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BIS2C: Lecture 28: Lophotrochozoans

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BIS2C: Lecture 28: Lophotrochozoans

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BIS2C: Lecture 28: Lophotrochozoans

  1. 1. Slides by Jonathan Eisen for BIS2C at UC Davis Spring 2016 Lecture 28: Triploblasts-Protostomes I: Lophotrochozoans BIS 002C Biodiversity & the Tree of Life Spring 2016 Prof. Jonathan Eisen !1
  2. 2. Slides by Jonathan Eisen for BIS2C at UC Davis Spring 2016 Where we are going and where we have been… •Previous lecture: •27: Diploblasts •Current Lecture: •28: Triploblasts: Protostomes: Lophotrochozonas •Next Lecture: •29: Triploblasts: Protostomes: Ecdysozoans !2
  3. 3. Slides by Jonathan Eisen for BIS2C at UC Davis Spring 2016 Animal Diversity Topics • Major Groups • Diversity within Groups • Key Features of Groups !Body Plans, Forms and Symmetry !Reproduction and Life Cycles !Mobility !Feeding • Examples !3
  4. 4. Slides by Jonathan Eisen for BIS2C at UC Davis Spring 2016 Lophotrochozoans • Key Features of Lophotrochozoans • Major Groups • Diversity within Groups • Examples !Molluscs !Annelids !4
  5. 5. Slides by Jonathan Eisen for BIS2C at UC Davis Spring 2016 Animal Diversity !5
  6. 6. Slides by Jonathan Eisen for BIS2C at UC Davis Spring 2016 Animal Diversity Diploblasts Triploblasts Monoblasts !6
  7. 7. Slides by Jonathan Eisen for BIS2C at UC Davis Spring 2016 Animal Diversity Monoblasts !7
  8. 8. Slides by Jonathan Eisen for BIS2C at UC Davis Spring 2016 Animal Diversity Diploblasts !8
  9. 9. Clicker !9Slides by Jonathan Eisen for BIS2C at UC Davis Spring 2016
  10. 10. Clicker Placozoans are really simple. Why don’t we place them at the base of the animal tree? Why do we believe the molecular phylogeny? A. Molecular phylogeny is more prone to homoplasy B. Appearances can be deceiving. C. Organismal complexity always increases over evolutionary time D. Sequences cannot undergo convergent evolution !10Slides by Jonathan Eisen for BIS2C at UC Davis Spring 2016
  11. 11. Clicker Placozoans are really simple. Why don’t we place them at the base of the animal tree? Why do we believe the molecular phylogeny? A. Molecular phylogeny is more prone to homoplasy B. Appearances can be deceiving. C. Organismal complexity always increases over evolutionary time D. Sequences cannot undergo convergent evolution !11Slides by Jonathan Eisen for BIS2C at UC Davis Spring 2016
  12. 12. Slides by Jonathan Eisen for BIS2C at UC Davis Spring 2016 Animal Diversity 12 Triploblasts
  13. 13. Slides by Jonathan Eisen for BIS2C at UC Davis Spring 2016 Animal Diversity 13
  14. 14. Slides by Jonathan Eisen for BIS2C at UC Davis Spring 2016 14
  15. 15. Slides by Jonathan Eisen for BIS2C at UC Davis Spring 2016 Lophotrochozoa !15
  16. 16. Lophotrochozoa Slides by Jonathan Eisen for BIS2C at UC Davis Spring 2016 Lophotrochozoa A lophophore circular or U- shaped ring of hollow, ciliated tentacles around the mouth. It Lophophorates !16
  17. 17. Lophotrochozoa Slides by Jonathan Eisen for BIS2C at UC Davis Spring 2016 Lophotrochozoa A trochophore is a specialized, free-swimming larval stage. Moves and pulls in food by beating a band of cilia. !17
  18. 18. Lophotrochozoa !18Slides by Jonathan Eisen for BIS2C at UC Davis Spring 2016 Lophotrochozoa Zoa = Animal
  19. 19. !19Slides by Jonathan Eisen for BIS2C at UC Davis Spring 2016 Lophotrochozoa
  20. 20. A Few Summaries for Your Enjoyment … !20Slides by Jonathan Eisen for BIS2C at UC Davis Spring 2016
  21. 21. Figure 32.6 Flatworms Include Both Parasites and Free-Living !21Slides by Jonathan Eisen for BIS2C at UC Davis Spring 2016
  22. 22. Figure 32.7 Rotifers and Gastrotrichs !22Slides by Jonathan Eisen for BIS2C at UC Davis Spring 2016
  23. 23. Figure 32.7 Rotifers and Gastrotrichs (Part 2) !23Slides by Jonathan Eisen for BIS2C at UC Davis Spring 2016
  24. 24. Figure 32.8 Ribbon Worms !24Slides by Jonathan Eisen for BIS2C at UC Davis Spring 2016
  25. 25. Figure 32.9 A Brachiopod’s Lophophore !25Slides by Jonathan Eisen for BIS2C at UC Davis Spring 2016
  26. 26. Figure 32.10 Phoronids !26Slides by Jonathan Eisen for BIS2C at UC Davis Spring 2016
  27. 27. !27Slides by Jonathan Eisen for BIS2C at UC Davis Spring 2016 Lophotrochozoa
  28. 28. Not JUST for your enjoyment … !28Slides by Jonathan Eisen for BIS2C at UC Davis Spring 2016
  29. 29. Mollusks !29Slides by Jonathan Eisen for BIS2C at UC Davis Spring 2016 • Most diverse group of Lophotrochozoans •~90,000 species, both aquatic and terrestrial.
