1. Porifera

2. What is a Sponge???

3. Metazoans Multicellular animals (3 grades)
Mesozoa - tiny worm-like parasites, few species
Parazoa - no true germ layers
Placozoa (single species!)
Porifera (the Sponges!)
Eumetazoa – true germ layers, all other phyla!

4. Porifera = Sponges

5. Characteristics Multicellular, loose aggregation of cells
Body of pores, canals, chambers
All aquatic, most marine
No organs or true tissues
Sessile – does not move

6. Unique Cells Choanocytes
Flagellated cells that create current through the sponge
Also used in feeding

7. Structure (skeleton) Spongin Spicules Fibrous protein made of collagen
Skeleton of needle-like spikes
Can be made of calcium, silica or a protein called spongin.

8. Respiration, Circulation, Excretion
Choanocytes
Creates current of water to get oxygen
Get rid of waste from all cells
Ostium
Small intake pores, water goes IN
Osculum
Large opening, water goes OUT

9. Nutrition/Digestion Choanocytes
- use collar to filter out small particles of food
Archeaocytes
- move food around within the sponge
Pinacocytes
Absorbs nutrients

10. Reproduction Both Asexual and Sexual Reproduction
Choanocytes produce eggs and sperm, although not produced at same time. (monoecious)
WHY????
Broken off sponge can produce more sponge
Certain Choanocytes will lose their flagella and undergo meiosis

11. Asexual Reproduction

12. Nervous System No real nervous system.
All instructions are at the cellular level…. nucleus
Each cell only controls itself… No Brain to control all cells

13. Water Flow in a Sponge
Name the cells!

14. Types/Body Shapes of Sponges
Asconoid
Syconoid
Lueconoid

15. Asconoid
one simple canal from pore to central cavity or atrium called the SPONGOCOEL
Small, tube shaped sponges

16. Syconoid
Folded wall with canals from pore to smaller canal that then goes to the larger central cavity (atrium)
Tube-shaped sponges

17. Leuconoid
Many canals from pore to smaller incurrent canals that branch repeatedly before arriving at the larger central cavity SPONGOCOEL
Most complex of plans, biggest sponges
greatly increases food collection surfaces

18. Food Chain Angel fish and hawkbilled sea turtles Rock Beauty Angel
Why don’t more animals eat sponges???

19. Symbiotic relationships
Fairy Crab hiding in the crevice of a barrel sponge
Brittle sea star on an Azure vase sponge

20. Human Use of Sponges
Sponge Industry Nearly brought Many sponges close to extinction
Demosponges – soft, flexible, strong