Marthae Hatchetfish

General Information
Scientific Name Carnegiella marthae
Minimum Water Size 10+ gallons (37.75+ liters)
Ease Of Care Advanced
Average Lifespan 7 years
Temperament Peaceful
Approximate Adult Size 2 inches (5.08 centimeters)
Water Parameters 73-81 degrees Fahrenheit (22.80-27.22 degrees Celsius), 2-4 KH, 5.5-6.5 pH
Diet Carnivore
Native Region Venezuela


The hatchetfish is a very interesting and unique fish species that has many features that other fish species do not. One feature that only Hatchetfish have include long thin fins that are used to propel it outside of the water and be able to fly through the air to catch it's prey, very thin and sleek bodies in order to aid in them flying through the air, and also the fact that they have a very long round body shape. One requirement when keeping any form of hatchetfish is to have a hood or lid covering all portions of their setup, as they will jump when they feel threatened from below or if they see any movement above the water's surface.

The hachetfish is a schooling fish that requires a minimum of 8 (eight) of it's own kind in order to feel safe and secure. They will normally be found near the water's surface or swimming in the middle to top zones of the water column. Hatchetfish are extremely peacefully shy fish that should not be kept with any aggressive or passive-aggressive fish in the same water. Due to their thin bodies they are more prone to get blown around by water currents even near the surface of the water as they come from very slow moving streams in their natural environment.


There are very rare occurences of hatchetfish breeding readily inside of any environment unless given the correct conditions to make them breed. Females will have a more plump body appearance when viewed from directly above while the males will have a very thin profile, however they both will display the same colors regardless of their gender. Breedinghas been reportedly stated to only occur in soft, acidic water that has a variety of floating vegetation after they have been feed a diet that is primary of live foods. The eggs will be deposited on the floating vegetation and will hatch around 30 hours later. The fry will be required to be feed off of smaller foods such as infusoria, baby brine shrimps, or possible crushed pellets or flakes that are deposited on the surface of the water.


Hatchetfish will gladly accept any meaty pellet or flake, live or frozen foods, and some might accept any non-meaty form of flake. Since they will only accept food that is floating on the surface, any food that is sinking they will not go after nor eat. Remember that in nature these fish normally will jump (or fly out) of the water to catch their prey, they do not search for food regardless of how close it may be to their mouths of head if it is not on the surface of the water. Due to their delicate nature, they also can be outcompeted for food if enough food is not dropped near or directly over them on the water's surface.