Phylum Porifera

1
Phylum Porifera

• Ex. Sponges
• Multicellular WITHOUT TISSUES
• Hermaphroditic
• Heterotrophic filter feeders
• Asymmetrical
• No cephalization present
• No coelom
• Basic body parts ostia, spongocoel, osculum,
  choanocytes with flagella

Actor
Real Sponge Bob
2
Phylum Cnidaria

• Ex. Jellyfish
• Two germ layers ectoderm and endoderm
• No cephalization
• No coelom
• Soft, sac-like body plan, two way digestion (with
  one opening mouth)
• Two body forms sessile polyp and free-swimming
  medusa
• Basic body parts bell, cnidocytes (stinging
  cells) with nematocysts, tentacles,
  gastrovascular cavity, gonads

Jellyfish
Phylum Cnidaria
Phylum Porifera
3
Phylum Platyhelminthes

• Ex tapeworms
• Three germ layers ectoderm, mesoderm, endoderm
• Bilateral symmetry
• Cephalization is present
• No coelom acoelomates!!!!
• Use diffusion to transport materials through body
• Mouth forms first protostomes
• Basic body parts mouth, pharynx, intestine,
  ganglia primitive brain, flame cells - rid of
  waste
• Cut one in half (lengthwise) it will grow
  back!!!!

4
Figure 33.12 Anatomy of a tapeworm
5
Phylum Nematoda

• Ex. Pinworms
• Three germ layers present ectoderm, mesoderm,
  endoderm
• unsegmented
• Bilateral symmetry
• Cephalization present
• Pseudocoelom present
• Mouth forms first protostome
• Basic body parts mouth, anus, intestines

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Figure 33.25ax Nematode, C. elegans
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Phylum Mollusca

• Ex. Clam, squid
• Three germ layers present ectoderm, mesoderm,
  endoderm
• Have an external or internal shell for support
• Bilateral symmetry
• Cephalization present
• Has a TRUE COELOM
• Mouth develops first protostome
• Basic body parts gills, specialized foot

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Phylum Annelida

• Ex earthworm
• Three germ layers present
• Bilateral symmetry present
• Cephalization present
• True coelom present
• Mouth develops first protostome
• Basic body parts mouth, anus, specialized
  intestine, segments

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Figure 33.23 Anatomy of an earthworm
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Phylum Arthropoda

• Ex. Insects, spiders, crayfish, millipedes,
  centipedes
• Three germ layers present
• Exoskeleton present that requires molting
  (shedding)
• Jointed appendages
• Bilateral symmetry
• Cephalization present
• True coelom present
• Mouth forms first
• Basic body parts head, thorax, abdomen, (or
  cephalothorax and abdomen), spiracles and
  tracheae, open circulatory system

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Phylum Echinodermata

• Ex starfish
• 3 germ layers present
• Biradial symmetry in adults
• No cephalization in adults
• True coelom present
• Anus forms first deuterostome!!!
• Basic body parts spiny skin, endoskeleton,
  water vascular system, tube feet