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 Blue Neon Goby (Stiphodon atropurpureus) is a small stream goby. Males show a vivid blue sheen. Found in short coastal streams in the Philippines, southern China, Taiwan, Japan and Malaysia. Grows to about 2 in (5 cm). Often sold under the wrong name,...
Overview The Bristlenose Pleco (Ancistrus cf. cirrhosus) is the familiar bristlenose catfish sold in most stores. Males grow fleshy bristles on the snout. Grows to about 5 in (12.5 cm) standard length, much smaller than the common pleco. Mass-bred commercially. Its...
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 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 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 "Common Pleco" is a trade name for several large suckermouth catfish, most often the Amazon sailfin catfish (Pterygoplichthys pardalis). Store fish may be a related species or Hypostomus plecostomus. P. pardalis is native to the Amazon basin in Brazil and...
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 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 "Pencilfish" covers several slim Nannostomus species. This profile follows the most common one, the golden pencilfish (Nannostomus beckfordi). N. beckfordi is found in Guyana, Suriname, French Guiana and parts of the Amazon basin. Grows to about 2.6 in (6.5...
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 Peacock Gudgeon (Tateurndina ocellicauda) is a small, colorful sleeper (family Eleotridae), not a true goby. Native to lowland rainforest streams, ponds and rivers of eastern Papua New Guinea. Grows to about 3 in (7.5 cm) standard length. Feeding Accepts...
Overview "Otocinclus" or "oto" covers several small algae-eating catfish. The one sold most often is probably Otocinclus macrospilus. Shipments are often mixed species. O. macrospilus comes from the upper Amazon in Peru, and possibly Colombia and Ecuador. Grows to...
Overview The Sailfin Pleco (Pterygoplichthys gibbiceps) is a large suckermouth catfish with a tall dorsal fin and a leopard-like pattern. Native to the Amazon and Orinoco basins in Brazil, Ecuador, Peru and Venezuela. Can reach around 18–20 in (45–50 cm). Feeding An...