Mean live weight: 2500-7000 g. Body-wall thickness: 0.15 cm. Body firm, rigid, flattened ventrally (trivium). Bivium entirely covered with characteristic, large, leaf-shaped, lobate papillae. Trivium with brown to pink podia, more numerous on the radii, their disc about 0.04 cm in diameter, Mouth ventral, surrounded by a circle of conical papillae which are larger on dorsal side, and 20 large, brown tentacles. Anus terminal. Calcareous ring with large radial pieces and narrow interradials. Cuvierian tubules absent. Color variable on bivium, reddish orange to brown; trivium generally red; mature gonads deep purple. Spicules on tegument with cross-shaped spicules, spiny branched spicules (sometimes with median pillar), perforated plates, pseudo-tables, and grains; branched spicules larger in dorsal tegument and papillae; ventral podia with branched spicules, long rods, and large, multiperforated plates; tentacles with characteristic branched spicules, in form of a "rose-window".
Populations not reaching very high densities, with a mean of around 0.003 per square meter. Harvested by hand. Collected by skin diving or using diving gear (if not banned), making the populations very vulnerable, due to overexploitation. The processed product is of major quality and the demand is still high (Ref. 122).
