Information, Characiformes (Characins), Freshwater fish, Species, Tetras

Head and tail light tetra (Hemigrammus ocellifer)

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by Jason Matthews



The Head and Tail Light Tetra, also known as Hemigrammus ocellifer, is a popular and vibrant fish species ideal for beginning and intermediate fish keepers. With their striking appearance and peaceful nature, these fish are sure to add color and personality to any tank. 

This article will delve into the world of the Head and Tail Light Tetra, covering everything from their origin to their diet and breeding habits. So come along to learn about the wonders of this fascinating species and how to properly care for them in your own tank.


Scientific Name: Hemigrammus ocellifer
Common Names: Head and Tail Light Tetra, Beacon Fish, Beacon Tetra
Life Expectancy: 5 years
Adult Size: 2 Inches


HabitatGuyana, Surinam, and Brazil
OriginSouth America
Care LevelEasy
DietOmnivorous, Flake or pellet food
Tank LevelMiddle
Minimum Tank Size20 gallons
Water pH6.0-7.5
Water Temperature22-26°C
Water HardnessSoft to Moderately Hard
Tank MatesPeaceful community fish

Fun Fact Corner

A fascinating fact about the Head and Tail Light Tetra is that they exhibit a distinct behavior known as “flashing.” When the fish rapidly flashes its lights on and off, it is thought to communicate with other school members. This behavior is most commonly observed in low light conditions and is an intriguing aspect of the species that owners can keep. This behavior is also unique to this tetra species, making it an exciting feature to watch in your tank.


The Head and Tail Light Tetra, also known as Beacon Tetra, is a type of fish native to South American rivers and streams, specifically in Brazil, Colombia, and Peru. These fish are typically found in these rivers’ lower and middle reaches, where the water is slow and warm. They are also common in swamps and flooded forests. Except for the countries mentioned above, the Head and Tail Light Tetra is a freshwater fish that is not found in the wild anywhere else in the world.

This species has been known to science since at least 1891 when German ichthyologist Carl H. Eigenmann first described it. Since the 1930s, it has been a popular species in the aquarium trade, and it is widely distributed in the pet trade worldwide.

Appearance & Size

The Head and Tail Light Tetra is a small, colorful fish with an eye-catching appearance. They have sleek and streamlined bodies, as do most tetra species. The body is silver in color and has a slightly iridescent sheen to it.

The Head and Tail Light Tetra’s most distinguishing feature is the bright red and blue markings on its head and tail, which give it its common name. The red mark on the head, just behind the eye, is incredibly noticeable and vivid. The blue marking on the tail is also noticeable and contributes to the overall coloration of the fish.

The dorsal fin is round and short, whereas the pectoral fins are long and pointed. The anal fin is short and rounded, while the caudal fin is forked slightly. The fins are usually transparent or translucent, adding to the fish’s overall elegance.

The Head and Tail Light Tetra is a peaceful and active fish that should be kept in a group of at least 6 to 8 other fish. This will help to bring out the fish’s natural swimming and shoaling behaviors and make the environment more stable and healthy for the fish.

The Head and Tail Light Tetra is a small fish that grows to about 5 centimeters in length. These fish can grow slightly more significantly in ideal conditions.When keeping the swimming requirements of Head and Tail Light Tetra, it is critical to consider them. These fish are active swimmers who require plenty of open swimming space in their tank. They should also have plenty of safe hiding places and plants to explore.


The Head and Tail Light Tetra is a sexually dimorphic species, which means that males and females have distinct physical differences. Once you know what to look for, identifying the sexes of these fish is relatively simple.

Males are slightly more colorful and have longer fins, especially the dorsal and anal fins. They also have brighter red and blue markings on the head and tail. On the other hand, females are slightly larger and plumper, with shorter fins and less vibrant coloration.

It’s important to note that keeping Head and Tail Light Tetra in an aquarium with at least two females to one male is recommended to reduce the possibility of male aggression.


Head and Tail Light Tetras are known for their peaceful and active behavior. They are shoaling fish, which means they prefer to live in groups and will do well in an aquarium with at least 6-8 other fish. They are also enthusiastic swimmers who enjoy exploring their surroundings. 

They frequently swim near the water’s surface and are active during the day.

When kept together, these fish will exhibit natural shoaling behaviors such as swimming in unison and staying close to one another. This behavior is entertaining and can add a unique dynamic to your aquarium.

