Despite their appearance, goose barnacles are actually not mussels but a distant relative of crabs and shrimps. Like other barnacles, they belong to a group of crustaceans called Cirripedia.
Their body is enclosed in several plates that are attached to substrates, with only one body opening. The animal can close its body opening with the plates and can thus stay alive out of the water for days.
The body of goose barnacles is attached to substrates via a stalk. Two species of goose barnacles are distinguished; those that occur in the tidal zones on coastline (Pollicepes sp.) and those occurring on marine debris floating in the open ocean (Lepas anatifera).
Further names: Portuguese: Pedunculata; English: Leaf barnacle, Gooseneck barnacle
Prey: Plankton. The barnacles use their fan-like limbs to filter out food from the water.
Habitat and range: Colonise hard surfaces of any kind, at least partially immersed in seawater (rocks, driftwood, ship hulls, etc.)
Life cycle: These animals are hermaphroditic, i.e. they have both male and female reproductive organs. They copulate with their neighbours using their extraordinarily long penis. They carry their eggs in egg pouches under their shell. The larvae leave the mother’s shell and at first drift freely with the currents, forming part of the zooplankton community at this specific life stage. The larvae then attach themselves to a suitable substrate and develop into sessile (non-moving) adult goose barnacles.
Distinctive features: Adult animals have a long and muscular stalk (originally the front part of the head). The remaining body (corresponding to the back part of the head) contains the limbs, the digestive tract and the sexual organs. The upper part of the body is enclosed in a shell consisting of several plates.
Taxonomy: Subphylum: Crustacea (Crustaceans); Infraclass: Cirripedia (Barnacles)
Delicacy: The stalk of goose barnacles is edible. It counts as a delicacy in some Mediterranean countries. On the Iberian Peninsula, it is known as percebes.
Discover the curious mythological connection between goose barnacles and barnacle geese: