Barnacles are arthropods of the subclass Cirripedia in the subphylum Crustacea. They are related to crabs and lobsters, with similar nauplius larvae. Barnacles are exclusively marine invertebrates; many species live in shallow and tidal waters. Some 2,100 species have been described.
Balanus is a genus of barnacles in the family Balanidae of the subphylum Crustacea.
Thecostraca is a class of marine invertebrates containing over 2,200 described species. Many species have planktonic larvae which become sessile or parasitic as adults.
Balanus glandula is one of the most common barnacle species on the Pacific coast of North America, distributed from the U.S. state of Alaska to Bahía de San Quintín near San Quintín, Baja California. They are commonly found in the upper intertidal zone on mussels, rocks and pier pilings. They can obtain oxygen from both water and air.
The Balanidae comprise a family of barnacles of the order Balanomorpha. As a result of research published in 2021 by Chan et al., the members of the family Archaeobalanidae were merged with this family.
Semibalanus balanoides is a common and widespread boreo-arctic species of acorn barnacle. It is common on rocks and other substrates in the intertidal zone of north-western Europe and both coasts of North America.
Sessilia is an unranked clade of barnacles, comprising the barnacles without stalks, or acorn barnacles. They form a monophyletic group and are probably derived from stalked or goose barnacles. Sessilia is divided into two orders. The Verrucomorpha contain two families, Verrucidae and Neoverrucidae, and the remaining 14 families are in the order Balanomorpha.
The Balanomorpha are an order of barnacles, containing familiar acorn barnacles of the seashore. The order contains these families:
Balanus nubilus, commonly called the giant acorn barnacle, is the world's largest barnacle, reaching a diameter of 15 cm (6 in) and a height of up to 30 cm (12 in), and containing the largest known muscle fibres.
Amphibalanus improvisus, the bay barnacle, European acorn barnacle, is a species of acorn barnacle in the family Balanidae.
Hemioniscus balani, a species of isopod crustacean, is a widespread parasitic castrator of barnacles in the northern Atlantic Ocean. Its range extends from Norway to the Atlantic coast of France, and as far west as Massachusetts. It is also commonly found on the Pacific coast of North America; it is not known if the Pacific and Atlantic populations are the same species, or if the Pacific population exists following human-assisted introduction.
Balanus balanus is a species of acorn barnacle in the Balanidae family. It is native to the colder seas of the northern hemisphere.
Balanus crenatus is a species of acorn barnacle in the Balanidae family. It is found in the North Pacific and the North Atlantic Ocean.
Megabalanus stultus is a species of barnacle first described by Charles Darwin in 1854. It lives on fire corals of the genus Millepora in the Atlantic Ocean from Florida to southern Brazil.
Megabalanus tintinnabulum is a species of large barnacle in the family Balanidae. It is the type species of the genus. The specific name comes from the Latin tintinnabulum meaning a handbell and probably refers to the fact that small groups of barnacles resemble clusters of miniature bells.
Megabalanus coccopoma, the titan acorn barnacle, is a tropical species of barnacle first described by Charles Darwin in 1854. Its native range is the Pacific coasts of South and Central America but it is extending its range to other parts of the world.
Semibalanus cariosus, commonly known as the thatched barnacle, rock barnacle or horse barnacle, is a species of acorn barnacle occurring in the northern Pacific Ocean.
Megabalanus azoricus, the Azorean barnacle, is a species of large barnacle in the family Balanidae. It is endemic to Macaronesia: the Azores, Madeira, the Canary Islands, and Cape Verde. It is the largest and third most common shallow water barnacle of the Azores, where it is heavily exploited for food and has a high commercial value since the colonization of the islands. It was included in the 100 species for priority management within Macaronesia. It is a thoracopodal filter feeder and the majority are hermaphrodites. It is more abundant in the first 3 m (9.8 ft) on the low intertidal and infralittoral rocky shores. The empty shells of the barnacles are a vital habitat for the blennies Parablennius ruber, P. incognitus and Coryphoblennius galerita as they provide shelter and substrata for egg deposition during reproduction. A large number of invertebrate species also use the empty shells. Although present throughout the archipelago, it is more abundant in the eastern islands. It has a genetic similarity with Megabalanus tintinnabulum. Some crucial features of the M. azoricus species are digonic hermaphroditism in sessile adults, development of planktotrophic larvae, dependence on exposed rocky shores in the intertidal habitat, and insular distribution restricted to the northeastern Atlantic oceanic islands.
