1. Chapter 26: Sponges and Cnidarians

2. 26-1 Introduction to the Animal Kingdom
What makes animals different from the previous organisms we have covered so far this year?

3. The Animal Kingdom Multicellular Eukaryotic Heterotrophs Cells lack
26-1 Introduction to the Animal Kingdom
The Animal Kingdom
Multicellular
Eukaryotic
Heterotrophs
Cells lack
cell walls
95% are
invertebrates

4. 26-1 Introduction to the Animal Kingdom

5. 26-1 Introduction to the Animal Kingdom

6. What Animals Do to Survive
26-1 Introduction to the Animal Kingdom
What Animals Do to Survive
Feeding
Respiration
Circulation
Excretion
Response
Movement
Reproduction

7. 1. Feeding Modes of ingestion of nutrients Carnivores Detrivores
26-1 Introduction to the Animal Kingdom
1. Feeding
Modes of ingestion of nutrients
Carnivores
Detrivores
Herbivores

8. 2. Respiration Taking in oxygen, releasing carbon dioxide Lungs Gills
26-1 Introduction to the Animal Kingdom
2. Respiration
Taking in oxygen, releasing carbon dioxide
Lungs
Gills
Skin

9. 3. Circulation Movement of materials in the body Diffusion Heart Pump
26-1 Introduction to the Animal Kingdom
3. Circulation
Movement of materials in the body
Diffusion
Heart Pump

10. 26-1 Introduction to the Animal Kingdom
4. Excretion
Removal of nitrogen waste out of body to maintain homeostasis
Diffusion
Kidney

11. 5. Response Responding to outside stimuli using nerve cells
26-1 Introduction to the Animal Kingdom
5. Response
Responding to outside stimuli using nerve cells

12. 6. Movement Attached to a single spot or motile
26-1 Introduction to the Animal Kingdom
6. Movement
Attached to a single spot or motile

13. 26-1 Introduction to the Animal Kingdom
7. Reproduction

14. Trends in Animal Evolution
26-1 Introduction to the Animal Kingdom
Trends in Animal Evolution
Though there are differences in whether an animal has a backbone or not, there are some common trends:
1. Cell Specialization
2. Body Symmetry
3. Cephalization
4. Body Cavity Formation

15. 26-1 Introduction to the Animal Kingdom
1. Cell Specialization
Animal cells have evolved to carry out specific functions:

16. 1. Cell Specialization Reasons why cell specialization is important:
26-1 Introduction to the Animal Kingdom
1. Cell Specialization
Reasons why cell specialization is important:
Allows for animals to perform many different functions
Causes a greater efficiency in survival

17. Early Embryonic Development
26-1 Introduction to the Animal Kingdom
Early Embryonic Development
Animals that reproduce sexually begin life after fertilization as a zygote (fertilized egg)
Zygote undergoes a series of divisions
Blastula forms (simple ball of cells)
Blastula fold in on itself forming blastopore
Blastopore leads into a central tube

18. Early Embryonic Development
26-1 Introduction to the Animal Kingdom
Early Embryonic Development

19. Protostome Animals mouth forms from blastopore (most invertebrates)
26-1 Introduction to the Animal Kingdom
Protostome Animals mouth forms from blastopore (most invertebrates)
Deuterostome Animals anus forms from blastopore
(echinoderms and vertebrates

20. Early Embryonic Development
26-1 Introduction to the Animal Kingdom
Early Embryonic Development
Endoderm inner
Mesoderm middle
Ectoderm outer
Cells differentiate into 3 germ layers

21. Early Embryonic Development
26-1 Introduction to the Animal Kingdom
Early Embryonic Development

22. 2. Body Symmetry Ability to divide a body into 2 equal halves
26-1 Introduction to the Animal Kingdom
2. Body Symmetry
Ability to divide a body into 2 equal halves

23. 2. Body Symmetry Planes of symmetry: Dorsovental Axis (Sagittal Plane)
26-1 Introduction to the Animal Kingdom
2. Body Symmetry
Planes of symmetry: Dorsovental Axis (Sagittal Plane)
Cuts the body into right and left sides

24. 2. Body Symmetry Planes of symmetry: Transverse Axis
26-1 Introduction to the Animal Kingdom
2. Body Symmetry
Planes of symmetry: Transverse Axis
Produces a “cross-section” of the body
Divides the body into “Anterior” and “Posterior” regions

25. 2. Body Symmetry Regions of the body: Dorsal: Upper
26-1 Introduction to the Animal Kingdom
2. Body Symmetry
Regions of the body:
Dorsal: Upper
Posterior: Rear End
Anterior: Front
Ventral: Lower

26. 26-1 Introduction to the Animal Kingdom
Trends of Evolution
There are two more characteristics that most animals share in addition to “Cell Specialization” and “Body Symmetry”
3. Cephalization
4. Body Cavity Formation

27. 26-1 Introduction to the Animal Kingdom
3. Cephalization
Refers to the characteristic that more sense organs and nerve cells are located at the anterior part of the body than anywhere else

28. 26-1 Introduction to the Animal Kingdom
3. Cephalization
Allows animals to respond quicker and in more complex ways to stimuli

29. 26-1 Introduction to the Animal Kingdom
4. Body Cavity Formation
Body cavity is a fluid-filled space that contains the organs

30. 26-1 Introduction to the Animal Kingdom
4. Body Cavity Formation
This allows space for internal organs to keep their shape and to grow properly

31. Evolutionary Relationships
26-1 Introduction to the Animal Kingdom

32. 26-2 SPONGES

33. Sponges Phylum Porifera
Have tiny openings, or pores, all over their bodies
Sessile: they live their entire life attached to a single spot
They are animals. Why…?

