123-479: The kraken ( / ˈ k r ɑː k ən / ) is a legendary sea monster of enormous size, per its etymology something akin to a cephalopod , said to appear in the sea between Norway and Iceland . It is believed that the legend of the Kraken may have originated from sightings of giant squid , which may grow to 12–15 m (40–50 feet) in length. The kraken, as a subject of sailors' superstitions and mythos ,
246-427: A "shell vestige" or "gladius". The Incirrina have either a pair of rod-shaped stylets or no vestige of an internal shell, and some squid also lack a gladius. The shelled coleoids do not form a clade or even a paraphyletic group. The Spirula shell begins as an organic structure, and is then very rapidly mineralized. Shells that are "lost" may be lost by resorption of the calcium carbonate component. Females of
369-490: A German source qualified Pontoppidan to be the first source on kraken available to be read in the German language. A description of the kraken had been anticipated by Hans Egede . Denys-Montfort (1801) published on two giants, the "colossal octopus" with the enduring image of it attacking a ship, and the "kraken octopod", deemed to be the largest organism in zoology. Denys-Montfort matched his "colossal" with Pliny's tale of
492-602: A Norwegian dictionary, the root meaning of krake is "malformed or overgrown, crooked tree". It originates from Old Norse kraki , which is etymologically related to Old Norse krókr , lit. ' hook ' , cognate with "crook". This is backed up by the Swedish dictionary SAOB , published by the Swedish Academy , which gives essentially the exact same description for the word in Swedish and confirming
615-399: A cloud of dark ink to confuse predators . This sac is a muscular bag which originated as an extension of the hindgut. It lies beneath the gut and opens into the anus, into which its contents – almost pure melanin – can be squirted; its proximity to the base of the funnel means the ink can be distributed by ejected water as the cephalopod uses its jet propulsion. The ejected cloud of melanin
738-435: A depth of 80–100 fathoms (140–180 metres (460–590 ft) deep), it sometimes happens that the plummet bottoms at 20–30 fathoms (35–50 metres (115–164 ft) deep). But in this water stand the most abundant shoals of cod and lings . Then you can assume that the kraken lurks down there; as it is he who forms the artificial elevation of the bottom and by his secretions attracts fish there. But if those fishing notices that
861-451: A diversity of backgrounds. Experiments done in Dwarf chameleons testing these hypotheses showed that chameleon taxa with greater capacity for color change had more visually conspicuous social signals but did not come from more visually diverse habitats, suggesting that color change ability likely evolved to facilitate social signaling, while camouflage is a useful byproduct. Because camouflage
984-407: A fantastical approach. It seems the religious and moral implications of animals were far more significant than matching a physical likeness in these renderings. Nona C. Flores explains, "By the tenth century, artists were increasingly bound by allegorical interpretation, and abandoned naturalistic depictions." Cephalopod A cephalopod / ˈ s ɛ f ə l ə p ɒ d / is any member of
1107-529: A flat fan shape with a mucus film between the individual tentacles, while another, Sepioteuthis sepioidea , has been observed putting the tentacles in a circular arrangement. Cephalopods have advanced vision, can detect gravity with statocysts , and have a variety of chemical sense organs. Octopuses use their arms to explore their environment and can use them for depth perception. Most cephalopods rely on vision to detect predators and prey and to communicate with one another. Consequently, cephalopod vision
1230-620: A giant sea-crab, starfish or a polypus (octopus). Still, the bishop is considered to have been instrumental in sparking interest for the kraken in the English-speaking world, as well as becoming regarded as the authority on sea-serpents and krakens. Although it has been stated that the kraken ( Norwegian : krake ) was "described for the first time by that name" in the writings of Erik Pontoppidan , bishop of Bergen , in his Det første Forsøg paa Norges naturlige Historie "The First Attempt at [a] Natural History of Norway" (1752–53),
1353-652: A gunshot-like popping noise, thought to function to frighten away potential predators. Cephalopods employ a similar method of propulsion despite their increasing size (as they grow) changing the dynamics of the water in which they find themselves. Thus their paralarvae do not extensively use their fins (which are less efficient at low Reynolds numbers ) and primarily use their jets to propel themselves upwards, whereas large adult cephalopods tend to swim less efficiently and with more reliance on their fins. Early cephalopods are thought to have produced jets by drawing their body into their shells, as Nautilus does today. Nautilus
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#17327756547781476-453: A jet as a propulsion mechanism. Squids do not have the longitudinal muscles that octopus do. Instead, they have a tunic. This tunic is made of layers of collagen and it surrounds the top and the bottom of the mantle. Because they are made of collagen and not muscle, the tunics are rigid bodies that are much stronger than the muscle counterparts. This provides the squids some advantages for jet propulsion swimming. The stiffness means that there
1599-406: A length of 8 metres. They may terminate in a broadened, sucker-coated club. The shorter four pairs are termed arms , and are involved in holding and manipulating the captured organism. They too have suckers, on the side closest to the mouth; these help to hold onto the prey. Octopods only have four pairs of sucker-coated arms, as the name suggests, though developmental abnormalities can modify
1722-518: A massive "fish" which was many-horned or many-armed. The author also distinguished this from a sea-serpent . The kraken was described as a many-headed and clawed creature by Egede (1741)[1729], who stated it was equivalent to the Icelanders' hafgufa , but the latter is commonly treated as a fabulous whale. Erik Pontoppidan (1753), who popularized the kraken to the world, noted that it was multiple-armed according to lore, and conjectured it to be
1845-474: A muscle, which is why they can change their skin hue as rapidly as they do. Coloration is typically stronger in near-shore species than those living in the open ocean, whose functions tend to be restricted to disruptive camouflage . These chromatophores are found throughout the body of the octopus, however, they are controlled by the same part of the brain that controls elongation during jet propulsion to reduce drag. As such, jetting octopuses can turn pale because
