1. The Porifera (To bear pores)

2. Major Characteristics
Animal Characteristics
Asymmetrical or Radial Symmetry
Cell Specialization without Distinct Tissue or Organ Systems
Non-Mobile adult stage that has a central cavity through which water circulates

3. Body and Cell Types
The sponge brings in water through numerous pores and excretes through a large pore called the osculum
Pinocytes
Amoeboid Mesenchyme Cells
Choanocytes

4. Feeding
As water is drawn in by the flagellated choanocytes nutrient particles get trapped in a ring of microvilli around the flagella
The particles are transferred to the base of the collar where they are take into the cell and digested inside food vacuoles
Nutrients are passed around the sponge by the amoeboid cells

5. Reproduction
Most are monoecious but sperm and egg production usually don’t coincide
Some choanocytes go through meiosis to form sperm or eggs
Sperm are released through the osculum and are trapped by other sponges as in food.
In the mesohyl, the sperm and egg unit forming the zygote
As the zygote develops it becomes a flagellated larva and leaves the parent sponge
Finally, it settles on the ground where it develops into an adult sponge