sta. 73 (38º30’N, 31º14’W), 1829 m. Material examined : 16469 [1] OP I # 13; 16421 [4] OP I # 15; 16440 [3] OP I # 16; 16594 [2] OP II # 13-2; 16617 [3] OP II # 15; 16541 [16] OP II # 16-1; 17205 [1] OP I # 44; 14961 [1] OP I # 54; 19178 [2] OP I # 61. Description : Shell moderately plump, spire moderately high, yellowish, up to 44.48 mm long. Protoconch with about five whorls. Protoconch 1 with spiral rows of tiny crosses. Protoconch 2 with diagonal cancellation on the lower 2/3 of the whorls and arched axial riblets on the upper third. Clear-cut proto-teleoconch boundary. Teleoconch whorls with a strong shoulder at the upper part, forming a concave region between the suture and the whorl shoulder. Axial sculpture consists of many short prosocline axial riblets below the suture but not reaching the whorl shoulder, and 12–14 opisthocline axial folds (on the sixth whorl). Axial folds strongly angled on the whorl shoulder, extending to the base and becoming weaker toward the aperture. Numerous feeble spiral threads evenly sculpture the entire surface of the whorls below the shoulder, including the base. Concave region between the suture and the whorl shoulder crowded with minute granules. Suture moderately shallow. Base medium-sized. Anal sinus hardly discernible. Inner lip thin and reflected over parietal wall. Outer lip thin. Anterior siphonal canal short and wide. Aperture elliptical. Geographic distribution : Northeast Atlantic: Azores (Watson, 1886); Spain (Bouchet & Warén, 1980). Northwest Atlantic: Mexico (Dall, 1881; Dall, 1889). Southwest Atlantic: Campos Basin, Rio de Janeiro (this paper). Bathymetry : 750 m ...