It is the name given to a young catfish.
Called fry, then as they grow, fingerlings.
If you mean fingerling fish (young fish the size of a finger), it depends on the species. By the time something like a bass is a fingerling it already wants meat - instects and other fish. You have a hard time keeping preadatory fish from eating each other. Fish like catfish will eat food pellets and algae/bugs. Fish like tilapia will eat algae.
Fingerling
fingerling
Fry or fingerling..
Either fry or fingerling.
fingerling - starplazza
fingerling
A young salmon. See Parr.
A young fish. This term is often used in fish hatcheries.
Most times they are called fry or fingerling
A male catfish