It’s taken quite a while and there have been quite a lot of decisions to make. Before those decisions could be made research has been needed which probably meant the purchase of a good hobby book which in turn threw up a lot of questions. Thank goodness for the internet, a massive resource for information.

The decision on whether it will be a reef or fish only system has been made as well – of course it has, how else would the decisions on some of the equipment be made such as lights? So there the aquarium sits, full of seawater, all equipment running. The biological filter has been started and tests indicate all is ready. Seawater testing must continue through the stocking period and beyond of course. The new aquarist is nearly overcome by the desire to obtain livestock. Hold on a little longer though, the whole point of the system is to see healthy marine life so let’s not make a mistake with it.

Correct stocking means slow stocking with the correct species and this has to include consideration for further stocking later which means the first fish need to be compatible. There are fish available that are suitable for beginners and will not cause undue problems in the future. They are generally hardy and will forgive some novice errors which are often to do with seawater quality.

What if the system is to include a reef? The same thing applies: the corals need to be compatible and not a negative for the future and also be hardy (in marine terms). Though it is not absolutely necessary, it’s best to place corals in first and allow them to settle for a while so that they have the best quality seawater without the contaminating influence of fish. In addition corals usually arrive on a rock and this rock has to be fitted into the reef. This could raise the need to move or even remove rocks and new fish would be further stressed by this action. There are corals that are suitable for the beginner and could very well be enough for the future as they display beauty and interest together and individually. On the basis that corals are strictly best in first what is available?

The best corals to consider are those that are generally termed as ‘soft’. These corals come in various forms and there are many types. They provide a lovely reef scene and many sway in the seawater currents and make a lovely picture. The size of the aquarium needs to be considered to ensure individual coral types are suitable and also how many different types are required. Corals have a low impact on seawater quality, far less than fish, so that is one potential problem less. They should be firmly placed so they don’t fall later and have plenty of room for expansion. Corals should not be in direct line with a powerhead output. Some of the corals mentioned can be trimmed (‘fragged’) if they become too large, producing a new coral.

The first coral type is the finger coral (properly known as Sinularia sp and Lobophytum sp). As the name suggests they usually have a main stem attached to a rock with branches above which in turn carry smaller branches which hold the polyps. This is not always the case though, some are low level. One of these low level types is Sinularia dura which is possibly the hardiest of all but still lovely.

The toadstool corals (properly called Sarcophyton sp) have a thick stalk crowned by a flat head covered in extended polyps. They are quite unique in appearance and interesting to include.

Mushroom corals (properly known as Rhodactis sp and Discosoma sp) are a little similar to the toadstools but much lower. They are attached to rockwork by a short stalk and have a circular head. The head is usually of a rough appearance but not always. They usually form groups.

Button polyps (properly known as Zoanthus sp) are a grouping of polyps that appear similar to flowers in a vase. The heads are much smaller than the previous corals. They can spread and are usually constrained by the size of the rock(s) they can colonise. They are an excellent addition to a reef.

That’s a good start for corals so what about fish? They need to be compatible with corals and each other. Before a few fish species are considered let’s look at damsel fish. These are small, active, hardy and colourful. Some, even occasional dealers, still suggest them to ‘run in’ a new aquarium – this is wrong, maturation fluid should be used if required. Very important, damsel fish are generally territorial and aggressive. If they are placed in an aquarium first they will see the aquarium as their territory and could harass or attack later additions even those bigger than themselves. This could lead to the later fish being afraid to come for food resulting in poor health or death. So avoid damsel fish. If one must be had, introduce it to the aquarium last so that other fish are settled and ensure the other fish are sturdy and not easily picked on.

The first fish in this short starter list is the firefish (properly known as Nemateleotris sp). At first sight this fish species appears delicate but they are reasonably hardy and are best kept as a pair. They could grow to about 3”. Probably the best known firefish is Nemateleotris magnifica.

Another interestingly shaped and coloured fish is the bicolour blenny (properly called Ecsenius bicolor). This can also grow to about 3”. It moves from rock to rock and mainly stays in view, and could stop at a particular point for a while.

Now for the gorgeous royal gramma ( properly called Gramma loreto). This fish is a little larger and could grow to near 4”. It is beautifully coloured and a definite plus.

A fish that most would recognise is the so called common clown (properly called Amphiprion ocellaris). These could grow to about 3”. This clownfish bears the colours that signal ‘marine’, it is very attractive. Two could be kept. These fish are being widely commercially and home bred. It’s reported that the aquarium bred ones are more hardy than the reef caught ones, so it’s a very good idea to obtain the aquarium bred type. On the wild reefs clownfish live with anemones but this should not be attempted by the beginner. Keeping an anemone is not as easy as might be thought as experience is required. Common clownfish – particularly the aquarium bred ones – should be quite happy without an anemone.

