Phylum Porifera

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 Porifera

Phylum Porifera

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

Hydra (Class Hydrozoa)

budding

Obelia (Class Hydrozoa)

Class Hydrozoa

Aurelia (Class Scyphozoa)

juvenile adult

Sea Jelly (Class Scyphozoa)

Sea Jellies (Class Scyphozoa)

Sea Jellies (Class

Scyphozoa)

Sea Jellies (Class Scyphozoa)

Videos:• Sea jelly in motion:

– http://www.youtube.com/watch?v=Bp8NlQUeTq8&feature=related

– http://www.youtube.com/watch?v=DPWGF-51QX4

Sea Anemone (Class Anthozoa)

Coral (Class Anthozoa)

Coral (Class Anthozoa)

Coral (Class Anthozoa)

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

Box jelly (Class

Cubozoa)

Box Jelly (Class Cubozoa)

Box Jelly (Class

Cubozoa)

Portugese Man of War (Class Hydrozoa)

Portugese Man of War (Class Hydrozoa)

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

Phylum Ctenophora

Phylum Ctenophora

Phylum Ctenophora

Phylum Ctenophor

a

Videos:• Comb jellies:

– http://www.youtube.com/watch?v=G7WT81ukHZE – http://www.youtube.com/watch?v=A9MppQlAykg – http://www.youtube.com/watch?v=icKB9EfURhQ