Animal-World > Coral Reef > Sea Anemones - Tube Anemones

Sea Anemones ~ Tube AnemonesActiniaria and Ceriantharia

White Spotted Rose AnemonePhoto © Animal-World

     A beautiful anemone playing host to a colorful Clownfish, is a popular icon of the reef aquarium!

     Sea anemones have become very popular inhabitants for both the reef tank and the saltwater aquarium. Watching an anemone living in a cooperative relationship with a colorful Clownfish is a rewarding experience. There are 10 types of anemones that will host clown fish as well as many other types available for the aquarium. Many species are very hardy, and with careful selection all levels of marine aquarists can enjoy keeping sea anemones.

     Keeping sea anemones in captivity began way back in 1881, when the first anemone specimen was housed in a tub. A more intimate and dedication interest evolved in the mid-20th century. During this time, advances in SCUBA diving along with international jet transportation, made sea anemones much more available. They began being kept in reef tanks and saltwater aquariums around the world. They are also used as a food source by people in some areas of the Indo-Pacific and the Mediterranean, eaten as boiled or spiced anemones.

     Many anemone species are reasonably available and hardy. When selecting a sea anemone it is important to choose not only a hardy specimen, but also a healthy specimen. It is also important to choose an anemone that is suitable for your aquarium type. Most types of anemones do well in a reef tank, but there are a few that are better kept in a saltwater aquarium rather than a reef environment.

     Once established, many types of anemones are known to be quite hardy. However many anemones simply do not fare well in captivity. Much of their demise is attributed to the difficulty in the collection and handling of these delicate animals, but it can also often be attributed to their care after being obtained by the aquarist. Anemones vary in their aquarium hardiness and difficulty of care. Be sure to learn about the type of anemone you want so you can determine its needs and its suitability for your aquarium.

For information about setting up a reef tank see: Reef Tanks - Mini-Reef Aquarium Basics

Sea Anemones - Tube Anemones: Click on the small images below
for more information about each one.

Host Anemones - Clown Fish Anemone
Giant Carpet Anemone	Long Tentacle Anemone
Stichodactyla gigantea	Macrodactyla doreensis
Magnificent Sea Anemone	Merten's Carpet Anemone
Heteractis magnifica	Stichodactyla mertensii
Saddle Anemone	Sebae Anemone
Stichodactyla haddoni	Heteractis crispa

Rock Anemones - Family: Aiptasiidae
Brown Glass Anemone	Curlique Anemone
Aiptasia pallida	Bartholomea annulata
Glass Anemone	Small Rock Anemone
Aiptasia pulchella	Aiptasia diaphana
Trumpet Anemone
Aiptasia mutabilis

Sea Anemones - Family: Actiniidae
Christmas Anemone	Condy Anemone
Urticina crassicornis	Condylactis gigantea
Dahlia Anemone	Fish Eating Anemone
Urticina felina	Urticina piscivora
Giant Green Anemone	Painted Anemone
Anthopleura xanthogrammica	Urticina grebelnyi
Pink-Tipped Anemone	White-Spotted Rose Anemone
Condylactis passiflora	Urticina lofotensis

Sea Anemones - Misc Families
Caribbean Carpet Anemone
Stichodactyla helianthus

Sea Anemones - Tube Anemones: Don't see your favorite here?
Send us a picture and/or description and we'll try to include it!
Submit it Here

Sea Anemone Facts

     Sea Anemone facts: Anemones are invertebrates and they are also stinging polyps.

•      Anemones are invertebrates, as are 95% of the earth's creatures. Invertebrates are animals without backbones and most invertebrates are insects. However saltwater animals like sea anemones, corals, shrimps, snails, and crabs are also invertebrates.
•      Anemones are stinging animals that live their entire lives as a polyp, with the only exception being a short larval stage for some species. Anemones are benthic, which means they are attached to rocks or the sea floor. They mostly stay in one place waiting for fish or other prey to swim by close enough for them to ensnare them in their venom filled tentacles. Anemones in the aquarium will often move around until they find a place that they like and then stay put!
  

