What is Porifera?

There are pore bearing animals. It is commonly called sponges. There are the lowest metazoans placed in sub kingdom-- parazoa. So the study of sponges is called parazoology. The animal nature was first recognized by Ellis. But the term "Porifera" was coined by Robert Grant. There are about 5000 species of sponges. These greatly very in their life span and in their size.

Examples:

Scypha ( Sycon ), Grantia, Hylonema, Spongilla etc.