It did not retract and it breaks off through out the tank.... I read somewhere it’s him getting rid of damaged suckers and they do this when they didn’t get enough nutrients.. and won’t survive...Hello I’ve had a chocolate chip a while back and the orange stuff appear to be the stomach. You do know starfish expel their stomachs to eat. They dissolve their food outside their bodies and then sorta mop up the food into them. When I had mine it was to harvest limbs for a harlequin shrimp.
Only big difference from your pic was the stomachs usually stick to the surface it’s on.Not just hang out. When you moved him it should retracted his stomach.
They should be feed meaty foods for sure. And if you don’t plan on having corals totally safe to keep these guys are easy to keep.