1. Introduction to PORIFERA
Biology 11
Mrs. Trevelyan

2. Porifera 1. PRESCRIBED LEARNING OUTCOMES and VOCABULARY 2. VIDEOS:
-None 
3. TEXTBOOK PGS
Section 26.1 pgs

4. Examples of Members:

5. Overview…

6. Three Classes of Porifera
1. Calcarea (bony sponges) use calcium-carbonate to make the skeleton, their internal hard structure. Usually very small, only 3-4 inches in height. About 400 species are in this group.
2. Hexactinella (glass sponges) use silicon dioxide to make their skeletons. Most live in great depths in the ocean. There are about 500 different kinds of glass sponges; they make for about 7% of all known sponges
3. Demospongiae contains most sponges (all large sponges). Make their skeleton from spongin, a special protein. Includes horny & bath sponges. Marine or freshwater

7. 1. Unifying Characteristics
Most primitive of all animals (eukaryotic heterozygote)
Predominantly marine except for two freshwater families
Multicellular, with loosely aggregated cells
Adults sessile (do not move), commonly encrusting.
No specialized tissue or organs, but there is some cell specialization
Asymmetrical or radially symmetrical

8. 2. Structure
Cellular differentiation, but no tissue layers (no organs!)

9. 2. Structure
Body permeated with pores, canals, and chambers through which water current flows
Internal cavities are, at least partially, lined with flagellated cells
Possess an internal skeleton of spicules and/or organic fibers.

10. 2. Structure
Inner cavity lined with COLLAR CELLS. These contain flagellum which create water current
Water moves into the sponge through INCURRENT PORES
Food particles are then digested by collar cells or AMEOBOCYTES. Ameobocytes make the crystal-like skeleton
Filtered water leaves the sponge through the OSCULUM (giant hole)

11. 3. Digestion No stomach or digestive system
Filter feeders (cells absorb microscopic plants and animals)
Video:
Simulation:

12. 4. Respiration/Excretion
Sponges have no respiratory or excretory glands/organs.
Use diffusion within individual cells.
As water passes through the body cell, sponge cells remove oxygen and give off carbon dioxide into the water.
The wastes that are produced by cellular respiration are also released into the water.
The water then carries the wastes away through the operculum

13. 5. Nervous System No nervous system (no nerves, no brain!)
Cells can still respond to stimuli

14. 6. Reproduction
Asexual by FRAGMENTATION (a piece falls off) or BUDDING (a small sponge grows on the parent)
Sexual by releasing sperm or sperm and eggs into the water. After fertilization the larvae swims to a surface and attaches itself.
Video: Spawning of Barrel Sponges

15. 6. Reproduction

16. 7. Additional Interesting Facts
Provide habitat for many marine animals
And form a symbiotic relationship with some
protists
Humans used sponges for baths/cleaning
Boring sponges release chemicals that break up shell and coral
Recent research shows some species may have antibiotic properties

17. Sponge Bob is No Sponge!!!