Shell depressed, ovate, rather thin, with distinctly curled apex at posterior margin, then slighly curled dextrally. Outer surface with irregular spiral threads and a scaly periostracum. Inside with a thin septum which covers roughly the posterior half of the shell.
greyish to buff with three blurred, dark brown spiral bands, not very distinct on the outer surface, vivid inside; septum white.
common size :
This species is distinguished from C. fornicata by being more depressed, having a more distinctly curled apex, having an external sculpture and having a color pattern of bands rather than blotches. Some native forms known as C. gibbosa Defrance, 1818, which may be forms of the common Mediterranean C. unguiformis Lamarck, 1822 living on a convex substrate, may resemble this species but are smaller and lack the brown bands and spiral sculpture on the outside. This species has been first recorded in the Mediterranean as Crepidula calyptraeiformis, but we follow the advice of Dr. G. Pastorino (of Museo Argentino de Ciencias Naturales, Buenos Aires) in considering this as a synonym of C. aculeata.
BIOLOGY / ECOLOGY
Specimens from the Pacific Ocean have been reported with large eggs and no pelagic larval stage (Ishiki, 1936). This species does not form stacks as does C. fornicata.
on rock substrates in shallow water.