1. Multicellular & Tissue Levels of Organization

2. Porifera, Cnidaria & Ctenophora
Porifera – the most primitive animals
Cnidaria & Ctenophora – possess embryological tissue layers

3. Evolution of multicellularity
How did we get from single celled animal like protists to multicellular animals?....
Colonial hypothesis- dividing cells staying together or individual protists living in colonies
Syncytical hypothesis- large multi nucleated cell

4. Protist ancestor to the sponge?
Single celled choanoflagellate

5. Phylum: Porifera “Pore Bearing”

6. Characteristics Radial or Asymmetrical
3 cell types: pinacocytes, mesenchyme cells, choanocytes
Lined with flagellated cells for filter feeding into central cavity or series of chambers
Internal skeleton but no tissues or organs
multicellular
Asexual & Sexual reproduction
Aquatic (marine & fresh water)

7. Terminology Osculum – opening at the top where water exits
Spongocoel – large chamber
Ostia – pores in sides of sponge for incoming water
Epidermis – outer wall (made of Pinacocytes, thin flat tissue-like cells that contract)
Porocytes – regulate water circulation
Spicules – skeleton of calcium carbonate, slender rods 3-4 rayed; other substances – siliceous (glass) or spongin fibers; tough branching network

8. Choanocytes – flagellated collar cells lining the inside canals, maintain current of water, they trap and phagocytize food particles
Mesoglea (Mesenchyme) – gelatinous “connective tissue” layer between cells
Archaeocyte – free cells, may function in digestion, or secretion of spicules or collagen.

10. Shape/Size
Thin flat crust, vase-shaped, branched, or irregular

11. Colors Yellow, orange, green, purple
Their color fades quickly when removed from water

12. The Three Main Types of Sponges Asconoid Sponge: Simple Sponges
Small, shallow-water marine sponge
Vase/Tube-like (Greek for “bladder”)
*The Spongocoel is flagellated
EX: Leucosolenia

13. Sychonoid Sponge Look like larger Asconoids
Tubular body but body wall is thicker and more complex with canals
*The spongocoel and canals are flagellated
EX: Scypha

14. Leuconoid Sponge
Form large colonial masses each member having own osculum
*Flagellated chambers that lead to canals, then to osculum

15. Food Getting and Digestion
Feed on detritus, plankton, and bacteria
Choanocyte collar collects food with fingerlike microvili
Digestion (intracellular). Food particles will be phagocytised by choanocytes to or archaeocytes.

17. Respiration and Excretion
Diffusion

18. Reproduction Sexually
Monoecious – both male and female sexes are in one body (hermaphroditic)
Ova are fertilized by motile sperm (sperm arise from choanocytes)
Zygotes develop into flagellated larva

19. Asexually Regeneration – replacement of lost parts
Budding – external buds of tissue drop off of parent
Gemmules – internal buds (dormant), masses of cells that are encapsulated and survive periods of harsh conditions

20. Locomotion
Adult is sessile
Larva are flagellated

21. General Characteristics
Phylum Cnidaria
General Characteristics
Radial symmetry
Diploblastic
Cnidocytes – stinging capsules
Tentacles around mouth
Body sac-like – gastrovascular cavity
No blood, respiratory, or excretory organs
Network of nerve cells & fibers in body wall
Two body forms (polyp & medusa)

22. Radial & Biradial Symmetry
Most are Radial
Some are Biradial
Have no dorsal/ventral sides or no anterior posterior
Based on position of the mouth , oral end and opposite is aboral
Beneficial for sedentary animals because sensory receptors are evenly distributed around the body

23. Functions of Cells in Different Embryologic Layer
Ectoderm – becomes epidermis
Cells function to protect and gather food
Endoderm – becomes gastrodermis
Cells function for movement, coordination, digestion and absorbtion
Mesoglea Cells – jellylike layer between epidermis and gastrodermis

24. Functions of Cnidae Produces by cnidocytes Functions:
Attachment- have stick secrections that help anchor
Defense – spines that penetrate
Feeding – spines w/hollow tips to discharge paralyzing toxins
Fluid filled capsule with internal coiled hollow tube

25. Cnidocyte Operculum (lid) Barb (prickly spine)
Filament (whip like structure)
Cnidocil (trigger)

26. Functions of the Gastrovascular Cavity
Digestion
Exchange of respiratory gases
Metabolic waste
Discharge of gametes
All of the above enter and leave through the mouth

27. Nematocysts entangle and paralyze prey
Contractile cells in tentacles shorten & pull food in
Gland cells – secrete digestive enzymes
Nutritive –muscular cells
aide in movement and phagocytize food particles from gastrovascular cavity
Contract in peristaltic circular motions & push undigested material back out through the mouth

28. Skeleton – for support and movement
Hydrostatic skeleton & pressure from surrounding watery environment enables it to maintain shape
Their “water balloon like” skeleton allows them to bend and twist when attempting to catch prey

29. Epitheliomuscular cells make up most of the epidermis enabling it to expand to 25 – 30 mm or contract to a tiny gelatinous mass – help with contractions
Interstitial cells – becomes other cells when a need arises (like stem cells)… make nerve cells, gland cells, sperm, egg
Fully extended, its tentacles sweeping the water for its prey, the hydra reaches a height up to two inches.

