Chapter 10 Section 2

1. Chapter 10Section 2 Arthropods

2. Characteristics of Arthropods • Four major groups • Crustaceans • Arachnids • Centipedes and Millipedes • Insects • Shared characteristics • Invertebrates • External skeleton • Segmented body • Jointed attachments called appendages (wings, mouthparts, legs)

3. Outer Skeleton • Exoskeleton • Waxy covering, or outer skeleton • Protects and helps prevent evaporation of water (adaptation) • When an arthropod grows… • Molting occurs • Molting: process of shedding an outgrown exoskeleton • New exoskeleton is soft for a little while, less protection

4. Segmented Body • Bodies made up of many identical-looking segments • Easily seen on millipedes and centipedes • Normally three sections • Head, midsection, and a hind section

5. Jointed Appendages • Your fingers! • Give the animal flexibility and enable it to move • Use legs to move, catch prey, defending, against predators • Use antenna, has sense organs for smelling, tasting, and touching

6. Crustaceans • Shrimp, crabs, crayfish, lobsters • Thrive in freshwater lakes and rivers • Two or three body sections • Five or more pairs of legs • Two pairs of antennae • Get oxygen from gills • Life Cycle • Crustaceans begin their lives as microscopic, swimming larva and develop into adults by metamorphosis (a process by which an animal’s body undergoes dramatic changes in form during life cycle)

7. Arachnids • Spiders, Mites, Scorpions, Ticks • Two body sections (first body section=head and midsection, hind section=abdomen) • Four pairs of legs • No antennae

8. Arachnids

9. Centipedes and Millipedes • Have two body sections and many pairs of legs • Centipedes • One pairs of legs attached to each segment • Sometimes more than 100 segments • Predators that inject venom into prey • Millipede • Two pairs of legs attached to each segment • Sometimes more than 80 segments • Scavengers