1. What is an Animal? Chapter 24
Animal Movie (15 min)

2. 24-1 Animal Characteristics
Eukaryotic
Multicellular
Heterotrophic
Mobile at some stage

3. Support Support Invertebrates – lack backbones
May have external skeleton- exoskeleton
May have internal skeleton – endoskeleton
Vertebrates – have backbones & endoskeleton

4. Animal Development Most have Sexual Reproduction
Egg + Sperm = Fertilization
Can be internal or external fertilization
Forms a single celled zygote
Undergoes cell division during cleavage to form two cells
Hermaphrodites – have both male and female reproductive parts

5. Cell Division Once it is two cells, now called an embryo
Cells keep dividing to form a hollow ball called a blastula
Cells begin to fold inward to form a gastrula, this forms an outer layer (ectoderm) and an inner layer (endoderm)
Ectoderm develops into skin and nervous tissue
Endoderm develops into digestive track and organs associated with digestion

6. Cell Division

7. Gastrulation

8. Tissue Development
Endoderm – inner layer that develops into digestive organs and the lining of digestive tract
Mesoderm - middle layer that develops into muscles, circulatory system, excretory system, and in some respiratory system
Ectoderm – outer layer that develops into nervous tissue and skin
Sea Urchin - Blastula

9. Germ Layer Development

10. 24-2 Animal Body Plans

11. See Page 699!

12. Symmetry
View of the left side of a bilaterally symmetrical animal.  Drawing by John Norton.

13. Symmetry
Asymmetry – no symmetry
Ex. Sponges

14. Radial Symmetry
Radial – can be divided along any plane through a central axis
Examples: Hydra and Jellyfish

15. Bilateral Symmetry
Bilateral – can be divided down its length into mirror images
Examples: Humans and dogs

16. Body Plans Acoelomate – has three body layers, but no cavity
Example – Flatworm
                     

17. Acoelomate

18. Pseudocoelomate
Pseudocoelomate – have three body layers, with a fluid-filled body cavity between the endoderm and mesoderm layers
Example: Roundworms

19. Pseudocoelomate

20. Coelomate
Coelomate – have three body layers, with a fluid-filled body cavity within the mesoderm layer
Examples – earthworms, insects, fish

21. Coelomate

22. Protostome vs. Deuterostome
Protostome animals develop the mouth first
Examples include earthworms and insects
Deuterostome animals develop the anus first
Examples include echinoderms and vertebrates

23. Chapter 24.3
Sponges, Cnidarians

25. Phylum Porifera Sponges: Invertebrates Sponges can live
to be 100+ years
old.
Yellow Tube Sponge

26. Porifera Body Structure
Asymmetrical
No Tissues (ecto-, endo-,
mesoderm)
Just two layers of cells
with a jelly-like
substance in between
Porus

27. Porifera Body Structure
Pore cells: These surround the pores on the outside of the sponge. The pores are where water and food enter the sponge
Epithelial cells: These are the outer ‘skin’ of a sponge. These cells can contract to close the pores, if needed
Collar cells: These line the inside of the sponge. These cells have flagella that cause the current of water

28. Sponge Anatomy

29. Porifera Body Strurcture
Spicules: Between sponge cells
Not cells
Make up the ‘skeleton’
support system
Sponge structure video
- sponge movie

30. Porifera Support Archaeocytes cells Can move and change shape
Involved in digestion
Make egg and sperm
Make spicules (small
needle-like structures)

31. Porifera Support
Some freshwater sponges can produce gemmules, a seedlike unit that can survive cold temperatures.
Spicules provide support.
Can be sharp (made of calcium carbonate matter)
Can be made out of silica
Can be more flexible (like the fibrous protein spongin)

32. Porifera Motility Larvae: Free-swimming
Adult Sponge: sessile, usually on the sea
floor

33. Porifera Feeding and Digestion
Filter feeder
- food particles pass through the pores.
- Particles cling to cells
- Cells digest food individually.

