Grantiidae

| name = Grantia | regnum = Animalia | phylum = Porifera | classis = Calcarea | subclassis = Calcaronea | order = Sycettida | familia = Grantiidae | genus Grantia

Grantia are the most primitive multicellular animal. While they consist of eukaryotic cells, they have no tissue or organs. Grantia are hermephrodic meaning they have both male and female reproductive organs. They can reproduce both sexually and asexually. Budding or fragmentation can form a new sponge. Water flows into pores called ostia; the porocyte cells control water flow through the body. With the choanocytes create a current, so the amoebcyte cells can obtain food, digest it, distribute nutrients throughout the body and release waste into the water which leave through the osculum.