1. Meet the Lower Invertebrates
Kingdom-Animalia

2. Major Invertebrate Phyla
1) Phylum Porifera
2) Phylum Ctenophora
3) Phylum Cnidaria
4) Phylum Platyhelminthes
5) Phylum Annelida
6) Phylum Mollusca
7) Phylum Echinodermata
8) Phylum Arthropoda

3. Symmetry

4. 1) Phylum Porifera
-Example: Sponges
-Named for many
pores
-No symmetry
(asymmetrical)
-Most primitive
(simple) animals –
no organs

5. 2) Phylum Ctenophora
-Example: Comb jellies
-Radial symmetry
-Harmless bioluminescent
jellies

6. 3) Phylum Cnidaria
-Jellyfish (AKA Sea Jellies), sea
anemones, and corals
-Members of this group have
stinging cells
-Radially symmetrical
-2 tissue layers
-No organs

7. 4) Phylum Platyhelminthes
-The
Flatworms
-Bilateral
symmetry
-Simple

8. 5) Phylum Annelida
-The Segmented Worms
-Examples-Polychaetes
(and Earthworms on
land)
-Bilateral Symmetry
-Advanced worms

9. 6) Phylum Mollusca
-Examples: Clams, snails, octopus, squid
-Soft bodied animals with a large “foot”
-Bilateral symmetry

10. 7) Phylum Arthropoda
-Examples: Crabs,
lobsters, barnacles,
insects, arachnids
-Exoskeleton
-Jointed or hinged
appendages
-Bilateral symmetry

11. 8) Phylum Echinodermata

12. 8) Phylum Echinodermata
-Examples: Sea
stars, sea urchins,
sand dollars, sea
cucumbers
-Bumpy skinned
animals
-Pentamerous radial
symmetry