Gnathonemus petersi


Junior Poster
Jan 7, 2006
Salt Lake City, UT
Re: Gnathonemus petersi

I’ve kept them. They are perfect for a planted tank; very respectful of the plants. Pros; they are interesting (weird chin thing) and love to zip around the tank playing with the other fish. Mine loved to school with my clown loaches. They fit right into a black water setup and have similar needs as other ‘scaleless’ fish.

Cons; they are notorious jumpers and a complete cover is mandatory, they are ‘scaleless’ and have all the associated problems, you can only keep one adult as they are very territorial (you may notice your store only has juveniles in the same tank), they are agitated by other ‘electrical’ fish, ghosts and so forth.

They are difficult to tend initially. Depending on your local store they may be off their food. Get them feeding again with live feedings (purged and rinsed tubifex work well) in a dim or dark tank. They like a softer substrate to probe for food with their chin. Once back on their food they will take anything frozen, haven’t seen them take dried food. The last one I kept grew to about 8” in a 55gal over six years. I had to put it down after it suffered a broken spine. I have no clue how it happened; I’m guessing a transient short in one of my submersed electricals.

All in all one of my favorites. Feel free to ask me anything; I’ve had good luck with them and loads of experience.

Tom Barr

Staff member
Jan 23, 2005
Re: Gnathonemus petersi

They will eat shrimp and be somewhat belligerent among like fish.
I've kept them for many years and many species within this family.

Tom Barr