barnacle

bar·na·cle

B0081800 (bär′nə-kəl)n.1. Any of various marine crustaceans of the subclass Cirripedia that in the adult stage form a hard shell which remains attached to submerged surfaces such as rocks and ships' hulls, and that have feathery appendages used for filter feeding.2. The barnacle goose.

[Middle English, barnacle goose, from Old French bernacle, from Medieval Latin bernacula, diminutive of bernaca, of unknown origin.]

bar′na·cled adj.Word History: The word barnacle is known from as far back as the early 13th century. At that time it did not refer to the crustacean, as it does today, but only to the species of waterfowl now more often known as the barnacle goose; more than 300 years went by before barnacle was used to refer to the crustacean. One might well wonder what the connection between these two creatures is. The answer lies in natural history. Until fairly recent times, it was widely believed that certain animals were engendered spontaneously from particular substances. Maggots, for instance, were believed to be generated from rotting meat. Because the barnacle goose breeds in the Arctic, no one at that time had ever witnessed the bird breeding; as a result, it was thought to be spontaneously generated from trees along the shore, or from rotting wood. Wood that has been in the ocean for any length of time is often dotted with barnacles, and it was natural for people to believe that the crustaceans were also engendered directly from the wood, like the geese. In fact, as different as the two creatures might appear to us, they share a similar trait: barnacles have long feathery cirri that are reminiscent of a bird's plumage. This led one writer in 1678 to comment on the "multitudes of little Shells; having within them little Birds perfectly shap'd, supposed to be Barnacles [that is, barnacle geese]." In popular conception the two creatures were thus closely linked. Over time the crustacean became the central referent of the word, and the bird was called the barnacle goose for clarity, making barnacle goose an early example of what we now call a retronym.

barnacle

(ˈbɑːnəkəl) n1. (Animals) any of various marine crustaceans of the subclass Cirripedia that, as adults, live attached to rocks, ship bottoms, etc. They have feathery food-catching cirri protruding from a hard shell. See acorn barnacle, goose barnacle2. a person or thing that is difficult to get rid of[C16: related to Late Latin bernicla, of obscure origin] ˈbarnacled adj

bar•na•cle

(ˈbɑr nə kəl)

n. 1. any marine crustacean of the subclass Cirripedia, having a shell made up of separate plates, being either stalked (goose barnacle) and attaching itself to ship bottoms and floating timber, or stalkless (rock barnacle). 2. one that clings tenaciously. [1580–85; perhaps a conflation of barnacle barnacle goose with Cornish brennyk limpet (or Celtic cognates)] bar′na•cled, adj.

bar·na·cle

(bär′nə-kəl) Any of various small, hard-shelled crustaceans that live in the ocean and attach themselves to underwater objects, such as rocks and the bottoms of ships.

Thesaurus

Noun	1.	barnacle - marine crustaceans with feathery food-catching appendages; free-swimming as larvae; as adults form a hard shell and live attached to submerged surfacescirriped, cirripedecrustacean - any mainly aquatic arthropod usually having a segmented body and chitinous exoskeletonCirripedia, subclass Cirripedia - barnaclesacorn barnacle, Balanus balanoides, rock barnacle - barnacle that attaches to rocks especially in intertidal zonesgoose barnacle, gooseneck barnacle, Lepas fascicularis - stalked barnacle that attaches to ship bottoms or floating timbers
	2.	barnacle - European goose smaller than the brant; breeds in the far northbarnacle goose, Branta leucopsisgoose - web-footed long-necked typically gregarious migratory aquatic birds usually larger and less aquatic than ducksBranta, genus Branta - wild geese

Translations

藤壶

barnacle

(ˈbaːnəkl) noun a kind of small shellfish that sticks to rocks and the bottoms of ships. 藤壶

barnacle

barnacle,

common name of the sedentary crustaceancrustacean
, primarily aquatic arthropod of the subphylum Crustacea. Most of the 44,000 crustacean species are marine, but there are many freshwater forms. The few groups that inhabit terrestrial areas have not been particularly successful in an evolutionary sense; most require
..... Click the link for more information. animals constituting the infraclass Cirripedia. Barnacles are exclusively marine and are quite unlike any other crustacean because of the permanently attached, or sessile, mode of existence for which they are highly modified. Typical barnacles attach to the substrate by means of an exceedingly adhesive cement, produced by a cement gland, and secrete a shell, or carapace, of calcareous (limestone) plates, around themselves. Colonies of such barnacles form conspicuous encrustations on wharves, boats, pilings, and rocky shores. They range in length from under 1 in. (2.5 cm) to 30 in. (75 cm). Their shells are commonly yellow, orange, red, pink, or purple, sometimes with striped patterns. Because of their sedentary life and enclosing shells, barnacles were thought to be mollusks until 1830, when their larval stages were discovered. Much of what is known about barnacles is the result of research by Charles Darwin, who published a monumental work on the subject in the 1840s.

