Sharks have adapted to their habitat by having streamlined, hydrodynamic bodies. Their skeletons aren't made of bone like other fish but cartilage. This makes their skeletons lighter and more flexible.Know More
Like most other fish, sharks are cold-blooded. This gives them a low metabolism and allows them to fast for weeks. However, when it's time to eat, sharks benefit from having short but wide esophagi and jaws that aren't firmly attached to their skulls. This allows sharks to gulp down their prey whole or in large chunks. Sharks' teeth are also replaced constantly.
Sharks' livers, fins and constant movement keep them from sinking. The liver is enormous and filled with a substance called squalene, which helps to keep the shark buoyant.
Sharks also have an astonishing sense of smell and can smell blood in the water as far as one-quarter of a mile away. They also have a tapetum lucidum, a membrane at the back of the eye that lets them see in low light. They can change the size of their pupils to adjust to light conditions, which is an adaptation not found in other fish.
Sharks can also sense electrical fields through organs in their heads called ampullae of Lorenzini.Learn more about Sharks
The size of a shark depends on its species. The largest living shark, the whale shark, averages 31.82 feet long. The extinct megalodon was even bigger at about 60 feet long. The smallest shark is the dwarf lanternshark, which is only 6.7 inches long.Full Answer >
All species of sharks are carnivores, not omnivores. On rare occasions, a shark will dine on something other than meat, such as seaweed, but it happens so rarely that it's not common enough to change the shark's classification.Full Answer >
The top speed of a shark varies between the individual species. There are over 400 species of sharks in the world's oceans, but the fastest known species is the shortfin mako and the slowest is the Greenland shark.Full Answer >
When sharks mate, the male grabs the head of the female with his teeth and inserts pelvic fins called "claspers" into her reproductive area. The male has sacs that are filled with seawater that help to shoot his sperm through the female to ensure reproduction. The two sharks stop swimming and have to stay connected for several minutes. They sometimes fall to the ocean floor in the process.Full Answer >