Aquarium fish

Aquarium fish are fish used in aquariums. They can be freshwater or saltwater. Some fish, such as the betta, can be aggressive.

Goldfish

The goldfish (Carassius auratus) is a freshwater ray-finned fish in the family Cyprinidae of the order Cypriniformes. It is a great fish for aquariums, and is one of the most popular aquarium fish. They have become an invasive pest in parts of North America. The average lifetime of a goldfish is ten to fifteen years.

Pike topminnow

The pike topminnow (Belonesox belizanus) is sometimes found in the aquarium trade, but it isn't an easy aquarium resident.

Green swordtail

The green swordtail (Xiphophorus helleri) is a freshwater aquarium fish in the family Poeciliidae of the order Cyprinodontiformes. Green swordtails are very popular in aquariums.

Pygmy sunfish

Elassoma, the pygmy sunfishes, are popular as aquarium fish because of the males' iridescent colors and fascinating breeding behaviors.