If the aquarium is ready for stocking that is all is operational and the biological filtration is ready, the suggested corals and fish (or some of them depending on the size of the aquarium) should give a colourful and interesting foundation. They are reasonably hardy and are able – within reason! – to tolerate small errors beginners are likely to make. If the aquarium is big enough further fish and/or corals can eventually be added after research has confirmed that they are fully compatible with existing stock.

There’s something missing from this text – pictures. If the aquarist types the proper name into a search engine then a whole host of choices will appear, including pictures and care.

If the marine environment is of high quality then the occupants should do well. This includes the growth of corals which of course is good. However, this in itself can demand attention from the aquarist.

Some soft branching corals can show very significant growth.This could interfere with seawater flow and light availability – other corals could suffer because of it. A large branch over a smallish coral, throwing it into shade, could mean problems for that coral if the aquarist let things be.

So what can be done? It’s a little worrying when the question of cutting a coral arises and the thought ‘What if?’ comes to mind. The fact is that provided the environment is good corals repond well to trimming. The trimming shouldn’t be too severe of course and thought needs to be given to where and how. The where is easy, it’s the offending branch. The how is also easy, just some care is required.

All that is required in the way of equipment is a pair of quite long and definitely sharp scissors and a bowl to put the cut off coral in. A sharp knife of good length could also be used but scissors tend to permit more accuracy generally.

It’s not time for cutting just yet. First, the cut point should be made where the coral will not be left looking out of balance, that is, it should still look normal when the branch is removed. Usually the cut is made near to the main stem and a very small distance away from it.

Once the cut point has been decided and before the coral shrinks because of interference from the aquarist, the size of the cut off branch should be noted. Is there anywhere in the aquarium that it could be relocated? If there is then it can be securely placed between rocks. If not, then the plastic bowl will hold the piece until it can be transported to the dealers (speak to them first) or passed on to another aquarist. Before being transported in a plastic bag the cut off coral can be placed in seawater in the bowl and the bowl floated in the aquarium to maintain temperature.

The time has come for the cut to be made. Before approaching the coral the aquarist should note the angle the scissors will need to be at. Hands into the aquarium and with the scissors placed as required a single cut right across the base of the the branch should be made – do not open and shut the scissors as would be done when cutting a length of cloth, what is needed is a straight neat cut without any hacking. The branch should come away completely. Sometimes the branch is still fixed to the stem by a shred of coral – cut this also in one movement. The cut branch should never be pulled off by shearing any attachment by force.

The coral will of course react, quite understandably really! It will shrink and go into ‘sulk’ mode. It could also eject some milky substance into the seawater, this is a result of deflation and usually not a concern. The coral will remain closed up for a day or so but will inflate again. The coral should be watched for any sign of rot around the cutting site, this is unlikely if the job has been neatly done. If any rot does occur then it should be removed with about 1/4″ of the cut into healthy coral. For cuts of this type a very sharp knife is generally best.

The photo at the head of this text shows a coral two days after being trimmed. In the photo below the branch on the left of the coral is re-growth from a similar trimming operation which occurred about five months earlier.

Generally speaking corals have a high capacity to re-grow. The re-growth is likely to be different from the original, and where one branch has been removed for example two could re-grow, each of a smaller diameter or just one again. Corals can be trimmed time and again and provided the trimming is not too severe there will usually not be a problem.

Trimming corals has the advantage that additional corals are being produced for use by the aquarist, other aquarists or for the dealer. This is good for the hobby and the reefs. An aquarist who designs a reef carefully could fully populate it over time by using additional corals, although this is not so good an option from the point of view of captive reef variety.

Maintaining an established reef is simple overall - provide a high quality environment, properly populate and take necessary actions following observation, such as the one described here.

There are three types of marine aquarium and these are fish only, fish and corals (mixed reef) and corals only. If the aquarist has decided to keep corals only then there aren’t any questions to answer. The same obviously goes for a fish only system.

However, what if the aquarist goes for what is probably the most popular system, the mixed reef? What are the problems that could arise as far as the corals are concerned?

Generally speaking corals are more sensitive to poor seawater quality than fish meaning that the presence of fish is a negative from the start. Why should this be so?

Fish are generally the heaviest feeders in the aquarium and the larger the worse. Food and the end products of it cause seawater quality to deteriorate, for example the production of nitrate and the introduction of phosphate. The more fish the more pollutants. Poor seawater quality is combatted by routine seawater changes and good feeding discipline. Clearly, the aquarium should not be overstocked.

