Minimum Tank Size: 20 Gallons (75 Liters)
Care Level: Very Easy
Water Conditions: PH 5-5-7.5 Soft to Moderately Hard
Temperature: 72-79°F (22-26°C)
Maximum Size: 2 inches (5 cm)
The head-and-taillight tetra (Hemigrammus ocellifer), also known as the beacon tetra, is a small and popular beginner fish. They have the distinction of being one of the best-suited tetras for community tanks, and because of their ease of care and peaceful nature, they can be found in nearly every store that sells fish.
Few – if any – of the head-and-taillight tetras available for sale are still wild caught, and most are bred on vast fish farms in Eastern Europe and Southeast Asia. Because of this, head-and-taillight tetras can adapt to a wide variety of water types – unlike their wild cousins.
These fish are native to the rivers of Suriname, Guyana, French Guiana, Brazil, and Peru. They are found in coastal regions and prefer slow-moving water. They inhabit rivers, streams, freshwater lagoons, and floodplain lakes.
These fish live between three to five years in a home aquarium, though a lifespan of around three years seems to be around average. They will grow to a maximum length of 2 inches (4.5cm).
Head-and-taillight tetras are an undemanding fish, and a group of these fish can be comfortably housed in a 20-gallon (75 litre) aquarium. They should always be kept in groups of at least six but seem to thrive when kept in groups of ten or more. As these fish are non-aggressive, they will do well with most peaceful fish in a community aquarium.
When setting up an aquarium for these fish, their natural habitat should be mimicked as closely as possible. A sandy substrate is preferred with leaf litter lining the bottom, and driftwood should be added to provide hiding places. While their aquariums don’t have to be planted, live plants are always an excellent addition to aquariums, but it’s important to leave open areas for swimming.
Some aquarists attempt to recreate black water conditions with peat and leaf litter (which helps to lower the pH), but as long as the lighting in the tank is somewhat muted, it’s not necessary to go to the lengths required to create a black water tank.
As head-and-taillight tetras prefer little to no current, extra care should be taken when choosing their filter. While a hang-on-back filter is usually the preferred choice in small aquariums, it may provide more current than these fish are comfortable with. But the current can be lessened to more tolerable levels by lowering the flow from the filter.
The filter I always recommend is the Aquaclear Power Filter, which is both affordable and incredibly durable. A sponge filter would also be a good candidate for use in a head-and-taillight tetra aquarium.
Head-and-taillight tetras are omnivores, and in the wild, feed on small insects, worms, crustaceans, and plant matter. This diet should be replicated as closely as possible in the home aquarium, and this can be done by offering these fish a high-quality flake food, along with regular feedings of frozen and live foods.
I personally recommend Hikari Micro Pellet Fish Food, as it provides all the needed nutrients and vitamins for the fish. When it comes to choosing live food, they will greedily accept blackworms (tubifex in Europe), daphnia, gut-loaded brine shrimp, and mosquito larvae (illegal to culture in some areas). Their preferences are similar for frozen food, and they can be fed bloodworms, blackworms, and brine shrimp.
Head-and-taillight tetras are notoriously prolific and will often breed in an aquarium with no intervention from the aquarist. However, very few – if any – of the fry will normally survive in a community tank.
The males have a more pointed swim bladder than the females, while the females have a slightly covered swim bladder, so it appears more rounded underneath. The females also tend to be larger than the males, with a rounder body.
If the goal is to breed these fish, then a separate breeding tank should be setup. The breeding tank should be fully cycled prior to adding fish to it. Only the barest of lighting should be provided for the tank, and often ambient room lighting will be more than adequate. But once spawning has occurred, it’s important to keep the tank in near darkness as the fry are very sensitive to light.
The breeding tank water should be soft and acidic, and there are several ways to lower the pH of an aquarium. For more information on safely lowering the pH in an aquarium, read the Aquarium Tidings article – How to Safely Lower the pH in an Aquarium.
For successful breeding to occur, it’s important to add fine-leaved plants such as Water Sprite or Java moss to the breeding tank. Artificial spawning mops will also work, but in my experience, fry seem to have a better survival rate with live plants. The plants or spawning mop will provide a surface for the fish to deposit their eggs on, and the dense, interwoven leaves of the plants will help to protect the eggs from the adults.
Once the tank is properly setup, it’s simply a matter of adding a small group of males and females. They should then be conditioned by providing them with live or frozen foods. Soon afterward, spawning should occur.
It’s important to remove the adults after the eggs have been deposited on the plants, as they will eat the eggs and any fry that eventually hatch. The survival rate of the fry will likely be very low if the adults aren’t removed from the aquarium.
The eggs normally hatch after 24 hours and will become free swimming after around three days. The fry can be fed infusoria or commercially available fry food, until they are large enough to consume baby brine shrimp and microworms.
Community Tank Compatibility
Head-and-taillight tetras are an excellent beginner fish and are renowned for their peaceful nature in community aquariums. They will do well in aquariums containing danios, corydoras catfish, rasboras, most peaceful gouramis, dwarf cichlids, and my personal favorite – rosy red minnows.