Pond Boss Forums GENERAL QUESTIONS Help Bluegill with half their body missing ??

I have a new pond. @ 3/4 acres stocked with CNBG (600) RES (300) and a few pounds of FHM. I found about 10 bluegill missing the back 1/3rd of their bodies. I have no clue what caused this. Predator? I did throw a cup full of fish food out their for the first time the day before.