Background
This parasite, sometimes referred to as Lernea Elegans, is very common. Unlike most other parasites, Anchor Worm is not related to stress. Anchor Worm is highly contaigious, so the entire tank needs to be treated, not just the fish.
Anchor worm can be intoduced from a newly arriving fish, or as an egg on a plant.
Diagnose
Anchor worm is very visable, so there is no need for a microscope to diagnos the parasite. Anchor Worm, unlike fish lice,does not move around the body of the fish. Fish will flash and scratch when the anchor worm is still in the larvae stage as the parasite has already attached to the fish's body, this will continue in the adult phase.
Treatment
Steps for Treatment:
- Remove anchor worm with tweezers
- Single application of iodine, or hydrogen peroxide, to the spot of worm with a cotton swab.
- Daily applications of neosporin cream.
If the Anchor worm is found on a newly aquired fish that has not been introduced to the community this is probably all that needs to be done. However, if the entire tank is infected additional measures need to be taken. Medications like Dimillin, or Program, might be necessary. Some products, including Anchors Away can be used as Dimillin, or Diflubenzoron, is the main ingredient. Like most things, salt can be a great help also.
Remember that although the visible anchor worm may have been removed, it is most likely that there are larvae still present in the tank. Even before the anchor worm can be seen, damage to the gills and skin of the fish can occur.
From: http://www.desktopgoldfish.com/goldfish-diseases.php?disease=Anchor%20Worm