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. However, they have some special care requirements to be aware of, so let’s take a closer look at this interesting oddball.

What is Hatchetfish?

Freshwater hatchetfish come from the Gasteropelecidae family and are distantly related to tetras. They can be found all over South and Central America and are known for having a hatchet-shaped body and pectoral fins that extend out from the body like bird wings. They can jump several inches from the water’s surface, which allows them to escape predators.

What are the different types of hatchet fish? Several species are sold at local fish stores, but their availability may be seasonal. 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 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. They may have been underfed and have a weak immune system by the time they reach the fish shop. 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. Additionally, wild-caught fish are more likely to have internal parasites like tapworms. Treat them with Fritz ParaCleanse first, then treat them again 2 weeks later to get rid of any worm eggs.

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. These tropical animals can live in temperatures between 75-80degF (24 to 27 degC). A schooling fish needs to be with at least 6-12 fish from the same species. A school of fish will make them feel more secure and allow them to display their natural behavior. For example, our CEO Cory McElroy once owned a group of 30 silver hatchetfish, and when they changed directions at the same time, he would see a bright flash of light as their scales reflected like little mirrors.

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 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 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

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. You should feed small foods that float well and reduce water flow to the surface so food doesn’t sink 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 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.