1968-412: A name-theme referencing drags. Besides kraken , the monster went under a variety of names early on, the most common after kraken being horven ("the horv"). Icelandic philologist Finnur Jónsson explained this name in 1920 as an alternative form of harv ( lit. ' harrow ' ) and conjectured that this name was suggested by the inkfish's action of seeming to plow the sea. Some of
2091-512: A novel mechanism for spectral discrimination in cephalopods was described. This relies on the exploitation of chromatic aberration (wavelength-dependence of focal length). Numerical modeling shows that chromatic aberration can yield useful chromatic information through the dependence of image acuity on accommodation. The unusual off-axis slit and annular pupil shapes in cephalopods enhance this ability by acting as prisms which are scattering white light in all directions. In 2015, molecular evidence
2214-471: A rare form of physiological color change which utilizes neural control of muscles to change the morphology of their chromatophores. This neural control of chromatophores has evolved convergently in both cephalopods and teleosts fishes. With the exception of the Nautilidae and the species of octopus belonging to the suborder Cirrina , all known cephalopods have an ink sac, which can be used to expel
2337-588: A sea crab ( German : Seekrabbe ), which a later biologist has suggested to be one of the Hyas spp. It was also described as resembling Gessner's Cancer heracleoticus crab alleged to appear off the Finnish coast. von Bergen 's " bellua marina omnium vastissima " (meaning 'vastest-of-all sea-beast'), namely the trolwal ('ogre whale', 'troll whale') of Northern Europe, and the Teufelwal ('devil whale') of
2460-429: A shell-less subclass of cephalopods (squid, cuttlefish, and octopuses), have complex pigment containing cells called chromatophores which are capable of producing rapidly changing color patterns. These cells store pigment within an elastic sac which produces the color seen from these cells. Coleoids can change the shape of this sac, called the cytoelastic sacculus, which then causes changes in the translucency and opacity of
2583-491: A ship down, Montfort made a more daring hypothesis. He attempted to blame colossal octopuses for the loss of ten warships under British control in 1782, including six captured French men-of-war. The disaster began with the distress signal fired by the captured ship of the line Ville de Paris which was then swallowed up by parting waves, and the other ships coming to aid shared the same fate. He proposed, by process of elimination, that such an event could only be accounted for as
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#17327756547782706-453: A ship, and included the engraving in his book. However, an English author recapitulating Montfort's account of it attaches an illustration of it, which was captioned: "The Kraken supposed a sepia or cuttlefish", while attributing Montfort. Hamilton's book was not alone in recontextualizing Montfort's ship-assaulting colossal octopus as a kraken; for instance, the piece on the "kraken" by American zoologist Packard . The Frenchman Montfort used
2829-620: A startling array of fashions. As well as providing camouflage with their background, some cephalopods bioluminesce, shining light downwards to disguise their shadows from any predators that may lurk below. The bioluminescence is produced by bacterial symbionts; the host cephalopod is able to detect the light produced by these organisms. Bioluminescence may also be used to entice prey, and some species use colorful displays to impress mates, startle predators, or even communicate with one another. Cephalopods can change their colors and patterns in milliseconds, whether for signalling (both within
2952-540: A stone sinker, known as krake , but also krabbe in Norwegian or krabba in Swedish ( lit. ' crab ' ). Old Norse kraki mostly corresponds to these uses in modern Icelandic , meaning, among other things, "twig" and "drag", but also "pole/stake used in pole blockages [ sv ] " and " boat hook ". Swedish SAOB gives the translations of Icelandic kraki as "thin rod with hook on it", "wooden drag with stone sinker" and "dry spruce trunk with
3075-470: A whole fleet". Legendary creature A legendary creature (also called a mythical creature or mythological creature ) is a type of fantasy entity, typically a hybrid , that has not been proven and that is described in folklore (including myths and legends ), but may be featured in historical accounts before modernity . In the classical era , monstrous creatures such as the Cyclops and
3198-531: A young and careless one", which washed ashore and died in 1680 near Alstahaug Church on the island of Alsta , Norway. He observed that it had long "arms", and guessed that it must have been crawling like a snail/slug with the use of these "arms", but got lodged in the landscape during the process. 20th century malacologist Paul Bartsch conjectured this to have been a giant squid , as did literary scholar Finnur Jónsson. However, what Pontoppidan actually stated regarding what creatures he regarded as candidates for
3321-539: Is a branch of malacology known as teuthology . Cephalopods became dominant during the Ordovician period, represented by primitive nautiloids . The class now contains two, only distantly related, extant subclasses: Coleoidea , which includes octopuses , squid , and cuttlefish ; and Nautiloidea , represented by Nautilus and Allonautilus . In the Coleoidea, the molluscan shell has been internalized or
3444-698: Is absent, whereas in the Nautiloidea, the external shell remains. About 800 living species of cephalopods have been identified. Two important extinct taxa are the Ammonoidea (ammonites) and Belemnoidea (belemnites). Extant cephalopods range in size from the 10 mm (0.3 in) Idiosepius thailandicus to the 700 kilograms (1,500 lb) heavy Colossal squid , the largest extant invertebrate . There are over 800 extant species of cephalopod, although new species continue to be described. An estimated 11,000 extinct taxa have been described, although
3567-516: Is acute: training experiments have shown that the common octopus can distinguish the brightness, size, shape, and horizontal or vertical orientation of objects. The morphological construction gives cephalopod eyes the same performance as shark eyes; however, their construction differs, as cephalopods lack a cornea and have an everted retina. Cephalopods' eyes are also sensitive to the plane of polarization of light. Unlike many other cephalopods, nautiluses do not have good vision; their eye structure
3690-463: Is also capable of creating a jet by undulations of its funnel; this slower flow of water is more suited to the extraction of oxygen from the water. When motionless, Nautilus can only extract 20% of oxygen from the water. The jet velocity in Nautilus is much slower than in coleoids , but less musculature and energy is involved in its production. Jet thrust in cephalopods is controlled primarily by
