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 "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 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 The Zebra Danio (Danio rerio) is a hardy, blue-and-gold striped cyprinid, also known as the zebrafish. Native to the Ganges basin and nearby areas of northern India and surrounding countries. Grows to about 2 in (5 cm) standard length. Long-finned and other...
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 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)...