''Austromegabalanus psittacus'', the giant barnacle or ' as it is known in

Spanish Spanish might refer to: * Items from or related to Spain: **Spaniards are a nation and ethnic group indigenous to Spain **Spanish language, spoken in Spain and many Latin American countries **Spanish cuisine Other places * Spanish, Ontario, Can ...

, is a species of large barnacle native to the coasts of southern

Peru , image_flag = Flag of Peru.svg , image_coat = Escudo nacional del Perú.svg , other_symbol = Great Seal of the State , other_symbol_type = National seal , national_motto = "Firm and Happy f ...

, all of

Chile Chile, officially the Republic of Chile, is a country in the western part of South America. It is the southernmost country in the world, and the closest to Antarctica, occupying a long and narrow strip of land between the Andes to the east a ...

and southern

Argentina Argentina (), officially the Argentine Republic ( es, link=no, República Argentina), is a country in the southern half of South America. Argentina covers an area of , making it the second-largest country in South America after Brazil, th ...

. It inhabits the

littoral The littoral zone or nearshore is the part of a sea, lake, or river that is close to the shore. In coastal ecology, the littoral zone includes the intertidal zone extending from the high water mark (which is rarely inundated), to coastal a ...

and

intertidal The intertidal zone, also known as the foreshore, is the area above water level at low tide and underwater at high tide (in other words, the area within the tidal range). This area can include several types of habitats with various species ...

zones of rocky shores and normally grows up to tall with a mineralized shell composed of calcite. The ''picoroco barnacle'' is used in

Chilean cuisine Chilean cuisine stems mainly from the combination of traditional Spanish cuisine, Chilean Mapuche culture and local ingredients, with later important influences from other European cuisines, particularly from Germany, the United Kingdom and ...

and is one of the ingredients in

curanto Curanto (from arn, kurantu 'stony') is a traditional Chilote method of cooking food using heated rocks buried in a earth oven that is covered with pangue leaves and turf. The fundamental components are seafood, potatoes, along with other traditi ...

Description

''Austromegabalanus psittacus'' is a large

sessile Sessility, or sessile, may refer to: * Sessility (motility), organisms which are not able to move about * Sessility (botany), flowers or leaves that grow directly from the stem or peduncle of a plant * Sessility (medicine), tumors and polyps that ...

barnacle that lives in groups on hard substrates. It has a tall cone-shaped carapace composed of twelve large plates made of calcite microcrystals which are cemented together. The basal disc is firmly cemented to a hard surface. It grows to a height of . There is an opening at the top with a hinged operculum through which the thoracic limbs known as "cirri" protrude. The general colour is dull white with purple and brown markings.

Biology

''Austromegabalanus psittacus'' is a simultaneous hermaphrodite. Individual barnacles are fertilised by sperm passed through a slender tube extended by a neighbouring barnacle. The

eggs Humans and human ancestors have scavenged and eaten animal eggs for millions of years. Humans in Southeast Asia had domesticated chickens and harvested their eggs for food by 1,500 BCE. The most widely consumed eggs are those of fowl, especial ...

are retained inside the carapace where they are incubated for about three or four weeks. They then hatch into free swimming nauplius larvae which form part of the

plankton Plankton are the diverse collection of organisms found in water (or air) that are unable to propel themselves against a current (or wind). The individual organisms constituting plankton are called plankters. In the ocean, they provide a crucia ...

. These pass through six stages over the course of about 45 days, the last being a cyprid stage. These larvae are about long and settle on the seabed, usually in the proximity of other barnacles. Often the larvae settle so close together that hummocks are formed as the juvenile barnacles grow. Under these circumstances the calcareous base becomes modified into a more porous, cylindrical form above which the carapaces tower, the central individuals being about twice as tall as the outside ones. The density of the barnacles in the hummocks can be more than 1000 individuals per square metre (11 sq ft). This ability to form hummocks give this species an advantage when they are competing for space with other species of barnacle. It is an

omnivorous An omnivore () is an animal that has the ability to eat and survive on both plant and animal matter. Obtaining energy and nutrients from plant and animal matter, omnivores digest carbohydrates, protein, fat, and fiber, and metabolize the nut ...

filter feeder.

Distribution

''Austromegabalanus psittacus'' is a coastal species found in southern Peru, along the entire length of Chile (including offshore

Juan Fernández Islands The Juan Fernández Islands ( es, Archipiélago Juan Fernández) are a sparsely inhabited series of islands in the South Pacific Ocean reliant on tourism and fishing. Situated off the coast of Chile, they are composed of three main volcanic i ...

) and southern Argentina in the

and

zone. It is recorded at depths of , but is mostly found at . It is most common in the Los Lagos area in Chile and is harvested for human consumption, mainly in the towns of

Calbuco Calbuco is a city and commune in southern Chile administered by the Municipality of Calbuco. Administratively Calbuco belongs to the Llanquihue Province of Los Lagos Region. The origin of the city was the Spanish Fort Calbuco founded in 1603, an ...

, Carelmapu and Puerto Montt.

Use by humans and oceanic organisms

Austromegabalanus psittacus 20180130 -Mercado Central fRF

This barnacle forms part of Chilean cuisine. Its meat is highly prized and is one of the ingredients of the Chilean dish

. This is traditionally made from various seafood ingredients cooked in a large pit preheated with red-hot stones. Modern cooking methods use a large pot, conventionally heated. Overfishing has reduced the quantities of ''Austromegabalanus psittacus'' available for commercial harvesting. There are plans to cultivate it along the coast of Chile and there are possibilities of exporting it to Japan. In addition to humans, it is sometimes eaten by the sea star '' Heliaster helianthus'' and the clingfish '' Sicyases sanguineus'', although the latter only can prey on small animals (large ''Austromegabalanus psittacus'' are apparently safe).

References

{{Taxonbar, from=Q2706391 Barnacles Crustaceans of the eastern Pacific Ocean Edible crustaceans Invertebrates of Chile Crustaceans described in 1782