All fish / Gasteropelecidae

Blackwing hatchetfish

Carnegiella marthae

Also known as black-winged hatchetfish, black wing hatchetfish, blackwing hatchet, marthae hatchetfish, dwarf hatchetfish, black winged hatchet fish, マーサハチェット, 黑翼燕子, 黑翼斧鱼

A tiny hatchetfish with a deep keel-shaped belly, silvery body and a thin dark line along the flank, set off by black-edged pectoral fins and dark markings on the keel. It is kept for its unusual shape and its habit of cruising just under the surface in tight groups, which suits quiet blackwater and planted community tanks.

Care at a glance

Care level

Moderate

Temperament

Peaceful

Adult size

3.5 cm

Temperature

24 to 28 °C

pH

5 to 7

Smallest tank

60 litres

Keep as

Shoal of 8 or more

Diet

Carnivore: small floating insects, fruit flies, daphnia, bloodworm and quality flake

Swims

Top of the tank

Lifespan

3 to 5 years

Water

Freshwater

Wild range

Orinoco, Negro and upper Amazon basins (Venezuela, Colombia, Brazil, Peru, Bolivia)

Breeding

An egg-scattering species that has only rarely been bred in aquariums. Soft, acidic water, plenty of live food and floating plants are thought to help, but most fish in the trade are wild caught.

Good to know

An excellent jumper, so a tight-fitting lid is essential. Wild imports are delicate at first and need soft, clean water and gentle tankmates.