Hatchetfish Care Guide: A Deep Dive into Aquarium’s Flying Wonders


Hatchetfish Care Guide: A Deep Dive into Aquarium’s Flying Wonders

Hailing from the heavily vegetated waters of the Amazon River Basin in South and Central America, Hatchetfish are unusual surface dwellers that make for an exciting departure from the typical bottom to mid-water freshwater fish you may be familiar with.

So if you want to fill in the upper third of your community tank with a unique aesthetic and active presence, Hatchetfish may just be exactly what you are looking for.

Their distinct hatchet-shaped body, particularly their large, wing-like pectoral fins and upturned mouth, isn’t just for show. It is an adaptation that allows them to dwell near the water surface, filling a zone often neglected in home aquariums.

And not only does this unusual body shape make them dwell on top, but it also allows them to fly out of the water!

This behavior, along with their interesting body shape, has earned them a unique place in the aquarium hobby.

But while freshwater hatchetfish are a captivating addition to any aquarium, they are not necessarily the easiest choice for beginners.

Fret not, because you are in for a great treat!

This Hatchetfish Care Guide will cover all aspects of hatchetfish care in detail, helping you give your hatchetfish a healthy and happy environment.


Hatchetfish Overview

Belonging to the Gasteropelecidae family, Hatchetfish get their name from their unique, you guessed it, hatchet-shaped bodies.

Like their relatives – the tetras, silver dollars, piranhas, and pacus – hatchetfish are part of the Characiformes order. But there’s one thing that really makes hatchetfish stand out – they fly!

In their natural habitat, hatchetfish are able to “fly” out of the water using their pectoral fins to escape predators or capture their prey such as tiny insects and mosquito larvae.

The jump can be quite powerful, allowing them to reach a substantial height above the water’s surface. It’s not uncommon for a startled hatchetfish to leap more than 4 feet into the air!

It is important to note, however, that despite their predatory skills, they are peaceful fish. Hence, you would not need to worry about them being aggressive to other species in your aquarium hobby.

Habitat and Tank Conditions for Freshwater Hatchetfish

Tank-Setup Because these fish spend their time near the surface, hatchetfish have a higher exposure to atmospheric air, which allows them to breathe air directly.

However, this adaptation also means that they have a more delicate respiratory system, making them sensitive to water quality issues.

Thus, these delicate aquarium fish thrive best in a mature aquarium where no water parameter fluctuations can be observed. In other words, the water in your tank must be stable enough before you put them in!

Tank Size

When choosing a hatchetfish aquarium, it is important to remember that they are known for their jumping ability, which means that a tightly covered tank is non-negotiable.

Moreover, they are schooling fish, so a minimum tank size for freshwater hatchetfish is ideally around 20 gallons to keep a hatchetfish school of at least 6. This space allows hatchetfish to swim freely and comfortably at the water surface.

Water Parameters

Ensuring the water’s chemistry is stable and within acceptable ranges will help mimic the soft water conditions hatchetfish are accustomed to in their natural habitat.

Although the following may vary slightly depending on the specific freshwater hatchetfish, here are some acceptable ranges to maintain in your home aquarium.

  • Water temperature: 72 to 83 degrees Fahrenheit
  • pH level: 5.2 to 7.0 (pH level should be maintained as this could lead to stressful behavior in the fish)
  • Water hardness: 2 to 15 dKH

Also, keep ammonia and nitrites to a minimum (ideal range < 20 ppm), as these can cause serious health problems for hatchetfish.

Tank Decorations and Substrates

Creating an environment that closely mimics a hatchetfish’s natural habitat is the key to their well-being. This means careful selection of tank decorations and substrates plays a significant role in their health and happiness.

Floating Plants and Light Preference for Hatchet Species

By now you must be familiar with hatchetfish being surface dwellers, so it must not be surprising to know they need floating plants. As they primarily inhabit the upper levels of the water column, floating plants are a fantastic addition to the freshwater hatchetfish aquarium. These plants not only provide hatchetfish with cover and security, making them feel safer and more comfortable, but they also simulate the vegetated waters found in their natural habitat.

