1. Class Scyphozoa “true” jellyfish medusa & polyp body forms
thick mesoglea

2. Class Scyphozoa- life cycle
sperm
egg
ephyra
Adult medusa
strobila
scyphistoma
larva

3. Jellyfish Diversity
Jellyfish are a major ecological significance of the plankton. Found in all oceans and range from the sea surface to the abyss. There are about 200 species world wide.

4. Jellyfish Diversity

5. Semaeostomae Jellyfish-- the typical jellyfish: corner of mouth drawn out into four broad gelatinous frilly lobes.
Aurelia sp.

6. Cyanea capillata the Giant Jellyfish or Lion's Mane Jellyfish can grow to be one of the largest of all jellyfishes. Its disc-shaped bell can be over 1 meter across and its trailing tentacles can reach more than 10 meters in length.

7. Primitive jellyfish: Stauromedusae

8. Jellyfish Diversity
Primitive jellyfish: Stauromedusae; small sessile individuals that develop directly from benthic planula larvae.
Can change locations, but normally attached with stalk and adhesive pad to solid objects like kelp and rocks.

9. Rizostomae jellyfish: lack a central mouth, instead they have many suctorial “mouths”

11. Cassiopea: a small tropical jellyfish is unusual among jellyfish.
It lies on the bottom in shallow waters, with its mouths and tentacles oriented upwards. Its mouth is much reduced, and is not much used.
Instead, the jellyfish gets most of the nutrition it needs from symbiotic dinoflagellates (protists) which live inside its body tissues.

12. Rhizostoma octopus

13. Class Cubozoa: Sea wasps and box jellyfish About 3 dozen species almost all are tropical.
medusa & polyp body forms
thick mesoglea

15. Unfrilled bell margin drawn inward to form a velum-like structure.

16. velarial canals
The velarium is at least partly responsible for the great speeds with which cubozoans are able to swim.
Velarial canals are extensions of the gut and they are important in telling one species of cubozoan from another.

17. Manubrium: a tubular extension where the mouth is.

18. Cubozoan Sensory Structures
Sensory structures called rhopalia.

19. Cubozoan Sensory Structures
cubozoans have eyes.
The larger regions actually contain lenses, corneas, and retinas.

20. Nematocysts are concentrated in rings on the tentacles of cubozoans.

24. Predominantly two species responsible
The Box Jelly Chironex fleckeri
Irukandji Carukia barnesi

25. The Box Jelly Chironex fleckeri

26. The Box Jelly Chironex fleckeri

27. Box Jelly Chironex fleckeri
Box jellies or sea wasps are thought to be responsible for about deaths over the past 50 years in Australia.
The tentacles can be up to 10 feet long.
In Australia twice as many people die annually from box jellies as from sharks.
The toxin of most cubomedusan jellies is more potent than cobra venom.

28. Irukandji Carukia barnesi
Stings have been recorded from Australia, and a similar syndrome has been described elsewhere in the Pacific.
Every summer, more than sixty people are hospitalized with this potentially fatal syndrome.

29. Irukandji Carukia barnesi
The initial sting of the jellyfish is usually not very painful.
But about 30 minutes after being stung, the person starts to have a severe backache or headache and shooting pains in their muscles, chest and abdomen.
They may also feel nauseous, anxious, restless and vomit. In rare cases, the victim suffers pulmonary aedema (fluid on the lungs) which could be fatal if not treated.

30. Cubozoan Life Cycle
Some species of cubozoans appear to pair up, male with female, in order to mate.
The male puts his tentacles into the bell of the female and appears to pass packets of sperm. At least one species has been observed in large mating aggregations.

31. Cubozoan Life Cycle
Fertilization takes place inside the females. In some species the fertilized eggs are released into the water column where they develop into planulae, while in others development into planulae occurs inside the female.

32. Cubozoan Life Cycle
The polyps can move around, and they frequently bud off additional polyps.

33. Cubozoan Life Cycle
During metamorphosis, the polyp tentacles are resorbed and four new tentacles and four rhopalia are formed. With a couple of contractions, the entire individual becomes detached and swims away as a juvenile medusa.

34. Class Anthozoa
polyp body form ONLY
all marine

35. Class Anthozoa some are colonial
 colonies are formed of individual zooids
some are solitary

36. Class Anthozoa- life cycle
Sexual reproduction
sperm
egg
larva

37. Class Anthozoa- life cycle
asexual reproduction
fission
pedal laceration
fission