Here are some of the most popular freshwater fish species that are commonly kept in aquariums, each with unique characteristics and care requirements.
A common rule of thumb for how many freshwater fish you can keep in an aquarium is to allow about 1 inch of fish per gallon of water; however, this can vary depending on the specific fish species, their adult size, activity level, and bioload, with heavily planted or densely stocked tanks often needing more filtration and swimming room.
Overview The Betta (Betta splendens), or Siamese fighting fish, is one of the best-known aquarium fish. Native to central Thailand, where it lives in rice paddies, swamps, ditches and slow streams. Wild fish reach about 2.8 in (7 cm) standard length. Long-finned...
Overview The Black Angelfish is a solid black color form of the freshwater angelfish (Pterophyllum scalare). Wild angelfish come from the Amazon basin in Brazil, Peru and Colombia, and from the Guianas. Grows to about 6 in (15 cm) long and taller with the fins, so it...
Overview The Duboisi Cichlid (Tropheus duboisi), or white-spotted cichlid, is a Lake Tanganyika cichlid. Juveniles are black with white spots and adults develop a pale band. Lives in rocky areas, in deeper water than other Tropheus. Grows to about 5 in (12 cm)...
Overview The Dwarf Gourami (Trichogaster lalius) is a colorful labyrinth fish. Males have red and blue bars. Native to Pakistan, northern India and Bangladesh, in slow, heavily planted ponds, swamps, ditches and canals. Grows to about 3.5 in (8.8 cm) standard length....
Overview The Convict Cichlid (Amatitlania nigrofasciata) is a hardy Central American cichlid with bold black bars. It is one of the most familiar cichlids in the hobby. Native to Guatemala, Honduras, El Salvador, Nicaragua, Costa Rica and Panama. Grows to about 6 in...
Overview The Discus (Symphysodon aequifasciatus and related Symphysodon species) is a disc-shaped Amazon cichlid prized for its color. Wild fish live in slow tributaries and forest pools along the Rio Solimões and Amazon. Grows to about 6 in (15 cm) long and nearly as...
Overview The Firemouth Cichlid (Thorichthys meeki) is a Central American cichlid known for its bright red-orange throat, which it flares to display. Native to lowland waters from southeastern Mexico, around the Yucatán Peninsula, to northern Belize and Guatemala....
Overview The Electric Yellow Cichlid (Labidochromis caeruleus) is a bright yellow mbuna from Lake Malawi. The yellow form comes from a short stretch of the northwestern shore, between Charo and Lion's Cove. Grows to about 3.9 in (10 cm) standard length. One of the...
Overview The Honey Gourami (Trichogaster chuna) is a small, peaceful gourami. Breeding males turn honey-orange with a dark throat. Native to the Ganges and Brahmaputra basins of northern India and Bangladesh. Grows to about 2.2 in (5.5 cm) standard length. A good...
Overview The Pearl Gourami (Trichopodus leerii) is a graceful gourami covered in pearly white spots. Breeding males develop a deep orange throat. Native to lowland swamps of Thailand, Malaysia, Borneo and Sumatra. Grows to about 5 in (12 cm) standard length. Hardy,...
Overview The Paraguay Eartheater (Gymnogeophagus balzanii) is a hump-headed South American cichlid that sifts sand for food. Native to the Paraná and Uruguay basins in Brazil, Paraguay, Argentina and Uruguay. Grows to about 8 in (20 cm) standard length. Best for...
Overview The Opaline Gourami is a captive-bred color form of the three spot gourami (Trichopodus trichopterus). It has a marbled blue pattern. Wild three spot gouramis live in slow, weedy lowland waters of the Mekong basin and Southeast Asia. Grows to about 6 in (15...
Overview The Kuhli Loach is a slender, eel-like loach with orange and dark bands. It is sold as Pangio kuhlii. Most trade fish are actually Pangio semicincta from Peninsular Malaysia, Sumatra and Borneo. True P. kuhlii is from Java and is rarely exported. Grows to...
Overview The Kribensis (Pelvicachromis pulcher), or krib, is a colorful West African dwarf cichlid. Females show a cherry-red belly. Native to Nigeria and Cameroon, in still and slow, heavily vegetated waters. Grows to about 3.9 in (10 cm) standard length. Most fish...