The tiger shark (''Galeocerdo cuvier'') is a species of

requiem shark Requiem sharks are sharks of the family Carcharhinidae in the order Carcharhiniformes. They are migratory, live-bearing sharks of warm seas (sometimes of brackish or fresh water) and include such species as the tiger shark, bull shark, le ...

and the last extant member of the

family Family (from la, familia) is a group of people related either by consanguinity (by recognized birth) or affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its members and of society. Idea ...

Galeocerdonidae. It is a large macropredator, capable of attaining a length over . Populations are found in many

tropical The tropics are the regions of Earth surrounding the Equator. They are defined in latitude by the Tropic of Cancer in the Northern Hemisphere at N and the Tropic of Capricorn in the Southern Hemisphere at S. The tropics are also referred to ...

and

temperate In geography, the temperate climates of Earth occur in the middle latitudes (23.5° to 66.5° N/S of Equator), which span between the tropics and the polar regions of Earth. These zones generally have wider temperature ranges throughout ...

waters, especially around central

Pacific The Pacific Ocean is the largest and deepest of Earth's five oceanic divisions. It extends from the Arctic Ocean in the north to the Southern Ocean (or, depending on definition, to Antarctica) in the south, and is bounded by the contine ...

islands. Its name derives from the dark stripes down its body, which resemble a

tiger The tiger (''Panthera tigris'') is the largest living Felidae, cat species and a member of the genus ''Panthera''. It is most recognisable for its dark vertical stripes on orange fur with a white underside. An apex predator, it primarily pr ...

's pattern, but fade as the shark matures. The tiger shark is a solitary, mostly nocturnal hunter. It is notable for having the widest food spectrum of all sharks, with a range of prey that includes

crustacean Crustaceans (Crustacea, ) form a large, diverse arthropod taxon which includes such animals as decapoda, decapods, ostracoda, seed shrimp, branchiopoda, branchiopods, argulidae, fish lice, krill, remipedes, isopoda, isopods, barnacles, copepods, ...

fish Fish are Aquatic animal, aquatic, craniate, gill-bearing animals that lack Limb (anatomy), limbs with Digit (anatomy), digits. Included in this definition are the living hagfish, lampreys, and Chondrichthyes, cartilaginous and bony fish as we ...

seals Seals may refer to: * Pinniped, a diverse group of semi-aquatic marine mammals, many of which are commonly called seals, particularly: ** Earless seal, or "true seal" ** Fur seal * Seal (emblem), a device to impress an emblem, used as a means of a ...

bird Birds are a group of warm-blooded vertebrates constituting the class Aves (), characterised by feathers, toothless beaked jaws, the laying of hard-shelled eggs, a high metabolic rate, a four-chambered heart, and a strong yet lightweig ...

squid True squid are molluscs with an elongated soft body, large eyes, eight arms, and two tentacles in the superorder Decapodiformes, though many other molluscs within the broader Neocoleoidea are also called squid despite not strictly fittin ...

turtle Turtles are an order of reptiles known as Testudines, characterized by a special shell developed mainly from their ribs. Modern turtles are divided into two major groups, the Pleurodira (side necked turtles) and Cryptodira (hidden necked t ...

sea snake Sea snakes, or coral reef snakes, are elapid snakes that inhabit marine environments for most or all of their lives. They belong to two subfamilies, Hydrophiinae and Laticaudinae. Hydrophiinae also includes Australasian terrestrial snakes, w ...

dolphin A dolphin is an aquatic mammal within the infraorder Cetacea. Dolphin species belong to the families Delphinidae (the oceanic dolphins), Platanistidae (the Indian river dolphins), Iniidae (the New World river dolphins), Pontoporiidae (the b ...

s, and even other smaller sharks. It also has a reputation as a "garbage eater", consuming a variety of inedible, man-made objects that linger in its stomach. Though

apex predator An apex predator, also known as a top predator, is a predator at the top of a food chain, without natural predators of its own. Apex predators are usually defined in terms of trophic dynamics, meaning that they occupy the highest trophic lev ...

s, tiger sharks are sometimes taken as prey by groups of

killer whale The orca or killer whale (''Orcinus orca'') is a toothed whale belonging to the oceanic dolphin family, of which it is the largest member. It is the only extant species in the genus ''Orcinus'' and is recognizable by its black-and-white pat ...

s. It is considered a

near threatened species A near-threatened species is a species which has been categorized as "Near Threatened" (NT) by the International Union for Conservation of Nature as that may be vulnerable to endangerment in the near future, but it does not currently qualify fo ...

because of finning and fishing by humans. The tiger shark is second only to the

great white Great White is an American rock band formed in Los Angeles in 1977. The band peaked with several albums during the mid-to-late 1980s, including the platinum-selling records ''Once Bitten'' (1987) and '' ...Twice Shy'' (1989), and those albums ...

in recorded fatal attacks on humans, but these events are still exceedingly rare.

