Shell solid, inequivalve, subequilateral; ovate. Cemented to substrate by the right (lower) valve. Attachment area usually small. Right valve more convex than the left one. Sculpture of numerous radial ribs with upstanding spines. Ribs dense with spins that are regularly spatulate, hollow underneath; interstices arrayed with smaller sharp spins. Umbones on top of a triangular cardinal area which is higher in the right valve. Ligament internal on the hinge plate. Inner margin crenulate.
shell mauve or brown, ivory-yellow and yellow on ribs and spines. Umbonal area yellow-white. Internal blue-white. Crenulated margin with tones of dark brown and yellow.
common size :
up to 140 mm in length and 80 mm in height.
It is difficult to identify the Spondylus species, they are similar in shape and color. Distinguishing characteristics are in ribs number and spines' appearance and color. Mauve or brown base color and yellow spins that are larger make S. multisetosus different from other Spondylus species.
BIOLOGY / ECOLOGY
attached to rocks, corals and other debris.