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. Enter the hatchetfish. 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. These fish require special care, so let us take a closer look at these fascinating oddities.

What is a Hatchetfish?

Freshwater hatchetfish come from the Gasteropelecidae family and are distantly related to tetras. They are found in South and Central America. Their body is hatchet-shaped and their pectoral fins extend out like bird wings. Their strong pectoral muscles enable the hatchetfish to jump several inches out of the water, allowing them to quickly escape predators.

What types of hatchet fish are available? There are many species that are available at your local fish store, though they may not be in stock. 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 sevis – Common hatchetfish — Spotted hatchetfish Gasteropelecus maculatus – Platinum and spotfin hatchetfish _Thoracocharax

Marbled hatchetfish (Carnegiella strigata)

Although some species, like the common hatchetfish can be kept in tanks or cages, many hatchetfishes were caught wild. The hatchetfish may have been transported from the wholesaler to the store without proper nutrition, which can make them more vulnerable to diseases. Before making a purchase, ask the fish shop how long they have had the hatchetfish. Also, observe how they eat and their behavior.

We strongly recommend that you quarantine hatchetfish and feed them high-quality foods. If possible, use the trio of quarantine medication to treat them. 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

Because their habitat is subject to flooding and rainy seasons, Hatchetfish can survive in a variety of pH and GH levels. They are tropical animals that thrive in temperatures between 75-80degF (24-27degC). As a schooling fish, they need to be in a big group of at least 6-12 fish of the same species. A school of fish will make them feel more secure and allow them to display their natural behavior. 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 should have a tight fitting lid or hood. They will jump out of any narrow slot they 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 do best with tank mates that are similar-sized and peaceful, such as tetras and corydoras catfish. South American dwarf cichlids like German blue rams and Apistogramma cichlids are also fine because they occupy the lower half of the tank, while hatchetfish stay up above.

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. In the wild, they use their small, upward-facing mouths to feed on insects and zooplankton. Therefore, feed tiny foods that float for a long time, and decrease water flow near the surface so the food won’t sink as quickly. 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 will try the incredible hatchetfish and enjoy its 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.