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Encyclopedia > SHARK
Shark
Fossil range: Late Devonian - Recent
Oceanic whitetip shark, Carcharhinus longimanus accompanied by pilot fish.
Oceanic whitetip shark, Carcharhinus longimanus accompanied by pilot fish.
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Subphylum: Vertebrata
Class: Chondrichthyes
Subclass: Elasmobranchii
Superorder: Selachimorpha
Orders

Carcharhiniformes
Heterodontiformes
Hexanchiformes
Lamniformes
Orectolobiformes
Pristiophoriformes
Squaliformes
Squatiniformes
Symmoriida Look up Shark in Wiktionary, the free dictionary. ... For the Celtic language, see Southwestern Brythonic language; for the residents of the English county, see Devon. ... Image:Oceanic Whitetip Shark. ... Binomial name (Poey, 1861) Range of oceanic whitetip shark Synonyms Squalus maou, Lesson 1822-1825 Squalus longimanus, Poey 1861 Pterolamiops longimanus Carcharhinus obtusus, Garman 1881 Carcharhinus insularum, Snyder 1904 Pterolamiops magnipinnis, Smith 1958 Pterolamiops budkeri, Fourmanoir 1961 The oceanic whitetip shark, Carcharhinus longimanus, is a large pelagic shark of tropical... Binomial name (Linnaeus, 1758) The pilot fish (Naucrates ductor) is a carnivorous fish that is a horse mackerel and belongs to the Carangidae family of fishes. ... For other uses, see Scientific classification (disambiguation). ... For other uses, see Animal (disambiguation). ... Typical Classes See below Chordates (phylum Chordata) are a group of animals that includes the vertebrates, together with several closely related invertebrates. ... This article does not cite any references or sources. ... Subclasses and Orders See text. ... Superorders Batoidea (rays and skates) Selachimorpha (sharks) Elasmobranchii is the subclass of cartilaginous fish that includes skates, rays (batoidea) and sharks (selachii). ... Scientific classification or biological classification refers to how biologists group and categorize extinct and living species of organisms. ... Families See text. ... Family Heterodontidae (bullhead sharks) The Heterodontiformes are a small order of very basal (primitive) modern sharks (Neoselachii) known colloquially as the bullhead sharks. ... Families Chlamydoselachidae (frilled shark) Hexanchidae (cow sharks) Hexanchiformes is the order consisting of the most primitive types of sharks, and numbering just a handful of species. ... Families Odontaspididae (sand tigers) Mitsukurinidae (goblin shark) Pseudocarchariidae (crocodile shark) Megachasmidae (megamouth shark) Alopiidae (thresher sharks) Cetorhinidae (basking shark) Lamnidae (mackerel sharks) Great Lamniformes is an order of sharks commonly known as the mackerel sharks. ... Families Parascyllidae (collared carpet sharks) Brachaeluridae (blind sharks) Orectolobidae (wobbegongs) Hemiscylliidae (bamboo sharks) Ginglymostomatidae (nurse sharks) Stegostomatidae (zebra shark) Rhincodontidae (whale shark) The order Orectolobiformes, also collectively known as the carpet sharks or wobbegongs (in Australia) because most have carpet-like patterned markings, includes a number of familiar types of... Species Pliotrema warreni Pristiophorus cirratus Pristiophorus japonicus Pristiophorus nudipinnis Pristiophorus schroederi The sawsharks or saw sharks are an order (Pristiophoriformes) of sharks bearing long blade-like snouts edged with teeth, which they use to slash and disable their prey. ... Families Squalidae (dogfish sharks) Centrophoridae (gulper sharks) Dalatiidae (sleeper sharks) Echinorhinidae (bramble sharks) Squaliformes is an order of sharks that includes the smooth dogfish and spiny dogfish and others, about 80 species in four families. ... Species (16 species, see text) The angel sharks are an unusual group of sharks, with their flattened bodies and broad pectoral fins that give them a strong resemblance to skates and rays. ... This order contains three extinct famalies: Symmoriidae Falcatidae Stethacanthidae http://palaeo. ...

Sharks Portal

Sharks (superorder Selachimorpha) are fish with a full cartilaginous skeleton and a streamlined body. They respire with the use of five to seven gill slits. Sharks have a covering of dermal denticles to protect their skin from damage and parasites and to improve fluid dynamics; they also have replaceable teeth.[1] Shark teeth are prized by collectors for their beauty, and because they are the only surviving relics of ancient sharks that are now extinct. Sharks range in size from the small pygmy shark, Euprotomicrus bispinatus, a deep sea species of only 22 centimetres (9 in) in length, to the whale shark, Rhincodon typus, the largest fish, which grows to a length of approximately 12 metres (39 ft) and which, like baleen whales, feeds only on plankton, squid, and small fish through filter feeding. The bull shark, Carcharhinus leucas, is the best known of several species to swim in both salt and fresh water and in deltas.[2] Image File history File linksMetadata Greyreefsharksmall2. ... Scientific classification or biological classification refers to how biologists group and categorize extinct and living species of organisms. ... For other uses, see Fish (disambiguation). ... Cartilage is a type of dense connective tissue. ... Solid blue lines and broken grey lines represent the streamlines. ... For other uses, see Gill (disambiguation). ... Denticles or placoid scales are small outgrowths which cover the skin of many cartilaginous fish including sharks. ... A parasite is an organism that spends a significant portion of its life in or on the living tissue of a host organism and which causes harm to the host without immediately killing it. ... Fluid dynamics is the sub-discipline of fluid mechanics dealing with fluids (liquids and gases) in motion. ... A collection of fossilized shark teeth Shark teeth are relics of shark evolution and biology. ... Binomial name Euprotomicrus bispinatus (Quoy & Gaimard, 1824) The pygmy shark (Euprotomicrus bispinatus), the smallest of all the shark species, is a sleeper shark of the Dalatiinae subfamily, found in subtropical and warm temperate oceans worldwide, from the surface to depths of 1,800 metres. ... A centimetre (American spelling centimeter, symbol cm) is a unit of length that is equal to one hundredth of a metre, the current SI base unit of length. ... An inch (plural: inches; symbol or abbreviation: in or, sometimes, ″ - a double prime) is the name of a unit of length in a number of different systems, including English units, Imperial units, and United States customary units. ... Binomial name (Smith, 1828) Range of whale shark The whale shark, Rhincodon typus, is a slow filter feeding shark that is the largest living fish species. ... This article is about the unit of length. ... A foot (plural: feet or foot;[1] symbol or abbreviation: ft or, sometimes, ′ – a prime) is a unit of length, in a number of different systems, including English units, Imperial units, and United States customary units. ... Diversity Around 15 species; see list of cetaceans or below. ... For the SpongeBob SquarePants character, see Sheldon J. Plankton. ... For other uses, see Squid (disambiguation). ... For other uses, see Fish (disambiguation). ... Filter feeders (also known as suspension feeders) are animals that feed by straining suspended matter and food particles from water, typically by passing the water over a specialized structure, such as the baleen of baleen whales. ... Binomial name (Müller and Henle, 1839) Range of bull shark The bull shark, Carcharhinus leucas, also known as the bull whaler, Zambezi shark or informally Zambi in Africa and Nicaragua shark in Nicaragua, is common worldwide in warm, shallow waters along coasts and in rivers. ... Nile River delta, as seen from Earth orbit. ...

Contents

Physical characteristics

The physical characteristics of sharks are different from those of bony fish, but the large number of species and the diversity of shark habitats means that there are many variations on the typical shark body. ...

Skeleton

The skeleton of a shark is very different from that of bony fish and terrestrial vertebrates. Sharks and other cartilaginous fish (skates and rays) have skeletons made from rubbery cartilage, a tissue lighter and more flexible than bone.[1] Classes Actinopterygii Sarcopterygii Osteichthyes are a taxonomic superclass of fish, also called bony fish that includes the ray-finned fish (Actinopterygii) and lobe finned fish (Sarcopterygii). ... Groups See text. ... Subclasses and Orders See text. ... Cartilage is a type of dense connective tissue. ...


Like its relatives the rays and skates, the shark's jaw is not attached to the cranium. The jaw's surface, which like the vertebrae and gill arches is a skeletal element that needs extra support due to its heavier exposure to physical stress and need for extra strength, has a layer of unique and tiny hexagonal plates called "tesserae", crystal blocks of calcium salts arranged as a mosaic.[3] This gives these areas much of the same strength found in real and much heavier bony tissue.
The general rule is that there is only one layer of tesserae in sharks, but the jaws of large specimens, such as the bull shark, tiger shark, and the great white shark, have been found to be covered with both two and three layers, and even more, depending on the body size. The jaws of a large white shark even had five layers. Human jaw front view Human jaw left view Human jaw top view The jaw is either of the two opposable structures forming, or near the entrance to, the mouth. ... Cranium can mean: The brain and surrounding skull, a part of the body. ... Binomial name (Müller and Henle, 1839) Range of bull shark The bull shark, Carcharhinus leucas, also known as the bull whaler, Zambezi shark or informally Zambi in Africa and Nicaragua shark in Nicaragua, is common worldwide in warm, shallow waters along coasts and in rivers. ... For other uses, see Tiger shark (disambiguation). ... Binomial name (Linnaeus, 1758) Range (in blue) The great white shark, Carcharodon carcharias, also known as white pointer, white shark, or white death, is an exceptionally large lamniforme shark found in coastal surface waters in all major oceans. ...


In the rostrum (snout), the cartilage can be spongy and flexible to absorb the power of impacts.


The fin skeleton are elongated and supported with soft and unsegmented rays named ceratotrichia, filaments of elastic protein resembling the horny keratin in hair and feathers.


The inner parts of the males' pelvic fins have been modified to a pair of cigar- or sausage-shaped sex organs known as "claspers", used for internal fertilization.


Respiration

Like other fish, sharks extract oxygen from seawater as it passes over their gills. Shark gill slits are not covered like other fish, but are in a row behind its head. A modified slit called a spiracle is located just behind the eye; the spiracle assists the water intake during respiration and even plays a major role in bottom dwelling sharks, but is also reduced or missing in active pelagic sharks.[4] While moving, water passes through the mouth of the shark and over the gills — this process is known as "ram ventilation". While at rest, most sharks pump water over their gills to ensure a constant supply of oxygenated water. A small subset of shark species that spend their life constantly swimming, a behavior common in pelagic sharks, have lost the ability to pump water through their gills. These species are obligate ram ventilators and would presumably asphyxiate if unable to stay in motion. (Obligate ram ventilation is also true of some pelagic bony fish species.)[5] Image File history File links No higher resolution available. ... General Name, symbol, number oxygen, O, 8 Chemical series nonmetals, chalcogens Group, period, block 16, 2, p Appearance colorless (gas) pale blue (liquid) Standard atomic weight 15. ... Spiracles are small openings on the surface of animals that usually lead to respiratory systems. ... For other uses, see Eye (disambiguation). ... The pelagic zone is the part of the open sea or ocean comprising the water column, i. ... Asphyxia is a condition of severely deficient supply of oxygen to the body. ...


