What are the causes of Ichthyophthirius Multifiliis in fish?

Ich itself is the cause. The disease is usually referred to as ich, ick or whitespot and manifests itself as small (grain of salt) white spots all over the fish. Ichthyophthirius multifiliis is the Latin name for the parasite that causes this disease. It frequently appears when fish are stressed, such as when the tank is not properly cycled and there is a trace of ammonia in their water, when they are exposed to incorrect temperature, pH or temperature fluctuations, overcrowding, underfeeding or similar stresses. In the established home aquarium, ich usually occurs when a new fish from a stressful environment (such as a bad pet store) is introduced without the proper quarantine period being observed. There are many methods of treating ich, including salt and high temperatures, and commercial remedies based on malachite green, methlyene blue and formalin.