3813-421: Is also known as Echte Kraken ("true krakens") in German. In Icelandic , octopoda is instead named kolkrabbar ("coal crabs") after the crab nickname, the common octopus simply named kolkrabbi . The Swedish diminutive form kräkel , a word for a branchy/spiny piece of wood, have given name to a variety of sea dwelling plants in Swedish, most notably furcellaria lumbricalis , a species of red algae . There
Kraken - Misplaced Pages Continue
3936-411: Is also the morphological derivation kräkla (dialectal Norwegian : krekle ), meaning crooked piece of wood, which has given name to primitive forms of whisks and beaters (cooking), made from the tops of trees by keeping a row of twigs as the beating element, resembling the appearance of a cephalopod , but also crosiers and shepherd's crooks . Shetlandic krekin for "whale", a taboo word ,
4059-570: Is aragonite. As for other mollusc shells or coral skeletons, the smallest visible units are irregular rounded granules. Cephalopods, as the name implies, have muscular appendages extending from their heads and surrounding their mouths. These are used in feeding, mobility, and even reproduction. In coleoids they number eight or ten. Decapods such as cuttlefish and squid have five pairs. The longer two, termed tentacles , are actively involved in capturing prey; they can lengthen rapidly (in as little as 15 milliseconds ). In giant squid they may reach
4182-427: Is highly developed, but lacks a solid lens . They have a simple " pinhole " eye through which water can pass. Instead of vision, the animal is thought to use olfaction as the primary sense for foraging , as well as locating or identifying potential mates. All octopuses and most cephalopods are considered to be color blind . Coleoid cephalopods (octopus, squid, cuttlefish) have a single photoreceptor type and lack
4305-410: Is listed as etymologically related. In Norwegian sailor folklore, kraken ("the krake " or "the crookie"), also known as horven (among others), is a legendary sea monster said to appear in the sea between Norway and Iceland . It is said that when fishermen row out a few miles ( Scandinavian miles ) from the coast on a hot summer's day in a calm, and according to normal calculations should find
4428-418: Is more efficient, but in environments with little oxygen and in low temperatures, hemocyanin has the upper hand. The hemocyanin molecule is much larger than the hemoglobin molecule, allowing it to bond with 96 O 2 or CO 2 molecules, instead of the hemoglobin's just four. But unlike hemoglobin, which are attached in millions on the surface of a single red blood cell, hemocyanin molecules float freely in
4551-403: Is needed, compensating for their small size. However, organisms which spend most of their time moving slowly along the bottom do not naturally pass much water through their cavity for locomotion; thus they have larger gills, along with complex systems to ensure that water is constantly washing through their gills, even when the organism is stationary. The water flow is controlled by contractions of
4674-439: Is no necessary muscle flexing to keep the mantle the same size. In addition, tunics take up only 1% of the squid mantle's wall thickness, whereas the longitudinal muscle fibers take up to 20% of the mantle wall thickness in octopuses. Also because of the rigidity of the tunic, the radial muscles in squid can contract more forcefully. The mantle is not the only place where squids have collagen. Collagen fibers are located throughout
4797-457: Is referred to as a pseudomorph ). This strategy often results in the predator attacking the pseudomorph, rather than its rapidly departing prey. For more information, see Inking behaviors . The ink sac of cephalopods has led to a common name of "inkfish", formerly the pen-and-ink fish. Cephalopods are the only molluscs with a closed circulatory system. Coleoids have two gill hearts (also known as branchial hearts ) that move blood through
4920-709: Is suggesting this is an ancient example of kraken , as a modern commentator analyzes. Pontoppidan then declared the kraken to be a type of polypus (=octopus) or "starfish", particularly the kind Gessner called Stella Arborescens , later identifiable as one of the northerly ophiurids or possibly more specifically as one of the Gorgonocephalids or even the genus Gorgonocephalus (though no longer regarded as family/genus under order Ophiurida , but under Phrynophiurida in current taxonomy). This ancient arbor (admixed rota and thus made eight-armed) seems like an octopus at first blush but with additional data,
5043-413: Is supplemented with fin motion; in the squid, the fins flap each time that a jet is released, amplifying the thrust; they are then extended between jets (presumably to avoid sinking). Oxygenated water is taken into the mantle cavity to the gills and through muscular contraction of this cavity, the spent water is expelled through the hyponome , created by a fold in the mantle. The size difference between
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5166-553: Is the first evidence that cephalopod dermal tissues may possess the required combination of molecules to respond to light. Some squids have been shown to detect sound using their statocysts , but, in general, cephalopods are deaf. Most cephalopods possess an assemblage of skin components that interact with light. These may include iridophores, leucophores , chromatophores and (in some species) photophores . Chromatophores are colored pigment cells that expand and contract in accordance to produce color and pattern which they can use in
5289-423: Is the most complex of the invertebrates and their brain-to-body-mass ratio falls between that of endothermic and ectothermic vertebrates. Captive cephalopods have also been known to climb out of their aquaria, maneuver a distance of the lab floor, enter another aquarium to feed on captive crabs, and return to their own aquarium. The brain is protected in a cartilaginous cranium. The giant nerve fibers of
5412-426: Is unknown, but chromatophores are under the control of neural pathways, allowing the cephalopod to coordinate elaborate displays. Together, chromatophores and iridophores are able to produce a large range of colors and pattern displays. Cephalopods utilize chromatophores' color changing ability in order to camouflage themselves. Chromatophores allow Coleoids to blend into many different environments, from coral reefs to
5535-400: Is used for multiple adaptive purposes in cephalopods, color change could have evolved for one use and the other developed later, or it evolved to regulate trade offs within both. Color change is widespread in ectotherms including anoles, frogs, mollusks, many fish, insects, and spiders. The mechanism behind this color change can be either morphological or physiological. Morphological change is
