Arthropoda Arthropods have a segmented body, a tough exoskeleton, and jointed appendages. Exoskeleton is make up of chitin- a protein and a carbohydrate

CRUSTACEANS (lobsters, crabs, shrimp, crayfish, barnacles)

SPIDERS (Arachnids) and relatives (horseshoe crab, mites, ticks, scorpions)

INSECTS (“bugs”, centipedes, millipedes)

Environment  Crustaceans – mostly aquatic  Spiders and Insects – in all types of environments. Insect subphylum contains more species than ALL other groups of animals alive today Food Source  Include herbivores, carnivores and omnivores  Their mouthparts have evolved in ways that enable different species to eat almost any food you can imagine

Maintaining Homeostasis - Internal (Circulation, Respiration, Excretion)  Breath through a network of branching tracheal tubes, air enter and leaves the body through spiracles (small openings along the body)  Open circulatory system and a well developed heart  Waste leaves by Malpighian tubules- saclike organs that extract wastes from the blood and the add them to feces or digestive waste Maintaining Homeostasis – External (Response)  Have a brain, a well developed nervous system and sophisticated sense organs (eyes & taste)

Movement  Well-developed groups of muscles that are coordinated and controlled by the nervous system. Reproduction  Some internal fertilization (land)  Some external fertilization (water) Evolutionary Milestone  The evolution of arthropods, by natural selection, has led to fewer body segments, and highly specialized, jointed appendages for feeding, movement, and other functions.

Picture and Vocabulary  Pictures Fig 28-5 p.718 Fig p.727 Fig p. 729  Vocabulary: exoskeleton(715), appendage(715), molting719), metamorphosis (729)