Search results
Results From The WOW.Com Content Network
Having the ability to keep their warmth helps them as predators as well. Another group of sharks, known as the mackerel sharks are able to warm their blood. These mackerel sharks retain their blood by using a heat exchange system called rete mirabile. The body temperature of mackerel sharks can be up to 10 o higher than the surrounding water. [10]
Sandbar sharks usually have heavy-set bodies and rounded snouts that are shorter than the average shark's snout. Its upper teeth have broadly uneven cusps with sharp edges. Its second dorsal fin and anal fin are close to the same height. Females can grow to 2–2.5 m (6.6–8.2 ft), males up to 1.8 m (5.9 ft).
Many sharks can contract and dilate their pupils, like humans, something no teleost fish can do. Sharks have eyelids, but they do not blink because the surrounding water cleans their eyes. To protect their eyes some species have nictitating membranes. This membrane covers the eyes while hunting and when the shark is being attacked.
Greenland sharks have also been found with remains of moose, polar bear, horse, and reindeer (in one case an entire reindeer body) in their stomachs. [11] [24] [20] The Greenland shark is known to be a scavenger and is attracted by the smell of rotting meat in the water. The sharks have frequently been observed gathering around fishing boats. [11]
It inhabits shallow waters off northern Australia to a depth of 170 m (560 ft); smaller sharks frequent sand and seagrass habitat and shift to coral reefs as they grow older. A slim, drab species reaching a length of 1.1 m (3.6 ft), it has sickle-shaped fins with dark tips on the second dorsal fin and caudal fin upper lobe.
In fact, at SeaWorld Orlando, kids can touch a shark, learn about different species of shark and even dine at a restaurant where sharks swim past throughout their meal.
Typically, basking sharks reach 7.9 m (26 ft) in length. It is usually greyish-brown, with mottled skin, with the inside of the mouth being white in colour. The caudal fin has a strong lateral keel and a crescent shape. Other common names include bone shark, elephant shark, sailfish, and sunfish.
Some sharks are so flexible, they can bend right around and touch their tails with their snouts. Shark skin is so rough that in the past it was used to make a type of sandpaper, called shagreen. Without their fins, sharks wouldn’t be able to stay the right way up. They’d roll over in the water. Most sharks never close their eyes.