1. Arthropods! Do Now: 1.Turn in Earthworm dissection

2. Phylum Arthropoda Biggest phylum of animals currently alive and extinct. Several MILLION different species Exist in every environment, in almost every ecosystem on Earth. By any measure, the most “successful” animal phylum. ¾ of all known species of animal are arthropods.

3. What Makes an Arthropod? Exoskeleton: – Hard, protective outer “shell.” – Used for movement – Made with chitin, a polysaccharide.

4. Exoskeleton for Muscle Attachment Your muscles are attached to an endoskeleton. An exoskeleton serves the same purpose

5. What Else Makes an Arthropod? Bilateral symmetry

6. Segmented body plan Each segment has at least 1 pair of appendages. – Legs, antenae, flipers, claws, etc. are all appendages. – Some segments may be fused together.

7. 3 Main Body Sections Called tagmata: Some may be fused

9. Jointed Appendages (and lots of ‘em)

10. Recap: Arthropod Characteristics EXOSKELETON Bilateral symmetry Segmented body plan (3 main sections: head, thorax, abdomen) Jointed appendages (many pairs). Note: arthropod means “jointed foot.”

11. Arthropod Circulatory System Open circulatory system with heart.

12. Arthropod Respiration Gills/book lungs: oxygen diffuses into blood Trachea: air moves into insect directly

13. Types of Arthropods Domain: Eukyra Kingdom: Animalia Phylum: Arthropoda Classes: Crustacea, Insecta, Arachnida (+ Myriapoda

14. The Family Tree

15. Class Crustacea: The Crustaceans Only arthropod class with 2 pairs of antennae.

16. Includes crabs, lobsters, shrimp, as well as pillbugs. Class Crustacea: The Crustaceans

17. Crustacean Orders “True” Crustaceans = Order Decapoda – 5 pairs of thorasic legs – 2 tagmata Cephalothorax Abdomen “Pillbugs” = Order Isopoda – 7 pairs of thorasic legs – 3 tagmata

19. Class Insecta 1 pair of antennae 3 pairs of legs 3 tagmata Wings or wingless

20. Insect Diversity Biggest order of animal on Earth Over 900,000 documented species. Highest estimates suggest up to 30,000,000 species may exist.

21. Class Arachnida: Spiders, Ticks, Scorpions, Mites, etc. No antennae 4 pairs of legs

22. Arachnids Trilobites = Extinct Arachnids

23. Centipedes And Millipedes: Class Myriapoda One pair of antennae. Two tagmata: head and trunk 2 pairs of legs per segment Millipede subclass diplopoda 1 pair of legs per segment centipede subclass chilopoda

24. Recap: Arthropod Family Tree Phylum Arthropoda Class Crustacea Class Insecta Class Arachnida Class Myriapoda Deca- poda Iso- poda many ordersmany orders, including extinct trilobites Chilo poda diplo poda