Christmas Anemone

Painted Urticina, Northern Red Anemone

Christmas Anemone, Urticina crassicornis, , Painted Urticina, Northern Red AnemoneUrticina crassicornisPhoto Wiki Commons, courtesy Jack C. McGee.
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The Christmas Anemone is an easily identified Urticina Anemone, with its smooth column and opaque, often colorful tentacles!

The Christmas Anemone Urticina crassicornis is a colorful and common cold water anemone from the North Pacific. If you keep a coldwater system, the Christmas Anemone is another anemone variety to add to your display. They are a moderate sized anemone with the column being about 3" (7.6 cm) in diameter, with across the crown reaching about 10" (25 cm). As long as their requirements are met, they are easy to care for. But it is a good idea to invest in a chiller before you obtain one of these guys.

Of the Urticina anemones, a couple species have very festive colors and at first glance they look very similar to one another. The Christmas Anemone Urticina crassicornis is one of these. Its similar looking relatives include the Painted Anemone Urticina grebelnyi and the Dahlia Anemone Urticina felina. Common names you'll see for these fancy anemones include the Mottled Anemone, Painted Urticina, Northern Red Anemone, Painted Tealia, Red and Green Anemone, Northern Red Anemone, Dahlia anemone, and Thick-Petaled Rose Anemone.

Although these common names are often used interchangeably, there is basically one generally accepted common name for each species. And though these Urticina anemones can look quite similar to each other, each one has its own unique characteristic to identify it by.

The unique characteristic of the Christmas Anemone is that it always has a smooth column. It ranges from pale orange to reddish-brown often contrasted with stripes or irregular patches. The oral disc is a pale white or yellow, usually sharing the same solid color in the tentacles. The mouth is reddish and there are red radial bands outlining the base of each tentacle.

When caring for this Anemone, using similar husbandry for other cold water anemones is suggested. Like all anemones, these Painted Anemones use their venomous cells or nematocysts found in their tentacles to sting and deflect any possible threats or attacks. But they mostly utilize them for stunning and capturing prey. Some predators of this anemone can be certain nudibranchs, sea stars, and snails.

For more facts about Urticina Sea Anemones, see:
Nettle Anemones

Geographic Distribution
Urticina crassicornis
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Christmas or Northern Sea Anemone, Urticina crassicornis

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Christmas Anemone feeding

The Christmas or Northern Sea Anemone has a few name that reflect the temperature of the waters they are found in.... cold! They are similar in appearance and stickiness of most "rock anemones" and are easy to feed. The challenge is keeping your tank between 50.0 to 68.0° F (10.0 to 20.0° C), provide enough light and good water movement. They are great in a cold water nano tank and are easy to feed!

Christmas Anemone - Quick Aquarium Care
  • Minimum Tank Size: 10 gal (38 L)
  • Aquarist Experience Level: Intermediate
  • Temperament: Semi-aggressive
  • Temperature: 50.0 to 68.0° F (10.0 to 20.0° C)
  • Diet Type: Carnivore
  • Suitable for Nano Tank: Yes

Habitat: Distribution / Background

Sea Anemone Facts: The Christmas Anemone or Northern Red Anemone Urticina crassicornis was described by O. F. Mueller in 1776. The Urticina genus belongs to the Actiniidae family, and this genus contains 6 species. It was formerly called the Tealia crassicornis. Some other common names they are known by are Painted Anemone, Northern Red Anemone, and Painted Urticina. This anemone is not on the IUCN Red List for endangered species.

Where are Sea Anemones Found: The U. crassicornis is widely distributed and common in the North Pacific and other northern seas. .

Sea Anemone Habitat: These anemones are found in intertidal colder waters down to about 98 feet (30 m). They inhabit vertical rock walls that are shaded, or sand and rock covered shore lines as well as tide pools. They are found solitary or in small groupings. Similar to other cold water tidal anemones, they retract their tentacles and close up if the water is sparse during low tides.

They eat prey similar to what other Urticina anemones eat such as sea urchins, small fish, crabs, mussels, gastropods, chitons, barnacles, and they may feed on stranded jellyfish. They use their venomous cells or nematocysts found in their tentacles to sting and deflect any possible threats or attacks but mostly utilize them for stunning and capturing prey. Some predators can be certain nudibranchs, sea stars and snails. The Candy Stripe Shrimp Lebbeus grandimanus is immune to its sting and lives in a commensal relationship with it.

  • Scientific Name: Urticina crassicornis
  • IUCN Red List: NE - Not Evaluated or not listed


Appearance of a Sea Anemone: The Christmas Anemone has a very smooth column that is not sticky like other Urticina. This is one characteristic which sets them apart from other species. The color of the column ranges from pale orange to reddish-brown and can have contrasting colors of stripes or irregular patches.

It does have a "foot" at the bottom of the pedal column which it uses to adhere to various surfaces. They also use this foot to move around if conditions are not ideal. They can also move by inflating themselves, detaching from the surface, and then rolling along with any current. They will move to avoid predators like starfish, but in the aquarium it is primarily if they are unhappy with the water conditions or the food.

