At a glance the quick version
Looks how to spot one
Small scaled characin (tetra) with an adipose fin
A slender little tetra marked by two stripes running side by side along the body, a bright white line sitting on top of a wide black band. The top of the eye carries two thin bands of red over yellow. Females are a little larger and deeper in the body than males. A 'diamond' or 'brilliant' variety lacks the white line but has extra shiny scales around the head.32
Personality what they are like
A calm, gentle tetra that mixes well with other small, peaceful fish. It feels most confident and shows its best colour when kept in a decent group alongside other schooling species.2
Daily activity how busy a day looks
Swims mostly in the middle and upper water layers; appreciates open swimming space next to planted cover.1
Grooming and care the hands-on bits
No grooming needed. Keep water clean and stable with regular partial changes; captive-bred fish cope well with mature tap water.32
Home where they are happiest
Tank of at least 60-80 cm long (Seriously Fish suggests an 80 x 30 cm base, about 72 litres). Temperature 23-27 °C (Seriously Fish gives 20-28 °C), pH about 5.0-7.5, soft to moderately hard water up to about 12-15 dGH.12
Food basics what goes in the bowl
Omnivore. Wild fish eat worms, small crustaceans and plant matter; in the aquarium offer a mix of good dry food with live or frozen bloodworm, mosquito larvae, Daphnia or Moina.123
Company who they like around
Keep in a group: FishBase says 5 or more, Seriously Fish recommends a mixed-sex group of at least 8-10.12
The story where it all began
Jacques Géry described the species in 1961 and named it after the American pet-book publisher Herbert R. Axelrod, whose Tropical Fish Hobbyist magazine carried the description. It has been a fixture of the hobby ever since and is bred commercially in several countries rather than collected from the wild.32
Fun facts for the dinner table
- 1
Its scientific name honours Herbert R. Axelrod, the publisher behind Tropical Fish Hobbyist magazine.3
- 2
Look closely and you will see a tiny red-over-yellow band across the top of each eye.3
- 3
In 2023 a black neon tetra 'playing' a Nintendo Switch through motion-tracking software accidentally bought something from the eShop on its owner's account.3
- 4
Eggs scattered in open water hatch in about 24 to 30 hours.1
Recognised by the official bits
- IUCN Red List
- Least Concern (assessed 7 November 2018)1
- FishBase
- Rated highly commercial in the aquarium trade1
The care rhythm a typical week and year
A typical home-care rhythm for a Black Neon Tetra. A starting point, not a vet's advice.
- 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
Owner questions the things everyone asks
How often should I feed my Black Neon Tetra?
Feed small amounts once or twice a day. Furry Diary's starting plan suggests feeding daily, and it's best to give only what they can eat in a couple of minutes.12 Pet Wiki plan
What does a Black Neon Tetra eat, and what should it never eat?
They are omnivores and enjoy a mix of good dry food with live or frozen treats like bloodworm and daphnia. Avoid feeding them anything large or unsuitable for small fish, and never give medicines without a vet's advice.123
How much space does a Black Neon Tetra need?
A tank at least 60-80 cm long is recommended, with a base of about 80 x 30 cm (roughly 72 litres). This gives them room to swim in the middle and upper water layers.12
What temperature, light or water does a Black Neon Tetra need?
Keep water temperature between 23-27 °C, pH around 5.0-7.5, and soft to moderately hard water up to about 12-15 dGH. They appreciate planted cover and open swimming space.12
How often should I clean a Black Neon Tetra's home?
Furry Diary's starting plan suggests a weekly 25% water change, along with weekly glass cleaning and water testing. Rinse the filter monthly in old tank water, never tap water.32 Pet Wiki plan
Can a Black Neon Tetra live with others?
Yes, they are calm and gentle, mixing well with other small, peaceful fish. Keep them in a group of at least 5, and ideally 8-10, to help them feel confident and show their best colour.21
How long does a Black Neon Tetra live?
With good care, they can live for several years, but exact lifespan varies. Ask a good breeder or exotic-pet vet for more specific information.
Can I handle a Black Neon Tetra?
It's best not to handle them, as they are delicate fish. Use a soft net if you need to move them, and always keep their water clean and stable.32
Written from the sources on this page, a few checked guides (VCA, ASPCA, RSPCA) and Pet Wiki's own starting care plan. A friendly guide, not a vet's advice.
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Every fact on this page has a numbered source. Spotted an error? support@petwiki.app.
- FishBase species summary: Hyphessobrycon herbertaxelrodi (Black neon tetra) fishbase.seused for origin, maximum length, water parameters, natural diet, IUCN status, trade use
- Seriously Fish species profile: Hyphessobrycon herbertaxelrodi seriouslyfish.comused for aquarium size, water parameters, diet, behaviour, group size, sexing, naming
- Wikipedia: Black Neon Tetra en.wikipedia.orgused for other names, appearance, lifespan, history, fun facts
Checked 2026-09-30. Text is written in our own words from these sources.