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Freshwater Hatchetfish (Gasteropelecidae) Care Guide

When it comes to the beautiful community tank, it is not always about something beautiful and elegant. Many variables can make your aquascape experience more colorful. Adding something unique to your community tank can also enhance your experience as an aquarist.

One of the species that fit the category “unique” is the freshwater hatchetfish (Gasteropelecidae).

The first thing you see this fish, you will be impressed with its awkward and unique look. The triangular shape of the fish is extraordinary. It indeed looks like a hatchet.

Adding this to your home aquarium will create different opportunities to enjoy more time for your hobbies and interests.

The hatchet fish are agile, active, and fun to watch. They love to dart back and forth from corner to corner. They are great swimmers who can go from one point to another in a speedy way.

Don’t get fooled by its small size. They are fast predators who can zap their prey without realizing it. Their game won’t know about their existence until it is too late to learn. They are also excellent jumpers.

One of the most favorite foods is insects. They will come to the area just below the surface to monitor their prey. And when their game is already marked, they will use their wing-like fins to jump off the water and catch the insects.

As I have stated some interesting stuff above, is it intriguing enough for you to want to know more about this particular species? If the answer is yes, let’s just proceed. I will cover everything you need to do to care for and breed them in your home or other places.

Species Overview

Level of CareModerate to difficult
Life Expectancy2-5 years
Size1.25 inches (3.2 cm) to 2.5 inches (6.5 cm)
Tank Size15 gallons
Tank EnvironmentFreshwater with floating plants and rocks
Tank MatesOther small fish

Hatchetfish are native to rivers and wetlands in Central and South America. You can find them in the headwaters of these rivers and marshes. But the wild versions might not be suitable for your current tank.

Their strong fins and hatchet shape make them great swimmers and predators. Even when breeding, they stay near the water’s surface. That could be a pretty bold move made by the parents of the fish. But it is what it is.

Hatchetfish can soar over 4 feet in the wild, which makes pretty sense if they’re able to catch the insects for their dinner. They may try to escape from your home aquarium. Therefore, you will want to provide an adequate tank with lids for them.

Four species of Gasteropelecidae are commonly found in aquariums. The names Silver Hatchetfish (Gasteropelecus levis) and Common Hatchetfish (Gasteropelecus sternicla) are often confused.

The Silver Hatchetfish is the shyest of the bunch. Therefore, one will need to replicate the real environment to make them feel at home and comfortable. It is smaller than the Common Hatchetfish (even when sold as a Silver Hatchetfish) and larger than the Marbled and Blackwing Hatchetfish.

The Silver Hatchetfish can reach 5.08 to 5.72 cm in length and live for three years in captivity.

Their shy characteristics are within their nature. It is not surprising that they constantly look for places to hide when pairs of eyes watch them. In the original habitat, they would hide in the floating plants’ roots. It is imperative to prepare all of the things you need to care for and breed them before finally putting them into your community tank.

When they are transferred to a new living place, they won’t feel nervous for the first time since they feel familiar with the environment. What they want to do first will be seeking the floating plant. If you put the tank mates there, it is important to keep the hides there. They will likely withdraw and find the best place to hide and wait until the situation is calmer.

It is important to know that the hatchetfish friends that you want to pet are not very active. They tend to be passive and hide. But they do this for a good reason. They are stalking their prey. They are so patient. Rather than chasing their prey, they will wait for the right moment to snatch their prey’s life.

Hatchet fish have great quality eyes and a set of skills as mini predators. They will wait near the surface, in between the floating plants, to stalk prey in the top and middle dwellings. But if they are targetting insects, they will use their fins to fly to catch them.

Since they are good jumpers, make sure you set up a tight-fitting lid to prevent them from escaping your aquarium.

Cared for in the maximum conditions, they will be able to live for up to 5 years.

The common hatchetfish has a silver body with a black stripe. As you add these little friends to your community tank, you will see them blinking around your aquarium. It is a fun way to enjoy your leisure time.

Tank Setup

First things first, let me tell you that your hatchetfish buddies are sensitive to ammonia. Therefore, it is much better to prepare your tank first to reach maturity before adding any single fish. Make sure that your tank already has stable parameters.

As mentioned, they mostly spend their time at the top of the aquarium. They can often jump to catch the insects outside the water. Therefore, if you don’t close the aquarium’s lid, they will likely escape for good. These fish are not exactly bottom dwellers. Consequently, you don’t need to plant greens at the bottom unless you add tank mates who need the bottom greenery.

The key to its longevity and healthiness lies in the native environment. They will be happy and well. In good condition, they can live up to five years or more.

Silver Hatchetfish are sensitive to ammonia and other water factors, including pH. Even the slightest ammonia content in your aquarium can be a huge risk for the hatchet. So a robust filter and a clean tank are required. Consider maintaining the cleanliness of the tank regularly. The last thing you want is for your fish to collapse because you are late cleaning the tank.

Remember that even small fluctuations might hurt Silver Hatchetfish, so keep the same levels for the greatest fish health.

The factors that best fit the Silver Hatchetfish’s natural habitat are:

  • pH Levels: 5.8 to 6.9
  • Water Hardness: 2 to 12 dKH
  • Water Temperature: 74 °F to 83 °F (23.3-28.3 °C)

For a group of at least six specimens, you could prepare a 20-gallon tank. Consider upgrading your tank if you want to add more samples to your tank environment.

2 freshwater hatchetfish

Tank Mates

Since Silver Hatchetfish spends most of their time in the upper portion of the tank, they could be placed in a communal tank with bottom dwellers.

Any aggressive or overly energetic fish will stress the Silver Hatchetfish.

Pairing them with aggressive fish threatens the Silver Hatchetfish’s food supply and their overall safety.

Here are the most suitable tank mates for your little buddies:

The small group of six fish is the minimum number you can add for them to thrive. But you can also multiply the numbers since this can enhance their survivability and longevity much better. They are fond of larger groups. It will give them peace of mind and convenience. You don’t want to keep them single since they will be dead sooner.

Do not mix them with aggressive fish since it will only stress them.

If you are only interested in the hatchet, then it will be great. They have higher longevity rates when you put them into a tank dedicated only to this species.

Freshwater hatchetfish front view

Food & Diet

This species is a carnivore. Floating foods favor them. Therefore, you can provide them with some meaty food, including blackworms, blood worms, daphnia, larvae, fruit flies, and so on. You can also add the frozen versions of the foods.

To make their stomachs fuller, you could also combine the meaty protein with the flaked foods.

In the natural habitat, their diet mostly comes from insects. So, you can also focus on insects and larvae since it will make them happier.

In tropical areas, this fish can be a real problem solver for those who have been fighting insects. Having the tanks specifically for the hatchetfish will help you to reduce the annoying insects exponentially.

Gasteropelecidae Breeding Guidelines

It can be hard to distinguish between males and females. They lay the eggs at the bottom of the tank. But it will be hard to breed them in captivity.

There is not much reference that I can take from the experts about generating it. The latest information that I got is that farmers are still developing the technique for producing this species in home aquariums.

Some reports claim that the key to successful breeding is the lower water pH and rich nutrition from insects.