Taxonomy

The shark was first described by Peron and Lesueur in 1822, and was given the name ''Squalus cuvier''. Müller and

Henle Henle can refer to: *Friedrich Gustav Jakob Henle, a German physician, pathologist and anatomist (1809–1885) ** Loop of Henle In the kidney, the loop of Henle () (or Henle's loop, Henle loop, nephron loop or its Latin counterpart ''ansa nephroni ...

in 1837 renamed it ''Galeocerdo tigrinus''. The genus, ''Galeocerdo'', is derived from the Greek ''galeos'', which means shark, and ''kerdo'', the word for fox. It is often colloquially called the man-eater shark. The tiger shark is a member of the order

Carcharhiniformes Carcharhiniformes , the ground sharks, are the largest order of sharks, with over 270 species. They include a number of common types, such as catsharks, swellsharks, and the sandbar shark. Members of this order are characterized by the presenc ...

, the most species-rich order of sharks, with more than 270 species also including the small catsharks and

hammerhead shark The hammerhead sharks are a group of sharks that form the family Sphyrnidae, so named for the unusual and distinctive structure of their heads, which are flattened and laterally extended into a "hammer" shape called a cephalofoil. Most hammerhe ...

s. Members of this order are characterized by the presence of a

nictitating membrane The nictitating membrane (from Latin '' nictare'', to blink) is a transparent or translucent third eyelid present in some animals that can be drawn across the eye from the medial canthus to protect and moisten it while maintaining vision. All ...

over the eyes, two dorsal fins, an

anal fin Fins are distinctive anatomical features composed of bony spines or rays protruding from the body of a fish. They are covered with skin and joined together either in a webbed fashion, as seen in most bony fish, or similar to a flipper, as see ...

, and five

gill A gill () is a respiratory organ that many aquatic organisms use to extract dissolved oxygen from water and to excrete carbon dioxide. The gills of some species, such as hermit crabs, have adapted to allow respiration on land provided they ar ...

slits. It is the largest member of the order, commonly referred to as

s. This order consists of mostly slender but powerful mid- to large-sized sharks and includes some other well-known sharks, such as the

blue shark The blue shark (''Prionace glauca''), also known as the great blue shark, is a species of requiem shark, in the family Carcharhinidae, which inhabits deep waters in the world's temperate and tropical oceans. Averaging around and preferring ...

(''Prionace glauca''),

lemon shark The lemon shark (''Negaprion brevirostris'') is a species of shark from the family Carcharhinidae and is classified as a Vulnerable species by the International Union for the Conservation of Nature. Lemon sharks can grow to in length. They are ...

(''Negaprion brevirostris''), and bull shark (''Carcharhinus leucas'').

Description

The tiger shark commonly attains adult length of and weighs often around . It is dimorphic, with females being the larger sex. Mature females are often over while mature males rarely get that large.Meyer, C. G., O'Malley, J. M., Papastamatiou, Y. P., Dale, J. J., Hutchinson, M. R., Anderson, J. M., Royer, M. A. & Holland, K. N. (2014). ''Growth and maximum size of tiger sharks (Galeocerdo cuvier) in Hawaii''. PLoS One, 9(1), e84799. Exceptionally large females reportedly can measure over , and the largest males . Weights of particularly large female tiger sharks can exceed . One pregnant female caught off Australia reportedly measured long and weighed . Even larger unconfirmed catches have been claimed. Some papers have accepted a record of an exceptional length for a tiger shark, but since this is far larger than any scientifically observed specimen, verification would be needed. A 2019 study suggested that

Pliocene The Pliocene ( ; also Pleiocene) is the epoch in the geologic time scale that extends from 5.333 million to 2.58extant Extant is the opposite of the word extinct. It may refer to: * Extant hereditary titles * Extant literature, surviving literature, such as ''Beowulf'', the oldest extant manuscript written in English * Extant taxon, a taxon which is not extinct, ...

sharks, the tiger shark ranks in average size only behind the

whale shark The whale shark (''Rhincodon typus'') is a slow-moving, filter feeder, filter-feeding carpet shark and the largest known Extant taxon, extant fish species. The largest confirmed individual had a length of .McClain CR, Balk MA, Benfield MC, Bran ...