The respiration and circulation process begins when deoxygenated blood travels to the shark's two-chambered heart. Here the blood is pumped to the shark's gills via the ventral aorta artery where it branches off into afferent brachial arteries. Reoxygenation takes place in the gills and the reoxygenated blood flows into the efferent brachial arteries, which come together to form the dorsal aorta. The blood flows from the dorsal aorta throughout the body. The deoxygenated blood from the body then flows through the posterior cardinal veins and enters the posterior cardinal sinuses. From there blood enters the ventricle of the heart and the cycle repeats. In nervous systems, afferent signals or nerve fibers carry information toward the brain. ... Each primitive aorta receives anteriorly a vein—the vitelline vein—from the yolk-sac, and is prolonged backward on the lateral aspect of the notochord under the name of the dorsal aorta. ... During development of the veins, the first indication of a parietal system consists in the appearance of two short transverse veins, the ducts of Cuvier, which open, one on either side, into the sinus venosus. ...


Unlike bony fish, sharks do not have gas-filled swim bladders, but instead rely on a large liver filled with oil that contains squalene. The liver may constitute up to 30% of their body mass[6] for buoyancy. Its effectiveness is limited, so sharks employ dynamic lift to maintain depth and sink when they stop swimming. Some sharks, if inverted or stroked on the nose, enter a natural state of tonic immobility - researchers use this condition for handling sharks safely.[7] Sandtiger sharks are also known to gulp air from the surface and store it in their stomachs, using the stomach as a swim bladder. The gas bladder (also fish maw, less accurately swim bladder or air bladder) is an internal organ that contributes to the ability of a fish to control its buoyancy, and thus to stay at the current water depth, ascend, or descend without having to waste energy in swimming. ... Squalene is a natural organic compound originally obtained for commercial purposes primarily from shark liver oil, though there are botanic sources as well, including amaranth seed, rice bran, wheat germ, and olives. ... The prevailing type of fish locomotion is swimming in water. ... It has been suggested that Playing possum be merged into this article or section. ...


Osmoregulation

Main article: Osmoregulation

In contrast to bony fish, the blood and other tissue of sharks and Chondrichthyes in general is isotonic to their marine environments because of the high concentration of urea and trimethylamine oxide, allowing them to be in osmotic balance with the seawater. This adaptation prevents most sharks from surviving in fresh water, and they are therefore confined to a marine environment. A few exceptions to this rule exist, such as the bull shark, which has developed a way to change its kidney function to excrete large amounts of urea.[6] Osmoregulation is the active regulation of the osmotic pressure of bodily fluids to maintain the homeostasis of the bodys water content; that is it keeps the bodys fluids from becoming too dilute or too concentrated. ... 70. ... Marine is an umbrella term for things relating to the ocean, as with marine biology, marine geology, and as a term for a navy, etc. ... Binomial name (Müller and Henle, 1839) Range of bull shark The bull shark, Carcharhinus leucas, also known as the bull whaler, Zambezi shark or informally Zambi in Africa and Nicaragua shark in Nicaragua, is common worldwide in warm, shallow waters along coasts and in rivers. ...


Teeth

Main article: Shark teeth

The teeth of carnivorous sharks are not attached to the jaw, but embedded in the flesh, and in many species are constantly replaced throughout the shark's life; some sharks can lose 30,000 teeth in a lifetime. All sharks have multiple rows of teeth along the edges of their upper and lower jaws. New teeth grow continuously in a groove just inside the mouth and move forward from inside the mouth on a "conveyor belt" formed by the skin in which they are anchored. In some sharks rows of teeth are replaced every 8–10 days, while in other species they could last several months. The lower teeth are primarily used for holding prey, while the upper ones are used for cutting into it.[4] The teeth range from thin, needle-like teeth for gripping fish to large, flat teeth adapted for crushing shellfish.
A collection of fossilized shark teeth Shark teeth are relics of shark evolution and biology. ... Image File history File linksMetadata Download high-resolution version (2048x1536, 318 KB) Summary closeup of the teeth of the tiger shark, showing the serrated edges. ... Image File history File linksMetadata Download high-resolution version (2048x1536, 318 KB) Summary closeup of the teeth of the tiger shark, showing the serrated edges. ... For other uses, see Tiger shark (disambiguation). ... Human jaw front view Human jaw left view Human jaw top view The jaw is either of the two opposable structures forming, or near the entrance to, the mouth. ... Prey can refer to: Look up Prey in Wiktionary, the free dictionary A prey animal eaten by a predator in an act called predation. ...


Tails

The range of shark tail shapes

The tails (caudal fins) of sharks vary considerably between species and are adapted to the lifestyle of the shark. The tail provides thrust and so speed and acceleration are dependent on tail shape. Different tail shapes have evolved in sharks adapted for different environments. Sharks possess a heterocercal caudal fin in which the dorsal portion is usually noticeably larger than the ventral portion. This is due to the fact that the shark's vertebral column extends into that dorsal portion, allowing for a greater surface area for muscle attachment which would then be used for more efficient locomotion among the negatively buoyant cartilaginous fishes. This is in contrast to the bony fishes, class osteichthyes, which possess a homocercal caudal fin. Image File history File links Shark_Tail_shapes. ... A scorpion tail The tail is the section at the rear end of an animals body; in general, the term refers to a distinct, flexible appendage to the torso. ... In biology and physics, animal locomotion is the study of how animals move, and is part of biophysics. ... Classes Actinopterygii Sarcopterygii Osteichthyes are a taxonomic superclass of fish, also called bony fish that includes the ray-finned fish (Actinopterygii) and lobe finned fish (Sarcopterygii). ...


The tiger shark's tail has a large upper lobe which delivers the maximum amount of power for slow cruising or sudden bursts of speed. The tiger shark has a varied diet, and because of this it must be able to twist and turn in the water easily when hunting, whereas the porbeagle, which hunts schooling fish such as mackerel and herring has a large lower lobe to provide greater speed to help it keep pace with its fast-swimming prey. It is also believed that sharks use the upper lobe of their tails to counter the lift generated by their pectoral fins. [8] Binomial name Bonnaterre, 1788 Range of porbeagle (in blue) The porbeagle, Lamna nasus, is a large pelagic predatory shark of the family Lamnidae. ... Mackerel is a common name applied to a number of different species of fish, mostly, but not exclusively, from the family Scombridae. ... Species Clupea alba Clupea bentincki Clupea caspiopontica Clupea chrysotaenia Clupea elongata Clupea halec Clupea harengus Clupea inermis Clupea leachii Clupea lineolata Clupea minima Clupea mirabilis Clupea pallasii Clupea sardinacaroli Clupea sulcata Herrings are small oily fish of the genus Clupea found in the shallow, temperate waters of the North Atlantic...


Some tail adaptations have purposes other than providing thrust. The cookiecutter shark has a tail with broad lower and upper lobes of similar shape which are luminescent and may help to lure prey towards the shark. The thresher feeds on fish and squid, which it is believed to herd, then stun with its powerful and elongated upper lobe. Binomial name Isistius brasiliensis (Quoy & Gaimard, 1824) The Cookiecutter shark, Isistius brasiliensis (also known as the Cigar shark or Luminous shark) is a small rarely-seen dogfish shark. ... Species For species see text. ...


Dermal denticles

Main article: Dermal denticle

Unlike bony fish, sharks have a complex dermal corset made of flexible collagenous fibres and arranged as a helical network surrounding their body. This works as an outer skeleton, providing attachment for their swimming muscles and thus saving energy. In past days the sharks skin has been used as sandpaper. Also if you happen to rub a sharks skin it is possible for it to cut you. Denticles or placoid scales are small outgrowths which cover the skin of many cartilaginous fish including sharks. ...


Their dermal teeth give them hydrodynamic advantages as they reduce turbulence when swimming.[9]


Body temperature

A few of the larger species, such as the shortfin mako, Isurus oxyrinchus, and the great white, are mildly homeothermic[8] - able to maintain their body temperature above the surrounding water temperature. This is possible because of the presence of the rete mirabile, a counter current exchange mechanism that reduces the loss of body heat. Muscular contraction also generates a mild amount of body heat. However, this differs significantly from true homeothermy, as found in mammals and birds, in which heat is generated, maintained, and regulated by metabolic activity. Binomial name Rafinesque, 1810 Range of shortfin mako shark (in blue) The shortfin mako shark, Isurus oxyrinchus, (sharp nose) is a large shark of the Lamnidae family. ... Binomial name (Linnaeus, 1758) Range (in blue) For other uses, see Great White (disambiguation). ... A warm-blooded (homeothermic) animal is one that can keep its core body temperature at a nearly constant level regardless of the temperature of the surrounding environment (that is, to maintain thermal homeostasis) . This can involve not only the ability to generate heat, but also the ability to cool down... A rete mirabile (Latin for wonderful net) is a complex of arteries and veins lying very close to each other, found in a number of vertebrates, and serving different purposes. ...


Lifespan

Maximum shark ages vary by species. Most sharks live for 20 to 30 years, while the spiny dogfish lives a record lifespan of more than 100 years.[10] Whale sharks (Rhincodon typus) have been hypothesized to also live over 100 years.[11] Binomial name Squalus acanthias Linnaeus, 1758 The spiny dogfish or piked dogfish, Squalus acanthias, is one of the best known of the dogfish, members of the family Squalidae in the order Squaliformes. ... Binomial name Rhincodon typus Smith, 1828 The whale shark (Rhincodon typus) is a large, distinctively marked member of the subclass Elasmobranchii of the class Chondrichthyes. ...


Etymology

Until the 16th century,[12] sharks were known to mariners as "sea dogs".[13] According to the OED the name "shark" first came into use after Sir John Hawkins' sailors exhibited one in London in 1569 and used the word to refer to the large sharks of the Caribbean Sea, and later as a general term for all sharks. The name may have been derived from the Mayan word for fish, xoc, pronounced "shock" or "shawk". OED stands for Oxford English Dictionary Office of Enrollment & Discipline This page concerning a three-letter acronym or abbreviation is a disambiguation page — a navigational aid which lists other pages that might otherwise share the same title. ... For other persons named John Hawkins, see John Hawkins (disambiguation). ... Map of Central America and the Caribbean The Caribbean Sea (pronounced or ) is a tropical sea in the Western Hemisphere, part of the Atlantic Ocean, southeast of the Gulf of Mexico. ... Maya language may refer to: generally, any one of the various Mayan languages, a related group of languages spoken by the Maya peoples of Mesoamerica specifically, Yukatek (Yucatec) Maya language is frequently referred to simply as Maya language Maya language (Brazil), an unclassified language of Brazil that may be related...


Evolution

A collection of fossilised shark teeth
A collection of fossilised shark teeth

The fossil record of sharks extends back over 450 million years - before land vertebrates existed and before many plants had colonised the continents.[14] The first sharks looked very different from modern sharks.[15] The majority of the modern sharks can be traced back to around 100 million years ago.[16] Image File history File links Download high resolution version (847x981, 176 KB) Summary Sharks teeth collected and scanned by me User Debivort 2001. ... Image File history File links Download high resolution version (847x981, 176 KB) Summary Sharks teeth collected and scanned by me User Debivort 2001. ... A collection of fossilized shark teeth Shark teeth are relics of shark evolution and biology. ... It has been suggested that this article or section be merged into Fossil. ... Typical classes Petromyzontidae (lampreys) Placodermi - extinct Chondrichthyes (cartilaginous fish) Acanthodii - extinct Actinopterygii (ray-finned fish) Actinistia (coelacanths) Dipnoi (lungfish) Amphibia (amphibians) Reptilia (reptiles) Aves (birds) Mammalia (mammals) Vertebrata is a subphylum of chordates, specifically, those with backbones or spinal columns. ... u fuck in ua ...


