Arthropods and Echinoderms

1. Arthropods and Echinoderms Chapter 6 section 4

2. Arthropods • Largest and most diverse group of animals • Animals that have jointed appendages • Appendages: structures like claws, legs, and antennae that grow from body • Have exoskeletons • Hard body covering • Protects, supports, prevents water loss • Shed because body grows, skeleton doesn’t • Process called molting

3. Arthropods: Insects • Have three body regions– head, thorax, abdomen • Well-developed sensory organs– eyes, antennae • Head: holds sensory organs • Thorax: 3 pairs of jointed legs, one or two wings • Abdomen: divided into segments

4. Arthropods: Metamorphosis • Insects completely change body as they mature • Metamorphosis has 4 stages • Egg • Larva • Pupa • Adult • Figure 18 pg. 165

5. Arthropods Arachnids Centipedes & Millipedes • Have only two body regions • Have four pairs of legs attached to each region • Long, thin, segmented • Pairs of jointed legs attached to each segment • Millipedes have two pairs

6. Arthropods: Crustaceans • Usually have two pairs of antennae • Three types of chewing appendages • Five pairs of legs

7. Echinoderms • Radial symmetry • Means “spiny skin” • Have spines of various lengths that cover outside of body • Supported and protected by internal skeleton • Simple nervous system but no heads or brains

8. Echinoderms: water-vascular system • Network of water-filled canals and thousands of tube feet • Regenerate body parts • read pg. 170 for fun fact

9. Exit Ticket • Name three characteristics found in arthropods.