Anemones in the Reef

Roni Talukdar

Hello all. Recently I've noticed a somewhat disturbing trend. Every "feature" aquarium seems to be dominated by SPS corals, and anemones have started to receive a bad rap.They've become to commonplace for experts and "too hard" for conscientious beginners. Personally, the anemone-anemonefish symbiosis was what drew me into the hobby in the beginning, and I've always found space in my systems for 1-2 anemones.

With this in end, I'd like to dispel some myths people have about anemone husbandry and give some guidelines for successful care. I will start by giving some general information and then go onto a more specialized discussion of individual species. If you have any questions, feel free to ask.

Anemones are classified in phylum Cnidaria, which includes all that have nematocysts (stinging cells used for defense, capturing food, etc.). Today's talk will center on the anemonefish host anemones, which are concentrated in family Actiniidae and Stichodacylidae.

Anemones can basically be thought of as water-filled tissue sacs with tentacles on top and a flat base on bottom.

The cylindrical main body is basically at the mercy of the exterior environment, which is one of the reasons that anemones suffer more from osmotic stresses than fish do.

The tentacles typically form circular arrays emanating from the mouth, which is the anemone's only opening.

Typically the foot (base) of the anemone serves as an attachment point for the anemone and a means of movement when a new situation is desired

General husbandry of anemones is generally an area that novice reefkeepers tend to underestimate. Due to their low price and immense popularity, anemones are typically sold as the first "non-fish."

Many times the system these animals are put into are very insufficient for proper care, and people notice that "my anemone just got smaller and smaller till one day it disappeared."

Anemones are not necessarily hard but do have some requirements that must be met.

First, one needs a system with fairly good light intensity. I've found that anemones thrive in setups with MH and have seen good success with power compacts, VHO, and even NO fluorescent system.The dependence on light varies from anemone to anemone but a good minimum to shoot for is about 2-3 watts/gallon.

Water current is sometimes overlooked and usually a medium-strong intermittent current is appreciated.

An important consideration with anemones is their tendency to wander.

This means that occasionally they will sting corals or harm themselves by getting stuck in the intake of a powerhead. An easy way to prevent this (and also to protect small fish from a grisly fate) is to place a bioball in the intake (finally, a use for bioballs again :)

Other methods include building an eggcrate cage, not using in-tank powerheads (Geminis, Lgs), or even using a sponge (though that's a pain to maintain).

Nutrients are not as big a concern with anemones. Nitrate levels below 10 ppm are fine (though you might experience algae). Basically, if you have a system that is appropriate for soft and hard corals, it is usually sufficient for anemones.

The subject of feeding anemones is a highly debated one. I usually don't feed my anemones because I find they grow too large with constant feeding. Because the host species are 99% photosynthetic (or at least their symbiotic zooxanthellae are), I think most anemones under good conditions can go without feeding. If you choose to feed, however, make sure to only feed in small amounts and you can feed as often as the anemone eats without spitting up. Never "force-feed" your anemone and if the majority of the food is spit up after a few hours, don't continue to trying to feed.

Now I'll move on to a discussion of the various species. If you have any questions about what I've said so far, please feel free to ask though I'm not sure if I get to answer yet :)

Our discussion will begin with Entacmaea quadricolor, the bubble-tip anemone. Generally the base is brown-red and the tentacles vary between green, brown, pink (the Rose morph), and maroon. These anemones are also characterized by swollen tips that tend to appear when the anemone has a symbiot.

These are by far the easiest of the host anemones, tolerating poor water conditions and light much better than others.

They can be kept with the minimum 2-3 W/gal and also tend to ship well.

It was a bubble-tip anemone which got me into the hobby. As a testament to the strength of this anemone, I'll quickly relate my experience.

When I first saw this anemone, it was almost white and very small, dwarfed by the maroon clown which lived in it. It had been in that system for 6 years to that point.

When I acquired the system, I moved the anemone into my 58 gallon. At this point, the anemone was in such bad shape that you could see through it to the substrate below.

I didn't harbor any large hopes for the successful recovery of the anemone but decided to give it a chance.

Over the next 3 weeks, it slowly recovered its brown coloration (due to zooxanthellae) and grew from a quarter size to a decent 3" in diameter.

I had that anemone for about a year and then gave it to another beginning aquarist. At that point it had growth to 6" in diameter with no direct feeding.

