Furry Diary

Not furry, but we like them anyway.

Glowlight Tetra

Hemigrammus erythrozonus

SpeciesShort profile

From South America: the Essequibo River in Guyana (Wikipedia also lists the Courantyne River on the Guyana-Suriname border)123

At a glance the quick version

Length3.3 to 5 cm123
Lifespan2 to 4 years3
Sizesmall
Hardy and great for beginners
Peaceful with most community fish
Glowing orange-red stripe
23

Looks how to spot one

Small scaled characin (tetra) with an adipose fin

A neat, translucent silver tetra with a shining orange-to-red line running from the snout to the base of the tail, as if lit from inside. The front of the dorsal fin carries the same glowing colour, while the other fins are clear to silvery. Mature females are rounder in the belly and a little larger than males.32

Colourssilver bodyiridescent orange to red stripealbino formgolden form32

Personality what they are like

A peaceful, easygoing tetra that makes a good companion for livebearers, danios, rasboras, other tetras and calm bottom dwellers.2

Daily activity how busy a day looks

Moderately active schooling fish; a group cruising together through a planted tank shows off the glowing stripes best.21

Grooming and care the hands-on bits

No grooming needed. Regular partial water changes and a varied diet; colours tend to be brightest in slightly acidic water. All fish in the trade are farm bred.2

Home where they are happiest

Tank of at least 60 cm long (about 68 litres) for a small group. Temperature 24-28 °C, pH about 5.5-7.5 (FishBase gives 6.0-8.0), hardness about 2-15 dGH.213

Food basics what goes in the bowl

Omnivore. Wild fish eat worms, small crustaceans and plant matter; in the aquarium offer flakes and granules plus small live or frozen foods such as bloodworm, Daphnia and brine shrimp.12

Company who they like around

Keep at least 6 together, preferably 10 or more.21

The story where it all began

The glowlight tetra was described by Durbin in 1909 from Guyana's Essequibo River. It has long been a staple of the hobby, and every fish sold today comes from commercial breeding, with many in Europe raised on farms in Eastern Europe.12

Fun facts for the dinner table

  1. 1

    When spawning, the pair rolls over side by side so the female is briefly upside down as the eggs are released.3

  2. 2

    Newly hatched fry look like tiny slivers of glass and only start to show their orange line at around three weeks old.3

  3. 3

    It grows a little larger than both the neon and the cardinal tetra.3

  4. 4

    Its stripe tends to look brighter in soft, slightly acidic water.2

Recognised by the official bits

IUCN Red List
Least Concern (assessed 12 November 2020)1
FishBase
Rated highly commercial in the aquarium trade; noted as a popular aquarium fish1

The care rhythm Furry Diary remembers it for you

A typical home-care rhythm for a Glowlight 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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  1. FishBase species summary: Hemigrammus erythrozonus (Glowlight tetra) fishbase.seused for origin, maximum length, water parameters, natural diet, IUCN status, trade use
  2. Seriously Fish species profile: Hemigrammus erythrozonus seriouslyfish.comused for aquarium size, water parameters, diet, behaviour, group size, sexing, naming
  3. Wikipedia: Glowlight 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.