So all that needs to be done then is carry out routine seawater changes? The answer to this is yes of course, with a few more provisions. The guideline amount of seawater to be changed in the first months of the life of the system is 10% of the net gallonage (including any sump). The aquarist needs to carry out tests on a routine basis and keep a record of the results. There are several tests that are normally used for seawater testing, but the ones here are particularly nitrate and also phosphate. As already said nitrate is the end product of the decomposition of excess food and other organics and phosphate is mainly introduced with food.

Nitrate is a very useful indicator of seawater quality (but not the only one of course).Over a period of time the aquarist who has kept a note of test results should see a trend which will indicate the deterioration rate of the seawater (sometimes nitrate doesn’t appear or disappears after initial maturation). This trend will indicate to the aquarist the need or not to increase the amount of seawater routinely changed. If the nitrate continues to increase check the dry salt mix though nowadays this should not be the problem. It is also worth checking for nitrate content in the water being used to make the salt mix. 

If excessive phosphate is detected then again the dry salt should be checked though as said is not likely to be a problem. A check of the water used for the mix should be made. Phosphate is more likely to appear in a system containing fish.

So an aquarist with a corals only system is likely to find, all things being equal, that a seawater change of 10% is adequate. If there isn’t any indication of nitrate then it is worthwhile continuing with a 10% seawater change as this ‘freshens’ the seawater and adds some trace elements that are lost because of protein skimming as an example. Experienced aquarists could decide to reduce the seawater change amount a little, but routine seawater changes should not be abandoned. Of course, dependant on the type of corals kept other supplementation such as calcium could be needed.

There are few aquarists who are satisfied with just corals. For a start, the scene seems to appear more natural with fish present. However, once fish are present then seawater deterioration increases. How should the aquarist proceed?

In an ideal world the corals should be introduced first, permitting them to settle and also permitting the aquarist to be happy with the reef  layout. This procedure is not essential but is a good practice. After a few months when the corals are clearly healthy and settled the question of fish can be considered.

In a fish only system the stocking can be to the limit of the net gallonage (excluding any sump). This is not so in a mixed reef system. To assist with the maintenance of high quality seawater the stocking levels are restricted.

Again there is a ‘best practice’. There isn’t a requirement to have lots of fish as there already is a lovely and developing coral scene. Also the fish need to be fully compatible with the corals, it wouldn’t be pleasing if coral was a tasty lunch. They should not be too large, permitting them to move among the corals easily, small fish are usually the best and there are some really beautiful ones. The aquarist should add  two small fish first (hopefully after they have been quarantined). Once a minimum period of a month has passed all should be well with the fish settled into their new home. The aquarist should consider if his/her creation is sufficient, that is, is there a need for more fish? It could be that there isn’t. If there is, then add two more fish and again leave a month and re-consider. To repeat, there isn’t any need to have lots of fish. The movement of a few fish complement the already lovely reef scene. Under no circumstances should the maximum stocking guidelines be exceeded – and remember that fish grow. The stocking guideline for a mixed reef is a maximum 1″ (circa 2.5cm), excluding the tail, to 6 gallons of seawater, excluding the seawater in the sump. 

Using the above stocking method the aquarist is protecting the all important seawater quality by reducing the pollutants that are introduced into it. This in turn should reduce the size of the required routine seawater changes provided the fish numbers have been minimized. The result should be a mixed reef to be proud of.

Besides bubble coral other common names are octocoral, bladder and grape coral. The proper name is Plerogyra sinuosa. It is not difficult to obtain and if seen in a store is easily recognized, as the name implies it is covered in inflated fairly large bubbles (or bladders or grapes). On sight the coral appears to be delicate but they are fairly tough. Nevertheless, handling and placement need some care.

The coral is often roundish with the bubbles emerging from the upper surfaces. The bubbles are inflated and it is reported could expand up to around 500%, leaving the wall of the bubble the thickness of one zooxanthellae.* Quite thin then!

The coral is expanded during daylight hours. At night the bubbles retract and tentacles appear which are used for feeding.

