Though suitable for only the largest aquariums in captivity, the Giant White-Plumed Anemone sure makes an attractive ‘garden’ in the sea!

The Giant White-Plumed Anemone Metridium giganteum or Metridium farcimen truly is a ‘giant’. It has been referred to as the world’s tallest polyp with specimens reaching up to 3 feet tall. This beautiful anemone can be white, reddish-yellow, to brown. Its beautiful lobed oral disk is topped with soft fluffy tentacles and is likened to a feather plume or a powder puff. Thus its various common names such as the Giant Plumose Anemone, Frilled Anemone, Powder Puff Anemone, Sun Anemone, and White-Plumed Anemone.

The Metridium genus is an interesting and much different looking group of anemones. They are cold water dwellers, found in all of the world’s cold water oceans. Their range includes the Atlantic and Pacific Coasts of North America and the coasts of Japan. They occur in intertidal to subtidal zones down to depths of 656 feet (200 m). In shallow areas they can be exposed during low tide, looking much like a droopy wet sock. They use their flower-like tentacles to sting and capture prey, feeding on the small plankton in the water column.

The Giant White-Plumed Anemone, M. giganteum is found from Alaska to southern California, with San Diego being the southernmost limit of its range. They attach to hard surfaces such as rocks, wrecks, pilings and floating docks. They also inhabit the kelp forests and sometimes are seen attached to the backs of kelp crabs and red rock crabs. The Giant Plumose is often confused with its smaller cousin, the Plumose Anemone M. senile. However the Giant Plumose Anemone has more than 100 tentacles on a lobbed oral disc, while the Plumose does not have a lobbed disc, has fewer than the 100 tentacles, and most importantly it only grows up to 4″ (10 cm) .

The Powder Puff Anemone is a hardy, durable, cold water species. These anemones average about 1 1/2 feet tall, but could grow up to 3 feet, so they must be kept in a very large aquarium. If given a cold water reef environment with proper care and feeding, they can live a very long time. They can be centuries old, and in captivity, some were over 100 years old before human error caused their captive demise.

For more about the types of Sea Anemone Species, see:
Sea Anemone – Tube Anemone

Giant White-Plumed Anemone, Metridium giganteum

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This is a great depiction of how the Giant White-Plumed Anemone populates the cold waters of the ocean. It almost looks like a garden of cauliflower, yet under water. The Lingcod is a fish that inhabits the same waters as seems to have no fear! If you want one of these anemones, the first thing on your “to buy” list will be a chiller. They grow 3 feet tall and are carnivores that rely on meaty foods and less on light. And no, they do not host clownfish, but would be happy to show the clown their digestive tract!

Giant White-Plumed Anemone – Quick Aquarium Care
  • Minimum Tank Size: 100 gal (379 L)
  • Aquarist Experience Level: Intermediate
  • Temperament: Semi-aggressive
  • Temperature: 50.0 to 68.0° F (10.0 to 20.0&deg C)
  • Size of organism – inches: 36.0 inches (91.44 cm)
  • Diet Type: Carnivore
  • Suitable for Nano Tank: No

Habitat: Distribution / Background

Sea Anemone Facts: The Giant White-Plumed Anemone or Giant Plumose Anemone Metridium giganteum was described by Fautin, Bucklin and Hand in 1989. The Metridium genus is a member of the Metridiidae family, and there are 9 species in this genus. Other common names this anemone is known by are Frilled Anemone, Powder Puff Anemone, Sun Anemone, White-Plumed Anemone, and White Plume Anemone. The Metridium giganteum is not on the IUCN Red List for endangered species.

The Metridium genus was described by Blainville in 1824. Besides the Giant White-Plumed Anemone Metridium giganteum, a few of these species are M. dianthus, M. exilis, M. farcimen, M. fimbriatum, M. marginatum, M. parvulum, M. senile, and M. sinensis.

The Sun Anemone is often confused with its smaller cousin, the Plumose Anemone M. senile. However the Giant Plumose has more than 100 tentacles on an lobbed oral disc, while the Plumose does not have a lobbed disc, has fewer than the 100 tentacles, and most importantly it only grows up to 4″ (10 cm) .

