Porifera, meaning "pore bearer," are multi-cellular organisms that have bodies covered in pores. These pores allow for water and other materials to circulate through them.
The Venus Flower Basket, like all porifera, has no urinary system that involves urine, instead, the Venus Flower Basket has a symbiotic relationship with shrimp, in which the shrimp lives inside the Venus Flower Basket and clean it, and the Venus Flower Basket traps waste in its tissue and releases it into its spongocoel, where the shrimp feeds on it.
Glass Sponge
Glass sponges are thought to survive on nutrients that are dissolved in the salt water, and absorb oxygen by diffusion from water into cells. The sponge releases waste through its walls and into the outgoing water current.
Stove-pipe Sponge
The stove-pipe sponge can grow up to five feet tall and survive off of plankton and other small organisms. They regulate their water levels by allowing water to escape through their pores and to enter the same way.