Classification: Kingdom Animalia Phylum Chordata Class Chondrichthyes Order Carcharhiniformes Family Carcharhinidae Genus Galeocerdo species cuvier
Common Name Tiger Shark
Morphology: One of the largest sharks in the world, the tiger shark is named for the characteristic, vertical striped markings that run along the length of its body. These markings are most pronounced in juvenile tiger sharks, but fade with age, being generally absent in adults of over three meters in length. In overall coloration, the adult tiger shark is bluish-green to dark grey above, and yellowish-white to stark white below. The body shape is distinctive, with a broad head and upper body, becoming increasingly slender towards the tail. They have bilateral symmetry.
Distribution Map:
Ecological Importance: Sharks are often the apex predator in the oceanic ecosystem, meaning that they keep the ecosystem balanced and allow populations of other creatures to maintain healthy levels. Sharks regulate the quantity and health of other marine life, helping to keep fish stocks in the ocean healthy. They tend to feed on weak, old and unhealthy fish, which stops the spread of disease among fish populations. This eliminates a lot of the competition, meaning a stronger gene pool and a more diverse population of sea creatures will survive. Although for some time it has been thought that removing sharks from the oceans would result in a huge increase in fish population – some scientists now think the opposite would happen; and the existing populations would be wiped out by disease.Being at the top of the food chain, their role is vital to ensure that all parts of the food chain lower down are controlled. For example, algae produces around half of the oxygen that we breathe. Without sharks controlling the food chain balance, the oceans could become overrun with algae, drastically oxygen quantities in our atmosphere. The knock on effects of this could be devastating for all life on Earth.
Interesting Facts: --Tiger sharks are named that way because of their tiger-like, black stripes that cover the body of young animals. As animals become older, these stripes fade away, becoming almost invisible in adult animals. --The tiger shark has a broad tolerance for a variety of marine environments, but generally prefers murky waters in coastal regions. It can often be found in river estuaries, harbors and other inlets, as well as in coral atolls and lagoons. Individuals also occur offshore, especially during oceanic movements between islands, and have been reported to depths of up to 350 meters --Like many shark species, the fins of the tiger shark are highly prized in Asia for making “shark-fin soup”. In addition, its meat is consumed, its skin is used to make leather, and its liver is taken as a source of Vitamin. Fortunately, this species is relatively fast growing and produces large numbers of young per litter, hence it is believed to be better able to tolerate exploitation than some sharks. In addition, in areas where the numbers of adults have been reduced due to fishing, juvenile tiger sharks have been found to be more abundant, as predation from the adults is lessened. --While there are no specific conservation measures in place for the tiger shark, several conservation organisations such as Save Our Seas Foundation, Shark Research Institute, The Shark Trust and Bite-back are working to conserve sharks worldwide. Through campaigns to reduce fishing pressure, stop wasteful finning practices and correct misperceptions, they are helping to ensure the future of these remarkable animals. --Tiger sharks are the second most dangerous species of sharks for humans. Unlike great white sharks (which are the most dangerous), tiger sharks will often eat their victim after attack. Luckily, encounters between tiger sharks and humans are rare.
Biology: --The tiger shark is known for its voracious appetite and indiscriminate feeding habits, the tiger shark has been known to consume an incredible array of items, from standard prey such as fish, turtles and marine mammals, to human rubbish, including burlap sacks and car license plates . Such behavior enables this species to overcome the problem of food shortages, which can affect sharks that feed more selectively Unfortunately, the tiger shark’s curiosity and tendency to sample such a wide variety of objects has meant that on occasion it has been responsible for attacks on humans.
--The tiger shark is nocturnal , moving to inshore locations where it engages in active hunting of prey, as well as scavenging, before returning to deeper waters where it spends the day
--Home ranges appear to be very large, with electronically tagged tiger sharks released in Hawaii swimming over 16 kilometers within a day of being released, and taking between two weeks and nine months to revisit the release area.
--Tiger sharks are ovoviviparous, receiving nourishment from a yolk sac. Once the yolk sac nutrients are exhausted the embryos are thought to gain further nourishment from secretions produced by the uterus until birth takes place. The gestation period takes between 14 and 16 months, with births taking place in the Northern Hemisphere between April and June, and in the Southern Hemisphere from November to January. Litter sizes vary between 10 and 82 pups, with the newborns measuring between 0.5 and 1.05 meters
Economical importance:
Like many other sharks, tiger sharks are used for what is called Shark finning. after the sharks fin is cut off they are thrown back into the ocean to die. it may take days for them to "drown" because sharks need to keep moving, some even starve to death. Their fins are used as the principal ingredient of Shark fin soup, an Asian delicacy. Demand for shark fin soup has rocketed in recent years. Shark fin soup can easily cost $100 a bowl. Traders can make a lot of money from shark fin, but it is the restaurant owners who make the most, because they sell it at a very high price.
Vocabulary: Bilateral Symmetry: the property of being divisible into symmetrical halves or either side of a unique plane. Nocturnal: occurring or active at night ovoviviparous: (of an animal) producing young by means of eggs that are hatched within the body of the parent. Gestation the development of something over a period of time. Shark Finning: the removal and retention of shark fins and the discard at sea of the carcass.