Anchor Worm (Lernea)

Anchor Worm is visible to the naked eye, the adults can reach lengths of up to 12mm.  It attaches itself to the Koi and the the anchor pentrates under the scale and into the muscle where it feeds.  At this point only the tail of the Anchor Worm is left exposed which is said to resemble a length of cotton.  The Anchor Worm has many different life stages, none of which resemble the adult, which you need to be familiar with to be able to recognise them in their juvenile stages.  By penetrating the tissue this parasite is able to cause significant damage and if left untreated secondary infections such as bacteria and fungus, it is these infections that put the Koi at great risk. The Anchor Worm will not leave it's host until it dies.  Fortunately Anchor Worm rarely causes a concern for the hobbiest i,t is usually something dealt with by the dealer as it is more commonly found on newly imported Koi

Any treatment needs to firstly steralize the adults, after reproduction has been stopped all adults must be removed.  Sedation is necessary to perform the delicate proceedure in which the parasites are removed - including the anchor part one by one using a pair of tweezers.  A topical treatment should then be applied to the wound.