What are the possible causes of white spots on a black moor goldfish and how can they be treated effectively?

White spots on a black moor goldfish could be caused by a parasitic infection called ich, bacterial infection, or poor water quality. To treat effectively, you can use aquarium salt, raise the water temperature, and use medication specifically for treating ich or bacterial infections. It is important to also improve water quality and maintain a clean environment for the fish. Consulting a veterinarian or a knowledgeable fish expert for proper diagnosis and treatment is recommended.