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 One of the most popular and recognizable aquarium fish. Lives in acidic forest streams, often stained with tannins (blackwater), with leaf litter and roots. Has a bright blue lateral stripe. The red pigment does not extend forward past the pectoral-fin base....
Overview The African Jewelfish (Hemichromis bimaculatus), also sold as the jewel cichlid, is a colorful West African cichlid that turns brilliant red when breeding. Found in small streams and canals along Africa's west coast, from southern Guinea to central Liberia....
Overview The Bala Shark (Balantiocheilos melanopterus), also called the tricolor shark minnow, is a silver, black-edged cyprinid, not a true shark. Native to rivers and lakes of Borneo, Sumatra and Peninsular Malaysia. Grows to about 14 in (35 cm) standard length, so...
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 Black Phantom Tetra (Hyphessobrycon megalopterus) is a peaceful, smoky-gray tetra with a black shoulder spot and large fins. Native to the upper Rio Madeira basin in Bolivia and western Brazil, and the Rio Paraguay basin. Grows to about 1.4 in (3.6 cm)...
Overview The Black Skirt Tetra (Gymnocorymbus ternetzi), also known as the Black Widow Tetra, is a hardy, deep-bodied tetra with black vertical bars and a dark rear half. Native to slow creeks and streams with overhanging plants in the Paraguay and Guaporé basins of...
Overview The Bloodfin Tetra (Aphyocharax anisitsi) is a silvery tetra with bright red fins. Native to the Paraná River basin in Brazil, Paraguay and Argentina. Grows to about 2.2 in (5.5 cm) standard length. A hardy beginner fish that adapts to a wide range of...
Overview The Bolivian Ram (Mikrogeophagus altispinosus) is a peaceful dwarf cichlid. It is also sold as the Bolivian butterfly cichlid. Native to the upper Rio Madeira basin in Bolivia and Brazil. Grows to about 3.1 in (8 cm) standard length. Usually a better choice...
Overview The Cardinal Tetra (Paracheirodon axelrodi) has a neon-blue stripe above a red lower body that runs the full length of the body. Native to forest streams in the Rio Negro and upper Orinoco basins of Brazil, Colombia and Venezuela. Grows to about 1.4 in (3.5...
Overview The Cherry Barb (Puntius titteya) is a small, peaceful barb. Males turn deep cherry red. Endemic to the wet zone of southwestern Sri Lanka. Grows to about 2 in (5 cm) standard length. An excellent beginner fish. Almost all fish sold are farm-bred. Feeding...
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 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 Colombian Tetra (Hyphessobrycon columbianus) is a robust tetra with a blue-silver body and red fins. It is also sold as the blue-red or Colombian red fin tetra. Known only from the Río Acandí area in northern Colombia, near the Panama border. Grows to...
Overview The Cockatoo Dwarf Cichlid (Apistogramma cacatuoides) is a hardy South American dwarf cichlid named for the male's tall, crest-like dorsal fin. Widespread in the upper Amazon basin, in slow tributaries, backwaters and creeks with leaf litter. Males reach...
Overview The Glowlight Tetra (Hemigrammus erythrozonus) is a small, peaceful tetra with a glowing orange-red stripe. Known only from the Rio Essequibo in Guyana. Grows to about 1.6 in (4 cm) standard length. All fish sold are commercially farmed. An albino form is...
Overview The Frontosa Cichlid (Cyphotilapia frontosa) is a large, blue-and-white barred Lake Tanganyika cichlid with a prominent hump on the forehead. Native to the northern part of Lake Tanganyika. Grows to about 10 in (25.5 cm) standard length. Trade fish are often...
Overview The German Blue Ram (Mikrogeophagus ramirezi), also called Ramirez's dwarf cichlid or butterfly cichlid, is a small, jewel-like dwarf cichlid. Native to the llanos savanna wetlands of the Orinoco basin in Venezuela and Colombia. Grows to about 1.6 in (4 cm)...
Overview The Fairy Cichlid (Neolamprologus brichardi), also known as the Princess of Burundi, is an elegant Lake Tanganyika cichlid with long, white-edged fins. Found along the rocky shores of Burundi, Tanzania and the Democratic Republic of the Congo, mostly 16–82 ft...
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 Rainbow Shark (Epalzeorhynchos frenatum) is a dark-bodied cyprinid with red fins. An albino form is common. Reportedly native to Thailand, Laos and Cambodia, in the Mae Klong, Chao Phraya and Mekong basins. Grows to about 6 in (15 cm) standard length....
