Head and Tail Light Tetra (Hemigrammus ocellifer)

The Head and Tail Light Tetra (Hemigrammus ocellifer) is native to the Guianas (Guyana, Suriname, French Guiana), the Amazon basin, and adjacent river systems in northern South America. It has been a popular aquarium fish since the early 20th century, valued for its distinctive 'beacon' markings and reliable hardiness.

The species name refers to two distinctive iridescent patches: a bright copper-gold spot above and behind the eye (the 'head light') and an equally vivid iridescent spot at the top of the caudal peduncle near the tail base (the 'tail light'). When backlit in an aquarium, these spots appear to glow with warm amber-gold intensity while the rest of the semi-transparent silver body fades to near-invisibility — creating the illusion of free-floating beacons.

Males are slightly slimmer; females rounder. Both reach 4–5 cm. The species is easy to distinguish from similar Hemigrammus species by the dual iridescent spot pattern.

Head and Tail Light Tetras are undemanding, adaptable, and peaceful — qualities that have sustained their popularity over many decades in the hobby. They are easy schooling fish that coexist peacefully with virtually all appropriately sized community species.

Head and Tail Light Tetras adapt to a wide range of conditions: pH 6.0–8.0, hardness 3–20 dGH, and temperatures 22–28°C. Their adaptability makes them among the most forgiving of all tetra species, suitable for a range of community aquarium setups.

A minimum 60-liter aquarium suits a group of 8–10. Dense plantings with moderate open swimming space allow natural schooling behavior. They look most impressive against a dark background where the iridescent beacon spots are highlighted. Moderate current and good filtration maintain water quality.

Feed quality flake food, micro pellets, and supplements of small live or frozen foods: daphnia, baby brine shrimp, and small bloodworms. Undemanding feeders that readily accept standard foods.

Ideal community companions include other tetras, rasboras, corydoras, small catfish, livebearers, gouramis, and peaceful dwarf cichlids. Avoid nippy or aggressive species.

Keep in groups of at least 8 for natural schooling behavior. Weekly water changes of 25–30% maintain water quality.