I've never seen anyone feed Beardeds feeders before. That's pretty crazy!! I know my Mangrove Monitor gobbles up feeders and snails and misc. mollusks like its going out of style!
You areent supposed to be feeding beardies fish. There is a bacteria in the fish that wil hurt your beardie. I would take him to the vet asap and also invest in the bearded dragon book by healthy happy pet press