This anemone is also one of the easiest host anemones to propagate in captivity. I have personally had one anemone divide into two and have heard several reports of other occurrences.

The most notable anemonefish that inhabit this anemone are the maroon, skunk, clarkii, two-stripe, and tomato clowns.

In addition, there have been scattered reports of ocellaris clowns accepted E. quadricolor as a host though IMO the clowns never look as nice as when they are in a natural host.

The next anemone has received a fairly undeserved bad rap among aquarists, IMO. The sebae anemone is the common name for Heteractis malu and Heteractis crispa though H. crispa is the one more frequently associated with the common name and the anemone that we will consider here.

H. crispa can be distinguished by its long, stingy tentacles and its flattened form (basically, since the trunk is buried, you only see a disk with tentacles sticking out).

The most common color is brown though pink, purple,

and even blue forms are seen occasionally<P>

This brings up the main problem with these

anemones. Frequently yellow or bright purple specimens

show up in dealer systems<P>

These anemones are injected with food coloring or

some other synthetic dye and are not normally this

color. Almost invariably these specimens die and the

few that survive generally turn white, and then slowly

brown up (in effect, you lose your "colored" sebae :(<P>

Additionally white sebaes show up, but these are

simply anemones that have ejected zooxanthellae and are

deprived of their major nutrition source.<P>

Selection of a suitable specimen is the key to

keeping these anemones alive<P>

Once a healthy specimen is chosen, these anemones

tend to be hardy and long-lived<P>

Additionally, the sebae anemone has higher light

requirements than the bubble-tip (about 4-5 w/gal min).<P>

They are host to two-stripe, clarkii, skunk, and

true percula clowns among others. Since ocellaris/percu

la clowns are favorites of many, this is very important

since sebaes are easier than the other host anemones for

ocellaris or percula clowns.<P>

The next anemone to be considered is the

Macrodactyla doreensis (long-tentacled anemone). I

personally don't have much experience with this anemone

but from what I gather, it is also a fairly easy anemone

to keep.<P>

There are a multitude of color combinations with

brown, green, blue, and purple being common. This

anemone likes to bury its base in the sand and requires

strong lighting (4-5 W/gal min). The two most notable

clownfish symbiots are the clarkii and skunk clowns<P>

The most spectacular of all anemones, IMO, is the

ritteri anemone (Heteractis magnifica).<P>

The "ritteri" common name comes from the old

scientific name, Radianthus ritteri and specimens with

the scientific name Radianthus show up frequently<P>

Ritteris can be problematic in captivity. First,

they usually come in huge (>12 inches in diameter) which

is a problem for people with smaller systems.<P>

Additionally, they tend to wander in many people's

tanks.<P>

These considerations are important but overshadowed

by the positive aspects of this anemone<P>

It is beautiful, with a full trunk that comes in

red, purple, and brown and tentacles that vary between

yellow, pink, brown, green, and even more exotic

combinations.<P>

The ritteri is also accepted by a large group of

clowns, including the skunk, clarkii, percula,

occellaris, two-stripe, and nigripes clowns.<P>

Selection of a healthy specimen is very important

with this anemone. Look for a specimen with no tears in

its foot and a mouth that is not gaping<P>

Also, unless you have a large system, select for the

smallest specimen possible because the anemone will

expand further under good lighting.<P>

When you transfer the anemone to your system, make

sure to slowly acclimate and then place the anemone on

its own rock separate from your main rockwork.<P>

Ritteris tend to wander to the highest point in a

system to maximize the amount of current and light they

receive. This can lead to stung corals and a vexed

aquarist :)<P>

Fortunately for us, however, anemones lack a brain

:)<P>

They will usually not go down a rock to go up, which

means that as long as they think that the rock they're

on is the highest point, they won't leave it<P>

If they sense another rock formation, however,

they will move to it so make sure the tentacles don't

touch your main rockwork.<P>

I've also found that feeding a silverside or other

appropriately sized food as soon as the anemone will

accept food tends to reduce wandering<P>

I have only kept or seen these anemones kept in

systems where MH was the primary light source so I can't

really comment on any other lighting<P>

The last two anemones I'll discuss today are the two

carpets, Stichodactyla gigantea (giant carpet) and

Stichodactyla haddoni (saddle carpet).<P>

Though these are in the same genus, no two anemones

could be farther apart as far as ease of husbandry.

