Why don't fish have hair follicles? This is because their skin is constructed to make scales. In addition, they lack the cellular machinery that is found in mammals that creates all of the structures of hair follicles. Here, we collaborated with Dr. Michael Phelps (not the swimmer), who studies aquatic molecular physiology to understand the histological nature of trout skin. This is a herovicci stain of adult trout skin performed by Sydney, Nicole, Matteo, and Violet.