There is no absolute agreement about the cause of this problem. There are no reported records of it occurring in Aquaculture, yet it is observed frequently in Aquaria. Some of the various theories about the cause are as follows. 1. It is caused by low leakage of electrical current into the aquarium. 2. That the use of various carbon filtration plays a role by somehow interfering in the dietary take up of the fishes food. 3. That there is a lack of certain vitamins in the diet of the fish.
The outlook unless corrective action is taken, is that most fish affected will succumb. It should be noted however that certain species of fish are far more prone, to the ravages of this disease. Those most affected are fish of the Surgeon and Tang Families. Blue Regal Tangs for some unknown reason are the most susceptible, and Yellow Tangs are affected, but the appearance of the problem, and its signs are rather different to each other, though the outcome if untreated is the same.
Before introducing new fish to an aquarium , and especially those species that are know to be prone to this disease, ensure that all the steps related above, have been attended to. Prevention is far better than cure. Also do not purchase any fish that have been less than 2 weeks in the tanks of the vendor.