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Cerianthus lloydii

The pretty North Sea Tube Anemone offers a great display option for a large cold water aquarium!

The North Sea Tube Anemone Cerianthus lloydii is appreciated for its beauty and durability. It comes in a variety of colors making it a prized display in a cold water aquarium. Its column can be brownish or a pretty light yellow. It’s topped with tentacles that are usually brown, white, or green, and sometimes they can have dark brown bands. At times the tentacles can be orange in color as well, so it’s also known as the Orange Tube Anemone.

The C. lloydii shares the unique traits of all the tube dwelling anemones. Its soft body has an elongated cone-shape with its crown of non-retractable tentacles on one end, and a pointed foot on the other. It uses the pointed foot to burrow deep into a sandy or muddy substrate, leaving only the oral disc and tentacles exposed on the surface. Once in the substrate it builds a cylinder in a vertical burrow as much as 15 in (40 cm) deep. Some other common names for this species are the the Lesser Cylinder Anemone and Tube Anemone.

The term ‘ tube dwelling anemone’ is derived from their ability to build a this cylinder, or tube, to live in. It was previously believed that they created their tube by releasing a mucus, which then become covered with sand. Today, however, it is known that they create the tube by releasing threads of a special type of nematocysts called ‘ptychocyst’. The result is a woven fibrous structured of stinging cells that help protect it from attack. Though its tentacles are non-retractable, if it is frightened or disturbed it can instantly withdraw its whole body into the tube and hide.

The North Sea Tube Anemone is a relatively hardy, durable animal when provided with the right environment. It is moderate to care for and will thrive with moderate filtration, low current, subdued lighting, and feedings twice a week. However, because it needs a large tank and cooler marine environment, it is suggested for the intermediate to advanced aquarist. These anemones need to be kept in a good sized aquarium with a deep sand substrate to accommodate their burrowing behavior and ability to sweep quite wide with their long tentacles. Being a cold water species, a chiller is also needed to maintain optimum health.

They can be kept with large fish, but be sure to provide plenty of room for tankmates to keep them out of reach of its stinging tentacles. They do not get along with other anemones, but they do get along fine with their own kind, as long as only the tips of their tentacles touch. In the wild, they form dense lawn-like colonies.

For more facts about Tube-Dwelling Anemones, see:
Tube Anemone – Burrowing Sea Anemone

North Sea Tube Anemone, Cerianthus lloydii

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Species specific tank display

The North Sea or Orange Tube Anemone are one of the easier tube anemones to care for. The orange can be brought out with 20K or actinic lighting. They do not need strong lighting but they need very gentle water movement and a deep stand bed to bury their tube that they live in. Some have successfully used PVC that is 1.5 times as long and as wide as the anemone with the bottom closed off. Put in the anemone in 4/5s of the way and back fill with mature sugar fine sand. Be mindful where the anemone is placed as it will grow and open quite wide, although it may look small now.

North Sea Tube Anemone – Quick Aquarium Care
  • Minimum Tank Size: 50 gal (189 L)
  • Aquarist Experience Level: Intermediate
  • Temperament: Semi-aggressive
  • Temperature: 55.0 to 72.0° F (12.8 to 22.2&deg C)
  • Size of organism – inches: 6.0 inches (15.24 cm)
  • Diet Type: Carnivore
  • Suitable for Nano Tank: No

Habitat: Distribution / Background

The North Sea Tube Anemone Cerianthus lloydii was described by Gosse in 1859. The Cerianthus genus is a member of the Cerianthidae family and contains about 20 species. The C. lloydii are found in the North Atlantic/Baltic Seas and North Sea. They are found along the coast of Europe, from Biscay to Norway, and the coast of Greenland and Spitzbergen. This anemone is not on the IUCN Red List for endangered species. Some other common names it is known by are the Lesser Cylinder Anemone, Orange Tube Anemone, and Tube Anemone.

