most diverse group of invertebrates (1,130,000 species) 75% of all animal species jointed appendages – important characteristic - adapted for walking, feeding, sensing, and mating

hard, thick, and made out of a carbohydrate called chitin land arthropods must have a waxy layer to protect against water loss

Molting = shedding of the old exoskeleton molts need to occur for arthropod to increase in size or add appendages (legs) new, softer exoskeleton forms underneath old skeleton new exoskeleton will harden overtime

3 fused segments: 1. head 2. thorax 3.abdomen ( fusion allows for better movement and protection) some arthropods have a fused head and thorax called a cephalothorax

Three types: 1.Gills - aquatic arthropods 2. Book lungs - spiders, horseshoe crab - leaf-like plates filled w/ air

3. Tracheal tubes - terrestrial insects - branching network of hollow air passages All respiration based on diffusion of gases (Oxygen/Carbon dioxide)

Antennae -- detect movement, sound and chemicals; used for communication (moth, mosquito, bee) pheromones --chemical odor signals can be given off for communication

Usually - one pair of compound eyes and 3-8 simple eyes simple eye = one lens used for detecting light compound eye = many lenses, detect movements and colors

Consists of 2 ventral nerve cords, anterior “brain”, and several ganglia ganglia serve as control centers for specific body sections

Open system, blood pumped by one or more hearts heartvesselstissuesheart (through open body spaces)

Complete gut mouth parts called mandibles (jaws) adapted for chewing, holding, sucking, or biting spiders have chelicerae, 1 st appendage adapted for piercing or fangs spiders and crustaceans also have pedipalps, used for holding food, sensing, and even mating

Insect Digestive Tract  Esophagus  Crop  Gizzard  Salivary gland  Gastric ceaca  Midgut  Intestine  Rectum  anus

Use Malphigian Tubules located in abdomen empty into intestine

Muscles attached to inner surface of exoskeleton External fertilization– aquatic (water) Internal fertilization– terrestrial (land) some species exhibit parthenogenesis (asexual reproduction—new insect develops from an unfertilized egg.) ex. Bees, ants, wasps

Incomplete Metamorphosis egg, nymph, adult

Grasshopper Anatomy  omalea.html omalea.html omalea.html  resources/dissection+activities+and+resou rces/grasshopper+dissection.do resources/dissection+activities+and+resou rces/grasshopper+dissection.do resources/dissection+activities+and+resou rces/grasshopper+dissection.do  Above is excellent picture  62InsectMorphology/Morph03.htm

 pper-movie.htm pper-movie.htm pper-movie.htm   y/Arthropo/Default.php?FlashLabModule.s wf?&Loadmoviename=../ArthTrac/Inse_Ho pp_05_lb.swf?E?Md2ChapterMcp1?Md2C h4SectionMcp1?Md2Ch4Sc2TopicMcp1

 1/bio11/units/ecology/grasshopperdissecti onlab.PDF 1/bio11/units/ecology/grasshopperdissecti onlab.PDF 1/bio11/units/ecology/grasshopperdissecti onlab.PDF  Above anatomy of digestive tract