Furry Diary

Not furry, but we like them anyway.

Rosy Tetra

Megalamphodus rosaceus

Also called Hyphessobrycon rosaceus (former name), Hyphessobrycon ornatus (historical synonym)

SpeciesShort profile

From South America: Guyana and Suriname (Essequibo, Corantijn/Courantyne and Suriname river basins), with Seriously Fish also listing Brazil123

At a glance the quick version

Length3.4 to 4 cm231
Sizesmall
Very peaceful community fish
Elegant long fins on mature males
Mixes well with many small South American species
13

Looks how to spot one

Small, deep-bodied scaled characin

A deep-bodied little tetra with a pinkish blush on the lower flanks and fins. Mature males are larger, slimmer and more colourful, with long, flowing dorsal and anal fins. It looks much like the closely related bentosi tetra but has no dark spot behind the gill cover.13

Coloursrosy pink flanksred-tinted fins31

Personality what they are like

Calm and friendly toward other fish. A group settles into a relaxed shoal, with males flaring their fins at each other in harmless displays.1

Daily activity how busy a day looks

Swims steadily in mid-water; enjoys open space next to dense planting.13

Grooming and care the hands-on bits

Straightforward care: stable soft to medium water, regular partial water changes and a varied diet. Colours look richest in slightly acidic water.1

Home where they are happiest

Tank of at least about 60 x 38 x 30 cm (around 68 litres) for a small group. Temperature 24 to 28 °C, pH about 5.5 to 7.5, hardness up to about 12 to 20 dGH. In nature it prefers clear, slow streams with lots of aquatic plants.123

Food basics what goes in the bowl

Eats small invertebrates in the wild. In the aquarium offer good flakes or granules plus small live and frozen foods.1

Company who they like around

Shoaling fish: at least 6, ideally 10 or more, kept with other peaceful tetras, rasboras, barbs or dwarf cichlids.1

The story where it all began

Marion Durbin Ellis described the rosy tetra in 1909 from fish collected at Gluck Island in the Essequibo River, Guyana. It became a popular aquarium fish and was moved to the genus Megalamphodus in 2024.312

Fun facts for the dinner table

  1. 1

    Its type locality is Gluck Island in the Essequibo River in Guyana.3

  2. 2

    It is easily confused with the bentosi tetra, but lacks that species' dark shoulder mark.1

  3. 3

    Its eggs hatch in roughly 24 to 36 hours.1

  4. 4

    Males grow noticeably longer dorsal and anal fins than females.1

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 Rosy Tetra. It is our own starting plan, not a vet's advice, and you can change every line in the app.

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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.

  1. Seriously Fish: Megalamphodus rosaceus seriouslyfish.comused for range, size, care parameters, diet, behaviour, breeding
  2. FishBase: Megalamphodus rosaceus fishbase.seused for distribution, length, water parameters, IUCN status
  3. Wikipedia: Rosy tetra en.wikipedia.orgused for history, type locality, appearance, synonyms

Checked 2026-09-30. Text is written in our own words from these sources.