North Sea or Orange Tube Anemones inhabit soft substrates like sand and mud where they form dense lawn-like colonies, although they can also be found in rock crevices. They are most commonly found at depths of 6 – 131 feet (20 – 40m), though occasionally as deep as 328 feet (100 m). Like other tube anemones, they capture very small prey and are heavily populated in waters where the plankton is very dense. They also eat detritus.

  • Scientific Name: Cerianthus lloydii
  • IUCN Red List: NE – Not Evaluated or not listed


The North Sea Tube Anemone can reach 6″ (15 cm) in length, and topped with non-retractable tentacles that can be up to 2″ (5 cm). Its vertical burrow can be as much as 15″ (40 cm) long. It is unknown how long they live, but in the wild they may live many decades. Some tube anemone species that were introduced into the aquarium at Naples, at its inception, are now over 100 years old.

Tube Anemones differ from sea anemones both internally and externally. Unlike true anemones, they have 2 different sets of tentacles on their oral disc and they lack a pedal disc foot, used to attach to surfaces. They also differ from many true anemones in that they lack zooxanthellae.

The C. lloydii has a long, cylindrical, somewhat cone-like body that does not have a foot, but a blunt point. They deflate and condense their body to drive into sand or mud. Once in the substrate they construct a very long tube. This structure is fibrous, with woven threads of stinging cells to help protect it from attack.They do not form a “ball†like other anemones do to hide, rather they retract into their “tube.†Disturbances that can cause it to retract are direct sunlight, a strong touch, and excessive feeding. Usually the tube is cream colored, but can range from brown or tan to shades of purplish red.

The North Sea Tube Anemone has an oral disc with a crown of more than 70 tapering, non retractable tentacles, and a mouth in the center. The long outer tentacles around the margin of the oral disc are usually brown, green, white or with dark brown alternating bands. These delicate tentacles typically are bioluminescent. The shorter labial tentacles, located over the mouth, are darker colored versions of the longer tentacles.

The C. lloydii takes food in and expels waste through its central cavity, or mouth. It spreads its longer tentacles over the surface of the mud or sand to capture prey. The smaller tentacles are used to manipulate foods into its mouth. Tube Anemones use their bioluminescent tentacles to startle fish, thus keeping fish from nibbling on them. The potency of the toxins in tube anemones has been shown to have little effect on test subjects, unlike true anemones, on which their toxins had lethal effects.

  • Size of organism – inches: 6.0 inches (15.24 cm) – This anemone’s tube length can be up 15″ (40 cm) long.
  • Lifespan: 30 years – It is unknown how long they live, but some tube anemone species have survived for more than 30 years in public aquaria.

Difficulty of Care

Coming from temperate waters, North Sea Tube Anemones can be moderate to care for. They are best kept by intermediate to advanced aquarists as they have specific needs. This tube anemone needs a cold water environment and they require a lot of space. They need a large enough aquarium to satisfy their burrowing behavior and their ultimate size, and the temperature needs to be kept between 59 to 72° F (15 to 22°C), which that requires a chiller.

Take care when selecting tankmates, as feeding is another big issue if there is any competition for the meaty foods they need to survive. Zooplankton and other marine tidbits are often consumed by fish and invertebrates before this anemone gets a chance to eat. A species specific tank or one that is very large and mature is best.

When choosing a C. lloydii, make sure the color is good, the mouth is not gaping open, and there are no tears. When being transferred from another aquarium, a healthy specimen should immediately retract, ejecting the water from its mouth.

Check that the tube is intact and in good condition. If the tube is missing, that can create challenges. Although they can re-grow the tube, it takes a lot of energy that sometimes will deplete the animal into a weakened condition. If they have difficulty creating a tube, you can provide a section of acrylic tubing for it to live in. Place the tubing at an angle in the sand, but be certain that both ends are unobstructed and there are no sharp edges.

  • Aquarium Hardiness: Moderately Difficult
  • Aquarist Experience Level: Intermediate – Best kept by an Intermediate to advanced aquarist.

