Glowlight Tetra - Hemigrammus erythrozonus Fish Profile & Care Guide
Introduction
The hardy Glowlight tetra (Hemigrammus erythrozonus) is a long-established favourite in the aquarium hobby. First introduced to fishkeepers in the early 1930s, it quickly became one of the more popular small characins as tetras gained favour. Today it is still a regular sight in local fish shops around the world. These small fish are among the hardier tetras available, and the equally bright colouration of both males and females has helped cement their status as a true bread-and-butter species.
Glowlight tetras are peaceful, active shoalers that really come into their own when kept in groups of six or more. In a suitably sized aquarium, they spend most of their time swimming together in the middle to lower regions of the tank, adding constant movement and a warm, glowing splash of colour. They are generally straightforward to care for when provided with stable water conditions and regular maintenance, which makes them a reassuring choice for both beginners and more experienced aquarists.
As classic community fish, Glowlight tetras mix well with a wide range of other small, peaceful species. Suitable tank mates include smaller tetras, Guppies, Platies, Swordtails, Mollies, Corydoras catfish and many of the smaller gouramis. They can also serve as friendly dither fish for dwarf cichlids in larger aquaria, such as Bolivian rams and Kribensis. Larger or more boisterous species should be avoided, as they may bully or prey on Glowlights, leading to stress and health problems.
These little schooling fish appreciate a well-planted aquarium with plenty of cover, especially around the edges, combined with open areas for free swimming. They show beautifully in tanks that incorporate bogwood, fine-leaved plants and, where desired, leaf litter. Although adaptable and able to thrive in typical tap water in many regions, their colouration is often at its best in softer water under subdued lighting, particularly where there is a gentle tannin tint.
The Glowlight tetra is instantly recognisable by its vivid, iridescent orange-red stripe running from the snout to the base of the tail on a silvery body. This stripe is echoed in the front portion of the dorsal fin, while the translucent anal and pelvic fins are delicately edged in white. Combined with their calm nature and constant gentle activity, this glowing pattern makes Glowlight tetras a charming and rewarding addition to the community aquarium.
From our own experience, we have kept Glowlight tetras on and off for more than thirty-five years. They might be labelled a “common” species, but returning to them over the past year has been a reminder that you really cannot beat the classics – a healthy shoal of Glowlights is still every bit as lovely as many of the more recent fashionable fish in the hobby.
Availability
The Glowlight Tetra is avilable from the following marketplace shops.
Fins House
Arkquatica
Photos
Sexual Dimorphism
Adult female Glowlight tetras are typically a little deeper-bodied than males, with a fuller, more rounded belly, especially when they are carrying eggs. Males tend to be slimmer and slightly smaller overall, giving them a more streamlined look. Colouration is very similar between the sexes, so body shape is usually the most reliable way to tell them apart in a mature group.
Quick Facts
| Scientific Name | Hemigrammus erythrozonus |
|---|---|
| Year Described | 1909 |
| Other Names | Glowlights, Fire Neon Tetra |
| Kingdom | Animalia |
| Classification | Actinopterygii |
| Order | Characiformes |
| Family | Characidae |
| Genus | Hemigrammus |
| Origins | Guyana |
| Approx Max Size | 5 cm |
| Temperament | Peaceful |
| Aquarium Level | Middle |
| Difficulty | Beginner - Intermediate |
| Shoaling | Yes |
| Best kept as | Groups 6+ |
| Diet & Feeding | Omnivore |
| Reproduction | Egg-Scatterer |
| Average Lifespan | Up to 5 Years |
Water Parameters
| Water Type | Freshwater |
|---|---|
| pH | 5.5 - 7.5 |
| GH | 3 - 15 |
| ℉ | 74 - 82 |
|---|---|
| ℃ | 23 - 28 |
Natural Habitat
In the wild, the Glowlight tetra is primarily known from the Essequibo river basin in Guyana, with records from tributaries such as the Potaro and Mazaruni, and it has also been reported from nearby drainages. It typically inhabits small, forested side streams and creeks that branch off the main river channels. These quiet waters are often stained a dark tea-brown by tannins released from leaf litter and other decaying plant material. They are usually soft and acidic, with subdued light filtered through overhanging vegetation, creating the dim, sheltered conditions in which this species naturally thrives.
Breeding
Glowlight tetras are egg scatterers and will occasionally spawn in a peaceful community aquarium, although the eggs and fry are rarely seen because the adults quickly eat them. For a realistic chance of rearing a batch, it is best to use a separate, dimly lit breeding tank with soft, slightly acidic water, fine-leaved plants or spawning mops, and a gentle sponge filter.
Condition a small group or a carefully selected pair on plenty of live and frozen foods, then introduce them to the breeding tank in the evening. Spawning usually takes place at first light, with the fish scattering small, adhesive eggs among the plants or over the substrate. Once eggs are visible, the adults should be removed so they do not eat them.
The eggs typically hatch within a couple of days, depending on temperature. The tiny fry will cling to surfaces at first, then begin to swim freely and can be started on infusoria, commercial liquid fry foods or very fine powdered fry foods. As they grow, they can move on to newly hatched brine shrimp and finely crushed flake. Good water quality, gentle filtration and regular small feeds are essential for raising a strong, even group of youngsters.
Diet & Feeding
Glowlight tetras are omnivores and do best on a varied diet offered in small portions. A good quality, finely crushed flake or micro pellet can form the staple, as long as it is small enough for them to eat comfortably. Although not strictly necessary, this can be topped up regularly with live or frozen foods such as baby brine shrimp, daphnia and mosquito larvae, which help bring out their colour and encourage natural, lively feeding behaviour.
In the aquarium, they usually feed in the middle of the water column, picking at food as it drifts past, and will also take some items from the surface. Only offer as much as they can comfortably eat within a few minutes, because overfeeding quickly leads to uneaten food, poor water quality and digestive issues. Several small feeds spread through the day suit them far better than one large meal and help keep your shoal active, healthy and glowing.
Videos
Other Tetras
02/10/2025
These little fish are hardy as nails, perfect for anyone new to the hobby or looking for something with little demands!
Published: 15 Sep 2020
Last Updated: 04 Dec 2025