Chapter 29 Simple Invertebrates

1. Chapter 29 Simple Invertebrates

2. 29-1 Sponges

3. Phylum Porifera: The Sponges

4. Evolutionary Milestone=Multicellularity Very ancient group (lineage =580 mya) • “Pore-bearers” • tiny pores all over body Cell level (no tissues nor organs)

5. Habitat • mainly salt water (shallow & deep) • Polar regions to tropics • sessile=no movement • colonial

8. D. Importance • home for worms, shrimp, and starfish • help clean-up ocean floor • used for bathing • produce medicines (Discodermalide-cancer)

9. E. Classification • Based upon what spiculesare made of

10. Class Calcarea -calcium carbonate spicules Grantia

11. Class Demospongia -largest class -household sponge -spicules = spongin

12. Class Hexactinellida -glass sponges

14. 29-2 Cnidarians

15. Includes: jellyfish, anemones, and corals • Evolutionary Milestone = tissues

16. Habitat • Mostly saltwater • Sessile and/or mobile • Colonial or solitary

17. Physiology Radial symmetry Soft body made of TISSUES Breathe thru diffusion Have 2 different forms, Medusa and Polyp

18. Tentacles • Surround the mouth • Contain cnidocytes • Contain a “harpoon” = nematocyst • Used for defense, feeding, and attachment

19. neurotoxins which cause “sting” • “Man-O-War” is fatal to humans

20. Extracellular digestion “Sac-in-a-sac” = eat and excrete wastes with mouth

21. 2 Body Plans 1. Polyp -cylindrical -anchored -may build up chitin or calcium carbonate “skeleton” -mouth points UP

22. 2. Medusae • Free-floating and umbrella shaped • Mouth points DOWN

23. Class Hydrozoa

24. Class Scyphozoa

27. Class Anthozoa

31. 29-3 Flat & Roundworms Most flatworms live in Aquatic environments.

32. Phylum Platyhelminthes • “Platy”=flat • flattened dorsal-ventrally Flatworms belong to the class Turbellaria. Body is not divided into segments like an earthworm. They, as all future animals, show Bilateral symmetry. Evolutionary Milestone = cephalization

33. Planarians

34. No circulatory/ respiratory systems -diffusion

35. Reproduction hermaphroditic; some CAN self fertilize sexual- mate and deliver sperm to other animal

36. asexual- regeneration--- can divide in half

37. Class cestoda is made up of a group Of parasitic flatworms commonly Called tapeworms. Tapeworms grow by producing a string of Rectangular body sections called Proglottids. Each proglottid can create a new worm. The longest tapeworm found in a human Was 40 feet!!

39. Phylum Nematoda: Roundworms free-living: soil & water Evolutionary Milestone Pseudocoelom

40. Nervous System • -simple-- no brain-- just a group of nerve cells (ganglion) Digestive System “Tube-in-a-tube” some carnivores others parasitic

42. C. Examples • 1. Ascaris- Intestinal Roundworm

43. 2. Hookworm-causes Anemia • anterior end is hooked • attach to small intestine and feeds on blood

44. 3. Pinworms-causes Anal Itch

45. 4. Trichinella-causes Trichnosis • live in S.I. of pigs and enters muscle tissues to form a cyst • eating undercooked pork • rare but most dangerous

46. 5. Filarial Worm- Causes elephantiasis • Mosquito = secondary host • Adult worm resides in lymphatic vessels • Block fluid and causes swelling

47. THE END