1. Arthropods By Devin Holmes

2. Arachnida SPIDERS 2 body regions 6 pairs of jointed appendages First 2 pairs used for feeding Other appendages are modified as legs for locomotion Have no antennae All spin silk; all do not make webs

3. Arachnida TICKS One body section Feed on blood Can expand to 1cm Can carry disease

4. Arachnida MITES One body section Usually no visible to the naked SCOPIONS Enlarged pinchers, tail with venomous stinger Live in warm, dry climate Eats insects and spiders Paralyze large prey with poison

5. Crustacea Most are aquatic and have feathery gills Only arthropods that have two pairs of appendages Have mandibles for crushing food Two compound eyes Many have five pairs of walking legs Have two or three body parts Examples: crabs, lobster, water fleas, shrimp, crayfish, barnacles

6. Chilopda Centipedes Carnivorous-eat soil arthropods, snails, slugs, and worms Bite is harmful to humans Have tracheal tubes for gas exchange 15 to 181 body parts (always an odd number)

7. Diplopoda Millipedes Eats mostly plants and dead material Do not bite Can spray obnoxious-smelling fluid 100 segments-each with 2 spiracles and 2 pairs of legs

8. Merostomata Horseshoe crabs Considered living fossils Unchanged from over 500 million years ago Protected by exoskeleton Migrate to shallow water during mating season Female lays eggs on land

9. Insecta Insects Most successful arthropods Largest group More species of insects than all other of classes of animals combined Mate once or just a few times Internal fertilization examples: flies, grasshoppers, butterflies, bees, and beetles