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Related Articles: Anemones in Captive Systems, LTAs, Heteractis crispa/Sebae Anemones, Invertebrates, Stinging-Celled Animals, Clownfishes, Aiptasia/Glass Anemones, Anemones of the Tropical West Atlantic, Colored/Dyed Anemones,

/Diversity of Aquatic Life Series

Entacmaea quadricolor. Bubble Tip (BTA), Rose Anemones in Captive Systems

By Bob Fenner

"Workin' 9 to 5 what a way to make a livin'

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Anemone Success
Doing what it takes to keep Anemones healthy long-term

by Robert (Bob) Fenner

In any given field of endeavour there is a certain "best"... Mohamed Ali in boxing, Tiger Woods for professional golf, myself for king of procrastination... For large species of anemones, the choice hands down has got to be the Bubble Tip Anemone or BTA for short. This exemplary organism is relatively hardy and adaptable... not too large for most hobbyist sized systems, accepting of a wide range of readily-available foods... And there's more! It's been serially reproduced in captivity via vegetative/asexual fission ("fragging"), intentional and not, in good numbers... dropping its price appreciably... and to top it all off... it's a good looking addition to "reef quality" settings!

As with all large anemone species there are caveats re mixing it with other Cnidarians (though this can be done) and unfamiliar fish species, as well as providing adequate lighting, filtration, feeding... These we'll cover in turn here. Know though, that Anemones, albeit none easy to keep, this one is hands-down the species most likely to do well when taken care of properly.


Amongst the large species of anemones on offer to hobbyists, likely only the "Sebae" or Leathery Anemone, Heteractis crispa is more readily identified... with its prominent pink tipped narrowing tentacles. The "four color" Entacmaea is generally also distinctive, with its varyingly bulbous enlarged tentacular tips. Shown with Amphiprion bicinctus in the Red Sea and a close-up of tentacles in Wakatobi, S. Sulawesi, Indonesia at right. Their columns (pedicles) are straight, columnar and smooth... that is, they lack the warty, raised verrucae of other large symbiotic anemone species. Usually brownish in color, some bases are green or reddish. Their oral discs are the same color as their tentacles.

The Bubble Tip occurs in a myriad of colors: Most are tan to brownish, but green, orange, pink, grading to bright reddish and purplish individuals can be found. These last are often referred to as Rose and Maroon Anemones. They are all Entacmaea quadricolor.

Entacmaea quadricolor (Ruppell & Leuckart 1828), the Bubble-Tip or Bulb-Tentacle Sea Anemone. Family Actiniidae. This is historically the hardiest of large, naturally symbiotic Clownfish anemones for aquarium use... many more specimens are collected and received in tact, in reasonably good health from the wild to distributors. And more and more folks are offering very hardy "fragged" individuals that are asexual cloned aquacultured specimens.

(from Fautin 2006)

Class: Anthozoa Subclass: Hexacorallia Order: Actinaria Suborder: Nyantheae, Carlgren 1899 Tribe: Thenaria, Carlgren 1899 Subtribe: Endomyaria, Stephenson 1921 Family: Actiniidae, Rafinesque 1815 Genus: Entacmaea, Ehrenberg 1834 Species: Entacmaea quadricolor (R?pell and Leuckart, 1828)

Distribution: Of the large Indo-Pacific anemones that are naturally symbiotic with Clownfishes, Entacmaea is the most widespread; found in the Red Sea, along Africa's east coast, throughout the Indian Ocean to the Western Pacific; Australia to S. Japan, out to Micronesia and Melanesia. Some examples below a close-up in Sharm el Sheik, Egypt's Red Sea, a greenish one in N. Sulawesi, Indonesia and an orangish specimen in Fiji.

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The issue of most note to aquarists is "bubbliness" of this species tentacular ends. Loss of "bubbles" has been speculated to be due to insufficient light, current, feeding, presence of host fish/es, reaction to competitive influence/s... At this moment "the jury is still out" on this issue. The degree of bubbled-ended-ness does seem to be positively correlated with more current, less feeding, the presence of symbionts and other Cnidarians though. The bubbliness is evidently not a matter of life/death, good/bad... as specimens of both can/do well, and they do change back/forth at times from no apparent provocation.

