Crustaceans include: fairy shrimp, water flea, cyclops, fish lice, barnacles and copepods, crayfish, lobsters, shrimps, tidal worms, marsupials, sand fleas and ground beetles.

There are many kinds of crustaceans in the world, about 26,000 species. Shrimp, crab and other crustaceans are rich in nutrition and delicious, which has high economic value. Some crustaceans are also food for economic animals such as fish. Among crustaceans, some species are harmful, such as fish lice, which are very harmful to fish.

Breeding methods of crustaceans;

Crustaceans reproduce by laying eggs. Eggs of crustaceans in seawater hatch into very small larvae, which are different from adults. Young crustaceans in fresh water are similar to adult crustaceans, but their bodies are smaller than those of adults.

Small crustaceans are very important as the main food of fish. Lobster, crab and shrimp are very good foods for human beings, and many people also eat crayfish.

Crustaceans are also used as "cleaners" to help keep beaches and streams clean. On the other hand, some crustaceans are very dangerous pests. They destroy crops or enter docks and seawalls to cause damage.