Soft Corals: A Primer
Soft Corals: A Primer
Soft Corals are a family that lack a defined calcium carbonate skeleton, maintaining their form primarily with calcium 'splinters' in their flesh.
Many, many of these corals are easily kept by beginners, but some are far from it. Most are adaptable to different levels of lighting and current, though in this list I'll give you the ideal.
Keep in mind that a handful of soft corals, when properly kept, can quite quickly grow to a very large size.
Now the species. You'll forgive me for starting with my favorite.
Called Gold Crowned Toadstool in shops is Sarcophyton alcyondae.
From a heavy trunk with a rounded cap, long, flowing bronzy gold polyps tipped in bright light gold emerge in the mornings. Over time, that cap will grow into a wide folded form. This is one soft coral suitable for competent newer reef keepers.
Like all commonly available Toadstool Corals, they can and will grow quite large; several feet tall. Though just semi-aggressive, their sheer size can shade other photosynthetic corals to their ruin.
Take great care in moving a Toadstool coral into its final position, since its frags are fragile. Site it in the lower region of your reef, so it'll have plenty of room to grow. Obviously a quite large and tall aquarium is necessary if one wishes to keep this or any other of the Sarcophyton species.
The Gold Crowned Toadstool can adapt to lower medium to high lighting; take care moving its frag into higher light, since it can be damaged. This toadstool coral prefers a low medium, pulsing, chaotic current. Like most soft corals, once a year or so the Gold Crowned Toadstool will regenerate. It will refuse to open for several days, then will shed its outer layer. A keeper must be on hand to remove the remains of that discarded layer.
One can feed their toadstool coral, since it'll enhance its health and appearance. A phytoplankton drip will generate the Rotifers this coral will gladly eat, and a defrosted Mysis shrimp placed gently among the center of the polyps late in the day will be consumed. However, hand feeding should be done no more than twice a week, while a phytoplankton drip can be continual.
Keep in mind that all Sarcophyton species corals can produce a toxic substance to poison any nearby corals, so either space other corals far away, or place your Toadstool Coral 'downstream'. Aggressive protein skimming is vital if one wishes to try their hand at one of these easily-kept soft corals.
Commonly available and another coral suitable for nascent keepers is Devil's Hand, Lobophytum pauciflorum
From a flat, palm-like surface, long, finger-like projections radiate, making the coral appear to be an open hand. A scattering of small, white tufted polyps are scattered about; most are on the 'fingers'. Originally Devil's Hand Coral was available in shades of brown mustard, but several other colors can be found these days.
The presence of the polyps during the day means this coral benefits from regular feeding. A phytoplankton drip will generate a healthy colony of Rotifers that this coral eats, and soon it'll add more and more fingers as it grows. Devil's Hand tops out at about dinner-plate size in the average aquarium, sometimes larger, very well kept and fed.
This coral prefers medium light, so if one uses metal halide-based, or one of the LED fixtures now in vogue, its frag should be placed in the lower third of the aquarium. Current should be moderate, and pulsing and chaotic, since Devil's Hand occurs in the turbulent fore reef in nature.
Devil's Hand also goes through periods of inactivity, refusing to open for some days, and sheds a skin. This usually occurs once a year, sooner if the coral is well fed.
There are several other members of Lobophytum available, all under common names describing finger color and/or shape.
Dark and light yellow is Alcyonium fulvum, the Yellow Encrusting soft coral.
Though in shops its frag is less than impressive as a single arm of this coral, it grows beautifully properly kept. Best placed on the substrate, this coral will steadily encrust it, producing finger-like stubby arms covered with thousands of tiny, bright yellow, corallites.
Unlike the previous two species Yellow Encrusting and others of its genus feel slimy rather than leathery. That's because they collect algae and debris in a thin mucus layer, and when A. fulvum shrinks at night, it voids that layer and generates another. That means protein skimming should be large and capable if one wishes to try this easily kept coral.
One should be aware when first introduced this coral will produce much mucus, which can damage corals downstream. A keeper should site the coral where it is going to stay, since the excess mucus will be produced almost whenever you move it.
