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Barnacle

Barnacles are a type of arthropod constituting the subclass Cirripedia in the subphylum Crustacea,[1] and are hence related to crabs and lobsters. Barnacles are exclusively marine, and tend to live in shallow and tidal waters, typically in erosive settings. Around 1,000 barnacle species are currently known.[2]

Barnacle
Temporal range: Carboniferous–Recent
Chthamalus stellatus
Scientific classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Arthropoda
Class: Thecostraca
Subclass: Cirripedia
Burmeister, 1834
Infraclasses
Synonyms
  • Thyrostraca
  • Cirrhopoda
  • Cirrhipoda
  • Cirrhipedia

They are sessile (nonmobile) and most are suspension feeders, but those in infraclass Rhizocephala are highly specialized parasites on other crustaceans. They have four nektonic (active swimming) larval stages.

Description edit

 
Whale barnacles attached to the throat of a humpback whale
 
Barnacles on a boat propeller.

Barnacles are encrusters, attaching themselves temporarily to a hard substrate or a symbiont such as a whale (whale barnacles), a sea snake (Platylepas ophiophila), or another crustacean, like a crab or a lobster (Rhizocephala). The most common among them, "acorn barnacles" (Sessilia), are sessile where they grow their shells directly onto the substrate.[3] Pedunculate barnacles (goose barnacles and others) attach themselves by means of a stalk.[3]

Attachment edit

Free-living barnacles are attached to the substratum by cement glands that form the base of the first pair of antennae; in effect, the animal is fixed upside down by means of its forehead. In some barnacles, the cement glands are fixed to a long, muscular stalk, but in most they are part of a flat membrane or calcified plate. These glands secrete a type of natural quick cement made of complex protein bonds (polyproteins) and other trace components like calcium.[4]: 2–3  This natural cement is able to withstand a pulling strength of 5,000 pounds-force per square inch (30,000 kilopascals; 400 kilograms-force per square centimetre) and a sticking strength of 22–60 pounds-force per square inch (200–400 kilopascals; 2–4 kilograms-force per square centimetre).[5]

A ring of plates surrounds the body, homologous with the carapace of other crustaceans. These consist of the rostrum, two lateral plates, two carinolaterals, and a carina.[6] In sessile barnacles, the apex of the ring of plates is covered by an operculum, which may be recessed into the carapace. The plates are held together by various means, depending on species, in some cases being solidly fused.[citation needed]

Inside body edit

Inside the carapace, the animal lies on its stomach, projecting its limbs downwards. Segmentation is usually indistinct, and the body is more or less evenly divided between the head and thorax, with little, if any, abdomen. Adult barnacles have few appendages on their heads, with only a single, vestigial pair of antennae, attached to the cement gland. The eight pairs of thoracic limbs are referred to as "cirri" which are feathery and very long. The cirri extend to filter food, such as plankton, from the water and move it towards the mouth.[5]

Barnacles have no true heart, although a sinus close to the esophagus performs a similar function, with blood being pumped through it by a series of muscles.[7] The blood vascular system is minimal. Similarly, they have no gills, absorbing oxygen from the water through their limbs and the inner membrane of their carapaces. The excretory organs of barnacles are maxillary glands.[citation needed]

The main sense of barnacles appears to be touch, with the hairs on the limbs being especially sensitive. The adult also has three photoreceptors (ocelli), one median and two lateral. These photoreceptors record the stimulus for the barnacle shadow reflex, where a sudden decrease in light causes cessation of the fishing rhythm and closing of the opercular plates.[8] The photoreceptors are likely only capable of sensing the difference between light and dark.[9] This eye is derived from the primary naupliar eye.[10]

Etymology edit

The word "barnacle" is attested in the early 13th century as "bernekke" and originally referred to a species of goose. Because the full life cycles of both barnacles and geese was unknown at the time, (geese spend their breeding seasons in the Arctic) a folktale emerged that geese hatched from barnacles. It was not applied strictly to the invertebrate until the 1580s. The ultimate meaning of the word "barnacle" is unknown.[11][12]

Life cycle edit

Barnacles have two distinct larval stages, the nauplius and the cyprid, before developing into a mature adult.

Nauplius edit

 
Nauplius larva of Elminius modestus
 
Nauplius larva of a barnacle with fronto-lateral horns[13]

A fertilised egg hatches into a nauplius: a one-eyed larva comprising a head and a telson, without a thorax or abdomen. This undergoes six moults, passing through five instars, before transforming into the cyprid stage. Nauplii are typically initially brooded by the parent, and released after the first moult as larvae that swim freely using setae.[14][15]

Cyprid edit

The cyprid larva is the last larval stage before adulthood. In Rhizocephala and Thoracica an abdomen is absent in this stage, but the y-cyprids (post‐naupliar instar) has three distinct abdominal segments.[16] It is not a feeding stage; its role is to find a suitable place to settle, since the adults are sessile.[14] The cyprid stage lasts from days to weeks. It explores potential surfaces with modified antennules; once it has found a potentially suitable spot, it attaches head-first using its antennules and a secreted glycoproteinous substance. Larvae assess surfaces based upon their surface texture, chemistry, relative wettability, color, and the presence or absence and composition of a surface biofilm; swarming species are also more likely to attach near other barnacles.[17] As the larva exhausts its finite energy reserves, it becomes less selective in the sites it selects. It cements itself permanently to the substrate with another proteinaceous compound, and then undergoes metamorphosis into a juvenile barnacle.[17]

Adult edit

Typical acorn barnacles develop six hard calcareous plates to surround and protect their bodies. For the rest of their lives, they are cemented to the substrate, using their feathery legs (cirri) to capture plankton.

