Giant Hatchetfish

Giant Hatchetfish (Thoracocharax securis)

The Giant Hatchetfish is a unique freshwater fish found in the Amazon River Basin and looks strikingly similar to its smaller cousin, the Silver Hatchetfish (Gasteropelecus Levis) and the Common Hatchetfish (Gasteropelecus Sternicla).

They possess a distinct hatchet-like shape, featuring a convex body shape with a fairly straight back and small ventral fins. Its transparent, wing-like pectoral fins often measure up to half of its total body length. Exhibiting silver to white coloration, its back is an olive brown hue. With a small, upturned mouth, the fish displays iridescent green or blue colors depending on the angle of light. A vertical stripe in shades of green to yellow extends from the gill cover to the base of its tail.
They are rarely seen in the aquarium hobby but make fascinating additions to a community tank.

These peaceful fish can grow up to 3.5 to 4 inches in an aquarium setting. A school of at least 8-10 individuals is recommended for their well-being. Several swimming, middle-dwelling community fish can be paired with the timid nature of Giant Hatchetfish. Suitable tank mates include Dwarf Gouramis, Neon Tetras, Rummy Nose Tetras, Harlequin Rasboras, Pencilfish, and Corydoras catfish. It is important to avoid faster swimming fish like Danios or Barbs, as they may outcompete the Giant Hatchetfish for food and cause unnecessary stress.

Giant Hatchetfish prefers a diet of small insects, zooplankton, and other tiny invertebrates. High-quality flake food, micro-floating pellets, live or frozen daphnia, and brine shrimp can also be provided.

To create an ideal habitat for Giant Hatchetfish, they require a well-planted aquarium with floating plants and dim lighting, mimicking their natural environment. A slow to moderate water flow is preferred, with the addition of an airstone ensuring they have access to sufficient dissolved oxygen in their environment.

The minimum recommended aquarium size for this species is 50 gallons, considering their larger size compared to other Hatchetfish. Maintain a gentle to moderate water flow, with a temperature range of 73-86°F (23-30°C), a pH of 5.8 to 7.5, and a hardness of 4-15 dGH.
A secure lid is necessary, as these fish are known to glide up to 9 feet out of the water.