Shelled and Shell-less Barnacles

Barnacles with a calcareous shell (order Thoracica) include the gooseneck barnacles, which are attached to the substrate by means of a stalk, or peduncle, and the acorn, or rock, barnacles, which are attached directly to the substrate. The stalk of gooseneck barnacles is simply an elongation of the attached end of the animal's body. In some gooseneck barnacles the stalk as well as the body is covered by calcareous plates; in others it is a naked leathery or horny structure. A gooseneck barnacle found in large numbers on ships and pilings is Lepas, which has a leathery stalk and flattened shell and looks like a small clam attached by its siphon.

Balanus is an acorn barnacle commonly found on rocks; it has a thick conical shell attached at its wide base, with an opening at the top. As in many of the acorn barnacles, the plates of the surrounding carapace form an impenetrable wall, and the opening is equipped with two movable plates that can be pulled down to close off the body completely.

In both gooseneck and acorn barnacles the feathery legs of the animal may sometimes be seen protruding through the carapace opening. When the animal feeds, these jointed legs, called cirri, sweep organic particles and minute planktonic organisms toward the mouth, which is located deeper inside the shell. The attached end of the animal is its anterior, or head region: the barnacle has been described as a shrimplike animal standing on its head in a limestone house and kicking food into its mouth with its feet. Barnacles lack gills; gas exchange occurs through the cirri and the body wall. Some shelled barnacles are commensal, attaching themselves to living animals such as whales, porpoises, turtles, crustaceans, and echinoderms. The gooseneck barnacle Conchoderma may be found growing on the acorn barnacle Coronula, which grows on the skin of whales.

Besides the shelled barnacles there are naked barnacles (orders Ascothoracica and Rhizocephala), which live on, and in some cases parasitize, other invertebrate animals. There are also shell-less boring barnacles (order Acrothoracica), which live inside holes that they drill in shells and corals.

Reproduction

Although nearly all other crustaceans have separate sexes, most barnacles are hermaphroditeshermaphrodite
, animal or plant that normally possesses both male and female reproductive systems, producing both eggs and sperm. Many plants, including most flowering plants (angiosperms), are hermaphroditic, or monoecious; in these, male and female reproductive structures are
..... Click the link for more information. , with cross-fertilization between adjacent individuals being the rule. Some species, however, have dwarf males, which are parasitic on female or hermaphroditic individuals. The fertilized egg develops into a free-swimming larva, called a nauplius larva, of the basic crustacean type, with paired antennae. This form then molts to become a cypris, or bivalve, larva, which eventually attaches itself to a suitable substrate by its first pair of antennae and undergoes metamorphosismetamorphosis
[Gr.,=transformation], in zoology, term used to describe a form of development from egg to adult in which there is a series of distinct stages. Many insects, amphibians, mollusks, crustaceans, and fishes undergo metamorphosis, which may involve a change in habitat,
..... Click the link for more information. into an adult.

Economic Significance

Barnacles are economically significant because they settle on ship hulls and harbor installations; the resulting encrustation of the ships greatly increases friction, diminishing speed and increasing fuel consumption. Ships are treated with plastic coating or with antifouling paints containing copper or mercury to prevent or diminish encrustation.

Classification

Barnacles are classified in the phylum ArthropodaArthropoda
[Gr.,=jointed feet], largest and most diverse animal phylum. The arthropods include crustaceans, insects, centipedes, millipedes, spiders, scorpions, and the extinct trilobites.
..... Click the link for more information. , subphylum Crustacea, class Maxillopoda, infraclass Cirripedia.

barnacle

[′bär·nə·kəl] (engineering) A nodelike deposit that occurs on the surface of a heat exchanger tube or an evaporating device and has a semigranular outer shell bonded to the fouled surface, enclosing a slurry of putrefying organisms. (invertebrate zoology) The common name for a number of species of crustaceans which compose the subclass Cirripedia.

barnacle

any of various marine crustaceans of the subclass Cirripedia that, as adults, live attached to rocks, ship bottoms, etc. They have feathery food-catching cirri protruding from a hard shell

barnacle

bar·na·cle

barnacle

bar•na•cle

bar·na·cle

barnacle

barnacle

barnacle,

Shelled and Shell-less Barnacles

Reproduction

Economic Significance

Classification

barnacle

barnacle

barnacle

barnacle

barnacle

Synonyms for barnacle

noun marine crustaceans with feathery food-catching appendages

Synonyms

Related Words

noun European goose smaller than the brant

Synonyms

Related Words