Our next quite common parasite under discussion is the Anchor worm.


Also known as Lernaea, it is an external parasite which you can view with the naked eye. It is a true parasite in that it lives on the fluids and tissue of the fish itself.

They range from 5 - 13 mm in length and are normally off white or black.

They anchor themself on any part of the koi and in the process puncture or creates a hole in the body. See the image above. This again, creates the possibility of bacterial infection and consequent death.

The koi will move erratically trying to get rid of the worm or flash, and that also creates open wounds and consequent secondary bacterial infection and possible death.

They are quite common on koi which have been harvested recently from mud dams.

Treatment:

First of all, you have to get rid of the worm by gently removing it with tweezers. Then, it is vitally important to sterilize the wound with Potassium, Malachite Green or other suitable topical antiseptic.

Secondly, you have to inspect if bacterial infection were created. If so, you have to treat for bacterial infection first. In a case like this, I personally treat with Potassium, because it will address the bacterial infection and it will sterilize the wound and it is also a bit effective against Anhor worm.

Thirdly you have to get rid of the worm in all its stages. Use Dimilin or Dipterex @ 10 g / 10 000 liters and follow up the treatment after five days to get rid of possible newly hatched worms. It is also a good idea to increase your salt levels to 3kg/1000 liters to prevent infection.

If you treated with Potassium for bacterial infections, do the Dimilin or Dipterex treatment only after the water turned brown from the Potassium and only after a 30 % water change.