Ich are a common freshwater parasitic protozoa of the genus Ichthyophthirius. It is also known as White Spot Disease. Ich is ciliated, meaning it is covered in small hair-like appendages called cilia that allow it to swim freely while it searches for a fish to attach itself to. Once attached to a fish’s skin, it forms a tough outer shell to protect it while it feeds on the fish’s bodily fluids. During this time, it grows large enough to be seen with the naked eye. Fish with Ich look like they have tiny white bumps on their skin.