I like to feed crickets because they'll eat almost anything. I feed the crickets about one hour before the aro. I give the crickets a varied diet, therefore the aro gets a varied diet. I don't feed any fish(disease, high fat, DE etc.). I also like supplement with whatever I can catch for him. Flys, spiders, moths, small frogs, baby mice. I wouldn't advise mammals and amphibians till the aro gets at least 15 inches. Their digestive systems seem to be a little fragile when young. It's not likely for an arowanna to eat shrimp in the wild. I'd stay away from them.