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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Blue Neon Goby

Blue Neon Goby

Overview The Blue Neon Goby (Stiphodon atropurpureus) is a small stream goby. Males show a vivid blue sheen. Found in short coastal streams in the Philippines, southern China, Taiwan, Japan and Malaysia. Grows to about 2 in (5 cm). Often sold under the wrong name,...

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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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Cherry Barb

Cherry Barb

Overview The Cherry Barb (Puntius titteya) is a small, peaceful barb. Males turn deep cherry red. Endemic to the wet zone of southwestern Sri Lanka. Grows to about 2 in (5 cm) standard length. An excellent beginner fish. Almost all fish sold are farm-bred. Feeding...

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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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Peacock Gudgeon

Peacock Gudgeon

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...

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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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Iridescent Shark

Iridescent Shark

Overview The Iridescent Shark (Pangasianodon hypophthalmus) is a large, schooling catfish, not a shark. It was formerly called Pangasius sutchi. Native to the Mekong and Chao Phraya rivers of Southeast Asia. Can reach about 51 in (130 cm) standard length. Sold as...

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Tinfoil Barb

Tinfoil Barb

Overview The Tinfoil Barb (Barbonymus schwanenfeldii) is a large, shiny silver barb with red fins. Native to Southeast Asia. Found in Thailand, Malaysia, Sumatra and Borneo. Grows to about 14 in (35.5 cm) standard length. It is sold small but grows fast. Feeding An...

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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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Rosy Barb

Rosy Barb

Overview The Rosy Barb (Pethia conchonius) is a hardy barb. Males turn rose-red when in color. Widespread from Pakistan through India, Nepal and Bangladesh. Grows to about 3.9 in (10 cm) standard length. One of the hardiest small cyprinids. Long-finned and neon forms...

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