You just landed a fish and noticed reddish spots near the tail. While removing the hook, you saw small, black specks around the fish’s mouth. Is my lake sick? How did those slimy critters enter my pond? What can I do?
Those small red spots are symptoms for a parasite—the yellow grub. The black critters are leeches. Both parasites live on or in a “host” before migrating to fish. There are approximately 10 different categories of parasites. Grubs and leeches are most visible. Others are internal and found when cleaning fish. Fish with grubs are safe to eat. Just trim away the affected area and cook thoroughly.
Chemical treatment of parasites can be expensive. A very effective biological management option to control grubs and/or leeches involves stocking redear sunfish. The redear’s common name is “shell cracker”. They have hard plates in their throat that allow them to crunch exoskeletons like snails. Snails are hosts for grubs. By eating snails, redear break the lifecycle of the grub.
Redear may reach 10-inches and provide great fishing action. If you have seen above conditions, stock 150 adult redear per surface acre in lakes with mature largemouth bass. If you’re stocking a new lake, include 250 fingerlings per acre with bluegill and fathead minnows.