Barnacle (Balanus tintinnabulum) / Craca (Balanus tintinnabulum)

A cirripede crustacean of the Balanidae family, relatively common on the coastal rocks of the Madeira and Savage Islands. It is found in certain areas and lives at the water's edge, preferring sites exposed to the strong impact of the waves. Although it very rarely appears in the market, it is edible and is rightly appreciated as a tasty seafood. To collect it, a percussion instrument called a 'craqueira' is used, as the shell that covers it is intimately attached to the rock where it lives. It is one of the 13 cirripedes mentioned by C. Darwin as being from Madeira in his monograph on this order of crustaceans.