I had this Exquisite Fairy for the last 9 months. He grew from an emaciated 1.25 inch female to about 2 inches beautiful male. Healthy and fat. However, he had a small dimple on his side when i first got him. This come to a head and ruptured. Over the last 3 months, the ulcer does not get larger but does not heal either. What is it? Is it a parasite? What can I do for him? Fortunately this does not seem to spread to any of my other fishes. I do have cleaner shrimps in the tank but they font seem to clean this wound or ulcer.