Once metamorphosis is over and they have reached their adult form, barnacles continue to grow by adding new material to their heavily calcified plates. These plates are not moulted; however, like all ecdysozoans, the barnacle itself will still moult its cuticle.[18]

Sexual reproduction edit

Most barnacles are hermaphroditic, although a few species are gonochoric or androdioecious. The ovaries are located in the base or stalk, and may extend into the mantle, while the testes are towards the back of the head, often extending into the thorax. Typically, recently moulted hermaphroditic individuals are receptive as females. Self-fertilization, although theoretically possible, has been experimentally shown to be rare in barnacles.[19][20]

The sessile lifestyle of barnacles makes sexual reproduction difficult, as the organisms cannot leave their shells to mate. To facilitate genetic transfer between isolated individuals, barnacles have extraordinarily long penises⁠. Barnacles probably have the largest penis to body size ratio of the animal kingdom,[19] up to eight times their body length.[21]

Barnacles can also reproduce through a method called spermcasting, in which the male barnacle releases his sperm into the water and females pick it up and fertilise their eggs.[22][23]

The Rhizocephala superorder used to be considered hermaphroditic, but it turned out that its males inject themselves into the female's body, degrading to the condition of nothing more than sperm-producing cells.[24]

Ecology edit

Semibalanus balanoides feeding

Most barnacles are suspension feeders; they dwell continually in their shells, which are usually constructed of six plates,[3] and reach into the water column with modified legs. These feathery appendages beat rhythmically to draw plankton and detritus into the shell for consumption.[25]

Other members of the class have quite a different mode of life. For example, members of the superorder Rhizocephala, including the genus Sacculina, are parasitic and live within crabs.[26]

Although they have been found at water depths to 600 m (2,000 ft),[3] most barnacles inhabit shallow waters, with 75% of species living in water depths less than 100 m (300 ft),[3] and 25% inhabiting the intertidal zone.[3] Within the intertidal zone, different species of barnacles live in very tightly constrained locations, allowing the exact height of an assemblage above or below sea level to be precisely determined.[3]

Since the intertidal zone periodically desiccates, barnacles are well adapted against water loss. Their calcite shells are impermeable, and they possess two plates which they can slide across their apertures when not feeding. These plates also protect against predation.[27]

One group of stalked barnacles have adapted to a rafting lifestyle, where they are drifting around close to the water's surface. They will colonize every floating object, such as driftwood, and like some non-stalked barnacles, also attach themselves to marine animals. The species most specialized for this lifestyle is Dosima fascicularis, which secretes a gas-filled cement that makes it float at the surface.[28]

Barnacles are displaced by limpets and mussels, which compete for space. They also have numerous predators.[3] They employ two strategies to overwhelm their competitors: "swamping" and fast growth. In the swamping strategy, vast numbers of barnacles settle in the same place at once, covering a large patch of substrate, allowing at least some to survive in the balance of probabilities.[3] Fast growth allows the suspension feeders to access higher levels of the water column than their competitors, and to be large enough to resist displacement; species employing this response, such as the aptly named Megabalanus, can reach 7 cm (3 in) in length;[3] other species may grow larger still (Austromegabalanus psittacus).

Competitors may include other barnacles, and disputed evidence indicates balanoid barnacles competitively displaced chthalamoid barnacles. Balanoids gained their advantage over the chthalamoids in the Oligocene, when they evolved tubular skeletons, which provide better anchorage to the substrate, and allow them to grow faster, undercutting, crushing, and smothering chthalamoids.[29]

Among the most common predators on barnacles are whelks. They are able to grind through the calcareous exoskeletons of barnacles and feed on the softer inside parts. Mussels also prey on barnacle larvae.[30] Another predator on barnacles is the starfish species Pisaster ochraceus.[31][32]

The anatomy of parasitic barnacles is generally simpler than that of their free-living relatives. They have no carapace or limbs, having only unsegmented sac-like bodies. Such barnacles feed by extending thread-like rhizomes of living cells into their hosts' bodies from their points of attachment.[9]

History of taxonomy edit

 
"Cirripedia" from Ernst Haeckel's Kunstformen der Natur (1904): The crab at the centre is nursing the externa of the parasitic cirripede Sacculina.

Barnacles were originally classified by Linnaeus and Cuvier as Mollusca, but in 1830 John Vaughan Thompson published observations showing the metamorphosis of the nauplius and cypris larvae into adult barnacles, and noted how these larvae were similar to those of crustaceans. In 1834 Hermann Burmeister published further information, reinterpreting these findings. The effect was to move barnacles from the phylum of Mollusca to Articulata, showing naturalists that detailed study was needed to reevaluate their taxonomy.[33]

Charles Darwin took up this challenge in 1846, and developed his initial interest into a major study published as a series of monographs in 1851 and 1854.[33] Darwin undertook this study, at the suggestion of his friend Joseph Dalton Hooker, to thoroughly understand at least one species before making the generalisations needed for his theory of evolution by natural selection.[34][35] Upon the conclusion of his research, Darwin declared "I hate a barnacle as no man ever did before."[36][35]

The name Cirripedia comes from the Latin words cirritus "curly" from cirrus "curl"[37] and pedis from pes "foot,"[38] the two words together mean "curl-footed."[39][further explanation needed] The study of barnacles is called cirripedology.

