1. Phylum PoriferaThe Sponges

2. Classes of Porifera • Class Calcarea (e.g., Leucosolenia) • Class Hexactinellida (e.g., Euplectella) • Class Demospongiae (e.g., Spngilla)

3. General Characteristics • Most are marine; a few live in fresh water one family Spongillidae • Metazoan, with loosely aggregated cells, therefore no organs or true tissues. • Asymmetrical or radial symmetry • Body with pores (ostia and osculum), canals, and chambers through which a water current flows.

4. General Characteristics • Epidermis of flat pinacocytes; • Inner surfaces lined with flagellated collar cells (choanocytes)-create water currents • matrix called mesohyl contains amebocytes • and skeletal elements • Skeleton of calcareous or siliceous crystalline spicules and/or protein fibers (spongin)

5. General Characteristics • Digestion intracellular • Respiration and excretion by diffusion • Nervous system absent • All adults sessile and attached to substrate • Asexual reproduction by buds or gemmules • Sexual reproduction by eggs and sperm • Free-swimming ciliated amphiblastula larvae

8. Figure 12.11

11. Figure 12.12a

13. Class Calcarea • also known as Calcispongiae • have spicules of calcium carbonate • all marine Leucosolenia

14. Leucosolenia

15. Grantia (Scypha)

16. Schypha (Spicules)

17. Class – HexactinellidaThe Glass Sponges • Glass sponges; • have siliceous spicules, • body often cylindrical or funnel shaped

18. Class - Hexactinellida

19. Class - Demospongiae • have siliceous spicules, spongin, or both • one freshwater family • Spongillidae • Has gemmules during the winter

20. Gemmule

21. Gemmule

22. Figure 12.co

23. Figure 12.08

24. Figure 12.17

25. Figure 12.17a

26. Figure 12.17b

27. Cliona

28. Cliona

29. Cliona killing a coral