baby guppies, blood worms, small crickets, small chopped up market prawns (if it accepts it now), and maybe pellets if it takes that too. theres a lot of stuff you can feed them and would be a good idea to train them at a small age on what you want them to eat
def. offer a variety. mine love FD krill and small crickets the most. i would try avoiding live feeders unless you raise your own or quarentine them and gut load them.