I just went through this a couple weeks ago, I got a small Rectic like you have and tried everything, black worms were like crack to that thing! I used red wigglers and cut up other worms, it wouldn't even attempt to eat them, but once I put blackworms in there, it ate every last one! They are disgusting and stink to high hell, but the rays love them! The only other food I have gotten a Rectic to take early on, other than blackworms, is ghost shrimp. They love them too, good luck!