5658-417: Is usually mixed, upon expulsion, with mucus , produced elsewhere in the mantle, and therefore forms a thick cloud, resulting in visual (and possibly chemosensory) impairment of the predator, like a smokescreen . However, a more sophisticated behavior has been observed, in which the cephalopod releases a cloud, with a greater mucus content, that approximately resembles the cephalopod that released it (this decoy
5781-517: The pieuvre octopus of Guernsey lore, which he identified with the kraken of legend. This led to Jules Verne 's depiction of the kraken, although Verne did not distinguish between squid and octopus. Linnaeus may have indirectly written about the kraken. Linnaeus wrote about the Microcosmus genus (an animal with various other organisms or growths attached to it, comprising a colony). Subsequent authors have referred to Linnaeus's writing, and
5904-538: The Holy Spirit , and the classical griffin represented a guardian of the dead. Medieval bestiaries included animals regardless of biological reality; the basilisk represented the devil , while the manticore symbolised temptation. One function of mythical animals in the Middle Ages was allegory . Unicorns, for example, were described as extraordinarily swift and uncatchable by traditional methods. It
6027-559: The Hydra to be killed by Heracles , while Aeneas battles with the harpies . These monsters thus have the basic function of emphasizing the greatness of the heroes involved. Some classical era creatures, such as the (horse/human) centaur , chimaera , Triton and the flying horse Pegasus , are found also in Indian art . Similarly, sphinxes appear as winged lions in Indian art and
6150-643: The King's Mirror in 1917 opted to translate hafgufa as kraken . The hafgufa (described as the largest of the sea monsters, inhabiting the Greenland Sea ) from the King's Mirror continues to be identified with the kraken in some scholarly writings, and if this equivalence were allowed, the kraken-hafgufa's range would extend, at least legendarily, to waters approaching Helluland ( Baffin Island , Canada), as described in Örvar-Odds saga . The description of
6273-489: The Minotaur appear in heroic tales for the protagonist to destroy. Other creatures, such as the unicorn , were claimed in accounts of natural history by various scholars of antiquity. Some legendary creatures originated in traditional mythology and were believed to be real creatures--for example, dragons , griffins and unicorns. Others are based on real encounters or garbled accounts of travellers' tales, such as
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#17327756547786396-458: The Piasa Bird of North America. In medieval art , animals, both real and mythical, played important roles. These included decorative forms as in medieval jewellery, sometimes with their limbs intricately interlaced. Animal forms were used to add humor or majesty to objects. In Christian art , animals carried symbolic meanings, where for example the lamb symbolized Christ, a dove indicated
6519-557: The Vegetable Lamb of Tartary , a sheeplike animal which supposedly grew tethered to the earth. A variety of mythical animals appear in the art and stories of the classical era . For example, in the Odyssey , monstrous creatures include the Cyclops , Scylla and Charybdis for the hero Odysseus to confront. Other tales include Medusa to be defeated by Perseus , the (human/bull) Minotaur to be destroyed by Theseus , and
6642-515: The hafgufa in the King's Mirror suggests a garbled eyewitness account of what was actually a whale, at least according to the Grönlands historiske Mindesmaerker . Halldór Hermannsson [ sv ] also reads the work as describing the hafgufa as a type of whale. Finnur Jónsson (1920) having arrived at the opinion that the kraken probably represented an inkfish (squid/octopus), as discussed earlier, expressed his skepticism towards
6765-529: The molluscan class Cephalopoda / s ɛ f ə ˈ l ɒ p ə d ə / ( Greek plural κεφαλόποδες , kephalópodes ; "head-feet") such as a squid , octopus , cuttlefish , or nautilus . These exclusively marine animals are characterized by bilateral body symmetry , a prominent head, and a set of arms or tentacles ( muscular hydrostats ) modified from the primitive molluscan foot. Fishers sometimes call cephalopods " inkfish ", referring to their common ability to squirt ink . The study of cephalopods
6888-583: The sparkling enope squid ( Watasenia scintillans ). It achieves color vision with three photoreceptors , which are based on the same opsin , but use distinct retinal molecules as chromophores: A1 (retinal), A3 (3-dehydroretinal), and A4 (4-hydroxyretinal). The A1-photoreceptor is most sensitive to green-blue (484 nm), the A2-photoreceptor to blue-green (500 nm), and the A4-photoreceptor to blue (470 nm) light. In 2015,
7011-603: The French malacologist Pierre Denys de Montfort recognized the existence of two "species" of giant octopuses in Histoire Naturelle Générale et Particulière des Mollusques , an encyclopedic description of mollusks. The "colossal giant" was supposedly the same as Pliny 's "monstrous polypus", which was a man-killer which ripped apart ( Latin : distrahit ) shipwrecked people and divers. Montfort accompanied his publication with an engraving representing
7134-526: The Germans follow in the list. It is in his chapter on the "colossal octopus" that Montfort provides the contemporary eyewitness example of a group of sailors who encounter the giant off the coast of Angola , who afterwards deposited a pictorial commemoration of the event as a votive offering at St. Thomas's chapel in Saint-Malo , France. Based on that picture, Montfort drew a "colossal octopus" attacking
7257-556: The ability to determine color by comparing detected photon intensity across multiple spectral channels. When camouflaging themselves, they use their chromatophores to change brightness and pattern according to the background they see, but their ability to match the specific color of a background may come from cells such as iridophores and leucophores that reflect light from the environment. They also produce visual pigments throughout their body and may sense light levels directly from their body. Evidence of color vision has been found in
7380-452: The acidity of the organic shell matrix (see Mollusc shell ); shell-forming cephalopods have an acidic matrix, whereas the gladius of squid has a basic matrix. The basic arrangement of the cephalopod outer wall is: an outer (spherulitic) prismatic layer, a laminar (nacreous) layer and an inner prismatic layer. The thickness of every layer depends on the taxa. In modern cephalopods, the Ca carbonate
7503-575: The aforementioned identification of krake as being the same as the hafgufa of the Icelanders, though he seemed to have obtained the information indirectly from the medieval Norwegian treatise, the Speculum Regale (or King's Mirror , c. 1250 ). Later, David Crantz [ de ] in Historie von Grönland ( History of Greenland , 1765) also reported kraken and the hafgufa to be synonymous. An English translator of