(''Rhincodon typus''), the basking shark (''Cetorhinus maximus''), and the

great white shark The great white shark (''Carcharodon carcharias''), also known as the white shark, white pointer, or simply great white, is a species of large mackerel shark which can be found in the coastal surface waters of all the major oceans. It is nota ...

(''Carcharodon carcharias''). This makes it the second-largest predatory shark, after the great white. Some other species such as

megamouth shark The megamouth shark (''Megachasma pelagios'') is a species of deepwater shark. It is rarely seen by humans and is the smallest of the three extant filter-feeding sharks alongside the relatively larger whale shark and basking shark. Since its d ...

s (''Megachasma pelagios''), Pacific sleeper sharks (''Somniosus pacificus''),

Greenland shark The Greenland shark (''Somniosus microcephalus''), also known as the gurry shark, grey shark, or by the Kalaallisut name ''eqalussuaq'', is a large shark of the family Somniosidae ("sleeper sharks"), closely related to the Pacific and souther ...

s (''Somniosus microcephalus''), and

bluntnose sixgill shark The bluntnose sixgill shark (''Hexanchus griseus''), often simply called the cow shark, is the largest hexanchoid shark, growing to in length. It is found in tropical and temperate waters worldwide and its diet is widely varied by region. The ...

s (''Hexanchus griseus'') broadly overlap in size with the tiger shark, but as these species are comparatively poorly studied, whether their typical mature size matches that of the tiger shark is unclear. The great hammerhead (''Sphyrna mokarran''), a member of the same taxonomic order as the tiger shark, has a similar or even greater average body length, but is lighter and less bulky, with a maximum known weight of . Tiger shark teeth are unique with very sharp, pronounced serrations and an unmistakable sideways-pointing tip. Such dentition has developed to slice through flesh, bone, and other tough substances such as turtle shells. Like most sharks, its teeth are continually replaced by rows of new teeth throughout the shark's life. Relative to the shark's size, tiger shark teeth are considerably shorter than those of a great white shark, but they are nearly as broad as the root as the great white's teeth and are arguably better suited to slicing through hard-surfaced prey.Randall, J. E. (1992). Review of the biology of the tiger shark (Galeocerdo cuvier). Marine and Freshwater Research, 43(1), 21–31. A tiger shark generally has long fins to provide lift as the shark maneuvers through water, while the long upper tail provides bursts of speed. The tiger shark normally swims using small body movements. Galeocerdo cuvier jaws.jpg, Jaws Galeocerdo cuvier jaws2.jpg, Jaws, wide open Galeocerdo cuvier upper teeth.jpg, Upper teeth Galeocerdo cuvier lower teeth.jpg, Lower teeth

Skin

The skin of a tiger shark can typically range from blue to light green with a white or light-yellow underbelly. The advantage of this is that when it is hunting for its prey, when prey looks at the shark from above, the shark will be camouflaged, since the water below is darker. When prey is below the shark and looks up the light underbelly will also camouflage the shark with the sunlight. This is known as

countershading Countershading, or Thayer's law, is a method of camouflage in which an animal's coloration is darker on the top or upper side and lighter on the underside of the body. This pattern is found in many species of mammals, reptiles, birds, fish ...

. Dark spots and stripes are most visible in young sharks and fade as the shark matures. Its head is somewhat wedge-shaped, which makes it easy to turn quickly to one side. They have small pits on the snout which hold electroreceptors called the

ampullae of Lorenzini Ampullae of Lorenzini (singular ''Ampulla'') are electroreceptors, sense organs able to detect electric fields. They form a network of mucus-filled pores in the skin of cartilaginous fish (sharks, rays, and chimaeras) and of basal actinopterygi ...

, which enable them to detect electric fields, including the weak electrical impulses generated by prey, which helps them to hunt. Tiger sharks also have a sensory organ called a

lateral line The lateral line, also called the lateral line organ (LLO), is a system of sensory organs found in fish, used to detect movement, vibration, and pressure gradients in the surrounding water. The sensory ability is achieved via modified epithelial ...

which extends on their flanks down most of the length of their sides. The primary role of this structure is to detect minute vibrations in the water. These adaptations allow the tiger shark to hunt in darkness and detect hidden prey.

Vision

Sharks do not have moveable upper or lower eyelids, but the tiger shark—among other sharks—has a

, a clear eyelid that can cover the eye. A reflective layer behind the tiger shark's

retina The retina (from la, rete "net") is the innermost, light-sensitive layer of tissue of the eye of most vertebrates and some molluscs. The optics of the eye create a focused two-dimensional image of the visual world on the retina, which the ...

