1. Arthropods and Echinoderms Biology I: Chapter 28

2. ARTHROPODS

6. Arthropods Phylum Arthropoda Insects, crabs, centipedes, spiders Segmented body Tough exoskeleton made of chitin Jointed appendages

7. Evolution of Arthropods Fewer body segments Highly specialized appendages for feeding, movement and other functions

9. - movement strategies

11. Form and Function in Arthropods Complex organ systems; some only found only in this phylum Tracheal tubes (respiration) Open circulatory system Excrete wastes through saclike tubules

13. Herbivores, carnivores, omnivores, bloodsuckers, filter feeders, detritivores, and parasites Mouthparts have evolved to allow them to eat anything imaginable Pincers or fangs to sickle-shaped jaws that can cut through the tissues of captured prey Feeding

15. mosquito centipede butterfly beetle squid spider

17. Respiration: Terrestrial Arthropods Tracheal tube: one of many branching, air-filled tubes that extend throughout the body Spiracle: small opening located along the side of the body through which air enters and leaves the body Book lung: organ that has layers of respiratory tissue stacked like the pages of a book: used to exchange gases

18. Respire through feather-like gills (i.e. lobster and crabs) The horseshoe crab respires through organs: book gills

19. Circulation Open circulatory system Well-developed heart pumps blood through arteries that branch and enter the tissues Blood leaves the blood vessels and moves through sinuses, or cavities The blood recollects in a large sinus surrounding the heart It reenters the heart and is again pumped throughout the body