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#17327756547787626-434: The air for distances of up to 50 metres (160 ft). While cephalopods are not particularly aerodynamic, they achieve these impressive ranges by jet-propulsion; water continues to be expelled from the funnel while the organism is in the air. The animals spread their fins and tentacles to form wings and actively control lift force with body posture. One species, Todarodes pacificus , has been observed spreading tentacles in
7749-454: The appearance of their surroundings is notable given that cephalopods' vision is monochromatic. Cephalopods also use their fine control of body coloration and patterning to perform complex signaling displays for both conspecific and intraspecific communication. Coloration is used in concert with locomotion and texture to send signals to other organisms. Intraspecifically this can serve as a warning display to potential predators. For example, when
7872-403: The bloodstream. Cephalopods exchange gases with the seawater by forcing water through their gills, which are attached to the roof of the organism. Water enters the mantle cavity on the outside of the gills, and the entrance of the mantle cavity closes. When the mantle contracts, water is forced through the gills, which lie between the mantle cavity and the funnel. The water's expulsion through
7995-517: The body cavity; others, like some fish, accumulate oils in the liver; and some octopuses have a gelatinous body with lighter chloride ions replacing sulfate in the body chemistry. Squids are the primary sufferers of negative buoyancy in cephalopods. The negative buoyancy means that some squids, especially those whose habitat depths are rather shallow, have to actively regulate their vertical positions. This means that they must expend energy, often through jetting or undulations, in order to maintain
8118-455: The bottom, which can even appear as high as ship's masts. After a while, the kraken gives in to sinking again, and you then have to be careful not to run into the suction vortex that is formed. The first description of the krake as " sciu-crak " was given by Italian writer Negri in Viaggio settentrionale (Padua, 1700), a travelogue about Scandinavia. The book describes the sciu-crak as
8241-582: The brain is unable to achieve both controlling elongation and controlling the chromatophores. Most octopuses mimic select structures in their field of view rather than becoming a composite color of their full background. Evidence of original coloration has been detected in cephalopod fossils dating as far back as the Silurian ; these orthoconic individuals bore concentric stripes, which are thought to have served as camouflage. Devonian cephalopods bear more complex color patterns, of unknown function. Coleoids,
8364-401: The capillaries of the gills . A single systemic heart then pumps the oxygenated blood through the rest of the body. Like most molluscs, cephalopods use hemocyanin , a copper-containing protein, rather than hemoglobin , to transport oxygen. As a result, their blood is colorless when deoxygenated and turns blue when bonded to oxygen. In oxygen-rich environments and in acidic water, hemoglobin
8487-473: The catch was so plentiful (hence the saying "You must have fished on Kraken"). However, there was also the danger to seamen of being engulfed by the whirlpool when it submerged, and this whirlpool was compared to Norway's famed Moskstraumen often known as "the Maelstrom". Pontoppidan also described the destructive potential of the giant beast: "it is said that if [the creature's arms] were to lay hold of
8610-436: The cavity by entering not only through the orifices, but also through the funnel. Squid can expel up to 94% of the fluid within their cavity in a single jet thrust. To accommodate the rapid changes in water intake and expulsion, the orifices are highly flexible and can change their size by a factor of twenty; the funnel radius, conversely, changes only by a factor of around 1.5. Some octopus species are also able to walk along
8733-561: The cell. By rapidly changing multiple chromatophores of different colors, cephalopods are able to change the color of their skin at astonishing speeds, an adaptation that is especially notable in an organism that sees in black and white. Chromatophores are known to only contain three pigments, red, yellow, and brown, which cannot create the full color spectrum. However, cephalopods also have cells called iridophores, thin, layered protein cells that reflect light in ways that can produce colors chromatophores cannot. The mechanism of iridophore control
8856-399: The cephalopod mantle have been widely used for many years as experimental material in neurophysiology ; their large diameter (due to lack of myelination ) makes them relatively easy to study compared with other animals. Many cephalopods are social creatures; when isolated from their own kind, some species have been observed shoaling with fish. Some cephalopods are able to fly through
8979-493: The crooked, stripped branches still attached". Kraken is assumed to have been named figuratively after the meaning “crooked tree” or its derivate meaning “drag”, as trunks with crooked branches or outgrowths, and especially drags, wooden or not, readily conjure up the image of a cephalopod or similar. This idea seems to first have been notably remarked by Icelandic philologist Finnur Jónsson in 1920. A synonym for kraken has also been krabbe (see below), which further indicates
9102-491: The depth of the ocean, from the abyssal plains to the sea surface, and have also been found in the hadal zone . Their diversity is greatest near the equator (~40 species retrieved in nets at 11°N by a diversity study) and decreases towards the poles (~5 species captured at 60°N). Cephalopods are widely regarded as the most intelligent of the invertebrates and have well developed senses and large brains (larger than those of gastropods ). The nervous system of cephalopods
9225-407: The depths. Egede conjectured that the krake was equatable to the monster that the Icelanders call hafgufa , but as he had not obtained anything related to him through an informant, he had difficulty describing the latter. According to the lore of Norwegian fishermen, they could mount upon the fish-attracting kraken as if it were a sand-bank ( Fiske-Grund 'fishing shoal '), but if they ever had
9348-469: The expansion of the mantle at the end of the jet. In some tests, the collagen has been shown to be able to begin raising mantle pressure up to 50ms before muscle activity is initiated. These anatomical differences between squid and octopuses can help explain why squid can be found swimming comparably to fish while octopuses usually rely on other forms of locomotion on the sea floor such as bipedal walking, crawling, and non-jetting swimming. Nautiluses are
