Both the yellow grub and the more comonly seen black spot (black dot) are clam larvae that travel from
fish eating birds to snails to fish. The black spots are actually the fish's own pigment surrounding the larvae on the skin and in the flesh. I fear that the ever increasing number of cormorants we see in the reservoirs may be contributing to the increase in infection. As posted above, they are harmless to humans
and more of an eye-sore than any threat. They can be found on LMB, SB, yellow perch, bluegills, all warm
water fish.