Marbled hatchetfish

Care at a glance

Overview

Keep them in a group of at least six. They are peaceful and spend their time hugging the surface. They take food from the top, so floating flakes, micro-pellets, and small live or frozen foods like mosquito larvae and fruit flies work well. Soft, warm, acidic water suits them. They pair fine with calm mid- and bottom-dwelling tankmates that share the same soft-water needs. A 120 liter tank gives them room to move.

In the wild

Marbled hatchetfish come from slow, shaded streams and tributaries in the Amazon Basin across Brazil, Peru, and Colombia. The water there is soft, acidic, and tea-stained, with floating plants and overhanging cover up top. Match that with a dim, well-planted tank with floating plants, soft acidic water (pH 5.5 to 7), and a tight lid, because these fish live right at the surface.

Good to know

This is a member of Gasteropelecidae, the freshwater hatchetfishes, growing to about 4 cm. The deep, keel-shaped chest houses oversized muscles that power the pectoral fins. They are egg scatterers that give no parental care. The IUCN lists the species as Least Concern.

Did you know

They are true flyers, not just jumpers. Using those big chest muscles they beat their pectoral fins and skim above the surface for a short burst to dodge predators, which is rare among fish and the reason the family carries the hatchet name.

Related species

• 

  Blackwing hatchetfish

  Carnegiella marthae

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

• 

  Pygmy hatchetfish

  Carnegiella myersi

  1 in (2.5 cm)26 gal (100 L)73–79°F (23–26°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)
• Red neon blue-eye

  Pseudomugil luminatus

  1.4 in (3.5 cm)11 gal (40 L)72–81°F (22–27°C)