<roni> The saddle carpet ranks up with the bubble and sebae

anemones as far as ease.<P>

They typically are less colorful with brown and

green being the predominant colors. Usually saddle

carpets also have white stripes that emanate radially

from the mouth.<P>

Similarly to the sebae and long-tentacled anemones,

saddle carpets prefer to bury their feet in sand. With

good water motion and strong lighting, these anemones

are very easy to keep<P>

Two problems, however, are that they usually come in

huge (>16") and are voracious fish eaters (they don't

"hunt" fish but any fish unfortunate enough to stumble

into them dies a grisly death).<P>

The clarkii and sebae clowns are the predominant

symbiots though ocellaris clowns will sometimes also go

in.<P>

OTOH, the giant carpet is probably the hardest host

anemone to keep. Coming in incredible colors (blue,

green, pink, purple, and brown), they rival (some think

beat) ritteris for sheer beauty<P>

Additionally, almost every clownfish accepts them

(excluding the maroon, tomato, and a few others).<P>

Unfortunately, they are prone to bacterial

infections and really don't ship well<P>

I personally would recommend avoiding mail-ordering

these and checking the foot very, very carefully for

damage as well as doing the normal checks before buying<P>

Additionally, make sure to place in an area with

strong current and very strong light<P>

I personally have tried two blue carpets and both

have succumbed to bacterial infections.<P>

Delbeek and Sprung offer an antibiotic treatment in

TRA vol.2 but most people are unequipped to perform this

type of action.<P>

If you have a quarantine system that has strong

lighting, good water motion, and the other necessary

attributes for keeping giant carpets, then you can try

the treatment. Otherwise, it will most likely not be

successful<P>

The good news about these anemone is that if they

survive the first month, they tend to survive

indefinitely. There have even been reports of spawning

and fission (reproduction) in captivity.<P>

That basically is the end of my talk. In

conclusion, if one maintains a proper reef environment

and takes the individual anemone's needs into

consideration, anemones are fairly easy (with the

exception of the giant carpet).<P>

I would personally recommend people consider keeping

an anemone because IMO, the symbiotic relationship is

one that can't be topped and also the one thing in your

tank that even the casual observer will be entranced by

:)<P>

Q: <I>I was told by John Tullock that the proper way

to aclimate an anemone is to put into a tuperware type

bowl with no water, let float in the tank unti it has

expelled all the water, dumping water as you go, is this

correct or is there a better way?</I><P>

I don't like that because it place undue stress on

the anemone. SInce there is no water to help support

the anemone, tissue damage can occur very easily.<BR>

A better way would be to drip acclimate and then

transfer to the main system<BR>

I personally only temp acclimate all my anemones

that are bought locally and only drip acclimate with

mail order<BR>

The reason many anemones suffer in shipping, IMO, is

that they are basically shipped dry. without a

backbone, these anemones depend on water to support them

to an extent.<P>

Q: <I>Can they be enticed to stay where placed?</I><P>

I've had little problem with keeping anemones put.

I usually try to place them in a area with good current

and lighting and then feed.<BR>

With the bubble-tip, the carpet, sebae, and

long-tentacled, it's best to give them something to hide

their foot in.<BR>

Like maybe a small depression or a little circle of

rocks. they never move IME<BR>

With ritteris, use the separate rock trick. It has

only failed once and this was with a ritteri I could

swear was trying to piss me off :)<P>

Q: <I>What anemone is the natural host for the

ocellaris clown?</I><P>

There are three primary: the giant carpet, the

ritteri, and the saddle carpet.<BR>

Also, sometimes the bubble-tip when the clown is

desperate enough<P>

Q: <I>Would you ever mix an anemone in with an

established reef tank?</I><P>

Would and have. Usually its best to add them first

because of the tendency to wander but I recently placed

a ritteri (4 inches in diameter) on a rock in my 100

gallon with no problems.<P>

Q: <I>Is a ritteri's sting strong enough to harm the

other tank inhabitants, notably tangs, domino's and

blennies?</I><P>

Yep. IME, the only fish that a Ritteri will

actually catch, however, are fish that are already hurt.

