Sharks existed on Earth as early as 300 million years ago before the emergence of dinosaurs, and have been around for more than half a billion years now, and they have remained virtually unchanged for nearly 100 million years. Sharks, called sharks, sharks, sandfish in ancient times, are the behemoths of the ocean, so called ? Wolf of the Sea? Do you know what are the most ferocious sharks in the world? Here are five ferocious sharks.

First, the great white shark, also known as the man-eating shark, is the largest predatory fish, up to 6.5 meters in length, weighing 3200 kilograms, the tail is crescent-shaped, teeth large and serrated edge, triangular shape, tooth length of 10 centimeters, large offensive sharks. But because of its particularly large type, can be considered to have been the ultimate food chain predator, that is, the highest level of consumers. Great white sharks are found in tropical and temperate zones of the oceans and generally live in open ocean areas, but often enter inland waters. Their favorite predators are seals, sea lions, and occasionally dolphins and whale carcasses.

Secondly, the bull shark, smaller in size, the body is relatively broad compared to other sharks, the trunk is thick, the whole body is spindle-shaped. The back of the body is side dark gray, the belly is grayish white. Male bull sharks can grow up to 2.1 meters long and weigh 90 kilograms. Females are larger, up to 3.5 meters long and 230 kilograms. Bull sharks have a broad, flat head with a depression at the base of the tail. Bull shark eyes are very round with well-developed transient membranes. The anterior nasal valves are broadly triangular; there are no oronasal grooves or tentacles. Bull sharks are found in tropical and subtropical coastal waters anywhere from western Australia to Brazil.

Third, tiger sharks, Chondrichthyes, tiger shark family, characterized by a thick, hard spine on the leading edge of each of the two dorsal fins. There are about 10 species. Marine, benthic, found almost everywhere except the Mediterranean and Atlantic. Usually 3.25-4.25 m, up to 6 m long. Both palates with sharp teeth, the anterior ones incisor-like, the sides molar-like. Feeds on invertebrates such as sea urchins and crustaceans.?

Fourth, the whale shark, whale shark family whale shark genus of sharks. The total length of up to 20 meters, is the world's largest fish. Body surface scattered light-colored spots and crisscrossed light-colored bands, like a checkerboard. The nostrils are located on both sides of the upper lip and appear inside the mouth. Teeth are numerous and small, arranged in multiple rows. Gill slits 5 pairs, gill slits basally large, almost reaching the dorsal and ventral margins of the body, the last pair of gill slits located in front of the base of the pectoral fins. Dorsal fins 2, without spines, the first dorsal fin is located in front of the ventral fin, with an anal fin. The caudal peduncle is laterally ribbed and the caudal fin is crescent-shaped, with the lower lobe shorter than the upper lobe. As in the whale shark, there are two dorsal fins of different sizes, the pectoral fins are large and located under the third pair of gill slits, the ventral fins are small, the caudal fins are forked, and the mouth is wide and terminal, with gill rakers like sponges.

Fifth, the great blue shark, body slender, 2-4 meters. Body nearly spindle-shaped. Head broad and flat, head length less than a quarter of the full length; muzzle triangular, long and pointed protrusion. Eyes small, round. Mouth semilunar, maxillary teeth triangular, margins serrulate; mandibular teeth narrower and pointed. There are 28-30 teeth in each of the upper and lower jaws. There are five gill pores. There are two dorsal fins, the first dorsal fin is not large, the upper angle is blunt and pointed, the lower angle is cuspidate; the second dorsal fin is smaller than the anal fin. The tail is elongated, with a depression in each upper and lower caudal fin. The pectoral fins are sickle-shaped. The ventral fins are small and nearly square. The dorsal and upper sides of the body are grayish-blue, the ventral and lower sides white. It is a fierce and agile swimmer. Abundant in temperate warm seas and tropical oceans. Commonly found at the surface, voraciously feeding on schools of fish, squid and other sharks.?