1. Arthropoda Classification
Phylum Arthropoda
Subphylum Uniramia- (terrrestrial mandibulates)
Class Chilopoda- centipedes
Class Diplopoda- millipedes
Class Insecta- insects
Subphylum Crustacea- (aquatic mandibulates) lobsters, crabs, crayfish, shrimp, sow bugs (pill bugs), krill and barnacles
Subphylum Chelicerata
Class Arachnida- spiders, scorpions, ticks, and mites
Class Merostomata- horshoe crab
Class Pycnogonida- sea spiders
Subphylum Trilobita- trilobites (extinct)

2. Subphylum Chelicerata
~Named after mouthparts called chelicerae which appear as claws or fangs. They are used to pinch and pierce.

3. Remember Insects and Crustaceans are mandibulates
*Remember Insects and Crustaceans are mandibulates. They have mandibles which they use for chewing.

4. Ecological Impact Positive
Many arachnids help control the populations of many harmful insects
Negative
Harmful bites- spider
Harmful stings- scorpions
Transmit disease- ticks

5. Subphylum Chelicerata
1st pr of appendages are chelicera- mouthparts which may appear as claws or fangs
Tagmata- specialized grouping of multiple segments: cephalothorax & abdomen
4 pr of walking appendages
Respiration by book lungs
4 pair of simple eyes
No mandibles
No antennae
Fig. 18.CO

6. Subphylum Chelicerata Class Arachnida Order Araneae
Fig. 18.4

7. 6 Pair of Appendages
1 pair of chelicerae in the form of poisonous fangs
1 pair of pedipalps used for sensory reception and transfer of sperm in the male
4 pair of walking legs
No antennae

8. Most have 8 eyes

9. Feeding
Fangs immobilize prey and then the spider injects digestive juices into the victim
Later the spider sucks up the partially digested tissues of the prey
Some spiders produce silk webs used to catch food
Silk glands produce a protein secretion that hardens when it contacts the air
Spinnerets- 2 or 3 pair of small projections at the posterior end of the abdomen where silk comes out.

10. Respiration
Book lungs- air enters through a slit in the abdomen and flows between the pagelike folds where oxygen and carbon dioxide are exchanged
Some spiders have tracheae- minute tubules that transport oxygen directly to tissues

11. Reproduction
Not hermaphroditic - separate sexes - female often larger than male
Pedipalps of male transfer sperm to seminal receptacle of female - Internal fertilization

12. Regional Poisonous Spiders
Poison is a neurotoxin
Lactrodectus mactans
Loxosceles reclusa
Poison destroys tissue

13. Golden Orb Spider/Garden Spider
Argiope aurantia
Tan Tarantula
Aphonopelma anax

14. Class Arachnida, Order Opiliones
Fig b

15. Class Arachnida, Order Solifugae
“camel spiders”
Eremobates sp
only grow to about 6 inches

16. Class Arachnida, Order Amblypygi
“tailless whip scorpion”

17. Class Arachnida, Order Scorpiones
Paninus imperator (Emperor scorpion)

18. Scorpions Pedipalps modified into pincers
Segmented abdomen with a poisonous stinger in its last segment

19. Class Arachnida, Order Acari
Mites and Ticks
Bodies fused into unsegmented ovoid shapes
Ticks (blood sucking parasites of vertebrates) transmit many different diseases
Rocky mountain spotted fever
Lyme disease
Mites transmit some diseases - mainly just irritants

20. Class Arachnida, Order Acari
Rhipicephalus sanguineus Brown dog tick
Dermacentor variabilis American dog tick
Rocky mountain spotted fever

21. Class Arachnida, Order Acari
Ixodes scapularis Deer tick
Lyme disease

22. Class Arachnida, Order Acari Class
Sarcoptes scabiei scabies mite
Eutrombicula alfreddugesi Chigger
Chiggers are unique among mites affecting humans and animals, in that the immature stage (the larva) is the only parasitic stage.

23. Subphylum Chelicerata Class Pycnogonida
Fig. 18.3

24. Subphylum Chelicerata Class Merostomata
Fig. 18.2a
Limulus limus – horseshoe crab

25. Subphylum Chelicerata Class Merostomata
Fig. 18.2b
Spawning
Drug Purification Testing