Care Guide for Hatchetfish – Oddball Schooling Fish with Wings

Most freshwater fish like to hang out in the lower two-thirds of the aquarium, so it can be hard to fill in the upper third with some activity. The hatchetfish is your answer. The hatchetfish is a top-dwelling nano fish that has an unusual appearance. It can be seen darting about just below the surface of the water. They do have special care requirements, so let’s take an in-depth look at this oddball.

What is a Hatchetfish?

Freshwater hatchetfish come from the Gasteropelecidae family and are distantly related to tetras. They are common in South and Central America. They have a hatchet-shaped body with pectoral fins that extend from the body like bird wings. The hatchetfish’s strong pectoral muscles allow them to leap several inches above the water and escape predators quickly.

What are the different types of hatchet fish? Several species are sold at local fish stores, but their availability may be seasonal. They typically measure between 1-2.5 inches (2.5-6cm) in length, so we listed them roughly in alphabetical order.

– Pygmy hatchetfish (Carnegiella myersi) – Blackwing hatchetfish (Carnegiella marthae) – Marbled hatchetfish (Carnegiella strigata) – Silver hatchetfish (Gasteropelecus levis) – Common hatchetfish (Gasteropelecus sternicla) – Spotted hatchetfish (Gasteropelecus maculatus) – Platinum or spotfin hatchetfish (Thoracocharax stellatus)

Marbled hatchetfish (Carnegiella strigata)

While some species like the common hatchetfish are now available as captive-bred or tank-raised, most hatchetfish are caught from the wild. By the time they travel from the wholesaler to the fish store, they may be underfed with weakened immune systems, making them more susceptible to disease. Before you make a purchase, check with the fish store to see how long the hatchetfish have been in their possession.

We strongly recommend that you always quarantine hatchetfish, feed them lots of high-quality foods, and proactively treat them with the trio of quarantine medications if possible. Hatchetfish are prone to ich or white spot disease, which is easily cured with Aquarium Solutions Ich-X. Wild-caught fish can also be affected by internal parasites such as tapeworms. To eliminate these parasites, treat them with Fritz ParaCleanse, and then again two weeks later.

How to Set Up an Aquarium for Hatchetfish

Hatchetfish can live in a wide range of pH, GH, and other water parameters because their habitat experiences rainy seasons and flooding every year. They are tropical animals and can thrive at temperatures between 75-80degF (24-25 degC). They need to be surrounded by at least 6-12 other schooling fish of the same species in order to thrive as a schooling fish. They feel safer and more comfortable displaying their natural behavior when there are more fish in their school. Cory McElroy was once the CEO of a group that included 30 silver hatchetfish. He would notice a bright flash of light when their scales were reflecting like mirrors as they switched directions.

A school of hatchetfish in a blackwater aquarium

Hatchetfish are not super active, so you can keep them in a 20-gallon aquarium or larger. The tank needs a tight-fitting lid. Hatchetfish will jump out from the narrowest slots they can find. You should cover any openings that lead to the heater, filter, or automatic fish feeder with craft mesh.

What kind of fish can live with hatchetfish? Hatchetfish should not be kept with aggressive fish, large enough for them to eat, or that can outcompete them in terms of food. They are most comfortable with tank mates of similar size and peace, such corydoras catsfish or tetras. South American dwarf cichlids, such as Apistogramma and German blue rams, are fine because they live in the lower half of the tank. Hatchetfish remain up there.

What Does Hatchetfish Eat

Fishkeepers face a problem with hatchetfish as they grow larger. They need to feed them properly because hatchetfish prefer to eat on the surface of the water and don’t like to swim down for sinking food. In the wild, they use their small, upward-facing mouths to feed on insects and zooplankton. To ensure that the food doesn’t sink too quickly, you should give them tiny foods that float. Good floating foods include high-quality flakes, floating pellets, freeze-dried foods, and live baby brine shrimp that tend to swim toward the aquarium light.

Platinum hatchetfish (Thoracocharax stellatus)

We hope that you enjoy the hatchetfish’s unusual appearance and behavior. For more ideas on other surface dwellers to try, check out our article on the 10 Best Top-Dwelling Fish for Your Aquarium.