Shell heavy solid, medium sized, strongly inequivalve. Lower valve (rv) deeply concave with large attachment area. Lv (upper) rather flat. Outline irregular, often subcircular. Sculpture of closely spaced lamellae which end as narrow spines but are usually worn out. Internal margin smooth but traces of crenulations may be present along the posterior margin. Big, rounded muscle scars.
externally no coloration except in very old specimens when purple tinges appear between lamellae. Internally a deep purple around the margins.
common size :
to 40 mm.
The solid shell and the deep purple internal coloration are diagnostic features of typical P. corbieri.
Details of dentition in the upper valve of a Red Sea specimen.
photo: S. Xentidis / Goulandris Museum
BIOLOGY / ECOLOGY
Epifaunal, immobile, cemented inhabitants of rocky shores and coral reefs. Chamids are stenohaline nearshore species.
areas with little sedimentation; often cemented to massive rocks in exposed areas, from the midlittoral zone to a few meters depth (Bernard, 1976). Specimens of Pseudochama attach themselves to substrate by the right valve.