Hatchetfish in Aquaria
The river hatchetfish is a schooling species best kept in groups of five or more that spends most of its time in the top-level of the water where it searches for food. These fish are peaceful towards other fishes, but frequently bicker among themselves. Typical lifespan in captivity is around five years. They come from streams in a tropical climate and prefer water at pH 6-7, a water hardness of up to 15.0 dGH, and an ideal temperature range of (23-27 °C (73-81 °F) . As carnivores, they will readily eat many types of small annelid worms, insects, and crustaceans, and they will also eat standard flake foods. They have a reputation for being greedy fish.
Because of their natural tendency to jump when alarmed, they may jump out of aquarium tanks. To prevent this, the top must either be completely sealed, or the water level lowered so the edges of the tank extend further upwards than the fish are capable of jumping.
Read more about this topic: Common Hatchetfish