Filo Porifera
EJERCICIO 7
113-120(EDITION 14TH)
109-119 (EDITION 15TH)
Goals for today
• Learn to recognized the Phylum Porifera from
other animals
• Learn the main ‘diagnostic’ characteristics
• Learn about some sponges biology
Porifera
These are the simplest
metazoans
Protostomia
Bilateria
Radiata
Parazoa
Eumetazoa
Ancestral colonial
choanoflagellate
Deuterostomia
Ecdysozoa
Lophotrochozoa
Cnidaria and
Ctenophora
Porifera
Parazoa
• 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
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
Porifera
• Most are marine
• Freshwater species are found
in ponds and streams
• Solitary or colonial
• Adults are sessile
Porifera: Classification
Classes:
Calcarea:
• Spicules of calcium carbonate
• Needle-shaped or 3-4 rayed spicules
• Canal systems asconoid, siconoid, or
leuconoid
• All marine
Asconoide
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.
Siconoide
Leuconoide
Demospongiae:
• Siliceous spicules (not six-rayed),
spongin or both
• Canal systems leuconoid
• One family freshwater, most marine
• Most sponges belong to this class
Porifera: Your Tasks
Exercise 7:
– Phylum: Porifera (sponges)
– Class Calcarea
• Genus: Sycon (=Scypha, Grantia)
Sycon has a syconoid canal system
Marine
Porifera: Sycon
1. 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
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!
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!
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?
Porifera: Your Tasks
Exercise 7:
– Phylum: Porifera (sponges)
– Class Calcarea
• Genus: Leucosolenia
Leucosolenia has an asconoide canal system
Porifera: Leucosolenia
1. Try to find the osculum. This is a colonial species
of tubular individuals in various stages of
development
osculum
Porifera: Leucosolenia
2. Look in the micro a slide of Leucosolenia body and
its spicules
Porifera: Your Tasks
Exercise 7:
– Phylum: Porifera (sponges)
– Class Hexactinellida
• Genus: Euplectella
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.
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?
Important Links
Porifera
http://bioweb.uwlax.edu/zoolab/Table-Of-Contents.htm
http://faculty.uml.edu/rhochberg/hochberglab/Courses/InvertZool/Quize
s/Porifera%20Quiz%201.html
http://www.bumblebee.org/invertebrates/Porifera.htm