Not furry, but we like them anyway.
Red Phantom Tetra
Megalamphodus sweglesi
Also called Hyphessobrycon sweglesi (former name), Megalamphodus sweglesi
From South America: upper and middle Río Orinoco basin in Colombia and Venezuela, including the Meta, Arauca, Apure and Cinaruco tributaries123
At a glance the quick version
Looks how to spot one
Small, slender scaled characin
A slim little tetra whose colour ranges from a see-through silvery form to a rich red one, depending on where the fish come from. There is a dark spot just behind the head, and females carry a dark dorsal fin edged in cream. Mature males grow longer dorsal and anal fins.13
Personality what they are like
A calm, sociable tetra that gets along well with other small, gentle fish. Males hold small displays with each other within the group.1
Daily activity how busy a day looks
Moves around actively in the middle water layers and appreciates both open water and plant cover.13
Grooming and care the hands-on bits
Undemanding with stable, clean water and a varied diet; regular partial water changes help keep it in top colour.1
Home where they are happiest
Tank with a base of at least about 80 x 30 cm (around 72 litres); FishBase gives 60 cm as a minimum length. Temperature from about 20 to 28 °C (FishBase lists 20 to 23 °C), pH roughly 4.5 to 7.5, soft water (1 to 12 dGH). In nature it lives among submerged plants in clear or tea-stained water.123
Food basics what goes in the bowl
Omnivore. Accepts dried foods, but does best with a mix that includes small live and frozen foods such as bloodworm and Daphnia.12
Company who they like around
Shoaling fish: at least 5 individuals, preferably a group of 8 to 10 or more, with similar-sized peaceful species.12
The story where it all began
French ichthyologist Jacques Géry described the species in 1961, naming it after Kyle Swegles, a tropical fish dealer who collected the first specimens in the upper Orinoco. It has since been shifted between the genera Megalamphodus and Hyphessobrycon and is currently placed in Megalamphodus.213
Fun facts for the dinner table
- 1
Its scientific name honours Kyle Swegles, the fish trader who collected the type specimens.2
- 2
At least three colour forms are known, from almost transparent silvery fish to strongly red ones.3
- 3
Unlike some red fish that fade in aquariums, its red colouring tends to last in captivity.1
- 4
Females are easy to spot by the dark, cream-edged stripe on the dorsal fin.3
Recognised by the official bits
- IUCN Red List
- Least Concern (assessed 16 November 2020)2
- FishBase
- Listed as a commercial aquarium species2
The care rhythm Furry Diary remembers it for you
A typical home-care rhythm for a Red Phantom Tetra. It is our own starting plan, not a vet's advice, and you can change every line in the app.
- FeedingSmall amounts once or twice a dayevery day
- Temperature checkevery day
- Water changeAbout 25% of the waterevery week
- Water testevery week
- Glass cleanevery week
- Filter rinseRinse in old tank water, never tap waterevery month
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Where this comes from
Every breed page shows where each fact comes from. If we got something wrong, sorry, we are pet people, not a science magazine. Tell us at [email protected] and we will fix it.
- Seriously Fish: Hyphessobrycon sweglesi seriouslyfish.comused for range, size, care parameters, diet, behaviour, colour forms, history
- FishBase: Megalamphodus sweglesi fishbase.seused for distribution, max length, water parameters, IUCN status, etymology
- Wikipedia: Red phantom tetra en.wikipedia.orgused for appearance, habitat, colour forms, taxonomy
Checked 2026-09-30. Text is written in our own words from these sources.