Pygmy hatchetfish

Care at a glance

Overview

Peaceful and strictly a schooling fish, so keep six or more, ideally more, in a tank of around 100 liters with a lot of surface area. They stay at the very top of the water. Keep them in the low to mid 20s C with a pH from about 5.5 to 7. They feed at the surface, so offer small floating foods, crushed flake, and small live or frozen items like fruit flies and mosquito larvae. Pair them only with peaceful fish that use the lower levels.

In the wild

Pygmy hatchetfish come from slow streams and shallow, tannin-stained waters in Peru and Bolivia, usually under floating plants. The water is soft and acidic. Give them a tank with surface cover, calm flow, and a tight lid. They sit right at the top, so floating plants make them feel secure.

Good to know

This tiny fish is in the family Gasteropelecidae, the freshwater hatchetfishes, and reaches about 2.5 cm. The deep, keel-like chest houses strong muscles that power the pectoral fins. It is an egg scatterer with no parental care, and aquarium breeding is rarely recorded. It is listed as least concern.

Did you know

Hatchetfish are the closest thing to a flying fish in the hobby. They beat their wing-like pectoral fins to skim and leap across the surface after insects or away from danger, so a fully covered tank with no gaps is a must.

Related species

• 

  Blackwing hatchetfish

  Carnegiella marthae

  1.4 in (3.5 cm)30 gal (115 L)68–82°F (20–28°C)

• 

  Marbled hatchetfish

  Carnegiella strigata

  1.6 in (4 cm)32 gal (120 L)68–82°F (20–28°C)

• 

  Common hatchetfish

  Gasteropelecus sternicla

  1.6 in (4 cm)33 gal (125 L)68–82°F (20–28°C)

• 

  Spotfin hatchetfish

  Thoracocharax stellatus

  3.5 in (9 cm)26 gal (100 L)73–82°F (23–28°C)

• 

  Spotted hatchetfish

  Gasteropelecus maculatus

  3.5 in (9 cm)26 gal (100 L)73–82°F (23–28°C)

• 

  Clown Killifish

  Epiplatys annulatus

  1.4 in (3.5 cm)15 gal (55 L)68–79°F (20–26°C)