Bubbly and not-so-bubbly Entacmaeas in the wild. First in the Red Sea (note the teeny 3-Spot Damsel...) and N. Sulawesi/KBR.

The degree of overall "fullness" or tumescence can be an issue, with some expansion and contraction thought to be used as a means of "flushing" the animal's insides... However, staying closed or flaccid is a bad sign... of damage from host et al. livestock, perhaps something amiss with water quality, or other adverse environmental factor. Best to be pro-active concerning such events... Testing water, at the very least cleaning the skimmer and doing a good-sized/percentage water change.

Moving about the system is NOT normal behavior once a specimen becomes settled... It IS indicative of some change in said system. Waning light quality and/or quantity, changes in circulation patterns, a paucity of food... Something has changed that is altering the animal's concept of the suitability of its placement. Do NOT move these animals yourself unless this is absolutely necessary.

Why does your specimen hide? Maybe it considers that something is frightening it... perhaps it's satisfied with its situation and is simply avoiding predation. BTAs w/ and w/o hosting fishes will at times "hunker down" for a while. This behavior alone is not a sign of trouble.


THE big question with most large anemone stocking is whether they can be maintained with other Stinging-celled life, particularly hard and soft corals... among other Classes and Orders... as well as other Anemone species. The simple answer is yes, this can be done... with certain provisos.

Delbeek (2002) related the keeping of Entacmaea with other species in a large semi-open system of some 350 gallons at the Waikiki Aquarium. ("...including a Merten?s sea anemone Stichodactyla mertensii, several Heteractis crispa, and a large number of E. quadricolor (these had multiplied via fission several times over the years producing over twenty offspring)."). Note the size/volume of this system... Keeping anemones in small systems with other Cnidarians, including other anemone species is NOT advised... there being too much chemical and physical and biochemical-physical negative interaction to warrant the health of all livestock. Starting with initially smaller specimens, taking care to place the "less aggressive" species ahead of more so, distancing all appropriately, and being very diligent re your maintenance (water changes, activated carbon...) allows for more likelihood of all getting along... with the anemone placed last. Even then, the onus is upon you to keenly observe your livestock. Should other stinging-celled life proliferate, grow too close to your BTA/s, they may become very unhappy, try to move, shrink to tiny proportions, or outright die.

More than one cloned BTA can survive quite well in the same system, and this can be not only a pleasurable way of populating your system, but a useful trade-in item to offset your hobby addiction's costs.

Fishes that form symbiotic relationships with the BTA abound. Thirteen Clowns (the most of any Anemone) pair up with Entacmaea in the wild. Most all Damsel/Clownfish species that will pair up with giant anemones may form a relationship with this species in captivity.

Clownfish/Damsel Species Naturally found with BTAs (After Fautin 2006)
Amphiprion akindynos, Barrier Reef Clownfish
A. allardi, Allard's Clownfish
A. bicinctus, Red Sea Clownfish
A. chrysopterus, Orangefin Clownfish
A. clarkii, Clark's Clownfish
A. ephippium, Saddle Anemonefish
A. frenatus, Tomato Clownfish
A. fuscocaudatus, Seychelles Anemonefish
A. latezonatus, Wide-Band Anemonefish
A. melanopus, Red & Black Anemonefish
A. polymnus, Saddleback Anemonefish
Premnas biaculeatus, Spine-Cheek Clown
Dascyllus trimaculatus, Domino Damsel

Do note that the above list and general statement re symbiotic relations of these species is not a given, some species/individuals take a few minutes, to hours or days to never to bond. Nor is such a relationship necessarily likely to be healthy for the anemone. In the wild it is rare to find the BTA sans fish host/s... and one NEVER finds Clownfishes w/o host anemones... at least not for long. In captivity though, one or more Clowns may be so aggressive in their seeking cover with especially a new anemone host of small size, that they damage it to the point of danger to death. You should place an anemone when you can be present to observe how extensive this trauma may be, and have a plastic guard of sorts (like an inverted strawberry basket) to keep the Clown/s off should they appear too eager. If it is your desire to showcase the Clown/Anemone relationship in your system, you are encouraged to place the Anemone first, allow it to fully acclimate (perhaps for months), introducing the clowns later... ideally at small size.

