1. PHYLUM ARTHROPODA Arthropoda Characteristics:
All exhibit Bilateral Symmetry
All exhibit Segmentation
All possess an Exoskeleton
All possess Jointed Appendages  “Jointed Foot”

2. ARTHROPODA TAXONOMY There are 4 major SUBPHYLA within Arthropoda
Subphylum Trilobita – Now all extinct. Grand-daddy of all arthropods
Subphylum Uniramia – Unbranched appendages. Insects, centipedes
Subphylum Chelicerata – Possess Chelicera (usually fangs). Spiders, mites, ticks, scorpions.
Subphylums Crustacea – Possess two pair of antennae and harder exoskeleton. Crabs

3. SUBPHYLUM - CRUSTACEA Most Crustaceans are Aquatic.
-Over 35,000 species ranging in size from 0.25 mm  6 meters

4. -Unifying Characteristics :
1. Exoskeleton consists of the typical Chitin carbohydrate component, but made extra hard by being reinforced with Calcium Carbonate.
2. All Crustaceans will posses TWO pairs of antennae.
3. All Crustaceans will possess chomping jaw-like structures called MANDIBLES

5. DIVERSITY of Members

6. TYPICAL CRUSTACEAN – The CRAYFISH

7. JOINTED APPENDAGES

8. INTERNAL ANATOMY