Common Hatchetfish: Species Overview

Category: Hatchetfish

Common Names: Common Hatchetfish

Scientific Name: Gasteropelecus sternicla

Family: Gasteropelecidae

Minimum Tank Size: 20 Gallons

Care Level: Moderate

Temperament:  Peaceful

Max Size: 2 Inches

Temperature: 74-78 F

pH: 6.0-7.0

Tank Level: Top

Colors: White, Tan

Diet: Carnivore

Breeding: Difficult

Common Hatchetfish with Grass

Common Hatchetfish: Species Overview

Common hatchetfish are a popular choice for home aquariums. They are quick freshwater swimmers with a unique appearance and a penchant for jumping out of fish tanks. They have a reputation for being challenging to keep healthy, which may be unfair.

Whether you’re a novice fishkeeper or a seasoned expert, the common hatchetfish is one that you can take care of with some practice. So long as your tank has a sturdy lid and you maintain your water quality, the common hatchetfish might be suitable for your tank.

Remember that the common hatchetfish is a distinct and separate species from the silver hatchetfish, though some fish store owners might not know the difference. It’s pretty common for both species to appear in a store under one name.

The common hatchetfish is typically larger than the silver and bears the scientific name, Gasteropelecus sternicla. The silver hatchetfish is known as Gasteropelecus levis. Make sure you understand precisely which species of hatchetfish you’re buying, as they each may have special needs.

For example, silver hatchetfish are shy in the extreme.

Other common species of hatchetfish you might see for sale include the marbled hatchetfish (Carnegiella strigata), Blackwing hatchetfish (Carnegiella marthae), and the spotfin hatchetfish (Thoracocharax stellatus).

You might also find some examples of these less common hatchetfish:

  • Pygmy Hatchetfish (Carnegiella myersi)
  • Giant Hatchetfish (Thoracocharax securis)
  • Dwarf Hatchetfish (Carnegiella schereri)

Distinguishing Features

The common hatchetfish has a triangular profile that mimics a sharp hatchet. But instead of chopping wood, these tiny, agile swimmers slice through the water. They are most often silvery-gold in color.

They’re highly maneuverable, and their strong pectoral fins are almost wing-like, enhancing their agility.

Viewed from the side, the common hatchetfish and most other hatchet fish have a low-hanging abdomen that is a tone lighter than their back’s coloring. The common hatchetfish has a wide anal fin that runs along the fish’s underside until it meets the double, triangular tail fin.

They also have a relatively prominent latitudinal black stripe that runs from the middle of the tail fin along the flank to the pectoral fins. This stripe roughly divides the upper and lower body.

The fins are all transparent and lend an almost spectral air to these flashy swimmers. Common hatchetfish have an upturned mouth, and their eyes also seem to tilt toward the surface, giving these fish a distinctly predatory look.


The common hatchetfish is native to the waters of Central and South America. It is found in the rivers, streams, and flowing flood plains of the Amazon basin, as far west as Peru and as far north as Venezuela.

Common hatchetfish can also be found in Suriname and Guyana. Since they’re most often seen in rivers, the common hatchetfish is sometimes called the river hatchetfish.

Typically, their environment has a silty, sandy bottom, an abundance of vegetation, and clear fresh water. The common hatchetfish species thrives in streaming waters with a steady, easy current, ample floating vegetation, and plenty of open space for swimming.

Even in nature, they are pretty shy and may be seen clustering along the edges of the waterway, where rocks, roots, leaves, and grasses may help them find a hiding place. They love to hide under floating plants.


In general, the common hatchetfish is about 2.5 inches long. Though fairly small compared to some freshwater aquarium fish, they are a bit larger than many other hatchetfish species.

The female gender of the common hatchetfish is typically larger than her male counterparts. Some specimens can end up as long as three inches.


Even well-fed, well-cared-for common hatchetfish may only survive for two years. They are very vigorous, but this brief lifespan contributes to a perception that the common hatchetfish is hard to keep in an aquarium.

While there are no guarantees, you may have some hatchetfish that live considerably longer lives, reaching a lifespan of five years or more. Make sure you’re doing all you can to keep your fish healthy, and you may reach the upper ranges of their lifespan.

