Large barrel sponges are part of the landscape throughout the coral reefs of the Flower Garden Banks. This one is living on the flanks of the East Flower Garden Bank near buoy #2. Sponges are multicellular animals, and they grow in a way that maximizes water flow through their bodies to obtain food and oxygen and to remove wastes. Water is drawn through tiny holes in the sponge walls called incurrent pores. Specialized flagellated cells, called choanocytes, beat and generate water movement. The choanocytes have a collar around them that traps small particles of food. The main channel passing the water out of the sponge is called an excurrent pore. Some sponges can pump up to 50,000 times their own volume in a single day.