Acanthopleura echinata (Barnes 1824)

Animal of very large size, up to 158 mm in examined specimens. Tegmentum smooth to shiny (but often eroded), dark reddish-brown, with occasional small blue spots. Lateral areas hardly raised, smooth except for two radial rows, one of 5–9 round granules indenting sutural edge. Anterior valve with some 10 radial rows of round granules; space between rows smooth. Central areas with raised, well-defined, smooth jugal band bordered by shallow, longitudinal grooves with short, wavy, longitudinally oriented riblets on pleural areas. Girdle upper surface with erect, strong, spike-like spines, round in cross section, up to 8 mm long in large specimens (longer if not broken), often encrusted. Girdle bridges empty (After Ferreira 1986). According to Osorio (2002) this is a dioecious species, which can reach a maximum length of 200 mm.

According to Ferreira (1986) this species is found from Talara, Peru (04°34’S; 81°16’W) to Punta Tumbes, Bahía de Concepción, Chile (36°49’S; 73°03’W), and is limited to the intertidal zone and shallow subtidal, 0–4 m depth, on rocks often exposed to heavy surf.