Mostly only the fossilized teeth of sharks are found, although often in large numbers. In some cases pieces of the internal skeleton or even complete fossilized sharks have been discovered. Estimates suggest that over a span of a few years a shark may grow tens of thousands of teeth, which explains the abundance of fossils. As the teeth consist of calcium phosphate, an apatite, they are easily fossilized. Types of teeth Molars are used for grinding up foods Carnassials are used for slicing food. ... Calcium phosphate is the name given to a family of minerals containing calcium ions (Ca2+) together with orthophosphates (PO43-), metaphosphates or pyrophosphates (P2O74-) and occasionally hydrogen or hydroxide ions. ... Apatite is a group of phosphate minerals, usually referring to hydroxylapatite, fluorapatite, and chlorapatite, named for high concentrations of OH-, F-, or Cl- ions, respectively, in the crystal. ...


Instead of bones, sharks have cartilagenous skeletons, with a bone-like layer broken up into thousands of isolated apatite prisms. When a shark dies, the decomposing skeleton breaks up and the apatite prisms scatter. Complete shark skeletons are only preserved when rapid burial in bottom sediments occurs. This article is about the skeletal organs. ... Cartilage is a type of dense connective tissue. ...


Among the most ancient and primitive sharks is Cladoselache, from about 370 million years ago,[15] which has been found within the Paleozoic strata of Ohio, Kentucky and Tennessee. At this point in the Earth's history these rocks made up the soft sediment of the bottom of a large, shallow ocean, which stretched across much of North America. Cladoselache was only about 1 m long with stiff triangular fins and slender jaws.[15] Its teeth had several pointed cusps, which would have been worn down by use. From the number of teeth found in any one place it is most likely that Cladoselache did not replace its teeth as regularly as modern sharks. Its caudal fins had a similar shape to the great white sharks and the pelagic shortfin and longfin makos. The discovery of whole fish found tail first in their stomachs suggest that they were fast swimmers with great agility. Cladoselache is a genus of extinct fish_like shark and is the oldest recognizable shark-like animal. ... The Paleozoic Era (from the Greek palaio, old and zoion, animals, meaning ancient life) is the earliest of three geologic eras of the Phanerozoic eon. ... This article is about the U.S. State. ... Official language(s) English[1] Capital Frankfort Largest city Louisville Area  Ranked 37th  - Total 40,444 sq mi (104,749 km²)  - Width 140 miles (225 km)  - Length 379 miles (610 km)  - % water 1. ... This article is about the U.S. state of Tennessee. ... This article is about Earth as a planet. ... North America North America is a continent[1] in the Earths northern hemisphere and (chiefly) western hemisphere. ... Binomial name (Linnaeus, 1758) Range (in blue) For other uses, see Great White (disambiguation). ... Binomial name Rafinesque, 1810 Range of shortfin mako shark (in blue) The shortfin mako shark, Isurus oxyrinchus, (sharp nose) is a large shark of the Lamnidae family. ... Binomial name Guitart Manday, 1966 Range of longfin mako shark (in blue) The longfin mako, Isurus paucus, is a large shark of the Lamnidae family, found in temperate and tropical seas worldwide. ...


From about 300 to 150 million years ago, most fossil sharks can be assigned to one of two groups. One of these, the acanthuses, was almost exclusive to freshwater environments.[17][18] By the time this group became extinct (about 220 million years ago) they had achieved worldwide distribution. The other group, the hybodonts, appeared about 320 million years ago and was mostly found in the oceans, but also in freshwater. Look up Acanthus in Wiktionary, the free dictionary. ...


Modern sharks began to appear about 100 million years ago.[16] Fossil mackerel shark teeth occurred in the Lower Cretaceous. One of the most recent families of sharks that evolved is the hammerhead sharks (family Sphyrnidae), which emerged in Eocene.[19] The oldest white shark teeth date from 60 to 65 million years ago, around the time of the extinction of the dinosaurs. In early white shark evolution there are at least two lineages: one with coarsely serrated teeth that probably gave rise to the modern great white shark, and another with finely serrated teeth and a tendency to attain gigantic proportions. This group includes the extinct megalodon, Carcharodon megalodon, which like most extinct sharks is only known from its teeth. A reproduction of its jaws was based on some of the largest teeth which were up to almost 17 centimetres (7 in) long and suggested a fish that could grow to a length of 25 metres (80 ft) to 30 metres (100 ft). The reconstruction was found to be inaccurate, and estimates revised downwards to around 13 metres (43 ft) to 15.9 metres (52 ft). The Cretaceous period is one of the major divisions of the geologic timescale, reaching from the end of the Jurassic period (about 135 mya) to the beginning of the Paleocene epoch of the Tertiary period (65 mya). ... Species See text. ... Genera Eusphyra Sphyrna Sphyrnidae is a family of hammerhead sharks containing only two genera, one of which, Eusphyra, contains only one species. ... hfajhfiudshfas == == == --24. ... For the film, see Shark Attack 3: Megalodon. ...


It is believed that the immense size of predatory sharks such as the great white may have arisen from the extinction of the dinosaurs and the diversification of mammals. It is known that at the same time these sharks were evolving some early mammalian groups evolved into aquatic forms. Certainly, wherever the teeth of large sharks have been found, there has also been an abundance of marine mammal bones, including seals, porpoises and whales. These bones frequently show signs of shark attack. There are theories that suggest that large sharks evolved to better take advantage of larger prey. Binomial name (Linnaeus, 1758) Range (in blue) For other uses, see Great White (disambiguation). ... Orders & Suborders Saurischia Sauropodomorpha Theropoda Ornithischia Thyreophora Ornithopoda Marginocephalia Dinosaurs were vertebrate animals that dominated the terrestrial ecosystem for over 160 million years, first appearing approximately 230 million years ago. ... Subclasses & Infraclasses Subclass †Allotheria* Subclass Prototheria Subclass Theria Infraclass †Trituberculata Infraclass Metatheria Infraclass Eutheria Mammals (class Mammalia) are warm-blooded, vertebrate animals characterized by the presence of sweat glands, including those that produce milk, and by the presence of: hair, three middle ear bones used in hearing, and a neocortex... Families Odobenidae Otariidae Phocidae Pinnipeds (fin-feet, lit. ... Genera Neophocaena Phocoena - Harbor porpoises Phocoenoides - Dalls porpoises The porpoises are small cetaceans of the family Phocoenidae; they are related to whales and dolphins. ... Whales are the largest species of exclusively aquatic placental mammals, members of the order Cetacea, which also includes dolphins and porpoises. ...


Classification

Sharks belong to the superorder Selachimorpha in the subclass Elasmobranchii in the class Chondrichthyes. The Elasmobranchii also include rays and skates; the Chondrichthyes also include Chimaeras. It is currently thought that the sharks form a polyphyletic group: in particular, some sharks are more closely related to rays than they are to some other sharks. Image File history File links Download high-resolution version (800x678, 145 KB) Summary Diagram to easliy recognise the 8 extant shark orders Licensing File links The following pages on the English Wikipedia link to this file (pages on other projects are not listed): Shark List of sharks User:Chris huh... Superorders Batoidea (rays and skates) Selachimorpha (sharks) Elasmobranchii is the subclass of cartilaginous fish that includes skates, rays (batoidea) and sharks (selachii). ... Subclasses and Orders See text. ... Orders Rajiformes - common rays and skates Pristiformes - sawfishes Torpediniformes - electric rays See text for families. ... This article is about the fish species. ... Families See text for families, genera and species. ... In phylogenetics, a taxon is polyphyletic (Greek for of many races) if the trait its members have in common evolved separately in different places in the phylogenetic tree. ...


There are more than 360 described species of sharks split across are eight orders of sharks, listed below in roughly their evolutionary relationship from more primitive to more modern species: In scientific classification used in biology, the order (Latin: ordo, plural ordines) is a rank between class and family (termed a taxon at that rank). ...

