1. Arthropods
By Aaron Williams

2. Characteristics Typical arthropod is segmented
They are bilateral symmetry, have an exoskeleton, and jointed appendages
Pollinate many of the plants on Earth
Molt because they out grow their exoskeleton
In most arthropods they have 3 body segments: head, thorax, and abdomen
Arthropods can exchange gas in 3 different ways: gills, book lungs, or tracheal tubes
Have well developed nervous system: double ventral nerve cord, anterior brain, and ganglia
Reproduce sexually, but some arthropods exhibit parthenogenesis which is a form of asexual reproduction

3. Arachnids Arachnids are spiders, scorpions, ticks, and mites
Arachnids have 6 pairs of limbs
First pair are called chelicerae, which is located near the mouth, often modified as fangs or pinchers
Second pair is called pedipalps, used for handling food and for sensing
The other 4 pairs are used for locomotion

4. Crustaceans
Includes crabs, lobsters, cray fish, pill bugs, shrimp, and barnacles
Exchange gas thru gills
Two compound eyes usually located on stalks
Most live in aquatic environments, if not, they are found in moist environments
Many have 5 pairs of walking legs
Have mandibles for crushing food

5. Chilopoda Chiloods are centipedes Have flattened bodies
Found in damp environments
Are carnivorous and eat soil arthropods
Have Malipighian tubules for waste excretion
Have tracheal tubes for gas exchange

6. Diplopoda Diplopods are millipedes
Eats mostly plants and dead material
Live in damp/moist environments
Have thousands of legs
Are able to spray obnoxious-smelling fluids to escape predators

7. Merostomata Merostomata are horseshoe crabs Found in oceans
Have been unchanged since the Cambrian period
4 known species
Migrate to shallow waters during mating season
Females lays their eggs on land, underneath the sand

8. Insecta
Includes butterflies, beetles, grasshoppers, bees, and a lot more
Largest group of arthropods
750,000 known species
Reproduce sexually and go thru metamorphosis “Incomplete and complete”