Barnacle
Guides
Amphibalanus
acorn barnacle
Amphibalanus is a genus of acorn barnacles in the family Balanidae, established by Pitombo in 2004 to accommodate species formerly assigned to Balanus. The genus contains multiple species including the widespread and economically significant Amphibalanus amphitrite and A. improvisus. These barnacles are characterized by their conical calcareous shells, cemented base, and planktonic larval stages culminating in a settlement-competent cyprid stage. Several species have become established outside their native ranges as invasive biofouling organisms in ports and harbors worldwide.
Chthamalidae
Chthamalid Barnacles
Chthamalidae is a family of small, intertidal barnacles in the superfamily Chthamaloidea. The family includes at least 56 recognized species across 14 genera. Members are distinguished by a primary shell wall of eight, six, or four plates without imbricating whorls, and a membranous or rarely calcareous basis. They occupy the highest intertidal zones, often in wave-washed habitats where other barnacle families cannot survive. Molecular studies have revealed extensive cryptic diversity, with many species separable only by DNA analysis.
Chthamalus
Chthamalus is a genus of small intertidal barnacles distributed across non-boreal coasts of the Northern Hemisphere and many regions of the Southern Hemisphere. The genus has been subject to extensive taxonomic revision due to morphological similarity among species, with molecular techniques revealing numerous cryptic species. Recent phylogenetic work has shown the genus to be paraphyletic, with Microeuraphia nested within it. Species in this genus are important ecological components of rocky shore communities, where they compete for space with other barnacle taxa.
Conchoderma auritum
rabbit-ear barnacle
Conchoderma auritum, commonly known as the rabbit-ear barnacle, is a pedunculate barnacle in the family Lepadidae. It is primarily known as a whale-associated barnacle, attaching to the shells of other barnacle species such as Coronula diadema on cetaceans. The species has also been documented on large pelagic fish including black marlin, representing a non-mammalian host association. It possesses distinctive tubular ear-shaped structures on the capitulum and feeds using short, thick-segmented cirri adapted for strong currents.
Coronula
whale barnacles
Coronula is a genus of whale barnacles in the family Coronulidae, comprising eight described species including both extant and fossil taxa. Extant species are obligate ectoparasites of cetaceans, attaching directly to whale skin using specialized morphological adaptations. The genus is notable for its deep host integration, with shell bases forming hollow coring tubes that penetrate whale tissue to achieve secure attachment. Coronula diadema is the best-studied extant species and serves as a model for understanding barnacle-cetacean symbiosis.
Coronula diadema
whale barnacle, humpback whale barnacle
Coronula diadema is a species of whale barnacle that lives exclusively on cetacean hosts, primarily humpback whales (Megaptera novaeangliae). First described by Carl Linnaeus in 1767, this barnacle attaches to whale skin using specialized coring structures and filter-feeds on plankton. The species exhibits simultaneous hermaphroditism and forms mating groups of up to nine individuals. Its crown-like appearance gives rise to both its scientific and common names.
Lepas
Goose Barnacles
Lepas is a genus of goose barnacles in the family Lepadidae, comprising pelagic crustaceans that attach to floating substrates using a flexible stalk. The genus includes at least eight described species, with Lepas anatifera being among the most widely distributed and studied. Members of this genus are characterized by their stalked morphology and calcareous shell plates, representing a distinctive lineage within the barnacle group.
Lepas anserifera
Goose Barnacle
Lepas anserifera is a pedunculate barnacle that attaches to floating substrates including driftwood, ships' hulls, and marine debris. It possesses a capitulum of six white calcareous plates supported by an orange, flexible stalk. The species exhibits rapid growth and early maturation, with individuals reaching reproductive size within approximately two weeks under favorable conditions. As a hermaphroditic filter feeder, it plays a role in marine neustonic communities and has a cosmopolitan distribution in temperate and tropical seas.