As already said some care is needed with handling and placement. Though the coral is tougher than it looks, handling should be minimized (as with all corals) and the chosen place on the reef should not be close to sharp pointed or edged rocks in case of damage to the coral, the bubbles could rub against the adjacent rocks in seawater currents. Ensure the coral is secure; a fall could damage it and lead to infection. The coral can be placed nearly anywhere on the reef as it does not require powerful lighting, however strong lighting does not appear to cause any trouble once acclimatized. A newly purchased coral should not be immediately exposed to very powerful light as they may have been used to low light in the wild and the stronger light could shock and damage it, so it is best to keep overly powerful light off the coral anyway. Reef quality lighting (spectrum) is required because of the zooxanthellae, it could be possible that the size of the bubbles is controlled by it, the lower the lighting strength the larger the bubbles to ensure there is enough light. What does mainly limit potential position is the strength of the seawater current, this should not be strong or the bubbles will be too violently shaken or will not expand to their fullest. The best seawater current strength is low to moderate. A final point on placement – it is capable of extending quite potent sweeper tentacles which could attack and damage adjacent corals, so maintain a good space between it and any neighbours. This is good practice with corals anyway.

The coral is not overly striking in colour as some are; though the colours vary they are not bright. This is not to say the coral is not attractive, it certainly is. It could be green, ivory, cream or white and some have bubbles that have clear colourless narrow stripes on them.

This coral does not present any feeding problems; there isn’t any need for suspension feeding. A small piece of de-frosted fish or similar can be gently placed on the coral and will be taken in, what could be easier? The coral is easy to feed and sometimes is overfed because of it. One feeding every other day, or longer intervals according to experience should suffice.

The bubble coral should not present any difficulty even to a moderately experienced aquarist, provided that seawater quality is high and attention is given to proper placement on the reef with regard to seawater current strength, security and lighting. The coral is yet another variation that Mother Nature has evolved which can be an attractive and interesting addition to a reef aquarium.

(*Reference: Aquarium Corals. Eric H. Borneman)

The first link is to photographs, click on it to enlarge. The second is a short video.

http://www.poppe-images.com/images/search_results.php?keyword_mh=Plerogyra+sinuosa&x=53&y=8

These corals are attractive in general, but the main attraction is the pulsing of the polyps, they rhythmically open and close. There has been considerable argument over why this should be, and the most obvious answer held sway for quite a long time. This answer was that by pulsing the coral drew suspended food particles to it so that they could be captured. Watching the coral’s action this seems reasonable. However, the latest thinking that I am aware of is that the pulsing is to obtain more oxygen, in other words a breathing movement, more seawater is passed across the polyps thus more oxygen becomes available. Some aquarists automatically dismiss this as it is compared to the similarity of human breathing. Several authorities support the ‘breathing’ reason. I am not able to state the scientifically proven correct answer. Perhaps there will be scientific enquiry into the coral and facts will emerge. If they already have I’d be pleased to know.

Anyway, the attractive coral is upgraded to fascinating by the pulsing of the polyps. Sometimes in an aquarium the polyps cease to pulse, or only pulse weakly. Again, at least to me a definitive answer as to why this should be is not known. There has been argument, some saying that in an aquarium iodine is likely to be lacking and this causes it. However, some have measured for iodine and found it present at a correct level yet there isn’t any pulsing. Others have suggested that the aquarium may have saturation levels of oxygen and there isn’t a need for pulsing. The latter one could have some merit if the coral’s reason for pulsing is related to oxygen. (The respiration reason for pulsing is cited in some respected books.) Another reason suggested is that there is excessive nitrate in the seawater. If the polyps reduce their pulsing action nitrate is easily checked for, but unfortunately there doesn’t seem to have been any feedback from aquarists on this point (to my knowledge).  Again perhaps science will come to our aid one day. The good thing is that even if the pulsing does reduce or cease, the coral does not seem to decline and remains attractive.

Pulse coral is the major common name, Xenia elongata or Xenia umbellata the proper ones (two separate types). There are other pulsing corals. They are suitable of course for a reef aquarium. The coral has a thick ‘trunk’ which leads to many ‘branches’, which in turn split off and lead to many polyps. The coral attaches to rock. It is important that the coral receives sufficient light as the flesh contains zooxanthellae which supply the majority of the coral’s food requirements. Ensure the light reaching the coral is direct and bright. Seawater movement should be moderate. Excessive seawater movement will have a detrimental effect.

The pulse corals are not difficult to keep and do well in an aquarium, provided of course that seawater quality is high and lighting is adequate. Placement seems to be one key to success (as with many other types), this could be a little problematic as placing the coral higher up the reef should provide sufficient light but perhaps too much seawater movement. When placed, watch the coral, does it expand properly and does the expanded coral look comfortable, that is not banging about in the current? It is easy to see when things are fine.