Intense, bright lights can stress Hatchetfish and cause them to be less active, so using dimmer lights or providing ample floating vegetation to diffuse the light is beneficial to keep them comfortable.

Some common examples of floating aquatic plants
  • Duckweed
  • Water Lettuce
  • Water Hyacinth


Now, if you’re scratching your head wondering, “What’s a substrate?”, it’s simply the stuff at the bottom of your tank. When choosing your substrate for a hatchetfish setup, think dark. Why? Because hatchetfish are big fans of dark-colored substrates.

You see, these fascinating fish come from wild habitats where they’re used to hanging out over dark river bottoms. Replicating these conditions with a darker substrate can transport your freshwater hatchetfish right back to their natural environment. Plus, it’s not just about your hatchetfish feeling at home, it’s about creating an engaging display for you to enjoy.

With a dark substrate, you’ll enhance the visual appeal of your aquarium and promote your hatchetfish’s natural behaviors. They’ll feel more comfortable, and in turn, become more active. And voila, you’ve got a lively, aesthetically pleasing hatchetfish display.

Fine sand, gravel, and aqua soil are some of the most common substrate options.

Suitable Tank mates for Hatchetfish

Hatchetfish, being the peaceful fish they are, live life at the top of the tank. So, we need other fish species that prefer the middle or bottom regions of the water column.

It’s like organizing a party – you want everyone to have their space to boogie without stepping on each other’s fins. Other surface dwellers are, unfortunately, not invited.

Care must also be taken when considering aggressive, large, or highly active fish as their tank mates, since they may intimidate or even prey on these tiny fish.

So, who gets an invite to the hatchetfish party? Here’s a list of good tank mates for your hatchet:

  • Tetras: These little swimmers are peaceful and colorful, and they prefer to hang out in the middle of the tank – perfect!
  • Corydoras Catfish: These bottom dwellers are a fantastic option. These laid-back tank mates will keep the bottom-level hustle-bustle alive.
  • Dwarf Cichlids: These guys are peaceful enough to coexist with hatchetfish, and they add a beautiful splash of color to your tank.
  • Rasboras: Yet another middle-tank dweller, these peaceful fish will happily coexist with your hatchetfish.
  • Plecos: Plecos will stick to the bottom, minding their business, and doing a bit of cleanup as they go.
  • Tiger Barbs: Okay, here’s where things get a bit tricky. With enough buddies (at least 10), tiger barbs will largely stick to themselves, minimizing the fin-nipping. However, keep a close eye on their behavior – if they start causing trouble, it might be time for an early exit.

So there you have it – a diverse, compatible community of tank mates for your hatchetfish!

What are the common species of hatchetfish?

Hatchetfish are predominantly freshwater fish and encompass around nine species, but only four species commonly make their way into the aquarium hobby. These four include:

  • Silver Hatchetfish (Gasteropelecus levis)
  • Marbled Hatchetfish (Carnegiella strigata)
  • Common Hatchetfish (Gasteropelecus sternicla)
  • Blackwing Hatchetfish (Carnegiella marthae).

Pygmy Hatchetfish (Carnegiella myersi) is another species that is less common but equally captivating.

So, whether it’s the Silver Hatchetfish with its shiny silver body or the Marbled Hatchetfish with its attractive patterning, each species of hatchetfish brings something special to a community tank, making them a favorite in the aquarium hobby.

Silver Hatchetfish (Gasteropelecus levis)

While all the hatchetfish species generally exhibit skittish behavior and a tendency to stay near the water’s surface, Silver Hatchetfish is said to be the shyest hatchetfish to exist.

They are native to the heavily vegetated waters of floodplain lakes, slow-flowing tributaries, and rivers across Central and South America, where a lot of floating aquatic plants are observed.

And since they are shy, replicating these conditions to provide ample cover to these timid wonders in your home aquarium is key to a happy hatchetfish!

