You don't need a microscope to see Anchor Worm. The adult female which is the only one you'll find on your koi or pond fish (males die shortly after mating) looks like a thread hanging from your koi fish with a pair of egg sacs that are shaped like a "Y" at the end on the body. The head (which has anchors) of the Anchor Worm is imbedded into the body of the koi and pond fish.
The piercing of the skin causes inflammation. However, the biggest threat is, the bacteria infection anchor worm causes leaving a hole in the protective slime coat and skin. These "holes" give the opportunistic bacteria such as Aeromonas or Pseudomonas which are one of the biggest causes of deadly ulcers(body sores) to invade your koi and pond fish. Anchor worm can survive winter conditions as an adult female on your koi or as eggs.