Classification edit

Some authorities regard the Cirripedia as a full class or subclass, and the orders listed above are sometimes treated as superorders. In 2001, Martin and Davis placed Cirripedia as an infraclass of Thecostraca and divided it into six orders:[40]

  • Infraclass Cirripedia Burmeister, 1834
    • Superorder Acrothoracica Gruvel, 1905
      • Order Pygophora Berndt, 1907
      • Order Apygophora Berndt, 1907
    • Superorder Rhizocephala Müller, 1862
      • Order Kentrogonida Delage, 1884
      • Order Akentrogonida Häfele, 1911
    • Superorder Thoracica Darwin, 1854

In 2021, Chan et al. elevated Cirripedia to subclass of the class Thecostraca, and the superorders Acrothoracica, Rhizocephala, and Thoracica to infraclass. The updated classification, which now includes 11 orders, has been accepted in the World Register of Marine Species.[41][1]

Fossil record edit

The oldest definitive fossil barnacle is Praelepas from the mid-Carboniferous, around 330-320 million years ago.[42] Older claimed barnacles such as Priscansermarinus from the Middle Cambrian (on the order of 510 to 500 million years ago)[43] do not show clear barnacle morphological traits, though Rhamphoverritor from the Silurian Coalbrookdale Formation of England may represent a stem-group barnacle.[42] Barnacles first radiated and became diverse during the Late Cretaceous. Barnacles underwent a second, much larger radiation beginning during the Neogene (last 23 million years), which continues to present.[42] In part, their poor skeletal preservation is due to their restriction to high-energy environments, which tend to be erosional – therefore it is more common for their shells to be ground up by wave action than for them to reach a depositional setting.

Barnacles can play an important role in estimating paleo-water depths. The degree of disarticulation of fossils suggests the distance they have been transported, and since many species have narrow ranges of water depths, it can be assumed that the animals lived in shallow water and broke up as they were washed down-slope. The completeness of fossils, and nature of damage, can thus be used to constrain the tectonic history of regions.[3]

Relationship with humans edit

Barnacles are of economic consequence, as they often attach themselves to synthetic structures, sometimes to the structure's detriment. Particularly in the case of ships, they are classified as fouling organisms.[44] The number and size of barnacles that cover ships can impair their efficiency by causing hydrodynamic drag. This is not a problem for boats on inland waterways, as barnacles are exclusively marine. The stable isotope signals in the layers of barnacle shells can potentially be used as a forensic tracking method[45] for whales, loggerhead turtles[46] and marine debris, such as shipwrecks or a flaperon suspected to be from Malaysia Airlines Flight 370.[47][48][49]

The flesh of some barnacles is routinely consumed by humans, including Japanese goose barnacles (e.g. Capitulum mitella), and goose barnacles (e.g. Pollicipes pollicipes), a delicacy in Spain and Portugal.[50]

Additionally, the picoroco barnacle is used in Chilean cuisine and is one of the ingredients in curanto seafood stew.

MIT researchers developed an adhesive, inspired by a protein-based bioglue produced by barnacles to firmly attach to rocks, which can form a tight seal to halt bleeding within about 15 seconds of application.[51]

See also edit

References edit

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  2. ^ Walters, Martin; Johnson, Jinny (2007). The World of Animals. Bath, Somerset: Parragon. ISBN 978-1-4054-9926-2.[page needed]
  3. ^ a b c d e f g h i j k P. Doyle; A. E. Mather; M. R. Bennett; A. Bussell (1997). "Miocene barnacle assemblages from southern Spain and their palaeoenvironmental significance". Lethaia. 29 (3): 267–274. doi:10.1111/j.1502-3931.1996.tb01659.x.
  4. ^ Xu, Zhenzhen; Liu, Zhongcheng; Zhang, Chao; Xu, Donggang (October 2022). "Advance in barnacle cement with high underwater adhesion". Journal of Applied Polymer Science. 139 (37): 1–12. doi:10.1002/app.52894. S2CID 251335952.
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  9. ^ a b Barnes, Robert D. (1982). Invertebrate Zoology. Holt-Saunders International. pp. 694–707. ISBN 978-0-03-056747-6.
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  35. ^ a b van Wyhe, John (2007-05-22). "Mind the gap: did Darwin avoid publishing his theory for many years?". Notes and Records of the Royal Society. 61 (2): 177–205. doi:10.1098/rsnr.2006.0171. ISSN 0035-9149. S2CID 202574857.
  36. ^ Bromham, Lindell (2020-10-01). "Comparability in evolutionary biology: The case of Darwin's barnacles". Linguistic Typology. 24 (3): 427–463. doi:10.1515/lingty-2020-2056. hdl:1885/274303. ISSN 1613-415X. S2CID 222319487.
  37. ^ Lewis, Charlton T.; Short, Charles (1879). "cirrus". A Latin Dictionary. Perseus Digital Library.
  38. ^ Lewis, Charlton T.; Short, Charles (1879). "lavo". A Latin Dictionary. Perseus Digital Library.
  39. ^ Concise Oxford English Dictionary (10th ed.). Oxford University Press. 2002. p. 260. ISBN 0-19-860572-2.
  40. ^ Martin, Joel W.; Davis, George E. (2001). An Updated Classification of the Recent Crustacea. CiteSeerX 10.1.1.79.1863.[page needed]
  41. ^ Chan, Benny K. K.; Dreyer, Niklas; Gale, Andy S.; Glenner, Henrik; et al. (2021). "The evolutionary diversity of barnacles, with an updated classification of fossil and living forms". Zoological Journal of the Linnean Society. 193 (3): 789–846. doi:10.1093/zoolinnean/zlaa160.
  42. ^ a b c Chan, Benny K K; Dreyer, Niklas; Gale, Andy S; Glenner, Henrik; Ewers-Saucedo, Christine; Pérez-Losada, Marcos; Kolbasov, Gregory A; Crandall, Keith A; Høeg, Jens T (2021-02-25). "The evolutionary diversity of barnacles, with an updated classification of fossil and living forms". Zoological Journal of the Linnean Society. 193 (zlaa160): 789–846. doi:10.1093/zoolinnean/zlaa160. ISSN 0024-4082.
  43. ^ B. A. Foster & J. S. Buckeridge (1987). Barnacle palaeontology. pp. 41–63. In A. J. Southward (ed.), 1987.
  44. ^ . Newcastle University. Archived from the original on June 5, 2009. Retrieved January 15, 2010.
  45. ^ Pearson, Ryan M.; van de Merwe, Jason P.; Gagan, Michael K.; Connolly, Rod M. (2020). "Unique Post-telemetry Recapture Enables Development of Multi-Element Isoscapes From Barnacle Shell for Retracing Host Movement". Frontiers in Marine Science. 7. doi:10.3389/fmars.2020.00596. hdl:10072/395516. ISSN 2296-7745.
  46. ^ Pearson, Ryan M.; van de Merwe, Jason P.; Gagan, Michael K.; Limpus, Colin J.; Connolly, Rod M. (25 April 2019). "Distinguishing between sea turtle foraging areas using stable isotopes from commensal barnacle shells". Scientific Reports. 9 (1): 6565. Bibcode:2019NatSR...9.6565P. doi:10.1038/s41598-019-42983-4. PMC 6483986. PMID 31024029.
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  49. ^ Pearson, Ryan M.; van de Merwe, Jason P.; Connolly, Rod M. (2020). "Global oxygen isoscapes for barnacle shells: Application for tracing movement in oceans". Science of the Total Environment. 705: 135782. Bibcode:2020ScTEn.705m5782P. doi:10.1016/j.scitotenv.2019.135782. ISSN 0048-9697. PMID 31787294. S2CID 208536416.
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Further reading edit

