The tiger shark ( Galeocerdo cuvier ) is a requiem shark species and the only remaining genus member Galeocerdo . It is a large makropredator, capable of reaching lengths above 5 m (16 ft 5 inches). The population is found in many tropical and subtropical waters, especially around the central Pacific islands. Its name comes from the dark lines under its body, which resembles the pattern of the tiger but fades when the shark matures.
Tiger sharks are solitary hunters, mostly nocturnal. It is important to have the widest food spectrum of all sharks, with a variety of prey that includes crustaceans, fish, seals, birds, squid, turtles, sea snakes, dolphins, and even other small sharks. He also has a reputation as a "garbage eater", consuming a variety of non-edible man-made objects left in his stomach. Despite the top predators, tiger sharks are sometimes taken by a group of killer whales. This is considered a species that is almost threatened due to human catch and fishing.
Tiger sharks are the second after a large white record of fatal attacks on humans.
Video Tiger shark
Taxonomy
The shark was first described by Peron and Lesueur in 1822, and is named Squalus cuvier . MÃÆ'¼ller and Henle in 1837 renamed it Galeocerdo tigrinus . The genus, Galeocerdo , is derived from the Greek galeos , which means shark, and kerdo , the word for fox. Often colloquially called a human-eating shark.
Tiger sharks are members of the Carcharhiniformes order, the species richest shark, with more than 270 species also including small sharks and hammerhead sharks. Members of this order are characterized by a nictitating membrane over the eye, two dorsal fins, an anal fin, and five gill slits. It is the largest member of the Carcharhinidae family, commonly referred to as the requiem shark. The family consists of moderate to powerful sharks and includes other famous sharks, such as the blue shark ( Prionace glauca ), lemon shark ( Negaprion brevirostris ), and the bull shark ( Carcharhinus leucas ).
Maps Tiger shark
Description
Tiger sharks typically reach a length of 3.25-4.25 m (10Ã, ft 8Ã.-13Ã, ft 11Ã, in) and weigh about 385-635 kg (849-1,400 pounds). It's dimorphic, with very large women reported to be over 5 m (16 ft. 5 in), and the largest man of 4 m (13 ft. 1 in). The weight of a very large female tiger shark can reach and exceed 900 kg (2,000 pounds). One pregnant woman caught in Australia reportedly measured a length of 5.5 m (18 feet 1 inch) and weighed 1,524 kg (3,360 pounds). Even larger, unconfirmed catches have been claimed. Some papers have received a remarkable 7.4 m (24 m3 in) long note for tiger sharks, but since this is much larger than the specimens observed scientifically, verification will be required.
Among the largest remaining sharks, tiger sharks are ranked only behind the whale shark ( Rhincodon typus ), the sun shark ( Cetorhinus maximus ), and the large white shark ( Carcharodon carcharias ). Some other species such as Megamouth sharks (Megawas pelagios sharks), Pacific bed sharks (Somniosus pacificus ), Greenland sharks (Somniosus microcephalus ), and blunt sharks sixgill ( Hexanchus griseus ) generally overlaps in size with tiger sharks, but because these species are relatively less studied, it is unclear whether their average adult size matches tiger sharks. The big hammer (Sphyrna mokarran ), member of the same taxonomic order as the tiger shark, has the same or even greater average body length, but is lighter and less massive, with the maximum weight known from 580 kg (1,280 pounds).
Tiger shark teeth have their own uniqueness with very sharp teeth, clear and pointed ends that are not wrong. Such tooth growth has evolved to cut meat, bones, and other hard substances such as turtle shells. Like most sharks, their teeth are constantly being replaced by new rows of teeth throughout the life of sharks. Due to the size of sharks, tiger shark teeth are much shorter than those of large white sharks, but they are almost as large as large white teeth and arguably more suitable for cutting through hard-eyed prey.
A shark tiger generally has a long fins to provide lifting power such as shark maneuvers through water, while the long upper tail provides bursts of speed. Tiger sharks usually swim using small body movements. The dorsal fin and the high dorsal fin act as a pivot, allowing it to spin rapidly on its axis, although the shark's dorsal fin is typically close to its tail.
Skin
Tiger shark skin can usually range from blue to light green with a bright white or yellow stomach. The advantage of this is when hunting for its prey, when the prey sees the shark from above, the shark will be disguised as the water below darker. And when the prey is under the shark and looks up, of course because the sun, lighter so the lighter belly will also disguise the shark. This is known as countershading. Black spots and lines are most visible on young sharks and fade as the shark matures. His head is somewhat wedge-shaped, which makes it easy to turn quickly to one side. They have a small hole in the muzzle that holds electroreceptors called ampullae from Lorenzini, allowing them to detect electric fields, including weak electrical impulses generated by prey, which helps them to hunt. Tiger sharks also have sensory organs called rib lines that stretch across the undersides of most of their sides. The main role of this structure is to detect minute vibrations in the water. This adaptation allows tiger sharks to hunt in the dark and detect hidden prey.