Appearance and Lifespan of Silver Hatchetfish

With its small size, reaching a maximum length of about 1.5 to 2.25 inches (4 to 5.72 centimeters), this species has a life expectancy of about 3 years in captivity. They are smaller than common hatchetfish but are larger than marbled and Blackwing hatchetfish.

As the name suggests, silver hatchets showcase a shimmering silver body with a prominent black spot near its gill cover, resembling the shape of a hatchet.

The black spot near their gill cover is one way to distinguish Silver Hatchetfish from Common Hatchetfish, which lacks this feature.

Behavioral Patterns of Silver Hatchetfish

Silver Hatchetfish are schooling fish, so make sure to keep them in a school of at least 6!

Keeping them in schools makes them thrive in the company of their own kind and other non-aggressive fish species. Their schooling behavior is a survival tactic against predators, providing safety in numbers.

Like any other, silver hatchetfish spend their time on the surface and may even jump out of the aquarium. As such, a tightly covered tank is essential to prevent them from jumping out.

Diet for Silver Hatches


Ever wonder why hatchetfish species sport an upturned mouth?

It’s because, in the wild, they feed on small insects, larvae, and other tiny organisms that fall on the water’s surface. Their upturned mouth allows them to scoop up food from the surface easily.

And like their other Hatchetfish counterparts, Silver Hatchetfish are primarily carnivorous.

If you’re contemplating what diet Silver Hatchetfish needs, consider a balanced blend of live nourishment and high-quality fish flakes. Live or frozen foods such as blackworms, brine shrimp, daphnia, mosquito larvae, and tubifex are also excellent supplements for their diet.

A piece of advice, be careful not to overfeed your Silver Hatchetfish!

A good rule of thumb is to only provide as much food as they can eat in 2-3 minutes and to feed them 1-2 times a day. Overfeeding can lead to health issues and negatively affect your aquarium’s water quality.

Common Hatchetfish (Gasteropelecus sternicla)

Common hatchetfish, also known as river hatchetfish, are often found in the Amazon River basin, which spans multiple countries including Brazil, Peru, Ecuador, Colombia, and Bolivia.

Typically, the Common Hatchetfish (Gasteropelecus sternicla) are mistakenly sold as Silver Hatchetfish (Gasteropelecus levis), but they are actually two different species of hatchetfish.

Many times, sellers in the aquarium hobby may market them interchangeably or as same species, leading to further confusion.

Appearance and Lifespan of Common Hatchetfish

While the Common Hatchetfish and Silver Hatchetfish share a similar body shape and silvery color, the Common Hatchetfish is generally larger in size compared to the Silver Hatchet, reaching about 2.5 inches in length.

They are also sleeker, with their pectoral fins located on the higher part of their body. Additionally, a dark lateral line is typically more pronounced in the Common Hatchetfish.

In terms of species lifespan, this Common Hatchetfish enjoys about 2 to 5 years in captivity.

Behavioral Patterns of Common Hatchetfish

Another factor that sets apart Common hatchetfish from Silver hatchetfish is its behavior. The river hatchetfish are often less timid, and instead of chasing their prey, they stalk it!

Now when they get the chance, they capture their meals with great precision. This precision is mostly attributed to their exceptional vision.

Diet of Common Hatchetfish

Adding to the many similarities between Common Hatchetfish and Silver Hatchetfish, they feed on almost the same variety of food.

In captivity, these carnivorous fish readily accept high-quality fish flakes, tiny pellets, as well as live and frozen foods such as brine shrimp and pinhead crickets.

Remember, these fish prefer to eat at the water surface, so it’s important to choose food that floats or stays at the surface long enough for them to consume.

Marbled Hatchetfish (Carnegiella strigata)

Although the name may lead to confusion, the Marbled Hatchetfish, not the Common Hatchetfish, is actually the most frequently encountered type of Hatchetfish in home aquariums.

Appearance and Lifespan of Marbled Hatchetfish

The Marbled Hatchetfish is distinguishable by its characteristic marbled color pattern, which is a beautiful blend of silver and dark shades, creating an effect akin to camouflage. This pattern makes these fish particularly striking in a well-planted community tank.

