1. Good Afternoon!
On a sheet of paper (it can be a half sheet) tell me 5 things that you remember about Jellyfish from the movie on Friday!
You will be turning this in 5 minutes after the bell rings 

2. Invertebrates
Phylum
Cnidaria

3. Cnidarians This term is not used often anymore!
Phylum Cnidaria
Includes jellyfish, anemones, corals, & sea pens
Next level of complexity after sponges
Tissues are specialized to perform specific
functions.
Also called coelenterates
This term is not used
often anymore!

4. Coelenterates Refers to 2 Phylums combined: Ctenophora: Comb Jellies
Even though not used often anymore…
Refers to 2 Phylums combined:
Phylum Cnidaria & Phylum Ctenophora
Ctenophora: Comb Jellies
Cnidaria: Jellyfish, Sea anemones, Corals, & Sea pens
Have a hollow body cavity, & very
simple tissue organization

5. Cnidarians Have NO bones Have NO heart Have NO brain
Have NO “real” eyes
Have NO respiratory system

6. Cnidarians: Body Plan
Display radial symmetry, which is a
regular arrangement of similar body parts around a central axis.
Look the same from all sides
Have no head, front, or back

7. Cnidarians: Body Plan
Have an oral surface where the mouth is & an aboral surface on the opposite side.

8. Polyp: A sac-like attached stage (sessile) Medusa: Bell-like stage
Occur as 2 basic forms:
Polyp: A sac-like attached stage (sessile)
Medusa: Bell-like stage
Some experience both forms during their life time, and others spend their entire lives as one of the two forms.
Medusa
Polyp

9. Cnidarians: Anatomy Have a centrally located mouth surrounded by
tentacles which are slender, finger like
extensions.
Use tentacles to catch & handle food

10. Cnidarians: Anatomy
The mouth opens into a gut (enteron) where food is digested.
- The gut has only one opening, the mouth.

11. This is how jellyfish got their name.
Cnidarians: Anatomy
The mesoglea is extremely thick, has a
jelly like consistency & makes up the
largest portion of the animal
This is how jellyfish got their name.

12. How Cnidarians Sting
At the narrow outer edge of the cnidocyte is a short trigger hair called a cnidocil (“trigger”).
Upon contact with prey, the contents of the nematocyst are explosively discharged, firing a dart-like thread containing neurotoxins.

13. How Cnidarians Sting
These stinging cells contain poison arrows connected to threads called nematocyts.
* Cnidarians can still sting when they are dead!!

14. Tentacles
They capture small prey by discharging their cnidocytes (stinging cells), which are unique structures found on the tentacles.

15. Tentacles
The tentacle then brings the victim to the mouth to be digested.
The food passes through the body cells, and the waste must go back out of the mouth.

16. Jellyfish Eating

17. Jellyfish Feeding Video Clip

18. Cnidarians: Anatomy 2 Layers of cells form the body wall
- Ectoderm: external layer
- Endoderm: internal layer that lines the gut

19. Feeding
Zooplankton: Drifting microscopic animals

20. Feeding
Phytoplankton: Drifting microscopic plants.

21. Gastrovascular Cavity: A digestive chamber with one opening.
Feeding
After paralyzing its prey, a cnidarian pulls the prey through its mouth and into its gastrovascular cavity.
Gastrovascular Cavity: A digestive chamber with one opening.
Food enters & waste leaves the body through
that opening.

22. Response to Environment
Cnidarians gather information from their environment using specialized sensory cells.
Both polyps & medusas have a nerve net.
Nerve Net: A loosely organized network of nerve cells that together allow cnidarians to detect stimuli such as the touch of a foreign object.

23. Response to the Environment
Cnidarians have statocysts which are groups of sensory cells that help determine the direction of gravity.
Ocelli are eyespots made of cells that detect light.

24. Movement
Hydrostatic Skeleton: consists of a layer of circular muscles & a layer of longitudinal muscles that together with the water in the gastrovascular cavity, enable the cnidarian to move.
Medusas move by jet propulsion.
Muscle contractions cause the bell-shaped body to close like a folding umbrella.
This action pushes water out of the bell, moving the medusa forward.

25. Cnidaria Reproduction
Some reproduce asexually by budding (in polyps)
Some reproduce sexually by releasing gametes.
Some sexual forms are monoecious and others are dioecious
Eggs and sperm are released into the stomach and then through the mouth into the sea.