Sea Anemone Habitat

     These fabulous colorful animals are found in coastal waters throughout the world. Anemones live in shallow waters including the coral reefs, and in the deep oceans. They live in both tropical waters and cold waters. There are over 1100 described species and we are still being surprised by the discovery of new species. A most recently discovered species, an Antarctic sea anemone from the South Shetland Islands Stephanthus antarcticus, was found and described by Rodriguez & Lopez-Gonzalez in 2003.

Appearance of a Sea Anemone

     Anemones have a body that is radically symmetric and they come in a wide variety of colors. They are usually about 1 to 4 inches (2.5-10 cm) across, but a few species can be as small as half an inch (1.25 cm) across or as large 6 feet (1.8 m) across. The largest and most brilliantly colored anemones occur in coastal tropical waters.

     We can gain valuable clues about what anemones are - and how they look - from their scientific classification.

• Phylum: Cnidaria
       The phylum Cnidaria includes anemones, corals, jellyfish, and hydras. The term Cnidaria (with a silent "c") means "to sting", and this name refers to the cnidae, or nematocysts, which all Cnidarians have. The 'cnidae' are the stinging cells, which provide these animals a means of capturing prey and/or defending themselves from predators by inducing a painful sting.
       Another phylum name (older) for the Cnidarians is Coelenterata (pronounced "se-len-ter-a'-ta'). This name is from their old phyletic grouping, and may still be used informally in some settings when referring to these animals. Coelenterate refers to the single body cavity that serves as stomach, lung, intestine, and everything else! There is only one opening into this cavity, the mouth, through which everything passes in and out. The mouth is surrounded by several or many tentacles, which contain the nematocysts (cnidae) at their tips.
  
  
• Class: Anthozoa
       The class Anthozoa means "flower-like animals". Anemones are placed in this class of single or colonial polyps along with corals, sea fans, and sea pansies.
       The sea anemones are sometimes referred to as the ‘flowers of the sea'. They can be very colorful and can appear similar to flowers, but they are not plants. They are actually predatory, meat eating animals. Interestingly their common name ‘anemone' is derived from a group of terrestrial plants in the buttercup family. The plant genus Anemone consists of about 120 species of very pretty flowering plants.

Types of Sea Anemones

• The Sea Anemone
  Order: Actinaria
       Sea Anemones are in the order Actinaria, and are often called the "true anemones".
       They have an adhesive pedal disc or foot used to hold them in place, a hollow cylindrical or column shaped body, and an oral disc, or mouth, at the top which is surrounded by a circle of tentacles containing stinging nettle-cells or nematocysts. These stinging cells are used to capture prey and push it into its mouth. With only a slight touch, the tentacles shoot harpoon-like filaments into passing prey, injecting it with a paralyzing neurotoxin, and then guiding it into the mouth.
  
  
• The Tube Anemone
  Order: Ceriantharia
       Tube Anemones are in the order Ceriantharia. They are also known as Tube-dwelling Anemones or Burrowing Sea Anemones. They are solitary animals, living and withdrawing into tubes that are buried in soft sediments.
       Tube Anemones look very similar to sea anemones, but they have elongated bodies adapted for burrowing and they lack the pedal disc or foot. The cylindrical shaped body is covered by a tube of secreted mucous and is usually hidden in the muddy substrate. The mouth is on a central disk, surrounded by short tentacles in the center and longer tentacles on the margins. Usually only the tentacles are visible above the ground..

Hardy Aquarium Anemones

     Some anemones are easier to keep than others. The best anemone survival rates that we have found are among the smaller anemones and also one of the carpet anemones, the saddle anemone. Another anemone that is very common is the Bubble Tip Anemone Entacmaea quadricolor, also called the purple base or pink tip anemone. This is fortunate since many different kinds of clownfish will accept the purple base anemone as a host.

     Clownfish host anemones that are easier to keep include:

• Bubble Tip Anemone Entacmaea quadricolor
• Saddle Carpet Anemone Stichodactyla haddoni
• Long Tentacle Anemone Macrodactyla doreensis
• Delicate Sea Anemone Heteractis malu

     Other hardy anemones include:

• Caribbean Anemone Condylactus gigantea
• Tube anemone species (Burrowing Sea Anemones)
• Glass Anemones in the Aiptasia genus (though these are also considered to be pests!)

