What kinds of sharks are there?

Hexagonida: There are about 5 species belonging to 4 genera and 2 families, including Hexagonidae and Chlamydomonas. In China, there are only 4 species belonging to 3 genera 1 family. Widely distributed in tropical and subtropical waters of the Pacific Ocean and Atlantic Ocean.

2. Rat Sharks: There are 5 families, including Cone-toothed Sharks, Kiss Sword Sharks, Mu Ye Sharks (Rat Sharks), Basilis Sharks, and Long Tail Sharks. There are 4 families, 6 genera and 8 species in China. Five pairs of gill holes. 2 dorsal fins, spineless; There are anal fins. There is no blink or blink in the eye. The vertebral body has radial calcified areas, and 4 non-calcified areas have no calcified spokes.

3. Heterodonta: only 1 family, 1 genus, 8 species. Distributed in tropical and temperate waters of the Pacific Ocean and Indian Ocean. There are two kinds of domestic tiger sharks: Japanese heteroodont shark and zebra heteroodont shark. Small and medium-sized sharks, up to 1.5m long.

Extended data:

Most sharks feed on marine animals such as fish. Sharks feed on injured marine mammals, fish and carrion, and destroy weaker members of animals. Sharks also eat garbage and other wastes left by ships. In addition, some sharks prey on various marine mammals, fish, turtles, crabs and other animals.

Great white shark is a predator who is good at camouflage. Great white sharks are not as flexible as other sharks because of their huge size. But the great white shark is an excellent hunter, because it can always surprise. Its upper body is dark and its lower body is bright, so they can sneak up on their prey through this protective color.

They sleep during the day and come out at night. Great white sharks are daytime carnivores. Other species, such as nurse sharks, force water through gills through stomata, providing oxygen-rich water so that they can breathe when they are still. The central test signal generator, the organ that dominates swimming, is located in the spinal cord, allowing sharks to swim unconsciously.

References:

Baidu encyclopedia-shark