Families Chlamydoselachidae (frilled shark) Hexanchidae (cow sharks) Hexanchiformes is the order consisting of the most primitive types of sharks, and numbering just a handful of species. ... Species Heptranchias perlo Hexanchus griseus Hexanchus vitulus Notorynchus cepedianus Cow sharks are a family (Hexanchidae) of sharks charatcterized by extra pairs of gill slits. ... Binomial name Chlamydoselachus anguineus Garman, 1884 The frilled shark, Chlamydoselachus anguineus, is a primitive shark species, of the family Chlamydoselachidae in the order Hexanchiformes. ... Families Squalidae (dogfish sharks) Centrophoridae (gulper sharks) Dalatiidae (sleeper sharks) Echinorhinidae (bramble sharks) Squaliformes is an order of sharks that includes the smooth dogfish and spiny dogfish and others, about 80 species in four families. ... This article needs to be cleaned up to conform to a higher standard of quality. ... This article does not cite any references or sources. ... Genera See text. ... The Prickly shark (species Echinorhinus cookei) is a species of shark occurring only in the Pacific Ocean. ... Species Pliotrema warreni Pristiophorus cirratus Pristiophorus japonicus Pristiophorus nudipinnis Pristiophorus schroederi The sawsharks or saw sharks are an order (Pristiophoriformes) of sharks bearing long blade-like snouts edged with teeth, which they use to slash and disable their prey. ... Species See text. ... Species (16 species, see text) The angel sharks are an unusual group of sharks, with their flattened bodies and broad pectoral fins that give them a strong resemblance to skates and rays. ... Species (16 species, see text) The angel sharks are an unusual group of sharks, with their flattened bodies and broad pectoral fins that give them a strong resemblance to skates and rays. ... For other uses, see Stingray (disambiguation). ... Broad skate, Amblyraja badia A skate egg case, known as a mermaids purse. ... Family Heterodontidae (bullhead sharks) The Heterodontiformes are a small order of very basal (primitive) modern sharks (Neoselachii) known colloquially as the bullhead sharks. ... Species See text. ... Binomial name Heterodontus francisci Girard, 1855 The Horn shark (Heterodontus francisci) is a shark from the bullhead shark order Heterodontiformes. ... Families Parascyllidae (collared carpet sharks) Brachaeluridae (blind sharks) Orectolobidae (wobbegongs) Hemiscylliidae (bamboo sharks) Ginglymostomatidae (nurse sharks) Stegostomatidae (zebra shark) Rhincodontidae (whale shark) The order Orectolobiformes, also collectively known as the carpet sharks or wobbegongs (in Australia) because most have carpet-like patterned markings, includes a number of familiar types of... Families Parascyllidae (collared carpet sharks) Brachaeluridae (blind sharks) Orectolobidae (wobbegongs) Hemiscylliidae (bamboo sharks) Ginglymostomatidae (nurse sharks) Stegostomatidae (zebra shark) Rhincodontidae (whale shark) The order Orectolobiformes, also collectively known as the carpet sharks because many members have carpet-like patterned markings, includes a number of familiar types of sharks, such as... This species is sometimes called the leopard shark, a name otherwise used for Triakis semifasciata. ... Binomial name Ginglymostoma cirratum (Bonnaterre, 1788) The nurse shark Ginglymostoma cirratum is a shark in the nurse sharks family and may reach a length of 4. ... Genera Eucrossorhinus Orectolobus Sutorectus Wotwentwong is the common name given to the six species of carpet sharks in the family Orectolobidae. ... Binomial name (Smith, 1828) Range of whale shark The whale shark, Rhincodon typus, is a slow filter feeding shark that is the largest living fish species. ... Families See text. ... Families Scyliorhinidae (cat sharks) Proscyllidae (finback cat sharks) Pseudotriakidae (false cat sharks) Leptochariidae (barbeled houndshark) Triakidae (hound sharks) Hemigaleidae (weasel sharks) Carcharhinidae (requiem sharks) The ground sharks, order Carcharhiniformes, are the largest order of sharks, with over 270 species, and includes a number of common types, such as the blue... Binomial name (Linnaeus, 1758) Range of blue shark The blue shark, Prionace glauca, is a carcharhinid shark which is found in the deep waters of the worlds temperate and tropical oceans. ... For other uses, see Tiger shark (disambiguation). ... Binomial name (Müller and Henle, 1839) Range of bull shark The bull shark, Carcharhinus leucas, also known as the bull whaler, Zambezi shark or informally Zambi in Africa and Nicaragua shark in Nicaragua, is common worldwide in warm, shallow waters along coasts and in rivers. ... Binomial name Carcharhinus amblyrhynchos (Bleeker, 1856) The Gray Reef Shark (Carcharhinus amblyrhynchos) is one of the most common sharks found around coral reefs of Indo-Pacific waters. ... Not to be confused with blacktip shark. ... Binomial name Carcharhinus perezii (Poey, 1876) The Caribbean reef shark, Carcharhinus perezi, is a requiem shark of the family Carcharhinidae found in the tropical western Atlantic and the Caribbean, from Florida and the Bahamas through to Brazil. ... Binomial name Triaenodon obesus (Rüppell, 1837) Not to be confused with oceanic whitetip shark. ... Binomial name (Poey, 1861) Range of oceanic whitetip shark Synonyms Squalus maou, Lesson 1822-1825 Squalus longimanus, Poey 1861 Pterolamiops longimanus Carcharhinus obtusus, Garman 1881 Carcharhinus insularum, Snyder 1904 Pterolamiops magnipinnis, Smith 1958 Pterolamiops budkeri, Fourmanoir 1961 The oceanic whitetip shark, Carcharhinus longimanus, is a large pelagic shark of tropical... Genera Carcharhinus Galeocerdo Glyphis Isogomphodon Lamiopsis Loxodon Nasolamia Negaprion Prionace Rhizoprionodon Scoliodon Sphyrna Triaenodon The requiem sharks are a family (Carcharhinidae) that includes some of the best-known and most common types of sharks, such as the tiger shark, blue shark, bull shark, and milk shark. ... ... Genera Apristurus Asymbolus Atelomycterus Aulohalaelurus Cephaloscyllium Cephalurus Galeus Halaelurus Haplolepharus Holohalaelurus Parmaturus Pentanchus Poroderma Schroederichthys Scyliorhinus The cat sharks or catsharks are a large family (Scyliorhinidae) of sharks, with over 110 species recorded. ... Species See text. ... Families Odontaspididae (sand tigers) Mitsukurinidae (goblin shark) Pseudocarchariidae (crocodile shark) Megachasmidae (megamouth shark) Alopiidae (thresher sharks) Cetorhinidae (basking shark) Lamnidae (mackerel sharks) Great Lamniformes is an order of sharks commonly known as the mackerel sharks. ... Families Odontaspididae (sand tigers) Mitsukurinidae (goblin shark) Pseudocarchariidae (crocodile shark) Megachasmidae (megamouth shark) Alopiidae (thresher sharks) Cetorhinidae (basking shark) Lamnidae (mackerel sharks) Lamniformes is an order of sharks. ... Binomial name Jordan, 1898 Range of the goblin shark (in blue) The goblin shark, Mitsukurina owstoni, is a deep-sea shark, the sole living species in the family Mitsukurinidae. ... Binomial name (Gunnerus, 1765) Range (in blue) The basking shark, Cetorhinus maximus, is the second largest fish, after the whale shark. ... Binomial name Megachasma pelagios Taylor, Compagno and Struhsaker, 1983 The megamouth shark, Megachasma pelagios, is an extremely rare and unusual species of shark, discovered in 1976, with 37 specimens known to be caught or sighted as of 2006. ... Species For species see text. ... Binomial name Rafinesque, 1810 Range of shortfin mako shark (in blue) The shortfin mako shark, Isurus oxyrinchus, (sharp nose) is a large shark of the Lamnidae family. ... Binomial name Guitart Manday, 1966 Range of longfin mako shark (in blue) The longfin mako, Isurus paucus, is a large shark of the Lamnidae family, found in temperate and tropical seas worldwide. ... Binomial name (Linnaeus, 1758) Range (in blue) For other uses, see Great White (disambiguation). ... For the film, see Shark Attack 3: Megalodon. ...

Reproduction

Claspers of male spotted wobbegong, Orectolobus maculatus
Claspers of male spotted wobbegong, Orectolobus maculatus

The sex of a shark can be easily determined. The males have modified pelvic fins which have become a pair of claspers. The name is somewhat misleading as they are not used to hold on to the female, but fulfil the role of the mammalian penis. Image File history File linksMetadata Download high resolution version (1024x768, 99 KB) Claspers of male Spotted Wobbegong shark (Orectolobus maculatus) Location: Shelly Beach, Sydney, Australia Date: 1 January 2005 Photographer: Richard Ling <richard@research. ... Image File history File linksMetadata Download high resolution version (1024x768, 99 KB) Claspers of male Spotted Wobbegong shark (Orectolobus maculatus) Location: Shelly Beach, Sydney, Australia Date: 1 January 2005 Photographer: Richard Ling <richard@research. ... Sexual reproduction is a union that results in increasing genetic diversity of the offspring. ... Human male pelvis, viewed from front Human female pelvis, viewed from front The pelvis is the bony structure located at the base of the spine (properly known as the caudal end). ... In biology, clasper is a body part of male insects that is used to hold the female during copulation. ... The penis (plural penises, penes) is an external male sexual organ. ...


Mating has rarely been observed in sharks. The smaller catsharks often mate with the male curling around the female. In less flexible species the two sharks swim parallel to each other while the male inserts a clasper into the female's oviduct. Females in many of the larger species have bite marks that appear to be a result of a male grasping them to maintain position during mating. The bite marks may also come from courtship behaviour: the male may bite the female to show his interest. In some species, females have evolved thicker skin to withstand these bites. IT FEELS REALLY GOOD IF YOU IMATATE THE ANIMALS. LOL! “Mounting” redirects here. ... In oviparous animals (those that lay eggs), the passage from the ovaries to the outside of the body is known as the oviduct. ...


Sharks have a different reproductive strategy from most fish. Instead of producing huge numbers of eggs and fry (a strategy which can result in a survival rate of less than .01%), sharks normally produce around a dozen pups (blue sharks have been recorded as producing 135 and some species produce as few as two).[20] These pups are either protected by egg cases or born live. Binomial name (Linnaeus, 1758) Range of blue shark The blue shark, Prionace glauca, is a carcharhinid shark which is found in the deep waters of the worlds temperate and tropical oceans. ...

Egg case of Port Jackson shark - found on Vincentia beach, Jervis Bay Territory, Australia
Egg case of Port Jackson shark - found on Vincentia beach, Jervis Bay Territory, Australia

There are three ways in which shark pups are born: Download high resolution version (2048x1536, 627 KB)Egg case of Port Jackson shark. ... Download high resolution version (2048x1536, 627 KB)Egg case of Port Jackson shark. ... Binomial name (Meyer, 1793) Range of Port Jackson shark (in blue) The Port Jackson shark, Heterodontus portusjacksoni, is a type of bullhead shark of the family Heterodontidae, found in the coastal region of southern Australia, including the waters off Port Jackson. ... The Jervis Bay Territory is a territory of the Commonwealth of Australia. ...

  • Oviparity - Some sharks lay eggs. In most of these species, the developing embryo is protected by an egg case with the consistency of leather. Sometimes these cases are corkscrewed into crevices for protection. The mermaid's purse, found washed-up on beaches, is an empty egg case. Oviparous sharks include the horn shark, catshark, Port Jackson shark, and swellshark.[21]
  • Viviparity - These sharks maintain a placental link to the developing young, more analogous to mammalian gestation than that of other fishes. The young are born alive and fully functional. Hammerheads, the requiem sharks (such as the bull and tiger sharks), the basking shark and the smooth dogfish fall into this category. Dogfish have the longest known gestation period of any shark, at 18 to 24 months. Basking sharks and frilled sharks are likely to have even longer gestation periods, but accurate data is lacking.[20]
  • Ovoviviparity - Most sharks utilize this method. The young are nourished by the yolk of their egg and by fluids secreted by glands in the walls of the oviduct. The eggs hatch within the oviduct, and the young continue to be nourished by the remnants of the yolk and the oviduct's fluids. As in viviparity, the young are born alive and fully functional. Some species practice oophagy, where the first embryos to hatch eat the remaining eggs in the oviduct. This practice is believed to be present in all lamniforme sharks, while the developing pups of the grey nurse shark take this a stage further and consume other developing embryos (intrauterine cannibalism). The survival strategy for the species that are ovoviviparous is that the young are able to grow to a comparatively larger size before being born. The whale shark is now considered to be in this category after long having been classified as oviparous. Whale shark eggs found are now thought to have been aborted. Most ovoviviparous sharks give birth in sheltered areas, including bays, river mouths and shallow reefs. They choose such areas because of the protection from predators (mainly other sharks) and the abundance of food.

