Shell cyrtoconoid in sub-adult specimens; more slender, but inflated, when adult. Top whorl heterostrophic; last whorl 2/3 of the total length, inflated, with fragile outer lip. Sculpture present only as flattened spiral cords, with narrow interspaces, covering the surface of the whorls, down to the base.
common size :
The heterostrophic apex, diagnostic feature of Pyramidellids. A. amoenus, as its congeneric A. fulvus, has no closely related to any of the Mediterranean Pyramidellidae. See A. fulvus for other distinguishing characteristics.
BIOLOGY / ECOLOGY
This species has been found alive in Mediterranean Sea, as a parasite of the bivalve Acanthocardia tuberculata (Linnaeus, 1758) (Oliverio, 1994).
fine sand, colonised by the seagrass Cymodocea nodosa, at 5 m depth (Oliverio, 1994).