a good variety - shrimp/krill/fish/cat, dogfood (just a little)/fish pellets/mynah bird pellets/earthworms/mealworms... just a wide variety. Heck, even the rare frozen mouse.
regarding pellets, the hikari sinking carnivore pellets are a good (and complete choice), just break them apart into smaller pieces so the lungfish will be able to take them down.
for max growth, a variety is good, but i have found that a staple of the hikari pellets, and chopped raw/cooked shrimp and raw fish work very well. another thing to keep growth rate high is to increase the water temp to about 82F, and increase water changes in both frequency and volume. if you want to really see your lungfish take off, keep up with the feeding, and change 50% of the water every other day or every day if you have the time!--
--solomon
Hmm... I'll have to try the (dry?) cat food.
(My cats might complain a bit, tough.)
I've found my SAL to be a bit of a picky eater, however.
He'll eat anything once or twice, but the only things he'll eat every single time are earthworms and shrimp. Everything else must be spaced out every 5 or six feedings, or it will just sit there untouched. (He will eat algae and/or carnivore pellets, if offered.) I've tried spacing out the feeding times by a day or two, or more, and had no luck in getting him to touch other food items if they are fed repeatedly. I can switch food items, and those will get "sniffed" and then eaten but if it's the same as last feeding time, then forget it. Not even my cats are that picky.