Head and Tail Light Tetra (Beacon Fish)

Characteristics, Origin, and Helpful Information

Hemigrammus ocellifer - Head and Tail Light Tetra
Chen Heng-Jou

Best known for its coppery spots that look like taillights, the head, and tail light tetra hails from the freshwater river and streams in South America. A peaceful schooling fish, this tetra species does not need a large tank, it just wants plenty of open swimming space and subdued mood lighting to keep it content.

Breed Overview

Common Names: Beacon fish, beacon tetra, head and tail light tetra

Scientific Name: Hemigrammus ocellifer

Adult Size: 2 inches

Life Expectancy: 2 inches


Family Characidae
Origin Argentina, Brazil, French Guiana, Guyana, Peru, and Suriname
Social Peaceful, schooling fish
Tank Level Mid-dweller
Minimum Tank Size 15 gallon
Diet Omnivore
Breeding Egglayer
Care Easy
pH 6 to 8
Hardiness 5 to 19 dGH
Temperature 72 to 79 F (22 to 26 C)

Origin and Distribution

Hemigrammus ocellifer originates from South America, where it can be found in numerous locations along the Amazon and Orinoco river basin, as well as along the coast of Guyana. Favoring slow-moving rivers and streams, it can be found in Argentina, Brazil, French Guiana, Guyana, Peru, and Suriname. Wild-caught specimens are rarely sold in the trade, as most are now captive-bred for commercial sale.

The scientific name comes from the Greek Hemmigrammus meaning "half line," which refers to an incomplete lateral line, and ocellifer, which means "eye bearing," a reference to the reflective spots or "eyes" on the head and tail of the fish. First described as Tetragonopterus ocellifer, this species was later moved to the Hemigrammus genus. 

Colors and Markings

Its body is iridescent silver in color and, like many other tetras, is oval in shape. Seen from above, the body is compressed, with the males being thinner than their female counterparts. The upper rim of the eye is edged in brilliant red, similar to the red eye tetra. The fins are translucent, and on some specimens, a fine black line runs from mid-body to the spot on the tail fin. Adults reach a length of approximately two inches (5 centimeters).

Head and tail light tetras are named for two coppery colored reflective spots that resemble tail lights. One is located at the base of the tail and the other is near the head, next to the gill cover. These reflective patches are coupled with a black spot. The inheritance of this spotting pattern is of particular interest, since it probably serves as an eyespot, mimicking the red color of the iris of the eye. 

Hemigrammus ocellifer falsus, has been named as a possible subspecies. It is more slender and has the “taillight” spot, but lacks the spot behind the gill cover.


Head and tail light tetras do best in schools of a half dozen or more and can be kept with other peaceful fish, particularly other members of the tetra family. Barbs, danios, rasboras, and other small-to-medium- sized peaceful fish are also good companions. Small loaches, catfish, dwarf cichlids, and smaller gouramis are also suitable.

Avoid fish that are large enough to eat them. Some owners report that their head and tail light tetras will nip the fins of slow-moving long-finned species such as angelfish and bettas.

Head and Tail Light Tetra Habitat and Care

Head and tail light tetras are generally undemanding in habitat. But, if you really want to see this little tetra shine, you could set up a biotope tank with real or artificial plants. Floating or tall plants that reach the top of the tank to provide shade are particularly desirable, as this fish prefers shady spots. 

Use river sand or a darker substrate, which will add to the subdued décor. Add a few driftwood branches and twisted roots. A few handfuls of dried leaves (beech or oak leaves are suitable) would complete the natural feel. Allow the wood and leaves to stain the water the color of weak tea, removing old leaves and replacing them every few weeks so they don’t rot and foul the water. A small net bag filled with aquarium-safe peat can be added to the filter to aid in the simulation of black water conditions. 

Open swimming space in the middle will complete the ideal tank arrangement.

Head and Tail Light Tetra Diet

Omnivorous in nature, the head and tail light tetra will eat most foods, but will not nibble on the live plants. Provide a good variety of flake foods along with freeze-dried or frozen live foods, such as brine shrimp, bloodworms, and small insects. They will eat fine pelleted food as well. Live foods should be used when conditioning before breeding.

Sexual Differences

Females are rounder and plumper than males, particularly when viewed from above. The swim bladder in the male is pointed and more visible than the rounded swim bladder in the female. Since this fish is translucent, it is possible to view the swim bladder by using a strong light.

Breeding of Head and Tail Light Tetra 

An egg-layer, this species of tetra is relatively easy to breed. The tank should be fitted with plenty of plants for the breeder pair to lay their eggs on. Lighting should be dim. Water in the aquarium should be soft, temperature 80 F (26 C), and pH slightly acidic in the range of 6.0 to 6.5.

Condition the breeder pair with live foods for a week or two. Bloodworms and brine shrimp are good choices, and frozen may be used if live is not available. As the spawning time approaches, the belly of the female will swell noticeably with eggs. Spawning typically occurs in the morning, with up to 1,000 eggs being laid over the course of the day.

Once the eggs are laid, remove the parents promptly, as they will consume the eggs and young fry. The eggs will hatch in 24 hours, and the fry becomes free-swimming within another two days. During this time, make sure the lighting is very subdued. If the room is brightly lit, it is wise to drape the tank to reduce the light. Feed the fry commercially prepared fry food, egg yolk, or paramecium. Within a few days, freshly hatched brine shrimp can also be fed to the fry.

More Pet Fish Breeds and Further Research

If head and tail light tetras appeal to you, and you are interested in some compatible fish for your aquarium, read up on:

Check out additional fish breed profiles for more information on other freshwater fish.