Not all fishes get along with anemones... One of their chief predators are marine Angelfishes for instance. Held off often by the hosting Clownfishes found in the anemone. Be wary of placing large predaceous species like big wrasses, large and small puffers (even Tobies may nip them), Triggers and such in a system with your anemone. And some fishes end up as Anemone meals... particularly aloof, weak swimmers like Mandarins and easily attention-diverted diggers like Jawfishes. Other poor-visioned fishes like Morays require the placement of your Anemone (and other sessile invertebrates) in a bommie sort of setting, with rock piled/arranged in a stable fashion in a pyramid like form... to grant bottom space for the eel, heights for the non-eel.

Other invertebrates, motile and attached are generally not problematical, with the exception of crabs, which should never be trusted around other livestock period.

Be aware of the potential for food-poaching by tankmate fishes, shrimps and other livestock... Having a Clownfish or more as symbiont/s can help here, but it is not uncommon for them to "feed from the hand/tentacles that protect them".


Appearance and behavior are paramount in selecting a healthy specimen. Look for a full, cylindrical body and tentacles that are to some degree bubbled at their tips, not small and clubbed, nor shriveled.

Is the animal attached to a rocky surface? It should be stuck to something... Don't buy a specimen that is not attached... Look at the foot... if the BTA is not connected as it would be in the wild, it is likely torn... and has a much greater chance/potential of dying in your system. DO buy the rock the anemone is attached to.

Size matters... all wild-collected BTAs are "about full/adult size"... There are two "ecotypes" of specimens... one deeper and solitary, the other shallower water and more communal. The former are often greenish to greenish-brown, and can grow much larger... up to 50 cm. (20 inches across), whereas shallow water ecotype individuals tend to be warmer colored, browns to orange to pink and red, and smaller (to 30 cm., 12 in.) in diameter. The larger of these two tends to be less aquarium hardy and reproduces mainly sexually, whereas the shallower water ones are easier and generally reproduce through asexual fission. All wild-collected (as opposed to the often-smaller captive clone produced which can indeed be small/er) ones are a hand size or so across... Avoid too-small specimens, as these can fall irreversibly into poor health easily. Often folks consider that theirs is "really growing", not realizing that it is simply the expansion with water that accounts for grander appearance. Do NOT buy small (under 3" if wild-collected) specimens is my point here. Something has gone wrong with these... if new, likely tearing... If they've been on hand days to weeks or more, perhaps beating by host fishes or poor conditions are at play. This being stated, akin to the "Goldilocks and Three Bear" story, too-large specimens can be trouble as well... shipping poorly, getting torn more easily, not adapting well to captive conditions. I would avoid specimens more than hand-size... let's say six inches in diameter. All of this is easily negligible given the availability of captive-produced stock. Most all of these animals move, adapt and live well in captive settings.

Unless the specimen is actively feeding, discharging wastes or sex products, the mouth's "lips" should be tightly closed. Loose, everted and the worst, gaping lips/mouth are an indication of poor health.... quite possibly near-death.

Avoid bleached specimens... Though you may feel obligated to "rescue" such from your dealer, these specimens take a very long time to rally (perhaps a year or more) if at all. And, please, avoid any day-glo pink, multi-colored obvious dyed specimens. This practice is most common with the Sebae or Leather Anemone (Heteractis crispa) but does occur at times with BTAs.


Anemones do not "like" new, changeable environments. It is strongly advised to wait a good half year or more for your system to "age" before introduction. What the "do" like are stable, optimized conditions... Most often granted only with systems of size... Large volumes change less quickly should the power go, a pump stop, a heater break... or an organism dies unseen... or the tank gets overfed. The smallest volume I'd place a large anemone species in is a hundred gallons (this animal easily grows, expands to a foot across when healthy)... Twice this if you intend to also keep other Cnidarians present. These are decidedly NOT "mini-reef" organisms. Anemones need constant "reef" quality environments.

In the wild Entacmaea is most often encountered in rocky crevices... wedged twixt... and if disturbed, pulled back out and away from touch. Positioning your specimen in such an area (it will move itself... please allow it to do so) will aid its settling in. Having lots of good quality live rock, live sand (either purchased or made from inoculated LR) with its complementary assortment of infauna is requisite. I've already mentioned the value of bommies... free-standing piles of rock to isolate your anemone from eels, and other stinging-celled life... These are really neat means of isolating (using the sand/gravel as a functional "moat" your anemone/s.