  30. 30. Mollusks: Main Features !30Slides by Jonathan Eisen for BIS2C at UC Davis Spring 2016 • Bilaterally symmetrical (secondary asymmetry), coelomate protostomes • Reduced coelom • Open or closed circulatory system • Body plan: mantle, foot, and visceral mass • Mouth with a radula (lost in some groups)
  31. 31. !31Slides by Jonathan Eisen for BIS2C at UC Davis Spring 2016
  32. 32. Mantle !32Slides by Jonathan Eisen for BIS2C at UC Davis Spring 2016 • Fold of tissue along the dorsal surface that covers the visceral mass and encloses the mantle cavity. • Secretes the shell (when present).
  33. 33. Foot !33Slides by Jonathan Eisen for BIS2C at UC Davis Spring 2016 • Large, ventral muscle mass. • Used for locomotion, burrowing, and feeding. • Modified as a siphon (bivalves) or tentacles (cephalopods).
  34. 34. Visceral Mass !34Slides by Jonathan Eisen for BIS2C at UC Davis Spring 2016 •Central mass that encloses digestive, circulatory, excretory, and reproductive organs.
  35. 35. Radula !35Slides by Jonathan Eisen for BIS2C at UC Davis Spring 2016 • Rasping organ used for feeding.
  36. 36. A Few Summaries for Your Enjoyment … !36Slides by Jonathan Eisen for BIS2C at UC Davis Spring 2016
  37. 37. Chitons !37Slides by Jonathan Eisen for BIS2C at UC Davis Spring 2016 Chitons: 1,000 species. Eight overlapping calcareous plates, surrounded by a girdle, protect the organs and muscular foot. Most are marine omnivores that scrape rocks with a radula. They cling tightly to rock surfaces with the large, muscular foot.
  38. 38. Gastropods !38Slides by Jonathan Eisen for BIS2C at UC Davis Spring 2016 Gastropods: snails, slugs, nudibranchs, limpets, abalones; 85,000 species. Most move by gliding on the foot, but in a few species it is a swimming organ. Nudibranchs and slugs have lost their shells. Many are toxic and have brilliant colors for warning (aposematic coloration). Others have camouflaged coloration. Land snails and slugs are the only mollusks that live in terrestrial habitats. The mantle tissue is modified into a highly vascularized lung.
  39. 39. Bivalves !39Slides by Jonathan Eisen for BIS2C at UC Davis Spring 2016 Bivalves: clams, oysters, scallops, mussels; 30,000 species. Have hinged, two-part shells. Many use the foot to burrow into mud or sand. Feed by bringing water in the incurrent siphon and filtering food particles with large gills; water exits through the excurrent siphon.
  40. 40. Not JUST for your enjoyment … !40Slides by Jonathan Eisen for BIS2C at UC Davis Spring 2016
  41. 41. Mollusk Example: Cephalopods !41Slides by Jonathan Eisen for BIS2C at UC Davis Spring 2016 • Cephalopods: squids, octopuses, nautiluses; 800 species. • Excurrent siphon modified to eject water pulses allowing “jet propulsion.” • Head with complex sensory organs. Eyes are comparable to those of vertebrates. • Head has arms and/or tentacles (modified from food) used for predation and movement. • Most retain a small internal shell for internal support. • Octopuses completely lost shells • Many intelligent w/ complex communications
  42. 42. Cephalopods: Vision !42Slides by Jonathan Eisen for BIS2C at UC Davis Spring 2016 • Single lens eye, very similar to vertebrates
  43. 43. Cephalopods: Outward Appearance Modification I !43Slides by Jonathan Eisen for BIS2C at UC Davis Spring 2016
  44. 44. Slides by Jonathan Eisen for BIS2C at UC Davis Spring 2016
  45. 45. Cephalopods: Outward Appearance Modification II !45Slides by Jonathan Eisen for BIS2C at UC Davis Spring 2016
  46. 46. Slides by Jonathan Eisen for BIS2C at UC Davis Spring 2016
  47. 47. Slides by Jonathan Eisen for BIS2C at UC Davis Spring 2016
  48. 48. Annelids !48Slides by Jonathan Eisen for BIS2C at UC Davis Spring 2016 • ~ 19,000 species, marine and terrestrial • The coelom in each segment is isolated from the coelom in other segments. • A separate nerve ganglion controls each segment. • Most have a thin, permeable body wall that serves for gas exchange; restricted to aquatic or moist habitats. .
