Large numbers of lernaeids in copepodid stages can kill small fish by damaging their gills and making it hard for the fish to breathe. When female parasites attach to the fish, they burrow deep into the tissues and eventually embed an anterior anchor into the fish's body.

Are anchor worms harmful to fish?

Anchor worms are very irritating to fish and can cause secondary infections. However, they are easily diagnosed and can be treated simply. Aquatic vets usually combine treatment of the aquatic environment with manual removal of the worms while the fish is under sedation.

What do I do if my fish has anchor worms?

Once anchor worms are present on your fish, it is very tempting to simply pull them off, but resist the urge to do so. Anchor worms need to be removed correctly with a fish under sedation by your veterinarian. They will need to remove the entire parasite including the feeding end from under the fish's skin.