There is only one species of Cetaceae. The whale shark Rhincodon typus is the largest fish in the world, with a length of 20 meters (usually about 8 meters), a flat head and a wide mouth. Like Pteristidae and Pteristidae, it feeds on plankton. The mouth can be opened up to 1.5 meters, with 300 rows of tiny teeth. The gill harrow is spongy and can filter 600 cubic meters of seawater per hour.

Whale sharks live in tropical and subtropical oceans and are found in the Caribbean, the east and west coasts of Africa, the Philippines and Taiwan Province Province. Generally, he only moves and swims alone near the sea. The huge blue-gray body has obvious skin ridges, yellow spots and stripes on both sides, and the first half of the caudal fin is obviously upturned.

Whale sharks spawn. Small fish are 40-60 cm long at birth, usually reach sexual maturity in 30 years, and their life span can reach 60- 150 years. They are also endangered animals because of their weak reproductive ability.

The earliest recorded whale shark was found off the coast of South Africa in 1828. It was not until 1984 that Cetaceans became a formal family.