34. Click Picture To Watch a 3 Minute Sponge From and Function Video
26-2 Sponges
Sponges are Animals
Click Picture To Watch a 3 Minute Sponge From and Function Video
Multicellular
Heterotrophic
No cell walls
Contain a few specialized cells

35. Form and Function in Sponges
Have nothing resembling a mouth or gut
Have no tissues or organ systems
Simple functions are carried out by a few specialized cells

36. Asymmetrical Have no front or back ends, no left and right sides
26-2 Sponges
Asymmetrical
Have no front or back ends, no left and right sides
A large, cylindrical water pump
The body forms a wall around a large central cavity through which water flows continually

37. 26-2 Sponges

38. Specialized Cells Choanocytes Osculum
26-2 Sponges
Specialized Cells
Choanocytes
Specialized cells that use flagella to move a steady current of water through the sponge
Osculum
Water leaves through the large hole at the top of the sponge

39. 26-2 Sponges
Choanocytes
Specialized cells that use flagella to move a steady current of water through the sponge
Filters several thousand liters/day

40. 26-2 Sponges
Osculum
A large hole at the top of the sponge, through which water exits
The movement of water provides a simple mechanism for feeding, respiration, circulation and excretion

41. Specialized Cells spicule archaeocytes spongin
26-2 Sponges
Specialized Cells
spicule
is a spike-shaped structure made of chalklike calcium carbonate or glasslike silica
archaeocytes
are specialized cells that move around within the walls of the sponge and make spicules.
spongin
network of flexible protein fibers that make up the internal skeleton of a sponge.

42. 26-2 Sponges
Simple Skeleton
Spicule: a spike-shaped structure made of chalk-like calcium carbonate or glasslike silica in hard sponges
Archaeocytes: specialized cells that make spicules

43. 26-2 Sponges

44. Click Picture To Watch a 5 Minute Sponge Filter Feeding Video
26-2 Sponges
Sponge Feeding
Click Picture To Watch a 5 Minute Sponge Filter Feeding Video
Filter feeders
Sift microscopic food from the water
Particles are engulfed by choanocytes that line the body cavity

45. Respiration, Circulation, & Excretion
26-2 Sponges
Respiration, Circulation, & Excretion
Rely on the movement of water through their bodies to carry out body functions
As water moves through the cavity:
Oxygen dissolved in the water diffuses into the surrounding cells
Carbon dioxide and other wastes, diffuse into the water and are carried away

46. Response No nervous system
26-2 Sponges
Response
No nervous system
Many sponges protect themselves by producing toxins that make them unpalatable or poisonous to potential predators

47. Click Picture To Watch A 2 Minute Sponge Reproduction Video
26-2 Sponges
Reproduction
Click Picture To Watch A 2 Minute Sponge Reproduction Video
Sexually or asexually
A single spore forms both eggs and sperm; usually at different times

48. 26-2 Sponges
Sexual Reproduction
Internal fertilization: Eggs are fertilized inside the sponge’s body
Sperm are released from one sponge and carried by currents to the pores of another sponge

49. Asexual Reproduction Budding
26-2 Sponges
Asexual Reproduction
Budding
Gemmules: groups of archaeocytes surrounded by spicules

50. 26-2 Sponges
Ecology of Sponges
Ideal habitats for marine animals such as snails, sea stars, sea cucumbers, and shrimp
Mutually beneficial relationships with bacteria, algae and plant-like protists
Many are green due to these organisms living in their tissues

51. 26-2 Sponges
Ecology of Sponges
Attached to the seafloor and may receive little sunlight
Some have spicules that look like cross-shaped antennae
Like a lens or magnifying glass, they focus and direct incoming sunlight

52. 26-3 CNIDARIANS

53. Cnidarians Phylum Cnidaria Hydras, jellies, sea anemones, and corals
Soft-bodied
Carnivorous
Stinging tentacles arranged in circles around their mouths
Simplest animals to have body symmetry and specialized cells

54. Cnidocytes Stinging cells that are located on their tentacles
26-3 Cnidarians
Cnidocytes
Stinging cells that are located on their tentacles
Used for defense and to capture prey

55. 26-3 Cnidarians
Nematocyst
A poison-filled, stinging structure that contains a tightly coiled dart
Found within cnidocytes

56. Click Picture To Watch a 2 Minute Feeding Anemone Video
26-3 Cnidarians
Click Picture To Watch a 2 Minute Feeding Anemone Video

