1. EJERCICIO 7 113-120(EDITION 14TH) 109-119 (EDITION 15TH)
Filo Porifera
EJERCICIO 7
(EDITION 14TH)
(EDITION 15TH)

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

3. These are the simplest metazoans
Porifera
These are the simplest metazoans
Little or no tissue organization
Said to belong to the cellular level of organization.
No organs, no systems, no mouth, or digestive tract, only rudimentary nervous integrations.
No germ layers (so neither diplo or triploblastic)
Asimetric
Porifera
Parazoa
Radiata
Deuterostomia
Ecdysozoa
Lophotrochozoa
Eumetazoa
Bilateria
Protostomia
Cnidaria and
Ctenophora
Ancestral colonial
choanoflagellate

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

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

6. Porifera: Classification
Classes:
Asconoide
Siconoide
Leuconoide
Calcarea:
Spicules of calcium carbonate
Needle-shaped or 3-4 rayed spicules
Canal systems asconoid, siconoid, or leuconoid
All marine
Hexactinellida:
3D, six-rayed spicules
Siliceous spicules 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 systems leuconoid
One family freshwater, most marine
Most sponges belong to this class

7. Porifera: Your Tasks Exercise 7: Phylum: Porifera (sponges)
Class Calcarea
Genus: Sycon (=Scypha, Grantia)
Sycon has a syconoid canal system
Marine

8. Porifera: Sycon
Put a preserved Sycon in a petri dish for you to take a look at the shape, osculum, and spicules. There is also a model of Sycon, learn about its parts

9. 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!

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
What is the apopyle? Check your book!

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

12. Porifera: Your Tasks Exercise 7: Phylum: Porifera (sponges)
Class Calcarea
Genus: Leucosolenia
Leucosolenia has an asconoide canal system

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

14. Porifera: Leucosolenia
2. Look in the micro a slide of Leucosolenia body and its spicules

15. Porifera: Your Tasks Exercise 7: Phylum: Porifera (sponges)
Class Hexactinellida
Genus: Euplectella

16. 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.

17. Porifera: Your Tasks Exercise 7: Phylum: Porifera (sponges)
Class Demonspongiae
Gemmulas (asexual reproductive structures)
Gemmules are asexual reproductive structures of freshwater sponges and some marine sponges of the class Demonspogiae
What is their function in reproduction?

18. Important Links Porifera