1. 1 Phylum Arthropoda Arthro = jointed poda = footArthro = jointed poda = foot

2. 2 Arthropoda Characteristics Largest phylum –900,000 species –75% of all species Most successful –Ecologically diverse –Present in all regions of the earth Bilateral Symmetry, Triploblastic Schizocoelous –Coelum formed from mesoderm.

3. 3 Arthropod Groups 1.Subphylum Trilobita - extinct trilobites 2. Subphylum Chelicerata –horseshoe crabs, Class Arachnida –spiders, ticks, mites, and some extinct groups 3. Subphylum Myriapoda –centipedes, millipedes 4. Subphylum Crustacea –crabs, lobsters, shrimps, barnacles 5. Subphylum Hexapoda Class Insecta

4. 4 Subphylum Trilobita Extinct tri= three; lobos= lobes Divided into 3 longitudinal regions or lobes.

5. 5 Subphylum Chelicerata Horseshoe crabs, & Arachnids (spiders, ticks, mites, scorpions) –No antennae –Most suck liquid food from prey

6. 6 Class Arachnida Spiders, ticks, scorpions –Most are predaceous –Most are harmless/beneficial to humans –Some ticks and mites spread disease & cause irritation Scorpion Dust mite

7. 7 MYTH: Daddy longlegs (Harvestmen) are one of the most poisonous spiders but their fangs are too short to bite humans: MYTH (!!!!!!!) Daddy longlegs: Order Opilionid Spiders: Order Araneae One basic body segment (no pedicel) Don ’ t produce silk No venom, fangs\ daddy longlegs Urban legends

8. Subphylum Myriapoda 8 Centipede & milipede

9. 9 Subphylum Crustacea shrimp lobsters amphipods euphausids (krill) crusta= shell Phylum Arthropoda Lobster, crayfish, shrimp, crab, water flea, barnacles, krill Aquatic (mostly marine) –a few terrestrial forms Major ecological and economical importance.

10. 10 Barnacles “ nothing more than a little shrimplike animal standing on its head in a limestone house and kicking food into its mouth ” -Louis Agassiz

11. Subphylum Hexapoda Class Insecta 11