1. PHYLUM ARTHROPODA “JOINTED LEGS”

2. General Characteristics Largest phylum (75% all animals) Terrestrial, Freshwater, Saltwater

3. General Morphology Exoskeleton: outside; made of chitin (protein, sequence of amino acids) 1. Protection, attachment of muscles, support 2. Molt: Sheds exoskeleton as grows

4. 3. Body segmented; bilateral symmetry 4. Jointed appendages 5. Dioecious – males are separate from females Female Male

5. 6. Eyes – 2 types Compound – image forming (mainly insects) many eyes Simple – detect movement

6. TYPES (Classes) Insects - 750,000+ sp Rare in salt water; LOVE salt marshes (flies, mosquitoes)

7. Chelicerates – spiders, ticks, scorpions Horseshoe Crab- most primitive animal on Earth Soft bottom; shallow water; E. coast of N. America only 1 species

8. Crustaceans – crab, shrimp, lobster Mostly saltwater Gills to get oxygen Appendages specialized for crawling, swimming, mating, feeding

9. 2 pairs sensory antennae