, called the

tapetum lucidum The ''tapetum lucidum'' ( ; ; ) is a layer of tissue in the eye of many vertebrates and some other animals. Lying immediately behind the retina, it is a retroreflector. It reflects visible light back through the retina, increasing the light a ...

, allows light-sensing cells a second chance to capture

photon A photon () is an elementary particle that is a quantum of the electromagnetic field, including electromagnetic radiation such as light and radio waves, and the force carrier for the electromagnetic force. Photons are massless, so they alwa ...

s of visible light. This enhances vision in low-light conditions.

Distribution and habitat

The tiger shark is often found close to the coast, mainly in

and

subtropical The subtropical zones or subtropics are geographical and climate zones to the north and south of the tropics. Geographically part of the temperate zones of both hemispheres, they cover the middle latitudes from to approximately 35° north a ...

waters throughout the world. Its behavior is primarily

nomadic A nomad is a member of a community without fixed habitation who regularly moves to and from the same areas. Such groups include hunter-gatherers, pastoral nomads (owning livestock), tinkers and trader nomads. In the twentieth century, the popu ...

, but is guided by warmer currents, and it stays closer to the equator throughout the colder months. It tends to stay in deep waters that line reefs, but it does move into channels to pursue prey in shallower waters. In the western

Pacific Ocean The Pacific Ocean is the largest and deepest of Earth's five oceanic divisions. It extends from the Arctic Ocean in the north to the Southern Ocean (or, depending on definition, to Antarctica) in the south, and is bounded by the conti ...

, the shark has been found as far north as

Japan Japan ( ja, 日本, or , and formally , ''Nihonkoku'') is an island country in East Asia. It is situated in the northwest Pacific Ocean, and is bordered on the west by the Sea of Japan, while extending from the Sea of Okhotsk in the n ...

and as far south as

New Zealand New Zealand ( mi, Aotearoa ) is an island country in the southwestern Pacific Ocean. It consists of two main landmasses—the North Island () and the South Island ()—and over 700 smaller islands. It is the sixth-largest island coun ...

. It has also been recorded in the

Mediterranean Sea The Mediterranean Sea is a sea connected to the Atlantic Ocean, surrounded by the Mediterranean Basin and almost completely enclosed by land: on the north by Western and Southern Europe and Anatolia, on the south by North Africa, and on ...

, but rarely, off Malaga (Spain), Sicily (Italy) and Libya.Atlas of Exotic Fishes in the Mediterranean Sea (Galeocerdo cuvier). 2nd Edition. 2021. 366p. CIESM Publishers, Paris, Monaco.https://ciesm.org/atlas/fishes_2nd_edition/Galeocerdo_cuvier.pdf Tiger sharks can be seen in the

Gulf of Mexico The Gulf of Mexico ( es, Golfo de México) is an ocean basin and a marginal sea of the Atlantic Ocean, largely surrounded by the North American continent. It is bounded on the northeast, north and northwest by the Gulf Coast of the United ...

, North American beaches, and parts of South America. It is also commonly observed in the

Caribbean Sea The Caribbean Sea ( es, Mar Caribe; french: Mer des Caraïbes; ht, Lanmè Karayib; jam, Kiaribiyan Sii; nl, Caraïbische Zee; pap, Laman Karibe) is a sea of the Atlantic Ocean in the tropics of the Western Hemisphere. It is bounded by Mexic ...

. Other locations where tiger sharks are seen include off Africa, China,

India India, officially the Republic of India (Hindi: ), is a country in South Asia. It is the List of countries and dependencies by area, seventh-largest country by area, the List of countries and dependencies by population, second-most populous ...

Australia Australia, officially the Commonwealth of Australia, is a sovereign country comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands. With an area of , Australia is the largest country by ...

, and

Indonesia Indonesia, officially the Republic of Indonesia, is a country in Southeast Asia and Oceania between the Indian and Pacific oceans. It consists of over 17,000 islands, including Sumatra, Java, Sulawesi, and parts of Borneo and New Gui ...

. Certain tiger sharks have been recorded at depths just shy of .

Feeding

The tiger shark is an

and has a reputation for eating almost anything. These predators swim close inland to eat at night, and during the day swim out into deeper waters. Young tiger sharks are found to feed largely on small fish, as well as various small

jellyfish Jellyfish and sea jellies are the informal common names given to the medusa-phase of certain gelatinous members of the subphylum Medusozoa, a major part of the phylum Cnidaria. Jellyfish are mainly free-swimming marine animals with umbre ...