Changes to their environment, with new water (pre-mixed and stored ahead of use), lighting, circulation... new live rock et al. should be done gradually. LR should be cured elsewhere before introduction, lighting should be on timers, and new lamps switched out, (and screened/controlled over time...) not all at once.

On the subject of light/lighting, this species is a moderate one in terms of intensity... 4-5 watts per gallon or so (more is fine) of high CRI, 6,500 K plus temperature is about right. MH and HQI are preferable, particularly for deeper water (more than 18" let's say), but boosted fluorescents of enough wattage will work.

Likely the most ridiculous source of loss of these animals is their getting sucked up against pump, powerhead, overflow intakes... DO bear in mind that most BTAs stay put, ONCE established... and being well-fed. However, there is a surprisingly large percentage of animals lost due to a lack of or improper plumbing screening... SCREEN yours.


Iodine, alkalinity, biomineral content... are as important to Anemones as they are to stony, soft corals and other Cnidarians. Again, "Reef" circumstances are required to keep a BTA.

Both foods derived from photosynthesis and augmented physical feeding with meaty foods are necessary for this species. If your animal is or becomes bleached to a degree, ancillary feeding will become even more important. I suggest meaty foods, no bigger than the anemones mouth 2 ? 3 times a week, less if the food items are large. The best are fish based (Silversides of appropriate size are excellent, as are various kinds of shrimps, defrosted/frozen cube-foods, planktonic organisms that can be gently directly baster-placed...), and always of marine origin. Tongs can be used to place food items directly onto the open anemone's tentacles.

Some folks endorse the occasional to regular use/soaking of such foods in a vitamin and HUFA prep. like Selcon. This is not a bad idea.

And a note re post feeding behavior. It is not unusual for a just-fed, digesting BTA to "hunker down", shrink in size, pull it's tentacular disk inward and stay this way sometimes for a few days... Do be on the lookout for egested waste packets... and remove these with a net or siphon.


The vast majority (90 some percent) of anemone losses period are iatrogenic... caused by aquarists. In order of likely preponderance these are due to improper placement... Being put in with other too-noxious well-established Cnidarians ("corals", other anemones...), in inappropriate physical settings (too small, new/unstable, too little light), damaged specimens (too bleached, torn, starved...), poor maintenance (not using pre-mixed, adjusted water... powerhead disasters...), damage from other livestock (beaten by large hosting Clowns, eaten by predators, poked by Urchins...) and starvation (wrong foods, too large or small)... and NOT pathogenic disease.

Some symptoms of poor health in anemones include an open, droopy mouth, staying closed all the time, and turning to goo. Bleaching... turning more to completely white is a sign of diminishing health... the loss of endo-symbiotic algae that produce food and oxygen, aiding in the reduction of waste and CO2... Many factors can bring about this condition; heat-stress, poor lighting or photo-shock... The cause here could appear to be "nothing", but I would "step up" the feeding of the one specimen... try three times a week... for a while... And re-direct some/more circulation (likely via a powerhead, submersible pump) toward its general direction.

If your anemone, BTA or otherwise exhibits signs of poor health, what can you do? Remedy the root cause/s of the trouble... Provide better circumstances, remove obnoxious influences/animals, feed it better... Very possibly move it to another system, or return it or give it to someone who knows how, cares enough, has the proper set-up to care for it. Doing "nothing" is not an option... Often these animals outright dissolve... fouling the system, possibly taking most of your other livestock with them...

Avoidance of health issues is of course the better route to go... (rather than the too-late lack of health business emphasize in human health care in the West), with good initial-health acquisition of specimens, long/slow drip acclimation to appropriate quarters, maintenance and placement with suitable tankmate species.


