Dawn Tetra

About

Start with the awkward part: the fish behind this name and the fish behind this label on a price list are probably not the same animal. Aquarium Glaser, a German wholesaler with one of the largest photo archives in the trade, put it in as many words in December 2024: "The most common 'gold tetra' in the trade comes from Colombia and is generally traded under a false name. It can be found in the trade up and down the country for little money under the name Hyphessobrycon eos (sometimes also as Hemigrammus eos). The species Hyphessobrycon eos actually exists, but it is not kept in the aquarium. H. eos Durbin, 1909, originates from Guyana and there are currently no significant exports from there; we don't even have any photos of H. eos in our huge picture archive." What is imported instead, they say, is Hyphessobrycon saizi from Colombia, Venezuela and Peru, identified as such by Axel Zarske. So a tank of "H. eos" is, on the balance of evidence, a tank of Colombian gold tetras — a fish of "around 2.5- 3 cm" that Glaser calls "a typical companion fish of the Colombian red neon in the wild". The gold itself is worth knowing about, because it is not paint and not a strain. Glaser explains that the metallic sheen "is caused by the increased release of the pigment guanine in the skin, which is caused by infection with worm larvae", that the fish are only intermediate hosts, and that "offspring of golden tetras are invariably normal-colored". Our own golden-tetra entry documents the same mechanism in a different fish, Hemigrammus rodwayi, which is where a keeper looking for that species should actually go. The real Hyphessobrycon eos is a small Guyanese characin described by Marion Durbin in 1909 from, in the Catalog of Fishes' words, a "Creek between Potaro Landing and Kangaruma, Guyana" — the Potaro is the river that goes over Kaieteur Falls, well inside the Guiana Shield. The Catalog lists it as valid and as a Guyana endemic. FishBase records a maximum length of "4.2 cm TL", an IUCN status of "Least Concern (LC); Date assessed: 14 November 2020", and a human-uses line of "Fisheries: commercial; aquarium: commercial" — but its Biology field is empty, and it publishes no temperature, pH or hardness for the species at all. FishBase does explain the name, which is the prettiest thing on the page: "Eos in Greek mythology was the goddess of the dawn. In zoology, her name is generally applied to species that have 'rosy' coloration, sometimes combined with orange or yellowish hues that might be reminiscent of a sunrise." That empty Biology field is why this entry is marked medium confidence rather than high, and why its water numbers deserve a warning label. Nobody publishes aquarium parameters for H. eos. The bands here are derived from where the fish lives — Guiana Shield forest creeks, which are soft, low-conductivity and acid to neutral — and they are deliberately kept modest rather than widened to look easy. They are the genus's soft-water default applied to a Guyanese range, not a figure anyone measured on this species. Everything else in the file follows the same logic: 8-10 in a group, peaceful, mid-water, no threat to plants, and a tank gate set from what a shoal of 4 cm characins needs rather than from a printed recommendation, because there is no printed recommendation.

Care

Buy this one with your eyes open: if the tank is labelled Hyphessobrycon eos and the fish inside are dusted metallic gold, you are almost certainly looking at Hyphessobrycon saizi, the Colombian gold tetra, whose sheen is a parasite response that captive-bred stock does not inherit. Either way the care is the same and undemanding on paper: a group of eight or more, soft to moderately soft water on the acid side of neutral, 24-27 °C, gentle flow, driftwood and leaf litter, a dark substrate and floating cover. Sixty centimetres of base and about 70 litres is the sensible floor for a shoal — no source prints a tank size for this species, so that figure is ours, derived rather than quoted. Peaceful mid-water company only; it is small enough to be eaten by anything cichlid-sized. Safe with plants and, as far as any source says, with snails. Do not expect published water parameters to appear if you go looking: they do not exist for this fish.

Diet

Genus-default micro-omnivore — no wild diet is published for this species. Micro-granules or crushed flake daily, plus live or frozen Daphnia, cyclops, Artemia and bloodworm a few times a week.

Telling males from females

What works for this species, most reliable first.

• Belly depthA hint only · only on well-fed adults, and only as a comparison

  For most tetras, barbs and rasboras this is all there is: a conditioned female is deeper through the belly than a male of the same length.

Also in these lists

Similar species

Same category and the closest water parameters — if this species isn't quite it, start here.

Sold in Lithuania

These Lithuanian shops listed this species in their public catalogue (checked August 8, 2026). Stock moves — ask before you travel.

These links are unpaid: we get nothing for them and ask for nothing.

Frequently asked questions

What tank size does a Dawn Tetra need?

A Dawn Tetra needs an aquarium of at least 70 litres (18.5 US gallons) with a footprint at least 60 cm (23.6 in) long — for this species, swimming length matters as much as raw volume.

What water parameters does a Dawn Tetra need?

Dawn Tetra does best at 22–28 °C (71.6–82.4 °F), pH 5–7.5 and a general hardness of 1–12 °dGH.

What group size does a Dawn Tetra need?

Dawn Tetra is a social species — keep a group of at least 8 so natural behaviour emerges and stress stays low.

Is the Dawn Tetra suitable for beginners?

Dawn Tetra sits in the middle of the difficulty scale — manageable for a careful beginner who has done the reading, but it has specific needs worth researching first.

Sources

• FishBase — Hyphessobrycon eos, Dawn tetra
• Eschmeyer's Catalog of Fishes — Hyphessobrycon eos
• Aquarium Glaser — Hyphessobrycon saizi ("Hyphessobrycon eos") Colombian gold tetra