1. Arthropods
insects

2. Taxonomy Arthro- = joint Pod = foot
Examples: spiders, insects, shrimp, lobster, crabs, millipedes, centipedes

3. General Characteristics
The largest group of animals
Have a hard exoskeleton made out of chiton
Have jointed appendages for a wider range of motion
Air is piped directly to cells for higher metabolism
Demonstrate complex behavior patterns based on instinct

5. Body Plan
Body Plan: Jointed appendages, segmented body, bilateral symmetry and exoskeleton made of chiton for protection
Exoskeleton: hard outer covering that is sometimes molted
exoskeleton
molting horseshoe crab

7. Body Plan Segmentation: internally and externally segmented
Each segment contains spiracles and nerves
Head-thorax-abdomen or cephalothorax-abdomen
Jointed appendages: jointed legs allow for more advanced movement and modification for a wider range of habitats
Coelom: true body cavity filled with hemolymph (blood- like fluid)

8. Respiration
Respiration: (spiracles) a system of air tubes that deliver oxygen directly to cells

9. Digestion
Digestion: complete digestive system with specialized mouth parts and appendages (mandibles and palps) specialized for each food source

11. Circulation
Circulation: Open circulatory system with a heart, arteries and hemolymph
Hemocoel: the cavity that holds hemolymph fluid

12. Nervous System
Nervous System: brain, nerve cords, ganglia and specialized sensory organs

13. Movement
Movement: each arthropod has appendages that are specialized

14. Reproduction Reproduction: sexual reproduction: sexes are separate
Fertilization is internal and then eggs are laid

15. Metamorphosis
Metamorphosis: the changes in form that occur in an insects life cycle
Incomplete: larva-nymph-adult
Complete: larva-cocoon-adult
butterflies

18. Ecological Importance
Essential in food webs because they occupy every area on Earth
Essential in the pollination of many plants
Spread diseases (mosquitos, ticks)
Create products like honey, silk and beeswax
Are a food source for humans
insect dye

19. Class Merostomata Only five living species
Live in oceans but can swim up rivers
Can spend time out of water
Most ancient living arthropods
Examples: horseshoe crabs

20. Horseshoe Crabs

21. Horseshoe Crabs

22. Class Pycnogonida Number of legs varies from 8-12
Found in all oceans and all temperatures
Examples: Sea spiders

24. Class Branchiopoda 800 species Small: up to 10 cm long
Examples: brine shrimp, Water fleas, tadpole shrimp, clam shrimp

25. Water Fleas

26. Water Fleas

28. Tadpole Shrimp

29. Brine Shrimp

30. Class Malacostraca Live in water Pets and food for humans
Examples: Includes krill, sow bugs, lobsters, crayfish, shrimp, and crabs

34. Krill

35. Whale eating Krill

36. Krill

37. Krill

39. Lobsters

40. Shrimp

41. Crayfish

43. Crayfish

44. Crabs

51. red crabs Christmas island great migrations