As mentioned, it is smaller than the Common hatchetfish and Silver hatchetfish, growing to only about 1.75 inches with a life expectancy of only about 2 years.

Like the other species, the Marbled Hatchetfish boasts the signature hatchet-shaped body, allowing it to remain near the water surface to access atmospheric air.

Behavioral Patterns of Marbled Hatchetfish

These commonly wild-caught fish aren’t just strong swimmers—they are perhaps the best jumpers among all the hatchetfish species.

This impressive jumping ability is a natural defense mechanism against predators, but it can pose a challenge for aquarium hobbyists. Thus, covering the tank with a tight-fitting lid is a must!

They are also known to be a little more timid than some other species, so it’s crucial to provide plenty of hiding spots to make them feel secure as they spend most of their time near the surface, often among floating plants.

And while Marbled Hatchetfish may enjoy the company of their kind, they are noticeably more territorial than other Hatchetfish species. If kept in a school, they require ample space to establish their individual territories to avoid aggressive behaviors.

As long as they are not crowded and their tank mates are not aggressive fish or significantly larger, they should coexist peacefully in a mature tank.

Diet for Marbled Hatchetfish

What sets the Marbled Hatchetfish apart from its relatives is its omnivorous diet.

In addition to small insects and zooplankton, the Marbled Hatchetfish indulges in algae and plant matter as part of its diet.

This broader diet makes them slightly different from the carnivorous preference of the other species.

Like other hatchetfish, they thrive on a diet of live or frozen foods such as brine shrimp, bloodworms, protein flakes, and vinegar flies.

As always, make sure that the food stays afloat for a couple of minutes to ensure that the Hatchetfish eats.

Blackwing Hatchetfish (Carnegiella marthae)

The Amazon River Basin, which spans multiple countries like Colombia and Venezuela, is home to many hatchetfish species, including the Blackwing Hatchetfish.

They enjoy slow-moving water and gentle currents, so it’s best to minimize aeration and maximize the use of floating vegetation.

Appearance and Lifespan of Blackwing Hatchetfish

The Blackwing Hatchetfish stands out as the smallest member of the hatchetfish family, reaching a maximum length of just around 1.25 inches. This species settles for a few years of delightful company, with about a 4-year lifespan.

They have a dark coloration that gives them their name, with a silver body that glistens under aquarium lights. Their bodies share the same hatchet shape as other hatchetfish, with the largest part of their body being where their pectoral fins are attached.

Behavioral Patterns of Blackwing Hatchetfish

Unlike Marbled hatchetfish which need lots of swimming space, Blackwing hatchetfish are not that active, so they don’t necessarily need that much space.

And because they are native to heavily vegetated areas, they get easily frightened by aggressive tankmates. So if you decide to get one, adding floating plants will significantly help them thrive and be at their natural behavior.

Note: The hatchetfish are of a size that makes them unappealing as prey, and they are unlikely to interact closely with your angelfish, ensuring mutual avoidance between the two species.

Diet for Blackwing Hatchetfish


Understanding the diet Blackwing Hatchetfish require is essential for their health and longevity. Unlike its relatives, the Blackwing Hatchet is notably more carnivorous in its feeding habits.

This species particularly relishes live foods such as bloodworms and vinegar flies, and they will eagerly snap up tiny fish or insects that venture too close to the surface of the water.

Blackwing Hatchetfish can also be fed a diet of fish flakes, supplemented occasionally with freeze-dried foods.

These dietary habits, more carnivorous than those of other hatchetfish, reflect their predatory lifestyle in the wild. Despite their small size, Blackwing Hatchetfish are active fish with an appetite to match.

Common Health Problems and How to Prevent Them

Disease-Treatment Your hatchetfish’s health relies on its environment. It’s just like us humans, right? Good food, clean living conditions, and low stress – all these make a big difference!

