The Green finger Sponge- scientific name, Iotrochota Birotulata - is a species of sponge that dwells in the shallow waters of the Caribbean. This species is called a demosponge which is the largest class in the Porifera phylum. These specific sponges have “skeletons” made of spicules. Spicules are structural elements that protect sponges from predators. This type of sponge has no nervous system and relies on the flow of water for everything. This includes getting food, moving, adjusting to its environment, breathing and things along those lines.