A Port Jackson sharks egg case. ... Binomial name Heterodontus francisci Girard, 1855 The Horn shark (Heterodontus francisci) is a shark from the bullhead shark order Heterodontiformes. ... Genera Apristurus Asymbolus Atelomycterus Aulohalaelurus Cephaloscyllium Cephalurus Galeus Halaelurus Haplolepharus Holohalaelurus Parmaturus Pentanchus Poroderma Schroederichthys Scyliorhinus The cat sharks or catsharks are a large family (Scyliorhinidae) of sharks, with over 110 species recorded. ... Binomial name (Meyer, 1793) Range of Port Jackson shark (in blue) The Port Jackson shark, Heterodontus portusjacksoni, is a type of bullhead shark of the family Heterodontidae, found in the coastal region of southern Australia, including the waters off Port Jackson. ... The swellshark, Cephaloscyllium ventriosum, is a small shark found in the eastern Pacific Ocean. ... A viviparous animal is an animal employing vivipary, a method of reproduction in which the embryo develops inside the body of the mother from which it gains nourishment, and not from an egg. ... Orders Subclass Monotremata Monotremata Subclass Marsupialia Didelphimorphia Paucituberculata Microbiotheria Dasyuromorphia Peramelemorphia Notoryctemorphia Diprotodontia Subclass Placentalia Xenarthra Dermoptera Desmostylia Scandentia Primates Rodentia Lagomorpha Insectivora Chiroptera Pholidota Carnivora Perissodactyla Artiodactyla Cetacea Afrosoricida Macroscelidea Tubulidentata Hyracoidea Proboscidea Sirenia The mammals are the class of vertebrate animals primarily characterized by the presence of mammary... Species See text. ... Genera Carcharhinus Galeocerdo Glyphis Isogomphodon Lamiopsis Loxodon Nasolamia Negaprion Prionace Rhizoprionodon Scoliodon Sphyrna Triaenodon The requiem sharks are members of the Carcharhinidae family that includes some of the best-known and most common types of sharks, such as the tiger shark, blue shark, bull shark, and milk shark. ... Binomial name (Müller and Henle, 1839) Range of bull shark The bull shark, Carcharhinus leucas, also known as the bull whaler, Zambezi shark or informally Zambi in Africa and Nicaragua shark in Nicaragua, is common worldwide in warm, shallow waters along coasts and in rivers. ... For other uses, see Tiger shark (disambiguation). ... Binomial name (Gunnerus, 1765) Range (in blue) The basking shark, Cetorhinus maximus, is the second largest fish, after the whale shark. ... This article does not cite any references or sources. ... Ovoviviparous animals develop within eggs that remain within the mothers body up until they hatch or are about to hatch. ... Oophagy (egg eating) is the practice of embryos feeding on eggs produced by the ovary while still inside the mothers uterus. ... Binomial name Carcharias taurus Rafinesque, 1810 Not to be confused with nurse shark. ... Three Mormon crickets eating a fourth Mormon cricket In zoology, cannibalism is a common ecological interaction in the animal kingdom and has been recorded for more than 1500 species (this estimate is from 1981, and likely a gross underestimation). ... Binomial name (Smith, 1828) Range of whale shark The whale shark, Rhincodon typus, is a slow filter feeding shark that is the largest living fish species. ...

Asexual reproduction

In December 2001, a pup was born from a female hammerhead shark who had not been in contact with a male shark for over three years. This has led scientists to believe that sharks can produce without the mating process.


After three years of research, this assumption was confirmed on May 23, 2007, after determining the shark born had no paternal DNA, ruling out any sperm-storage theory as previous thought. It is unknown as to the extent of this behaviour in the wild, and how many species of shark are capable of parthenogenesis. This observation in sharks made mammals the only remaining major vertebrate group in which the phenomenon of asexual reproduction has not been observed. is the 143rd day of the year (144th in leap years) in the Gregorian calendar. ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... For the religious belief, see Virgin Birth of Jesus. ...


Scientists warned that this type of behaviour in the wild is rare, and probably a last ditch effort of a species to reproduce when a mate isn't present. This leads to a lack of genetic diversity, required to build defenses against natural threats, and if a species of shark were to rely solely on asexual reproduction, it would probably be a road to extinction and maybe attribute to the decline of blue sharks off the Irish coast.[22] [23] Genetic diversity is a characteristic of ecosystems and gene pools that describes an attribute which is commonly held to be advantageous for survival -- that there are many different versions of otherwise similar organisms. ...


Shark senses

Sense of smell

Sharks have keen olfactory senses, located in the short duct (which is not fused, unlike bony fish) between the anterior and posterior nasal openings, with some species able to detect as little as one part per million of blood in seawater. They are attracted to the chemicals found in the guts of many species, and as a result often linger near or in sewage outfalls. Some species, such as nurse sharks, have external barbels that greatly increase their ability to sense prey. Olfaction, the sense of smell, is the detection of chemicals dissolved in air (or, by animals that breathe water, in water). ... Parts per million (ppm) is a measure of concentration that is used where low levels of concentration are significant. ... Binomial name Ginglymostoma cirratum (Bonnaterre, 1788) The nurse shark Ginglymostoma cirratum is a shark in the nurse sharks family and may reach a length of 4. ... This article is about fish. ...


Sharks generally rely on their superior sense of smell to find prey, but at closer range they also use the lateral lines running along their sides to sense movement in the water, and also employ special sensory pores on their heads (Ampullae of Lorenzini) to detect electrical fields created by prey and the ambient electric fields of the ocean. In fish, the lateral line is a sense organ used to detect movement in the surrounding water. ... The ampullae of Lorenzini are special sensing organs, forming a network of jelly-filled canals found on elasmobranchs (sharks and rays) and Chimaera. ... The article on electrical energy is located elsewhere. ...


Sense of sight

A great white shark at Isla Guadalupe, Mexico is approaching the cage with the divers.
A great white shark at Isla Guadalupe, Mexico is approaching the cage with the divers.

Shark eyes are similar to the eyes of other vertebrates, including similar lenses, corneas and retinas, though their eyesight is well adapted to the marine environment with the help of a tissue called tapetum lucidum. This tissue is behind the retina and reflects light back to the retina, thereby increasing visibility in the dark waters. The effectiveness of the tissue varies, with some sharks having stronger nocturnal adaptations. Sharks have eyelids, but they do not blink because the surrounding water cleans their eyes. To protect their eyes some have nictitating membranes. This membrane covers the eyes during predation, and when the shark is being attacked. However, some species, including the great white shark (Carcharodon carcharias), do not have this membrane, but instead roll their eyes backwards to protect them when striking prey. The importance of sight in shark hunting behaviour is debated. Some believe that electro and chemoreception are more significant, while others point to the nictating membrane as evidence that sight is important. (Presumably, the shark would not protect its eyes were they unimportant.) The degree to which sight is used probably varies with species and water conditions. Image File history File links Size of this preview: 800 × 529 pixelsFull resolution (1536 × 1016 pixel, file size: 906 KB, MIME type: image/jpeg) Please see the file description page for further information. ... Image File history File links Size of this preview: 800 × 529 pixelsFull resolution (1536 × 1016 pixel, file size: 906 KB, MIME type: image/jpeg) Please see the file description page for further information. ... Binomial name (Linnaeus, 1758) Range (in blue) For other uses, see Great White (disambiguation). ... Southeast coast of Guadalupe Island For the French Caribbean island, see Guadeloupe. ... For other uses, see Eye (disambiguation). ... Typical classes Petromyzontidae (lampreys) Placodermi - extinct Chondrichthyes (cartilaginous fish) Acanthodii - extinct Actinopterygii (ray-finned fish) Actinistia (coelacanths) Dipnoi (lungfish) Amphibia (amphibians) Reptilia (reptiles) Aves (birds) Mammalia (mammals) Vertebrata is a subphylum of chordates, specifically, those with backbones or spinal columns. ... Light from a single point of a distant object and light from a single point of a near object being brought to a focus by changing the curvature of the lens. ... The cornea is the transparent front part of the eye that covers the iris, pupil, and anterior chamber, providing most of an eyes optical power [1]. Together with the lens, the cornea refracts light and, as a result, helps the eye to focus. ... Human eye cross-sectional view. ... Animated map exhibiting the worlds oceanic waters. ... A nocturnal animal is one that sleeps during the day and is active at night - the opposite of the human (diurnal) schedule. ... Many species of land animals have a nictitating membrane, which can move across the eyeball to give the sensitive eye structures additional protection in particular circumstances. ... Binomial name (Linnaeus, 1758) Range (in blue) For other uses, see Great White (disambiguation). ...


Sense of hearing

Sharks also have a sharp sense of hearing and can hear prey many miles away. A small opening on each side of their heads (not to be confused with the spiracle) leads directly into the inner ear through a thin channel. The lateral line shows a similar arrangement, as it is open to the environment via a series of openings called lateral line pores. This is a reminder of the common origin of these two vibration- and sound-detecting organs that are grouped together as the acoustico-lateralis system. In bony fish and tetrapods the external opening into the inner ear has been lost. Spiracles are small openings on the surface of animals that usually lead to respiratory systems. ... In fish, the lateral line is a sense organ used to detect movement in the surrounding water. ... Groups See text. ...


Electroreception

Main article: Electroreception
Electroreceptors (Ampullae of Lorenzini) and lateral line canals in the head of a shark.
Electroreceptors (Ampullae of Lorenzini) and lateral line canals in the head of a shark.

The Ampullae of Lorenzini are the electroreceptor organs of the shark, and they vary in number from a couple of hundred to thousands in an individual. Sharks use the Ampullae of Lorenzini to detect the electromagnetic fields that all living things produce. This helps sharks find its prey (mostly the hammer head). The shark has the greatest electricity sensitivity known in all animals. This sense is used to find prey hidden in sand by detecting the electric fields inadvertently produced by all fish. It is this sense that sometimes confuses a shark into attacking a boat: when the metal interacts with salt water, the electrochemical potentials generated by the rusting metal are similar to the weak fields of prey, or in some cases, much stronger than the prey's electrical fields: strong enough to attract sharks from miles away. The oceanic currents moving in the magnetic field of the Earth also generate electric fields that can be used by the sharks for orientation and navigation. Electroreception, sometimes written as electroception, is the biological ability to receive and make use of electrical impulses. ... Image File history File links No higher resolution available. ... Image File history File links No higher resolution available. ... The ampullae of Lorenzini are special sensing organs, forming a network of jelly-filled canals found on elasmobranchs (sharks and rays) and Chimaera. ... This article is about Earth as a planet. ...


Lateral line

Main article: Lateral line

This system is found in most fish, including sharks. It is used to detect motion or vibrations in the water. The shark uses this to detect the movements of other organisms, especially wounded fish. The shark can sense frequencies in the range of 25 to 50 Hz.[24] In fish, the lateral line is a sense organ used to detect movement in the surrounding water. ... This article is about the SI unit of frequency. ...


Behavior

This seal at California beach was killed by a shark (probably a Great White Shark)
This seal at California beach was killed by a shark (probably a Great White Shark)

Studies on the behavior of sharks have only recently been carried out leading to little information on the subject, although this is changing. The classic view of the shark is that of a solitary hunter, ranging the oceans in search of food; however, this is only true for a few species, with most living far more sedentary, benthic lives. Even solitary sharks meet for breeding or on rich hunting grounds, which may lead them to cover thousands of miles in a year.[25] Migration patterns in sharks may be even more complex than in birds, with many sharks covering entire ocean basins. Image File history File links Metadata Size of this preview: 800 × 533 pixelsFull resolution (3888 × 2592 pixel, file size: 8. ... Image File history File links Metadata Size of this preview: 800 × 533 pixelsFull resolution (3888 × 2592 pixel, file size: 8. ... Official language(s) English Capital Sacramento Largest city Los Angeles Largest metro area Greater Los Angeles Area  Ranked 3rd  - Total 158,302 sq mi (410,000 km²)  - Width 250 miles (400 km)  - Length 770 miles (1,240 km)  - % water 4. ... Binomial name (Linnaeus, 1758) Range (in blue) For other uses, see Great White (disambiguation). ... Oceanic basin can also refer to the river basins flowing into an ocean. ...


