👉 Rhianodes are small, round-shaped structures found in the gut of a fish, particularly in the intestines, that serve as the digestive system's primary storage of nutrients and waste products. They are primarily composed of two parts: the outer layer (the epibenthic) and the inner layer (the subepibenthic). The outer layer is responsible for absorbing food from the water, while the subepibenthic serves to store waste products that can be excreted through