External links edit

barnacle, other, uses, disambiguation, type, arthropod, constituting, subclass, cirripedia, subphylum, crustacea, hence, related, crabs, lobsters, exclusively, marine, tend, live, shallow, tidal, waters, typically, erosive, settings, around, barnacle, species,. For other uses see Barnacle disambiguation Barnacles are a type of arthropod constituting the subclass Cirripedia in the subphylum Crustacea 1 and are hence related to crabs and lobsters Barnacles are exclusively marine and tend to live in shallow and tidal waters typically in erosive settings Around 1 000 barnacle species are currently known 2 BarnacleTemporal range Carboniferous Recent PreꞒ Ꞓ O S D C P T J K Pg NChthamalus stellatusScientific classificationDomain EukaryotaKingdom AnimaliaPhylum ArthropodaClass ThecostracaSubclass CirripediaBurmeister 1834InfraclassesAcrothoracica Gruvel 1905 Rhizocephala Muller 1862 Thoracica Darwin 1854 SynonymsThyrostraca Cirrhopoda Cirrhipoda CirrhipediaThey are sessile nonmobile and most are suspension feeders but those in infraclass Rhizocephala are highly specialized parasites on other crustaceans They have four nektonic active swimming larval stages Contents 1 Description 1 1 Attachment 1 2 Inside body 2 Etymology 3 Life cycle 3 1 Nauplius 3 2 Cyprid 3 3 Adult 3 4 Sexual reproduction 4 Ecology 5 History of taxonomy 6 Classification 7 Fossil record 8 Relationship with humans 9 See also 10 References 10 1 Further reading 11 External linksDescription edit nbsp Whale barnacles attached to the throat of a humpback whale nbsp Barnacles on a boat propeller Barnacles are encrusters attaching themselves temporarily to a hard substrate or a symbiont such as a whale whale barnacles a sea snake Platylepas ophiophila or another crustacean like a crab or a lobster Rhizocephala The most common among them acorn barnacles Sessilia are sessile where they grow their shells directly onto the substrate 3 Pedunculate barnacles goose barnacles and others attach themselves by means of a stalk 3 Attachment edit Free living barnacles are attached to the substratum by cement glands that form the base of the first pair of antennae in effect the animal is fixed upside down by means of its forehead In some barnacles the cement glands are fixed to a long muscular stalk but in most they are part of a flat membrane or calcified plate These glands secrete a type of natural quick cement made of complex protein bonds polyproteins and other trace components like calcium 4 2 3 This natural cement is able to withstand a pulling strength of 5 000 pounds force per square inch 30 000 kilopascals 400 kilograms force per square centimetre and a sticking strength of 22 60 pounds force per square inch 200 400 kilopascals 2 4 kilograms force per square centimetre 5 A ring of plates surrounds the body homologous with the carapace of other crustaceans These consist of the rostrum two lateral plates two carinolaterals and a carina 6 In sessile barnacles the apex of the ring of plates is covered by an operculum which may be recessed into the carapace The plates are held together by various means depending on species in some cases being solidly fused citation needed Inside body edit Inside the carapace the animal lies on its stomach projecting its limbs downwards Segmentation is usually indistinct and the body is more or less evenly divided between the head and thorax with little if any abdomen Adult barnacles have few appendages on their heads with only a single vestigial pair of antennae attached to the cement gland The eight pairs of thoracic limbs are referred to as cirri which are feathery and very long The cirri extend to filter food such as plankton from the water and move it towards the mouth 5 Barnacles have no true heart although a sinus close to the esophagus performs a similar function with blood being pumped through it by a series of muscles 7 The blood vascular system is minimal Similarly they have no gills absorbing oxygen from the water through their limbs and the inner membrane of their carapaces The excretory organs of barnacles are maxillary glands citation needed The main sense of barnacles appears to be touch with the hairs on the limbs being especially sensitive The adult also has three photoreceptors ocelli one median and two lateral These photoreceptors record the stimulus for the barnacle shadow reflex where a sudden decrease in light causes cessation of the fishing rhythm and closing of the opercular plates 8 The photoreceptors are likely only capable of sensing the difference between light and dark 9 This eye is derived from the primary naupliar eye 10 Etymology editSee also Barnacle goose myth The word barnacle is attested in the early 13th century as bernekke and originally referred to a species of goose Because the full life cycles of both barnacles and geese was unknown at the time geese spend their breeding seasons in the Arctic a folktale emerged that geese hatched from barnacles It was not applied strictly to the invertebrate until the 1580s The ultimate meaning of the word barnacle is unknown 11 12 Life cycle editBarnacles have two distinct larval stages the nauplius and the cyprid before developing into a mature adult Nauplius edit nbsp Nauplius larva of Elminius modestus nbsp Nauplius larva of a barnacle with fronto lateral horns 13 A fertilised egg hatches into a nauplius a one eyed larva comprising a head and a telson