Jonahs Aquarium or Sachs Aquaculture usually have mosquitofish......guppies if quarantined would work just as well. If you put some driftwood and javamoss in a 20g and a half a dozen mosquitofish they will breed on their own and keep your Flathead fed until he gets a couple of feet long (if you supplement with thawed out krill and shrimp and quarantined rosy reds from a bait shop....I cant stress how important it is to make sure you quarantine them to guard against parasites), if the tank temps and food are kept correctly. Flatheads also eat crawdads or shrimp (and anything else they can fit in their mouths) so you might look into a small 10g to breed shrimp in to feed to him also (keeps him healthy if his diet is varied),,,,,,keep us posted and good luck !