9471-493: The fables of his native region, the Nordlandene len [ no ] of Norway, then under Danish rule. According to his Norwegian informants, the kraken's body measured many miles in length, and when it surfaced it seemed to cover the whole sea, further described as "having many heads and a number of claws". With its claws it captured its prey, which included ships, men, fish, and animals, carrying its victims back into
9594-413: The form of jetting. The composition of these mantles differs between the two families, however. In octopuses, the mantle is made up of three muscle types: longitudinal, radial, and circular. The longitudinal muscles run parallel to the length of the octopus and they are used in order to keep the mantle the same length throughout the jetting process. Given that they are muscles, it can be noted that this means
9717-456: The funnel can be used to power jet propulsion. If respiration is used concurrently with jet propulsion, large losses in speed or oxygen generation can be expected. The gills, which are much more efficient than those of other mollusks, are attached to the ventral surface of the mantle cavity. There is a trade-off with gill size regarding lifestyle. To achieve fast speeds, gills need to be small – water will be passed through them quickly when energy
9840-448: The giant polypus that attacked ships-wrecked people, while making correspondence between his kraken and Pliny's monster called the arbor marina . Finnur Jónsson (1920) also favored identifying the kraken as an inkfish (squid/octopus) on etymological grounds. The krake (English: kraken) was described by Hans Egede in his Det gamle Grønlands nye perlustration (1729; Ger. t. 1730; tr. Description of Greenland , 1745), drawing from
9963-440: The giant octopus poised to destroy a three-masted ship. Whereas the "kraken octopus", was the most gigantic animal on the planet in the writer's estimation, dwarfing Pliny's "colossal octopus"/"monstrous polypus", and identified here as the aforementioned Pliny's monster, called the arbor marinus . Montfort also listed additional wondrous fauna as identifiable with the kraken. There was Paullini 's monstrum marinum glossed as
10086-561: The horn of a unicorn." This is because the translators of the King James erroneously translated the Hebrew word re'em as unicorn. Later versions translate this as wild ox. The unicorn's small size signifies the humility of Christ. Another common legendary creature that served allegorical functions within the Middle Ages was the dragon . Dragons were identified with serpents, though their attributes were greatly intensified. The dragon
10209-513: The kraken is quite complicated. Pontoppidan did tentatively identify the kraken to be a sort of giant crab, stating that the alias krabben best describes its characteristics. However, further down in his writing, compares the creature to some creature(s) from Pliny, Book IX, Ch. 4: the sea-monster called arbor , with tree-branch like multiple arms, complicated by the fact that Pontoppidan adds another of Pliny's creature called rota with eight arms, and conflates them into one organism. Pontoppidan
10332-411: The kraken is rising, it is necessary to row away for all the boat can take. After a few minutes, the beast can then be seen lifting the upper part of its body above the surface of the water, which for a quarter of a mile (ca 1.5 mi.) in circumference appears as a collection of skerries , covered with swaying, seaweed-like growths. Finally, a few shining tentacles rise up in the air, increasingly thicker at
10455-404: The largest man-of-war , they would pull it down to the bottom". Kraken purportedly exclusively fed for several months, then spent the following few months emptying its excrement, and the thickened clouded water attracted fish. Later Henry Lee commented that the supposed excreta may have been the discharge of ink by a cephalopod. Pontoppidan wrote of a possible specimen of the krake, "perhaps
10578-436: The lead krak as a diminutive form of krok , Norwegian and Swedish for 'hook/crook' ( krake thus roughly translate to "crookie"). With time, "krake" have come to mean any severed tree stem or trunk with crooked outgrowths, in turn giving name to objects and tools based on such, notably for the subject matter, primitive anchors and drags ( grapnel anchors ) made from severed spruce tops or branchy bush trunks outfitted with
10701-472: The maximum diameter of the funnel orifice (or, perhaps, the average diameter of the funnel) and the diameter of the mantle cavity. Changes in the size of the orifice are used most at intermediate velocities. The absolute velocity achieved is limited by the cephalopod's requirement to inhale water for expulsion; this intake limits the maximum velocity to eight body-lengths per second, a speed which most cephalopods can attain after two funnel-blows. Water refills
10824-492: The misfortune to capture the kraken, getting it entangled on their hooks, the only way to avoid destruction was to pronounce its name to make it go back to its depths. Egede also wrote that the krake fell under the general category of "sea spectre" ( Danish : søe-trold og [ søe ]- spøgelse ), adding that "the Draw" ( Danish : Drauen , definite form) was another being within that sea spectre classification. Egede also made
10947-404: The non threatening herbivorous parrotfish to approach unaware prey. The octopus Thaumoctopus mimicus is known to mimic a number of different venomous organisms it cohabitates with to deter predators. While background matching, a cephalopod changes its appearance to resemble its surroundings, hiding from its predators or concealing itself from prey. The ability to both mimic other organisms and match
11070-404: The obsolete scientific name Sepia octopodia but called it a poulpe , which means "octopus" to this day; meanwhile the English-speaking naturalists had developed the convention of calling the octopus "eight-armed cuttle-fish", as did Packard and Hamilton, even though modern-day speakers are probably unfamiliar with that name. Having accepted as fact that a colossal octopus was capable of dragging
11193-413: The octopus Callistoctopus macropus is threatened, it will turn a bright red brown color speckled with white dots as a high contrast display to startle predators. Conspecifically, color change is used for both mating displays and social communication. Cuttlefish have intricate mating displays from males to females. There is also male to male signaling that occurs during competition over mates, all of which are
11316-443: The octopus genus Argonauta secrete a specialized paper-thin egg case in which they reside, and this is popularly regarded as a "shell", although it is not attached to the body of the animal and has a separate evolutionary origin. The largest group of shelled cephalopods, the ammonites , are extinct, but their shells are very common as fossils . The deposition of carbonate, leading to a mineralized shell, appears to be related to
