Arthropoda Classification Phylum Arthropoda Subphylum Uniramia terrrestrial mandibulates

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)

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

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

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

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

Subphylum Chelicerata Class Arachnida Order Araneae

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

Most have 8 eyes

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.

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

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

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

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

Class Arachnida, Order Opiliones

Class Arachnida, Order Solifugae “camel spiders” Eremobates sp only grow to about 6 inches https: //www. youtube. com/watch? v=G 7 fy. L A_GGc 4

Class Arachnida, Order Amblypygi “tailless whip scorpion”

Class Arachnida, Order Scorpiones Paninus imperator (Emperor scorpion)

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

Class Arachnida, Order Acari Mites and Ticks • Bodies fused into unsegmented ovoid shapes • Ticks (blood sucking parasites of vertebrates) transmit many different diseases o. Rocky mountain spotted fever o. Lyme disease • Mites transmit some diseases - mainly just irritants http: //www. idph. state. il. us/envhealth/pcmites. htm

Class Arachnida, Order Acari Rhipicephalus sanguineus Brown dog tick Dermacentor variabilis American dog tick Rocky mountain spotted fever http: //www. cdc. gov/rmsf/index. html

Class Arachnida, Order Acari Ixodes scapularis Deer tick http: //www. cdc. gov/lyme/ Lyme disease

Class Arachnida, Order Acari Class Sarcoptes scabiei scabies mite Eutrombicula alfreddugesi Chiggers are unique among mites affecting humans and animals, in that the immature stage (the larva) is the only parasitic stage. http: //www. cdc. gov/parasites/scabies/index. html

Subphylum Chelicerata Class Pycnogonida

Subphylum Chelicerata Class Merostomata Limulus limus – horseshoe crab

Subphylum Chelicerata Class Merostomata Spawning http: //www. youtube. com/watch? v=w. A-No. H_G 330 Drug Purification Testing http: //www. youtube. com/watch? v=90 LTt. KIFY 8 U