Shell equivalve, almost equilateral, inflated with a slight gape posteriorly. Outline oval; anterior margin roundish, posterior dorsal slope convex. Sculpture of irregularly spaced dense concentric ridges and lines, more pronounced at the anterior part of the shell, less prominent towards the posterior half. Pallial sinus small, oval. Margin smooth.
variable; externally from white to purple-buff either uniform or with radial rays. Umbones always purple. Internally white to deep purple.
common size :
30-40 mm width, 23-29 height; to 65 mm in the Eastern Arabia Sea (Bosch et al., 1995).
Very similar to Mactra olorina another Erythraean invader from which it differs by the color (see remarks under Mactra olorina) and in the concentric ridges: irregularly spaced in M. lilacea, evenly spaced ridges in M. olorina.
BIOLOGY / ECOLOGY
See notes on the biology of family under Mactra olorina.
littoral to sublittoral sands; the Mediterranean record on the beach of Bardawil lagoon and also from depths 6-9 m along the Israel coast.