Mangelia costulata: Habitat: it lives in the infra-circalittoral zones. It prefers muddy-detrital bottoms. It was found into gastral cavities of Astropecten aurantiacus too. Distribution: it can be found all over the Mediterranean but never common.
Notes: very beautiful shell, unmistakable for its peculiar spiral sculpture. Outline rather slim in form, whorls almost flat and suture broad and undulating. Sculpture made by about 12 axial ribs, a little bit narrower than interspaces, sinuous and shouldered in the upper part so to give the shell a scalariform aspect. Spiral sculpture made by numerous thin and close little cords passing over the ribs too. Protoconch polygyral with three vitreous whorls. In the upper part the aperture presents one sinus not much clear and the external lip is thickened. Ground colour pattern changeable: from dirty white to dark brown, it is often present one dark streak below-suture. Even juvenile specimens are easily recognizable due to their typical spiral sculpture. The adult specimens average measures are around 10-12 mm in height. CLEMAM assign this species to the genus Beta and they consider Mangelia smithii (Forbes, 1840) as its synonym. For a long time this last species was considered as a distinct species on the basis of different number and different form of axial ribs and for the missing of the streak below-suture, brown in colour. Even Mangelia wareni Piani, 1980 is considered as a synonym of this species.