1. Reading Check
Sponges

2. Reading Questions, p
What is the name of the phylum for sponges?
What type of symmetry is displayed by sponges?
Name one body plan of the sponges.

3. Today’s Objectives
The student will list the characteristics, classification, economic importance, reproductive strategies and organizaiton of members of Phylum Porifera.

4. Characteristics of Poriferans
Assymmetrical or radially symmetrical
Nonmotile
No tissues or organs
Filter feeders
Three types of cells

5. Classification – Phylum Porifera
Based on type of spicules
Class Calcarea – CaCO3
Class Hexactinellida – SiO4
Class Demospongiae – spongin or SiO4 or both

6. Class Calcarea

7. Class Hexactinellida

8. Class Demospongiae

9. Cell types of sponges Pinacocytes Porocytes Mesohyl (amoeboid cells)
Choanocytes
Spicules of calcium carbonate or silica
Spongin skeleton

10. Body Types of Sponges
Ascon
Sycon
Leucon

11. Reproduction Monoecious Do not self-fertilize
Amoeboid cells or choanocytes undergo meiosis to form sperm or egg cells
Sexual reproduction – forms larvae
Asexual reproduction – forms gemmules

12. Economic Importance Commercial production of sponges
Artificial vs. Natural