57. Click Picture To Watch a 3 Minute Stinging Jellyfish Video
26-3 Cnidarians
Click Picture To Watch a 3 Minute Stinging Jellyfish Video

58. Form and Function in Cnidarians
Only a few cells thick
Simple body systems
Most of their responses to the environment are carried out by specialized cells and tissues

59. 26-3 Cnidarians
Radially Symmetrical
Central mouth surrounded by numerous tentacles that extend outward from the body
Life cycles includes a polyp and a medusa stage

60. 26-3 Cnidarians
Body Plan
Polyp: cylindrical body with arm-like tentacles; mouth points upward
Medusa: motile, bell-shaped body; mouth on the bottom

61. Phylum Cnidarian 26-3 Cnidarians Medusa Polyp Tentacles Mesoglea
Epidermis
Mesoglea
Gastroderm
Tentacles
Mouth/anus
Gastrovascular cavity
Mesoglea
Gastrovascular cavity
Mouth/anus
Tentacles
Medusa
Polyp

63. 26-3 Cnidarians
Feeding
Polyps and medusas have a body wall that surrounds an internal space: the gastrovascular cavity
Gastrovascular cavity: a digestive chamber with one opening
Food enters and wastes leave the body

64. Respiration, Circulation, & Excretion
26-3 Cnidarians
Respiration, Circulation, & Excretion
Following digestion, nutrients are usually transported throughout the body by diffusion
Respire and eliminate wastes by diffusion through body walls

65. 26-3 Cnidarians
Response
Specialized sensory cells are used to gather information from the environment
Nerve net: loosely organized network of nerve cells that together allow cnidarians to detect stimuli
Distributed uniformly throughout the body in most species
In some species it is concentrated around the mouth or in rings around the body

66. 26-3 Cnidarians

67. 26-3 Cnidarians
Response
Statocysts: groups of sensory cells that help determine the direction of gravity
Ocelli: eyespots made of cells that detect light

68. 26-3 Cnidarians
Movement
Hydrostatic skeleton: a layer of circular muscles and a layer of longitudinal muscles that enable cnidarians to move

69. Reproduction: Sexually and Asexually
26-3 Cnidarians
Reproduction: Sexually and Asexually
Polyps can reproduce asexually by budding
External sexual reproduction
The sexes are separate-each individual is either male or female
Both egg and sperm are released into the water

70. 26-3 Cnidarians

71. 26-3 Cnidarians

72. 26-3 Cnidarians

73. Groups of Cnidarians Jellies (formerly jellyfishes)
Hydras and their relatives
Sea anemones
Corals

74. 26-3 Cnidarians

75. Groups of Cnidarians Class Scyphozoa: “cup animal” Jellyfish

76. Classes of Cnidarians Class Scyphozoa
Spend most of their lives as medusa
The polyp form is limited to a larva stage

77. Classes of Cnidarians Class Scyphozoa
The largest jellyfish ever found is 4 meters in diameter with tentacles more than 30 meters in length
Most species are harmless, many can cause servere allergic reactions/even kill people

78. 26-3 Cnidarians

79. 26-3 Cnidarians

80. Groups of Cnidarians Class Hydrozoa: Hydras; Portuguese Man of War

81. Classes of Cnidarians Class Hydrozoa
The polyps of most hydrozoans grow in branching colonies that sometimes extend more than a meter.
Within a colony, the polyps are specialized to perform different functions.
EX: One polyp forms a balloon-like float that keeps the entire colony afloat
Portuguese Man of War

82. Classes of Cnidarians Class Hydrozoa
Most common in freshwater hydrozoan is a hydra
Lack medusa stage (solitary polyp)
Reproduce sexually (producing eggs and sperm in the body wall) and asexually (budding)
a few species are hermaphroditic
Click Picture To Watch a 2 Minute Hydra Budding Video

83. 26-3 Cnidarians

84. Groups of Cnidarians Class Anthozoa: “flower animal”
Sea Anemones and Corals

85. Classes of Cnidarians Class Anthozoa
Grow only as polyps / no medusa stage
Central body that is surrounded by tentacles
Many species are colonial (composed of many individual polyps)

86. Classes of Cnidarians Class Anthozoa
Corals and sea anemones reproduce sexually by producing free swimming larvae
The free swimming larvae attach to rocks and then form polyps
Also can reproduce by budding

87. Classes of Cnidarians Class Anthozoa
Forming Coral Reefs
Formed when hard coral from layers of skeleton (CaCO3)
Algae forms a sybiotic relationship with coral

88. Click Picture To Watch a 1 Minute Coral Budding Video
26-3 Cnidarians
Click Picture To Watch a 1 Minute Coral Budding Video

89. 26-3 Cnidarians

90. Click Picture To Watch a 5 Minute Coral Spawn Video
26-3 Cnidarians
Ecology of Corals
The worldwide distribution is determined by:
Temperature
Water depth
Light intensity
Many suffer from human activity
Coral bleaching has become common
Global warming may add to the problem
Click Picture To Watch a 5 Minute Coral Spawn Video