Invertebrates

1. Invertebrates Phylum Porifera

2. There are 2 Types of animals • Vertebrates: Animals with backbones. • Invertebrates: Animals without backbones. * About 97% of all animal species are inverts.

3. Kingdom Animalia Phylum Porifera • Phylum Porifera (“pore bearers”) • About 5,000 to 10,000 species • Are the simplest multicellular animals • Cells are independent of each other • Rely on water current for food, gas exchange, excretion, & reproduction

4. Turn Volume up An Introduction

5. Porifera • Most are marine (saltwater) • Have tiny pores on the surface to allow water to enter & circulate through a series of canals where planktonic organisms are filtered out and eaten

6. Porifera Planktonic: Describes small organisms that passively float or drift in a body of water.

7. Porifera • All are sessile: Living attached to the bottom or a surface. • All are filter feeders: Actively filter suspended food from the water

8. Porifera: Anatomy • The outer surface is covered with flat cells and sometimes tube-like pore cells called ostia, which form canals to allow water to enter. • Simple sponges have one large atrium in the center which is also called a spongocoel

9. Fish in Atrium/Spongocoel

10. Porifera: Anatomy • Water is pumped into a larger canal lined with collar cellsalso calledChoanocytes, which have a flagellum that creates currents and a collar that traps food. Food gets trapped here

11. Porifera: Eating • After choanocytes trap food on their collar, and is moved along to the base of the collar • Food is then engulfed by the cell to form a food vacuole, and is digested by enzymes and pH changes • Digested food is passed to amoeboid cells, & distributes it to other cells

12. Porifera: Anatomy • Water leaves through the osculum, a large opening on the top

13. Sponges are Filter Feeders

14. Spongin Spongin: Resistant fibers for support. Magnified spongin Highly magnified spongin

15. Porifera: Anatomy • Larger sponges need spicules for support * Are different shapes & sizes

16. Porifera: Body Forms 1. Ascon: Simplest & least common body form • Considered “simple sponges” • Porocytes regulate water circulation by contracting • Ostia are the outer openings of porocytes & lead directly to a chamber called the spongocoel. • Choanocytes use their flagellum to move water into the spongocoel, which then exits out the osculum.

17. Ascon Body Form

18. Porifera: Body Forms 2. Sycon is when the sponge wall appears folded • Water enters through openings called dermal pores • Pores contract incurrent canals, and the radial canals leads to the spongocoel • Choanocytes (collar cells) line the radial canals • Water travels from the ostia, through incurrent & radial canals, to the spongocoel, and out the osculum

19. Sycon Body Form

20. Porifera: Body Plan 3. Leucon: Have extensive branched canal system • Considered “Complex Sponges” • Water enters the sponge through ostia and moves through branched incurrent canals, which lead to choanocyte-lined chambers • Canals leading away from the chambers are called excurrent canals • Do NOT have a spongocoel (Atrium) • Have multiple exit points (oscula) for water leaving the sponge • Have increased surface area and filter large volumes of water

21. Leucon Body Form

22. Sponge Reproduction • Many are asexual: branches or buds break off and grow into separate sponges identical to the original one. * No Sound *

23. Sponge Reproduction • Sexually: When both sexes release gametes during the spawning season. Gametes: Haploid cells (sperm or egg) that functions in sexual reproduction. The union of 2 gametes of opposite sex produces a zygote. *** What are gametes? ***

24. Sponge Reproduction Spawningis the production or depositing of large quantities of eggs and sperm in water. Frog Spawn Fish Spawning Clam Spawning

25. More Sponge Spawning Pics.

26. Sponge Reproduction • Zygote: Diploid Cell produced by the fusion of an egg and sperm. A fertilized egg cell. sperm Haploid Cell Zygote Diploid Cell

27. Sponge Reproduction • Most sponges can produce both male and female gametes in the same individual and is called monoecious • Some are dioecious meaning that they have separate sexes in each individual (either male OR female…not both) We are DIOECIOUS! Are we monoecious or dioecious?

28. Sponge Reproduction • Once the egg is fertilized, a larva is formed • Larva: Is an immature stage that may undergo a dramatic change in structure before changing to the adult body form • After no more than 2 days of free-swimming existence, the larva settles to the substrate and begins to develop into the adult form What is “Substrate”?

29. Types of Sponges • Encrusting: form thin brightly colored growths on rocks or dead coral.

30. Types of Sponges • Glass sponges: live in deep water & have skeletons of fused silica spiclues. (example: Venus Flower Basket)

31. Types of Sponges • Boring Sponges: bore thin channels through oyster shells and corals.

32. Types of Sponges • Coralline Sponges: A calcium carbonate skeleton forms under the body. Once thought to be extinct, but have since been found in caves and on steep coral reef slopes.

33. Commercial Importance • Bath Sponges: Harvested & used to bathe with • Medical: Some act as antibiotics & others have painkilling properties (still researching)

34. Turn Volume down Harvesting Sponges

35. The End.