Freshwater Aquarist

Popular Fish Species for your Aquarium

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.

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Bristlenose Pleco

Bristlenose Pleco

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...

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Clown Loach

Clown Loach

Overview The Clown Loach (Chromobotia macracanthus) is a bright orange loach with black bands. It is very popular, but often bought without knowing how big it gets. Native to rivers of Borneo and Sumatra in Indonesia. Can reach about 16 in (40 cm), though it grows...

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Common Pleco

Common Pleco

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...

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Dwarf Snakehead

Dwarf Snakehead

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...

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Pencilfish

Pencilfish

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...

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Otocinclus Catfish

Otocinclus Catfish

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...

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Kuhli Loach

Kuhli Loach

Overview The Kuhli Loach is a slender, eel-like loach with orange and dark bands. It is sold as Pangio kuhlii. Most trade fish are actually Pangio semicincta from Peninsular Malaysia, Sumatra and Borneo. True P. kuhlii is from Java and is rarely exported. Grows to...

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Zebra Loach

Zebra Loach

Overview The Zebra Loach (Botia striata) is a small botiid with fine yellow and dark stripes. Native to the Western Ghats region of southern India, described from the Tunga River. Grows to about 3.5 in (9 cm) standard length. Probably the best Botia for general...

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Yoyo Loach

Yoyo Loach

Overview The Yoyo Loach is usually sold as Botia almorhae. Its pale body has dark markings that can look like the letters "YOYO." Many trade fish may be B. lohachata or related species. The true appearance of B. almorhae is unclear. Native to northern India and Nepal....

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Sailfin Pleco

Sailfin Pleco

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...

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