The tentacles are well spaced and are in 5 or more rows. The top row surrounds a mouth that is reddish in color. The oral disk is more pale than the column. It is white or pale yellow with red radial bands that outline the base of each tentacle. The tentacles are usually the same color as the oral disk, and are solid with no markings. 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 U. crassicornis takes food in and expels waste through this same opening.

Sea Anemones Life Cycles: Christmas Anemones can grow up to 3" (7.6 cm) in diameter and can reach as tall as 5" (12.7 cm) or more. They can live from 60 to 80 years.

  • Size of organism - inches: - They can grow up to 3" in diameter with the crown reaching 10", and as tall as 5" in height.
  • Lifespan: 80 years - They can live 60-80 years.

Difficulty of Care

Sea Anemone Care: The Painted Anemone is easy to care for if you have appropriate lighting and cold water. As with most anemones, the tank should be at least 1 year old and stable before adding your new Painted Urticina.

When selecting a U. crassicornis, 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 Christmas Anemone from another aquarium, use a thin blunt item like a credit card, gently wiggle it under the foot, slowly nudging it away from the glass. If it's attached to a rock, ideally you can simply purchase the rock as well. On a rock, it would be very wise to purchase the rock, because these guys can stick hard and would probably be damaged if removed. 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 hardy
  • Aquarist Experience Level: Intermediate

Foods and Feeding

What Do Sea Anemones Eat: The Northern Red Anemone is a carnivore. Feed your U. crassicornis chopped silversides, shrimp, krill, and mussels, fresh chopped fish (from your grocery store), as well as frozen carnivore preparations. Feed once a week or twice a month, since cold water anemones have much slower metabolisms.

  • Diet Type: Carnivore
  • Meaty Food: All of Diet - They can be fed chopped silversides, shrimp, krill, and mussels, fresh chopped fish (from your grocery store), as well as frozen carnivore preparations.
  • Feeding Frequency: Seldom - Feed them once a week to twice a month.

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. An average sized Christmas Anemone is equal to about one 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 Christmas Anemone, but it must be a cold water reef. It is a good idea to invest in a chiller before you obtain one of these guys. They need live rock or some other solid material they can attach to. Provide some rock crevices as well as rocky overhangs. 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: 10 gal (38 L)
  • Suitable for Nano Tank: Yes
  • 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° C)
  • Specific gravity: 1.023-1.025 SG
  • Water Movement: Moderate
  • Water Region: Bottom

Social Behaviors

All anemones are semi-aggressive because they can be mobile, although most of the cold water anemones stay still if their needs are met. 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. Just keep in mind these anemones will sting everything they can reach, such as corals and other invertebrates. Anemones will move if your lighting is not good, or the water quality is not to their liking.

After splitting, anemones will tolerate their own "clones" and sometimes their own species. All anemones in the tank need to have their own space, otherwise there can be a "chemical" warfare between species. This will usually cause one to not eat, shrink and eventually die. Having excellent filtration and a large tank will usually allow 2 anemones at opposite ends to thrive. You can also build a natural blockade to help prevent them from wandering into each others "space".

  • Venomous: Yes
  • Temperament: Semi-aggressive
  • Compatible with:
    • Same species - conspecifics: Sometimes
    • Anemones: Monitor
    • Mushroom Anemones - Corallimorphs: Monitor
    • Leather Corals: Monitor
    • Zoanthids - Button Polyps, Sea Mats: Monitor
    • Sponges, Tunicates: Monitor
    • Shrimps, Crabs, Snails: Monitor - The Candy Stripe Shrimp Lebbeus grandimanus is immune to its sting and lives in a commensal relationship with it.
    • Starfish: Monitor
    • Feather Dusters, Bristle Worms, Flatworms: Monitor
    • Clams, Scallops, Oysters: Monitor
    • Crabs: Monitor
    • Snails: Monitor
    • Sea Apples, Cucumbers: Monitor
    • Urchins, Sand Dollars: Threat
    • Nudibranch, Sea Slugs: Monitor
    • Copepods, Amphipods, Mini Brittle Stars: Monitor
    • Stony Corals: May be aggressive
    • Soft Corals: May be aggressive

Sex: Sexual differences

No sexual difference in appearance is known.

Breeding / Reproduction

The Christmas Anemone will divide in captivity, but there is no information on propagation of cold water anemones. It may be just like other anemones. Similar to other cold water anemones, they reproduce by fission or external fertilization of egg and sperm. When they spawn, they produce larvae that will float away and eventually find a spot to land. They then attach and develop a pedal disk that grows into a new anemone.

  • Ease of Breeding: Unknown

Ailments / Diseases

Problems for the these anemones are pretty minimal unless your lighting, water movement, feeding and water quality are low. Then your anemone will detach to look for "better conditions." In general, if your anemone moves, it is not happy. Make sure your lighting and water quality is good, and that the food you are offering is to their liking. Some predators include certain nudibranchs, sea stars, and snails.


The Christmas Anemone is generally unavailable to aquarists through retailers.


Author: Clarice Brough CFS, Carrie McBirney
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