The Hemigrammus erythrozonus, better known as the Glowlight tetra, is a small schooling fish much loved for its fluorescent orange stripe along its body. Peaceful, robust and easy to maintain, it is ideal for community planted aquariums, from beginners to advanced.

Origin & habitat

This species is native to South America, mainly the Essequibo basin in Guyana. It is found in rivers and small forested streams, where the water is often soft, slightly acidic and sometimes amber-coloured due to the presence of dead leaves, roots and submerged wood.

Description & sexual dimorphism

• Adult size: 3.5-4.5 cm
• Lifespan: 4 to 5 years in good conditions
• Body: fusiform, semi-transparent, slightly silvery
• Light band: bright neon orange/copper line running from the eye to the base of the caudal fin
• Fins: translucent to slightly orange, especially the dorsal and anal fins

Sexual dimorphism is discrete: females are slightly more plump, especially during the spawning period, while males appear slimmer and sometimes a little more colourful.

Recommended water parameters

• Temperature: 23-27°C
• pH: 5.5-7.5 (slightly acidic to neutral)
• Hardness: 2-12 °dGH (soft to moderately hard water)
• Filtration: gentle but effective, clean, well-oxygenated water

Like many small characids, it appreciates stable parameters and regular water changes (20-30% per week) to stay healthy and retain intense colours.

Aquarium maintenance

• Minimum recommended volume: from 80-100 L, with a good front length (60-80 cm)
• Decor: densely planted tank, roots, driftwood, shaded areas and hiding places
• Substrate: preferably dark, to bring out the light band
• Swimming zone: mainly the middle zone
• Lighting: moderate, possibly subdued by floating plants

A community-type planted aquarium with a few tannins (catappa leaves, alder fruit) reproduces its biotope well and perfectly enhances its "glowlight" appearance.

Behaviour & cohabitation

Hemigrammus erythrozonus is a gregarious, calm and peaceful fish. It should be kept in shoals of at least 8 to 10 individuals, ideally more, to limit stress and achieve a beautiful visual effect.

• Character: peaceful, non-aggressive, spends most of its time swimming in groups in open water.
• Ideal mates: other small tetras, rasboras, calm danios, corydoras, small loricarids, dwarf gouramis, robust shrimps.
• Avoid: large cichlids, very lively or aggressive fish, species that might consider it as prey.

In large groups, they are confident, active and form a bright school that is very pleasant to watch.

Diet

Omnivorous with a tendency to micropredation, the glowlight tetra readily accepts a varied diet:

• Dry food: fine flakes, quality micro-granules suitable for small tropical fish.
• Live/frozen supplements: artemia, daphnia, cyclops, mosquito larvae, very popular and beneficial for colour.
• Plant-based: foods containing plant extracts or spirulina, for a good nutritional balance.

Distribute 2-3 small meals a day, consumed in a few minutes, to avoid pollution and maintain good water quality.

Reproduction in an aquarium

Reproduction is possible for motivated aquarists. It is a free-laying fish that spreads its eggs among the fine vegetation.

• Dedicated breeding tank (20-40 L), soft water (GH < 5), slightly acidic pH, subdued lighting.
• Substrate: plants with fine leaves (Java moss, Ceratophyllum) or spawning mops, or even a bottom grid.
• Introduce a small group or pair well fed with live prey to stimulate reproduction.
• Remove adults after spawning, as they may consume the eggs.
• Eggs hatch in 24-36 h; feed fry with infusoria, then artemia nauplia.

Aquabota tips

• Maintain a large shoal to reduce stress and obtain a very aesthetic light cloud effect.
• A dark background and moderate lighting will make the copper band stand out.
• Stable parameters, clean water with low nitrate content = more resistant fish and brighter colours.
• Perfect for keeping with other small, calm fish in a planted, softly lit tank.

Quick facts

• Zoological Name: Hemigrammus erythrozonus
• Common names: glowlight tetra, bright copper tetra
• Origin: Guyana (Essequibo basin)
• Adult size: 3.5-4.5 cm
• Swimming area: middle of the tank
• Temperature: 23-27°C
• pH: 5.5-7.5
• Hardness: 2-12 °dGH
• Behaviour: gregarious, very peaceful
• Difficulty level: easy to intermediate

Shipping & Delivery of live fish

Our Hemigrammus erythrozonus are prepared with the greatest care in our Aquabota fishroom. Each fish is selected, acclimatised and observed before shipping to ensure optimum health.

• Packaging: oxygenated bags, insulated in crates specially designed for transporting live fish.
• Transport: express delivery via suitable carriers, keeping time spent in transit to a minimum.
• Temperature: use of heaters or ice packs depending on the season to maintain the right temperature.
• Arrival: an Aquabota acclimatisation guide will help you to integrate your new residents in the best possible conditions.

If you have any questions before or after placing your order, our Aquabota team will be happy to advise you on the choice of fish, their compatibility and the ideal parameters for your aquarium.