Like all anemones, Entacmaea reproduces both sexually and asexually. The Bubble Tip is the only purposely stocked Actinarian to regularly produce and release gametes in captivity. This generally occurs during April and May between 0700 and 0900 AM a few days after a full moon. Hobbyists have been fortunate enough to observe/record not only the wispy release of sperm, but also planulae, greenish spheroid particle-young given off through the tentacles of females (Entacmaea appears to be dioecious, from the Greek meaning "two houses"... i.e. separately sexed). Females are known to also supply the initial zooxanthellae to their planulae offspring, thus helping to ensure their survival post settling.

Should your specimen/s release sperm into your closed system, you are advised to execute a large water change, clean your skimmer thoroughly (including the contact chamber) and utilized chemical filtration, to reduce the likelihood of fouling from this biomass. Continue water testing, mixing and storing of new water... and if need be, move all livestock to other established quarters.

Clones and asexual fragmentation of different degrees can result in the replication of many individuals from one. This can be a natural event, w/ no input from the hobbyist themself... derived from either too much stress, or propitious circumstances. Or, can be done more directly by cutting through a healthy, large, well-adjusted specimen... Through the mouth with a sharp implement (a razor or such)... up to about four pieces per episode, depending on the size of the donor.


Of the large anemone species offered in the trade/hobby of aquaristics, Entacmaea quadricolor is doubtless the best choice for a majority of applications. This being stated, these are not easy animals to maintain; requiring a well-established tank with "reef system" water quality and conditions, bright light of good spectral mix, and purposeful feeding. If you are so inclined to keeping an anemone, the BTA is one you should consider... particularly an asexually captive-produced clone individual... These are the very best in terms of capacity for survival under captive conditions.

If it is your intent to stock other anemones with your BTA or other Classes, Orders of Cnidarians, you are advised to start off with small colonies that are well-spaced, and place your anemone/s about last in an order of "likeliness to sting and chemically outcompete" one another. Even then, success is not guaranteed, and like "the price of freedom" (eternal vigilance), you must keep a ready eye for trouble in the growth and movement of your livestock en toto.

Given an initially healthy specimen, provision of basic space, a dearth of competing stinging-celled life too near or well-established, reef quality light, water and some feeding, Entacmaea quadricolors are simplicity to keep long term. Learn first, gather the necessary gear, and start your search for the perfect Anemone.

Bibliography/Further Reading:

www.karensroseanemones. net


Fautin, Daphne G. 2006. Hexacorallians of the World. http://geoportal.kgs.ku.edu/hexacoral/anemone2/index.cfm


Delbeek, Charles J. 2000. Tips on the changing shape of bulb-tipped anemone tentacles. AFM 6/00.

Delbeek, Charles J. 2002. The Effects of Lighting on Bulb-tip Development in the Bulb Tentacle Anemone, Entacmaea quadricolor (R?pell and Leukart, 1828), with Additional Observations on Sexual Reproduction in E. quadricolor and Stichodactyla gigantea (Forssk?, 1775). www.advancedaquarist.com/issues/nov2002/feature.htm

Fatherree, James. 2002. Keeping Sea Anemones. What you need to know. TFH 12/02

Fautin, Daphne G. & Gerald R. Allen. 1992, revised ed. 1997. Anemone Fishes and Their Host Sea Anemones. Western Australian Museum. 160 pp.

Fenner, Robert. 1992. Anemones in captive systems. FAMA 10/92

Karli, Scott W. 2003. Sea Anemones. FAMA 1/03.

Quattromani, Mark. 2002. Recent experiences with bubble tip anemones. FAMA 9.02.

Scheimer, Gregory. 1999. The spectacular rose anemone. Aquarium Frontiers 8.98

Shimek, Ronald L. 2002. Host Anemones. Responsible care will ensure their survival. AFM 10/03

Shimek, Ronald L. 2003. Anemone troubleshooting; With no defined life span, anemones may last indefinitely- but only if given proper care by an aquarist who researches their needs and meets their care requirements. AFM 10/03

Shimek, Ronald L. 2004. Are any Anemones right for beginners? In a stable tank, a couple species might work. AFM 3/04

Toonen, Rob. 2001. Invert Insights (column) Re: Anemones, Clownfish symbionts. TFH 9/01.

Toonen, Rob. 2003. Ask the Reefer (column). Gen. disc. re Anemones in captivity. TFH 3/03.

Wilkerson, Joyce. Anemone Survey Results: http://trickstr.tripod.com/survey_r.htm

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