White shark : Characteristics, habitat, breeding, food of the white shark
The white shark (Carcharodon carcharis) is the largest predatory fish that currently exists, capable of hunting large marine mammals that exceed it in weight. They are vertebrate animals belonging to the Chondrichthyes class. Therefore, its skeleton is of cartilaginous constitution.
The great white shark presents sexual dimorphism. Females are of greater length and weight, reaching a height of about six meters and a weight of about 1,905 kilograms. Males are smaller, measuring between 3.4 and 4 meters. It is one of the longest living elasmabranchs. Recent studies show that you can live up to 70 years.
Carcharodon carcharias: It lives in almost all tropical and temperate coastal waters, from 60 ° north latitude to 60 ° south latitude. It is a highly migratory animal, which attracts large crowds every year.
Its muscular body is adapted to swim quickly, reaching speeds of over 56 km/h. In this way, you can chase and capture your prey.
Due to its indiscriminate hunting, this shark is listed by the IUCN as a species highly vulnerable to extinction. This has led to a ban on fishing and marketing of their products in many countries.
Development
There are different opinions about the phylogeny of this species, thus giving rise to two main hypotheses. The first one states that Carcharodon carcharias has ca.rcharodon Megalodon as an ancestor. The teeth of this extinct species do not differ much from those of the white shark, although they were larger.
Advocates of this approach consider it a case of heterosexuality. The great similarities between the dental features and the large size of the two species led to a close evolutionary relationship between them.
The second hypothesis states that the Carcharodoncarcharias originated from an extinct species of shark, Isurus hastalis, known as the makro shark. The basis of this approach is the great similarity in the shape of the teeth of these two species.
The size and shape of the teeth of c. Karchari and I. Hastelis may be associated with convergent evolution, as a response to the shared predation of pinnipid mammals.
Recent investigation
Currently, few studies have been conducted with the intention of elucidating the evolutionary origins of the great white shark. New research proposes that the white shark is a distant relative of C. Megalodon, contrary to the view which suggests that it evolved from it.
Research involves comparative studies of species such as C. Carchari, I. Hastlis andc. Megalodon, based on the fine structure of teeth and their morphological analysis.
The results showed that there was no significant difference in the size of the dent in between. Hastlis andc. carpentry. Therefore, these studies confirm the hypothesis that the great white shark is a product of the evolution of the makro shark.
Carcharodon hubbly
In 1988, in the Pisco Formation, in the south of Peru, fossilized remains of a species named C. Hubli. They contain the partial skull of a shark that lived about 4.5 million years ago. The bone formation consists of a set of jaws with 222 teeth and 45 vertebrae.
The investigation determined, based on the size of its teeth, that Hubel's white shark was related to extinction. Hastlis. At the same time, it presents a feature in common with Carcharodon carcharias, their teeth adapted for the consumption of marine mammals.
Because it shares characteristics with both species, C.hubbelli is thought to be a type of infection between I.hastalis and C. carpentry.
Features
wing
Its dorsal fin has a triangle shape and is large. The caudal fin is homocercal, the last vertebra of which is attached to the bony structures that support the rays of the fin. Because of this, the tail is believed to be half moon shaped. The lower and upper parts of the tail are of equal size. Furthermore, they do not have a secondary keel under the caudal keel.
Face
White sharks have large eyes, proportionate to their body dimensions. The iris is dark blue. Its muzzle is strong and with a conical structure, which gives it a definite pointed shape.
Color
The back of this shark is brownish-black in color, which suddenly turns white in its abdominal region. Some species have a terminal gill slit, irregular shape and small dark spots.
The large part of the white shark has an oval black spot on the axial region of the pectoral fin.
This particular color makes it difficult for prisoners to see Carcharodon carcharias, as it blends in with the darkness of the ocean when viewed from above. From below, its white lower area allows it to camouflage its body with the glow of sunlight.
body temperature
The great white shark has adaptations to keep its internal temperature higher than the water that surrounds it. One of them is "Wonderful Network". It is a large network of veins and arteries, located on the lateral sides of the animal's body.
In this structure the cold arterial blood is heated when mixed with the venous blood that comes from its muscular system. Thus, the internal temperature can be several degrees higher than the external medium.
Dead body
It has a strong and fusiform body, with gill slits surrounding the head. Due to the characteristics of the respiratory system, the white shark requires constant watering of its gills.
The skin is rough and covered with dermal denticles, hard conical scales that curve towards the tail end of the shark.
This animal does not have a swim bladder, so they must be in constant movement. However, its liver is highly lipid, which facilitates the animal's buoyancy.
Teeth
Its teeth are erect, large and triangular. In the lower jaw they are slightly thinner. White sharks have a row of serrated teeth behind the main ones.