26. Cnidaria Reproduction
In some cases, to reproduce, a male releases his sperm into the surrounding water (spawn).
The sperm then swims into the mouth of the female jellyfish, allowing the fertilization of the ova.

27. Cnidarian Reproduction
In other cases, sexual reproduction takes place with external fertilization in water:
External Fertilization: Takes place outside the body.
The male & female releases eggs
and sperm at the same time.

28. Jellyfish Review Video Clip

29. Types of Cnidarians
Class Hydrozoan

30. Types of Cnidarians: Hydrozoans
Class Hydrozoans
Hydra
They can be found in most unpolluted fresh-water ponds, lakes, and streams
They are usually a few millimeters long and are best studied with a microscope
Hydra has a tubular body secured by a simple adhesive foot called the basal disc.

31. Types of Cnidarians: Hydrozoans
Class Hydrozoans
Hydra
At the free end of the body is a mouth opening surrounded by one to twelve thin, mobile tentacles.
Hydras are generally sedentary
or sessile, but can move,
especially when hunting. 31

32. Types of Cnidarians: Hydrozoans
Hydra
They move by bending over and attaching themselves to the substrate with the mouth and tentacles & then release the basal disc.
The body then bends over and makes a new place of attachment with the foot.
They “inch-worm” or
“somersault” to move 32

33. Types of Cnidarians: Hydrozoans
Class Hydrozoans
Portuguese man-of-war
Consist of feather or bushy colonies of polyps.
- Some polyps are specialized floats, which
may be gas-filled
- Other polyps form the long tentacles used to
capture prey. 33

34. Types of Cnidarians: Hydrozoans
Portuguese Man-of-War

35. Types of Cnidarians
Class Scyphozoans

36. Types of Cnidarians: Scyphozoans
Class Scyphozoan
Includes jellyfish
Have a rounded body, or bell.
Swim w/ rhythmic contractions of the bell, but swimming ability is limited & are carried by ocean currents.

37. Class Scyphozoans 95% of body is made of water
Here before dinosaurs and sharks
Inhabit all oceans of the world

38. Moon Jellyfish also called Common Jellyfish

39. Moon Jellyfish Life Cycle
Planula
Each jellyfish is either male or female
1. Males release sperm into surrounding water
2. Eggs get suck in pits on the oral arms, and are fertilized by sperm
3. The egg develops into a planula
Planula is the larval stage, small, & covered in cilia
4. The planula settles on a hard surface & develops into a polyp to become sessile

40. Moon Jellyfish Life Cycle
5. The polyp begins reproducing asexually by budding, and now called a scyphistoma
6. Budding produces miniature medusae called ephyrae
7. After ephyrae are released, they gradually grow into adult forms

41. Jellyfish Reproduction

42. Class Scyphozoans: Importance
* Jellies are considered a delicacy by many people.
* Low in fat & calories
* Rich in nutrients.
* Others claim they taste like rubber bands.

43. Class Scyphozoans: Importance
* Food source for fish, sea turtles, and other organisms

44. Looks like a Jellyfish to sea, but isn’t!
Clear plastics (such as bags and balloons) are often mistaken for jellyfish by animals such as the endangered leatherback sea turtle. When they eat plastic, these animals will often starve to death as the plastic clogs their intestines and they can no longer digest food.

45. Save the Sea Turtles!
Recycle Plastic Bags & Make sure they do not find their way into the ocean!

46. Class Cubozoans Some are among the most dangerous marine animals.
* Sea wasp, also known as the box jellyfish, of Australia & Southeast Asia
Extreme pain immediately when touched by tentacles
Within minutes, heart failure may occur

47. Types of Cnidarians
Class Anthozoan

48. Types of Cnidarians: Anthozoans
Class Anthozoan
Includes sea anemones & corals
Solitary or colonial polyps
Lack medusa stage
Have more advanced gut – contains several thin partitions called septa that provide extra surface area for digestion of larger prey.

49. Coral Spawning

50. Sea Anemones: Large muscular polyps.
Types of Anthozoans
Sea Anemones: Large muscular polyps.

51. Sea Anemone Importance: Provides Homes
Clownfish are protected from the anemones’ stinging cells by their mucus. They catch food and feed the anemone. Eggs are laid near or under the anemone and tended and protected by the male clownfish.