without a thorax or abdomen This undergoes six moults passing through five instars before transforming into the cyprid stage Nauplii are typically initially brooded by the parent and released after the first moult as larvae that swim freely using setae 14 15 Cyprid edit The cyprid larva is the last larval stage before adulthood In Rhizocephala and Thoracica an abdomen is absent in this stage but the y cyprids post naupliar instar has three distinct abdominal segments 16 It is not a feeding stage its role is to find a suitable place to settle since the adults are sessile 14 The cyprid stage lasts from days to weeks It explores potential surfaces with modified antennules once it has found a potentially suitable spot it attaches head first using its antennules and a secreted glycoproteinous substance Larvae assess surfaces based upon their surface texture chemistry relative wettability color and the presence or absence and composition of a surface biofilm swarming species are also more likely to attach near other barnacles 17 As the larva exhausts its finite energy reserves it becomes less selective in the sites it selects It cements itself permanently to the substrate with another proteinaceous compound and then undergoes metamorphosis into a juvenile barnacle 17 Adult edit Typical acorn barnacles develop six hard calcareous plates to surround and protect their bodies For the rest of their lives they are cemented to the substrate using their feathery legs cirri to capture plankton Once metamorphosis is over and they have reached their adult form barnacles continue to grow by adding new material to their heavily calcified plates These plates are not moulted however like all ecdysozoans the barnacle itself will still moult its cuticle 18 Sexual reproduction edit Most barnacles are hermaphroditic although a few species are gonochoric or androdioecious The ovaries are located in the base or stalk and may extend into the mantle while the testes are towards the back of the head often extending into the thorax Typically recently moulted hermaphroditic individuals are receptive as females Self fertilization although theoretically possible has been experimentally shown to be rare in barnacles 19 20 The sessile lifestyle of barnacles makes sexual reproduction difficult as the organisms cannot leave their shells to mate To facilitate genetic transfer between isolated individuals barnacles have extraordinarily long penises Barnacles probably have the largest penis to body size ratio of the animal kingdom 19 up to eight times their body length 21 Barnacles can also reproduce through a method called spermcasting in which the male barnacle releases his sperm into the water and females pick it up and fertilise their eggs 22 23 The Rhizocephala superorder used to be considered hermaphroditic but it turned out that its males inject themselves into the female s body degrading to the condition of nothing more than sperm producing cells 24 Ecology edit source source source source source Semibalanus balanoides feedingMost barnacles are suspension feeders they dwell continually in their shells which are usually constructed of six plates 3 and reach into the water column with modified legs These feathery appendages beat rhythmically to draw plankton and detritus into the shell for consumption 25 Other members of the class have quite a different mode of life For example members of the superorder Rhizocephala including the genus Sacculina are parasitic and live within crabs 26 Although they have been found at water depths to 600 m 2 000 ft 3 most barnacles inhabit shallow waters with 75 of species living in water depths less than 100 m 300 ft 3 and 25 inhabiting the intertidal zone 3 Within the intertidal zone different species of barnacles live in very tightly constrained locations allowing the exact height of an assemblage above or below sea level to be precisely determined 3 Since the intertidal zone periodically desiccates barnacles are well adapted against water loss Their calcite shells are impermeable and they possess two plates which they can slide across their apertures when not feeding These plates also protect against predation 27 One group of stalked barnacles have adapted to a rafting lifestyle where they are drifting around close to the water s surface They will colonize every floating object such as driftwood and like some non stalked barnacles also attach themselves to marine animals The species most specialized for this lifestyle is Dosima fascicularis which secretes a gas filled cement that makes it float at the surface 28 Barnacles are displaced by limpets and mussels which compete for space They also have numerous predators 3 They employ two strategies to overwhelm their competitors swamping and fast growth In the swamping strategy vast numbers of barnacles settle in the same place at once covering a large patch of substrate allowing at least some to survive in the balance of probabilities 3 Fast growth allows the suspension feeders to access higher levels of the water column than their competitors and to be large enough to resist displacement species employing this response such as the aptly named Megabalanus can reach 7 cm 3 in in length 3 other species may grow larger still Austromegabalanus psittacus Competitors may include other barnacles and disputed evidence indicates balanoid barnacles competitively displaced chthalamoid