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 here. This top-dwelling nano fish has a very unique appearance that looks even cooler when you have a large school darting around just beneath the water surface. 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. They can jump several inches from the water’s surface, which allows them to escape predators.

What is the difference between hatchet fish species? Many species can be found in local fish shops, although their availability might vary from season to season. They are usually between 1 and 2.5 inches (2.5-6 cm long), so we have listed them in approximate order from smallest to largest.

– Pygmy hatchetfish, Carnegiella myersi – Blackwing hatchetfish, (Carnegiella marsthae). – Marbled hatchetfish, (Carnegiella strigata). – Silver hatchetfish(Gasteropelecus lavis)- Spotted hatchetfishes (Gasteropelecus makulatus)- – Platinum or spotfin hatchetfishes (Thoracocharaxtellatus).

Marbled hatchetfish (Carnegiella strigata)

Although some species, like the common hatchetfish can be kept in tanks or cages, many hatchetfishes were caught 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. Ask the fish store how long they’ve had the hatchetfish, watch them eat, and observe their behavior before making a purchase.

We recommend that hatchetfish be quarantined, fed high-quality food, and treated with the three quarantine medications. Hatchetfish are prone to ich or white spot disease, which is easily cured with Aquarium Solutions Ich-X. Also, wild-caught fish often have internal parasites like tapeworms, so treat them with Fritz ParaCleanse and then treat them again two weeks later to eliminate any worm eggs that hatched.

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). As a schooling fish, they need to be in a big group of at least 6-12 fish of the same species. The more fish in their school, the safer they feel and the more comfortable they are displaying their natural behaviors. 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 must have a tight-fitting lid or hood because they will jump out of the narrowest slot they can find. You should cover any openings that lead to the heater, filter, or automatic fish feeder with craft mesh.

What fish are compatible with hatchetfish? Avoid hatchetfish being kept with large, aggressive fish. They do best with tank mates that are similar-sized and peaceful, such as tetras and corydoras catfish. South American dwarfs cichlids such as Apistogramma cichlids and German blue Rams are great because they take up the lower part of the tank while hatchetfish stay higher.

What Do 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. They feed on insects and zooplankton in the wild using their small, upward-facing teeth. 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 you’ll enjoy this hatchetfish, and that it will be a delight to watch. For more ideas on other surface dwellers to try, check out our article on the 10 Best Top-Dwelling Fish for Your Aquarium.