The Glowlight Tetra, scientifically known as Hemigrammus erythrozonus, is a small, peaceful characin native to the Essequibo River basin in Guyana. It is a long-established favorite in the aquarium hobby, known for its vivid glowing stripe and active schooling behavior.
Adult Glowlight Tetras reach about 1.5 inches (3.5 to 4 cm) in length. Their bodies are translucent silver with a brilliant orange-red stripe running from the snout through the eye and along the body to the base of the tail, resembling a glowing filament. The fins are clear to faintly reddish, and the overall effect is striking under soft, subdued lighting.
A tank of at least 15 to 20 gallons is ideal for a small school. Glowlight Tetras are shoaling fish and should be kept in groups of six or more to bring out their natural activity and color. A planted aquarium with fine gravel or sand substrate, driftwood, and some floating plants to diffuse light best replicates their native habitat.
Water parameters should include a temperature of 74 to 82°F (23 to 28°C), a pH between 5.5 and 7.5, and soft to moderately hard water. They thrive in clean, well-oxygenated water, so regular partial changes and gentle filtration are important.
Feeding Hemigrammus erythrozonus is simple. They are omnivorous and will readily accept high-quality flakes, micro pellets, and small live or frozen foods such as daphnia, brine shrimp, and bloodworms. Variety in their diet enhances color and vitality.
Glowlight Tetras are peaceful and excellent for community aquariums. They mix well with other small, gentle fish such as rasboras, Corydoras, and dwarf gouramis. Avoid housing them with large or aggressive species.
Breeding is possible in captivity and follows typical tetra behavior. They scatter eggs among fine-leaved plants or spawning mops, and no parental care is given. To improve fry survival, adults should be removed after spawning. Fry should be fed infusoria before transitioning to baby brine shrimp.
Hemigrammus erythrozonus (Glowlight Tetra) is a classic, hardy tetra that brings vibrant color, calm schooling behavior, and timeless charm to planted community aquariums.