Some sharks can be highly social, remaining in large schools, sometimes up to over 100 individuals for scalloped hammerheads congregating around seamounts and islands e.g. in the Gulf of California.[6] Cross-species social hierarchies exist with oceanic whitetip sharks dominating silky sharks of comparable size when feeding. Binomial name Sphyrna lewini The Scalloped Hammerhead is a member of the hammerhead family originally called Zygaena lewini, but was later renamed to its current name, Sphyrna lewini. ... A seamount is a mountain rising from the ocean seafloor that does not reach to the waters surface (sea level), and thus is not an island. ... The Gulf of California (also known as the Sea of Cortez or Sea of Cortés; locally known in the Spanish language as Mar de Cortés or, much less frequently, Golfo de California) is a body of water that separates the Baja California Peninsula from the Mexican mainland. ... Binomial name (Poey, 1861) Range of oceanic whitetip shark Synonyms Squalus maou, Lesson 1822-1825 Squalus longimanus, Poey 1861 Pterolamiops longimanus Carcharhinus obtusus, Garman 1881 Carcharhinus insularum, Snyder 1904 Pterolamiops magnipinnis, Smith 1958 Pterolamiops budkeri, Fourmanoir 1961 The oceanic whitetip shark, Carcharhinus longimanus, is a large pelagic shark of tropical... Binomial name Carcharias falciformis (Müller & Henle, 1839) The silky shark (Carcharias falciformis) is a large pelagic shark of tropical and warm temperate seas. ...


When approached too closely some sharks will perform a threat display to warn off the prospective predators. This usually consists of exaggerated swimming movements, and can vary in intensity according to the level of threat.[26] Threat display of a grey reef shark. ...


Shark intelligence

Despite the common myth that sharks are instinct-driven "eating machines", recent studies have indicated that many species possess powerful problem-solving skills, social complexity and curiosity. The brain-mass-to-body-mass ratios of sharks are similar to those of mammals and other higher vertebrate species.[27]


In 1987, near Smitswinkle Bay, South Africa, a group of up to seven great white sharks worked together to relocate the partially beached body of a dead whale to deeper waters to feed.[28] Binomial name (Linnaeus, 1758) Range (in blue) For other uses, see Great White (disambiguation). ...


Sharks have even been known to engage in playful activities (a trait also observed in cetaceans and primates). Porbeagle sharks have been seen repeatedly rolling in kelp and have even been observed chasing an individual trailing a piece behind them.[29] Suborders Mysticeti Odontoceti (see text) The order Cetacea includes whales, dolphins and porpoises. ... For the ecclesiastical use of this term, see primate (religion) Families 13, See classification A primate is any member of the biological order Primates, the group that contains all lemurs, monkeys, and apes, including humans. ... Binomial name Bonnaterre, 1788 Range of porbeagle (in blue) The porbeagle, Lamna nasus, is a large pelagic predatory shark of the family Lamnidae. ...


Shark sleep

Some say a shark never sleeps. It is unclear how sharks sleep. Some sharks can lie on the bottom while actively pumping water over their gills, but their eyes remain open and actively follow divers. When a shark is resting, they do not use their nares, but rather their spiracles. If a shark tried to use their nares while resting on the ocean floor, they would be sucking up sand rather than water. Many scientists believe this is one of the reasons sharks have spiracles. The spiny dogfish's spinal cord, rather than its brain, coordinates swimming, so it is possible for a spiny dogfish to continue to swim while sleeping. This article is about nares, the scientific term for a birds or a frogs([[for Mr. ... Spiracles are small openings on the surface of animals that usually lead to respiratory systems. ... Binomial name Squalus acanthias Linnaeus, 1758 The spiny dogfish or piked dogfish, Squalus acanthias, is one of the best known of the dogfish, members of the family Squalidae in the order Squaliformes. ... The Spinal cord nested in the vertebral column. ... Binomial name Squalus acanthias Linnaeus, 1758 The spiny dogfish or piked dogfish, Squalus acanthias, is one of the best known of the dogfish, members of the family Squalidae in the order Squaliformes. ...


It is also possible that a shark can sleep in a manner similar to dolphins.[30] In this situation, one half of the brain sleeps at a time, thereby allowing the shark to be half conscious while sleeping. This article is about the dolphin mammal. ...


Habitat

A December 10, 2006 report by the Census of Marine Life group reveals that 70% of the world's oceans are shark-free. They have discovered that although many sharks live up to depths as low as 1,500 metres (5,000 ft), they fail to colonize deeper, putting them more easily within reach of fisheries and thus endangered status.[31] The Census of Marine Life (CoML) is an ambitious, 10-year program with the aim of answering three basic questions, what lives in the oceans (current and near-current data); what did live in the oceans (historical data); and what will live in the oceans (predictive / modelled data). ...


Shark attacks

Snorkeler with blacktip reef shark. In rare circumstances involving poor visibility, blacktips may bite a human, mistaking it for prey. Under normal conditions they are harmless and shy.
Snorkeler with blacktip reef shark. In rare circumstances involving poor visibility, blacktips may bite a human, mistaking it for prey. Under normal conditions they are harmless and shy.
Main article: Shark attack

Sharks rarely attack humans unless provoked. In 2006 the International Shark Attack File (ISAF) undertook an investigation into 96 alleged shark attacks, confirming 62 of them as unprovoked attacks and 16 as provoked attacks. The average number of fatalities per year between 2001 and 2006 from unprovoked shark attacks is 4.3.[32] Image File history File links Download high resolution version (1000x517, 319 KB) Snorkeler with Blacktip reef shark (Carcharhinus melanopterus). ... Image File history File links Download high resolution version (1000x517, 319 KB) Snorkeler with Blacktip reef shark (Carcharhinus melanopterus). ... Not to be confused with blacktip shark. ... For the film, see Shark Attack (film). ... The International Shark Attack File is a global database of shark attacks. ...


Contrary to popular belief, only a few sharks are dangerous to humans. Out of more than 360 species, only four have been involved in a significant number of fatal, unprovoked attacks on humans: the great white, tiger, oceanic whitetip and bull sharks.[33] [34] These sharks, being large, powerful predators, may sometimes attack and kill people, but all of these sharks have been filmed in open water, without the use of a protective cage.[35] Binomial name (Linnaeus, 1758) Range (in blue) For other uses, see Great White (disambiguation). ... For other uses, see Tiger shark (disambiguation). ... Binomial name (Poey, 1861) Range of oceanic whitetip shark Synonyms Squalus maou, Lesson 1822-1825 Squalus longimanus, Poey 1861 Pterolamiops longimanus Carcharhinus obtusus, Garman 1881 Carcharhinus insularum, Snyder 1904 Pterolamiops magnipinnis, Smith 1958 Pterolamiops budkeri, Fourmanoir 1961 The oceanic whitetip shark, Carcharhinus longimanus, is a large pelagic shark of tropical... Binomial name (Müller and Henle, 1839) Range of bull shark The bull shark, Carcharhinus leucas, also known as the bull whaler, Zambezi shark or informally Zambi in Africa and Nicaragua shark in Nicaragua, is common worldwide in warm, shallow waters along coasts and in rivers. ...


The perception of sharks as dangerous animals has been popularised by publicity given to a few isolated unprovoked attacks, such as the Jersey Shore shark attacks of 1916, and through popular fictional works about shark attacks, such as the Jaws film series. The author of Jaws, Peter Benchley, had in his later years attempted to dispel the image of sharks as man-eating monsters. The Philadelphia Inquirer reported the capture of a man-eating shark off the Jersey Shore after the attacks. ... Jaws is a 1975 thriller film directed by Steven Spielberg, based on Peter Benchleys best-selling novel inspired by the Jersey Shore shark attacks of 1916. ... Peter Bradford Benchley (May 8, 1940 – February 11, 2006) was an American author best known for writing the novel Jaws and co-writing the screenplay for its highly successful film adaptation. ...


Sharks in captivity

Until recently only a few benthic species of shark, such as hornsharks, leopard sharks and catsharks could survive in aquarium conditions for up to a year or more. This gave rise to the belief that sharks, as well as being difficult to capture and transport, were difficult to care for. A better knowledge of sharks has led to more species (including the large pelagic sharks) being able to be kept for far longer. At the same time, transportation techniques have improved and now provide a way for the long distance movement of sharks.[36] The only species of shark to have never been successfully held in captivity was the great white, until September 2004 when the Monterey Bay Aquarium successfully kept a young female great white shark for 198 days before releasing her back into the wild. Image File history File linksMetadata Download high-resolution version (1596x1013, 1041 KB) Summary Two Whale Sharks in the Okinawa Churaumi Aquarium Location: 424 Ishikawa, Motobu-cho, Kunigami-gun, Okinawa Japan 905-0206 Photo by Derek Mawhinney January 17, 2004 Licensing File history Legend: (cur) = this is the current file, (del... Image File history File linksMetadata Download high-resolution version (1596x1013, 1041 KB) Summary Two Whale Sharks in the Okinawa Churaumi Aquarium Location: 424 Ishikawa, Motobu-cho, Kunigami-gun, Okinawa Japan 905-0206 Photo by Derek Mawhinney January 17, 2004 Licensing File history Legend: (cur) = this is the current file, (del... Binomial name (Smith, 1828) Range of whale shark The whale shark, Rhincodon typus, is a slow filter feeding shark that is the largest living fish species. ... People silhouetted in front of the aquarium panel The Okinawa Churaumi Aquarium (沖縄美ら海水族館, Okinawa churaumi suizokukan) is the worlds second largest aquarium. ... In marine geology and biology, benthos are the organisms and habitats of the sea floor; in freshwater biology they are the organisms and habitats of the bottoms of lakes, rivers, and creeks. ... Binomial name Heterodontus francisci Girard, 1855 The Horn shark (Heterodontus francisci) is a shark from the bullhead shark order Heterodontiformes. ... Binomial name Triakis semifasciata Girard, 1855 The leopard shark, Triakis semifasciata, is a hound shark found in the coastal waters of the eastern Pacific Ocean, along the coast of North America from Oregon to Baja California. ... Genera Apristurus Asymbolus Atelomycterus Aulohalaelurus Cephaloscyllium Cephalurus Galeus Halaelurus Haplolepharus Holohalaelurus Parmaturus Pentanchus Poroderma Schroederichthys Scyliorhinus The cat sharks or catsharks are a large family (Scyliorhinidae) of sharks, with over 110 species recorded. ... The pelagic zone is the part of the open sea or ocean comprising the water column, i. ...


Despite being considered critical for the health of the shark, very few studies on feeding have been carried out. Since food is the reward for appropriate behaviour, trainers must rely on control of feeding motivation.


Conservation

Sharks jaws for sale at Madagascar store
Sharks jaws for sale at Madagascar store
The number of sharks being caught has increased rapidly over the last 50 years.

The majority of shark fisheries around the globe have little monitoring or management. With the rise in demand of shark products there is a greater pressure on fisheries.[37] Stocks decline and collapse because sharks are long-lived apex predators with comparatively small populations, which makes it difficult for them breed rapidly enough to maintain population levels. Major declines in shark stocks have been recorded in recent years - some species have been depleted by over 90% over the past 20-30 years with a population decline of 70% not being unusual.[38] Many governments and the UN have acknowledged the need for shark fisheries management, but due to the low economic value of shark fisheries, the small volumes of products produced and the poor public image of sharks, little progress has been made. Image File history File links Metadata Size of this preview: 800 × 531 pixelsFull resolution (2048 × 1360 pixel, file size: 1. ... Image File history File links Metadata Size of this preview: 800 × 531 pixelsFull resolution (2048 × 1360 pixel, file size: 1. ... Image File history File links Global_shark_catch_graph_1950_to_2004. ... Image File history File links Global_shark_catch_graph_1950_to_2004. ... This article is about the United Nations, for other uses of UN see UN (disambiguation) Official languages English, French, Spanish, Russian, Chinese, Arabic Secretary-General Kofi Annan (since 1997) Established October 24, 1945 Member states 191 Headquarters New York City, NY, USA Official site http://www. ...


