1. Chapter 17 Section 4 notes

2. Characteristics of Arthropods:
More than 1 million species
Largest and most diverse group of animals
Jointed appendages (structures such as claws, legs, & antennae that grow from the body)
Exoskeleton-protects and supports the body and reduces water loss

3. Arthropods cont……
As the animal grows, the exoskeleton must be shed…called molting
Bilateral symmetry
7. Segmented bodies

4. Types of Arthropods: Insects – make up the largest group of
complex invertebrates
- have 3 body regions
(head-thorax-abdomen)
- open circulatory system

5. (2) Arachnids – predators - 2 body regions (cephalothorax & abdomen) - 4 pairs of legs (8 total) - EX….spiders, ticks, mites, & scorpions

6. (3) Centipedes & Millipedes - long, thin, segmented animals - centipedes (predators) have pairs of jointed legs attached to each segment - millipedes (eat plants) have 2 pairs of jointed legs attached to each segment

7. (4) Crustaceans usually have 2 pairs of antennae - 3 types of chewing appendages - 5 pairs of legs - swimmerets – force water over the feathery gills where carbon dioxide is exchanged for oxygen in the water - EX….crabs, crayfish, lobsters, shrimp, barnacles, etc….

8. Echinoderms Have radial symmetry
Have spines of various lengths that cover the outside of their bodies
Some are predators
Some are filter feeders
Some feed on decaying matter
Water-vascular system (network of water-filled canals & thousands of tube feet…work as suction cups to move or capture prey)
Regenerate lost or damaged limbs
EX……..sea stars (starfish), sand dollars, sea urchins