, and

mollusk Mollusca is the second-largest phylum of invertebrate animals after the Arthropoda, the members of which are known as molluscs or mollusks (). Around 85,000 extant species of molluscs are recognized. The number of fossil species is e ...

s including

cephalopod A cephalopod is any member of the molluscan class Cephalopoda ( Greek plural , ; "head-feet") such as a squid, octopus, cuttlefish, or nautilus. These exclusively marine animals are characterized by bilateral body symmetry, a prominent head ...

s. Around the time they attain , or near sexual maturity, their selection expands considerably, and much larger animals become regular prey. Numerous

s, sea birds,

marine mammal Marine mammals are aquatic mammals that rely on the ocean and other marine ecosystems for their existence. They include animals such as seals, whales, manatees, sea otters and polar bears. They are an informal group, unified only by their ...

s (e.g.

bottlenose dolphin Bottlenose dolphins are aquatic mammals in the genus ''Tursiops.'' They are common, cosmopolitan members of the family Delphinidae, the family of oceanic dolphins. Molecular studies show the genus definitively contains two species: the comm ...

s (''Tursiops''),

common dolphin The common dolphin (''Delphinus delphis'') is the most abundant cetacean in the world, with a global population of about six million. Despite this fact and its vernacular name, the common dolphin is not thought of as the archetypal dolphin, wi ...

s (''Delphinus''),

spotted dolphin Spotted dolphin refers to either one of two closely related dolphin species, being: * Atlantic spotted dolphin, ''Stenella frontalis'' * pantropical spotted dolphin, ''Stenella attenuata'' While the pantropical spotted dolphin can be found aroun ...

s (''Stenella''),

dugong The dugong (; ''Dugong dugon'') is a marine mammal. It is one of four living species of the order Sirenia, which also includes three species of manatees. It is the only living representative of the once-diverse family Dugongidae; its closest m ...

s (''Dugong dugon''),

seal Seal may refer to any of the following: Common uses * Pinniped, a diverse group of semi-aquatic marine mammals, many of which are commonly called seals, particularly: ** Earless seal, or "true seal" ** Fur seal * Seal (emblem), a device to imp ...

s and

sea lion Sea lions are pinnipeds characterized by external ear flaps, long foreflippers, the ability to walk on all fours, short and thick hair, and a big chest and belly. Together with the fur seals, they make up the family Otariidae, eared seals. ...

s, and

sea turtle Sea turtles (superfamily Chelonioidea), sometimes called marine turtles, are reptiles of the order Testudines and of the suborder Cryptodira. The seven existing species of sea turtles are the flatback, green, hawksbill, leatherback, loggerhe ...

s (including the three largest species: the leatherback (''Dermochelys coriacea''), the

loggerhead Loggerhead or Loggerheads may refer to: Places * Loggerheads, Denbighshire, a village in Denbighshire, Wales * Loggerheads, Staffordshire, a small village in north Staffordshire, England * Loggerhead Key, the largest islet in the Dry Tortugas, F ...

(''Caretta caretta'') and the

green sea turtle The green sea turtle (''Chelonia mydas''), also known as the green turtle, black (sea) turtle or Pacific green turtle, is a species of large sea turtle of the family Cheloniidae. It is the only species in the genus ''Chelonia''. Its range exten ...

s (''Chelonia mydas''),) are regularly eaten by adult tiger sharks. In fact, adult sea turtles have been found in up to 20.8% of studied tiger shark stomachs, indicating somewhat of a dietary preference for sea turtles where they are commonly encountered. They also eat other sharks (including adult

sandbar shark The sandbar shark (''Carcharhinus plumbeus'') also known as the brown shark or thickskin shark, is a species of requiem shark, and part of the family Carcharhinidae, native to the Atlantic Ocean and the Indo-Pacific. It is distinguishable by it ...

s (''Carcharhinus plumbeus'')), as well as

ray Ray may refer to: Fish * Ray (fish), any cartilaginous fish of the superorder Batoidea * Ray (fish fin anatomy), a bony or horny spine on a fin Science and mathematics * Ray (geometry), half of a line proceeding from an initial point * Ray (gr ...

s, and sometimes even other tiger sharks. Due to high risk of predation, dolphins often avoid regions inhabited by tiger sharks. Injured or ailing

whale Whales are a widely distributed and diverse group of fully aquatic placental marine mammals. As an informal and colloquial grouping, they correspond to large members of the infraorder Cetacea, i.e. all cetaceans apart from dolphins and ...

s may also be attacked and eaten. A group was documented killing an ailing

humpback whale The humpback whale (''Megaptera novaeangliae'') is a species of baleen whale. It is a rorqual (a member of the family Balaenopteridae) and is the only species in the genus ''Megaptera''. Adults range in length from and weigh up to . The hu ...

