Goose Barnacle

Information about the lifespan of Lepas anatifera is not available, but some barnacle species live around six years or longer.

Lepas is the only genus of barnacles eaten by humans, and is considered a delicacy in some parts of the world.

Positive Impacts: food

Lepas anatifera often attach to the hulls of ships, increasing the drag and reducing speed and efficiency. Thus, barnacles are often removed from ships' hulls.

The eggs of Lepas anatifera are about 140-260 X 100-120 microns and hatch into free swimming larvae that undergo six specialized naupliar stages. Development to the 10 mm long, plankton-eating stage VI can take up to two months. The larvae then transforms into a cyprid, which is a non-feeding search and settlement stage. The cyprid larvae drift along the ocean currents until it identifies and attaches to a substratum. Once they are attached, cirri develop. Lepas anatifera reaches sexual maturity when the capitulum reaches 2.5 cm across. Sexual maturity occurs more slowly in cold waters than in warmer waters. Approximately 120 days after settlement these barnacles develop reproductive organs at temperatures between 10.2 to 18.4 ºC, but the reproductive development takes 30 days if the surface temperature of the water is around 25 ºC.

Development - Life Cycle: metamorphosis

Lepas anatifera is common and there are no current conservation programs for this species.

US Federal List: no special status

CITES: no special status

State of Michigan List: no special status

Little is noted about the communication in Lepas anatifera.

Perception Channels: tactile ; chemical

The barnacle goose (Branta leucopsis) was once thought to start life as a goose barnacle (Lepas anatifera) because no one had ever seen its nest.

Adult Lepas anatifera are filter feeders in the water and are food for various other species.

Lepas anatifera is predatory, capturing prey (shrimp, polyps, young flying fish) with the cirri. Goose barnacles also filter currents, using a feathery filter feeding apparatus. Populations of L. anatifera can also be divided into two groups-monophagous and polyphagous consumers. These two groups differ in their prey size, location, diet composition and diversity, and feeding apparatus morphology.

Animal Foods: fish; terrestrial non-insect arthropods; aquatic or marine worms; aquatic crustaceans; cnidarians; other marine invertebrates; zooplankton

Foraging Behavior: filter-feeding

Primary Diet: carnivore (Piscivore , Eats non-insect arthropods, Eats other marine invertebrates)

Lepas anatifera is a cosmopolitan barnacle, inhabiting most tropical and temperate seas throughout the world.

Biogeographic Regions: nearctic (Native ); palearctic (Native ); neotropical (Native ); australian (Native ); oceanic islands (Native ); atlantic ocean (Native ); pacific ocean (Native )

Other Geographic Terms: cosmopolitan

The main characteristic of Lepas anatifera is its heart-shaped bivalve shell, called a capitulum, that can grow up to 5 cm in length and surrounds the body and limbs. The capitulum is composed of five striated, glossy white, calcareous plates. The first pair of calcareous plates are located at the aperture and the end of the peduncle. The second pair is more distal, located near the aperture. The fifth plate, the carina, creates a spine that connects all the valves to one another. The capitular valve allows extrusion and extraction of six food-catching tentacular structures called cirri. The barnacle attaches to objects using its stalk or peduncle, which ranges in length from 4-90 cm. The peduncle is a part of the head and is attached by a basal disc and covered by a tough cuticle that is unarmored and flexible. Beneath the cuticle lie longitudinal muscles. Attachment is maintained with cement produced from the glands of the peduncle.

Range length: 50 (high) mm.

Other Physical Features: ectothermic ; heterothermic ; bilateral symmetry

Adult Lepas anatifera are protected by an outer shell, but still may be preyed on by gastropods, starfish, crabs, and others. As larvae, the barnacles lack a shell, making them vulnerable to planktivores.

Fiona pinnata, a pelagic sea slug, is a known predator of Lepas anatifera. The sea slug uses its jaws to grasp the barnacle near the junction of the stalk and shell, and then uses its radula to rasp. The barnacle soon gapes open, allowing the sea slug to consume the prey.

Known Predators:

• Fiona, Fiona pinnata

Lepas anatifera is a pelagic barnacle that can be found attached to a variety of floating objects, including driftwood, bottles, boats, buoys, macroalgal rafts, and turtles. It can also be found on fixed objects such as rocks and off-shore structures. This species is most abundant in tropical and subtropical waters where sea temperatures exceed 18-20 ºC.

Range depth: 0 to 2909 m.

Habitat Regions: temperate ; saltwater or marine

Aquatic Biomes: pelagic ; coastal

Other Habitat Features: intertidal or littoral

Unlike most barnacles, Lepas anatifera is hermaphroditic and individuals cross fertilize via a copulatory organ. The large protrusible penis is located on the ventral surface of the abdomen and its top is the opening of the male gonopore. The female gonopores are associated with the base of the first cirri.

