1. 113-120(EDITION 14TH) 109-119 (EDITION 15TH)
Phylum Porifera
(EDITION 14TH)
(EDITION 15TH)

2. Goals for today
Learn to recognized the Phylum Porifera from other animals
Learn the main ‘diagnostic’ characteristics, structures, and their function
Learn about some sponges biology

3. Phylum Porifera Most are marine
Freshwater species are found in ponds and streams
Solitary or colonial
Adults are sessile and benthic

4. These are the simplest metazoans (multi cellular organisms)
Porifera = "pore bearer"
Porifera
Parazoa
Radiata
Deuterostomia
Ecdysozoa
Lophotrochozoa
Eumetazoa
Bilateria
Protostomia
Cnidaria and
Ctenophora
Ancestral colonial
choanoflagellate
These are the simplest metazoans (multi cellular organisms)
No organs, no mouth, no nervous, digestive or circulatory system, only rudimentary nervous integrations.
Little or no tissue organization
No germ layers (so neither diplo- or triploblastic)
Two thin layers of cells (Epidermis and Endodermis)
Some have radial symmetry some do not

5. Main characteristics of sponges are:
Phylum Porifera
Main characteristics of sponges are:
Internal skeletons of spicules or organic fibers (spongin).
Pores and canal systems (asconoid, siconoid, and leuconoid)
Internal cavity= spongocoel that opens to an osculum

6. Phylum Porifera Flagellated sponge feeding cells= choanocytes.
By cooperatively moving their flagella, choanocytes generate a flow of water through the sponges pores, into the spongocoel, and out through the osculum.

7. Phylum Porifera Feeding Behavior

8. Porifera: Classification
Classes:
Calcarea:
Spicules of calcium carbonate
Needle-shaped or 3-4 rayed spicules
Canal systems asconoid, siconoid, or leuconoid
All marine
Hexactinellida (Glass sponges):
3D, six-rayed spicules
Siliceous spicules (SiO2)forming a network
Body often cylindrical or funnel-shaped.
Canal systems siconoid or leuconoid
All marine, and most deep water spp.
Demospongiae:
Siliceous spicules (not six-rayed), spongin or both
Canal system leuconoid
One family freshwater, most marine
Most sponges belong to this class

9. Porifera: Your Tasks Exercise 7: Phylum: Porifera (sponges)
Class Calcarea
Genus: Sycon (=Scypha, Grantia)

10. Porifera: Sycon
2. Take a slide from your box with (Sycon, Grantia, or Scypha) this is a cross section cut: identify the incurrent canal, spongocoel, and the radial canal
Water enters the incurrent canals and passes through minute openings called? ____________
Check your book for answers!

11. Porifera: Sycon
What is the apopyle? Check your book!

12. Porifera: Sycon
3. Take a slide from your box with (Sycon, Grantia, or Scypha) in a longitudinal cross section you would see the following specialized cells: what are their function?

13. Porifera: Your Tasks Phylum: Porifera (sponges) Class Calcarea
Genus: Leucosolenia
Leucosolenia has an asconoide canal system

14. Porifera: Leucosolenia
Try to find the osculum. This is a colonial species of tubular individuals in various stages of development
osculum

15. Porifera: Leucosolenia
2. Look into the microscope a slide of Leucosolenia body and its spicules

16. Porifera: Your Tasks Phylum: Porifera
Class Hexactinellida (Glass sponges)
Genus: Euplectella

17. Porifera: Your Tasks 1. Look at preserved specimens of Euplectella
Some species of Euplectella have a commensal relationship with a shrimp species. A young male and female shrimp enter the central cavity and live there. As they grow they become too large to escape through the sieve-like covering of the osulum, and so spend their entire life inside the sponge.

18. Porifera: Your Tasks Phylum: Porifera (sponges) Class Demospongiae
Gemmulas (asexual reproductive structures)
-Gemmules are asexual reproductive structures of freshwater sponges and some marine sponges of the class Demospongiae.
-Made up of amoebocytes surrounded by a layer of spicules and can survive conditions that would kill adult sponges.
What is their function in reproduction?

19. Important Links Porifera