(''Megaptera novaeangliae'') in 2006 near Hawaii. A scavenger, the tiger shark will feed on dead whales, and has been documented doing so alongside great white sharks. Evidence of

predation was identified in one study that found dugong tissue in 15 of 85 tiger sharks caught off the Australian coast. Additionally, examination of adult dugongs has shown scars from failed shark attacks. To minimize attacks, dugong microhabitats shift similarly to those of known tiger shark prey when the sharks are abundant. The broad, heavily calcified jaws and nearly terminal mouth, combined with robust, serrated teeth, enable the tiger shark to take on these large prey. In addition, excellent

eyesight Visual perception is the ability to interpret the surrounding environment through photopic vision (daytime vision), color vision, scotopic vision (night vision), and mesopic vision (twilight vision), using light in the visible spectrum reflect ...

and acute

sense of smell The sense of smell, or olfaction, is the special sense through which smells (or odors) are perceived. The sense of smell has many functions, including detecting desirable foods, hazards, and pheromones, and plays a role in taste. In humans, ...

enable it to react to faint traces of blood and follow them to the source. The ability to pick up low-frequency pressure waves enables the shark to advance towards an animal with confidence, even in murky water. The shark circles its prey and studies it by prodding it with its snout. When attacking, the shark often eats its prey whole, although larger prey are often eaten in gradual large bites and finished over time. Notably, terrestrial mammals, including

horse The horse (''Equus ferus caballus'') is a domesticated, one-toed, hoofed mammal. It belongs to the taxonomic family Equidae and is one of two extant subspecies of ''Equus ferus''. The horse has evolved over the past 45 to 55 million yea ...

s (''Equus ferus caballus''),

goat The goat or domestic goat (''Capra hircus'') is a domesticated species of goat-antelope typically kept as livestock. It was domesticated from the wild goat (''C. aegagrus'') of Southwest Asia and Eastern Europe. The goat is a member of the a ...

s (''Capra aegagrus hircus''),

sheep Sheep or domestic sheep (''Ovis aries'') are domesticated, ruminant mammals typically kept as livestock. Although the term ''sheep'' can apply to other species in the genus '' Ovis'', in everyday usage it almost always refers to domesticate ...

(''Ovis aries''), dogs (''Canis lupus familiaris''),

cat The cat (''Felis catus'') is a domestic species of small carnivorous mammal. It is the only domesticated species in the family Felidae and is commonly referred to as the domestic cat or house cat to distinguish it from the wild members of ...

s (''Felis catus''), and

brown rat The brown rat (''Rattus norvegicus''), also known as the common rat, street rat, sewer rat, wharf rat, Hanover rat, Norway rat, Norwegian rat and Parisian rat, is a widespread species of common rat. One of the largest muroids, it is a brown o ...

s (''Rattus norvegicus''), are fairly common in the stomach contents of tiger sharks around the coasts of Hawaii. In one case, remains of two flying foxes were found in the stomach of this shark. Because of its aggressive and indiscriminate feeding style, it often mistakenly eats inedible objects, such as automobile license plates,

oil An oil is any nonpolar chemical substance that is composed primarily of hydrocarbons and is hydrophobic (does not mix with water) & lipophilic (mixes with other oils). Oils are usually flammable and surface active. Most oils are unsaturated ...

cans,

tire A tire (American English) or tyre (British English) is a ring-shaped component that surrounds a Rim (wheel), wheel's rim to transfer a vehicle's load from the axle through the wheel to the ground and to provide Traction (engineering), t ...

s, and

baseballs A baseball is a ball used in the sport of the same name. The ball consists of a rubber or cork center wrapped in yarn and covered with white natural horsehide or cowhide, or a synthetic composite leather. A regulation baseball is 9 to 9¼ inche ...

Predation by killer whales

Although tiger sharks are apex predators, they are sometimes preyed on by pods of

s. A pod's method of hunting a tiger shark is to drive it to the surface. A killer whale will then grab the shark mid-body and hold it upside down to induce

tonic immobility Apparent death, colloquially known as playing dead, feigning death, or playing possum, is a behavior in which animals take on the appearance of being dead. It is an immobile state most often triggered by a predatory attack and can be found in a ...

and drown the shark. The killer whales bite off the shark's fins before disemboweling and devouring it midwater.

