EVERYDAY SCIENCE

Detailed explanation-1: -These pores are sometimes also referred to as ostia, and they provide openings for water, which carries planktonic food and oxygen, to enter the sponge body (Fig. 3.19). Simple vase-like sponges have a single large top opening, called the osculum through which water leaves the sponge.

Detailed explanation-2: -The osculum is a large opening that forms the excretory tract of the sponge. The size of the osculum opening is determined by contractile myocytes as the size regulates the volume of water expelled from the sponge.

Detailed explanation-3: -Sponges have a body wall penetrated by tiny openings, or pores, called. (AHS tee uh), through which water enters. The name of. the phylum, Porifera, refers to this system of pores.

Detailed explanation-4: -Calcareous sponges of the genus Scypha are shaped like tubular sacs, with an opening (osculum) at the tip.

Detailed explanation-5: -Ostia are small holes on the surface of sponges that allow water to enter and exit the spongocoel. Water enters the sponge’s body via the Ostia and travels to the spongocoel and it then exits the body via the osculum.