One can feed their Yellow Encrusting coral as it will enhance it's growth and appearance. A live phytoplankton drip maintained constantly will duplicate the turbid, micro-organism rich, waters it comes from. Though it'll stay small if you don't feed it, if you do, it'll grow into a real showpiece as it grows and encrusts your substrate.
Though moderate light is fine, this coral can be placed higher in the tank, even in halide-based lighting, in a sandy spot. I wouldn't place it higher than half way, though.
It likes moderate, pulsing currents that are randomized, like by aiming outflows towards the glass or live rocks.
There are several other as yet unnamed by science members of the genus Alcyonium. They go by the common names of Chili, which is red, and some finger corals, which are either encrusting or has finger-like arms emanating from a short trunk.
In a well-established and stable tank, Yellow Encrusting is very hardy, thus is a good choice for a newer keeper.
Another easy-keeper is Colt Coral, Cladiella species.
Highly recommended for nascent keepers that have an established aquarium, Colt will grow well and rapidly. From a short common base, many arms grow in all sorts of directions as the coral makes sure each arm can receive light. The arms appear fluffy as this coral has thousands of very prominent corallites. It's available in shades of browns, grays and yellows.
Like the above, this coral produces a mucus layer. When first introduced it can exude a lot, and it can severely damage corals that are downstream of it. Thus, if a keeper plans on buying a frag of this coral, it should be one of the first soft corals in their tank. That allows it to settle down and become established.
The prominent coralites indicates this coral is an avid feeder, so for best health and form, establish a live phytoplankton drip to replicate the soup of micro-life like this species lives in nature.
The more light this coral gets the more compact and attractive it grows. Though it can be kept in lower light, in middle to high light it lives and grows best. Current should be moderate; not enough to move the arms, and pulsing and chaotic. Adaptable, it can grow in high to lower light, and low to medium current, as long as Colt is patiently moved there. That makes it ideal for newer keepers.
Like the above species, this coral shrinks at night to void wastes. Thus, protein skimming is highly recommended, and should be rated for at least twice your aquarium size.
Even more attractive and kept the same way is Purple Finger, Cladiella australiensis.
This import from the Solomon Islands and Jakarta grows into a gorgeous purple berry color, with thousands of small, bumpy corallites all over it. Though it can be kept precisely as the above species, Purple Finger instead grows into an encrusting form, with short, defined finger-like arms across its length. Thankfully it is available captive raised.
In the evenings this coral puts out olive green polyps. Avid feeding as described above will enhance the health, growth and appearance of this lovely, hardy coral.
One of my very favorite soft corals.
The sole non-photosynthetic soft coral in this list is also one of the most challenging to care for, are the Carnation Corals, Dendronephytha species. In a scale of 1 to 10, with ten being the most difficult to keep, the Carnation Corals are a 9.5.
Though in books and shops these corals look less than impressive, well kept and fed they can be perhaps the most beautiful of the soft corals.
Found on the back reef at depth where copious zooplankton continually comes up from below, Carnation can have translucent flesh where the calcium carbonate splinters can plainly be seen. A graceful base has flowing arms with off-branches and with fluffy red coralites. That describes mine.
If one wishes to keep one of these gorgeous soft corals, constant feeding is warranted. A live phytoplankton drip, established some months before trying a Carnation coral, is essential, since these corals need a continual flow of live microalgae. The drip must be maintained constantly, day and night. Also, enriched live baby brine shrimp should blown toward the coral (via turkey baster) every evening to trigger the feeding polyps of it. See my how to culture manual on enriching live baby brine shrimp.
For reasons I'm unaware of, Carnation usually fails when hair algae is in the tank.
No light is needed for these corals, so site it in a shaded area in your tank. Current should be medium, pulsing and turbulent. You want the current to carry micro foods through the coral's area in a pulsing, periodic flow.
Available in shops are usually D. rubeola or D. aurea. There are others in the Dendronephytha genus available that have yet to be named to science
Obviously, a deeply experienced and dedicated reef keeper who has a large, very well established reef aquarium, and is capable of maintaining the constant micro-food flow necessary, should attempt one or more of these beautiful corals. Stability of temperature and natural sea water levels must be constantly stable.