52. Types of Anthozoans/Corals
Stony Corals:
- Calcium carbonate skeletons that form coral
reefs
- More common in tropics

53. What do Corals Need to Survive?
1. Good Water Quality:
Low turbidity (cloudiness or haziness of water)
Temperature: at least 68° F
2. Sunlight:
Algae that lives inside corals must have sunlight
This is why corals do not live in deep water
3. Zooplankton:
Corals eat zooplankton
4. Water Movement:
Access to food
Flushes sediments off the coral
so they can access sunlight

54. Coral Reef Video Clip

55. Types of Anthozoans/Corals
Gargonians:
- Sea fans
- Secrete a branching skeleton made of proteins.

56. Corals

57. Zooxanthellae Video Clip

58. Mutualism in Anthozoans/Corals
Mutualism: A relationship between two species that benefits both members. The association is necessary to both species.
Corals & Zooxanthellae are mutualistic
Zooxanthellae: an algae
-- Live in the tissues of coral polyps
-- All reef building corals have them
-- Helps corals synthesize (make) calcium carbonate

59. Why Coral Reefs are Important
1. Protect from soil erosion: Waves from the ocean crash onto the shore and over time erode the shoreline.
* Coral reefs that border land act as a buffer for the
harsh waves.
* The reefs cause the waves to slow down or stop
them completely.
* This prevents erosion of the shoreline and potential
property damage.

60. Why Coral Reefs are Important
2. Breeding Grounds & Shelter: Some species that do not even live in the reef may travel to that reef just to breed.
* Coral reefs are very important for replenishing fish
populations that people consume. 60

61. Why Coral Reefs are Important
3. Tourism & Fisheries: They are important for fisheries & tourism businesses. Restaurants, hotels, SCUBA rentals, boat rentals, tour guides, air travel, cruise lines, and many more industries profit from healthy coral reefs. 61

62. Coral Atolls Atolls are coral islands.
The center of the atoll is a shallow lagoon.
Formed when a volcanic island’s middle sank into the
ocean, and left a ring of land
The island bit of the atoll is a narrow ring of land around the lagoon, with coral reefs all around the outside of the island.

63. Ecology
Crown of Thrones Starfish: Well known for its voracious appetite for live hard-corals.
One explanation for local population explosions of these destructive starfish is the collection of this starfish's natural enemy, the Triton Trumpet
Many scuba clubs organize "starfish hunts" in which these starfish are rounded up in an effort to save reefs from destruction.

64. Ecology: Coral Bleaching
The whitening of coral colonies is due to the loss of symbiotic zooxanthellae from the tissues of polyps.
Pollution, temperatures, & disease are being blamed for corals losing their zooxanthelle.

65. Stings from Cnidarians
Symptoms
* Includes corals, jellies, & sea anemones
* Painful raised lesions in lines
* Muscle spasms may develop
* Raised lesions may fill with puss
* May cause nausea, vomiting, dizziness,
headaches, irregular heart rate

66. Stings from Cnidarians
Treatment
* Remove any tentacles (ex: stick)
– Lift off skin, don’t scrape off
-- Don’t use fingers, tentacles can still sting
* Rinse with sea water to wash away
nematocysts left on skin
* Rinse with vinegar – neutralizes nematocysts
-- If there is no vinegar, then urine will work

67. Stings from Cnidarians
Treatment Continued
* Can apply Hydrocortisone is redness persists
* Seek medical attention if muscle spasms
develop
-- Doctor will give you calcium gluconate in IV

68. Death by Cnidarians Stings are usually mild Some stings are fatal
* Box jellyfish -- Mortality rate of about 20% in
1st 3 minutes of a sting
There isn’t an international data base for mortalities by jellyfish stings – exact numbers of deaths are unknown.

69. Look like Cnidarians, but are classified in a different phylum
Phylum Ctenophora
Look like Cnidarians, but are classified in a different phylum

70. Phylum Ctenophora
Includes comb jellies

71. Phylum Ctenophora
Have 8 rows of cilia bands, called comb rows, for locomotion
As they swim, the comb rows diffract light to produce a shimmering, rainbow effect.

72. Phylum Ctenophora
Have colloblasts on tentacles used to capture prey – are adhesive cells that stick to prey
Lack nematocysts
Eat zooplankton only

73. The End