Swimming efficiency and stealth

All tiger sharks generally swim slowly, which, combined with cryptic coloration, may make them difficult for prey to detect in some habitats. They are especially well camouflaged against dark backgrounds. Despite their sluggish appearance, tiger sharks are one of the strongest swimmers of the carcharhinid sharks. Once the shark has come close, a speed burst allows it to reach the intended prey before it can escape.

Reproduction

Males reach sexual maturity at and females at . Typical weight of relatively young sexually mature specimens, which often locally comprise the majority of tiger sharks encountered per game-fishing and scientific studies, is around . Females mate once every three years. They breed by internal fertilization. The male inserts one of his

clasper In biology, a clasper is a male anatomical structure found in some groups of animals, used in mating. Male cartilaginous fish have claspers formed from the posterior portion of their pelvic fin which serve to channel semen into the female's c ...

s into the female's genital opening (

cloaca In animal anatomy, a cloaca ( ), plural cloacae ( or ), is the posterior orifice that serves as the only opening for the digestive, reproductive, and urinary tracts (if present) of many vertebrate animals. All amphibians, reptiles and birds, ...

), acting as a guide for the

sperm Sperm is the male reproductive cell, or gamete, in anisogamous forms of sexual reproduction (forms in which there is a larger, female reproductive cell and a smaller, male one). Animals produce motile sperm with a tail known as a flagellum, ...

. The male uses his teeth to hold the female still during the procedure, often causing the female considerable discomfort. Mating in the Northern Hemisphere generally takes place between March and May, with birth between April and June the following year. In the Southern Hemisphere, mating takes place in November, December, or early January. The tiger shark is the only species in its family that is ovoviviparous; its eggs hatch internally and the young are born live when fully developed. Tiger Sharks are unique among all sharks in the fact that they employ embrytrophy to nourish their young inside the womb. The young gestate in sacks which are filled with a fluid that nourishes them. This allows for the young to dramatically increase in size, even though they have no placental connection to the mother. The young develop inside the mother's body up to 16 months. Litters range from 10 to 80 pups. A newborn is generally long. How long tiger sharks live is unknown, but they can live longer than 12 years.

Ontogeny

Tiger shark ontogeny has been little studied until recently, but studies by Hammerschlag ''et al.'', indicated that as they grow, their tails become more symmetrical with age. Additionally, while the heads on juvenile tiger sharks are more conical and similar to other requiem sharks, adult tiger sharks have a head which is relatively broader. The reason for the larger caudal fin on juvenile tiger sharks is theorized to be an adaptation to escape predation by larger predators and to catch quicker-moving prey. As tiger sharks mature, their head also becomes much wider and their tails no longer become as large in proportion to their body size as when they are juveniles because they do not face elevated levels of predation risk upon maturity. The results of this study were interpreted as reflecting two ecological transitions: as tiger sharks mature they become more migratory and having a symmetrical tail is more advantageous in long-distance traveling, and that tiger sharks consume more diverse prey items with age, which requires a greater bite force and broader head.

Conservation

The tiger shark is captured and killed for its

fins A fin is a thin component or appendage attached to a larger body or structure. Fins typically function as foils that produce lift or thrust, or provide the ability to steer or stabilize motion while traveling in water, air, or other fluids. Fin ...

flesh Flesh is any aggregation of soft tissues of an organism. Various multicellular organisms have soft tissues that may be called "flesh". In mammals, including humans, ''flesh'' encompasses muscles, fats and other loose connective tissues, but ...

, and

liver The liver is a major organ only found in vertebrates which performs many essential biological functions such as detoxification of the organism, and the synthesis of proteins and biochemicals necessary for digestion and growth. In humans, it i ...

. It is caught regularly in target and nontarget fisheries. Several populations have declined where they have been heavily fished. Continued demand for fins may result in further declines. They are considered a

due to excessive finning and fishing by humans according to

International Union for Conservation of Nature The International Union for Conservation of Nature (IUCN; officially International Union for Conservation of Nature and Natural Resources) is an international organization working in the field of nature conservation and sustainable use of natu ...

. In June 2018 the New Zealand

Department of Conservation An environmental ministry is a national or subnational government agency politically responsible for the environment and/or natural resources. Various other names are commonly used to identify such agencies, such as Ministry of the Environment ...

classified the tiger shark as "Migrant" with the qualifier "Secure Overseas" under the

New Zealand Threat Classification System The New Zealand Threat Classification System is used by the Department of Conservation to assess conservation priorities of species in New Zealand. The system was developed because the IUCN Red List, a similar conservation status system, had some ...

. While shark fin has very few nutrients, shark liver has a high concentration of

vitamin A Vitamin A is a fat-soluble vitamin and an essential nutrient for humans. It is a group of organic compounds that includes retinol, retinal (also known as retinaldehyde), retinoic acid, and several provitamin A carotenoids (most notably ...

