Subphylum Chelicerata Class Arachnida: Order Araneae

Subphylum ChelicerataClass Arachnida: Order Araneae

Distinguishing body features

Pairs of appendages which include:-Chelicerae- mouth parts-Pedipalps- used for sensory, food manipulation, mating- 4 Pairs of walking legs

Ceplalothorax (head+thorax)AbdomenPedicel

Additional body Characteristics

Claws at end of legs and Fangs at tipes of chelicerae

Poison Glands8 simple eyes to detect movement

Feeding

Spiders are predacious fluid feedersMost feed on insectsDifferent spiders chase, amush or trap prey in silk

Silk Production

Silk glands located in the abdomen2 or 3 pairs of spinnersThread is stronger then silkSilk may be used for:

websline netssperm webs or egg sacswrap preythrow nets

Reproduction

Male pedipalps deliver sperm to the female genitals Cocoon contains hundreds of eggsOn average it takes two weeks for eggs to hatchBabies remain for another three weeks developing

Humans and Spiders

Spiders are very timidHelp us battle insectsMost spider bites cause irritation

Example: Tarantula bite = to bee sting

Fatal Spiders

Latrodectus dectus aka black widowshiny, black body with red or orange hour glass

on ventral sideneurogenic venom affects nervous system

Loxosceles skelos aka brown reclusebrown with violin shape on anterior dorsal sidehemolytic venom affects blood and blood