Marbled hatchetfish (Carnegiella strigata) care guide

Group
Freshwater fish
Family
Gasteropelecidae (freshwater hatchetfishes)
Origin
Amazon and Orinoco basins in Bolivia, Brazil, Peru and Colombia, and coastal rivers of Guyana and Suriname. Most aquarium fish come from the Rio Negro.
Water
freshwater
Maximum size
3.5 cm
Temperature
20–28°C
pH
4–7
Hardness
Very soft to medium, 1–10 dGH
Minimum tank
68 litres
Care level
intermediate
Temperament
peaceful

Care

A peaceful, gregarious surface-dweller that should be kept in a group of 10 or more; single fish or small groups are nervous. A tank with a base of at least 75 × 30 cm (around 68 litres) is the minimum. A tight-fitting lid is essential: hatchetfish jump when startled and will find any gap. Leave a little air space under the lid. It comes from soft, acidic blackwater, so a heavily planted tank with a dark substrate, floating plants to break up the light and gentle flow suits it best. Aim for about 20–28 °C, pH 4–7 and 1–10 dGH, and add it only to a mature, stable tank. Identification: a tiny fish with a deep, keel-shaped chest and a silvery-gold body covered in a brown marbled pattern. Fish from different areas have slightly different patterns, and several subspecies (such as fasciata) were once named but are now treated as the same species, although genetic work suggests Rio Negro fish may be more than one species. It was once placed in Gasteropelecus. All fish in the trade are wild-caught, mostly from the Rio Negro; it has not been bred commercially. FishBase lists it as Least Concern on the IUCN Red List. Sources: Seriously Fish (seriouslyfish.com/species/carnegiella-strigata/); FishBase (fishbase.se/summary/Carnegiella-strigata.html); Wikipedia (en.wikipedia.org/wiki/Marbledhatchetfish). Checked October 2026.

Diet

Feeds at the surface on small insects, crustaceans and zooplankton. Offer small live and frozen foods such as Artemia nauplii, Daphnia, Moina and grindal worm, plus small floating dried foods. Fruit flies and other small insects are welcome.

Breeding

There are no reliable records of it breeding in aquaria. Females grow larger and rounder than males. In the wild it migrates upstream in the rainy season to feed and spawn, and eggs are reported to hatch in about 36 hours at 25 °C.

Compatibility and tank mates

Very peaceful. Keep with similar-sized calm fish that live lower down, such as small tetras, pencilfish, Corydoras and other small catfish. A good dither fish for dwarf cichlids. Avoid large or boisterous fish and anything that might eat it.

Last updated 5 October 2026. Community-edited care guide on Aquatic-Auctions.

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