Grass goldfish is also called golden crucian carp, which is the ancestor of goldfish and is similar in size to ordinary crucian carp. Its own physique is very strong, and its resistance and adaptability are very strong, and its feeding habits are relatively wide. It does not need special fine management, and it is convenient to raise. It can be raised in fish tanks or fish ponds, and it can also be artificially propagated.

Guppy is a small tropical fish. Although its body is not big, it has a beautiful tail. This kind of fish has many kinds and rich colors. Compared with common tropical fish, it can endure the environment of 17 ℃, so it is not difficult to raise, and the requirements for water quality are not high, so it is very suitable for beginners to raise.

Zebrafish is a common tropical ornamental fish with spindle-shaped body, small head and blue stripes. This kind of fish is gentle in temperament, and it swims almost all the time. It doesn't require high water quality. It can be kept clear by laying some pebbles under the water, and the feeding temperature can be between 20-23 ℃.

Arowana is a fish of the family Percidae, which is small in size. Because it can breathe on the water surface, it has low requirements for dissolved oxygen and water quality. Its feeding habits are miscellaneous, and its temperament is fierce. It can only be mixed with tropical fish with mild temperament. Although its life span is not long, it is easier to reproduce.

The scientific name of Mary fish is jasmine killifish, and it is closely related to guppy. It has strong adaptability to the environment and good pollution resistance, so it has low requirements for water quality. It usually feeds on algae and plant debris, and is mainly distributed in the coastal areas of the United States and Mexico in the wild.