1. Stage 1: Multicellularity
Phyla Poriffera

2. A. The Sponges 1. These organisms… are hetrotrophic
have eukaryotic cells
have organized cells
lack cell walls
species in 3 classes: (classified by
spicule type)
Demospongia (spongin)
Hyalospongia (silica)
Sclerospongia (calcium)
3. All are marine and the adults are sessile
(non-moving).

3. B. Structure and Function
1. A mass of specialized cells embedded in a gel-like structure called matrix. 2. Shape is determined by the environment and spicule type. 3. Cell recognition: sponge cells can chemically “recognize” each other. Used for repair and reproduction for farming. 4. Cell Types:

4. C. Niche 1. Suspension / Filter Feeder a. Extra-cellular digestion
b. One cubic centimeter of (leuconoid) sponge can filter more than 5 gallons of water per day.
2. Compete with other sessile animals for space and food.
3. Many symbiotic relationships.
4. Spicules and toxins deter most predators.
5. Recycle calcium into environment by decomposing coral and mollusk shells.

5. D. Showcase System: Reproduction
1. Asexual (cloning)
a. Budding – small buds extend out and break off.
b. Fragmentation – pieces break off and continue to grow.
c. Self Insemination – injection of sperm into self (see stage 3 flatworms).
2. Sexual
a. Hermaphroditic – produce both male and female gametes but at different times.
b. Gametes develop within the matrix and released through the osculum.

6. E. Strange but true!
Until 1765 no one thought that sponges were animals. It took scientists until 1825 to prove that they are.
If conditions become too bad, clusters of sponge cells will develop a protective coating trapping food inside. These clusters (called gemmules) can survive even if the rest of the sponge dies. When conditions improve they will grow into new sponges.

7. Systems / phyla symmetry feeding digestion circulation movement respiration excretion reproduction nervous # of cell layers/ # of body openings
Poriffera
asymetrical
filter
extracellular
diffusion
planktar or sessile
budding or sexual
none
0 / NA