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 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 Harlequin Rasbora (Trigonostigma heteromorpha) is a classic schooling fish with a copper body and a black triangle on the rear half. Native to southern Thailand, Peninsular Malaysia, Singapore, Sumatra and Borneo. Grows to about 1.8 in (4.5 cm) standard...
Overview The Glowlight Rasbora (Trigonopoma pauciperforatum), also sold as the redline rasbora, is a slim rasbora with a glowing orange-to-gold stripe. Native to Peninsular Malaysia, Singapore, Sumatra and Borneo. Grows to about 2.4 in (6 cm) standard length. Lives in...
Overview The Espe's Rasbora (Trigonostigma espei), also called the false harlequin or lambchop rasbora, is a small copper-orange rasbora with a black wedge mark. Native to forest streams in southwestern and southeastern Thailand and nearby Cambodia. Grows to about 1.2...
Overview "Dwarf Snakehead" usually refers to Channa gachua. The name is also used for other small snakeheads such as C. bleheri and C. andrao. C. gachua has a huge range from Iran to Taiwan and Bali. It is probably a complex of several similar species. Grows to about...
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 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...