Foods and Feeding

The North Sea Tube Anemone is a carnivore and will generally accept small meaty foods in captivity. It can be offered finely minced krill, fish, shrimp and/or frozen or live brine or mysis shrimp. Be careful not to feed with large pieces of food since they will damage the delicate tentacles. This anemone is nocturnal so feed nightly, or when they emerge. If you have a lot of copepods, amphipods, or other small prey in the tank, then feed twice a week.

  • Diet Type: Carnivore
  • Flake Food: No
  • Tablet / Pellet: No
  • Live foods (fishes, shrimps, worms): Some of Diet – Live brine or mysis shrimp, zooplankton, copepods, and amphipods.
  • Liquid Foods: Some of Diet – Liquid with zooplankton.
  • Meaty Food: All of Diet – Meaty foods must be very finely minced or they can damage the anemone’s delicate tentacles.
  • Feeding Frequency: Daily – This anemone is nocturnal, so feed nightly after the main lights go out or when they emerge.

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. Waste production created by your anemone can be calculated in inches. Basically, every inch of anemone is equal to an inch of fish, so a 6″ tube anemone produces a bio-load equivalent to that of two 3″ fish.

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. Poly-fiber can be cut and used in sumps, etc. A good protein skimmer is a must.

Although anemones are not as dependent on calcium as stony corals, magnesium and calcium is still needed to keep the pH and alkalinity stable and within the correct parameters. Additions of trace elements are suggested. Phosphates should be kept around 0.03 or less.

  • Water Changes: Bi-weekly
  • Calcium Levels: 380.0 – 450.0 ppm – Helps to balance alkalinity. Aim for 420 ppm, or 385 ppm if you are using Seachem calcium.
  • Alkalinity Levels: 7.0 – 11.0 dKH – (2.4 to 4 meq/L) Aim for 7 dKH or 3.5 meq/l for reef tanks.
  • Magnesium Levels: 1,250.0 – 1,350.0 ppm – Test magnesium levels and adjust before checking Calcium.
  • Strontium Levels: 5.0 – 15.0 ppm – Aim for 8 ppm.
  • Iodine Levels: – .030 to .060 ppm: Control is not recommended.

Aquarium Setup

The typical reef environment with a sand substrate is what is needed for your North Sea Tube 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. A mature 50-gallon tank that is at least 9 to 12 months old is needed to provide a stable environment.

They must have a very deep fine sand substrate, with enough depth to accommodate their total length. Hitting a bare bottom, as well as trying to burrow through course gravel (rice sized or larger), will prevent the C. lloydii from finding a spot to burrow and settle. This can cause them to stress and die. A consistently high quality water that is well oxygenated is necessary for their survival. They don’t tolerate turbulent waters, so an ozonizer is the best solution for increasing oxygen content. A good protein skimmer is a must.

Live rock is fine, however you don’t want so much that it takes up valuable bottom real estate. The sand needs to be quite deep, just a couple inches of sand is not enough. A trick when you don’t have a deep enough substrate is to use a PVC tube that is 1.5 times longer than the animal. Place the animal’s tube into the pipe about 4/5’s of the way, pour fine sand around the animal, and fill to the top. Gluing a solid base at the bottom end will prevent the sand from coming out if you have to move it. Some aquarist also suggest pots, or built up areas on one side of the aquarium. Be sure their delicate tentacles are not within reach of power heads.

  • Minimum Tank Size: 50 gal (189 L) – The tank needs to accommodate an anemone length of at least 15.”
  • Suitable for Nano Tank: No
  • Live Rock Requirement: Typical Amount – A little less is fine for cold water marine tanks.
  • Substrate Type: Sand – Deep fine sand bed.
  • Lighting Needs: Low – subdued lighting – Low, actinic lighting brings out their colors.
  • Temperature: 55.0 to 72.0° F (12.8 to 22.2&deg C)
  • Specific gravity: 1.023-1.025 SG
  • Water Movement: Weak – Low, as too much turbulence can cause them to get washed out of their tube, but the water does needs to be highly oxygenized.
  • Water Region: Bottom

Social Behaviors

The North Sea Tube Anemone is semi-aggressive, yet as far as “anemone†type corals go, they do not have as powerful of a sting as true anemones. Care should be taken to provide other corals with plenty of room. Make sure when the North Sea Tube Anemone comes out at night, their tentacles do not come in contact with delicate corals.

