MyFishFinder.com Just like iceshanty but warmer
I seem to recall the wormy perch I've found had black specks on there bellys and when cleaned there were grubs in the meat.now I throw back perch with the spots
The black dots aka black grubs are spread by water birds. They are then spread into water snails, then to fish. Usually the black dots are on the skin- no harm done. Yellow grubs, get spread by water birds as well such as herons, and cormorants. Those usually result with worms in the flesh/meat of the fish.