Where are Sea Anemones Found: The Metridium genus is found in all of the world’s cold water oceans such as the Atlantic and Pacific Coasts of North America and coasts of Japan. The M. giganteum is found from Alaska to the Catalina Island along the California coast, and is also located in Puget Sound, the Strait of Georgia, and the San Juan Islands.

Sea Anemone Habitat: They occur in intertidal to subtidal zones down to depths of 656 feet (200 m). They attach to hard surfaces such as rocks, wrecks, pilings and floating docks. They also inhabit the giant kelp forests and are sometimes seen attached to the backs of kelp crabs and red rock crabs. In shallow areas they can be exposed during low tide, looking much like a droopy wet sock.

Metridium anemones use their flower-like tentacles to sting and capture prey. They feed on small plankton in the water column. Certain nudibranchs species and common sea stars including the Pisaster genus, prey on these anemones.

  • Scientific Name: Metridium giganteum
  • IUCN Red List: NE – Not Evaluated or not listed

Description

Appearance of a Sea Anemone: The Giant White-Plumed Anemone or Giant Plumose Anemone usually comes in white, although brown and brick red-orange varieties have been found. The brown ones are usually found in California waters and the other colors are located in the Pacific Northwest areas.

The pedal column has a sticky foot that the anemone can use to adhere to surfaces. The pedal column also has little “threads” that can shoot nematocysts in defense if it so desires. Supposedly, human skin is not affected, but the eyes and tongue will suffer, so licking them would be a bad idea!

Tentacles are long and skinny and can number to 100 in larger animals. They appear soft and fluffy, looking like a feather plume or a powder puff. The oral disc is lobed only on the edges and it is smoother in the center area. The mouth should be closed and tight, and will open when hungry, having an oval look, yet a gaping mouth is a warning signal. The M. giganteum takes food in, and expels waste through this same opening.

Sea Anemones Life Cycles: These anemones can reach up to 3 feet tall (1 m) but are usually 1.6′ (50 cm) with the top being almost 10″ (25 cm) in diameter. They can be centuries old, and in captivity, some were over 100 years old before human error caused their captive demise.

  • Size of organism – inches: 36.0 inches (91.44 cm)
  • Lifespan: – They can live for centuries – the oldest in captivity lived over 100 years.

Difficulty of Care

Sea Anemone Care: This anemone is rarely available for sale. If you are able to acquire them, the Giant White-Plumed Anemone is moderate to difficult to care for because they must be in cold water and must be in a large enough aquarium to satisfy their ultimate size. A saltwater aquarium should be at least 6 months old and stable before adding a new M. giganteum.

When choosing your Frilled Anemone, make sure the color is good, their mouth is not gaping open, and their foot and tentacles are sticky to the touch. Also, they should be attached to something and make sure there is no damage to the foot area, often a result of pulling the anemone off its surface.

To take a M. giganteum anemone from another aquarium, use a very thin blunt item like a credit card to get under the foot. Slowly nudging it away will get the anemone off the glass. If it’s attached to a rock, ideally you can simply purchase the rock as well. If you cannot purchase the rock then directing water at it or wiggling the rock gently upside down under water while tickling the foot can work.

  • Aquarium Hardiness: Moderately Difficult
  • Aquarist Experience Level: Intermediate

Foods and Feeding

What Do Sea Anemones Eat: The Giant Plumose Anemone is a carnivore. In nature they use their flower-like tentacles to sting and capture prey, feeding on the small plankton in the water column. Feeding in captivity should be similar to their habitat’s provisions. Feed several forms of plankton, including cyclopeeze and similar sized foods along with finely minced crustacean flesh. Feed 2 times a week or more depending on the size of the animal.

  • Diet Type: Carnivore
  • Meaty Food: All of Diet – Feed several forms of plankton, including cyclopeeze and similar sized foods along with finely minced crustacean flesh.
  • Feeding Frequency: Weekly – Feed twice a week minimum.

