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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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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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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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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