At a glance the quick version
Looks how to spot one
Small, deep-bodied scaled characin
A compact, almost diamond-shaped tetra in smoky grey to near-black tones. Behind the gill cover sits a dark shoulder patch framed by a shimmering silver edge. Males carry large, fully black fins, while females show red on the pelvic, anal and adipose fins. Breeders have also produced a long-finned form.13
Personality what they are like
Gentle and easy-going with other fish. Males like to show off to each other by spreading their big black fins, which is all display and part of the charm of a well-sized group.13
Daily activity how busy a day looks
Active mid-water swimmer that benefits from open swimming space alongside planted areas.1
Grooming and care the hands-on bits
Hardy and adaptable once settled. Regular partial water changes and a varied diet keep the colours at their best.1
Home where they are happiest
Tank with a base of at least about 80 x 30 cm (around 72 litres), although FishBase gives 60 cm as a minimum length. Temperature roughly 20 to 28 °C, pH about 5.0 to 7.5, soft to moderately hard water (1 to 12 dGH). Plants, wood and subdued light suit it well.12
Food basics what goes in the bowl
Omnivore. In the wild it eats small invertebrates, worms and some algae. In the aquarium give good dried foods plus small live or frozen foods such as bloodworm, mosquito larvae, Daphnia and Moina.12
Company who they like around
Shoaling fish: keep at least 5 together, ideally 8 to 10 or more, with similar-sized peaceful tankmates.12
The story where it all began
Carl H. Eigenmann described the species scientifically in 1915 from material collected at Cáceres in Mato Grosso, Brazil. The black form reached European aquarists through German importers in the 1930s, and today nearly all fish in the hobby are bred in captivity. It was later moved from Hyphessobrycon to the genus Megalamphodus.31
Fun facts for the dinner table
- 1
Wild populations differ by region: the black form comes from the Guaporé basin, while fish from the southern Pantanal around 700 km away are naturally reddish.3
- 2
Males and females look so different that they can be told apart at a glance by fin colour: black for males, red-tinged for females.1
- 3
In the wild it mixes with other small species in shoals and forages among plants near the shore.3
- 4
A long-finned variety has been developed by captive breeders.3
Recognised by the official bits
- IUCN Red List
- Least Concern (assessed 4 March 2021)2
- FishBase
- Listed as a commercial aquarium species2
The care rhythm Furry Diary remembers it for you
A typical home-care rhythm for a Black 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
You might also like
Red Phantom Tetra
Rosy TetraLike what we are building? Buy us a coffee.
The breed atlas is free for everyone, with a source on every fact, and it will never show ads. If it helped you, a small tip keeps the research going. Any amount is lovely, and no is a perfectly fine answer too.
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 support@furrydiary.app and we will fix it.
- Seriously Fish: Megalamphodus megalopterus seriouslyfish.comused for range, size, care parameters, diet, behaviour, dimorphism
- FishBase: Megalamphodus megalopterus fishbase.seused for distribution, max length, water parameters, IUCN status, diet
- Wikipedia: Black phantom tetra en.wikipedia.orgused for history, colour forms, appearance, fun facts
Checked 2026-09-30. Text is written in our own words from these sources.