Properly kept, Dendronephytha, isn't terribly difficult to keep if fed correctly and kept in natural sea levels of minerals as close as possible to that of the coral reef. Stability of temperature is vitally important.
Another soft coral suitable for competent beginners is the extremely hardy Kenya Tree Coral, Capnella species.
From a smooth trunk sprouts long, flowing, highly branched, arms that are studded with polyps. Colors available are shades of brown, cream, green and blue. Often with a contrasting color on the polyps. In shops the frags don't look like much, but over time it can grow to be quite decorative.
The only caveat with this coral with this coral is it must be fed, since it relies a good deal less on its symbiotic algae in its flesh as other corals. A constant live phytoplankton drip established about a month prior to purchasing the frag will reward you with outstanding growth and health. Like most corals, Kenya Tree can live a very long time, many decades. It can cover an area of upwards of two feet with those flowing arms.
It likes moderate to high lighting; take great care moving the frag to the latter, since it can be damaged moving it too quickly into bright lighting. I kept it in the lower third of in my halide-based lighting. Light is less important to it than feeding, so a phytoplankton drip is the easiest, not to mention the cheapest, way to keep this coral fed.
You'll want a moderate, pulsing current that is randomized, like by pointing an outflow at a rock.
This is another soft coral prone to regenerating occasionally. It'll refuse to open for some days, then void its outer layer. Make sure you are on hand when it does that, so that discarded layer can be removed.
Kenya Tree is an easily kept coral, as long it is fed as I describe.
Another coral suitable for beginners are the Finger Corals, Sinularia species.
Arising from a thick base are branches that look rather like an antler form, since they have several off-branches. Contrasting colored coralites cover the branches. One of the easiest of the soft corals to keep, as Finger Corals grow rapidly in reasonable conditions. Those beginners competent in FOWLR or reef keeping should have little trouble keeping Finger Corals.
Finger does best in moderately bright light, and likes a pulsing, chaotic moderate current that slightly moves the branches. One should site the frag lower in the tank, then carefully move it to the mid-reef where the light and current are ideal. Best temperature is 77 degrees for Finger Corals.
You may see Finger listed as Colt in shops, but Finger has a heavier trunk and the branches aren't as fluffy as Colt. Finger grows into an antler form while Colt's branches are almost random.
Though not absolutely essential, one can feed Finger Corals. A phytoplankton drip maintained will help generate micro critters these corals eat. Alternately, enriched live baby brine shrimp can be added in the evenings, since Finger polyps can take those too.
There are many colors and forms of Finger Corals, usually sold describing color, like Green Finger, Mauve Finger. There are several different forms as well in the Sinularia genus, but in my opinion the antler form is the most attractive.
Next are the Pulsing Corals, Xenia species.
By pulsing I mean the stalked polyps open and close almost in unison. That aids in respiration and feeding, though the latter doesn't mean Xenia needs to be fed.
What they do need is a steady supply of the natural sea water trace element Iodine. That must be maintained at .06 ppm constantly to keep Xenia and its relatives from crashing. Sometimes crashing means finis, but often the coral will recover when Iodine returns to the natural level.
Usually occurring in a cream color, feathery polyps cap a long steam. They can emerge from a domed base or in a branched form. Xenia is very attractive and eye-catching properly kept.
What it likes is moderately bright light, so carefully move it's frag over time midway up your halide-lit reef. A brisk moderate current will help Xenia respire and void wastes, so make sure it's pulsing and chaotic.
When happy (well kept), Xenia can grow terrifically fast, and rapidly colonize live rock. Not aggressive, it can be damaged growing too close to aggressive corals.
Xenia should be the only soft coral in your tank, since it usually is inhibited and refuses to pulse when other soft coral species are present. Apparently they produce a substance that stunts Xenia.
As long as the Iodine trace element is steady and light and current are ideal, Xenia should grow very well for you, and it always enchants visitors seeing it pulse.
Similar to the above are the Anthelia corals.
