Also called poriferans, they have pores or openings all over their bodies, mostly marine animals with few found in freshwater, the simplest form of animals
Sponges
Spend their lives attached to rocks or underwater surfaces
Some have spicules made of hard minerals that provide rigidity and protection
Sponges without spicules are supported by a network of tough fibers
Filter-feeders
Sponges are not hunters, they obtain nutrients by filtering the water that passes through their pores
