1. Spineless As a Jellyfish

2. What makes something a Jellyfish?
Take a second:
On a blank sheet of paper write down all of the characteristics that identify a jellyfish.
When you think of a jellyfish—what do you think of? Describe the picture in your mind
Now: Draw the jellyfish you just described.

3. Jellyfish History
Jellyfish have been around for over 650 million years
There are more than 2000 known species
Can be found everywhere from the surface of the water to the depths of the ocean

4. What is a Jellyfish? Where do they fit in?
A jellyfish is not a fish at all, it is an invertebrate in the phylum Cnidaria
Cnidarians are a group of invertebrates that have stinging tentacles
This includes corals, anemones, and JELLYFISH

5. Cnidarian Characteristics
All Cnidarians share the following characteristics:
Invertebrates (no backbone)
Radial symmetry (tentacles arranged around a central mouth)
Tentacles
Only 2 cell layers
Saclike digestive tract (in and out the same way)
Simple nervous system (nerve net)

6. Bounce on the Tops The top of the jellyfish is called the medusa
It is made of 2 cell layers
Epidermis (outside) and gastrodermis (inside)
In between the layers is a jelly-like material called the mesoglea
A jellyfish is 90% water

7. Jellyfish Movement
Jellyfish float on the water because the mesoglea is less dense than the ocean
Move by contracting the medusa in a rhythmic motion
Very weak swimmers and will not swim after humans or prey

8. Living and Breathing
Oxygen will diffuse directly INTO the cell membrane from the water
Carbon dioxide and wastes will diffuse OUT OF the cell membrane into the water

9. Feed Me: Tentacles have 2 main functions: Tentacles:
Gather food and
Bring the food to the mouth and digest it in the cavity
CNIDOBLASTS are the stinging cells IN the tentacles:
Little barbs in the cells called NEMATOCYSTS poke into prey and disable them
They can only be used once and then need to be replaced

10. Nematocyst
The barbs inside the stinging cells (cnidoblasts) that are inside tentacles and contain toxins
>Now watch it in slow motion!

11. Predators and Prey Predators (who eats jellyfish?):
Tuna
Sharks
Turtles
Prey (what do jellyfish eat?):
microscopic plankton, fish larvae, other jellyfish

12. Making More Jellyfish
The four-leaf clover on top of the jellyfish are the sex organs
Sperm cells swim out of the mouth of the male and into the mouth of the female
Egg cells are fertilized in the female ovary

13. Jellyfish Life Cycle Larva are called planula
They attach to a substrate and develop into a POLYP
The POLYP will mature and develop into a MEDUSA which is a free floating organism

15. Human Uses of Jellyfish
Food: 12 different species of jellyfish are used in food in southeast Asia
Bioluminescence: Scientists found a protein for bioluminescence in jellyfish and recreated it to help detect specific genes in cells

16. Jellyfish Blooms
A jellyfish happens when ocean currents and other environmental events cause there to be groupings of thousands of jellyfish!
Blooms can have a bad effect on people as they result in:
More jellyfish stings
Decline in tourism on coasts
Decline in commercial fish supplies due to jellyfish feeding
Clogging engines of boats, power plants and desalination plants

17. Jellyfish Stings
Many jellyfish stings are not deadly and only cause irritation
Some jellyfish venom can cause anaphylaxis (allergic reaction where you can’t breath)—which may result in death
Box jellyfish stings can be deadly

18. Treatment of Jellyfish Stings
Primary Goal of treating jellyfish stings:
Prevent injury to rescuers
How to treat Jellyfish stings:
Inactivate nematocysts—using vinegar or salt water (do not use alcohol, ammonia, or urine)
Remove tentacles attached to the patient - shaving the area with a safety razor or credit card also removes nematocysts

19. Largest Jellyfish Lion’s Mane Jellyfish
Medusa can be up to 7 feet in diameter
Tentacles can reach 120 feet

20. Smallest Jellyfish
Irukandji
Only 1.5 inches across
Almost invisible

21. Most Toxic Jellyfish Box Jellyfish
Most deadly venom in the animal kingdom (caused 5568 recorded deaths since 1954)
Found in the warm waters of Australia and Indo-Pacific

22. Amnemonemomne
Sea Anemones

23. Sea Anemone Characteristics
Classified in the class Anthozoa (which means “flower animal”)
Tentacles
Radial Symmetry
Nerve net
Sessile (stationary) lifestyle

24. Feeding in the Sea Anemone
Tiny organisms and small fish swim into the tentacles and are paralyzed
Bring food to mouth
Food is digested in the digestive sac
Undigested food and wastes are eliminated through the mouth

25. Sea Anemone Life Cycle Sea anemones do not reach a medusa stage
They live as a polyp, attached to a substrate
Reproduction:
Asexually - fission, regeneration
Sexually - male and female sex cells combine

26. Symbiosis
Symbiosis: a mutually beneficial relationship between different species
Ex: sea anemones and clownfish
Clownfish keep the anemone from being bitten by other fish
Sea anemones protect the clownfish from predators

27. Predators and Prey Predators: grey sea slug, tompot blenny
Prey: small fish, shrimp, sea stars

28. Sea Anemone Habitat
Sea anemones are mostly found in rocky coastal areas
When the tides go out, they can be found in tide pools

29. Sea Anemones vs. Jellyfish
Both
Jellyfish
Sessile
Symbiotic Relationships
End at polyp stage
Basic cnidarian characteristics
Stinging Tentacles
Radial symmetry
Sac-like digestive tract
2 Cell layers
Nerve net
Medusa stage
Free swimming