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 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 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 "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 "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 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)...
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...