     Some of the more difficult anemones to keep include:

• Sebae Anemone Heteractis crispa
• Giant Carpet Anemone Stichodactyla gigantea
• Magnificent Anemone or Ritteri Anemone Heteractis magnifica

     We have found that anemones are often challenging. We have purchased almost every anemone available and have read surveys taken in an attempt to determine the survival rate of anemones once they enter into the aquarium industry. In both cases the survival rate is very low, particularly among the larger carpet anemones. This is unfortunate as the larger carpet anemones are natural hosts for a number of anemone fish, but fortunately clown fish will take other kinds of anemones as hosts.

     One of the best books we have found on anemones and their care, and the main reference for information presented here, is the book seen to the right above. It is the "Field Guide to Anemonefishes and their Host Sea Anemones" by Daphne G. Fautin & Gerald R. Allen. Both of these authors believe that carpet anemones should not be removed from the oceans for the aquarium trade.

Clown Fish Anemone

     Sea anemones have special relationships with other animals and organisms, where each animal helps the other in some way. Perhaps the most well known relationship is that of some sea anemone species providing a home and protection for clownfish. In return the clown fish help the anemone by cleaning its tentacles of detritus, and possibly running off potential predators.

     Though there are over 1100 types of sea anemones, only 10 species are known to host Clownfish:

• Adhesive Sea Anemone Cryptodendrum adhaesivum
• Bubble Tip Anemone Entacmaea quadricolor
• Beaded Sea Anemone Heteractis aurora
• Sebae Anemone Heteractis crispa
• Magnificent Anemone or Ritteri Anemone Heteractis magnifica
• Delicate Sea Anemone Heteractis malu
• Long Tentacle Anemone Macrodactyla doreensis
• Giant Carpet Anemone Stichodactyla gigantea
• Saddle Anemone Stichodactyla haddoni
• Merten's Carpet Anemone Stichodactyla mertensii

Sea Anemone Care

     Zooxanthellae:
     Most anemones survive in a symbiotic relation with with a marine algae called zooxanthellae. The zooxanthellae are photosynthetic organisms whose waste products are used by the anemone for food. Since the zooxanthellae require light to carry on photosynthesis, anemones in turn require bright light to thrive in the aquarium. The zooxanthellae are generally a light brown color, the same color as the light brown leather corals that also harbor zooxanthellae. The loss of zooxanthellae, apparent by a whitening of the anemone, usually means the anemone will slowly grow smaller and smaller until it dies.

     What do sea anemones eat?
     Sea anemones are carnivores, meaning they are meat-eating animals. Though they obtain most of their nutrition from zooxanthellae, symbiotic algae that lives inside their tissues, they will also eat other proteins. Sea Anemones will eat fish, mussels, worms, shrimp, and zooplankton like copepods, isopods, amphipods, and other small crustaceans, and tiny marine larvae. In order to eat, they must wait for their prey to swim by, then sting and ensnare it with their tentacles, and finally guide it into their mouth

     Marine lighting: How much light for anemones?
     Many anemones need lots of light to do well. They need light to support zooxanthellae, symbiotic algae that live inside their tissues and from which they obtain most of their nutrition. Provide 2 to 5 watts per gallon, preferably with some blue spectrum provided by actinic light bulbs or higher temperature metal halide lighting.

     The scale of light intensity is:

• Low level:
  1 to 2 watts per gallon, about a normal marine setup with regular fluorescent bulbs (10 watts per foot bulbs).
• Medium level:
  2 to 4 watts per gallon, maximum regular fluorescent to minimum VHO or metal Halide.
• High level:
  5 or more watts per gallon, maximum VHO and/or metal halide.

See Mini-reef: Lighting for a description of VHO and metal halide lighting systems.

Sea Anemones Life Cycles

     There are two methods by which sea anemones can reproduce, either by sexual reproduction or by lateral fission.

• Sexual reproduction:
  Sexual reproduction is where the anemones release eggs and sperm into the water, which then producing free-swimming larvae.
• Lateral fission:
  Lateral fission is a system of budding, where an identical animal sprouts from the side of the parent anemone, growing until it can survive on its own. Because of its ability to reproduce by lateral fission or budding, pieces of an anemone can turn into new sea anemones.

