Lions are some of the best pets in the saltwater side of things in my mind. Didnt have any fish ever that came close to the lion. Groupers, triggers, puffers...nothing was as friendly and loving as my lion. As far as the feeding goes, offer him lots of things, including live food if possible. Once lions learn to eat they are little piggies. Just make sure theres nothing in the tank that will harass them as their long finage not only makes them an easy target, but it also makes it harder for them to get away.