鲨鱼

这是一篇关于鲨鱼的思维导图，介绍了鲨鱼的定义、鲨鱼的形状、鲨鱼的危险性、频临灭绝、鲨鱼的保护等班内容。

About Sharks

• What is it
  • Definition
    • Sharks belong to the cartilaginous subclass of Vertebrate phylum. They are marine, and a few species enter freshwater. They are a group of fast-swimming medium and large marine fish.
  • Shape
    • The body is fusiform with gill slits on both sides of the head, but it resembles a common fish. With a few exceptions, the typical shark has hard, dark gray skin with tooth-like scales that make the skin appear rough. The tail is strong and powerful, asymmetrical and upturned; the fins are pointed; the snout is pointed and protruding, with a crescent-shaped mouth and triangular fangs under the snout. Sharks have no swim bladders and need to swim constantly to avoid sinking to the bottom.
  • Why attack humans
    • It is not that sharks actively attack humans, but it is usually caused by humans entering the shark's range to interfere with the shark's activities or attracting a lot of human blood in the sea after a capsize accident.
• Dangerous
  • The great white shark is a carnivore and potentially dangerous to humans
  • Jaws strengthened people's long-heid idea of the great white shark as a dangerous animal
• Endangered
  • Because of the fear of shark, some people started fishing for shark, killing as many as they could
  • Shark fins have medicinal value, and shark fishing has brought extremely high profits to fishermen
• Protection
  • Peter Benchley, the man who wrote the book the film Jaws was based on, admitted that his book was wrong about sharks
  • Nowadays, more and more people work together to protect the great white shark as they can
  • Experts have proved that sharks don't see pople as food, and they attack people by mistake