Card shark questions skin#

The wider it opens its mouth, the less leverage is available for the jaw muscles and the weaker the bite becomes. An alligator only exerts maximum bite force when its jaws are almost shut. That’s a huge force – twice as much as the largest alligators, which have the strongest bite of any land animal, and more even than current estimates of the bite of the T-rex. Most of the time, sharks sit firmly at the top of the food chain.Ī six-metre shark, such as a great white, can exert more than 18,000 newtons of force with a bite. Orca (killer whales) have been known to attack and kill great white sharks, and sperm whales are also occasionally believed to kill sharks. Hammerhead sharks dine almost exclusively on rays, which are closely related to sharks.ġ8. But great whites, tiger sharks and mako sharks will eat tuna, seals, sea lions, dolphins and even smaller shark species. Most shark species have fairly specific diets – blue sharks mainly eat squid, for example.

Do sharks ever attack/prey on other shark species? Even the normally solitary hunting species can congregate in groups around a rich food source or to breed.ġ7. Scalloped hammerheads can form schools of up to 100 sharks, for example. Are sharks solitary or do they live in groups? The spiny dogfish uses its spine to co-ordinate swimming, so that it can rest its entire brain without stopping.ġ6. Others may rest one half of their brain at a time, like dolphins do. Some species rest on the seabed, but their eyes will still follow nearby swimmers. The mako shark is the world’s fastest shark An open-water hunter that chases fast fish such as tuna, it can reach up to 32km/h (20mph). Their saw snouts become very easily entangled in fishing nets. What’s the most endangered species of shark?īoth the large sawfish and the common sawfish are listed as critically endangered by the International Union for Conservation of Nature. Sharks definitely do get cancer, but there’s some evidence that a compound called angiogenin, an inhibitor in shark cartilage, reduces the ability of tumours to grow.ġ3. This makes it look like a much smaller fish silhouetted against the sky.ġ2. The brightest is the cookie cutter shark, which glows over its entire stomach, except for a dark band round its neck. Yes, a few species use bioluminescence to lure prey. It lives in theĬaribbean Sea and grows no larger than 20cm (7.8in). What’s the smallest species of shark?Ī kind of deepwater dogfish shark called etmopterus perryi. But the whale shark is estimated to live for up to 100 years.ġ0. Most species live for between 20 and 30 years. These ‘dermal denticles’ generate tiny vortices on their trailing edges as the shark swims and this vastly reduces the shark’s drag through the water.

Card shark questions skin#

Shark skin is covered with scales like other fish, but shark scales are made from dentine and actually resemble tiny teeth more than scales. The whale shark is found in tropical and warm waters throughout the world, except the Mediterranean.Ĩ. As well as being the largest shark, this is also the largest fish. The extra buoyancy is supplied by dynamic lift from the shark’s fins as it swims. The amount of squalene oil stored there is adjusted to leave the shark slightly heavier than water. Sharks don’t have a swim bladder like other fish, so they use their liver instead. Their muscles are anchored directly to the inside of their tough skin. Sharks belong to the elasmobranch group of fish that have lighter, more flexible cartilage in their skeleton, instead of bone. A new species of shark, skate or ray is identified approximately every two weeks. True sharks are classified in the superorder selachimorpha and there are more than 440 species alive today. A great white shark can get through up to 50,000 teeth in its lifetime. They are designed to be disposable and are continually replaced like a conveyor belt from the back of the mouth.

Shark teeth aren’t embedded in the jaw, but are attached to the skin. How many teeth does a shark get through in a lifetime? Why is this number so high? Notice the dark spot level with end of the mouth and in line with the eyeģ.