1. Phylum Porifera: Sponges
Chapter 6

2. Types of Cells Pinacocytes (Epidermal Cell)
Porocytes (Water Flow Through Cell)
Choanocytes (Collar Cells)
Archeocytes (Amoebocytes)

3. I. Pinacocytes Cells of the external epithelium Main functions:
Structure
Contraction

4. II. Porocytes
Cells which form pores
Function: to allow water flow

5. III. Chanocytes Line the flagellated canals and chambers.
Main function: to create water flow.

6. Codosiga

8. Sponge feeding

13. Diameter of channels influences water flow velocity.
Particles that are captured are in the 2-5 µm range.

14. Cladorhizid carnivorous sponge
Predatory sponges
Cladorhizid carnivorous sponge

15. The Harp Sponge, Chondrocladia lyra

16. IV. Archaeocytes Ameboid cells which can be non-sessile
Found in cellular matrix
Main function:
Digestion
Secrete structural components
Spongin
Spicules

17. Sponge feeding

18. Sclerocyte in the process of secreting a spicule

19. Keeping the mesohyle together
Spongin
Spines (spicules)
Siliceous
Calcareous

20. Spongin
Fibers of collagen

21. Spicules
Spines, when placed together form a very rigid skeleton

22. Megascleres And Microscleres

23. Main Groups of Sponges P: Porifera C: Calcarea C: Hexactinellida
C: Desmospongiae

24. Calcarea Calcareous sponges Spicules composed of calcium carbonate
Small < 10 cm tall

25. Calcareous sponges

26. Hexactinellida Glass sponges Some spicules fused to form skeleton
Spicules made of glass (Siliceous spicules) six rayed
Deep water sponges

27. Siliceous spicules in Hexactinellida (Triaxon) six rayed spicules.

29. Desmospongiae Common sponges Skeleton is variable Can be large
Spicules
Spongin
both
Can be large

30. Siliceous Spiculse in Desmospongia
Never six-rayed
Microscleres
Megascleres

31. Sclerospongiae
Sclerosponges were first proposed as a class of sponges, in 1970 by Hartman and Goreau.
Sclerosponges are sponges with a soft body that covers a hard, often massive limestone basal skeleton.
Because of their long life span (500-1,000 years) it is thought that analysis of these sponges could extend data regarding ocean temperatures, salinity, and other variables farther into the past than has been previously possible.
However, it was later found that the sclerosponges are not a monophyletic group (they are polyphyletic) and therefore this class is currently not recognized.

32. The Big Picture Sponges are metazoans, but don’t have true tissues
They are an ancient group
Three main groups (taxonomic), which fall into three main structural groups
Four types of specialized cells *choanocyte*