Ch. 29

  Spiders, scorpions, mites, ticks, & horseshoe crabs  Have Chelicerae: a pair of appendages used to attack prey Subphyla Chelicerate

 Have 4 pairs of “walking legs” Cephalothorax Carnivores Only consume liquid food Injects with enzymes that turn the prey’s tissues into liquid  then they suck the liquid food into their stomach! Characteristics

 Spiders (Arachnids) Chelicera = fangs Black widow & brown recluse = POISONOUS! Spinnerets  appendages at the end of the abdomen that secrete sticky strands of silk Scorpions -Long, segmented abdomen that ends in a venomous stinger -Grasping pincers Groups

 Mites and Ticks -Single, unsegmented body -Some cause irritating bites (Ticks) Horseshoe Crabs -Appeared on Earth about 400 million years ago -Blue blood! Groups Cont.

Ch. 29.2

 Primarily marine Cephalothorax & an abdomen Mandibles for feeding 2 pairs of antennae Breathe by using gills Crustacean Characteristics

 Isopods (Pill bugs) Sand fleas Must be close to water for reproduction! Terrestrial Crustaceans

 Sessile (permanently attached to something) Crustaceans - barnacles Decapods = “Deca” + “pod” Shrimps, crayfish, crabs, & lobsters Cephalothroax 2 pairs of antenna used to “sense” Move through the water by contracting their abdominal muscles Aquatic Crustaceans