Barnacle Barnacle A barnacle is a type of arthropod constituting the infraclass Cirripedia in the subphylum Crustacea, and is hence related to crabs and lobsters. Barnacles are exclusively marine, and tend to live in shallow and tidal waters, typically in erosive settings. They are sessile (nonmotile) suspension feeders, and have two nektonic (active swimming) larval stages. Around 1,220 barnacle species are currently known. The name "Cirripedia" is Latin, meaning "curl-footed". The study of barnacles is called cirripedology. Barnacles are encrusters, attaching themselves permanently to a hard substrate. The most common, "acorn barnacles" (Sessilia), are sessile, growing their shells directly onto the
Barnacle goose Barnacle geese breed mainly on the Arctic islands of the North Atlantic. The three main populations, with separate breeding and wintering ranges, from west to east, are: Small numbers of feral birds, derived from escapes from zoo collections, also breed in other Northern European countries. Occasionally, a wild bird will appear in the Northeastern United States or Canada, but care must be taken to separate out wild birds from escaped individuals, as barnacle geese are popular waterfowl with collectors. Barnacle geese frequently build their nests high on mountain cliffs, away from predators (primarily Arctic foxes and polar bears), but also