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
Sharks are afraid of dolphins when outnumbered because they like to eat animals that are much smaller than them, including baby dolphins, but adult dolphins will protect their young by trying to kill a shark any time they see one. Dolphins are usually successful at killing the sharks that they find because they attack in groups, ramming their bodies into the shark until it dies.Full Answer >
According to the Shark Foundation, sharks are found in most of the Earth’s oceans and seas. The highest shark biodiversity occurs in the warm waters of the tropics, but many species are found in Arctic and Antarctic waters as well. Some sharks, for example bull sharks, are even capable of swimming up freshwater rivers and streams.Full Answer >
There are 465 known species of sharks that display different physical characteristics. Most are identifiable by their darker upper sides that blend with the water above and their white or lighter-colored undersides that blend with the sea below, in addition to their fins, side gill slits and rows of sharp teeth. Shark skeletons are composed of cartilage, a light and flexible tissue.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 >