Distinguishing Genders

The female common hatchetfish is larger than the male, on average. They also appear plumper, but it can be hard to tell them apart.


Common hatchetfish do best in larger groups. A single fish is unlikely to act normally or be content. As a rule, you should keep a school of at least six common hatchetfish. Even larger groups are better and will help the fish feel more comfortable.

Especially when first acclimating to a new environment, the common hatchetfish is likely to be quite reserved or shy. They may even refuse to eat until their nervousness abates.

Even after they have gotten used to their new surroundings, it’s not uncommon for common hatchetfish to try and hide most of the time. They can be easily scared by other fish and human stimuli, so avoid excitable tank mates and anything loud or flashy in the room with the common hatchetfish tank.

Overall, they’re a calm species of fish, unlikely to start trouble with others in their tank. But, they are also carnivorous predators, so be careful about introducing anything to the tank that might appear as a potential food source.

Two Common Hatchetfish with Grass

Tank Parameters

When designing and setting up your tank for common hatchetfish, remember to try and mimic their natural environment as much as possible. Make sure that you don’t introduce anything with artificial colors that might leech into the water.

Minimum Tank Size

For the best results, you should keep your common hatchetfish in a tank that is at least fifteen gallons. While they could probably survive in a smaller tank, they won’t be as happy. And if you have the room, a tank of twenty gallons would be better, even if you only have a handful of common hatchetfish.

Obviously, the larger the school of common hatchetfish you keep, the more room you will need to accommodate their need for ample hiding places, mixed with plenty of space to swim.

The single most important feature your tank needs, besides the proper capacity, is a heavy lid.

The common hatchetfish is very good at jumping out of the water. In the wild, most species of hatchetfish use their powerful pectoral fins to propel themselves out of the water to snatch bugs or larvae on the surface.

Common hatchetfish kept in captivity don’t jump quite as well as their wild cousins. They can also leap from the water when threatened. But it’s not entirely uncommon to find common hatchetfish on the floor or in other nearby tanks after a leap.

So, you may need to place a weight on top of the tank’s lid or use some sort of fastener to ensure that it stays closed. Maintaining about four or five inches of buffer space between the top of the water and the tank’s lid is also advisable. This space can help avert injuries from fish leaping and hitting the cover.

Water Parameters

Common hatchetfish are tropical, freshwater fish. Keep that in mind when setting up the water for their tank.


Common hatchetfish need a consistent water temperature between 72 and 79 degrees Fahrenheit. Try to avoid letting the temperature fluctuate too widely.

If there is a strong source of natural light that might warm the tank, consider using shades to reduce the amount of sun that hits the water. Doing so can help prevent the water from becoming too warm for your fish.


Common hatchetfish tanks should have a mildly acidic water profile. A range of pH from 6.2 to 6.8 is ideal.


There shouldn’t be any salt in the water for common hatchetfish. They will tolerate mildly hard water, but the hardness should never exceed 14 degrees of carbonate hardness (dKH).

Tank Setup

Again, your tank setup should match the native habitat of the common hatchetfish as closely as possible.


You can use your imagination a bit when considering your common hatchetfish tank’s substrate. They rarely spend much time near the bottom of the water, so you can mix and match with gravel, sand, and pebbles. Some keepers even use clay as a substrate for their common hatchetfish tank.

The river beds under common hatchetfish in their natural setting are often fine and silty sand, so it’s ok if you use a very fine substrate that tends to stir when fish swim energetically, creating a temporary cloud at the bottom.

You should avoid using anything with sharp edges in general, just to help your fish avoid

accidentally hurting themselves should they brush up against something. Since common hatchetfish love to hide, take special care not to have anything sharp they might bump into when looking to do so.

Some keepers use a darker substrate to help accentuate the flashy, silvery colors of the common hatchetfish.


Since common hatchetfish are very timid, it makes sense to use your decorations to provide lots of nooks and crannies for hiding places. Rocks, driftwood, buried PVC pipes, artificial castles, and other objects can all help give shelter for lurking common hatchetfish.

You shouldn’t introduce anything to the tank that might have sharp edges that could injure your common hatchetfish when they flash in and out of their hiding places.


The tropical waters native to the common hatchetfish have rich and abundant plant life. In particular, their natural habitat has a lot of floating flora and thin, reedy grasses that move with the flowing current. These offer ideal places for shy fish.

