Back to top

Head and Taillight Tetra – Hemigrammus ocellifer


Head and Taillight Tetra

Tetras are amongst the most popular aquarium fishes. There are probably more than 150 distinct species of tetra from which the aquarist may choose and this includes a large number of visually stunning fishes that are bound to enhance any home aquarium.

Is the Head and Taillight Tetra a good community fish? The Head and Taillight Tetra could be an excellent community fish and gets on with most species and is most peaceful, bordering on timid. The Head and Taillight Tetra is a rhomboid Tetra in shape. The Head and Taillight Tetra is quite easier to sex than most Tetras because the swim bladder of the male is pointed whilst that of the female is rounded when viewed in strong light.

Key Facts

CategoryKey Facts
Common name(s)Head and Taillight Tetra – also known as:
Beacon Fish
Beacon Tetra
Scientific nameHemigrammus ocellifer
FamilyCharacidae
Originate fromGuyana, Suriname, French Guiana, and the Amazon Basin of Brazil and Peru in South America
Care requiredEasy to care for and hugely popular
TemperamentPlacid, shoaling fish
Colour & FormSilver, rhomboid, sem-translucent body with red arc over eye and yellow and black patches behind gill plate and on caudal peduncle
LifespanUp to 5 years
Adult size2.0 inches
DietOmnivorous – eat aquatic insect larvae in nature
Aquarium size24 inches in length or greater
Compatible withMost other Tetras, Barbs, Danios, Guppies and other livebearers, dwarf cichlids, smaller Gouramis, catfish and loaches
Avoid keeping withLarge and/or aggressive species
BreedingEasy if you put the fish in the right environment.
Water temp72- 80 Fahrenheit
Water pH6.0 to 8.0
Water hardness (dGH or dH)5 to 19 dGH

Origins of the Head and Taillight Tetra

Tetras, as a “family” of fishes belonging to the biological family Characidae are found in nature in Africa, Central America and South America.

The Head and Taillight Tetra is found in the rivers of Guyana, Suriname, French Guiana, and the Amazon Basin of Brazil and Peru in South America. The vast majority of Head and Taillight Tetras available to aquarists are captive-bred and the species is becoming increasingly popular.

Characteristics of the Head and Taillight Tetra

As you can see, the Head and Taillight Tetra is characterized by its beautifully coloured silver body which is semi-translucent with a rich yellow to orange coloured arc over the eye, plus an orange/yellow and a black patch behind the gill plate and another orange/yellow and a black patch on the caudal peduncle. The fins are all more-or-less clear (hyaline) but may have white tips.

The Head and Taillight Tetra will grow to up to 2 inches in the aquarium and live for around five years.

Head and Taillight Tetras prefer fairly neutral or acidic water with a pH of 6.0 to 8.0 with a temperature range between 72 and 80 degrees Fahrenheit and up to 5 to 19 dGH.

It is generally recommended that Head and Taillight Tetras are kept in neutrally-filtered aquarium and either as a single species or with peaceful companions of a similar size.

The Head and Taillight Tetra in nature is more often found in fairly neutral water but I have not experienced any issues keeping this species in slightly acidic, peat-filtered water alongside Neon Tetras, Green Neon Tetras, Black Neon Tetras, Green Neon Tetras and similar species that enjoy “blackwater” environments.

In order to maintain the softness and acidity of the water to simulate a “blackwater” environment, it is recommended that the aquarium is filtered using aquatic peat. In addition, floating and naturally decomposing Indian Almond leaves are highly recommended. 

The floating leaves provide the shaded area that the Head and Taillight Tetra will dwell beneath and the decomposing vegetation provides the tannins that will effectively synthesize the “blackwater” conditions found in the natural habitat of the Head and Taillight Tetra.

The Head and Taillight Tetra is a shoaling fish and should be kept as a group of at least six fish, though a shoal of, say, ten or more fish is highly recommended. Having plenty of vegetation to break up lines of sight will also help to protect your Head and Taillight Tetras from predation but it is obviously advised that Head and Taillight Tetras are not kept with predatory species as they are very timid.

It is fairly easy to distinguish between the sexes of the adult Head and Taillight Tetras, as the male has a pointed swim bladder whilst that of the female is rounder (when viewed against a strong light) and, when ready to breed, its colouring becomes much more intense. When the female is carrying eggs (gravid), as her lower abdomen will become more distended than the male. 

The Head and Taillight Tetra has a deeper body than most Tetras that are similar to the Neon Tetra, being much more rhomboid in shape. 

The Head and Taillight Tetra tends to inhabit the middle area of the aquarium. You should also ensure that there is a close-fitting top on the aquarium because the Head and Taillight Tetra will otherwise probably jump out, as jumping clear of the water is in its nature.

The Head and Taillight Tetra is, by nature, a shoaling fish and it is generally recommended to purchase six or more fish, as their nature is to swim together as a shoal and they will tend to thrive much better as a shoal. Head and Taillight Tetras are excellent community fish and are ideal for aquarists with moderate experience, as they don’t tend to have aggressive tendencies towards other species. It is advised not to include Head and Taillight Tetras in an aquarium containing large species, as they may consider them to be food. Head and Taillight Tetras enjoy are plenty of densely clustered plants behind and amongst which they may hide.

