- This article is about the skeletal structure. See also Spicule (solar physics) and Spicule (glass manufacture).
Spicules are tiny spike-like structures of diverse origin and function found in many organisms, such as the copulatory spicules of certain nematodes or the grains on the skin of some frogs. In sponges, spicules perform a structural function. Spicules are a very important part of many organisms.