40 Fun Facts About Barnacles

A rock barnacle spends its whole adult life glued upside down to the shore by which part of its body?

Its forehead is where the cement glands sit, at the base of the first pair of antennae. A larva picks the spot, glues itself down and never moves again.

A feeding barnacle combs food from the water with feathery cirri, which are modified versions of which body parts?

Legs are what a barnacle feeds with: six pairs of them, curled and fringed with hairs, sweep out through the top of the shell and rake food towards the mouth.

For its body size, a barnacle has the longest what of any known animal?

Penis length in barnacles can reach eight times the body length, the largest ratio of any known animal. It stretches out to fertilise neighbours cemented nearby.

Which Victorian naturalist spent eight years dissecting barnacles and then declared he hated them as no man ever had?

Charles Darwin's barnacle monographs won him the Royal Society's Royal Medal in 1853. He worked on them at home so intently that his young son assumed every father did the same.

Barnacles were classed as molluscs until their swimming larvae revealed that they belong to which animal group?

Crustaceans is the right group, which makes barnacles cousins of shrimp and lobsters. John Vaughan Thompson showed it in 1830 by watching the free-swimming young settle and turn into adults.

Which ocean giant, famous for its long knobbly flippers, can carry as much as 450 kg of barnacles on its skin?

Humpback whale skin suits one barnacle species so well that a single animal can carry 450 kg of them. The passengers feed for free as their host swims through the sea.

Goose barnacles called percebes, picked by hand from wave-battered rocks, are a costly delicacy in which two countries?

Spain and Portugal prize percebes so highly that harvesters called percebeiros risk their lives on surf-pounded cliffs to gather them. The name comes from Latin words for thumb and foot.

Which Pirates of the Caribbean villain commands a barnacle-encrusted crew who slowly become part of their ship?

Davy Jones captains the Flying Dutchman, whose cursed sailors grow shells and coral until the hull absorbs them. Bill Nighy played him through motion capture.

In the children's series Octonauts, the crew's leader Captain Barnacles is which kind of animal?

Polar bear Captain Barnacles is strong enough to lift a giant clam, yet one episode reveals that he is claustrophobic. His crewmates include Kwazii the cat and a penguin medic called Peso.

Barnacle geese were once thought to grow from barnacles because nobody in Europe saw them nest; where do they breed?

The Arctic is where barnacle geese raise their young each summer, far from the European shores where they winter. The word barnacle named the bird first and the shellfish only from the 1580s.

Barnacle Boy is the grumpy sidekick of which elderly superhero in SpongeBob SquarePants?

Mermaid Man and his partner were voiced by Ernest Borgnine and Tim Conway, who had starred together in the 1960s sitcom McHale's Navy. The pair send up the Batman TV series of the same decade.

The commonest barnacles, which grow their cone-shaped shells straight onto rock, are named after which tree nut?

Acorn barnacles keep the same shell for life: the animal inside moults its skin as it grows, but the hard plates are never shed and simply gain new material.

A shore barnacle shuts the four movable plates of its door at which time, to keep from drying out?

Low tide leaves shore barnacles in the open air, so they close up to hold in moisture. As the sea returns, the door reopens and the feeding limbs come out.

In the 18th century the Royal Navy began nailing thin sheets of which metal over hulls to keep barnacles off?

Copper sheathing was first fitted to a whole hull on the frigate HMS Alarm in 1761, chiefly to stop shipworm boring into the timbers. The metal's poison was also expected to slow barnacle growth.

The parasitic barnacle Sacculina sterilises which animals and makes the males behave like egg-carrying females?

Crabs infected by Sacculina are taken over from within by root-like threads. The host stops breeding and instead tends the parasite's young, fanning them into the sea as if they were its own.

The giant barnacle picoroco is an essential ingredient of curanto, a pit-cooked seafood feast from which country?

Chile harvests the picoroco along its coast, where the barnacle grows as tall as 30 cm. In a curanto it is cooked over heated stones with clams, mussels, meat and potatoes.

Some scientists think a coat of barnacles helps certain baleen whales fight off bites from which ocean predator?

Orcas may think twice about biting a flipper studded with sharp shells. Whales built to fight seem to carry the heaviest barnacle loads, while faster species that flee stay almost clean.

The Barnacle is a yellow parking enforcement device that attaches to which part of an offending car?

Windshield suction holds the Barnacle in place and blocks the driver's view until the fine is paid. Students in Oklahoma beat it within days, using defoggers and credit cards.

Goose barnacles, unlike the cone-shaped kind that sit flat on rock, attach themselves to surfaces by means of what?

A fleshy stalk anchors each goose barnacle, and in ocean-drifting species it can be more than half a metre long. It is also the part that diners eat.

The shell-less barnacle Anelasma feeds through root-like tendrils sunk into the flesh of which deep-sea hosts?

Sharks such as lanternsharks and dogfish carry Anelasma half-buried in their skin. Its feeding limbs have shrunk to useless stubs, and it seems to stop its hosts from maturing sexually.