Several North Sea Tube Anemone specimens can be kept in an aquarium, but they are not compatible with other anemone species. Though they do coexist with their own kind, they do not get along with their “warm†water tube anemone cousins either.

They can be kept with large fish, as they are not disturbed by them, but they do not host clownfish. Fish that do not compete for food would be best., and avoid fish that are interested in “worm like” prey. As for other invertebrates, avoid burrowing snails that can upset their sandy home. Also avoid crabs which may bother them while they eat.

  • Venomous: Yes – Very weak sting.
  • Temperament: Semi-aggressive
  • Compatible with:
    • Same species – conspecifics: Yes
    • Anemones: Threat
    • Mushroom Anemones – Corallimorphs: Monitor – Keep them out of reach of the anemone.
    • Leather Corals: Monitor – Keep them out of reach of the anemone.
    • Zoanthids – Button Polyps, Sea Mats: Monitor – Keep them out of reach of the anemone.
    • Sponges, Tunicates: Monitor – Keep them out of reach of the anemone.
    • Shrimps, Crabs, Snails: Monitor – Crabs may steal their food.
    • Starfish: Monitor – Starfish may get tangled in the anemone’s delicate tentacles and tear them.
    • Feather Dusters, Bristle Worms, Flatworms: Monitor – Keep them out of reach of the anemone.
    • Clams, Scallops, Oysters: Monitor – Keep them out of reach of the anemone.
    • Snails: Safe – Avoid burrowing snails that can upset their home.
    • Sea Apples, Cucumbers: Threat
    • Urchins, Sand Dollars: Monitor
    • Nudibranch, Sea Slugs: Monitor
    • Copepods, Amphipods, Mini Brittle Stars: Safe
    • Stony Corals: May be aggressive – Keep them out of reach of the anemone.
    • Soft Corals: May be aggressive – Keep them out of reach of the anemone.

Sex: Sexual differences

The C. lloydii are hermaphrodites, meaning each specimen develops as both male and female. At a smaller size it is a male. After crossing over to a larger size/age, it will turn into a female.

Breeding / Reproduction

The North Sea Tube Anemone has not been bred in captivity and cannot be propagated. However, larvae captured in plankton has been successfully reared repeatedly. The C. lloydii reproduce sexually with the female being larger than the male. Unlike the true anemones, they do not reproduce through asexual means such as fission, where the anemone is divided or split into parts to create a new anemone.

C. lloydii are hermaphrodites, meaning they are both male and female. Although each animal can produce both eggs and sperm, they do not produce them at the same time, so it takes two specimens to produce a zygote. The Zygote is a fertilized egg, the beginnings of a new North Sea Tube Anemone.

In the wild, they first release sperm and then eggs into the water column, where cross fertilization takes place. Planula larvae development lasts for 3 to 4 months. The larvae have an internal yoke sack that is believed to help sustain them. This larvae then drops, develops into polyps and settles into the sand, and constructs a tube. They will also reproduce asexually by budding off.

  • Ease of Breeding: Difficult – In captivity, larvae captured in plankton has been successfully reared repeatedly.

Ailments / Diseases

North Sea Tube Anemones are usually hardy and problems are pretty minimal if they are provided with an adequate environment and fed regularly. There is not a lot is known about potential ailments, these anemones seem to be either alive and very well, or dead.


The North Sea Tube Anemone, and others members of the Cerianthus genus are not easy to find in stores or online. Usually they will be sold under “tube anemone†without the proper scientific name. You will need to inquire as to their origin in order to determine how to care for them properly, in terms of water temperature.


Featured Image from Openverse