Now, hatchetfish can get the ich parasite, a pesky critter that’s not uncommon among tropical fish. The giveaway? White spots on your fish. A little like fish acne!

But don’t worry, maintaining a clean tank and separating sick fish can halt it in its tracks. You may also find treatments:

Other potential culprits in the hatchetfish world are fungal and bacterial infections, treatment here: 

They can cause fuzzy spots or even sores on your fish. However, a clean tank and well-fed fish reduce the risk of these.

Parasites too can bug your hatchetfish, making them act a bit strange or lose weight. Be it external or internal, a balanced diet with high-quality foods keeps their immune system strong and ready to fend off these pests.

For treatment, see here:

Remember, a happy fish is a healthy fish! Keeping the water parameters right (like temperature, pH, and hardness) can greatly boost the health and lifespan of your hatchetfish, be it Silver Hatchetfish or the more aggressive Marbled Hatchetfish.

Breeding Hatchetfish

Most species, like the Common Hatchetfish, have been proven challenging to breed in captivity, leaving us to marvel at their secretive love lives in the wild.

Yet, one brave soul, the Marbled Hatchetfish, has been known to spawn in the cozy confines of an aquarium.

Interestingly, the Marbled Hatchetfish, which we know has been bred in aquariums, does not necessarily lay fish eggs in a specific location. Instead, the fish eggs are scattered around and often end up among floating vegetation in the tank.

When it comes to encouraging these floating wonders to reproduce, there are a few tricks you can try.

A larger tank is usually more effective for breeding, as it allows the hatchetfish to establish territories and engage in natural behaviors.

Water conditions are also crucial. Particularly with Marbled Hatchetfish, the water’s pH level should be on the softer and more acidic side, typically between 5.5 and 6.5, mimicking the soft water of their native South American rivers and encouraging spawning.

FAQ Section

This section will serve to answer some of the frequently asked questions about hatchetfish care, using more of our designated keywords, and addressing common concerns that prospective hatchetfish owners might have.

1. What do hatchetfish eat?

Hatchetfish are predominantly carnivores and have a preference for small invertebrates. They can be fed a diet of fish flakes, brine shrimp, and even mosquito larvae.

2. Are hatchetfish suitable for beginners?

While hatchetfish do have specific care requirements, with research and commitment, a beginner in the aquarium hobby could certainly care for them. Their peaceful nature and compatibility with other fish species make them an appealing choice.

3. What tank conditions do silver hatchetfish require?

Maintaining optimal tank conditions Silver Hatchetfish require, such as warm water and soft acidity, is essential for their health and well-being. Silver hatchetfish thrive in water temperatures between 75-80 degrees Fahrenheit, with a pH between 6.0 and 7.5. They need a minimum tank size of 15 to 20 gallons, fitted with a tightly covered lid as they are known to be excellent jumpers.

4. Can different species of hatchetfish live together?

Yes, different species of hatchetfish can usually coexist peacefully in the same tank. However, the marbled hatchetfish can be a bit territorial compared to other hatchet species, so choose tank mates for them more carefully and monitor them for signs of aggression.

5. How do I keep my tank clean for my hatchetfish?

Maintaining water quality is key for the health of your hatchetfish. Regular water changes, monitoring water parameters, and having a good filtration system are crucial. Furthermore, avoid overfeeding as it leads to waste buildup.

Remember, with the right care and environment, your hatchetfish can lead a healthy, thriving life in your home aquarium. Happy fishkeeping!


Whether you’re a beginner or a seasoned hobbyist, keeping these unique aquatic creatures offers invaluable insight into their captivating world. Despite the challenges, maintaining a thriving hatchetfish tank provides a rewarding experience and a window into a slice of nature.

Remember, an aquarium is more than a container of water and fish; it’s a carefully curated, vibrant ecosystem. With patience and commitment, your hatchetfish can not only survive but flourish, becoming a lively addition to your space.

So here’s to the wonderful journey of hatchetfish keeping! As custodians of their underwater world, let’s ensure they enjoy a healthy, fulfilling life.


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