Newborns lack marginal teeth on the lower teeth. When the animal is in its juvenile stage, the teeth have small cusps.
Shape
Carcharodon carcharias: It presents sexual dimorphism, with females being larger than males. It measures between 3.4 and 4 meters, weighing between about 522 and 771 kilograms. Females are 4.6 to 4.9 meters in length and weigh around 680 to 1,110 kg.
The maximum size recorded for this animal was 6.1 m, with a length of 6.1 m, with an estimated weight of 1,905 kg.
Lorenzini's ampoule
These cetaceans have the ability to detect the electromagnetic fields emitted by animals while they are in motion. This is achieved thanks to the Lorenzini ampulla, which consists of a network of electroreceptor channels located throughout the body.
Inside each ampoule is a gelatinous substance and sensitive cells, which capture changes in temperature and electromagnetic stimuli. The ampula of Lorenzini forms the group, an opening on the outside of the animal's body through a black hole.
In great white sharks this ampule is highly developed, capable of detecting variations of up to half a trillionth of a volt. In a short distance, he is able to feel the heartbeat of an animal that is nearby.
Habitat and Distribution
The great white shark is found in most parts of the seas and oceans, with a large concentration in the warm waters of the coast. They are pelagic animals, living in moderately temperate waters or near the surface, as much as possible confined to the seabed.
They could also spread to the open ocean, off the coast and islands near the ocean and the sub-Antarctic Borealis. Its range extends from the intertidal and surf lines to the farthest part of the coast.
Carcharodon carcharias can be found on the surface, or submerged up to 1300 m. You can enter saline estuaries and bays as long as it is not during the low tide season.
It was previously thought that these marine fish were territorial predators of the coast. However, recent studies suggest that the white shark migrates to other locations, perhaps due to mating or a lack of food in its native region.
An example of migration is one that demonstrates Carcharodon carcharias swimming from the South African coast to the south of Australia, returning after a year.
Geographical situation
Great white sharks are found in South African waters, particularly in KwaZulu, Namibia, the islands of Dior and Mozambique. They are also commonly found in western and eastern Australia, the Japanese archipelago and New Zealand.
With respect to the Pacific, it extends from Siberia to New Zealand, the Marshall Islands and the Hawaiian Islands.
The eastern Atlantic is also inhabited by white sharks, including the Mediterranean Sea from France to South Africa. There they are located in the western region and the center of the Tyrrhenian Sea, in the Sea of Marmaray and the Strait of Istanbul.
In the Indian Ocean, they live from the Red Sea to South Africa, Seychelles, Réunion and Mauritius.
Occasionally, it may encroach into boreal and cold waters, including the coastal region of Canada and Alaska.
In the western Atlantic, it is widespread from Newfoundland to Florida, the Bahamas, the northern Gulf of Mexico, and Cuba. It is also found from Brazil to Argentina.
Danger of extinction
Carcharodon carcharias has been subjected to indiscriminate hunting, resulting in a significant reduction in populations in their natural habitat.
Worldwide, they are protected by CITES Appendix II. This body, since 2002, regulates and prohibits the exploitation of white sharks.
The International Union for Conservation of Nature classifies the great white shark as near extinction in its natural habitat.
Causes
There are many factors that put this animal at risk of extinction. The great white shark is often associated with fatal attacks on humans.
As a result, man usually treats his prey as a trophy or may make it part of a sporting activity. In addition, the casual catch is added to the fishing net.
Their jaws and teeth have high commercial value. Meat is consumed as an exquisite dish; The famous shark fin soup is prepared with fins. The bones are used to make fishmongers. The oil is extracted from the liver and the skin is used to manufacture leather goods.
Another factor influencing the decline of white sharks is the low fertility rate, which is determined, among other things, by their late sexual maturity.
Work for protection
This marine animal is protected in Israel, Australia, New Zealand, Malta, Namibia, South Africa and the United States. The laws that protect it are strict, however, the commercialization of various products derived from this species continues.
In 1999 Carcharodon carcharias was declared vulnerable by the Australian government. However, many states had already banned their hunting or the capture of any by-products.
New Zealand became involved in these conservationist actions, and those who caught the animal were subjected to heavy fines and time in prison. In mid-2015, the state of Massachusetts, in North America, banned netting, diving in cages and hunting great white sharks.
The most relevant challenge in determining conservation measures is the lack of accurate data relating to age, growth, reproduction and population data.
Because of this, researchers and conservationist organizations suggest that conservation measures be based on the "precautionary principle" until more reliable information is available.
classification
animal kingdom.
Saberino Bilateria.
Film cordado.