30. Two body forms Medusa Polyp tentacles & mouth down
Dioecious and free swimming
Polyp
tentacles and mouth up
Asexual and sessile

31. Moving in their Environment
Polyps – somersault, inchworm, glide
Medusa – swim & float by water & wind currents

32. Nerve tissue Most primitive nervous elements in the animal kingdom
Interconnected 2 dimensional nerve net

33. Nerve cells Sensory cells Spread throughout body
Act with sensory organs to detect food
Act as brains
Sensory cells
Receive stimuli (chemical or tactile), nerve cells conduct impulse, then epitheliomuscular cells contract

34. Respiration & Excretion
Diffusion – large surface area to volume ratio allows for a short distance for all cells from the body surface

35. Dioecious Most house male and female organs in separate bodies.
Where is the asexual stage and where is the sexual stage?

36. Phylum: Cnidaria
Class: Hydrazoa

37. Hydrazoans Kingdom: Animalia
Phylum: Cnidaria (connected with nettle) nettle = stinging hairs
Class: Hydrazoa

38. 3 Unique Features of Hydrozoa
Nematocysts are only in the epidermis
Gametes are epidermal and released to the outside of the body rather than into the gastrovascular cavity
Mesoglea is largely acellular

39. Form and Function Habitat – freshwater
Polyp, tubular body (tentacles up)
Tentacles surround mouth to capture prey
Nematocysts (coiled filament) on the cnidocytes allow it to sting and paralyze prey
Cnidocytes – hold and produce nematocysts

40. Missing medusa stage Basal disc (bottom)
Secrets adhesives to stick to an object
Produces gas bubbles to float on
Bud
Gastrovascular Cavity
Epidermis
Gastrodermis
Basal Disc

41. With its tentacles, a hydra bud snares a Cyclops, a tiny, one-eyed crustacean, also named after an ancient Greek monster. The bell-shaped protrusion on the hydra's body (upper left) is a second hydra bud.
Tentacles curled, a hydra is ingesting its prey. Its mouth is at right.
The hydra is at rest, digesting its meal.

42. Mesoglea Statocyst Act as an elastic skeleton Small sac containing
Helps withstand great mechanical strain
Gives tentacles more flexibility
Statocyst
Small sac containing
CaCO3 moves in response to gravity

43. Physiology Usually has 6-10 tentacles around mouth (only opening)
Hypostome is the mouth between the tentacles
Basal disc - hydra’s “foot”
Mostly made up of skin: Epidermis – cuboidal cells outside

44. Reproduction Asexually
Budding – hydras “Mini Me” growing on the side of it; when the bud is large enough it falls off and becomes independent organism
Regeneration
One hydra bud somersaults away from its parent as another grows. Hydras often have four buds at a time.

45. Sexually
In the autumn
Different species may be dioecious or monoecious
Dioecous; eggs in ovary are fertilized by sperm shed in water, a cyst is formed around the embryo before releasing from parent (survive winter), hatch in spring

46. Feeding and Digestion Food – crustaceans, insect larvae, worms
Capturing process
Tentacles (nematocysts) harpoon prey
Paralyze it
Engulf with mouth
Gland cells discharge enzymes (extra cellular digestion)
Nutritive muscular cells draw in food with pseudopodia (intracellular digestion)

47. Locomotion Gliding Floating attached to gas bubble Somersaulting
Sessile –twist and turn to capture food

48. PHYLUM: CNIDARIA “Stinging nettle” CLASS: SCYPHOZOA Jellyfish

49. FYI…
Lion's Mane Jelly (Cyanea capillata)
World’s largest jellyfish! In the Arctic specimens reach 8 feet in diameter, local ones may exceed 36 inches.
Lion’s Mane stinging cells (nematocysts) are very potent and will cause a severe skin reaction. Jellyfish can sting people even after it is dead. Jellyfish stinging cells are sticky, they can stick to wood, buckets or shoes and deliver a nasty sting when touches

