1. ARTHROPODS

2. Arthropods  (“jointed foot”)  ¾ of all animals on planet Earth! 750,000+ species….why so numerous and successful?

3. 1: Reproduce fast & in large numbers  opportunity for variation is therefore great  take advantage of different food sources…pass through developmental stages such as ‘larva’ and ‘adult’ in metamorphosis

4. #2: Exoskeleton (outside) Changed the single fortress (shell) to a flexible suit of armor  Protection; barrier against loss of body fluids; must be recycled and shed (molted!) to make room for growth

5. #3: Segmentation  More flexible movement  Creates lots of interior ridges for muscle attachments, going in different directions

6. #4: Striated Muscles  voluntary and quick contracting (but, they get tired quickly….need lots of oxygen to burn food for quick energy!

7. #5: Efficient air moving systems  Gills in water; book lungs for spiders; tracheae (pipes) for insects

8. #6: jointed appendages  modified for locomotion (legs, wings), eating (claws, mouthparts), sensing (antennae)

9. #7: Sense Organs  eyes (simple or compound); hair on legs, body, antennae; chemical senses

11. Arthropod Groups (taxa) The arthropods are divided into two large groups that exist today: Chelicerates and Mandibulates

13. Chelicerate Arthropod Characters: Pincher-like mouthparts - chelicerae - and pedipalps NO antennae Two body regions, usually - cephalothorax & abdomen Four pairs of legs Horseshoe crabs and arachnids are only living groups

14. Orders of Arachnids Scorpions Pseudoscorpions Daddy Long-Legs Mites & Ticks Spiders

15. Scorpion Tick (a mite) Pseudoscorpion Daddy-long-legs Wolf Spider

16. Scorpion Anatomy

18. chelicerae eyespedipalp

19. Pseudoscorpion

20. pedipalps & chelicerae cephalothorax abdomen Mite and Tick Body Regions

21. American dog tick male Blacklegged (deer) tick female

22. American dog tick female laying egg mass (1000-2000 eggs!).

23. Clover mites Twospotted spider mites Predatory mite

24. daddy long-legs cephalothoraxabdomen

25. pedipalp chelicera (fang) cephalothorax abdomen narrow waist Spider Anatomy

26. Abdomen Pedipalp Chelicera (fang) Cephalothorax Jumping Spider

27. Wolf spider with egg caseSpitting spider Tarantula Orb-weaving spider

28. Black widow with egg case Brown recluse

29. Mandibulate Arthropod Characters: Mouthparts are mandibles - normally chewing sideways One or two pairs of antennae Various body region arrangements - cephalothorax & abdomen / head & trunk / head, thorax & abdomen Variable leg numbers Insects, crustaceans & myriapods

30. Classes of Myriapods (many legged arthropods) (all have one pair of antennae, a head region, and trunk with many pairs of legs, use trachea) Diplopoda - millipedes Chilopoda - centipedes

31. Myriapods Millipede (Diplopoda) Two pair of legs per visible segment, attached under body. Centipede (Chilopoda) Pair of fangs under head, one pair legs per visible segment - attached to side of body. No fangs, no eyes, legs attached to side of body. [one pair of antennae, head & trunk regions, trunk with many pairs of legs]

32. Millipede (Diplopoda) Centipede (Chilopoda) Garden centipede

33. Insecta Class  3 segments  head, thorax, abdomen  1 pair of antennae  Special characteristics:  Wings  Pheromones  Metamorphosis

34. Phereomones  Chemical signals  Used for  Marking trails  Identification of organisms  Signaling trouble  Signaling sexual readiness

35. Metamorphosis  Incomplete  Born as a smaller version of the adult  3 stages  Egg  nymph  adult  Nymph molts many times into different “stage” of nymph

37. Metamorphosis  Complete  Born as a complete different version than adult  88% of metamorphosis  4 stages  Egg  larva  pupa  adult

39. Classes of Crustacea mostly marine, fresh water, a few terrestrial all have two pair of antennae five or more pairs of legs segmented abdominal appendages head & trunk or cephalothorax & abdomen body arrangement have gills Sowbugs or pillbugs Sand fleas Barnacles Crabs, lobster, shrimp

40. Crayfish cephalothorax (Decapoda) Sowbug (Isopoda), a terrestrial crustacean