1, fish is the oldest vertebrate, the world's fish species **** about 20,000 species. According to the class can be divided into two general class, namely, jawless and jawed general class, jawless general class including round mouth class, armored fish class, jawed general class including shield skin fish class, cartilaginous fish class, bony fish class, spoke fins fish class and so on. According to the water can be divided into saltwater fish and freshwater fish.

2. Carp. Carp is mainly plant-feeding omnivorous fish, preferring to travel in groups and choose food to live in, crucian carp is an omnivorous fish living in freshwater, crucian carp life level belongs to the bottom of the fish. Generally, it swims, feeds and inhabits underwater. When the temperature and water temperature are high, it will also swim and feed in the lower and upper middle layers of the water.

3, grass carp. Grass carp generally like to live in rivers, lakes and other waters in the middle and lower layers and near the shore of the region with more water plants. With the habit of river and lake migration, grass carp often group foraging, gluttony, as a typical herbivorous fish. Fry stage ingestion of zooplankton, juvenile period and eat insects, earthworms, algae and duckweed.

4, chub. Chub, a typical filter-feeding fish, chub belongs to the pelagic fish, chub mainly feed on zooplankton, fry stage mainly eat zooplankton, slowly grow up and gradually turn to eat phytoplankton, and like to eat grass carp feces and put in the chicken, cow dung. Soybean dregs powder, bran and rice bran and artificial micro-granular with feed.

5, bighead carp. Bighead carp, also called chub, grows in freshwater lakes, rivers, reservoirs and ponds. Mostly distributed in the middle and upper layers of freshwater areas, filter-feeding, mainly eat rotifers, branchiostoma, copepods (such as cyclops) and other zooplankton, but also eat part of the phytoplankton (such as diatoms and cyanobacteria) and artificial feeds, is a typical plankton feeding fish.

6, cyprinids. Cyprinid habit is not active, usually inhabiting the lower and middle layers of the water, food to snail, mussels, clams, clams, etc., but also prey on shrimp and insect larvae. In the fry stage, the main zooplankton for food.