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 >
If sharks became extinct, there would be ecological repercussions, such as small animal extinction, algae overgrowth and coral reef death. Sharks are a crucial part of the marine ecosystem and are necessary for the world's oceans to operate.Full Answer >
Different sharks communicate within their own species in different ways; for example, the Smithsonian Museum of Natural History reports that great white sharks can communicate with each other by gaping their jaws while the University of Michigan says that gray reef sharks communicate using their senses of sight and touch. In general, sharks are not believed to have linguistic communication abilities, relying instead on other senses to communicate.Full Answer >
Shark reproduction varies from once each year to at irregular intervals several years apart. Mating also varies among species, from those that mate year-round to those that prefer certain seasons and regions, often affected by migration.Full Answer >