50. Class Scyphozoa from Greek skyphos "cup" and zoon "animal"
Jellyfish
Medusa stage – dominant stage
Umbrella shaped body with fringe of tentacles hanging down
Polyp stage is minute or absent
The jelly is 95-96% water

51. Rhopalium
Club shaped sense organ found in notch of scalloped edge between tentacles
Each rhopalium contains
a hollow statocyst used for balance
two sensory pits (olfactory)
sometimes oceli (photoreceptors)

53. Reproduction Dioecious Sperm swim to egg and zygote lodges on oral arm
Grows into ciliated larval planula
Planula settles on bottom to become polyp (scyphistoma)
By process called strobilation, buds off a series of saucer-shaped buds (ephyrae)
Buds grow into medusa

54. Tentacles
Have nematocysts to paralyze prey

55. Mouth Center of underside
Surrounded by four oral arms (lobes) used in food capture

56. Gastrovascular Cavity
Digestive canals branch throughout
Gonads are contained in pouches here
Nerve net and circular muscles coordinate rhythmical movements

57. FYI: The Portuguese Man-of-War technically is not a “jellyfish” (it does not belong to the class Scyphozoa, it is from the class Hydrazoa)

58. Class Anthozoa “flower animals”

59. Corals and Sea Anemones
marine polyps with no medusa stage and no cnidocil

60. Oral Disc
Crown of tentacles arranged in many circles around mouth; at the ends of the mouth are siphonglyph (ciliated grooves) that create water currents into and out of the mouth and down pharynx & maintain hydrostatic skeleton
Pedal disc - The “foot” of the sea anemone

61. Anemone locomotion Gliding Crawling Walking on tentacles Floating
Thrashing bodies

62. Gastrovascular Cavity
The mouth is the only opening to the anemone's sac-like gut (gastrovascular cavity)
Undigestable food (snail shells, etc.) taken in, must be eliminated back out the mouth
Gastrovascular Cavity #2

63. Reproduction Sexually
depending on the species may be dioecious or monoecious
depending on the species may
Release sperm into seawater in broadcast spawing OR
Sperm released by the male may fertilize eggs held in the female’s body
Asexually
regeneration
can reproduce by splitting in half (a process called fission)
Splitting off small pieces of tissue from the basal disc (a process called pedal laceration)… a whole anemone can gradually regenerate from even a fragment of tissue
Anemone larval stage
called the planula, is a solid ball of cells
Hair-like cilia on its surface propel it over the bottom or up into the water
When the planula finds a suitable surface, it adheres to the bottom and changes form to become a young polyp with mouth, tentacles, and gut
Since the adult anemones cannot move very far in their life, the planula is the most important dispersal stage in the life cycle of sea anemones.

64. Painted Anemone (Urticina crassicornis)  
Unable to sting through a persons skin
May live up to 60 years

65. Aggregating Anemone (Anthopleura elegantissima) common on rocks and in sandy areas
Competing colonies attack each other, forming a "no-mans-land" between them.

66. Coral Reefs
200 C or warmer water; large formations of calcium carbonate laid down by organisms over thousands of years

67. 1. Fringing Reef
Less than a quarter of a mile from shore

68. 2. Barrier Reef
Runs parallel to shore, has a wider and deeper lagoon

69. 3. Atoll Reef
Reef that circles a lagoon of water rather than an island

70. Here they are together…

71. Phylum Ctenophora (pronounced /tiːn.ou.fɔː(r)/) “comb bearing”
Marine forms with 8 rows of comblike plates used for locomotion
Examples: sea walnuts and comb jellies

72. Radial symmetry
Marine
Free swimming

73. Comb plates
Ciliated
Used to propel mouth end forward

74. Physiology Reproduction Nerve net
Statocyst (fluid filled sensory organ)
Two tentacles
Gastrovascular cavity
Reproduction
monoecious

75. Question time Are jellyfish monoecious or dioecious?
2. What is “scyphozoa” greek for?
3. What is the difference between a fringing reef and a barrier reef?
4. What does “ctenophora” mean?

76. 5. What are the collar cells in sponges called?
6. What is the term for the stinging cell in the hydra?
7. What is the function of spicules?

77. Question time Are jellyfish monoecious or dioecious? Dioecious
2. What is “scyphozoa” greek for?
cup animal
3. What is the difference between a fringing reef and a barrier reef?
Fringing – close to land, barrier – has lagoon between the reef and the land
4. What does “ctenophora” mean?
Comb bearing

78. 5. What are the collar cells in sponges called?
choanocytes
6. What is the term for the stinging cell in the hydra?
cnidocytes
7. What is the function of spicules?
structure