, which is used in the production of vitamin oils. In addition, the tiger shark is captured and killed for its distinct skin, as well as by big-game fishers. In 2010, Greenpeace International added the tiger shark to its seafood red list, which is a list of commonly sold fish likely to come from unsustainable fisheries.

Relationship with humans

Although sharks rarely bite humans, the tiger shark is reported to be responsible for a large share of fatal shark-bite incidents, and is regarded as one of the most dangerous shark species. They often visit shallow reefs, harbors, and canals, creating the potential for encounter with humans. The tiger shark also dwells in river mouths and other runoff-rich water. While it ranks second on the list of number of recorded shark attacks on humans, behind only the great white shark, such attacks are few and very seldom fatal. Typically, three to four shark bites occur per year in Hawaii; one notable survivor of such an attack is

surfing Surfing is a surface water sport in which an individual, a surfer (or two in tandem surfing), uses a board to ride on the forward section, or face, of a moving wave of water, which usually carries the surfer towards the shore. Waves suitable ...

champion

Bethany Hamilton Bethany Meilani Hamilton (born February 8, 1990) is an American professional surfer and writer who survived a 2003 shark attack in which her left arm was bitten off and who ultimately returned to professional surfing. She wrote about her exper ...

, who lost her left arm at age 13 to a tiger shark in 2003. This bite rate is very low, considering that thousands of people swim, surf, and dive in Hawaiian waters every day. Human interactions with tiger sharks in Hawaiian waters have been shown to increase between September and November, when tiger shark females are believed to migrate to the islands to give birth. Between 1959 and 2000, 4,668 tiger sharks were

culled In biology, culling is the process of segregating organisms from a group according to desired or undesired characteristics. In animal breeding, it is the process of removing or segregating animals from a breeding stock based on a specific tr ...

in an effort to protect the

tourism Tourism is travel for pleasure or business; also the theory and practice of touring (disambiguation), touring, the business of attracting, accommodating, and entertaining tourists, and the business of operating tour (disambiguation), tours. Th ...

industry. Despite damaging the shark population, these efforts were shown to be ineffective in decreasing the number of interactions between humans and tiger sharks. Feeding sharks in Hawaii (except for traditional Hawaiian cultural or religious practices) is illegal, and interaction with them, such as cage diving, is discouraged. South African shark behaviorist and shark diver Mark Addison demonstrated divers could interact and dive with them outside of a shark cage in a 2007

Discovery Channel Discovery Channel (known as The Discovery Channel from 1985 to 1995, and often referred to as simply Discovery) is an American cable channel owned by Warner Bros. Discovery, a publicly traded company run by CEO David Zaslav. , Discovery Chan ...

special, and underwater photographer Fiona Ayerst swam with them in

the Bahamas The Bahamas (), officially the Commonwealth of The Bahamas, is an island country within the Lucayan Archipelago of the West Indies in the North Atlantic. It takes up 97% of the Lucayan Archipelago's land area and is home to 88% of the a ...

. At "Tiger Beach" off Grand Bahama, uncaged diving with – and even the handling of – female tiger sharks has become a routine occurrence.

Mythology

Tiger sharks are considered to be sacred '' aumākua'' (ancestor spirits) by some

native Hawaiians Native Hawaiians (also known as Indigenous Hawaiians, Kānaka Maoli, Aboriginal Hawaiians, First Hawaiians, or simply Hawaiians) ( haw, kānaka, , , and ), are the indigenous ethnic group of Polynesian people of the Hawaiian Islands. Hawa ...

References

External links

*
General information
Enchanted Learning. Retrieved January 22, 2005.

Shark Info. Retrieved January 22, 2005.

Research program. Retrieved January 22, 2005.

from

National Geographic ''National Geographic'' (formerly the ''National Geographic Magazine'', sometimes branded as NAT GEO) is a popular American monthly magazine published by National Geographic Partners. Known for its photojournalism, it is one of the most widel ...

Tracking research on tiger sharks

*
Diver Has Been Friends With Tiger Shark For 20 Years!
{{Authority control tiger shark Pantropical fish Extant Ypresian first appearances Ovoviviparous fish Near threatened fauna of North America tiger shark tiger shark tiger shark Articles containing video clips Apex predators

Taxonomy

Description

Skin

Vision

Distribution and habitat

Feeding

Predation by killer whales

Swimming efficiency and stealth

Reproduction

Ontogeny

Conservation

Relationship with humans

Mythology

See also

References

External links