     Anemones are long-lived animals, with some species of sea anemone living 50 years or more.

Sea Anemone Predators

     There are few sea anemone predators. When an anemone feels threatened, it will pull its tentacles into its body giving it a round ball-like appearance. Though there are very few animals will eat anemones, there are some that do prey on them. Anemone predators include:

• nudibranchs
• snails
• fish
• sea stars

     Some specific predators are the Grey Sea Slug Aeolidia papillosa, which feeds exclusively on sea anemones, and also the Tompot Blenny Parablennius gattorugine, which enjoys snacking on them if it gets a chance.

Buy Sea Anemone - Checklist

     Successfully keeping an anemone is often dependent upon choosing a healthy specimen when you buy sea anemones. Some things to avoid when choosing an anemone are:

• Loose or open mouths
• Tentacles that are short when they should be long, or skinny when they should be fat
• There should not be any tears on its foot
• An anemone should be a little bit sticky.
• Coloring - if an anemone is white, it may have released its zooxanthellae that it depends on for much of its food. This can spell disaster over time.
• Anemones that are not attached to anything may have trouble attaching.
• Anemones contract when they feel threatened, make sure the anemone you get reacts when it is picked up

     There are many naturally colored anemones, but occasionally artificially colored anemones are offered for sale. Primarily these are Sebae or Ritteri Anemones colored with vegetable dyes or other dyes to increase their salability. This coloring doesn't add to the anemones vitality, nor does it last.

Sea Anemone Pictures

Genus: Aiptasia

     This anemone is so hardy it is considered a pest in mini-reef aquariums. Many articles have been written on how to get rid of them, from injecting them with kalkwasser, to using aquastick (an underwater epoxy) to seal them into a hole in the rock! Apparently if they are smashed or removed by hand, small pieces of the anemone will re-grow to adult Aiptasia. Aiptasia are not used by clownfish probably because they are too small.

Curlicue Anemone

     We are not sure what the scientific name of this anemone is. It has beautiful, delicate tentacles. It prefers medium to high light conditions but will survive in low light as well. This is not a clownfish host.

Bubble Anemone- with two Sebae Clowns
Entamaea quadricolo

     This is a hardy anemone that likes medium to strong light and does well in aquariums. Many different kinds of clownfish will accept it as a host. We had a pair of Cinnamon clowns breed in a bubble anemone repeatedly for over a year. Pictured with the anemone above are Sebae clowns.

Tube Anemone
Pachycerianthus mana

     Tube anemones are one of the few that do well in low light levels. They are nocturnal and should be fed chopped fish and shrimp every other day or so. They build a tube out of mucus and detritus found on the substrates they inhabit. Tube anemones are found in all the warm water oceans of the world. Their long tentacles have a powerful sting and therefore should be kept away from other anemones and corals. They are not used as hosts by clownfish.

Color Variations

Caribbean Anemone Condylactus gigantea

     These are an inexpensive anemone which come from the Caribbean. They are usually very hardy and come in several colors. The most attractive have purple tipped tentacles. Condylactus like high light levels but will do okay in low to medium light. These anemones are the most inexpensive and are very hardy. They can do well in any marine aquarium, not just reefs!

Long Tenacled Anemone
Macrodactyla doreensis

     This anemone will get fairly large (we have one that is the size of a dinner plate) and is accepted by many different kinds of clownfish. We have personally seen Tomato, Sebae, Percula, Skunk, and Maroon clowns accept it as a host. They are usually hardy and easy to keep as long as you have medium to strong light.

     This looks like a variety of tube anemone but we're not sure.

Saddle Anemone
Stichodactyla haddonni

Photos  © Animal-World

     The Saddle anemone, pictured above, has a lot of very short tentacles. They are very adhesive to human skin. If you touch one it will stick fast, sometimes to the point of pulling the tentacles out of the anemone when you detach it. There is a rarer form of the Saddle anemone which has lighter stripes running from the mouth (center) to the outside edge. The Saddle anemone is by far the hardiest of the carpet anemones. It likes strong light levels.

Back to Coral Reef