Plants in general help provide hiding places for the ultra-shy common hatchetfish. However, it’s critical that you balance the amount of flora and decorations with their need for plenty of free swimming space.


The common hatchetfish require a relatively simple lighting setup.

The use of a timer that turns your lighting system on and off can help make it easier for you to maintain a consistent night and day balance. You should provide about ten hours of darkness.

If your tank happens to be in a room with other sources of light, you should take care to dim them when the tank’s lighting turns off.

Overall, the lighting levels need not be overly bright or dark.


Like most freshwater fish, common hatchetfish require clean, fresh, flowing water. Ammonia and nitrates can become poisonous, so be sure to have a filter with adequate capabilities for your volume of water.

It’s also important not to use an oversized filter that creates excessively forceful currents that make it hard for your fish to swim around.


Since they require tropical water temperatures, you will need a heater to maintain the proper water temperature.


The common hatchetfish is carnivorous and has a predatory instinct. Fishkeepers need to maintain their diet with abundant amounts of protein. It’s a good idea to provide a few sources of food with as much variation as possible.

This keeps the fish interested in what you’re offering, as well as providing a balanced and nutritious diet. Don’t let their diet become too monotonous, or they will become bored and listless.

They will eat fresh and frozen food, and they’re not overly finicky. But since they’re pretty small, you may need to cut larger pieces into smaller fragments. It’s also advisable to let frozen food soak in warm water for a few moments before introducing it to the common hatchetfish tank.

This technique helps make it easier for the fish to consume the morsels and helps prevent choking.

In addition to frozen and dried fish foods, you can use bloodworms, fruit flies, brine shrimp, mosquito larvae, tubifex, and daphnia to feed your common hatchetfish.

Some species of hatchetfish will tend toward an omnivorous diet, where they supplement protein-rich, animal-based food sources with plants. You can further vary your common hatchetfish diet by introducing blanched vegetables like spinach and string beans.

Common Hatchetfish on White Background


It is unlikely you will be able to breed common hatchetfish in captivity. It is so tricky that there are no known ways to do so and no examples of success.

Other hatchetfish are far more likely to breed in captivity, and it’s relatively easy. If you want to try, you can increase the oxygen level and boost the water temperature.

If you’re on the right track, your female will hide thoroughly, and the male will show signs of increasing activity. The male will find the female and fertilize the eggs, and you will see the female swimming freely.

The male will watch the eggs, which takes about a week. Then, you’ll need to provide the fry with food that has been crushed into fine material.

Most hatchetfish fry develops a small, yellow egg sac that sits under their bellies when they hatch and disappears within a few days. The female will keep an eye on them as they grow. Within a few weeks, the hatchetfish fry will be almost fully developed.

Common Diseases

The biggest health threat to common hatchetfish comes from parasitic Ich. To reduce the odds of an infestation, always quarantine anything that you’re introducing into your tank. Only add it to your established habitat after an observation period.

Look for any fish that appear lethargic or that seem to drag their bodies along surfaces, trying to scratch themselves. If you suspect Ich, you can isolate any affected fish and use a commercially-prepared medication to treat it.

Often, you will also have to raise the water temperature and add a bit of salt to the water.

Regular water changes and clean water are the best way to avoid Ich in your aquarium.

Potential Tank Mates

The ideal tank mates for the common hatchetfish are those that won’t compete for food or act aggressively. Very fast, hungry fish might consume all the food available before the more timid common hatchetfish get a chance to eat.

Some of the best partners to add to a common hatchetfish tank include corydoras, dwarf cichlids, tetras, shrimp, some crab species, snails, and loricariids.

In general, the best co-habitants for common hatchetfish are other common hatchetfish. They prefer to hang out in groups of at least six, but they may behave less skittishly in even larger schools.

Bottom Line

Common hatchetfish are timid by nature, and they don’t often live as long as we might hope. But, they have a distinctive appearance, and their overall care needs are pretty easy to keep up with if you’re consistent with your tests and observations.

While they do require some specialized attention, like frequent water changes and a careful eye for Ich, they can be a fun addition to any tank that meets their requirements. They love swimming in schools. Plus, they’re pretty easy to find in fish stores, where you can go and buy some today!