They will only sometimes eat the fry. Most often some will survive. I have mine in a guppy and platy tank and about half of the the fry survive. (Both types)
Edit: fish store people generally dont know very much about fish, their compatibility, or their care. Most of us on here learned that the hard way. Resulting in sick fish, population explosions and worse
Edit: fish store people generally dont know very much about fish, their compatibility, or their care. Most of us on here learned that the hard way. Resulting in sick fish, population explosions and worse