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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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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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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Harlequin Rasbora

Harlequin Rasbora

Overview The Harlequin Rasbora (Trigonostigma heteromorpha) is a classic schooling fish with a copper body and a black triangle on the rear half. Native to southern Thailand, Peninsular Malaysia, Singapore, Sumatra and Borneo. Grows to about 1.8 in (4.5 cm) standard...

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Glowlight Rasbora

Glowlight Rasbora

Overview The Glowlight Rasbora (Trigonopoma pauciperforatum), also sold as the redline rasbora, is a slim rasbora with a glowing orange-to-gold stripe. Native to Peninsular Malaysia, Singapore, Sumatra and Borneo. Grows to about 2.4 in (6 cm) standard length. Lives in...

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Espes Rasbora

Espes Rasbora

Overview The Espe's Rasbora (Trigonostigma espei), also called the false harlequin or lambchop rasbora, is a small copper-orange rasbora with a black wedge mark. Native to forest streams in southwestern and southeastern Thailand and nearby Cambodia. Grows to about 1.2...

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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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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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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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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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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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