Understand that sponges are simple aquatic animals that belong to the phylum Porifera.
Recognize that sponges lack complex tissues and organs, which means they do not have a digestive system like other animals.
Learn that sponges obtain their food through a process called filter feeding, which involves drawing water through their porous bodies.
Identify that the water enters through tiny openings called ostia, flows through the sponge's internal canal system, and exits through a larger opening called the osculum.
Note that as water passes through the sponge, specialized cells called choanocytes trap and ingest small particles of food, such as bacteria and plankton, from the water.