Shell elongated-ovate, steeply conical, with an apical hole at approximately 1/3 of the way from anterior end. Outer surface with 20-25 major radiating ribs and some smaller ribs interpersed; comarginal ridges less developed than the ribs and forming knobs at their intersection. Margin of the aperture with conspicuous crenulations where the ribs terminate, the notches between crenulations somewhat continued towards the inside of the shell.
shell whitish with radial sectors bearing dark blotches, inside white with external patterns showing through.
common size :
up to 20 mm long, 10 mm high in the Red Sea; more commonly 15 mm long.
This species resembles the native D. graeca (Linnaeus, 1758) but has a steeper profile, coarser sculpture, and different appearance of the edge of the aperture with notches distinctly continued towards inside. Some morphs of D. graeca found in deeper water of the Western Mediterranean may be misleading, but these are usually larger and have more continuous dark sectors on the shell (not blotches).
BIOLOGY / ECOLOGY
Species of Diodora feed on sponges lining the underpart of rocks.
on rocky intertidal zone; also on gravel bottoms dredged 20-70 m (Barash and Danin, 1992).