ok you got him eatin thats great!
now let him get hungry (4-6 days) sounds mean but let him be
then stick the silver side on a feeding stick. just act like the fish is swimmin up to him and see what he does.
If he dosent take it at first move it like its goin to swim to the right then left. If your lion still dosnt take it, just wait until hes hungrier
Do not feed your lion anythin else until he eats the silverside.
they learn that if your gonna be reasonable, that they can wait to get what they want