1. Class Anthozoa - characteristics
~ 6000 species
Medusa stage is absent
Polyp is responsible for both sexual and asexual reproduction
Size range from 0.5cm to 1m.
Only cnidarian class that has all three types of cnidae (nematocysts, spirocysts and ptychocysts).

2. Anthozoa – General Anatomy
1. Tentacles
2. Pharynx
3. Siphonoglyph
4. Gastrovascular cavity
5.-7. Septae
8. Gonads
9. Pedal disk

3. Anthozoa – Retractor muscles
Gastrovascular cavity (gut)
Cross section through Gastrovascular cavity
Cross section through pharynx
Pharynx
Retractor muscle fibers

4. Anthozoa – nervous system
Nerve net for epidermis (tentacles)
Nerve net for gastrodermis (body)

5. Anthozoa – Feeding and Digestion
Prey brought in, mixed with mucus, swallowed by pharnx (peristalsis) and transferred to gastrovascular cavity.
Dissolved particles circulated through system by flagella along septae
Longitudinal muscles on septae contract, compressing body, opening mouth and retracting tentacles toward mouth.
Prey captured and subdued by cnidae on the tentacles
Enzymes
Enzymes released from edges of septae to digest.

6. Anthozoa – Gas Exchange and Excretion
Diffusion from tentacles and body cells
Siphonoglyph directs currents to remove waste.

7. Anthozoa - Reproduction
Sexual
Sperm
Planula
Egg
Asexual
Fission
Fragmentation
Budding
Some asexual larval formation (Planula larvae) in corals

8. Class Anthozoa Subclass: Hexacorallia
Subclass: Hexacorallia
Order: Actiniaria (true anemones)
Never colonial
No calcareous skeleton
Some with zoozanthellae
ache.eb.com/eb/image?id=4009&rendTypeId=4

9. Class Anthozoa Subclass: Hexacorallia
upload.wikimedia.org/wikipedia/commons/thumb/4/49/Coral_polyp.jpg/413px-Coral_polyp.jpg
Subclass: Hexacorallia
saltaquarium.about.com/library/graphics/redmushroomtom_400.JPG
Order: Scleractinia (stony corals)
Mostly colonial
Calcareous skeleton
No siphonoglyphs
Half with zoozanthellae

10. Corals Corals flourish in nutrient-poor, clear, tropical waters.
Symbiotic photosynthetic dinoflagellates (zoozanthellae) help corals obtain enough nutrients to grow rapidly.
The corals provide protection and nutrients for the dinoflagellates, which in turn provide the products of photosynthesis to the corals.

11. Corals Corals flourish in nutrient-poor, clear, tropical waters.
Symbiotic photosynthetic dinoflagellates help corals obtain enough nutrients to grow rapidly.
The corals provide protection and nutrients for the dinoflagellates, which in turn provide the products of photosynthesis to the corals.

12.
/t3.pacific.edu/teams/M043406/reef2.jpg
The Great Barrier Reef along the northeastern coast of Australia is 2,000 km long and 150 km wide.

13. Coral reef distribution
Global warming and nutrient runoff are threatening coral reefs throughout the world.

14. Class: Anthozoa Subclass: Hexacorallia
Order: Zoanthidea (stalked anemones)
Order: Actinaria (anemones)
Order: Cerianthara (Tube Anemone)
Brain Coral
Order: Scleractinia (stony corals)
Order: Antipatharia (black coral)

15. Class: Anthozoa Subclass: Octocorallia (octocorals)
8 hollow pinnate tentacles
Single siphonoglyph
Scleroblasts secrete sclerites
Order: Alcyonacea (soft and leather corals)
oceanexplorer.noaa.gov/%E2%80%8Cexplorations/04alaska/media/bamboo_polyp_600.jpg

16. Class: Anthozoa Subclass: Octocorallia
Order: Gorgonacea (red coral, sea plumes, sea fans, sea whips.
Sea Fan
Sea Whip
Order: Stolonifera (organ pipe coral)
Order: Helioporacea (blue coral)
Order: Pennatulacea (sea feathers, sea pens, sea pansies)
Sea Feather
Sea Pansy
Sea Pen

17. Class: Anthozoa Subclass: Ceriantipatharia
Order: Antipatharia (black coral)
Non-retractable tentacles
Thorns present

18. Class: Anthozoa Subclass: Ceriantipatharia
Order: Ceriantheria (tube anemones)
Large solitary polyp
Lives in tube
Long thin tentacles
cache.eb.com/eb/image?id=8947&rendTypeId=4

19. Class Scyphozoa - characteristics
~ 200 species
Medusa stage is present and is the dominant stage
Polyp is a scyphistomae
Size range from 2 cm to 2 m.

