Final answer:
Sponges employ filter feeding, in which water is drawn through their pores and microscopic food particles are trapped by choanocytes. The particles are then ingested by phagocytosis.
Step-by-step explanation:
The feeding method employed by sponges is known as filter feeding. Sponges have tiny pores in their outer walls called ostia, through which water is drawn. The water flows through the sponge, and specialized cells called choanocytes filter out microscopic food particles by trapping them in their collar, which is made up of microvilli. These food particles are then ingested by phagocytosis. The beating of flagella from the choanocytes creates a directed water current through the sponge to facilitate the feeding process. These specialized cells trap food particles in mucus, engulf them, and digest them intracellularly through the process of phagocytosis. Through this method, sponges efficiently filter nutrients from the water while they remain stationary in their habitats.