1. Sea Anemones

2. Beaded Sea Anemone Zebra Anemone Red Anemones on Reef
Image 1 “Colonial anemone zebra”.online image.07/03/05.wikipedia commons. <
Image 2 Jon Radoff “beaded sea anemone with shrimp”. Online image wikipedia commons <
Image 3 “ocean reef”. Online image. 3/12/07. wikipedia commons. <
Red Anemones on Reef

3. Classification/Identification
Anemones are cnidarians
Members of the class Anthozoa (meaning “flower animal”)
Stinging tentacles
Radial symmetry
Nerve net
sessile
Image- zoom schoo l“sea anemone internal anatomy”. online image.2009 <
They are part of the phylum Coelenterata which includes corals, jellyfish, sea anemones and hydroids.There are many different types of anemones but can make some generalizations about them. As seen in image have a columnar body shape, with single body opening that is surrounded by poisonous tentacles. Usually are between 1 to 4 inches in length but some have actually been recorded to grow up to 6 feet.
They have very few predators but are eaten by the grey sea slug and the tompot blenny. They are very long living organisms, having life spans between 60 and 80 years in the wild. They do not age and therefore have the potential to live indefinitely.
What makes them different from jellyfish is that they live as polyps in their adulthood, attached to a substrate by a muscular foot rather than living as a free floating being like jelly fish.
Greene, Thomas F., Marine Science:Marine Biology and Oceanograpy.Amsco School Publications,2004

4. Habitat Live in salt water environment
Found in coastal/shallow waters (coral reefs) and in deep ocean waters as well
Temperate and tropical areas worldwide
Do not change location from where they first planted themselves unless sense that their environment is unstable
Often found in crevices, under rocks, and on coral. Attach themselves with a muscular foot to a stable place but sometimes are found attached to hermit crab shells, forming a mutualistic relationship. Aren’t autotrophs so don’t necessarily have to be in the sunlight.
Jenny Stevenson. “Sea Anemone Habitat”. Sea Anemones. October <

5. Nervous system Very simple nervous and muscular system
Decentralized nervous system that controls functions in order to maintain homeostaysis
As well biochemical and physical responses to stimuli
For example, if you were to touch an anemone the entire animal contracts, withdrawing all of its tentacles into the polyp
“Sea Anemones." Wikipedia, The Free Encyclopedia. March 15, Wikimedia Foundation. <

6. Movement Usually have limited movement-as they are sessile
However can move if feel threatened in environment by muscular movements and plant themselves in a new area with substrate (muscular foot)
Greene, Thomas F., Marine Science:Marine Biology and Oceanograpy.Amsco School Publications,2004

7. Feeding Uses nematocysts on tentacles to paralyze prey
Tiny fish swim into tentacles
After capturing food , brings it to its mouth and food is digested inside the digestive sac by enzymes
Digestion is mostly extracellular
Two –way digestive tract…Undigested food particles and wastes are eliminated through the mouth as well
The stomach of an anemone is simply a gastrovascular cavity. It is simple in nature because the hole into it functions as a mouth and way for material to be excreted from the anemone. They are carnivores so their main diet includes fish, mussels, zooplankton, and worms.
Greene, Thomas F., Marine Science:Marine Biology and Oceanograpy.Amsco School Publications,2004

8. nematocysts
Each one contains a small vesicle filled with toxins called actinoporins
When the hair is touched mechanically triggers a cell explosion that injects poison into the prey
This is why anemones have a sticky feeling
Image “nematocysts”.online image <
“Sea Anemones." Wikipedia, The Free Encyclopedia. March 15, Wikimedia Foundation. <

9. Life cycle Dominant structure is polyp
Are sessile so live attached to a substrate for life
Reproduce sexually and asexually
Sexually-Produce embryos that develop into planula larvae which settle and develop into adult polyps
Asexually-regeneration from pieces of the polyp’s base
Sexual Reproduction
Depending on the species, some will have the capability of producing both sperm and eggs, while others are distinctly female or male. Eggs and Sperm are released into the ocean through the mouth. If an egg is fertilized it forms an embryo that eventually will settle to the bottom and develop into an adult sea anemone.
Asexual Reproduction
This happens by budding which is when part of an anemone grows off of another anemone to eventually break off and live as a separate entity. Also can occur by pedal larceration which is when a small piece breaks off of the basal disc and grows into an adult anemone.
Jenny Stevenson. “Sea Anemone Life Cycle”. Sea Anemones. October <

10. Symbiosis
Symbiosis is a mutually beneficial relationship between two different species
Usually involves a mutual protection and or living habitat for each species
Anemone live in harmony with clownfish, hermit crabs, and algae
You can see this demonstrated in Finding Nemo!
Clownfish- Clownfish are able to gain protection from the sea anemones, and are immune to the sting of the tentacles because they have a mucus coating. They hide and live in the tentacles. Simultaneously the clownfish give protection to the anemones because they prevent other creatures from biting at the tentacles of the anemone. They also help by cleaning the tentacles.
Hermit Crabs- The hermit crabs can gain protection from the anemone because it is a sort of camouflage on their shells. In turn they protect the anemone from its predators.
Green Algae-The anemones provide the algae with a safe habitat while the algae provides the anemone with oxygen and sugar-the products of its photsynthesis
Greene, Thomas F., Marine Science:Marine Biology and Oceanograpy.Amsco School Publications,2004

11. Image mila Zinkova. “Anemone fish fiji”. Online image
Image mila Zinkova. “Anemone fish fiji”. Online image. Wikipedia commons. <

12. Exploitation Part of global trade in marine ornamentals
200 to 300 million dollar industry
Usually collected from the wild as juveniles or adults
Aquarium fishing activities significantly impact the populations of anemones
Are able to live in captivity but not as long as they can in the wild
“Sea Anemones." Wikipedia, The Free Encyclopedia. March 15, Wikimedia Foundation. <