What Kind of Fish Live in an Aquarium?

There are many freshwater and saltwater fish species commonly showcased in aquariums. It's important to think about what kind of fish you want to live in your aquarium, since different fish have different care requirements, and not all fish will get along with each other amiably. Never mix freshwater and saltwater tank conditions or freshwater and saltwater fish.

  1. Bettas and Gouramis

    • Bettas and gouramis, such as Siamese fighting fish and kissing gouramis, are anabantoid fish: they can breathe air from the surface of a tank as well as the water in the tank, so leave some open space above the water line in your aquarium if you're hosting some. These freshwater fish are also territorial, so don't mix males of the same species and don't put them in undersized tanks with other fish species.

    Catfish

    • Catfish, like corydoras and Chinese algae eaters, are often usefully employed in tank maintenance, cleaning the aquarium in the act of scavenging for food. Different freshwater species range widely in size, and some can be aggressive.

    Tetras

    • Tetras, such as glowlight tetras and neon tetras, are a member of the freshwater characin family that often prefer to live in schools of at least five fish. Tetras also tend to like fish tanks containing lots of plants.

    Cichlids

    • Cichlids, like freshwater angelfish and convict cichlids, are another freshwater kind of fish that tend to be territorial, and some prefer their own company to the exclusion of all others. Be careful in choosing cichlid species, as some don't tolerate other fish species, some don't tolerate other fish of the same species or sex and some don't tolerate any other fish at all.

    Cyprinids

    • Cyprinids, such as goldfish and koi, are a large and diverse family of fish with varying sizes and water temperature requirements between different freshwater species. Many are amenable to living in the same aquarium as other fish and fish species, but some are not.

    Guppies

    • Guppies and related freshwater fish like platys are often fast breeders, so keep males and females separate unless you want lots of little fish being eaten by larger fish in your aquarium. Use a breeding net or breeding box for separation if you want to breed them.

    Marine Angelfish

    • Marine angelfish are angelfish species, like bicolor angelfish and pygmy angelfish, that live in saltwater conditions. They are often territorial and usually quite hardy, though they won't tolerate adverse nitrogen conditions.

    Clownfish

    • Clownfish are saltwater fish that are also usually hardy, and can be relatively long-lived. Different species of clownfish don't mix well, as they will exhibit territorial aggression if placed in the same aquarium, especially in smaller tanks.