Vertebrate subphylum.
Chondrichthys superclass.
Chondrichthys class.
Subclass Elasmobranchii.
Order Laniformes.
Family Lamnidae.
genus Carcharodon
Species Carcharodon carcharias(Linnaeus, 1758)
Reproduction
It was previously estimated that females mature around 15 years of age and males around 12. Recent studies show that the female can breed at the age of 33 years and the male at the age of 26 years. In addition, its longevity is about 70 years. The reproduction rate of these sharks is very low. They are fertile for only 4 years, apart from becoming sexually mature at a late age.
A male differs from a female because it has reproductive structures called claspers. These are two and they are located in the pelvic fin. Through the clasp, the male transfers the sperm to the female's cloaca.
Reproductive process
Little is known about the breeding behavior of white sharks. Some females have bites on the flanks, back and pectoral fins. It can be interpreted as a scar resulting from intercourse. It is believed that the male captures the female in those areas during the copulation phase.
This species is commonly found in temperate waters during spring or summer. It consists of an oesophageal reproduction, where the embryo, inside the uterus, nourishes itself on eggs produced by the mother's ovaries. In utero, the embryo continues to develop until the moment of birth. The gestation time can be around a year. Usually between 3 and 4 pups are born, which can measure about a meter.
Feeding
The white shark is an epipelagic fish that lives in the ocean, in an area located between the surface and a depth of 200 m. They are carnivorous, feeding on fish (rays, tuna), cetaceans (porpoises, dolphins and whales) and pinnipeds (sea lions, seals and sea lions). Whale sharks such as sea turtles, otters, seabirds and other sharks also make up their diet.
Young species mainly consume fish and other elasmobranchs such as rays. This is because their jaws are not strong enough to attack large prey.
Carcharodon carcharias. It is known to harbor concentrations of some bony fish, bluefish, as well as to chase large quantities of sardines in their migratory movement in the KwaZulu-Natal province of South Africa. Whale carcasses are an important basis in the diet of white sharks, as their meat is rich in fat. However, this happens sometime, as whales die in areas far away from their habitat.
Hunting techniques
The white shark usually raises its head to the surface of the ocean to observe its prey. This behavior is known as spy jumping and is used, among other animals, to harbor seals (Phocaeta vitulina). After getting out of the water, they take it with their teeth and drag it down, until they drown. To drown an adult sea elephant, it cuts one of the obstacles. Then wait for him to bleed to eat.
Although most of the time his hunting movements are horizontal, he also does them vertically. In this way, they float vertically to the surface, making it difficult to see their prey. One of the reasons for the success of this technique is the surprise attack.
Sea lions (Zalophus californiae) are attacked from below, later strike them, drag them and ingest them. When they hunt sea turtles, they bite them through the shell, near a fin. That way, they sip it, then eat it.
Mistaken identity
Within a set of silhouettes, the white shark would prefer to attack the person who has the shape according to the "file" of images related to food.
This may explain the "misidentification" hypothesis, which states that humans are called animals. A diver, viewed from below, can be attached with a pinpin. As a result, the shark will strike a person who believes it to be a sea lion or seal. Scholars of the white shark argue that sharks kill objects they do not know to be a potential food.
Consumption pattern
There is a theory that raises a model for the way we eat Carcharodon carcharias. It was previously thought that the shark bit its prey and then released it. Once he was dying or had died, he proceeded to consume it.
Recent studies indicate that great white sharks may forage or discard their prey as a low-nutrient food. Keeping the prey in your mouth, you can decide this. The fact that this animal prefers fat to the muscle tissue of whales confirms that the priority for them is energy-providing foods.
Behavior
Carcharodon carcharias: It is usually a solitary species. Sometimes they can be found in pairs or small social groups of a temporary nature, where hierarchies exist.
These are based on the sex of the animal, its body size and seniority within the group. Thus, smaller specimens are controlled by larger ones, with females exercising dominance over males.
Newbies are ranked lower than sharks already in the group. The way the group builds is led by an alpha member with clear tasks and boundaries. When species from different groups meet, nonviolent interactions are often established between them.
Held
Very rarely is the white shark aggressive with members of the same species; They usually resolve conflicts with the domain display. However, bite marks have been found, which may be associated with warnings or domain signs.
They may have many behaviors to maintain their personal space. When an animal approaches, it has to make a cautious turn. In addition, they can swim in parallel, keeping a certain distance between them. If two sharks compete for a prey, one of them may use its tail to hit the surface hard, driving a large amount of water onto its opponent. They can even rise above water as much as two-thirds of their body, falling suddenly against the water.
This behavior can also be used during courtship to attract the female, to capture prey or to eliminate some external parasites.