1. By Albert Chen and Anne Ning
Porifera
a.k.a. “Pore bearers,” or sponges
By Albert Chen and Anne Ning
Campbell, Neil A., and Jane B. Reece. Biology. 7th ed. San Francisco: Pearson, Benjamin Cummings, 2005.
(textbook used on all slides)

2. Sponges Albert Chen Anne Ning

3. Body Cavity One central cavity called a spongocoel
Water enters the spongocoel through porocytes
Albert Chen
Anne Ning

4. Body Symmetry Nervous System Gas Exchange None None
Individual cells respond
to the environment
Gas Exchange
Individual cells obtain the oxygen they need from their surroundings
Albert Chen
Anne Ning
(left)
(right)

5. Circulatory System
Water is circulated by the movement of choanocyte flagella
Nutrients from the water are circulated by amoebocytes
Albert Chen
Anne Ning

6. Digestive System Suspension feeders
Choanocytes move water, catch suspended food with their collars, and ingest it through phagocytosis.
Food is then transferred to amoebocytes (with pseudopodia) that digest it and transport its nutrients to other cells.
Albert Chen
Anne Ning

7. Excretory System
Possess large openings called oscula from which water (and waste) leave
Albert Chen
Anne Ning

8. Locomotion/Musculature
No muscles
Flagellated choanocytes create water currents that bring water in to the spongocoel
Osculum can be closed
Sponges do not move
They are so stationary that the ancient Greeks mistook them for plants
Albert Chen
Anne Ning

9. Skeletal Type Amoebocytes produce skeletal fibers within the mesohyl
Spicules (sharp) are made from calcium carbonate or silica
Fibers produced from spongin are more flexible
Albert Chen
Anne Ning
Invertebrate biology [ ] Calcinai year: 2006 vol: 125 issue: 3 pg:

10. Reproduction
Sponges are hermaphrodites— produce both sperm and eggs (one gender at a time)
Gametes are produced by choanocytes or amoebocytes
Eggs stay in mesohyl while sperm leave through osculum. (no self-fertilization)
Larvae swim (or crawl) somewhere, stick, and develop into sessile adults.
They can also reproduce asexually by releasing fragments of adult sponge (gemmules) that can become individual sponges
Albert Chen
Anne Ning
"The Sponges (Phylum Porifera)." The Earth Life Web. Web. 10 Mar
<

11. Additional Information
Sponges are involved in symbiosis with algae. In some examples, the “alga represents the main skeleton of the sponge.”
Size—wide range from 1cm to 2m.
9000 species in this phylum, most live in the ocean.
Sponges can produce antibiotics to defend against pathogens
Few predators because of toxins
Albert Chen
Anne Ning
Invertebrate biology [ ] Calcinai year: 2006 vol: 125 issue: 3 page:

12. Taxonomy One taxonomic scheme: Phylum Porifera Class Calcarea
Order Calcinia
Order Calcaronia
Class Hexactinellida
Order Amphidiscophora
Order Hexasterophora
Class Demospongiae
Order Homoscleromorpha
Order Tetractinomorpha
Order Ceractinomorpha
Albert Chen
Anne Ning
"The Sponges (Phylum Porifera)." The Earth Life Web. Web. 10 Mar
<

13. QUIZ – Question 1 Which of the animal phyla has no true tissues?
Porifera
Cnidaria
Rotifera
Annelida
Albert Chen
Anne Ning

14. ANSWER: a) Porifera
Albert Chen
Anne Ning

15. QUIZ – Question 2 Which invertebrate has no true symmetry? Porifera
Mollusca
Echinodermata
Rotifera
Albert Chen
Anne Ning

16. ANSWER: a) Porifera
Albert Chen
Anne Ning

17. QUIZ – Question 3 Are Porifera protostomes or deuterostomes?
Both
Neither
Albert Chen
Anne Ning

18. ANSWER: d) Neither
Albert Chen
Anne Ning

19. QUIZ – Question 4 Which cells in sponges help to circulate water?
Osculum
Spicules
Amoebocytes
Choanocytes
Albert Chen
Anne Ning

20. ANSWER: d) Choanocytes
Albert Chen
Anne Ning