Head and Taillight Tetras, like most rainforest species, prefer a shaded and well-planted tank with open areas for free-swimming, as they can hide from predation or strong light, so consider including floating leaves and/or allowing vegetation to grow so that it floats on the surface of the water to provide shade. Bearing in mind the lower pH levels preferred by Head and Taillight Tetras, they should be kept is an aquatic peat-filtered aquarium

It is generally advised that the minimum tank size for Head and Taillight Tetras should be one of 24 inches in length or more due to the shoaling nature of the species, which will enable a small (or even quite a large) shoal to move around freely. The tank should be well-planted but with clear areas where the fish can swim freely. The water should only have gentle movement.

The general rule for Tetras is that by keeping six or more of the same species in an aquarium they will be fully aware of which is male and which is female and they will act accordingly when the time comes for breeding.

Most (but not all) Tetras have an additional fin which identifies them as being Tetras and the Head and Taillight Tetra is no exception. If you look between the dorsal fin and the caudal (tail) fin of the Head and Taillight Tetra you will observe a tiny, additional fin, known as the adipose fin. The purpose of this fin is not fully understood but, if it is present on a freshwater tropical fish then you can be pretty certain that the fish is a Tetra.

Tetra comes from the Greek word “Tetragonopterus” which means square-finned and appears to relate to the four fins on vertical plane of the fish (dorsal, adipose, caudal and anal fins) which span the central line of the fish (when viewed from above or below, front or rear) and are not present as a pair (e.g. the pectoral or pelvic fins).

Head and Taillight Tetra – Video

How do Head and Taillight Tetras breed?

Here’s the thing about breeding Head and Taillight Tetras…

Tetras eat their eggs and because Head and Taillight Tetras are no exception. A female will lay up to 1,000 eggs which, if laid in a community tank or a tank with a shoal of Head and Taillight Tetras in, those eggs are unlikely ever to hatch but highly likely to be eaten.

With all of the above noted then the following may be helpful for those considering breeding this pretty specimen.

Tetras, in general, will scatter eggs by laying them over fine plants such as Cabomba, Fontanalis or Java Moss.

Head and Taillight Tetras, like most species, are noted to leap above the water surface during breeding and in general, so it is advised that the tank should be covered to mitigate the risk of losing fish.

As the female Head and Taillight Tetra becomes ripe with eggs, the difference between the sexes becomes even more evident. If you plan to attempt to breed Head and Taillight Tetras then it is recommended that you have a breeding tank prepared. Such a tank can be empty but you may wish to include a mesh or grid under which the fertilized eggs will fall and/or a sterilized breeding mop.

That said, Head and Taillight Tetras will breed in a community tank and, if the tank is well planted, it is possible that at least a few fry may survive to reach adulthood.

Some say that a novice may find it difficult to breed Head and Taillight Tetras but, in my experience, by understanding the conditions that are ideal for breeding, most species will breed quite readily, as it is natural for them so to do and, in general, nature finds a way.

I have observed Head and Taillight Tetras breeding readily and vigorously in quite soft, acidic water (pH 6.0 to 6.5) and less than 12 dGH.

The female will swim vigorously around the tank and, if you include two males then they will encourage her to lay her eggs by bumping into her (though with this species, just a mature male and female is advised. She will lay her eggs which will immediately be fertilized by the male(s) and will fall to the bottom of the tank (preferably through the mesh or trap). Once spawning is complete, remove the adults, as they are likely to consume the eggs, given the chance, and take no further parental responsibility. A mature female may lay in the order of 1,000 eggs.

Spawning usually takes place in the early morning and is triggered by the rising of the sun.

Breeding tank for Head and Taillight Tetras

You should prepare a tank of around 10 gallons in size with mature water. The water should be at a pH of around 6.0 to 6.5, maintained using an aquatic peat filter and with a low level of light.

You may wish to introduce baby brine shrimp, mosquito larvae or bloodworm as an inducement to reproduction.

The female will swim amongst the plants, laying her eggs whilst the male will swim alongside or behind her and fertilize the eggs as they are laid. Typically, the female can lay up to 1,000 eggs during a spawning, which may adhere to plants or will sink to the bottom of the tank.

Once the female has scattered her eggs and the male has fertilized at least some of them then the adults should be removed carefully from the breeding tank because they will have nothing more to do with the eggs but they may simply eat them.

Keep the lights off and the tank dark because Tetra eggs and fry are particularly sensitive to the light.

The eggs will hatch typically in around twenty four hours or so depending on tank temperature and conditions and the fry will become free-swimming after a further two to three days after hatching. Keep the tank unlit for the first week or so then gradually increase the lighting.

The newly hatched fry will feed firstly on their yolk sac but, once free-swimming, can be fed infusoria (particularly rotifers) and will also thrive on egg yolk during the first two to four weeks. It is worth mentioning that immediately after hatching, fry seem quite vigorous but will soon go into a resting state before they become free-swimming so please don’t mistake this initial stage as being free-swimming.

After around four days or so add baby brine shrimp. Once the fry are sufficient in size not to be treated as a snack then they can be introduced into the community tank where they will join the existing shoal. Before moving the adolescent fish into the community tank ensure that you have balanced the water temperatures to mitigate the risk of White Spot or other diseases being triggered.

Should your Head and Taillight Tetras have a special diet for breeding?

Adult Head and Taillight Tetras don’t need any particular inducement to breed. That said, it has been suggested that adding baby brine shrimp and mosquito larva may encourage them, presumably because the addition of a new food may “fool” the fish into thinking that it is breeding time. From my own experience, I would always recommend keeping all of your fish in the best possible condition at all times, as this is good for the wellbeing of your fish.

Mike Wheeler

I started keeping freshwater tropical fish in 1972 and it has been something of a passion ever since. In this website, my aim is to build up an everyman's guide to help the everyday aquarist get the best from this inspiring and entertaining hobby.

Recent Posts