Balanus Balanoides -

Adults generally reach up to 15 mm in diameter , though some records suggest they can range up to 7.5 cm in certain conditions.

It is famous in ecological studies for its competition with the barnacle Chthamalus stellatus . While Balanus can outgrow and smother Chthamalus in lower, wetter areas, it cannot survive as high up the shore as Chthamalus due to a lower tolerance for drying out. balanus balanoides

It uses long, feathery appendages called cirri to filter plankton from the water. Habitat and Ecology Adults generally reach up to 15 mm in