Vision
Sharks do not have an up or down moving eyelid, but tiger sharks - among other sharks - have nictitating membranes, clear eyelids that cover the eyes. The reflective layer behind the tiger shark's retina, called tapetum lucidum, allows the cells of second-sense light sensing to capture visible light photons. It improves eyesight in low light conditions.
Distribution and habitat
Tiger sharks are often found near the coast, especially in tropical and subtropical waters around the world. His behavior is mainly nomadic, but guided by a warmer current, and remains closer to the equator during the cold months. It tends to stay in the inner waters that line the rock, but it moves to the channel to catch prey in the shallower waters. In the western Pacific Ocean, sharks have been found to the north as far as Japan and as far south as New Zealand. A tiger shark marked in the Caribbean has been tracked migrating to Cape Cod; although they are a tropical species, the warm Gulf Stream brings the Cape Cod coast into the extreme northern regions during the summer. It has also been recorded in the Mediterranean but so far only on two occasions, first from Spain and then from Sicily.
Tiger sharks can be seen in the Gulf of Mexico, the coast of North America, and parts of South America. This is also commonly observed in the Caribbean Sea. Other locations where tiger sharks are seen include Africa, China, Hong Kong, India, Australia and Indonesia.
Certain tiger sharks have been recorded at a depth of only as high as 900 m (3,000 ft), but some sources claim they are moving into shallow waters that are usually considered too shallow for species of its size. A recent study showed that average tiger sharks would be recorded at 350 m (1,100 ft), so it is not uncommon to see tiger sharks in shallow waters. However, tiger sharks in Hawaii have been observed at shallow depths of 10.0 ft (3.05 m) and are regularly observed in coastal waters at depths of 6 to 12 m (20 to 40 feet).
Giving Feeding
Tiger sharks are the top predators and have a reputation for eating anything. These predators swim near the mainland to eat at night, and during the day swim to deeper waters. Young tiger sharks are found to feed most small fish, as well as various small jellyfish, and mollusks including cephalopods. Around the time they reach 2.3 m (7.5 ft), or close to sexual maturity, their selection grows rapidly, and much larger animals become common prey. Many fish, crustaceans, seabirds, sea snakes, marine mammals (eg bottlenose dolphins ( Tursiops ), ordinary dolphins ( Delphinus ), leopard dolphins ( Stenella i), dugong (dugong dugon), seals and sea lions, and sea turtles (including the three largest species: leatherback turtle Dermochelys coriacea ), crock ( Caretta caretta ) and green turtle ( Chelonia mydas ),) are regularly eaten by adult tiger sharks. - adult turtles have been found up to 20.8% of studying the shark tiger's belly, showing little of the food preferences for turtles where they are commonly encountered, they also eat other sharks (including adult sandbar sharks ( Carcharhinus plumbeus ) ), also rays, and sometimes even other tiger sharks.
Due to the high risk of predation, dolphins often avoid areas inhabited by tiger sharks. Wounded or sick whales can also be attacked and eaten. A documented group killed a sick humpback whale ( Megaptera novaeangliae ) in 2006 near Hawaii. A scavenger, a tiger shark will eat a dead whale, and has been documented doing it along with a great white man.
Evidence of predation mermaids was identified in a study that found dugong tissue in 15 of 85 tiger sharks captured off the coast of Australia. In addition, adult mermaid checks have shown scars from failed shark attacks. To minimize the attacks, dugong microhabitats shifted similar to those known to tiger sharks when sharks abound.
The broad and highly calcified jaw and almost terminal mouth, combined with strong jagged teeth, allow tiger sharks to pick up these large prey. In addition, excellent vision and acute sense of smell make it able to react to the blood trail and follow them to the source. The ability to take low-frequency pressure waves allows sharks to progress toward animals with confidence, even in cloudy waters. The shark surrounds its prey and learns it by pushing it with its muzzle. When attacked, sharks often eat their prey intact, although larger prey is often eaten in large bites gradually and finished over time.
In particular, terrestrial mammals, including horses (Equus ferus caballus), goats (Capra aegagrus hircus ), sheep ( Ovis aries ), dogs (< iis Canis lupus familiaris ), cat ( Felis catus ), and brown mice (Rattus norvegicus ), are quite common in hull tiger shark contents around the coast Hawaii. In one case, the remaining two flying foxes were found in the belly of this shark. Because of its aggressive and indiscriminate style of eating, it often misrepresents ineffable objects, such as license plates, oil cans, tires, and underground balls.
