1. Invertebrates Dr. M. Diamond
The Animal Kingdom
Invertebrates
Dr. M. Diamond

2. Porifera - Sponges Simplest animals Live in water (mostly marine)
No organs
No symmetry
Have pores and central cavity
Eat small floating organisms and debris
Collar cells – filter and digest food particles
Can regenerate

3. Cnidaria – Jellyfish and coral
Cnida (Gk.) - lasso
Jellyfish = medusae
Coral = polyps
Radial symmetry
Long tentacles
With nematocysts (stinging cells)
Complex tissues
Gut
Simple nervous system

4. Platyhelminthes - Flatworms
Planaria, flukes, tapeworms
Bilateral symmetry
Head
Eyespots – sense light
Sensory lobes on either side of head
Nervous system

5. Nematoda - Roundworms Bilateral symmetry Simple nervous system
Some are parasites

6. Mollusks – Snails, slugs, clams, squid, octopus
Most live in ocean
Some live on land or in fresh water
Bilateral symmetry
Foot
Gills, gut and other organs
Shell
Circulatory system (open)
More complex nervous system with brain

7. Annelids – Segmented worms
Bilateral symmetry
Earthworms, bristle worms and leeches
Nearly identical body segments
Closed circulatory system (like us)
Nervous system
Brain and nerve cord
True body cavity

8. Arthropods – Insects, spiders, crustaceans
Jointed limbs
Exoskeleton
Well-developed nervous system
Specialized parts (wings, claws, antennae, etc.)

9. Echinoderms – Sea stars, sea urchins, sand dollars, etc.
Internal skeleton
Nervous system with simple eyes
Water vascular system for movement
Adults – radial symmetry
Larva – bilateral symmetry