It’s worth noting that these fish are relatively peaceful and should not be kept with aggressive or larger fish species that could bully or harm them. They should also have plenty of hiding spots and plants to make them feel safe.


When choosing tankmates for Head and Tail Light Tetras, look for fish with similar water conditions and peaceful behavior. Because these fish are small, they should not be kept with larger, more aggressive fish that may bully or harm them.

Here are some suitable tankmates for Head and Tail Light Tetras:

It’s also important to consider the size of your aquarium when selecting tankmates. Overcrowding your tank can cause water quality issues and stress for the fish.

Tank conditions

Head and Tail Light Tetras are adaptable to tank conditions and thrive in various settings. However, certain conditions must be met to ensure these fish’s health and well-being. To provide enough swimming space for a group of these fish, the aquarium should be at least 20 gallons and at least 24 inches in length. A tight-fitting lid is also recommended to keep the fish from jumping out of the tank.

Head and Tail Light Tetra should be kept in water that is 72-82°F, has a pH of 6.0-7.5, and has a hardness of 5-20 dGH. They also necessitate a moderate amount of water flow and filtration. It’s also a good idea to fill the tank with plants like Java Moss or Hornwort and some hiding spots. This will make the fish feel safer while providing a more natural environment.

It is important to note that regular water changes and testing are required to maintain the proper water conditions for these fish.

They are suitable for smaller aquariums because they can be kept in tanks as small as 10 gallons. However, as with any fish species, providing them with a larger tank is always preferable so they have more room to swim and live in a more stable and healthy environment.

It’s also worth noting that if you keep these fish in groups, you’ll need to increase the tank size accordingly. 


Head and Tail Light Tetras are not picky eaters and will accept a wide range of food options. They are omnivorous, which means they consume both plant and animal-based foods.

They primarily feed on insects, worms, crustaceans, and plankton in the wild. Providing a balanced diet of protein- and plant-based foods in captivity is important.

Some suitable alternatives include:

  • Flake food: Provide high-quality flake food as a staple diet.
  • Pellets: Provide specially formulated small pellets as a staple diet.
  • Live and frozen foods: Offer live or frozen foods such as brine shrimp, daphnia, or bloodworms as a treat occasionally.
  • Vegetables: Offer blanched spinach, lettuce, or peas as a supplement to the diet.

It’s important to feed your fish sparingly, as this can result in poor water quality and health issues. It is best to feed small amounts several times per day.


Breeding Head and Tail Light Tetras can be a rewarding experience for fish enthusiasts. In captivity, these fish are relatively easy to bear, and they will produce readily with the right conditions and setup. Providing a suitable environment for breeding Head and Tail Light Tetras is important.

Consider the following important factors:

  • Water conditions: The water temperature should be around 78-82°F (25.5-28°C) with a pH of around 6.5-7.5. The water should be soft and slightly acidic.
  • Tank size: A breeding tank should be at least 20 gallons in size, with plenty of hiding places and dense vegetation.
  • Lighting: Provide low lighting to mimic the natural conditions of their habitat.
  • Diet: Feed the fish a varied diet that includes both protein and plant-based foods.

Males will display their best colors and engage in courtship rituals when the fish are ready to breed. The females lay eggs in dense vegetation or on the spawning mop. The eggs hatch in 24-36 hours and the fry are free to swim in 3-4 days.

It is important to note that Head and Tail Light Tetras are egg scatterers, which means that the eggs are released into the water without any care from the parents. It is best to separate the fry from the adults as soon as they are free-swimming to avoid being eaten.


When it comes to the health of your Head and Tail Light Tetra, it is important to be aware of potential diseases that can affect them. Ich, also known as White Spot Disease, and Fin Rot are two common diseases that can affect this species. Ich is caused by a parasite and is distinguished by white spots on the fish’s body. On the other hand, Fin Rot is caused by poor water quality and is determined by the fish’s fins becoming frayed and discolored.

To prevent the spread of disease, it is important to maintain proper water conditions and perform regular water changes. Additionally, providing a balanced diet and avoiding overcrowding in the tank can aid disease prevention. If you suspect that your Head and Tail Light Tetra has a disease, you should consult a veterinarian specializing in fish health. Early detection and treatment can greatly improve recovery chances.


Jason Matthews

My name is Jason Matthews, and welcome to my website. When other kids were bragging about how their dog could sit and roll over, I was bragging about my latest Betta Fish and the cool sea castle I just added to his aquarium. 

Jason aquariume

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