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Phylum Porifera• Means “pore-bearer”• Asymmetry…no definite shape• Sessile as adults• Includes sponges…not very complex
(no tissues/organs/systems)• Life functions take place at cell level.• Outer layer of cells, inner layer of cells
“jelly” in between (mesohyl)
• Some have spicules (CaCO3) for support/structure.
Phylum Porifera• Water goes in through holes in
side (ostia) and out through the top hole (osculum)
• Cells called choanocytes (collarcells) have flagella that move the water and filter out bits of organic material (filter feed)
• Amoebocytes move the food around the mesohyl
Phylum Porifera• Reproduce by:
– regeneration (broken parts grow new ones)
– budding (new one grows off of old one, eventually separates)
– gemmule (when conditions bad, makes a ball of
amoebocytes)– sexually by egg and sperm
(hermaphroditic) swimming larva
Phylum Cnidaria• Radial symmetry• A few tissues and organs• Includes hydra, jellyfish, coral,
sea anemones, Portuguese man of war
• 2 shapes during lifetime;– Medusa (bell shape, motile)– Polyp (tube shape, sessile)
Phylum Cnidaria• Outer and inner layer of cells
– epidermis … “outside skin”– gastrodermis … “stomach skin”
• Central gastrovascular cavity surrounded by tentacles with stinging cells (cnidocytes)
• Nerve net for body control…not a brain, but some cells that work together for motion
Phylum Cnidaria• Classes:
– Hydrozoa (polyp is adult form)•Portugese Man of War, Hydra, Obelia,
– Cubozoa (box jellies)– Scyphozoa (“cup animals” medusa
is adult form)•Sea jellies
– Anthozoa (“flower animals”)•Sea anemone, coral
Videos:• Sea jelly in motion:
– http://www.youtube.com/watch?v=Bp8NlQUeTq8&feature=related
– http://www.youtube.com/watch?v=DPWGF-51QX4
Videos:• Sea anemone feeding:
– http://www.youtube.com/watch?v=o1A5acWEERA&feature=related
• Coral eating:– http://www.youtube.com/watch?
v=Rqhp_RtP44Q&feature=related
Phylum Ctenophora• Comb jellies• Similar to sea jellies, except:
– No cnidocysts on tentacles… sticky cell instead of stinging
ones (colloblasts)– Move via cilia in rows on outside
(not pulsing)– Bioluminescence: an algae
symbiotically lives inside