1. Annelids and Arthropods

2. Annelida (Segmented Worms)
Triploblastic, Protostomes, Bilateral Symmetry
Metamerism (repeating segments)
Closed Circulatory System, complete digestive system
Annelids include earthworms, bristleworms, and leeches

3. The Giant Gippsland Earthworm (Megascolides australis McCoy) is one of the largest earthworms in the world, with an estimated average length of 80 cm and a diameter of 2 cm (Yen et al. 1990).

5. Digestive System Mouth Pharynx Esophagus – with esophageal glands Crop
Gizzard
Intestine

6. Anterior – Dorsal view

7. Reproductive System
Earthworms are hermaphrodites – they possess both male and female structures.
Testes and ovaries produce sperm and eggs. The sperm is stored in the seminal vesicles (the most prominent structures).
During copulation, the two worms exchange sperm. They store their received sperm in the spermatheca (seminal receptacles).

8. Reproductive Structures up Close

10. Cross Section of Digestive Tract

11. Circulatory System An earthworm has a closed circulatory system.
5 pseudohearts pump blood through a system of closed blood vessels. Note the dorsal blood vessel running along the intestine…

12. Locomotion
Earthworms have both circular and longitudinal muscles in their body walls. These contract in regular patterns that allow for movement.
Earthworms also have setae (little grasping appendages) that anchor the worm during movement.

13. Intermission – can you do this?

14. Arthropods!
Arthropoda is the most diverse phylum on earth.  950,000+ species
The phylum includes insects, crustaceans, centipedes/millipedes, arachnids, trilobites, and horseshoe crabs.

15. Arthropod stats Triploblastic protostomes. Cephalization
Segmented body
Bilaterally symmetrical
Chitinous exoskeleton
Jointed appendages

16. Inside a Roach

17. Insecta Very successful for many reasons, a main one being flight.
Respiration: series of tubes called trachea run throughout body – these open to the outside through pores in the body wall called spiracles

18. Insecta Complete digestive tract with crop and gizzard.
Located near midgut (intestine) are Malpighian tubules. This is an excretory organ that filters the body fluid and excretes waste into the lumen of the digestive tract.
Insects don’t have blood – they have hemolymph – a common fluid that carries everything
Circulatory system is open – a pump circulates the fluid but there are no vessels

19. Inside a Crayfish

21. Spider Anatomy
Spiders are known for their fangs and ability to poison their victims with venom.
Also have a hydraulic skeleton – body fluid is pumped into various places to make the legs ‘move’

28. Millipedes vs. Centipedes
The way to tell the differences is the number of legs. Millipedes have 2 pairs of legs per segment and centipedes have only 1 pair.
Centipedes are predators – likely to be venemous. Millipedes are generally garden pests – though they can emit stinky secretions.

30. Trilobites (extinct)

31. Horseshoe Crabs
Thought to be one of the least changed and most ancient group of organisms.

32. Ringworm
Ringworm is a contagious fungus infection that can affect the scalp, the body (particularly the groin), the feet, and the nails. Despite its name, it has nothing to do with worms. The name comes from the characteristic red ring that can appear on an infected person's skin.

33. Mollusca and Echinodermata

34. Phylum Mollusca Protostomes Triploblastic Cephalization
Complete digestive system
Closed/Open circulatory system
Q: What are the defining features of the phylum?

35. Defining Features Mantle Shell Foot Radula Ctenidia
Q: What does each of these DO?

36. General Squid Anatomy

37. General Snail Anatomy

38. General Clam Anatomy

39. The Vampire Squid!
Vampyroteuthis infernalis

41. Echinodermata Deuterostomes! Radial symmetry as adults Endoskeleton
Specialized Water Vascular System for movement and feeding

43. Water Vascular System

44. Digestive System