Aquarium Care

Water changes of 10% bi-monthly or 20% a month are typical. Monitor your water quality for your particular situation and adjust your water changes accordingly. One average sized young anemone 2″ to 4″ is equal to 2 or 3 fish as far as waste production is concerned. Purigen and Poly-fiber are great products to help in maintaining water quality. Purigen is a synthetic polymer that removes soluble and insoluble impurities from water at an exceptionally high rate and capacity, helping to control ammonia, nitrites and nitrates. Additions of Iodine and and trace elements are suggested.

  • Water Changes: Bi-weekly
  • Iodine Levels: – Additions of Iodine and and trace elements are suggested.

Aquarium Setup

The typical reef environment is what is needed for your Giant White-Plumed Anemone; i.e. live rock in a reef environment for cold water. They need live rock or some other solid material they can attach to. This is a cold water anemone and a chiller is needed to provide the proper environment, unless you live where it is very cold year round. Be sure to have all of your pumps covered, most good quality pumps have guards on them and are worth the investment.

  • Minimum Tank Size: 100 gal (379 L)
  • Suitable for Nano Tank: No
  • Live Rock Requirement: Typical Amount
  • Substrate Type: Any
  • Lighting Needs: Moderate – normal lighting
  • Temperature: 50.0 to 68.0° F (10.0 to 20.0&deg C)
  • Specific gravity: 1.023-1.025 SG
  • Water Movement: Moderate – Low to Moderate.
  • Water Region: Bottom

Social Behaviors

The Metridium genus are semi-aggressive because they can be mobile and can sting stationary corals. It has often been suggested to not put anemones in a reef environment because corals cannot move away from the stinging tentacles. Once you have your anemone situated and it has not moved for several months, it might be safe to add other corals. This would be a “proceed at your own risk”. Keep this in mind when stocking sessile inverts.

After splitting, anemones will tolerate their own “clones” and sometimes their own species. If housing a different genus, they need to be at least 2-3 feet away from each other. Otherwise there will be “chemical” warfare with other species of anemones. This will usually cause one type of anemone to not eat, shrink and eventually die.

  • Venomous: Yes
  • Temperament: Semi-aggressive
  • Compatible with:
    • Same species – conspecifics: Sometimes
    • Anemones: Monitor
    • Mushroom Anemones – Corallimorphs: Monitor
    • Leather Corals: Monitor
    • Starfish: Monitor
    • Nudibranch, Sea Slugs: Monitor
    • Stony Corals: May be aggressive
    • Soft Corals: May be aggressive

Sex: Sexual differences

No sexual difference in appearance is known.

Breeding / Reproduction

There is no information as of yet on propagation of the M. giganteum. The Metridium genus reproduces sexually. They do release sperm and eggs into the water column, yet this will seldom be seen in captivity. They reproduce in this manner releasing male and female sex glands into the water where fertilization takes place. This results in the production of ciliated planula larvae. This planula will eventually fall to the sea floor, develop a pedal disk, and then begin to grow into a new anemone.

This genus can also reproduce asexually by laceration and fission. Laceration is when they move over a surface and leave chunks of themselves behind. These pieces eventually form into a new anemone. Fission is when they split in half forming 2 smaller versions of themselves.

  • Ease of Breeding: Unknown

Ailments / Diseases

Problems for the Giant White-Plumed Anemone are pretty minimal unless your lighting, water movement, feeding and water quality are low. Then your anemone will detach to look for “better conditions.” This usually results in an unpleasant experience with a water pump.

Sea Anemone Predators: These anemones do have predators in the wild. Certain nudibranchs species and common sea stars including the Pisaster genus, prey on these anemones.

Availability

Buy A Sea Anemone: The Giant Plumose Anemone, as well as other species in the Metridium genus are very rarely for sale, making them generally unavailable to aquarists. Collection in some areas may be restricted. So before collecting them, be sure to check with local authorities in the area you are in to find out if they are protected there.

References


Featured Image Credit: Reimar, Shutterstock