Sharks are very diverse and are distributed literally in all parts of the oceans. Currently, there are about 450 species of sharks in the world. Some species are able to live in fresh waters. The sizes of sharks, depending on the species, vary widely - from 15-17 cm to 20 m. A striking distinctive feature of these fish is the structure of their teeth. These they received their fame and notoriety thanks to several species that differ from others in their gigantic size and aggressiveness.
Instructions
Step 1
Sharks are one of the most ancient representatives of the fish family, considered, moreover, to be rather primitive creatures. They are predators by nature, and are well adapted to this lifestyle. Many sharks have an excellent attack tool - several hundred sharp teeth that are replaced as they fail, and scaly skin so rough that it is sometimes used as an abrasive.
Step 2
Most shark species prefer medium-sized fish as prey and categorically avoid attacking any larger animals. At the same time, the whale and giant sharks, which are the largest representatives of the family and, in general, the largest fish, are filter feeders. They feed mainly on plankton, and sometimes squid and small fish. Bigmouth, giant and whale sharks have a "filter apparatus" in their mouths instead of predatory teeth, which allows them to capture at once a large number of small planktonic organisms that drift in the water column near the surface. That is why large species also live near the surface of the water. Despite their size, they are not at all dangerous to humans, and the whale shark, moreover, is good-natured - it allows you to touch and even ride on it.
Step 3
The tiger shark is a large predator, reaching a length of 5 m, a real ocean scavenger. She is considered the culprit for most of the attacks on humans. Tiger sharks are very voracious and indiscriminate in their food. They eat squids, lobsters, crabs, a wide variety of fish, bivalves and gastropods, stingrays, sea and migratory birds, sea snakes and turtles, which in this case cannot be saved even by the shell. They attack dolphins and seals. Parts of crocodiles and domestic animals, and even individuals of their own species, were found in the stomachs of tiger sharks. They can feed on garbage and carrion.
Step 4
The white shark is a predator reaching a length of 6 m. It preys on marine mammals, fish and seabirds. She is also credited with attacks on humans, but it is clear that humans are not among the food preferences of the great white shark.
Step 5
Atlantic polar sharks eat seabirds, seals, licods, rays and flounders. They hunt bottom fish and animals - cod, food, perches, octopuses. Common prey are pollock, blue whiting, gobies, chanterelles living closer to the ocean surface.
Step 6
Bottom shark species feed on crustaceans, polychaetes, cuttlefish, and sometimes typically bottom fish - eels, flounders. The species inhabiting the lower part of the shelf and at depths of 150 - 350 m eat benthic crustaceans and fish - hake and perch.
Step 7
The oldest representative of the genus is the frilled shark, more like a sea snake. The frilled shark reaches a length of 2 m. It lives at a depth of 1570 m. It feeds on fish, squid, octopus and other smaller shark species. Once in the stomach of a caught frilled shark, a Japanese cat shark was found, weighing 560 kg.