Many other threats to sharks include habitat alteration, damage and loss from coastal developments, pollution and the impact of fisheries on the seabed and prey species.


A Canadian-made documentary, Sharkwater is raising awareness of the depletion of the world's shark population. // Sharkwater is a Canadian Documentary film directed, written, and starred in, by Rob Stewart. ...


Shark fishery

A 14-foot (4 m), 544 kg (1200 pound) Tiger shark caught in Kaneohe Bay, Oahu in 1966
A 14-foot (4 m), 544 kg (1200 pound) Tiger shark caught in Kaneohe Bay, Oahu in 1966

Every year, an estimate states that 26 to 73 million (median value is at 38 million) sharks are killed by people in commercial and recreational fishing.[39] In the past, sharks were killed simply for the sport of landing a good fighting fish (such as the shortfin mako sharks). Shark skin is covered with dermal denticles, which are similar to tiny teeth, and was used for purposes similar to sandpaper. Other sharks are hunted for food (Atlantic thresher, shortfin mako and others), and some species for other products.[40] Image File history File links Size of this preview: 396 × 599 pixelsFull resolution (1164 × 1760 pixel, file size: 1. ... Image File history File links Size of this preview: 396 × 599 pixelsFull resolution (1164 × 1760 pixel, file size: 1. ... For other uses, see Tiger shark (disambiguation). ... K&#257;neohe Bay, at 45 km2, is the largest sheltered body of water in the main Hawaiian Islands. ... Oʻahu (usually Oahu outside Hawaiian and Hawaiian English), the Gathering Place, is the third largest of the Hawaiian Islands and most populous island in the State of Hawaiʻi. ...


Sharks are a common seafood in many places around the world, including Japan and Australia. In the Australian State of Victoria shark is the most commonly used fish in fish and chips, in which fillets are battered and deep-fried or crumbed and grilled and served alongside chips. When served in fish and chip shops, it is called flake. VIC redirects here. ... Fish and chips in modern packaging Fish and chips or fish n chips, a popular take-away food with British origins, consists of deep-fried fish in batter or breadcrumbs with deep-fried potatoes. ... Flake is a term used in Australia to indicate the flesh of any of several species of small shark, particularly Scrummy Shark. ...


Sharks are often killed for shark fin soup: the finning process involves capture of a live shark, the removal of the fin with a hot metal blade, and the release of the live animal back into the water. Sharks are also killed for their meat. Conservationists have campaigned for changes in the law to make finning illegal in the U.S. The meat of dogfishes, smoothhounds, catsharks, makos, porbeagle and also skates and rays are in high demand by European consumers.[41] Shark fin soup A dried shark fin prepared for cooking Shark fins and other shark parts for sale in a Chinese pharmacy Shark fin soup (Chinese: 魚翅; Jyutping: jyu4 ci3, Mandarin: (Pinyin) Yú Chì / (Wade-Giles) Yü Chih4 ) is a Chinese delicacy commonly served as part of a Chinese feast...


Shark cartilage has been advocated as effective against cancer and for treatment of osteoarthritis. (This is because many people believe that sharks cannot get cancer and that taking it will prevent people from getting these diseases, which is untrue.) However, a trial by Mayo Clinic found no effect in advanced cancer patients. Shark cartilage is a popular dietary supplement used to combat and/or prevent a variety of illnesses, most notably cancer. ... Cancer is a class of diseases or disorders characterized by uncontrolled division of cells and the ability of these to spread, either by direct growth into adjacent tissue through invasion, or by implantation into distant sites by metastasis (where cancer cells are transported through the bloodstream or lymphatic system). ... Osteoarthritis (OA, also known as degenerative arthritis, degenerative joint disease, or in more colloquial terms wear and tear), is a condition in which low-grade inflammation results in pain in the joints, caused by wearing of the cartilage that covers and acts as a cushion inside joints and destruction or... Main campus in downtown Rochester, Minnesota. ...


Sharks generally reach sexual maturity slowly and produce very few offspring in comparison to other fish that are harvested. This has caused concern among biologists regarding the increase in effort applied to catching sharks over time, and many species are considered to be threatened.


Some organizations, such as the Shark Trust, campaign to limit shark fishing. Shark Trust Logo The Shark Trust is a charitable organization founded in 1997 that encourages the conservation of shark, and promotes the international study, managment and conservation of sharks, skates and rays. ...


Sharks in mythology

Sharks figure prominently in the Hawaiian mythology. There are stories of shark men who have shark jaws on their back. They could change form between shark and human at any time they desired. A common theme in the stories was that the shark men would warn beach-goers that sharks were in the waters. The beach-goers would laugh and ignore the warnings and go swimming, subsequently being eaten by the same shark man who warned them not to enter the water. Hawaiian mythology is a variant of a more general Polynesian mythology. ...


Hawaiian mythology also contained many shark gods. They believed that sharks were guardians of the sea, and called them Aumakua:[42]
This article discusses the term God in the context of monotheism and henotheism. ...

  • Kamohoali'i - The best known and revered of the shark gods, he was the older and favoured brother of Pele,[43] and helped and journeyed with her to Hawaii. He was able to take on all human and fish forms. A summit cliff on the crater of Kilauea is considered to be one of his most sacred spots. At one point he had a he'iau (temple or shrine) dedicated to him on every piece of land that jutted into the ocean on the island of Moloka'i.
  • Ka'ahupahau - This goddess was born human, with her defining characteristic being her red hair. She was later transformed into shark form and was believed to protect the people who lived on O'ahu from sharks. She was also believed to live near Pearl Harbor.
  • Kaholia Kane - This was the shark god of the ali'i Kalaniopu'u and he was believed to live in a cave at Puhi, Kaua'i.
  • Kane'ae - The shark goddess who transformed into a human in order to experience the joy of dancing.
  • Kane'apua - Most commonly, he was the brother of Pele and Kamohoali'i. He was a trickster god who performed many heroic feats, including the calming of two legendary colliding hills that destroyed canoes trying to pass between.
  • Kawelomahamahai'a - Another human, he was transformed into a shark.
  • Keali'ikau 'o Ka'u - He was the cousin of Pele and son of Kua. He was called the protector of the Ka'u people. He had an affair with a human girl, who gave birth to a helpful green shark.
  • Kua - This was the main shark god of the people of Ka'u, and believed to be their ancestor.
  • Kuhaimoana - He was the brother of Pele and lived in the Ka'ula islet. He was said to be 30 fathoms (55 m) long and was the husband of Ka'ahupahau.
  • Kauhuhu - He was a fierce king shark that lived in a cave in Kipahulu on the island of Maui. He sometimes moved to another cave on the windward side of island of Moloka'i.
  • Kane-i-kokala - A kind shark god that saved shipwrecked people by taking them to shore. The people who worshipped him feared to eat, touch or cross the smoke of the kokala, his sacred fish.

In other Pacific Ocean cultures, Dakuwanga was a shark god who was the eater of lost souls. In Hawaiian mythology, Pele is a goddess of fire, lightning, dance, volcanoes and violence, a daughter of Haumea and Kane Milohai. ... This article is about the U.S. State. ... This article is about the harbor in Hawaii. ...


Sharks in cultural tradition

In ancient Greece, it was forbidden to eat shark flesh at women's festivals.


A popular myth is that sharks are immune to disease and cancer; however, this is untrue. There are both diseases and parasites that affect sharks. The evidence that sharks are at least resistant to cancer and disease is mostly anecdotal and there have been few, if any, scientific or statistical studies that have shown sharks to have heightened immunity to disease.[44] Cancer is a class of diseases or disorders characterized by uncontrolled division of cells and the ability of these to spread, either by direct growth into adjacent tissue through invasion, or by implantation into distant sites by metastasis (where cancer cells are transported through the bloodstream or lymphatic system). ... A parasite is an organism that lives in or on the living tissue of a host organism at the expense of it. ... An anecdote is a short tale told about an interesting, amusing, or biographical incident. ... For Wikipedia statistics, see m:Statistics Statistics is the science and practice of developing human knowledge through the use of empirical data expressed in quantitative form. ...


In popular culture

Films

 20,000 Leagues Under the Sea is a 1954 film starring Kirk Douglas as Ned Land, James Mason as Captain Nemo, Paul Lukas as Professor Aronnax and Peter Lorre as Conseil. ... For other topics with this name, see Thunderball. ... Jaws is a 1975 thriller film directed by Steven Spielberg, based on Peter Benchleys best-selling novel inspired by the Jersey Shore shark attacks of 1916. ... Live and Let Die is the 8th film in the British James Bond series and the first to star Roger Moore as MI6 agent James Bond. ... For the James Bond film, see The Spy Who Loved Me (film). ... Cover of the movie Tintorera Tintorera is a Mexican horror movie (1977) directed by René Cardona Jr and based on the novel of the same name of Ramón Bravo oceanographer that studied the species of shark known as Tintorera (a 7 ft shark) and discovered the sleeping sharks. ... The poster of Great White Great White (original title: LUltimo Squalo) is an Italian 1980 horror film by Enzo G. Castellari. ... Cruel Jaws is a 1995 film that was made as a knock-off of the Jaws film series. ... Deep Blue Sea is a 1999 science fiction horror film that stars Thomas Jane, Samuel L. Jackson, and Saffron Burrows. ... This article covers the Shark Attack trilogy films — the plots, facts both good and bad, and the death of the sharks. ... Open Water is a 2003 film inspired by a true story about an American couple, Tom and Eileen Lonergan, who in 1998 went out with a scuba diving group, Outer Edge Dive Company, into the South Pacific. ... Red Water aired on Turner Broadcast System(TBS) in August of 2003 and became one of the highest-rated movies in the stations history. ... Finding Nemo is an Academy Award-winning computer-animated film produced by Pixar Animation Studios and released to theaters by Walt Disney Pictures and Buena Vista Distribution. ... Shark Tale is an Academy Award-nominated computer-animated film produced by DreamWorks Animation, and released in 2004. ... The Life Aquatic with Steve Zissou is Wes Andersons fourth feature length film and was released in the U.S. on December 25, 2004. ... This article does not cite any references or sources. ... Shark Bait (The Reef in the UK, Pis Story in South Korea) is a 2006 computer animated film. ... Sharkwater is a 2007 Canadian documentary film directed, written, and starred in, by Rob Stewart. ...

Books

  • Megalodon Robin Brown (1983)
  • Jaws Peter Benchley (1974)
  • Deep Wizardry Diane Duane (1985)
  • Carcharodon George Edward Noe (1987)
  • Meg: A Novel of Deep Terror Steve Alten (1997)
  • The Trench Steve Alten (1999)
  • Meg: Primal Waters Steve Alten (2004)

Deep Wizardry is the second book in the Young Wizards series by Diane Duane. ... lisa Belkova woz ehe! ...

See also

// Sharks belong to the superorder Selachimorpha in the subclass Elasmobranchii in the class Chondrichthyes. ...

