1. Arthropods
Chapter 28

2. Characteristics of Arthropods
1. Arthropods share four main characteristics:
A. Segmented Bodies
Arthropods can have up to three sections
Head, Thorax and Abdomen

3. Three Body Sections

4. Characteristics of Arthropods
1. Arthropods share four main characteristics:
B. Exoskeleton (or outer shell)
Prevents evaporation
of water
ii. Used for protection

5. Characteristics of Arthropods
1. Arthropods share four main characteristics:
C. Jointed Appendages
Examples: Legs, wings and antennae
Give animal flexibility

6. 2. Shrimp, spiders and millipedes are all in the phylum
Arthropods
2. Shrimp, spiders and millipedes are all in the phylum
ARTHROPODA

7. Arthropods
3. Exoskeleton: Tough, external covering that is a suit of armor to protect the animal.
4. Purpose = Protection!

8. 5. Arthropod literally means…
“arthros” mean “jointed”
“podos” means “foot” or “leg”
Example: Wing, Legs and Antennae

9. Obtaining Food and Oxygen
6. Arthropods obtain food by:
Scavengers: Eats dead plant and animals
Herbivores: Eating plants
Predators: Eating animals they have killed

10. Circulatory System 7. Arthropods have an open circulatory system.
Blood leaves the blood vessels and moves through cavities.
Not the same as earthworms!

11. 8. Molting Molting: Shedding of the exoskeleton
Insects shed their outer skeleton to grow
Skin not flexible like ours

12. Classification
9. Arthropods are classified based on the number and structure of their body segments and appendages

13. Groups of Arthropods Group of arthropod Antennae Body Sections
Mouth Parts/
Appendages
Crustaceans
(Crustacea)
Two pairs
Two or three body section
Mandibles (chewing)
Spiders and Relatives (Chelicerates)
No antennae
Two body sections
Chelicerae (fanglike)
Four pairs of legs
Insects and Relatives
(Uniramia)
One pair
Unbranched appendages
(Insects have three sections)
Jaws

14. Spiders and Relatives (Chelicerates
What is it?
Organism
Group
How do you Know?
Spiders and Relatives (Chelicerates
Two Body section
Crustaceans
(Crustacea)
Two pair antennae
Insects and Relatives
(Uniramia)
Three body sections

15. Crustaceans 11. Function of parts of crustaceans
Cephalothorax: Fusion of the head with the thorax; houses most internal organs
Carapace: Exoskeleton that covers the cephalothorax
Manible: Mouthpart adapted for biting and grinding food
Chelipeds: Large claws that are modified to catch, pick up, crush and cut food
Swimmerets: Flipper-like appendages for swimming

16. Spiders and Their Relatives
12. Some Chelicerata include…
Horseshoe crabs, spiders, mites, ticks and scorpians

17. 13. Chelicerae vs Pedipalps
Both are appendages that are attached near the mouth and adapted as mouth parts
Chelicerae contain fangs and used to stab and paralyze prey
Pedipalps are longer and usually modified to grab prey

19. Insects and Their Relatives
14. Centipedes, millipedes and insects belong to the subphylum Uniramia.

20. Centipedes & Millipedes
15. What’s the difference?
“millipede” means “thousand feet”
“centipede” means “hundred feet” NO
SIGNIFIGANCE!

22. Insects Head Thorax Abdomen 16. Three parts of an insect:
Appendages found on same section on all insects

23. Insects 17. Adaptations to respond to stimuli
Compound eye to detect changes in color and motion
Chemical receptors for taste and smell on mouthparts
Chemical receptors also on their antennae and legs

24. Adaptations for Feeding
18. Insects have various mouth parts in order to get food in a way that best fits them

25. Metamorphosis
Complete
Gradual