barnacles Balanoids gained their advantage over the chthalamoids in the Oligocene when they evolved tubular skeletons which provide better anchorage to the substrate and allow them to grow faster undercutting crushing and smothering chthalamoids 29 Among the most common predators on barnacles are whelks They are able to grind through the calcareous exoskeletons of barnacles and feed on the softer inside parts Mussels also prey on barnacle larvae 30 Another predator on barnacles is the starfish species Pisaster ochraceus 31 32 nbsp Barnacles and limpets compete for space in the intertidal zone nbsp Goose barnacles with their cirri extended for feeding nbsp Underside of large Chesaconcavus sp Miocene showing internal plates in bioimmured smaller barnacles The anatomy of parasitic barnacles is generally simpler than that of their free living relatives They have no carapace or limbs having only unsegmented sac like bodies Such barnacles feed by extending thread like rhizomes of living cells into their hosts bodies from their points of attachment 9 History of taxonomy edit nbsp Cirripedia from Ernst Haeckel s Kunstformen der Natur 1904 The crab at the centre is nursing the externa of the parasitic cirripede Sacculina Barnacles were originally classified by Linnaeus and Cuvier as Mollusca but in 1830 John Vaughan Thompson published observations showing the metamorphosis of the nauplius and cypris larvae into adult barnacles and noted how these larvae were similar to those of crustaceans In 1834 Hermann Burmeister published further information reinterpreting these findings The effect was to move barnacles from the phylum of Mollusca to Articulata showing naturalists that detailed study was needed to reevaluate their taxonomy 33 Charles Darwin took up this challenge in 1846 and developed his initial interest into a major study published as a series of monographs in 1851 and 1854 33 Darwin undertook this study at the suggestion of his friend Joseph Dalton Hooker to thoroughly understand at least one species before making the generalisations needed for his theory of evolution by natural selection 34 35 Upon the conclusion of his research Darwin declared I hate a barnacle as no man ever did before 36 35 The name Cirripedia comes from the Latin words cirritus curly from cirrus curl 37 and pedis from pes foot 38 the two words together mean curl footed 39 further explanation needed The study of barnacles is called cirripedology Classification editSome authorities regard the Cirripedia as a full class or subclass and the orders listed above are sometimes treated as superorders In 2001 Martin and Davis placed Cirripedia as an infraclass of Thecostraca and divided it into six orders 40 Infraclass Cirripedia Burmeister 1834 Superorder Acrothoracica Gruvel 1905 Order Pygophora Berndt 1907 Order Apygophora Berndt 1907 Superorder Rhizocephala Muller 1862 Order Kentrogonida Delage 1884 Order Akentrogonida Hafele 1911 Superorder Thoracica Darwin 1854 Order Pedunculata Lamarck 1818 Order Sessilia Lamarck 1818In 2021 Chan et al elevated Cirripedia to subclass of the class Thecostraca and the superorders Acrothoracica Rhizocephala and Thoracica to infraclass The updated classification which now includes 11 orders has been accepted in the World Register of Marine Species 41 1 Subclass Cirripedia Burmeister 1834 Infraclass Acrothoracica Gruvel 1905 Order Cryptophialida Kolbasov Newman amp Hoeg 2009 Order Lithoglyptida Kolbasov Newman amp Hoeg 2009 Infraclass Rhizocephala Muller 1862 Infraclass Thoracica Darwin 1854 Superorder Phosphatothoracica Gale 2019 Order Iblomorpha Buckeridge amp Newman 2006 Order Eolepadomorpha Chan et al 2021 Superorder Thoracicalcarea Gale 2015 Order Calanticomorpha Chan et al 2021 Order Pollicipedomorpha Chan et al 2021 Order Scalpellomorpha Buckeridge amp Newman 2006 Order Archaeolepadomorpha Chan et al 2021 Order Brachylepadomorpha Withers 1923 Unranked Sessilia Order Balanomorpha Pilsbry 1916 Order Verrucomorpha Pilsbry 1916Fossil record editThe oldest definitive fossil barnacle is Praelepas from the mid Carboniferous around 330 320 million years ago 42 Older claimed barnacles such as Priscansermarinus from the Middle Cambrian on the order of 510 to 500 million years ago 43 do not show clear barnacle morphological traits though Rhamphoverritor from the Silurian Coalbrookdale Formation of England may represent a stem group barnacle 42 Barnacles first radiated and became diverse during the Late Cretaceous Barnacles underwent a second much larger radiation beginning during the Neogene last 23 million years which continues to present 42 In part their poor skeletal preservation is due to their restriction to high energy environments which tend to be erosional therefore it is more common for their shells to be ground up by wave action than for them to reach a depositional setting Barnacles can play an important role in estimating paleo water depths The degree of disarticulation of fossils suggests the distance they have been transported and since many species have narrow ranges of water depths it can be assumed that the animals lived in shallow water and broke up as they were washed down slope The completeness of fossils and nature of damage can thus be used to constrain the tectonic history of regions 3 nbsp Balanus improvisus one of the many barnacle taxa described by Charles Darwin nbsp Miocene Messinian Megabalanus smothered by