Arthropods Arthropods Segmented body Tough Exoskeleton chitin Jointed

Arthropods

Arthropods �Segmented body �Tough Exoskeleton: chitin �Jointed appendages: appendages legs and antennae �Classified: �body segments and appendages �particularly mouth parts

Arthropods �With evolution: �fewer body segments �specialized appendages for feeding, movement, and other functions �Molting: sheds exoskeleton

Other Characteristics �Bilateral Symmetry �Feeding: herbivores, carnivores, omnivores �Circulation: Open-Circulatory System

More Info �Respiration: branched tracheal tubes or book lungs �Excretion: Malpighian tubes �Response to Stimuli: well developed �Movement: muscles contract & pull on exoskeleton �Ex: spiders, insects, crustaceans

Crustaceans Crayfish, Crabs, Lobsters, & Barnacles 2 pairs of antennae 2 or 3 body sections Mandibles: chewing mouthparts

Chelicerates Horseshoe Crabs, Spiders, Mites, Ticks, & Scorpions Mouthparts Chelicerae: fangs used to stab and paralyze prey Pedipalps: grab prey 2 body sections; 8 legs

Uniramians Centipedes, Millipedes, & Insects Jaws; 1 pair of antennae Unbranched appendages

Insects Body divided into head, thorax, & abdomen 3 pairs of legs

Metamorphosis �Process of changing shape and form �Incomplete: similar appearance through out life �Nymphs: lack functional sexual organs & wings �Complete �Larva: undergo finial molt pupa �Pupa Adult; completely different animal �Lady bugs, butterflies

Metamorphosis

Life as an Insect Pheromones: chemical messengers Signal alarm or death Male/female courtship Societies: group that works and lives together ants, bees, termites