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. The top-dwelling, nano fish is unique in its appearance. There are large schools of them swimming just below 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 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 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)

Some species, such as the common hatchetfish, can now be raised in tanks or captives. However, the majority of hatchetfishes are wild caught. The hatchetfish may have been transported from the wholesaler to the store without proper nutrition, which can make them more vulnerable to diseases. 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 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. 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

Because they live in areas that experience flooding and rainy seasons every year, the pH, GH and other parameters of water can be varied for Hatchetfish. They are tropical animals that thrive in temperatures between 75-80degF (24-27degC). 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 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 fish are compatible with hatchetfish? Avoid hatchetfish being kept with large, aggressive fish. They thrive with peaceful tank mates, such as corydoras catfish and tetras. 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

Underfeeding hatchetfish is a major problem for fishkeepers, particularly as they grow in size. This is because they prefer eating from the water surface and are not interested in swimming down to sink food. They feed on insects and zooplankton in the wild using their small, upward-facing teeth. 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’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.