Clear hatchetfish

Gasteropelecus levis

Also known as Gastropelecus leavis, Smooth hatchetfish

FreshwaterFish

Care at a glance

Temperature: 73–82°F (23–28°C)
pH: 5.5–7.2
Adult size: 1.4 in (3.5 cm)
Minimum tank: 30 gal (112 L)
Temperament: Peaceful
Social behavior: Schooling
Swim level: Top
Difficulty: Medium
Breeding: No record
Rarity: Rare
Origin: Lower Amazon basin, Brazil
Family: Gasteropelecidae

Overview

The clear hatchetfish is a small, peaceful surface fish that lives in schools, so keep at least six and preferably more, since lone fish are nervous and fade quickly. It hangs just under the surface almost all the time, so a wide tank of around 112 liters with plenty of open water at the top suits it, and a tight lid is essential because a startled school will leap clean out of the water. It is completely harmless to tankmates and mixes well with other calm fish such as small tetras, rasboras, and corydoras. Feed floating and surface foods, including small flakes, tiny frozen items, and insects like fruit flies, since it feeds almost entirely from the film.

In the wild

This hatchetfish comes from the lower Amazon basin in Brazil, living in quiet backwaters, creeks, and flooded margins where the surface is shaded and still. The water there is soft and slightly acidic. Recreate it with warm water from 23 to 28 C and a soft, gently acidic to neutral pH between about 5.5 and 7.2. Floating plants, overhanging roots, and a dark substrate make it feel secure and encourage it to stay out in the open, while calm water and a snug cover keep a jumpy surface fish where it belongs.

Good to know

Gasteropelecus levis is a freshwater hatchetfish in the family Gasteropelecidae, one of the smaller silver species at around 3.5 centimeters standard length. Its deep, keeled chest houses the enlarged muscles that power its pectoral fins, and it has a plain, glassy silver body. The name levis means smooth. It is not known to have been bred in the aquarium, and the species is rarely offered for sale, often mixed in with the more common silver hatchetfish.

Did you know

Hatchetfish are strong surface jumpers. Powered by the big muscles in their keeled chest, they beat their wing-like pectoral fins to skitter across the water and launch into short leaps when something startles them.