Efficiency and stealth pool
All tiger sharks generally swim slowly, combined with vague coloring, can make them difficult prey to be detected in some habitats. They are especially well-disguised against a dark background. Despite their sluggish appearance, the tiger shark is one of the strongest swimmers of the carcharhinid shark. Once the shark approaches, the bursts of speed allow it to reach the desired prey before it can escape.
Reproduction
Men achieve sexual maturity at 2.3-2.9 m (7.5-9.5 m) and women in 2.5- 3.5 m (8.2-11.5 ft). The average weight of relatively young adult sex specimens, often locally made up of the majority of tiger sharks encountered per game-fishing and scientific research, is about 80-130 kg (180 to 290 pounds). Females mate every three years. They breed with internal fertilization. Men enter one of the claspers into the female genital opening (cloaca), acting as a guide for sperm. Men use their teeth to hold women during the procedure, often causing female discomfort. Married in the Northern Hemisphere generally occurs between March and May, with births between April and June of the following year. In the southern hemisphere, mating occurs in November, December, or early January. The tiger shark is the only species in its ovoviviparous family; the eggs hatch internally and the young are born alive when fully developed.
The young develop in the mother's body up to 16 months. Potatoes ranging from 10 to 80 children. Newborns generally have a length of 51 to 76 cm (20 to 30 inches). How long tiger sharks live is unknown, but they can live longer than 12 years.
Preservation
Tiger sharks were caught and killed for fins, flesh, and liver. He is regularly arrested in targets and not fisheries targets. Some of the population has declined where they have been fishing a lot. Continuous demand for fins may lead to further decline in the future. They are regarded as a near threatened species due to excessive fishing and fishing by humans according to the International Union for Conservation of Nature.
While shark fins have very little nutrition, shark liver has a high concentration of vitamin A used in the production of vitamin oil. In addition, tiger sharks were caught and killed for their different skins, as well as by large fishermen.
In 2010, Greenpeace International added tiger sharks to its red list of seafood, which is a list of commonly sold fish worldwide, and which has a very high risk of sourced unsustainable fisheries.
Relationships with humans
Although sharks rarely bite humans, tiger sharks are reportedly responsible for most of the deadly shark bite incidents, and are sometimes considered to be one of the most dangerous shark species. They often visit shallow reefs, harbors, and canals, creating the potential to meet human beings. Tiger sharks also live in river estuaries and other runoff water. While tiger sharks are considered one of the most dangerous sharks for humans, the bite rate is low. This is the second in the list of the number of recorded bites in humans, with the great white shark being the first. On average, three to four shark bites occur annually in Hawaii, but they are rarely fatal; one person who survived such an attack was surfing champion Bethany Hamilton, who lost her left arm to a tiger shark in 2003. The bite level is very low considering thousands of people swim, surf, and dive in Hawaiian waters every day. Human interaction with tiger sharks in Hawaiian waters has been shown to increase between September and November, when tiger female sharks are believed to migrate to the islands for childbirth.
Between 1959 and 2000, 4,668 tiger sharks were destroyed in an attempt to protect the tourism industry. This effort, despite the deterioration of shark populations, proved ineffective in reducing the amount of interaction between humans and tiger sharks. Shark feeding in Hawaii (except for traditional Hawaiian cultural or religious practices) is illegal, and interaction with them, such as cage diving, is not recommended. Shark behavioral and shark divers from South Africa Mark Addison shows divers can interact and dive with them outside the shark cage in the special Discovery 2007 Channel, and underwater photographer Fiona Ayerst swims with them in the Bahamas. On the "Tiger Beach" of the Grand Bahama, diving without ropes with - and even handling - the female tiger shark has become a routine occurrence.
Mythology
Tiger shark is considered sacred na ? aumakua (ancestral spirits) by some native Hawaiians who think their eyeballs have special powers of visual perception. This is in line with the general facts about sharks and their highly developed senses.
See also
- List of sharks
- List of genus of prehistoric cartilage fish
References
External links
- "Galeocerdo cuvier". Integrated Taxonomy Information System . Retrieved April 7 2006 .
- Tiger shark, Galeocerdo cuvier in Encyclopedia of Life
- Integrated Learning General Information. Retrieved 22 January 2005.
- "Different diet information" Shark Info. Retrieved 22 January 2005.
- "Tiger shark development program in Hawaii". Retrieved 22 January 2005.
- "Tiger shark: Fact File" from National Geographic
- Track research on tiger sharks
- Tiger shark image
Source of the article : Wikipedia
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