1. Chapter 29: Mollusks and Annelids
What is a mollusk?
What is an annelid?

2. Mollusks

4. Objectives:
Describe the skeletal structure, fertilization, reproduction, body symmetry, body coverings and locomotion for the Phylum Mollusca and Phylum Annelida
This will be completed through spreadsheet notes…..

5. How are annelids and mollusks related?
Both were the first major groups of animals to develop:
true coelom. – they have a body cavity, the gut and the rest of the organs are cushioned by the fluid in the coelom.
trocophore: a larval stage develops from egg, in some species it is free swimming and propels itself with cilia.

6. Trochophore: Free swimming larval stage of mollusks and annelids

7. Seven classes of mollusks make up phylum Mollusca
Three largest classes and examples are:
Gastropods- snails and slugs
Bivalvia- clams, oyster, and scallops
Cephalopoda- octopuses and squids

8. Know the 6 Key Characteristics of Mollusks
1. Body cavity: true coelom
2. Symmetry: bilateral symmetry
3. Three-part body plan: visceral mass- central part, mantle- outer layer of body, foot- muscular region used for locomotion
4. Organ systems- excretion, circulation, respiration, digestion, reproduction
5. Shell- one or two shells (most)
6. Radula- tongue like organ in the mouth, thousands of teeth on radula scrap off food and pull in prey.

9. Animal
Skeletal structure
Phylum Mollusks:
3 part body plan most have shells, (foot, visceral mass, mantle)

10. Fertilization and Reproduction: Mollusks
has reproductive system, male and female individuals, some hermaphrodites

11. Important Features : Mollusks
organ systems for excretion circulation, respiration, reproduction, two ends to digestive tract, radula for feeding

12. Body symmetry: Mollusks
most bilateral

13. Body coverings: Mollusks
most have either one or two shells, mantle of tissue covering body

14. Locomotion: Mollusks
muscular "foot" used to dig, slide, jump

15. Mollusk - Gastropods Examples: snails, slugs

16. Fertilization and Reproduction for Gastropods: same as mollusks

17. Important Features (look in this column and fill in for gastropods)
have organ systems for excretions, circulation, respiration, reproduction, two ends to digestive tract, radula for feeding
same as mollusks, pair of tentacles on head with eyes at tips

19. Body symmetry of gastropods is bilateral

20. Body coverings of gastropods are a mantle of tissue covering the body, spiral shells

21. Locomotion of Gastropods:"foot", secretes mucus it glides on

22. Bivalves: Examples: clams, oysters, scallops (all the notes for the next 6 slides are in the bivalve row)

23. Bivalve skeletal structure:
All have two part hinged shell
Giant clams can weigh more than 227 kilograms (500 pounds), and are the largest bivalve mollusk in the world.

24. Fertilization and Reproduction of Bivalves:
sexually, release sperm and egg into water, fertilized eggs become trocophore larvae

25. Important features of Bivalves:
filter feeders, through siphon tube, over gills out other siphon tube

26. Body symmetry of bivalves is bilateral

27. Body coverings of bivales: two part hinged shell, two thick adductor muscles connect shells

28. Locomotion of bivalves: most sessile, some swim opening/closing valves quickly

29. Cephalopod examples: squids, octopuses, cuttlefish, nautilus

30. Cephalopod skeletal structure: large head attached to tentacles, lack external shell,

31. Cephalopod reproduction: Sexual

32. Cephalopod body symmetry: bilateral

33. Cephalopod body coverings: only nautilus has shell

34. Cephalopod locomotion: jet propulsion

35. Animal
Skeletal structure
Annelids:
segmentation, setae: bristles, some have parapodia: fleshy appendages

36. Annelids:

37. Fertilization and Reproduction of Annelids:
hermaphrodites, reproduce sexually

38. Important features of annelids: respire through skin, have closed circulatory system, complex nervous system

39. Body symmetry of Annelids: bilateral

40. Body coverings of annelids: setae: bristles, some have parapodia: fleshy appendages

41. Body coverings of annelids: setae: bristles, some have parapodia: fleshy appendages

42. Locomotion of annelids: fluid filled compartment aids with contracting, stretching to move

43. Marine worms: Examples feather dusters, Nereis

44. Marine worm skeletal structure: Many parapodia

45. Marine Worm Reproduction: Hermaphrodites, sexual

46. Marine worm special features: some burrow, others live in protective tubes, some feed by pumping water through body

47. Body symmetry of Marine worm: Bilateral

48. Body coverings and locomotion of marine worms: many parapodia, use parapodia to swim, burrow or crawl

49. Earthworms skeletal structures: no parapodia, only setae

50. Fertilization and Reproduction of Earthworms
hermaphrodites, reproduce sexually

51. Important Features of Earthworms: eat their way through soil

52. Symmetry, body coverings, locomotion of Earthworms:
bilateral
few setae on each segment
fluid filled compartment aids with contracting, stretching to move

53. Leeches Skeletal Structure and Reproduction:
LeechesExamples:
suckers on both ends of body, flattened body
hermaphrodites, reproduce sexually

54. Important Features, Symmetry and Body covering of Leeches
most species predators or scavengers
bilateral
lack both setae and parapodia

55. Locomotion of Leeches: contraction and elongation of body

56. Let’s Review!
Get out the worksheet titled Invertebrate Review: Cnidarian, Annelids, Molluscs

57. We have covered the Phylum of Sponges, Cnidarians, Annelids, and Mollusks
Over the next few slides, determine what phylum the animal is classified.
Write the name of the animal under the correct heading on your worksheet.
Write a sentence about the characteristics of each animal.

58. Slide 1: Earthworm- look at the example of the sentence for characteristics.

59. Slide 2: Sea Anemone Characteristic example: all polyps, have tentacles

60. Slide 3: Sponge Characteristic: Is asymmetrical, is sessile

61. Slide 4: hydrozoan has stinging tentacles, radial symmetry, formed of both polyps and medusa

62. Slide 5: gastropod, has a single shell or no shell

63. Slide 6: Leech suckers on both ends of body, segmented flattened body

64. Slide 7: cephalopod has 3 part body plan, organ systems, radula

65. Slide 8: Feather Dusters have many parapodia, segmentation,

66. Slide 9: Scyphozoan has both polyp and medusa stage, radially symmetric

67. Slide 10: Bivalve two part hinged shell, bilateral, filter feeder

68. Slide 11: Sponge have spicules and spongin for support

69. Slide 12: Sponge have ostia and oscula as body coverings

70. The Walrus and the Carpenter enjoyed Bivalves…..

71. End of Critter Quiz! Pass in your slide show notes Pass in your quiz
Ready for a movie and quiz?

72. Humans are big fans of bivalves too.

73. Buried Bivalve

74. Marine Bivalves

75. 1. What class of animals are they!

76. Giant Squid – a cephalopod

77. Nautiluses - Cephalopods

78. Pearly Nautilus

79. Cuttlefish

80. Octopus - cephalopods