Species NameGasteropelecidae (Note: This is the family name; there are several species of freshwater hatchetfish.)
Common NameHatchetfish
Care LevelIntermediate
Lifespan5-7 years
Adult Size1-3.5 inches (depending on the species)
Minimum Tank Size20 gallons (76 liters)
Temperature72°F – 81°F (22°C – 27°C)
Water ConditionspH 6.0-7.5, Soft to moderately hard water

About the Hatchetfish – Species Summary

Hatchetfish are known for their unique, hatchet-shaped bodies, which have made them a popular choice among aquarium enthusiasts looking for distinctive freshwater fish. Originating from the slow-moving waters of Central and South America, the freshwater species belong to the Gasteropelecidae family. They are most notable for their specialized pectoral muscles, which allow them to be strong jumpers and occasionally glide above the water’s surface, mimicking a flying fish in nature. The combination of their fascinating behavior, engaging appearance, and peaceful temperament makes them an interesting addition to community aquariums.

Hatchetfish Lifespan

The average lifespan of hatchetfish in a well-maintained aquarium ranges between 5 to 7 years. As with most fish species, their lifespan is significantly influenced by the quality of care, environment, and diet they receive. Ensuring consistent water parameters and a balanced diet can help prolong their life in captivity.


The hatchetfish earns its common name from the pronounced, hatchet-like shape of its body, especially the chest region. This unique structure is due to the enlarged pectoral muscles, which give it its strong jumping and gliding capabilities. Depending on the specific species, the coloration can range from silver to bronze shades. Their large eyes, adapted for their dim natural habitats, add to their distinctive appearance.

Average Size

Most species of freshwater hatchetfish grow between 1 to 3.5 inches in length. The actual size can vary depending on the specific species and the conditions of their environment.

Hatchetfish Care

Tank Size

A minimum tank size of 20 gallons (76 liters) is recommended for hatchetfish. Considering their active swimming patterns and the fact that they thrive best in schools, a spacious environment is crucial to mimic their natural habitat.

How To Set Up Their Tank

Recreate a natural environment by incorporating a soft substrate, driftwood, and live plants like Amazon swords or Java ferns, which offer refuge and mimic the dense foliage of their wild habitats. As these fish are known jumpers, a well-fitted aquarium lid is essential to prevent escape.

Lighting Requirements

Hatchetfish are used to shaded environments, provided by canopy layers in their natural habitat. Thus, a moderate to dim lighting condition is ideal for them in captivity. Using floating plants can further help in diffusing overhead lighting, creating a serene ambiance.


Hatchetfish prefer slightly acidic to neutral water, with a pH range of 6.0 to 7.5. It’s crucial to maintain stability in pH levels, avoiding sudden spikes or drops.


Maintain a temperature range between 72°F and 81°F (22°C – 27°C) for hatchetfish. Consistency in temperature ensures their health and well-being.

Water Parameters

Soft to moderately hard water is ideal. Regular water changes, preferably weekly, can help keep water conditions optimal and reduce the build-up of contaminants.

Disease Potential

Hatchetfish are susceptible to common freshwater fish ailments, including ich, fin rot, and parasitic infections. It’s essential to quarantine any new fish before introducing them to the main tank to prevent potential disease spread.

Food & Diet

Being omnivorous, hatchetfish thrive on a varied diet. While high-quality flake or pellet food can serve as their primary diet, it’s beneficial to supplement this with live or frozen foods such as daphnia, brine shrimp, and bloodworms. They also enjoy plant matter, making spirulina a good supplement.

Behavior and Temperament

Peaceful and social, hatchetfish are schooling fish, meaning they prefer to be in groups. A school of 5 or more is recommended. They primarily occupy the top layer of the water column. Due to their strong jumping tendencies, especially when startled, a secure lid is a must-have for any tank housing them.

Tank Mates

Being peaceful in nature, hatchetfish can coexist with a wide range of non-aggressive fish. Ideal tank mates include tetras, rasboras, and small catfish. It’s always wise to monitor any new introductions to ensure harmony within the tank environment.


Breeding hatchetfish in captivity can be a challenging endeavor due to their specific requirements. However, with the right conditions, it’s achievable. The key is mimicking their natural breeding grounds — soft, acidic water with a lower water level and dense vegetation. Once eggs are laid on plant leaves, it’s recommended to separate the adults, as they might consume the eggs. After hatching, the fry can be fed infusoria or finely ground flake food until they grow larger.

Hatchetfish FAQs (Frequently Asked Questions)