Yellow Grub Anchor Worm Anchor worms are parasites that embed into the muscle of a fish's body, and can cause weight loss and death.
Anchor worms are often a problem in outdoor ponds during the summer.
The juvenile stages of the parasite can live outside a host for more than five days. Recently imported fish often carry the parasite. Treatment Anchor worms can be contained using an organophosphorous insecticide such as metriphonate, a treatment that kills the free-living juvenile parasites. The adult parasite should be removed from the fish's body manually with forceps. Once the worm is removed, swab the parasitic area with antiseptic or mercurochrome.