Sponges are animals of the phylum Porifera ( /pɒˈrɪfərə/; meaning "pore bearer"). Their bodies consist of jelly-like mesohyl sandwiched between two thin layers of cells. While all animals have unspecialized cells that can transform into specialized cells, sponges are unique in having some specialized cells that can transform into other types, often migrating between the main cell layers and the mesohyl in the process.