20. Scyphozoa – Polyp Anatomy
Tentacles
Periderm (tube)
Septal funnels instead of septae (not shown)

21. Scyphozoa Medusa Anatomy
Tentacles
Oral arms
Gonads
Rhopalium
Chemoreceptor
Mechanoreceptor
Statocyst
Photoreceptor
Manubrium
Tentacles
Oral arms
Gonads
Rhopalium
Chemoreceptor
Mechanoreceptor
Statocyst
Photoreceptor
Manubrium
Radial Canals
Tentacles
Oral arms
Gonads
Rhopalium
Chemoreceptor
Mechanoreceptor
Statocyst
Tentacles
Oral arms
Gonads
Tentacles
Oral arms
Tentacles
Septal funnel with muscle

22. Scyphozoa – nervous system
Nerve ring for bell
Nerve net for manubrium, oral arms, and tentacles.

23. Syphozoa – Feeding, Digestion, Gas Exchange and Excretion
Similar to Anthozoa

24. Scyphozoa - Reproduction
Sexual
Strobila
Ephyra
Planula
Asexual
Budding

25. Class: Scyphozoa Order: Stauromedusae (stalked medusa)
Order: Coronatae (crown jelly)
Order: Rhizostomeae (root mouth jelly)
Order: Semaeostomeae (Flag mouth jelly)

26. Class Cubozoa Box jellies Each polyp produce a single medusa
Box jellies
Each polyp produce a single medusa
Medusa nearly square in X-section
has velarium like hydrozoan medusae
extremely toxic
4 sets of eyes
Light sensor
Image forming eyes
bottom with pupil
pharyngula.org/index/weblog/comments/jellyfish_eyes/

27. Class Hydrozoa - characteristics
~ 3000 species
Mostly colonial medusozoans
Life cycle may include polyps, medusae or both
Unlike other Cnidarians, nematocysts are found only on the epidermis not in the gastrovascular cavity.
Some nematocysts funtional equivalent to Anthozoan spirocysts.
Polyps usually tiny

28. Hydrozoa – Polyp Anatomy
Feeding polyps
Medusae producing polyps (Gonozooids)
Epidermis
Mesoglea
Gastrodermis
Gastrovascular cavity
Note: no septae
Manubrium and mouth
Tentacles
Epidermis
Gastrodermis
Gastrovascular cavity
Pedal disk

29. Hydrozoa Medusa Anatomy
Radial Canal
Gonads
Statocysts and ocelli may be present along edge of bell
Ring canal
Manubrium

30. Hydrozoa Colony Anatomy
Thecate colony
Athecate colony
Theca (part of periderm)

31. Hydrozoa – nervous system
Nerve ring for bell on medusae
Nerve net for manubrium, body, and tentacles.

32. Hydrozoa – Feeding, Digestion, Gas Exchange and Excretion
Similar to Anthozoa

33. Hydrozoa - Reproduction
Sexual
Asexual
Budding

34. Class: Hydrozoa Order: Hydroida Suborder: Anthomedusae (Athecate)
Polyps solitary or colonial
Gonozooids lack exoskeleton (athecate)
Free meduse tall and bell shaped
Gametes form on subumbrella
Tubularia
Hydra sp.
Ectopleura

35. Class: Hydrozoa Order: Hydroida Suborder: Leptomedusae (Thecate)
webs.lander.edu/rsfox/rsfoximages1/hydrozoa4La_x550_x_668x.gif
Obelia sp.
Campanularia sp.
Polyps always colonial
Feeding zooids encased in exoskeleton
Free medusae not usually present
Gamete for on radial canals in subumbrella
Aequorea victoria

36. Class: Hydrozoa Order: Trachylina Botrynema sp. Gonionemus sp.
oceanexplorer.noaa.gov/%E2%80%8Cexplorations/02arctic/logs/mis_sum_pelagic/media/bot_600.jpg
Botrynema sp.
webs.lander.edu/rsfox/rsfoximages1/hydrozoa6L_x550_x_418x.gif
Gonionemus sp.
Gonionemus sp.
Polyp generally absent
Tentacles arise above edge of bell

37. Class: Hydrozoa
Order: Trachylina

38. Class: Hydrozoa Order: Siphonophora Floating or swimming colonies
cache.eb.com/eb/image?id=30731&rendTypeId=4
Physalia
Floating or swimming colonies
Attached modified medusae
In all but one group, the end of the axial polyp forms a pneumatophore for flotation.

39. Class: Hydrozoa - Athecate orders
Order: Siphonophora
Nectophores (attached medusae-like zooids) provide propulsion

40. Class: Hydrozoa – Athecate orders
Portuguese Man-O-War
Order: Siphonophora
Below the nectophores are three types of zooids:
Dactylzooid – grasping and prey-capture
Gonozooid - reproduction
Gastrozooid – digestion

41. Class: Hydrozoa Order: Chondrophora Velella velella
Colonies with gastroozoids, dactylzooids and gonozooids or super organism?
Zooids attached to sail-like float
Velella velella