Fertilization is internal and the young are brooded in the mantle cavity before they are released.

Average gestation period: 1 weeks.

Range age at sexual or reproductive maturity (female): 30 (low) days.

Range age at sexual or reproductive maturity (male): 30 (low) days.

Key Reproductive Features: simultaneous hermaphrodite; sexual ; fertilization (Internal ); ovoviviparous

In Lepas anatifera, cross fertilization is followed by oviposition of the eggs in the mantle cavity. After oviposition they develop past their first embryonic stages. The newly fertilized eggs develop for about a week before being released as free swimming nauplii.

Parental Investment: pre-fertilization (Provisioning); pre-hatching/birth (Protecting: Female)

Goose barnacles are marine crustaceans but, unlike many other members of their class, they are hermaphrodites, meaning that the animal has both male and female sexual organs. Their eggs hatch into free-swimming larvae, which drift with the ocean currents as one of the immense number of animals that comprise zooplankton. As they develop, the larvae attach themselves to an object by way of a strong stalk or 'peduncle'. Once they have attached themselves to an object, they do not move again unless torn off by accident. As they grow they develop a feathery feeding apparatus, which filters particles of food from the water as the current passes over it. This filter can be speedily withdrawn inside the hard capitulum when the barnacle feels threatened. If barnacles grow in sufficient numbers on the hull of a ship, they increase the vessel's drag though the water and have to be removed when the ship is dry-docked. However, they were considered a great delicacy in some parts of the world. Even in Cornwall, if a boat arrived with clusters of barnacles attached to the hull, they were scrapped off and sold for food.

As this species is not listed as threatened, there are currently no conservation programmes for goose barnacles.

Goose barnacles gave rise to one of the strangest of animal beliefs. The heart-shaped shell, or 'capitulum', is a chalky-white in colour and has black lines, which were thought to resemble the head of the barnacle goose Branta leucopsis. Because barnacle geese rarely nest in Britain no-one had ever seen their eggs or nests. It was supposed, therefore, that the geese 'grew up on the planks of ships' and the birds finally emerged clothed in feathers and flew away. This curious theory also provided a convenient way round the church's ban on eating meat or flesh on Fridays. As the barnacle goose was obviously “not born of the flesh” but from a barnacle, they could be eaten not just on Fridays but throughout Lent!

This species is found attached to rocks, the planking of wooden ships, on driftwood, discarded rope; in fact, anything floating or fixed. A related species has also been found attached to the bodies of whales.

Goose barnacles occur throughout most of the temperate seas of the world.

Common

Goose barnacles are common around the British coast and, apart from the ever-present threat of marine pollution, are not presently endangered.

Goose barnacles have a misleading name. They have nothing to do with geese. Just like acorn barnacles, goose barnacles are crustaceans. However, unlike acorn barnacles, goose barnacles stand on a stalk. They regularly stick out a 'dip-net' to fish food from the water. The dip-net is made up of transformed legs, similar to that of the acorn barnacle. Up till the 17th century, one thought that goose barnacles grew on trees and that they were larvae from barnacle geese. In fact, that's how the goose got its name! The stems of the barnacle in particular are a delicacy in southwestern Europe.

Woods Hole, Maine

Woods Hole, Maine

Woods Hole, Maine

Woods Hole, Maine

Woods Hole, Maine

Woods Hole, Maine

Woods Hole, Maine

Woods Hole, Maine

Geographical Range: Cosmopolitan in the open sea. Often found washed up on the beach on the open coast; on our shores not usually washed up south of Point Conception, CA.

Biology/Natural History: This seems to be the most common pelagic gooseneck barnacle along the Washington coast. The opening of this barnacle is lined with beautiful scarlet tissue. The peduncle is purplish-brown. Reaches sexual maturity when the capitulum is about 2.5 cm across. Fertilization is internal. Young are brooded in a mass attached to the mantle wall. Nauplii are released after about a week.

This gooseneck barnacle has a flattened capitulum with only 5 plates. Attaches to floating objects such as driftwood, glass, or plastic. It has no notch on the side that borders the scutum. The plates are covered with fine striations.

Depth Range: Shallow pelagic, usually within a meter of the surface attached to a floating object.

Pelagic, attached to floating wood and debris.

How to Distinguish from Similar Species: Mitella polymerus, the other goosneck barnacle commonly found intertidally, has more than 10 plates in the capitulum and attaches to rocks. Lepas pacifica has a notch on the side of the capitulum that borders the scutum. Lepas hilli has smooth plates and 3 or more filamentous growths from the base of the first cirri.

Lepas anatifera, commonly known as the pelagic gooseneck barnacle or smooth gooseneck barnacle, is a species of barnacle in the family Lepadidae. These barnacles are found, often in large numbers, attached by their flexible stalks to floating timber, the hulls of ships, piers, pilings, seaweed, and various sorts of flotsam.