d. low blood sugar by alena
the spicules are the thin and spiny structure that forms the skeleton of a sponge. the spicules provide the structural support and they are small needle-like in a shape. the spicules consist of calcium carbonate and silicon dioxide. it is found in many sponges of the skeleton, they are basically like crystals and they have a pointed and hard and sharp body. like animals, the sponges also posses some sort of skeleton which gives shapes to their body. the skeletal system of the sponge is like a needle or cluster in shape.