References

  1. ^ a b Budker, Paul (1971). The Life of Sharks. London: Weidenfeld and Nicolson. SBN 297003070. 
  2. ^ Allen, Thomas B. (1999). The Shark Almanac. New York: The Lyons Press. ISBN 1-55821-582-4. 
  3. ^ Hamlett, W. C. (1999). Sharks, Skates and Rays: The Biology of Elasmobranch Fishes. Johns Hopkins University Press. ISBN 0-8018-6048-2. 
  4. ^ a b Gilbertson, Lance (1999). Zoology Laboratory Manual. New York: McGraw-Hill Companies, Inc.. ISBN 0-07-237716-X. 
  5. ^ William J. Bennetta (1996). Deep Breathing. Retrieved on 2007-08-28.
  6. ^ a b c Compagno, Leonard; Dando, Marc & Fowler, Sarah (2005). Sharks of the World. Collins Field Guides. ISBN 0-00-713610-2. 
  7. ^ Pratt, H. L. Jr; Gruber, S. H.; & Taniuchi, T. (1990). Elasmobranchs as living resources: Advances in the biology, ecology, systematics, and the status of the fisheries. NOAA Tech Rept.. 
  8. ^ a b Nelson, Joseph S. (1994). Fishes of the World. New York: John Wiley and Sons. ISBN 0-471-54713-1. 
  9. ^ R. Aidan Martin. Skin of the Teeth. Retrieved on 2007-08-28.
  10. ^ Mote Marine Laboratory, "Shark Notes".
  11. ^ Florida Museum of Natural History Ichthyology Department, "National Shark Research Consortium - Shark Basics".
  12. ^ Online Etymology Dictionary. Retrieved on 2006-08-08.
  13. ^ Marx, Robert F. (1990). The History of Underwater Exploration. Courier Dover Publications, 3. ISBN 0-486-26487-4. 
  14. ^ Martin, R. Aidan.. Geologic Time. ReefQuest. Retrieved on 2006-09-09.
  15. ^ a b c Martin, R. Aidan.. Ancient Sharks. ReefQuest. Retrieved on 2006-09-09.
  16. ^ a b Martin, R. Aidan.. The Origin of Modern Sharks. ReefQuest. Retrieved on 2006-09-09.
  17. ^ http://hoopermuseum.earthsci.carleton.ca/sharks/P2-3.htm "Xenacanth". Retrieved on 11/26/06.
  18. ^ http://www.elasmo-research.org/education/evolution/earliest.htm "Biology of Sharks and Rays: 'The Earliest Sharks'". Retrieved on 11/26/06.
  19. ^ R. Aidan Martin. The Rise of Modern Sharks. Retrieved on 2007-08-28.
  20. ^ a b Leonard J. V. Compagno (1984). Sharks of the World: An annotated and illustrated catalogue of shark species known to date. Food and Agriculture Organization of the United Nations. ISBN 92-5-104543-7. 
  21. ^ Marine Biology notes. School of Life Sciences, Napier University. Retrieved on 2006-09-12.
  22. ^ Female sharks reproduce without male DNA, scientists say. The New York Times, New York City. Retrieved on 2007-11-13.
  23. ^ Demian D. Chapman1, Mahmood S. Shivji, Ed Louis, Julie Sommer, Hugh Fletcher and Paulo A. Prodöhl. Virgin birth in a hammerhead shark. Biology Letters. Retrieved on 2007-05-25.
  24. ^ Popper, A.N.; C. Platt (1993). "Inner ear and lateral line". The Physiology of Fishes (1st ed.). CRC Press. 
  25. ^ Scientists track shark's 12,000 mile round-trip. Guardian Unlimited. Retrieved on 2006-09-17.
  26. ^ Jaws: The natural history of sharks. Natural History Museum. Retrieved on 2006-09-17.
  27. ^ Smart sharks. BBC - Science and nature. Retrieved on 2006-08-07.
  28. ^ Is the White Shark Intelligent. ReefQuest Centre for Shark Research. Retrieved on 2006-08-07.
  29. ^ Biology of the Porbeagle. ReefQuest Centre for Shark Research. Retrieved on 2006-08-07.
  30. ^ How Do Sharks Swim When Asleep?. ReefQuest Centre for Shark Research. Retrieved on 2006-08-07.
  31. ^ Extreme Life, Marine Style, Highlights 2006 Ocean Census. coml.org (2006-12-10). Retrieved on 2006-12-10.
  32. ^ Worldwide shark attack summary. International Shark Attack File. Retrieved on 2007-08-28.
  33. ^ Statistics on Attacking Species of Shark. ISAF. Retrieved on 2006-09-12.
  34. ^ Biology of sharks and rays. ReefQuest Centre for Shark Research. Retrieved on 2007-11-21.
  35. ^ Great white shark spotted off Hale'iwa. Hawaiian newspaper article. Retrieved on 2006-09-12. with pictures of cageless diver with great white shark.
  36. ^ Whale Sharks in Captivity. Retrieved on 2006-09-13.
  37. ^ Pratt, H. L. Jr.; Gruber, S. H. & Taniuchi, T. (1990). Elasmobranchs as living resources: Advances in the biology, ecology, systematics, and the status of the fisheries. NOAA Tech Rept. (90). 
  38. ^ Walker, T.I. (1998). Shark Fisheries Management and Biology. 
  39. ^ Triple Threat: World Fin Trade May Harvest up to 73 Million Sharks per Year. Retrieved on 2007-10-07.
  40. ^ FAO Shark Fisheries. Retrieved on 2006-09-10.
  41. ^ [http://www.sharkalliance.org/do_download.asp?did=1090 Shark fisheries and trade in Europe: Fact sheet on Italy]. Retrieved on 2007-09-06.
  42. ^ Hawaiian Mythology. Retrieved on 2006-09-13.
  43. ^ Pele, Goddess of Fire. Retrieved on 2006-09-13.
  44. ^ Do Sharks Hold Secret to Human Cancer Fight?. National Geographic. Retrieved on 2006-09-08.
General references
  • Castro, Jose (1983). The Sharks of North American Waters. College Station: Texas A&M University Press. ISBN 0-89096-143-3. 
  • Stevens, John D. (1987). Sharks. New York: NY Facts on File Publications. ISBN 0-8160-1800-6. 
  • Pough, F. H.; Janis, C. M. & Heiser, J. B. (2005). Vertebrate Life. 7th Ed.. New Jersey: Pearson Education Ltd.. ISBN 0-13-127836-3. 
  • Clover, Charles. 2004. The End of the Line: How overfishing is changing the world and what we eat. Ebury Press, London. ISBN 0-09-189780-7

Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... is the 240th day of the year (241st in leap years) in the Gregorian calendar. ... Fishes of the World by Joseph S. Nelson is a standard reference for fish systematics. ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... is the 240th day of the year (241st in leap years) in the Gregorian calendar. ... Year 2006 (MMVI) was a common year starting on Sunday of the Gregorian calendar. ... is the 220th day of the year (221st in leap years) in the Gregorian calendar. ... Year 2006 (MMVI) was a common year starting on Sunday of the Gregorian calendar. ... is the 252nd day of the year (253rd in leap years) in the Gregorian calendar. ... Year 2006 (MMVI) was a common year starting on Sunday of the Gregorian calendar. ... is the 252nd day of the year (253rd in leap years) in the Gregorian calendar. ... Year 2006 (MMVI) was a common year starting on Sunday of the Gregorian calendar. ... is the 252nd day of the year (253rd in leap years) in the Gregorian calendar. ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... is the 240th day of the year (241st in leap years) in the Gregorian calendar. ... Year 2006 (MMVI) was a common year starting on Sunday of the Gregorian calendar. ... is the 255th day of the year (256th in leap years) in the Gregorian calendar. ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... is the 317th day of the year (318th in leap years) in the Gregorian calendar. ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... is the 145th day of the year (146th in leap years) in the Gregorian calendar. ... Year 2006 (MMVI) was a common year starting on Sunday of the Gregorian calendar. ... is the 260th day of the year (261st in leap years) in the Gregorian calendar. ... For other similarly-named museums see Museum of Natural History. ... Year 2006 (MMVI) was a common year starting on Sunday of the Gregorian calendar. ... is the 260th day of the year (261st in leap years) in the Gregorian calendar. ... Year 2006 (MMVI) was a common year starting on Sunday of the Gregorian calendar. ... is the 219th day of the year (220th in leap years) in the Gregorian calendar. ... Year 2006 (MMVI) was a common year starting on Sunday of the Gregorian calendar. ... is the 219th day of the year (220th in leap years) in the Gregorian calendar. ... Year 2006 (MMVI) was a common year starting on Sunday of the Gregorian calendar. ... is the 219th day of the year (220th in leap years) in the Gregorian calendar. ... Year 2006 (MMVI) was a common year starting on Sunday of the Gregorian calendar. ... is the 219th day of the year (220th in leap years) in the Gregorian calendar. ... Year 2006 (MMVI) was a common year starting on Sunday of the Gregorian calendar. ... is the 344th day of the year (345th in leap years) in the Gregorian calendar. ... Year 2006 (MMVI) was a common year starting on Sunday of the Gregorian calendar. ... is the 344th day of the year (345th in leap years) in the Gregorian calendar. ... The International Shark Attack File is a global database of shark attacks. ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... is the 240th day of the year (241st in leap years) in the Gregorian calendar. ... Year 2006 (MMVI) was a common year starting on Sunday of the Gregorian calendar. ... is the 255th day of the year (256th in leap years) in the Gregorian calendar. ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... is the 325th day of the year (326th in leap years) in the Gregorian calendar. ... Year 2006 (MMVI) was a common year starting on Sunday of the Gregorian calendar. ... is the 255th day of the year (256th in leap years) in the Gregorian calendar. ... Year 2006 (MMVI) was a common year starting on Sunday of the Gregorian calendar. ... is the 256th day of the year (257th in leap years) in the Gregorian calendar. ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... is the 280th day of the year (281st in leap years) in the Gregorian calendar. ... Year 2006 (MMVI) was a common year starting on Sunday of the Gregorian calendar. ... is the 253rd day of the year (254th in leap years) in the Gregorian calendar. ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... is the 249th day of the year (250th in leap years) in the Gregorian calendar. ... Year 2006 (MMVI) was a common year starting on Sunday of the Gregorian calendar. ... is the 256th day of the year (257th in leap years) in the Gregorian calendar. ... Year 2006 (MMVI) was a common year starting on Sunday of the Gregorian calendar. ... is the 256th day of the year (257th in leap years) in the Gregorian calendar. ... Year 2006 (MMVI) was a common year starting on Sunday of the Gregorian calendar. ... is the 251st day of the year (252nd in leap years) in the Gregorian calendar. ...

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  Results from FactBites:
 
Sharks: Attacks, Great White Shark, Species information (408 words)
The average lifespan is 20-25 years, but some, like the dogfish shark can live up to 100 years.
On of the misconceptions when dealing with sharks is that they have poor vision.
Sharks have relatively large brains, and can be compared to relatively advanced animals.
Shark :: Enterprise Community Platform (683 words)
Shark can be used by small and large businesses in a range of industries and will certainly increase popularity of community and revenue.
Shark is directed towards the building of multi functional business communities, and the platform was developed to be stable and secure.
Shark is equipped with a smart and multifunctional administrator's panel, which offers to manage a community doing simple operations.
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