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Hatchetfish: Pictures, Size, Care, Tank Setup & More

Chris Dinesen Rogers

By Chris Dinesen Rogers

hatchetfish in aquarium

Enthusiasts who want to have a community tank have plenty of species from which to choose. You can count the Hatchetfish among them. It gets its moniker from its resemblance to the tool of its name. Coupled with its body shape with color, and you have a unique addition to our aquarium. The species lives in many countries in South America, including Brazil, Peru, and Guyana. Keep reading to learn more about these fish before adding them to your aquarium.

Quick Facts About the Hatchetfish

Species Name: Gasteropelecus sternicla
Family: Gasteropelecidae
Care Level: Easy
Temperature: 73℉–81℉s
Temperament: Peaceful
Color Form: Black, silver
Lifespan: 5 years
Size: 1.6–2.0 inches
Diet: Carnivore
Minimum Tank Size: 15 gallons
Tank Setup: Lots of structures with plants, preferably floating species, and driftwood
Compatibility: Other peaceful community species that use other areas of the tank than the surface

Hatchetfish Overview

silver hatchetfish in aquarium
Image Credit: T.Kai, Shutterstock

You’ll see this species listed as the Common Hatchetfish or River Hatchetfish. As you may expect, it lives in the Amazon River and its tributaries. It’s typically a peaceful fish, but it can get aggressive if others encroach in its space on the surface of the water. The Hatchetfish is relatively long-lived for a species of its size. It’s an active fish that will add some energy to your tank.

How Much Does a Hatchetfish Cost?

You can expect to pay between $5 to $10 apiece for the Hatchetfish. Some sellers offer them in groups for a discount. You can take advantage of a deal and get an instant school for your new additions. Like many species of its kind, it prefers having conspecifics and other peaceful fish in its waters. Not much is known about breeding, so you’ll most likely get wild-caught fish.

Typical Behavior & Temperament

The Hatchetfish is a dichotomy. It’s a peaceful tankmate, yet it’s fast. It also has a unique trait that is fitting, considering its place in the water. While darting around the aquarium, it can become airborne using the thrust from its pectoral fins. This action can help it catch insects on the wing. The fish doesn’t actually fly, but it can travel up to 13 feet.

Appearance & Varieties

marbled hatchetfish
Image Credit: Photofenik, Shutterstock

The Hatchetfish has a triangular-shaped body, with a seemingly small head and large torso. It has large pectoral fins that dwarf the size of the caudal, dorsal, and ventral fins. The color ranges from brilliant silver to a warm tan. The females are noticeably bigger than the males. The fish develops a dark horizontal stripe along its ventral side as it ages.

aquarium plant divider

How to Take Care of Hatchetfish

Paying attention to the water conditions is the key to keeping these fish healthy. That’s particularly true with wild-caught specimens. Your goal is to replicate the water chemistry of the species’ natural habitat in South America. Stability is another vital factor. Things don’t fluctuate suddenly in the wild. Remember that when considering any changes to your aquarium.

Habitat, Tank Conditions & Setup

You should recreate the Hatchetfish’s habitat and populate the tank with species that live in similar conditions. Their temperament makes this task more manageable since their needs are not out of line and are familiar to beginners and experienced enthusiasts. However, there are a few caveats that are unique to the Hatchetfish that hobbyists should know upfront.

Aquarium Size

We recommend at least a 15-gallon tank or preferably larger. The fish can get a decent size. They also occupy the top of the aquarium near the surface. You should opt for a rectangular one with a decent amount of top space. Avoid getting vertical aquariums. Remember the Hatchetfish’s ability to go airborne. Besides, it needs some room to rev up its fins.

Aquarium light
Image Credit: TIPAKORN MAKORNSEN, Shutterstock

Water Conditions

The water in the Amazon is soft, with a preferred dH of 6–15. The optimal pH is 6.0–7.5, making the water slightly acidic. The Hatchetfish is a tropical species, making temperatures between 73℉–81℉ ideal. We strongly urge you to monitor the conditions closely with at least biweekly testing. You should also watch the ammonia, nitrite, and nitrate levels.

These parameters are likely a problem for the Hatchetfish in its native waters. Even slow-moving streams will keep these variables in check. You should also do bimonthly water changes to ensure the conditions stay stable and remove debris.

Tank Setup: Plants, Substrate, and More

The Hatchetfish thrives in a planted tank. They will provide welcome cover for a fish that is also a prey species. You should also include some floating varieties since it swims near the surface. Vegetation doesn’t form a significant part of its diet. However, using live plants versus artificial ones creates a more natural environment.

We recommend using a dark-colored substrate. The silver color of this species will pop against this background. A heater and hood are essential. Without the latter, you’ll probably lose a fish or two during their airborne runs.

aquarium plant divider

Are Hatchetfish Good Tankmates?

The swimming habits of the Hatchetfish provide an excellent way to populate a community tank with species occupying different layers. Livebearers, larger tetras, angelfish, and Dwarf Gouramis will make suitable tankmates. Remember that this species is carnivorous, although it prefers insects and plankton instead of other fish.

We don’t recommend keeping them with other fast and semi-aggressive fish like Tiger Barbs. Likewise, their energetic nature would probably stress slow-moving varieties, such as Bettas. Adding bottom feeders, such as Otocinclus Catfish, can help maintain healthy conditions to benefit all the fish.

hatchetfish in aquarium
Image Credit: Andrej Jakubik, Shutterstock

What to Feed Your Hatchetfish

You can offer your Hatchetfish freeze-dried and live foods, such as bloodworms and brine shrimp. They may also eat flake foods. We recommend feeding only as much as you observe your fish consume. These foods can quickly foul the water if you overfeed them. If your fish won’t take flakes or pellets, give them live foods that they’ll recognize as something to eat.

Keeping Your Hatchetfish Healthy

Stable conditions are the key to keeping Hatchetfish healthy. Wild-caught fish may be unable to cope with variable waters since they aren’t well-adapted to these situations. Many species can handle temporary stress but may lack the ability to survive them in the long term. Loss of appetite and lethargy are telltale signs that something is wrong. Therefore, we recommend observing your fish daily.


Not much is understood about breeding Hatchetfish. Scientists know this behavior is associated with climatic events, like seasonal flooding. That can make replicating the necessary conditions difficult, if not impossible. We recommend maintaining the preferred conditions and hope for the best. The female will lay eggs on structures inside the tank.

Are Hatchetfish Suitable For Your Aquarium?

Hatchetfish are fascinating animals. Their appearance is striking and makes their fast swimming even more entertaining. As long as you have a tight-fitting hood, your fish will stay in their tank and not on the floor. They make excellent tankmates with other peaceful South American species. You’ll have your aquatic pets for a long time with the proper conditions.

Featured Image Credit: slowmotiongli, Shutterstock

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