My yellow tang got stung by a ritteri once and quickly

learned not to explore that particular area again :)<P>

Q: <I>Is a 55 gallon tank big enough for a large

ritteris and can more than 3 percula clowns live in one?</I><P>

Depends on how you qualify large. I've seen 2 meter

specimens in pictures and have seen 18" specimens in

captivity. However, I had an 8" specimen in a 58 with 2

clowns with no problem.<BR>

When you keep more than 2 clowns, the weakest always

looks much worse than the others. However, an 8"

ritteri would be fine for 3 or maybe even 4-5 occellaris<P>

Q: <I>What is the best choice anemone for a percula

true or occellaris clownfish?</I><P>

True perculas accept the giant carpet, Ritteri and

sebae. The sebae is the easiest though I'd personally

go with a ritteri. Occellaris accept the saddle carpet,

ritteri, and giant carpet with the saddle carpet being

easiest<BR>

Also, they sometimes accept bubble-tip anemones.<P>

Q: <I>"how long CAN they live? (both in captivity and

naturally)?</I><P>

Very long. 100 years isn't an impossibility. The

oldest I've heard of in captivity was only about 10-15

years old but the hobby is young so...<BR>

Most anemones don't die of old age per say but

rather some natural or manmade phenomenon<BR>

For example, if clownfish are taken away from a

giant carpet, a 200 year old carpet becomes

butterflyfish food in a matter of days :(<P>

Q: <I>If you see your anemone shrinking/getting

smaller what steps can you take to try and save her/him?</I><P>

Try feeding. Additionally, make sure you have

enough light and current. Check for tears or basterial

infection. Also check for potential pests: crabs,

butterflies, etc.<BR>

Usually when the anemone has started to shrink, it's

a downhill battle from there<BR>

They take a long time to show nutrition deficiencies

and usually don't accept food at that point. Sometimes,

however, they will shrink somewhat but be healthy. It's

hard to tell but usually shrinking is bad.<P>

Q: <I>If you see a tear, or other infection, what can

you do as far as antibiotics?</I><P>

Delbeek and Sprung recommend 5-10 ppm of

streptomycin or neomycin<BR>

A better chance might be with chloramphenicol<BR>

However, it's hard to treat unless you have a good

quarantine system. Do not ever treat your display

unless you want a nice little system crash.<BR>

Craig Bingman told me that when he used

chloramphenicol on his system to stop RTN, he had the

worst 3-4 days in his life. The system suffered hard

but somehow pulled through. He is a chemist, however,

and the tank was already going down.<P>

Q: <I>What about colour fading eg pink to white?</I><P>

Usually either low light or too high light. Make

sure to gradually acclimate to MH as you would with most

corals.<BR>

place in a shaded region or cut photoperiod down to

1 hour the first day and gradually increase by an hour

at a time, watching the anemone for reactions.<BR> A good routine is 1 hour first day, increasing by 2 hours every three days.<P>

Q: <I>When talking to Gerry Allen at a local club

meeting he said it was thought that anemone's may live

for many thousands of years. Taking this into

consideration should we be keeping them in our tanks,

especially the larger species ?</I><P>

That's a tough question. I avoid large anemones for

several reason, that being one of them.<BR>

E. quadricolor can be progagated and if you get

small specimens of the ritteri, they are usually new

"buds"<BR>

It's really a matter of how much is harvested. I

feel that if you can provide a good environment, then

its okay, but if you continually kill anemones, then you

need to stop until you know what's going on.<BR>

Q: <I>Can high temp cause bleaching?</I><P>

Yes. I was helping someone recently and their

ritteri mysteriously died. We went through a myriad of

obscure reasons and then he checked his temp.<BR>

His thermometer had broken and the real temp was

about 90!!!<BR>

Anemones also tend to ship very poorly during

periods of high temp.<BR>

After acclimating to the system, however, I've found

anemones to be fairly temp tolerant provided there is

good oxygenation, as most corals are.<BR>

82-83 is probably the highest I'd want to go,

however.<P>

Q: <I>Any normal reef tank inhabitants to be weary of

getting (might eat or disturb an anemone)?</I><P>

Anything that is weak or stupid enough to get stung

twice :(<BR>

Carpets have a terrible sting and they will catch

fish the first time, however.<BR>

The key is to make a little ring of rocks around the

carpet and make sure to not have any currents blowing

directly at the carpet.<BR>

Bubble-tip, sebae, and the long-tentacled shouldn't

be a problem at all.<P>