What Called Ostia

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. So, the correct answer is ‘Porifera’.

What are Ostia and osculum?

Ostia are the tiny pores present on the surface of sponges, from where water enters and goes to the spongocoel. The osculum is the opening from where the water goes out after passing through the spongocoel.

What are Ostia in biology class 11?

Ostia are minute pores present in the body wall of Sponges (Phylum – Porifera), through which water enters into a central cavity, spongocoel, from where it goes out through the osculum. This pathway of water transport is helpful in food gathering, respiratory exchange and removal of waste.