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Filo Porifera. EJERCICIO 7 113-120(EDITION 14 TH ) 109-119 (EDITION 15 TH). 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 . - PowerPoint PPT Presentation
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Goals for today• Learn to recognized the Phylum Porifera from
other animals• Learn the main ‘diagnostic’ characteristics• Learn about some sponges biology
PoriferaThese 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
Porif
era
Parazoa
Radiata
Deut
eros
tom
ia
Ecdy
sozo
a
Loph
otro
choz
oa
Eumetazoa
Bilateria
Protostomia
Cnid
aria
and
Cten
opho
ra
Parazoa
Ancestral colonialchoanoflagellate
PoriferaMain 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
Calcarea: • Spicules of calcium carbonate• Needle-shaped or 3-4 rayed spicules• Canal systems asconoid, siconoid, or
leuconoid• All marine
Asconoide Siconoide Leuconoide
Classes:
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
Porifera: Your TasksExercise 7:
– Phylum: Porifera (sponges)– Class Calcarea
• Genus: Sycon (=Scypha, Grantia)
Sycon has a syconoid canal systemMarine
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: Sycon2. 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: Sycon2. 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: Sycon3. 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 TasksExercise 7:
– Phylum: Porifera (sponges)– Class Calcarea
• Genus: Leucosolenia
Leucosolenia has an asconoide canal system
Porifera: Leucosolenia1. Try to find the osculum. This is a colonial species
of tubular individuals in various stages of development
osculum
Porifera: Your TasksExercise 7:
– Phylum: Porifera (sponges)– Class Hexactinellida
• Genus: Euplectella
Porifera: Your Tasks
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.
1. Look at preserved specimens of Euplectella
Porifera: Your TasksExercise 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?