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 Clown Knifefish (Chitala ornata) is a large, nocturnal predator with a row of black spots along its knife-shaped body. Native to the Mekong, Chao Phraya and Mae Klong basins of Thailand, Laos, Cambodia and Vietnam. Can reach about 39 in (100 cm), far too...
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 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...
Overview The Scarlet Badis (Dario dario) is one of the smallest percoid fish. Males are bright red with blue bars. Found in tributaries of the Brahmaputra in West Bengal and Assam, India. Grows to about 0.8 in (2 cm) standard length. A popular nano fish. Feeding A...