An example of Hexactinellid
Porifera, or "the sponge phylum," lives mostly in marine environments. It's name comes from the Latin roots "porus," which translates to pores, and "ferre," which means to bear. These multicellular organisms technically have no organs, muscles, digestive track or brains. There are three classes, the Hexactinellida, or glass sponges, the Calcarea, or calcareous sponges, the Demospongiae, or demosponges. There are over five thousand different species of Porifera, including Gelliodes Fibrosa, Suberites Zeteki, and Zygomycale Parishii
What Nervous System?
Members of the Porfifera phylum have no nervous system. They have no brain and no nerve cells. They rely on water intake and out put for oxygen intake, waste removal and digestion. They have no reactions towards their physical environments except some species that move across the ocean floor at speeds up to four millimeters per day.