sand and fossilised nbsp Chesaconcavus a Miocene barnacle from MarylandRelationship with humans editBarnacles are of economic consequence as they often attach themselves to synthetic structures sometimes to the structure s detriment Particularly in the case of ships they are classified as fouling organisms 44 The number and size of barnacles that cover ships can impair their efficiency by causing hydrodynamic drag This is not a problem for boats on inland waterways as barnacles are exclusively marine The stable isotope signals in the layers of barnacle shells can potentially be used as a forensic tracking method 45 for whales loggerhead turtles 46 and marine debris such as shipwrecks or a flaperon suspected to be from Malaysia Airlines Flight 370 47 48 49 The flesh of some barnacles is routinely consumed by humans including Japanese goose barnacles e g Capitulum mitella and goose barnacles e g Pollicipes pollicipes a delicacy in Spain and Portugal 50 Additionally the picoroco barnacle is used in Chilean cuisine and is one of the ingredients in curanto seafood stew MIT researchers developed an adhesive inspired by a protein based bioglue produced by barnacles to firmly attach to rocks which can form a tight seal to halt bleeding within about 15 seconds of application 51 nbsp Barnacles attached to pilings along the Siuslaw River in Oregon nbsp Goose barnacles in a restaurant in MadridSee also editList of Cirripedia generaReferences edit a b Cirripedia World Register of Marine Species Flanders Marine Institute Retrieved 22 August 2021 Walters Martin Johnson Jinny 2007 The World of Animals Bath Somerset Parragon ISBN 978 1 4054 9926 2 page needed a b c d e f g h i j k P Doyle A E Mather M R Bennett A Bussell 1997 Miocene barnacle assemblages from southern Spain and their palaeoenvironmental significance Lethaia 29 3 267 274 doi 10 1111 j 1502 3931 1996 tb01659 x Xu Zhenzhen Liu Zhongcheng Zhang Chao Xu Donggang October 2022 Advance in barnacle cement with high underwater adhesion Journal of Applied Polymer Science 139 37 1 12 doi 10 1002 app 52894 S2CID 251335952 a b What are barnacles Ocean Facts National Ocean Service National Oceanic and Atmospheric Administration 26 February 2021 Retrieved 18 June 2022 Kado Ryusuke Let s learn about the body structure of a barnacle PDF Archived from the original PDF on January 25 2012 Encyclopedia of Life eol org Retrieved 2023 06 07 Gwilliam G F Millecchia R J January 1975 Barnacle photoreceptors Their physiology and role in the control of behavior Progress in Neurobiology 4 211 239 doi 10 1016 0301 0082 75 90002 7 S2CID 53164671 a b Barnes Robert D 1982 Invertebrate Zoology Holt Saunders International pp 694 707 ISBN 978 0 03 056747 6 Lacalli Thurston C September 2009 Serial EM analysis of a copepod larval nervous system Naupliar eye optic circuitry and prospects for full CNS reconstruction Arthropod Structure amp Development 38 5 361 375 doi 10 1016 j asd 2009 04 002 PMID 19376268 barnacle n Online Etymology Dictionary Retrieved 2023 06 28 all the evidence shows that the name was originally applied to the bird which had the marvellous origin not to the shell Oxford English Dictionary 2nd Edition 1989 Perez Losada Marcos Hoeg Jens T Crandall Keith A 17 April 2009 Remarkable convergent evolution in specialized parasitic Thecostraca Crustacea BMC Biology 7 1 15 doi 10 1186 1741 7007 7 15 PMC 2678073 PMID 19374762 a b William A Newman 2007 Cirripedia In Sol Felty Light James T Carlton eds The Light and Smith Manual Intertidal Invertebrates from Central California to Oregon 4th ed University of California Press pp 475 484 ISBN 978 0 520 23939 5 Ruppert Edward E Fox Richard S Barnes Robert D 2004 Invertebrate Zoology 7th ed Cengage Learning p 683 ISBN 978 81 315 0104 7 a href Template Cite book html title Template Cite book cite book a CS1 maint multiple names authors list link Arthropod Systematics Zobodat a b Donald Thomas Anderson 1994 Larval development and metamorphosis Barnacles Structure Function Development and Evolution Springer pp 197 246 ISBN 978 0 412 44420 3 E Bourget 1987 Barnacle shells composition structure and growth pp 267 285 In A J Southward ed 1987 a b Biology of Barnacles Museum Victoria 1996 Archived from the original on February 17 2007 Retrieved April 20 2012 E L Charnov 1987 Sexuality and hermaphroditism in barnacles A natural selection approach pp 89 104 In A J Southward ed 1987 Ewen Callaway 2009 04 07 Penis length isn t everything for barnacle males New Scientist Retrieved 2020 10 03 Bishop J D D Bishop Pemberton A J 2005 The third way spermcast mating in sessile marine invertebrates Integrative and Comparative Biology 46 4 398 406 doi 10 1093 icb icj037 PMID 21672752 Yong Ed 2013 01 15 Poorly Endowed Barnacles Overthrow 150 Year Old Belief National Geographic Retrieved 2021 12 21 Mechanism of Fertilization Plants to Humans edited by Brian Dale Shore life Encarta Encyclopedia 2005 DVD Carl Zimmer 2000 Parasite Rex Inside the Bizarre World of Nature s Most Dangerous Creatures Free Press ISBN 978 0 7432 0011 0 Leone Stacy E 2008 Predator Induced Plasticity in Barnacle Shell Morphology Master of Arts in Biology thesis Central Connecticut State University OCLC 713734094 Archived from the original on 2019 07 15 Retrieved 2019 07 15 page needed Zheden Vanessa Kovalev Alexander Gorb Stanislav N Klepal Waltraud 2015 02 06 Characterization of cement float buoyancy in the