Barnacle cement inspired MIT researchers to make a medical paste that can do what within about 15 seconds?

To stop bleeding, the paste forms a tight seal on wet tissue, much as a barnacle grips a wave-washed rock. The animal's own fast-curing cement is among the most powerful natural glues known.

What is the sailors' term for the build-up of barnacles and weed that slows a ship's hull through the water?

Fouling by barnacles can raise a ship's drag by as much as 60 percent and its fuel use by 40 percent, on a US Navy estimate. Some boaters call the culprits crusty foulers.

Before dry docks, crews beached a sailing ship and heaved it onto its side to scrape off barnacles, a job called what?

Careening takes its name from carina, the Latin for a keel. With the ship hauled over on a beach, each side of the bottom could be scraped and repaired in turn.

The giant barnacle of the northeast Pacific, Balanus nubilus, contains the largest known examples of what?

Muscle fibres bigger than any other animal's sit inside this barnacle, which is why laboratories use it to study how muscles work. Sea stars prey on it, and small octopuses shelter in its empty shells.

Which sea snails are among the commonest predators of barnacles, able to grind through the shell plates?

Whelks such as the dog whelk can also prise the plates apart with a proboscis and finish a barnacle in about a day. Limpets and mussels are rivals for space on the rock, not predators.

Which sense, served by sensitive hairs on the limbs, appears to be the main one a barnacle relies on?

Touch does most of the work, but a barnacle also has three simple eyes that can tell light from dark. When a shadow falls across it, it stops feeding and snaps shut.

Barnacle Bill, named for its barnacle-like bumps, was the first Martian rock analysed by which small Pathfinder rover?

Sojourner took ten hours to analyse Barnacle Bill with its X-ray spectrometer on the third day of the mission. Early readings suggested a volcanic rock called andesite.

Believing barnacle geese grew from barnacles, not eggs, some medieval clergy ate them as fish during which season?

Lent was a meatless season, so a bird thought not to be born of flesh looked like a handy loophole. Gerald of Wales criticised Irish clergy for the habit in the 12th century.

Which actor played a seasick naval officer and six of his ancestors in the 1957 Ealing comedy Barnacle Bill?

Alec Guinness made the film only as a favour to its director and later called it wretched. It was the last of the Ealing comedies and was released in America as All at Sea.

The drinking song Barnacle Bill the Sailor was the recurring theme for which character in the first Popeye cartoon?

Bluto stomped on screen to the tune in 1933, and Fleischer Studios came back to it two years later for a Popeye mock operetta called Beware of Barnacle Bill.

The stalked barnacle Dosima fascicularis, which drifts across open oceans, is the only barnacle known to do what?

To make its own float, this barnacle secretes a gas-filled cement with a texture like polystyrene foam. Adults also raft on feathers, tar pellets, plastic and even apples.

Fossil whale barnacles, shed onto the seabed long ago, help scientists trace what about ancient whales?

Migration routes and breeding grounds show up as scatters of shed shells on the seabed. Whale barnacles live for only about a year, so they fall away along the journey.

A barnacle's last larval stage does not feed and exists only to find a place to settle; what is it called?

Cyprid larvae test surfaces with their antennules for days or weeks, and many prefer to settle beside other barnacles. As their energy runs down, they become less choosy.

Which Holy Roman Emperor and keen falconer examined barnacles himself and found no sign of any bird inside?

Frederick II sent envoys north to fetch the barnacle-covered timbers and saw nothing bird-like on them. He guessed the tale arose because nobody knew where the geese nested.

Ship bottoms are traditionally painted which colour, a legacy of early barnacle-repelling paints?

Red was the natural colour of the metal-based paints first used to poison barnacles and weed, and the look stuck. Modern hull paints still rely on similar biocides.

The whale barnacle Coronula diadema, as its Latin name suggests, has a shell that resembles what?

A crown is what the shell resembles at first, though it grows more barrel-like with age. Large ones stand 5 cm tall, and a goose barnacle species often settles on top of them.

A 1930 Fleischer cartoon named after the sailor song Barnacle Bill featured which flapper character?

Betty Boop starred in the animated short, the first of several screen outings for the song's hero. Feature films named after him followed in 1935, 1941 and 1957.

Goose barnacles, long known on sea turtles, were first found on which other reptile off Mexico's Pacific coast?

American crocodile hides usually stay clear of them because the animals keep to mangroves and estuaries. The size of the barnacles showed this one had spent at least a week at sea.

Which sea mammals, crusted with their own barnacle species, have been seen rubbing on gravelly seabeds to dislodge them?

Gray whales carry a barnacle found almost always on this one host, which embeds itself deep in the skin. Clusters crowd the head and back.

The Australasian barnacle Austrominius modestus was first seen in British waters during which conflict?

World War II shipping is the likely carrier: the barnacle was first seen in Chichester Harbour and had reached Shetland by 1978. It matures in its first season, which helps it outpace native species.