EVERYDAY SCIENCE

Detailed explanation-1: -Ostia are small pores through which water enters the cavity spogocoel and leaves through the opening called Osculum.

Detailed explanation-2: -Sponges are perforated by many tiny pores called ostia that permit water to enter one or more oscula (singular osculum) that let the water exit. These openings are connected by a series of canals, some of which are lined by collar cells called choanocytes whose flagella maintain a flow of water through the sponge.

Detailed explanation-3: -Ostia are the inhalant pores in the body of sponges. Water enters the body of sponges through ostia and reaches the spongocoel. It then flows out of the body through osculum. Ostia is present only in sponges i.e. phylum Porifera as sponges have a porous body.

Detailed explanation-4: -Water flows through the ostia into the spongocoel and goes out through the osculum. This helps in food gathering, exchange of gases and removal of waste.