stalked barnacle Dosima fascicularis Crustacea Cirripedia Interface Focus 5 1 20140060 doi 10 1098 rsfs 2014 0060 ISSN 2042 8898 PMC 4275874 PMID 25657839 Stanley Steven M 8 April 2016 Predation defeats competition on the seafloor Paleobiology 34 1 1 21 doi 10 1666 07026 1 S2CID 83713101 Clint Twist 2005 Visual Factfinder Oceans Great Bardfield Essex Miles Kelly Publishing Harley C D G Pankey M S Wares J P Grosberg R K Wonham M J December 2006 Color Polymorphism and Genetic Structure in the Sea Star The Biological Bulletin 211 3 248 262 doi 10 2307 4134547 JSTOR 4134547 PMID 17179384 S2CID 18549566 Jan Holmes 2002 Seashore players most successful when they re in their zone WSU Beach Watchers Archived from the original on 2010 06 21 Retrieved March 6 2010 a b Richmond Marsha January 2007 Darwin s Study of the Cirripedia Darwin Online Retrieved 16 June 2012 Etienne Benson Charles Darwin SparkNotes Archived from the original on 29 September 2007 Retrieved August 30 2007 a b van Wyhe John 2007 05 22 Mind the gap did Darwin avoid publishing his theory for many years Notes and Records of the Royal Society 61 2 177 205 doi 10 1098 rsnr 2006 0171 ISSN 0035 9149 S2CID 202574857 Bromham Lindell 2020 10 01 Comparability in evolutionary biology The case of Darwin s barnacles Linguistic Typology 24 3 427 463 doi 10 1515 lingty 2020 2056 hdl 1885 274303 ISSN 1613 415X S2CID 222319487 Lewis Charlton T Short Charles 1879 cirrus A Latin Dictionary Perseus Digital Library Lewis Charlton T Short Charles 1879 lavo A Latin Dictionary Perseus Digital Library Concise Oxford English Dictionary 10th ed Oxford University Press 2002 p 260 ISBN 0 19 860572 2 Martin Joel W Davis George E 2001 An Updated Classification of the Recent Crustacea CiteSeerX 10 1 1 79 1863 page needed Chan Benny K K Dreyer Niklas Gale Andy S Glenner Henrik et al 2021 The evolutionary diversity of barnacles with an updated classification of fossil and living forms Zoological Journal of the Linnean Society 193 3 789 846 doi 10 1093 zoolinnean zlaa160 a b c Chan Benny K K Dreyer Niklas Gale Andy S Glenner Henrik Ewers Saucedo Christine Perez Losada Marcos Kolbasov Gregory A Crandall Keith A Hoeg Jens T 2021 02 25 The evolutionary diversity of barnacles with an updated classification of fossil and living forms Zoological Journal of the Linnean Society 193 zlaa160 789 846 doi 10 1093 zoolinnean zlaa160 ISSN 0024 4082 B A Foster amp J S Buckeridge 1987 Barnacle palaeontology pp 41 63 In A J Southward ed 1987 Newcastle University Biofouling Group Newcastle University Archived from the original on June 5 2009 Retrieved January 15 2010 Pearson Ryan M van de Merwe Jason P Gagan Michael K Connolly Rod M 2020 Unique Post telemetry Recapture Enables Development of Multi Element Isoscapes From Barnacle Shell for Retracing Host Movement Frontiers in Marine Science 7 doi 10 3389 fmars 2020 00596 hdl 10072 395516 ISSN 2296 7745 Pearson Ryan M van de Merwe Jason P Gagan Michael K Limpus Colin J Connolly Rod M 25 April 2019 Distinguishing between sea turtle foraging areas using stable isotopes from commensal barnacle shells Scientific Reports 9 1 6565 Bibcode 2019NatSR 9 6565P doi 10 1038 s41598 019 42983 4 PMC 6483986 PMID 31024029 Can Barnacles unlock the secrets of MH370 and Turtle migration Griffith Sciences Impact 3 August 2015 Archived from the original on 15 July 2019 Retrieved 15 July 2019 Pandey Swati 3 August 2015 Barnacles on debris could provide clues to missing MH370 experts Reuters Pearson Ryan M van de Merwe Jason P Connolly Rod M 2020 Global oxygen isoscapes for barnacle shells Application for tracing movement in oceans Science of the Total Environment 705 135782 Bibcode 2020ScTEn 705m5782P doi 10 1016 j scitotenv 2019 135782 ISSN 0048 9697 PMID 31787294 S2CID 208536416 Molares Jose Freire Juan December 2003 Development and perspectives for community based management of the goose barnacle Pollicipes pollicipes fisheries in Galicia NW Spain PDF Fisheries Research 65 1 3 485 492 doi 10 1016 j fishres 2003 09 034 hdl 2183 90 Hyunwoo Yuk et al 2021 Rapid and coagulation independent haemostatic sealing by a paste inspired by barnacle glue Nature Biomedical Engineering 5 10 1131 1142 doi 10 1038 s41551 021 00769 y PMC 9254891 PMID 34373600 Further reading edit Alan J Southward ed 1987 06 01 Barnacle Biology Crustacean Issues Vol 5 Leiden Netherlands CRC Press A A Balkema ISBN 978 90 6191 628 4 External links edit nbsp Wikimedia Commons has media related to Cirripedia nbsp Wikispecies has information related to Cirripedia Barnacles from the Marine Education Society of Australasia Barnacles in Spain Article on barnacles in Spain and their collection and gastronomy Darwin C R 1852 The Lepadidae A monograph of the sub class Cirripedia with figures of all the species Vol 1 London Ray Society Darwin C R 1854 The Balanidae or sessile cirripedes the Verrucidae etc A monograph of the sub class Cirripedia with figures of all the species Vol 2 London Ray Society Calman William Thomas 1911 Barnacle Encyclopaedia Britannica Vol 3 11th ed p 409 Stebbing Thomas Roscoe Rede 1911 Thyrostraca Encyclopaedia Britannica Vol 26 11th ed pp 905 906 Portals nbsp Crustaceans nbsp Arthropods nbsp Paleontology nbsp Paleozoic nbsp Mesozoic Retrieved from https en wikipedia org w index php title Barnacle amp oldid 1185732279, wikipedia, wiki, book, books, library,

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