Zoology Lecture 10

  1. Since Cnideria have _____ surface-area-to-volume ratios, there are no special respiratory provisions and gas exchange is by _______
    • high
    • diffusion
  2. H2O circulated within the ______________ helps distribute ___________ and ________
    • gastrovascular chamber
    • respiratory gases
    • food.
  3. NH 3is lost by ________.
  4. Fresh water types like Hydrao smoregulate but we do not know how. just saying
  5. Polyp movement just saying
  6. In polyps (e.g., Obelia& Hydra) the muscle processes of the ___________ cells are oriented to form a layer of _________ muscle
    • epithelio-muscular
    • longitudinal
  7. While the those of the nutritive muscle cells form a _________ layer.
  8. The mesoglea acts as a __________ as does the water filled gastrovascularcavity.
  9. Think of the postural changes as acting on a cylider. When longitudal muscles contracct the cylinder gets shroter, when they expand it gets longer. When circular muscles contract it gets tighter, when they expand it gets wider
  10. Solitary polyps such as Hydra and anemones are capable of locomotion by “__________.”
  11. The _________ of many jellyfish confers neutral density on the animals.
  12. Should have slightly _________ density than seawater
  13. Heavier anions such as __________ replaced by _________
    • SO4 2-
    • Cl-
  14. Such an animal does not have to ________ to stay up in the H2O column.
  15. ______ _________ is an example
    Obelia medusa
  16. When Poly orchis stops jetting it ________
  17. The bell of Polyorchis ________.
  18. The _________ and __________ are responsible for the greater density than seawater
    • tentacles
    • manubrium
  19. This property allows it to fish with spread out tentacles. just saying
  20. Swimming in medusae?
    Swimming is by jetting that involves alternate expansion and contraction of the bell.
  21. In Polyorchisand Obelia,cells of the ____________ epithelium lack muscle processes.
  22. The epitheliomuscular cells of the subumbrella surface are arranged such that along the radial canals muscle processes are arranged ________.
  23. In each quadrant between radial canals the muscle processes are ______ and arranged _________.
    • striated
    • circularly
  24. Contraction of the _________ muscles forces water out of the bell.
  25. Elastic recoil of the mesoglea and probably limited contraction of the _______ muscles expand the bell.
  26. NS control of swimming just saying
  27. Rhythmic swimming activity under control of ________.
    nerve net.
  28. two __________ nerve rings found at the edge of the bell.
  29. specifically _________ neurons
  30. Up to ________ groups of pacemaker neurons
  31. What are statocysts
    • statocyst is a balance organ present in some aquatic invertebrates (Cnidarian).
    • It consists of a sac-like structure containing a mineralised mass (statolith) and numerous innervated sensory hairs (setae).
    • The statolith's inertia causes it to push against the setae when the animal accelerates.
    • Deflection of setae by the statolith in response to gravity activates neurons, providing feedback to the animal on change in orientation and allowing balance to be maintained.
  32. Obelia has which sensroy organ(s) __________________; Polyorchis """"" _________________
    • statocysts
    • photo receptors & statocysts
  33. Polyorchis photoreceptor just saying
  34. Cup shaped with two cell types
    • 1. Sensory cells
    • 2. Pigment cells
  35. Sensory cells have a ____________ structure
  36. Hydrozoa just saying:
    Integrated Taxonomic Information System (ITIS).
    However we will follow the three groupings of–
    Order Hydroida(not recognized by ITIS)–
    Order Siphonophora(ITIS –Siphonophorae)–
  37. Fig 6.11 and 6.13
  38. Siphonophora
  39. ___________ forms often referred as oceanic hydrozoans
  40. _________organism (contrast with supraorganism)
  41. Many morphs –hydroid forms list the three of them and functions
    • Gastrozooids– feeding and digestive functions
    • Dactylozooids– protective & food capture
    • Gonozooids– asexually producing medusae
  42. Medusoid morphs How many are there?
    5 of them
  43. Whats the first Medusoid morph? Whats their morphology and function
    • Nectophores–
    • swimming individuals consisting of bell & propels the whole colony
  44. Pneumatophores define them
    Pneumatophores -gas-sac floats, medusa bell enclosing a bladder with secreted gas.
  45. Oleocysts–define
    Oleocysts–medusa bell filled with oil
  46. Phyllozooids, or bracts define
    Phyllozooids, or bracts –defensive forms with batteries of nematocysts but derived from medusae.
  47. Gonophores define
    Gonophores –gonad-bearing individuals usually borne on gonozooids, rarely develop as free medusa.
  48. fig 6.15
  49. fig 6.16
  50. What three things did he label for hyrocorals
    • gastrozooid
    • dactylzooid
    • skeleton
  51. Scyphozoa just saying its time for these guys
  52. What ar these knwon as? Why?
    “True” jellyfish wherein the acraspedote medusa is the dominant stage.
  53. Mesoglea is __________ and important in __________
    • massive
    • buoyancy
  54. Gastro vascularcavity highly ___________
  55. how many gastric puches does it have?
    Stomach & four gastric pouches
  56. Septaledges in gastric pouches have ________ that carry batteries of __________.
    • filaments
    • nematocysts
  57. More intricate system of canals. Direction of H2O flow:
    Stomach → gastric pouches → adradialcanals → circular canal →interradial& periradialcanals →exhalent grooves on oral arms
  58. fig 6.7 gastrovascular system of schyozoans
  59. Define rhopalia and associated structures
    Rhopalia (singular: rhopalium) are small sensory structures of Scyphozoa (typical jellyfish) and Cubozoa (box jellies). In Aurelia they lie in marginal indententions around the bell and are flanked by rhopalial lappets. Specialized structures to sense light (ocelli) and perceive gravity (statoliths) are usually present. They also control the pace of swimming-muscle contraction.
  60. figure 6.8
  61. figure 6.9
  62. Gonads in floor of gastric pouches. Sperm liberated directly. Ova held in stomach through fertilization and early cleavage of zygote. Note: strobilating scyphistoma= strobila
  63. Cubozoa just saying
  64. The ________ with __________ symmetry is dominant stage in the life cycle.
    • medusa
    • tetraradiate
  65. Six to eight photoreceptors in each rhopalium. are any image forming?
    At least two are image forming eyes
  66. Anthozoa just saying
  67. Exclusively ________ forms that tend to exhibit _______ symmetry
    • polypoid
    • biradial
  68. __________ cells arranged in muscle bands
  69. Gastrovascularcavity divided by __________
  70. Whats special about Anthozoas tentcles
    Hollow tentacles
  71. Asexual reproduction by _________ or ________.
    • budding
    • fragmentation
  72. fig 6.19
  73. End
Card Set
Zoology Lecture 10
Zoology Lecture 10