1. Sponges, Cnidarians,& Ctenophores

2. Phylum Porifera Characteristics
Includes marine & freshwater sponges
Found in the kingdom Animalia & subkingdom Parazoa
Sessile as adults
Simplest of all animals

4. Sponges characteristics continued
Contain specialized cells, but no tissue
Asymmetrical
Bodies filled with holes or pores for water circulation
Marine sponges are larger & more colorful than freshwater sponges
Range in size from 2 centimeters to 2 meters

5. What is the purpose of Bodies filled with holes or pores?
Group assessment
What is the purpose of Bodies filled with holes or pores?
How big can they get?

6. Sponges characteristics continued
Osculum is single, large body opening at the top for water & wastes to leave
Spongocoel is the body cavity of sponges
Have only 2 cell layers (ectoderm & endoderm) separated by jellylike material
Flagellated cells called choanocytes or collar cells line their internal body cavity
Flagella of choanocytes beat & pull in water containing food which the collar traps

8. Spicules are made of calcium carbonate or silica
Sponges continued
Spongin is a network of flexible, protein fibers making up the sponge's skeleton
Spicules are tiny, hard particles shaped like spikes or stars in the  skeleton of some sponges
Spicules are made of calcium carbonate or silica

10. What do Flagella of choanocytes do? What are spicules made of?
Group assessment
What do Flagella of choanocytes do?
What are spicules made of?

11. Feeding in Sponges
Sponges are filter feeders that remove plankton (food) from the water that is brought in through pores lined with collar cells
 Flagella pull in bacteria, protozoans, & algae that sticks to collar of choanocytes where it is digested
Amebocytes are specialized cells in sponges that can roam to pick up food from choanocytes & distribute it to all other parts of the sponge
Amebocytes also transport carbon dioxide & wastes away from sponge cells
Excess water & food leaves through the excurrent osculum

12. What do flagella do during feeding in a sponge?
Group assessment
What do flagella do during feeding in a sponge?
Where does the excess water and food go in a sponge?

13. Reproduction in sponges
Sponges can reproduce asexually by external buds that break off & form new sponges or stay attached to form sponge colonies
Gemmules are specialized, internal buds formed by sponges during cold or dry weather that can survive harsh conditions
Gemmules consist of a food-filled ball of amebocytes surrounded by a protective coat with spicules & released when adult sponge dies
Gemmules break open when conditions improve & the cells form new sponges

14. Reproduction in sponges
Sponge can also asexually regenerate missing parts or a new sponge from a small piece of sponge
Sponges are hermaphrodites (produce both eggs & sperm), but they exchange sperm & cross-fertilize eggs during sexual reproduction
Planula is the flagellated, free-swimming larva that forms from the zygote
Planula larva eventually settles to the bottom & attaches to develop into an adult, sessile sponge

15. How do sponges reproduce?
Group assessment
How do sponges reproduce?
What does it mean that sponges are hermaphrodites?

16. Classes of Sponges
Calcarea are chalky sponges with calcium carbonate spicules
Hexactinella includes glass sponges & the Venus flower basket with silica spicules
Demospongiae include horny & bath sponges with only spongin or spongin & silica spicules
Sclerospongiae are coral sponges & have spongin & silica and calcium carbonate spicules

17. Name two different classes of sponges.
Group assessment
Name two different classes of sponges.