  49. 49. Annelid Example: Pogonophorans (Bearded Worms) !49Slides by Jonathan Eisen for BIS2C at UC Davis Spring 2016
  50. 50. Hydrothermal Vent 50Slides by Jonathan Eisen for BIS2C at UC Davis Spring 2016 (Image from Dive and Discover, WHOI) Deep Ocean Seawater Seafloor
  51. 51. Scientists Expected Little Life There 51Slides by Jonathan Eisen for BIS2C at UC Davis Spring 2016 • No light • Very high pressure • Low temperatures • Very little food • New seafloor
  52. 52. !52Slides by Jonathan Eisen for BIS2C at UC Davis Spring 2016 http://nationalgeographic.org/media/deep-sea-hydrothermal-vents/
  53. 53. Teeming Ecosystem !53Slides by Jonathan Eisen for BIS2C at UC Davis Spring 2016
  54. 54. Clicker Tubeworm symbionts fix carbon dioxide using energy and electrons from hydrogen sulfide (H2S). This makes them A. Chemolithoheterotrophs B. Chemoorganoheterotrophs C. Chemoorganoautotrophs D. Chemolithoautotrophs E. None of the above !54Slides by Jonathan Eisen for BIS2C at UC Davis Spring 2016
  55. 55. Clicker Tubeworm symbionts fix carbon dioxide using energy and electrons from hydrogen sulfide (H2S). This makes them A. Chemolithoheterotrophs B. Chemoorganoheterotrophs C. Chemoorganoautotrophs D. Chemolithoautotrophs E. None of the above !55Slides by Jonathan Eisen for BIS2C at UC Davis Spring 2016
  56. 56. Component Different Forms Energy source Light Photo Chemical Chemo Electron source (reducing equivalent) Inorganic Litho Organic Organo Carbon source Carbon from C1 compounds Auto Carbon from organics Hetero Forms of nutrition (trophy) Three main components to “trophy” Slides by Jonathan Eisen for BIS2C at UC Davis Spring 2016
  57. 57. Tubeworm Anatomy 57Slides by Jonathan Eisen for BIS2C at UC Davis Spring 2016 No Mouth No Digestive Tract No Anus Basic Tubeworm Anatomy But how can they eat with no mouth, gut, or anus?
  58. 58. Colleen Canavaugh !58Slides by Jonathan Eisen for BIS2C at UC Davis Spring 2016
  59. 59. Filled with Bacteria 59Slides by Jonathan Eisen for BIS2C at UC Davis Spring 2016 Basic Tubeworm Anatomy Dr. Colleen Cavanaugh used microscopy techniques in 1981 and discovered billions of bacterial cells packed inside the tubeworm’s trophosome. 1011 bacteria per gram of trophosome!! Plume Trophosome
  60. 60. Pogonorphorans Pogonophorans live in tubes of chitin. Digestive tract has been lost. They take up dissolved organic matter from the substrate and have endosymbiotic bacteria in a specialized organ called the trophosome. Hemoglobin in the tentacles imparts red color. !60Slides by Jonathan Eisen for BIS2C at UC Davis Spring 2016
  61. 61. Pogonophoran's Pogonophorans were discovered in the twentieth century in the deep oceans. Largest are up to 2 meters long and live near deep hydrothermal vents. The endosymbiotic bacteria fix carbon using energy from the oxidation of H2S. !61Slides by Jonathan Eisen for BIS2C at UC Davis Spring 2016
  62. 62. Whale Fall Worms !62Slides by Jonathan Eisen for BIS2C at UC Davis Spring 2016 • Chemoautotrophs related to beard worms with similar features (no gut). • Live on ‘whale falls’ the decaying remains of whales. • Bacteria are able to metabolize bone and lipids.
  63. 63. !63Slides by Jonathan Eisen for BIS2C at UC Davis Spring 2016 http://video.nationalgeographic.com/video/hydrothermal-vents
  64. 64. Figure 32.11 Annelids Have Many Body Segments (Part 1) !64Slides by Jonathan Eisen for BIS2C at UC Davis Spring 2016
  65. 65. Figure 32.11 Annelids Have Many Body Segments (Part 2) !65Slides by Jonathan Eisen for BIS2C at UC Davis Spring 2016

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