- Scientific Name: Carnegiella marthae or C. strigata
- Family: Gasteropelecidae within Characidae
- Size: Around 1 to 1½ inches
- Temperature: 74 to 78 degrees Fahrenheit
- Alkalinity: Slightly acidic and moderately soft
- pH: 6.4 to 6.8
- Origin: Amazon and Orinoco basin drainage
The marbled hatchetfish found in the local fish store are all caught in the wild — they have been spawned, but not on a commercial basis. Also, there are at least two species, and probably some others, that come in under the common name of marbled hatchetfish. When it comes to care, the difference of species is not important because the aquarium requirements for all of them are the same.
The first and most important thing to remember about these fish is that they are world class jumpers, and unless the tank is covered tightly they will end up on the floor. At the same time, what makes this a problem is also part of their charm — in that they are one of the few fish that swim almost entirely in the uppermost regions of a tank. And, as you can easily tell from looking at their mouth, they take food exclusively from the surface, although they will take live baby brine shrimp that are just below the surface. Hatchetfish will readily take flake food as long as it floats on the surface of the water. They will relish any small insects you may drop on the water surface (making sure, of course, that the insects have not been exposed to any bug sprays).
The marbled hatchetfish’s tank should have floating plants over as much of the surface as possible. This fish will be much more comfortable if it can hang out under floating plants. Once it has become acclimated, this fish usually does very well, which means it is best that you buy only those that have been doing well in the local fish store’s tanks for a week or more. And, of course, make sure you quarantine this fish before introducing it to your community tank.