Giant green anemone, ocean acidification
Platyhelminthes intro

Whose been surfing
Tofino?
Whose seen these?
http://www.flickr.com/photos/chayshots/235067851/

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Clue

Anthozoa
• true corals, anemones, sea pens, sea fans
• Lack a medusa phase.
Anthozoa (means “Flower like”)
Remember your mnemonic
Hydrozoa
Scyphozoa
• Alternate between
• Small in size, polyp and medusa usually mistaken for stage algae
• Medusa stage usually
• Most alternate life larger and more stages between developed than the medusa and a polyp polyp
• Often form colonies
• The familiar jellyfish

• Largest green anemone in the world
• Giant green anemones that live in sunlight are a vivid green
• Specimens in caves are paler, nearly white.
• Why?
• Zooxanthellae

• The Giant Green anemone can move on its pedal.
Reading
• Discussion
• Fill out examination worksheets

• Range: Low to mid intertidal zones of the Pacific Ocean, ranging continuously from Unalaska to Point Conception. It also occurs in areas of cold upwelling, possibly as far south as Panama.
• Habitat:
• Exposed coastlines, bays and harbors, on seawalls, rocks, tidepools, and pilings.
• From above low tide line, to about 50 ft. (15 m) depth.
• Each Giant green anemone is solitary, but is often in tentacle-tip contact with others in favorable tidepools and conditions, and can be found in densities of up to 14 per m².
• Although their habitat can become crowded, they do not display aggressive behaviors, seen in their smaller relative, A. elegan-tissima.
• A. xanthogrammica is restricted to the lowest tide zones, where surf and currents continually provide a fresh supply of water, and cannot survive where there is industrial pollution, sewage, or sludgy water.

Also occurs here in cold water upwelling zones.

Capture prey with stinging nematocysts in their tentacles.
Desiccation?????
Cause no harm to humans. Drying up
Omnivore,
Photosynthetic,
Scavenger, Sessile suspension feeder
To prevent from desiccation, giant green anemones will retract their tentacles and close, during low tides.
Video: http://www.montereybaya
quarium.org/videos/Video.
aspx?enc=0ZZ+8rD1FkZF
Mg4UwjaBnQ==

• Crashing waves bring foods into the tentacles of the anemone

Predator-Prey relationships
Predators Prey
• Nudibranch’s and Snails feed on the tentacles, and column .
• Sea slugs eat anemones, including the stinging cells, but they don’t get stung.
The slugs use the anemones stingers for defense against predators, by moving them onto their own bodies.
• Prey: mussels, sea urchins, small fish, and crabs.

Green Anemone as these clownfish do with this anemone.
• The larvae preferentially settle in mussel beds, in anticipation of this future food source.
• Later, they migrate downward to take up their characteristic position, in the pools and channels below the musssel bed, where they wait for food to drop down from above.
• Prey are paralyzed and captured after coming into contact with the anemones stinging tentacles. Once the prey has been paralyzed, A. xanthogrammi-ca pulls these animals into its mouth, located in the center of its crown.
• When digestion is finished, it excretes the waste through the same opening.
• The epidermis and tissues lining the gut of A. xanthogrammica contain living photosynthetic algae zooxanthellae. These symbiotic protists can produce organic nutrients through photosynthesis that may also contribute to the nutritional needs of the anemone.
• Mussels and snails are washed into anemones waiting tentacles, as the wave’s crash against the shore. The anemone eats the animals, then spits out the clean shells. Empty snail shells, may become homes for hermit crabs.
• The hermit crab Pagarus samu-elis often walks up and down the column of the anemone, even walking through and stroking the tentacles and probing the mouth opening, all without being stung. It is possible that the hermit crab becomes so coated with mucus from the anemone that the anemone responds as if the crab were its own tissue.
• Hermit crabs which are not previously associated with the anemone may be eaten, or simply taken into the gastro vascular cavity and then later released.

• Giant green anemones release sperm and brownish eggs in late spring and summer, producing pelagic, planktotrophic larvae.
(Open ocean, plankton eating, larvae)
What are the two major reproductive strategies of Cnidarians????
Sexual and Asexual. The Giant green anemone does not reproduce asexually.
• Larval development has not been closely followed, but the larvae swim or float freely for some time, and become widely dispersed.

• Anthopleura
xanthogrammica has been the source of several medical studies.
• “Contained within its tissues is a cardiotonic agent that has been associated with favorable stimulatory effects when introduced to the vertebrate heart.”

• 2 species of anemone M. farcimen and A. xanthogrammica
• M. farcimen lives in deeper waters not exposed to strong wave action.
• A. xanthogrammica are exposed to strong wave action.
• What adaptations do you notice in the Giant Green
Anemone to the strong wave action?

Different body types will exist among individuals within the species A. xanthogrammica
• Which part of this shore will experience greater wave action?
• What differences do you notice in body type?
• Smaller diameter and smaller stem in higher wave areas

• worksheet