Overview The Pindani Cichlid (Pseudotropheus socolofi), also called Eduard's mbuna, is a powder-blue Lake Malawi mbuna. Native to the Mozambique coast of Lake Malawi, between Cobue and Tumbi Point. Grows to about 5 in (11.5 cm) standard length. An albino form is also...
Overview The Pearl Cichlid (Geophagus brasiliensis), also called the pearlscale or mother-of-pearl cichlid, is a robust eartheater with iridescent spangled scales. Native to coastal rivers of eastern and southern Brazil and Uruguay. Grows to about 10 in (25 cm)...
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 Oscar (Astronotus ocellatus) is a large, intelligent South American cichlid, also called the velvet or tiger oscar. Widespread in the Amazon region, usually in slow or still forest waters. Grows to about 14 in (35 cm) standard length. Typically lives...
Overview The Mexican Tetra (Astyanax mexicanus) is best known in its blind cave form, the blind cave tetra. The species ranges from Texas and New Mexico through Mexico to Guatemala. The eyeless form lives only in Mexican caves. Grows to about 3.7 in (9.5 cm) standard...
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...
Overview The Kenyi Cichlid (Pseudotropheus lombardoi, also listed as Maylandia or Metriaclima lombardoi) is a Lake Malawi mbuna. Males are yellow and females are blue with dark bars, which is unusual among mbuna. Found naturally only at the Mbenji Islands and Nkhomo...
Overview The Iridescent Shark (Pangasianodon hypophthalmus) is a large, schooling catfish, not a shark. It was formerly called Pangasius sutchi. Native to the Mekong and Chao Phraya rivers of Southeast Asia. Can reach about 51 in (130 cm) standard length. Sold as...
Overview The Red Shoulder Severum (Heros sp. "Rotkeil") is a severum from Brazil with a red patch behind the gills. Its exact identity is unclear. It is often linked to Heros efasciatus. Severums in general come from slow rivers and floodplain lakes of the Amazon....
Overview The Red-tailed Black Shark (Epalzeorhynchos bicolor) is a velvet-black cyprinid with a bright red tail. Native to central and western Thailand. It is critically rare in the wild. Grows to about 5 in (12.5 cm) standard length. Fish in the trade are farmed....
Overview The White Cloud Mountain Minnow (Tanichthys albonubes) is a small coldwater cyprinid with a gold stripe and red fins. Named for White Cloud Mountain near Guangzhou, China. It is very rare in the wild. Grows to about 1.6 in (4 cm) standard length. Long-finned,...
Overview The X-Ray Tetra (Pristella maxillaris) is a semi-transparent tetra with black, yellow and white fin markings. Native to coastal waters of Venezuela, the Guianas and northern Brazil. Grows to about 1.8 in (4.5 cm) standard length. Commercially bred and one of...
Overview The Trimac Cichlid (Cichlasoma trimaculatum, also listed as Amphilophus trimaculatus) is a large, colorful Central American cichlid. Native to the Pacific slope of western Mexico, Guatemala and El Salvador. Seriously Fish gives a maximum of 16 in (40 cm)....
Overview The Tiger Barb (Puntigrus tetrazona) is a bold, orange-and-black striped barb and a classic aquarium fish. Probably native to central and southern Sumatra. Grows to about 2.4 in (6 cm) standard length. Green, albino and other strains are common. Wild fish are...
Overview The Tinfoil Barb (Barbonymus schwanenfeldii) is a large, shiny silver barb with red fins. Native to Southeast Asia. Found in Thailand, Malaysia, Sumatra and Borneo. Grows to about 14 in (35.5 cm) standard length. It is sold small but grows fast. Feeding An...
Overview The Siamese Algae Eater (Crossocheilus langei and close relatives, long sold as "C. siamensis") is a slim cyprinid with a black side stripe. Found in Borneo, Peninsular Malaysia, southern and western Thailand, and possibly Myanmar. Grows to about 6 in (15 cm)...
Overview The Serpae Tetra (Hyphessobrycon eques), also called the jewel or callistus tetra, is a red tetra with a black shoulder spot. Found through much of the Amazon and the Río Paraguay. Grows to about 1.6 in (4 cm) standard length. Feeding Likely omnivorous....
Overview The Rosy Barb (Pethia conchonius) is a hardy barb. Males turn rose-red when in color. Widespread from Pakistan through India, Nepal and Bangladesh. Grows to about 3.9 in (10 cm) standard length. One of the hardiest small cyprinids. Long-finned and neon forms...