11439-444: The octopus must actively flex the longitudinal muscles during jetting in order to keep the mantle at a constant length. The radial muscles run perpendicular to the longitudinal muscles and are used to thicken and thin the wall of the mantle. Finally, the circular muscles are used as the main activators in jetting. They are muscle bands that surround the mantle and expand/contract the cavity. All three muscle types work in unison to produce
11562-497: The only extant cephalopods with a true external shell. However, all molluscan shells are formed from the ectoderm (outer layer of the embryo); in cuttlefish ( Sepia spp.), for example, an invagination of the ectoderm forms during the embryonic period, resulting in a shell ( cuttlebone ) that is internal in the adult. The same is true of the chitinous gladius of squid and octopuses. Cirrate octopods have arch-shaped cartilaginous fin supports , which are sometimes referred to as
11685-411: The ophiurid starfish now appears bishop's preferential choice. The ophiurid starfish seems further fortified when he notes that "starfish" called "Medusa's heads" ( caput medusæ ; pl. capita medusæ ) are considered to be "the young of the great sea-krake" by local lore. Pontoppidan ventured the 'young krakens' may rather be the eggs ( ova ) of the starfish. Pontopiddan was satisfied that "Medusa's heads"
11808-440: The other muscle fibers in the mantle. These collagen fibers act as elastics and are sometimes named "collagen springs". As the name implies, these fibers act as springs. When the radial and circular muscles in the mantle contract, they reach a point where the contraction is no longer efficient to the forward motion of the creature. In such cases, the excess contraction is stored in the collagen which then efficiently begins or aids in
11931-419: The persistently accepted notion that the kraken originated from the hafgufa . Erik Pontoppidan's Det første Forsøg paa Norges naturlige Historie (1752, actually volume 2, 1753) made several claims regarding kraken, including the notion that the creature was sometimes mistaken for a group of small islands with fish swimming in-between, Norwegian fishermen often took the risk of trying to fish over kraken, since
12054-442: The posterior and anterior ends of this organ control the speed of the jet the organism can produce. The velocity of the organism can be accurately predicted for a given mass and morphology of animal. Motion of the cephalopods is usually backward as water is forced out anteriorly through the hyponome, but direction can be controlled somewhat by pointing it in different directions. Some cephalopods accompany this expulsion of water with
12177-407: The product of chromatophore coloration displays. There are two hypotheses about the evolution of color change in cephalopods. One hypothesis is that the ability to change color may have evolved for social, sexual, and signaling functions. Another explanation is that it first evolved because of selective pressures encouraging predator avoidance and stealth hunting. For color change to have evolved as
12300-431: The radial and circular mantle cavity muscles. The gills of cephalopods are supported by a skeleton of robust fibrous proteins; the lack of mucopolysaccharides distinguishes this matrix from cartilage. The gills are also thought to be involved in excretion, with NH 4 being swapped with K from the seawater. While most cephalopods can move by jet propulsion, this is a very energy-consuming way to travel compared to
12423-441: The result of a change in the density of pigment containing cells and tends to change over longer periods of time. Physiological change, the kind observed in cephalopod lineages, is typically the result of the movement of pigment within the chromatophore, changing where different pigments are localized within the cell. This physiological change typically occurs on much shorter timescales compared to morphological change. Cephalopods have
12546-439: The result of natural selection different parameters would have to be met. For one, you would need some phenotypic diversity in body patterning among the population. The species would also need to cohabitate with predators which rely on vision for prey identification. These predators should have a high range of visual sensitivity, detecting not just motion or contrast but also colors. The habitats they occupy would also need to display
12669-424: The result of social selection the environment of cephalopods' ancestors would have to fit a number of criteria. One, there would need to be some kind of mating ritual that involved signaling. Two, they would have to experience demonstrably high levels of sexual selection. And three, the ancestor would need to communicate using sexual signals that are visible to a conspecific receiver. For color change to have evolved as
12792-549: The same class. Octopuses are generally not seen as active swimmers; they are often found scavenging the sea floor instead of swimming long distances through the water. Squids, on the other hand, can be found to travel vast distances, with some moving as much as 2000 km in 2.5 months at an average pace of 0.9 body lengths per second. There is a major reason for the difference in movement type and efficiency: anatomy. Both octopuses and squids have mantles (referenced above) which function towards respiration and locomotion in
12915-399: The same depth. As such, the cost of transport of many squids are quite high. That being said, squid and other cephalopod that dwell in deep waters tend to be more neutrally buoyant which removes the need to regulate depth and increases their locomotory efficiency. The Macrotritopus defilippi , or the sand-dwelling octopus, was seen mimicking both the coloration and the swimming movements of
13038-452: The sand-dwelling flounder Bothus lunatus to avoid predators. The octopuses were able to flatten their bodies and put their arms back to appear the same as the flounders as well as move with the same speed and movements. Females of two species, Ocythoe tuberculata and Haliphron atlanticus , have evolved a true swim bladder . Two of the categories of cephalopods, octopus and squid, are vastly different in their movements despite being of
13161-446: The sandy sea floor. The color change of chromatophores works in concert with papillae, epithelial tissue which grows and deforms through hydrostatic motion to change skin texture. Chromatophores are able to perform two types of camouflage, mimicry and color matching. Mimicry is when an organism changes its appearance to appear like a different organism. The squid Sepioteuthis sepioide has been documented changing its appearance to appear as
