Porifera
- Sponges and invertabrates
- No symmetry
- No nerves or muscles
- Sessile- do not move
- Filter nutrients from the water that is taken into a central cavity call a spongocoel. The water flows into the spongocoel through pores in the organism.
- Evolved from colonial organisms
- Reproduces asexually by fragmentation
- Reproduces sexually- they are hermaphrodites- each organism has both male and female parts
- Have two cell layers: ectoderm and endoderm that is connected by mesoglea
- Have no true tissues or organs, but have other cells:
- Choanocytes: collar cells that line the body cavity and have flagella that circulate water
- Spicules: functions as support, the substance of the spicules determines the classification of the sponge
- Amoebocytes: cells that move on their own, their functions include reproduction, moving food particles to nonfeeding cells, and the secretion of the spicule material