1. Arthropoda
 Characteristics 

2. arthron = “joint” podos = “foot” Arthropod = Jointed Appendages
What is an Arthropod?
arthron = “joint” podos = “foot” Arthropod = Jointed Appendages

3. Jointed Legs Exoskeleton (Chitin) Segmented Bodies
Main Characteristics
Jointed Legs Exoskeleton (Chitin) Segmented Bodies
Bilateral Symmetry Dorsal Heart Ventral nerve cord
Excrete using Malpighian Tubules

4. Movement
Flex and Bend…
                                                         

5. Exoskeleton (hard outer skeleton)
ADVANTAGES
Protection
Attachment for muscles
Waterproof
DISADVANTAGES
Must be shed to get bigger (molt)
Defenseless during molting
Limits size of animal

6. Segmented Bodies
Made up of 2 or 3 parts…

7. Dorsal  & Ventral Nerve

8. Respiration (insects)
Spiracles = small openings on side of body – allows air to enter tracheal tubes

9. Respiration (spiders)
Book Lungs = folded membranes that increase surface area

10. Respiration (Aquatics)
Gills = use oxygen from water

11. Arthropods must molt to grow
=outgrow exoskeleton and “shed” it exoskeleton doesn’t grow with animal

12. Cicada molting

31. Arthropoda
 Diversity 

32. We Will Focus on 5 Subphylums of Arthropods
Crustacea (lobsters, crabs)
Arachnida (spiders, ticks)
Chilopoda (centipedes)
Diplopoda (millipedes)
Insecta (insects)

33. Crustaceans
Marine – shrimp, lobster, barnacles and crabs. Terrestrial – pillbugs and sowbugs Freshwater – crayfish and Daphnia (water fleas)

34. Crustacea (shrimp, lobster, crab, crayfish)
2 body segments – cephalothorax and abdomen
10 pair of jointed appendages
Breathe by gills
Jaws are mandibles for chewing or
tearing

36. The Largest Arthropod
Japanese spider crab

37. Crayfish
Carapace – protective covering Antennules – on head for balance, touch and taste Antenna – on head for touch & taste Maxillae – paired mouthparts to tear food Maxillipeds- help hold food

38. Chelipeds – claws used to capture food & protect
Mandibles – jaws that move side to side to crush food.
Walking legs
Swimmerets – swim, gas exchange & protect eggs

39. Crayfish dissection participation id MUST COMPLETE THE PICTURE ID FIRST
Swimmerets Chelipeds Antennules Antenna
Cephalothorax Abdomen Mandible Male or Female

41. Subphylum Chelicerata General Characteristics
6pairs of jointed appendages 1pair – chelicerae (fangs) 1pair – pedipalps 4 pairs walking legs
Cephalothorax and abdomen. No antenna Ocelli – simple eyes

42. Xiphosura – Classes of Chelicerae Horseshoe Crab Marine, not a crab
Book gills

43. Class Arachnida (spiders, ticks, scorpions, mites)
2 body segments
Cephalothorax/abdomen
4 pairs of walking legs = 8 legs on cephalothorax
Book lungs–gas exchange
8 simple eyes called ocelli
Carnivorous

44. Chelicerae
Also called fangs
Inject prey with
Poison.
No mandibles for chewing. Use extracellular digestion, digestive enzymes from mouth to turn prey into liquid. Spider “sucks” up the liquefied food.

45. Spinnerets
Spiders spin silk, but do not all make webs. Spider silk is secreted by silk glands in the abdomen. Spinnerets are located at the rear of the spider.

46. Ticks Other Arachnids Parasites Fused cephalothorax and abdomem
Needs blood “host”
Ticks carry Lyme disease and Rocky Mountain Spotted Fever

51. Class Chilopoda (centipedes)
1 pair of long legs PER segment Carnivorous – house centipedes eat cockroaches and other arthropods Quick moving Poisonous claws

52. Class Diplopoda (millipedes)
2 pairs of short legs PER segment
Slow/non-aggressive
Round body
Herbivorous scavengers
of woodland humus

53. Class Insecta (grasshopper, ants, butterflies, “bugs”)
Entomology – the study of Insects
Largest class of ALL animals on Earth!
70% of all animal species
3 body segments
3 pairs of walking legs = 6 legs
Go through Metamorphosis

54. Now let’s look into Metamorphosis…

56. Metamorphosis
Insects change from one stage of life to the next (larvae  adult)

57. Egg  Larvae  Pupa  Adult
Metamorphosis Cont.
Incomplete
3 stages
Egg  Nymph  Adult
Complete
4 stages
Egg  Larvae  Pupa  Adult

60. So let’s wrap it up…