13284-489: The seabed. Squids and cuttlefish can move short distances in any direction by rippling of a flap of muscle around the mantle. While most cephalopods float (i.e. are neutrally buoyant or nearly so; in fact most cephalopods are about 2–3% denser than seawater ), they achieve this in different ways. Some, such as Nautilus , allow gas to diffuse into the gap between the mantle and the shell; others allow purer water to ooze from their kidneys, forcing out denser salt water from
13407-608: The soft-bodied nature of cephalopods means they are not easily fossilised. Cephalopods are found in all the oceans of Earth. None of them can tolerate fresh water , but the brief squid, Lolliguncula brevis , found in Chesapeake Bay , is a notable partial exception in that it tolerates brackish water . Cephalopods are thought to be unable to live in fresh water due to multiple biochemical constraints, and in their >400 million year existence have never ventured into fully freshwater habitats. Cephalopods occupy most of
13530-440: The species and for warning ) or active camouflage , as their chromatophores are expanded or contracted. Although color changes appear to rely primarily on vision input, there is evidence that skin cells, specifically chromatophores , can detect light and adjust to light conditions independently of the eyes. The octopus changes skin color and texture during quiet and active sleep cycles. Cephalopods can use chromatophores like
13653-536: The synonyms of krake given by Erik Pontoppidan were, in Danish : Since the 19th century, the word krake have, beyond the monster, given name to the cephalopod order Octopoda in Swedish ( krakar ) and German ( Kraken ), resulting in many species of octopuses partly named such, such as the common octopus ( Octopus vulgaris ), which is named jättekrake ("giant kraken") in Swedish and Gewöhnlicher Krake ("common kraken") in German. The family Octopodidae
13776-459: The tail propulsion used by fish. The efficiency of a propeller -driven waterjet (i.e. Froude efficiency ) is greater than a rocket . The relative efficiency of jet propulsion decreases further as animal size increases; paralarvae are far more efficient than juvenile and adult individuals. Since the Paleozoic era , as competition with fish produced an environment where efficient motion
13899-471: The whole genus of Kors-Trold ['cross troll'], ... some that are much larger, .. even the very largest ... of the ocean", and concluding that "this Krake must be of the Polypus kind". By "this Krake" here, he apparently meant in particular the giant polypus octopus of Carteia from Pliny, Book IX, Ch. 30 (though he only used the general nickname " ozaena " 'stinkard' for the octopus kind). In 1802,
14022-448: The work of many octopuses. But it has been pointed out the sinkings have simply been explained by the presence of a storm, and there appeared a surviving witness that stated they ran into a hurricane. Montfort's involving octopuses as complicit has been characterized as "reckless falsity". It has also been noted that Montfort once quipped to a friend, DeFrance : "If my entangled ship is accepted, I will make my 'colossal poulpe' overthrow
14145-421: The writings of Bartholin 's cetus called hafgufa , and Paullini 's monstrum marinum as "krakens". That said, the claim that Linnaeus used the word "kraken" in the margin of a later edition of Systema Naturae has not been confirmed. The English word "kraken" (in the sense of sea monster) derives from Norwegian kraken or krakjen , which are the definite forms of krake ("the krake"). According to
14268-440: Was always heat present in these locations. Physical detail was not the central focus of the artists depicting such animals, and medieval bestiaries were not conceived as biological categorizations. Creatures like the unicorn and griffin were not categorized in a separate "mythological" section in medieval bestiaries, as the symbolic implications were of primary importance. Animals we know to have existed were still presented with
14391-480: Was believed that the only way for one to catch this beast was to lead a virgin to its dwelling. Then, the unicorn was supposed to leap into her lap and go to sleep, at which point a hunter could finally capture it. In terms of symbolism, the unicorn was a metaphor for Christ. Unicorns represented the idea of innocence and purity. In the King James Bible , Psalm 92 :10 states, "My horn shalt thou exalt like
14514-463: Was crucial to survival, jet propulsion has taken a back role, with fins and tentacles used to maintain a steady velocity. Whilst jet propulsion is never the sole mode of locomotion, the stop-start motion provided by the jets continues to be useful for providing bursts of high speed – not least when capturing prey or avoiding predators . Indeed, it makes cephalopods the fastest marine invertebrates, and they can out-accelerate most fish. The jet
14637-459: Was first described in the modern era in a travelogue by Francesco Negri in 1700. This description was followed in 1734 by an account from Dano-Norwegian missionary and explorer Hans Egede , who described the kraken in detail and equated it with the hafgufa of medieval lore. However, the first description of the creature is usually credited to the Danish bishop Pontoppidan (1753). Pontoppidan
14760-401: Was published indicating that cephalopod chromatophores are photosensitive; reverse transcription polymerase chain reactions (RT-PCR) revealed transcripts encoding rhodopsin and retinochrome within the retinas and skin of the longfin inshore squid ( Doryteuthis pealeii ), and the common cuttlefish ( Sepia officinalis ) and broadclub cuttlefish ( Sepia latimanus ). The authors claim this
14883-417: Was supposed to have been larger than all other animals. It was believed that the dragon had no harmful poison but was able to slay anything it embraced without any need for venom. Biblical scriptures speak of the dragon in reference to the devil, and they were used to denote sin in general during the Middle Ages. Dragons were said to have dwelled in places like Ethiopia and India, based on the idea that there
15006-403: Was the first to describe the kraken as an octopus (polypus) of tremendous size, and wrote that it had a reputation for pulling down ships. The French malacologist Denys-Montfort , of the 19th century, is also known for his pioneering inquiries into the existence of gigantic octopuses ( Octupi ). The great man-killing octopus entered French fiction when novelist Victor Hugo (1866) introduced
15129-494: Was the same as the foregoing starfish ( Stella arborensis of old), but "Medusa's heads" were something found ashore aplenty across Norway according to von Bergen , who thought it absurd these could be young "Kraken" since that would mean the seas would be full of (the adults). The "Medusa's heads" appear to be a Gorgonocephalid, with Gorgonocephalus spp. being tentatively suggested. In the end though, Pontoppidan again appears ambivalent, stating "Polype, or Star-fish [belongs to]
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