1. Chapter 31
Arthropods

2. 31-1 Features
Phylum Arthropoda

3. Includes insects, spiders, crayfish,…
Most successful animal group

6. Arthropods are the most diverse Group of animals.
They live in the land, sea, and air!
There are approximately
900,000 species of arthropods!

7. They vary in size from about
8 micrometers to about
12 feet across!

8. Arthropods have 8 similar Characteristics…
Jointed Appendages
Segmentation
Distinct Head with Compound Eyes
Exoskeleton
Tracheae
Open Circulatory System
Malpighian Tubes
Wings

9. Appendages are structures that Extend from the arthropod’s Body wall.
They are basically jointed foot.

12. Antennae-

13. Segmentation

15. Two sets of eyes:
Ocelli
Compound

17. Skeletal
Exoskeleton
Made of Chitin

19. Growth and Development

20. As arthropods grow they have to Create a new exoskeleton,
This is molting.

22. Cicada Molting
Adult breaks through ecdysial [ek-diz-ee-al] suture in the insect exoskeleton

23. Respiratory System Varies: Crabs and shrimp = gills
Horseshoe crab = book gills

24. Insects use trachea - a network of fine tubes
Spiracles - tiny holes where air enters
Pg 686

25. Digestive System Tube-in-a-tube Malpighian Tubules All eating habits
Absorb nutrients and pass
Them through anus
All eating habits
Locust = herbivores
Scorpion = carnivore
Ticks and fleas = parasites

26. Mouth adapted to food source

27. 31-2 Spiders & Arachnids

28. Spiders have mouthparts called Chelicerae, or fangs.
The second set of appendages are
Pedipalps which are used to
Catch and handle prey.

29. Only 2 species of spiders in the US Are poisonous to humans,
The Black Widow
And
The Brown Recluse
Both are here in Ohio.

30. They build webs from spinnerets Located at the end of the Abdomen.
Spiders wrap prey in their silk
And suck out their insides.

31. Scorpions and mites are arachnids.
Fleas and ticks are mites.
Mites are the major cause of
Indoor allergies in humans.

32. Subphylum Uniramia 31-3 Insects
Centipedes, millipedes, and all insects
One pair antennae; two pair wings
Appendages do not branch

33. Most insects have chewing Mouthparts called mandibles.
Most scientists agree that there
Are more than 700,000 species.

34. The insect life cycle is complex.
There are several molts and in the
End there is a dramatic
Metamorphosis.
There are 2 kinds of metamorphosis,
Complete and incomplete.

35. Complete
(egg— larvae— pupa—adult)

36. Incomplete

37. Tympanum (eardrum)

39. Subphylum Crustacea 31-4 Crustaceans Crayfish & lobster
Two pair antennae
10 footed
Pinchers used to obtain food
Two body sections (head & thorax are fused= cephalothorax)

40. THE END