Usually displaying longer feathery polyps than Xenia, Anthelia also grows into a more attractive form, with a long span of polyp-topped stalks issuing from a base. It also occurs in more colors than Xenia, since I've long had one that is powder blue in one of my reefs, one of the very few soft corals I keep these days.
Anthelia can pulse when it cares to. Also, it enjoys the phytoplankton drip I supply my reefs with, and is quite the showpiece.
Anthelia is quite easy to keep, though of course it needs the trace element Iodine steady for optimal health.
One of my long-time favorite soft corals.
Next are the Polyp corals, another family ideal for beginners.
There are the colonial Button Polyps of the Zoanthus genus, and the Sea Mats of Palythoa, in which the polyps emerge from a fibrous encrusting mat.
The polyp corals have short stalks topped by circular polyps edged with a ring of tentacles. If you can think of a color of Polyp Coral, there's probably one available in it, usually with contrasting colors in center of the polyps. Those from Australian waters are particularly vivid. The polyps can be small or large, depending on the specimen. The Polyp Corals are all in the Zoanthiniaria order, hence the common name Zoas for these corals.
One should be aware that both Button Polyps and Sea Mats contain palytoxin in their tissue, so I very highly recommend wearing aquatic gloves to handle them, since that toxin can make you very sick should you have a cut on your bare hand, and it can kill the very young and very old. Wash the gloves with a dilute bleach solution and rinse under warm water until the bleach smell is gone after handling the polyp corals. What's ironic is there are a couple species of sea slug that eat those corals, transferring palytoxin to them to reduce predation.
They like moderate light and medium, pulsing chaotic current. Given them, the polyp corals can really grow and encrust nearby live rock. Given a phytoplankton drip and they will explode in growth, and one may have to prune their polyp coral regularly to prevent it taking over the aquarium. The better quality and intensity of light the more colorful the polyp corals are.
If natural sea waters levels and temperature is steady, Polyp Corals should grow very, very well for you. Whenever anyone asks me for a coral to start with, I always point them toward Polyp Corals.
I highly recommend the Polyp corals to competent beginners.
Classically hydroid in shape are Yellow Polyps, Parazoanthus gracilus.
A colony-type soft coral, Yellow Polyps aren't connected to each other, but they do group closely together. As the common name describes, the coral has long, slightly translucent yellow slender stems capped by long, thin tentacles. Probably via chemical messenger, Yellow Polyps are always all out together, or retracted together, based on aquarium conditions and time of day. The better water quality and aquarium stability the more open Yellow Polyps are during the day.
They prefer moderate light and a lower medium current that gently moves the polyps.
This is one soft coral that enjoys a regular (weekly) feeding. Enriched baby brine shrimp gently blown towards the coral will be taken. Though it's not essential, Yellow Polyps can benefit from a phytoplankton drip, since it'll enhance the health and number of the polyps. Such feeding will also result in great growth, so you can easily frag this coral to share with friends or sell.
Kept properly Yellow Polyps are extremely hardy. An excellent beginner coral.
Our last soft corals are of the Clavularia genus.
Commonly available in the hobby are the Star Polyps and Clove Polyps.
Star Polyps emerge from a purplish, rubbery mat that are long and grass-like. They go under the common name as Daisy Polyps, and they are available in a multitude of colors. An encrusting coral, when it grows too far, the mat can be cut and tied to a small piece of live rock where it'll soon attach and encrust it.
Clove Polyps have thicker stalks capped by a wide feathery polyp making it look somewhat like an Anthelia. It retracts into a bumpy wine-colored mat in the evenings. Clove Polyps are quite popular these days, and are available in many different colors, usually with contrasting polyp centers.
Both types like a moderate light, so about a third the way up in a halide-lit reef. Current should be moderate, pulsing and randomized; not enough to disturb the polyps, but just enough that they very smoothly flow.
They can also benefit from feeding, A defrosted Mysis can once a week or so be placed gently among the polyps where it'll be consumed. A phytoplankton drip will enhance color, growth, and health.
Both types are suitable for competent beginners. On a scale of 1-10, they are a 1 - easiest.
Thus ends the soft coral primer. Questions are of course, welcome.
Last edited by Dave66; 03-10-2012 at 05:48 PM.
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