34. finger or eyed sponge
bright yellow sponge

35. Porifera Reproduction
Sexually
Most sponges are hermaphrodites, have both sexes, which help insure fertilization with sessile animals.
Most sponges are fertilized internally.
Sperm that is carried by water currents.
The larvae can swim for a few days until they attach to a surface.
Asexually
fragmentation
budding

36. 3 Classes/Types of Sponges
Demospongiae
spongin
Calcarea
calcium
Hexactinellida
silica

37. Sponge Review System Type Sponges System Muscular-Skeletal
A sponge is a hollow tube with many pores or openings. The skeleton is made of calcium carbonate, silicon or spongin spicules.
Digestion
A sponge takes in food via the water that flows through the pores.
Nervous
A sponge has a very low level reaction to the world around it and does not have a brain per se.
Circulation
A sponge has water flow in through the pores. The water contains the food and oxygen the sponge needs.
Respiration
A sponge takes in water through its pores, and then canals that move the water all throughout the sponge. Then the oxygen from the water is used.
Reproduction
A sponge reproduces by budding, fragmentation and also sexually.
Excretion
A sponge has carbon dioxide and other wastes removed as the water moves in and out through the pores.
Symmetry
A sponge is asymmetrical or has radial symmetry.
Coloration
A sponge is white, red, orange, green, yellow, brown, purple, black

38. Jellyfish and Sea Anemones
Cnidarians
Jellyfish and Sea Anemones

39. Jellyfish

40. Cnidarian Features Mostly marine organisms Radial symmetry
Two cell layers with only one body opening
Tissues made of ectoderm and endoderm
Simple nervous system called the nerve net
Obtain oxygen by diffusion

41. New Scyphozoan Jellyfish Discovered (May 2003)
Tiburonia granrojo (Big Red)
was taken during a remotely
operated vehicle (ROV) dive on
the Gumdrop Seamount off the
coast of California. Can be up
to 1 m in diameter. Lives
between m deep.

42. Sea Anemones
Coral Polyps

43. Cnidarian Digestion Cnidocytes
Stinging cells on tentacles that capture prey
Comprised of nematocysts
A capsule
A coiled, threadlike tube
Poison
Barbs, sharp enough to penetrate a crab shell

44. It only takes 3/1000ths of a second for the nematocyst to discharge

45. Cnidarian Reproduction
Asexual is through budding
Sexual reproduction is through fertilization of eggs and sperm
Can be internal or external fertilization

46. Cnidarian Reproduction
Two life stages of Cnidaria:
Medusa- floating
2. Polyp- sessile

47. Life Cycle of a Jellyfish

49. Cnidarian Classes/Types
Class Hydrozoa
Have both the polyp and medusa stages of life
Can form colonies
Two kinds:
1. Hydroids – hydra
2. Siphonophores – colonies
of hydra
ex. Portuguese Man of War

50. Colony of Hydra

51. Siphonophores

52. Portuguese Man of War
A Violet Snail eating a siphonophore

53. Cnidaria Types Class Scyphozoa- (jellyfish) Transparent
Medusa is dominant
Some jellyfish have fatal stings.

54. Cnidaria Types Class Anthozoa Polyp stage is dominant Live in colonies
Build protective calcium
shelters
Symbiotic with a
photosynthetic protist
Use tentacles to feed
1. Corals- live in colonies
2. Sea Anemone-Live individually

56. the phylum of stinging animals video
movie on coral reef

57. Mutualistic Cnidaria
Crab + Sea anemone= sea anemone grows on crab’s shell to protect crab and collect food scraps

58. Commensalism Cnidaria
Clown fish + Sea anemone = Anemone stings predators of clown fish but not the clown fish

59. Human Bone Surgery
Coral contains Hydroxyapatite which has the same composition as human bone.
The coral can be grafted onto human bones during:
Face reconstruction
Jaw reconstruction
Arm and leg surgery
Knee Surgery

60. Ctenophora
Comb jellies – are jelly-like with radial symmetrical bodies
They have no stinging cells with which to stun their prey, but they are voracious filter feeders
Eight rows of combs made of cilia for motion
Reminds me of the movie – The Abyss

61. Characteristics of Ctenophora
Radial symmetry
Multicellular, few tissues, some organs and organelles.
Body contains an internal cavity,a mouth, and anal pores.
Swims by means of plates of cilia (the combs)
Reproduction mostly sexual as hermaphrodites, occasionally asexual.
Has a well developed nerve net.
Has a distinct larval stage which is planktonic.
Lives in marine environments.
All are carnivorous.

63. Colloblasts
– Sticky threads used in prey capture

64. Data Analysis Lab Page 714