Having a pulse coral in the aquarium certainly adds to interest to state the least. If the pulsing action reduces or ceases, first be sure there isn’t excessive seawater movement. Then check for nitrate, if the level has increased reduce it by increasing the amount of routine seawater changes, at least temporarily. Investigate the reason for the nitrate increase and correct it. (The guideline for nitrate in a reef aquarium is 10ppm or less.) As a final check, all else having proved not to be the reason, check the seawater oxygen level, perhaps the seawater is carrying the maximum? Overall though, this coral should give little trouble.

The link below will give further information and photographs, just scroll down the page, lower down is a picture of a coral in action.

http://reefkeeping.com/issues/2004-02/ac/feature/index.php

They are given their common name because, obviously enough, the branches of the coral generally resemble the horns of a stag, though the branches vary considerably. There are other common names such as tabletop coral and cat’s paw coral (some have flat tops as does a table so there are also those that resemble a cat’s paw), but these names do not fit so well overall and are not as widely used. The proper name for the type being looked at here is Acropora. I can immediately find 47 types of Acropora in the references available to me and I’m sure there are many more, one suggests a total of 300 or more. They each have their own proper name under the heading of Acropora, hence the general look only.

As a hard coral they belong in a reef aquarium of course. The aquarium should have powerful lighting such as metal halides, probably best supplemented by, say, two actinic fluorescent tubes. High seawater quality is a must, and the calcium and alkalinity levels need to be monitored. Acropora corals demand calcium and the amount of usage can be surprising in a well stocked reef, so supplementation from commercial sources could be possible in a small system, but it is likely to be too expensive and cumbersome for a medium or large one. In the latter the usual practice is to install a calcium reactor. The calcium level is best kept between 420ppm (parts per million) and 450ppm, though some aquarists elevate this to around 480ppm. Such a high level is not really necessary as long as the suggested lower levels are maintained. Alkalinity in an aquarium is best if it is higher than natural seawater levels. Alkalinity resists the tendency for pH to drop because of acidic action, in other words it acts as a buffer. The best level in an aquarium is between 3.5 meq/L and 4.5 meq/L. 4.0 meq/L seems reasonable. Some fluctuation doesn’t matter provided it is fairly minor. (NB. meq/L can be converted to dKH if desired, multiply by 2.8.)

So the corals need high quality seawater with appropriate calcium content and alkalinity, plus correct lighting. The lighting could have an effect on the coral’s colour; the colour could change from that when purchased. This change is usually because the symbiotic algae, the zooxanthellae, are reacting to the lighting available.

Another requirement is seawater movement. The majority of the corals are used to high seawater movement and this should be duplicated as far as possible. A minimum flow rate suggested by the guideline is twenty times the display aquarium net gallonage per hour, which is double that suggested for a soft coral display. This flow can be provided in the usual ways such as powerheads. It is worth considering the high output types with wide delivery nozzles as opposed to narrow nozzle types, particularly the ones that can be controlled and made to alternate seawater output level. Whatever type is chosen, they need to be positioned so that a jet of seawater is not directed straight at a coral, though this isn’t as important with wide nozzle types.

Not all Acropora corals require high seawater movement, though as said the majority available to the marine aquarist do. One way of generally judging seawater flow requirements is to consider the colouration, if it is bright then it is likely that intense light is required which brings the coral closer to the surface where strong movement prevails. Another indicator is the length and shape of the branches, if they are short and club like they resist high seawater movement better; longer and more slender branches are more likely to break. Generally, if there are any doubts place them in an area of high movement and, as with all introductions to the captive reef, observe to ensure all is well.

Acropora corals could worry the aquarist when they are first placed in the aquarium. Even though the conditions for them are excellent, they could take a while to settle before commencing to grow. Once they have settled however, and provided conditions are maintained, they shouldn’t be a problem.

When placing the corals allow room for growth, if conditions are good they are fast growers, some more than others and this growth can be such that the reef becomes overcrowded fairly quickly. Having said that, the corals are excellent for ‘fragging’, a term used in the marine hobby for culturing additional corals from a mother colony. This practice is excellent for the hobby and for the wild reef: for the hobby ‘fragged’ corals appear to be more resilient than those from the wild, for the wild reef if corals are ‘fragged’ not so many are required to be collected. Therefore if the captive reef does start to become overcrowded ‘fragging’ is a definite action to consider, and it isn’t difficult.

Though it varies, the branches of the corals are fairly fragile and snap easily, more so towards the tips. Therefore care is required when they are handled. Sometimes they can be positioned so that rocks hold them until they establish themselves, but it is probably better to secure them with some aquarium epoxy putty, which sets very quickly.

Acropora come in all sorts of shapes and colours. Most seem to be branched and resemble a terrestrial bush to some extent, with generally uniform branches sprouting out and upwards. These branches could, as said, be thick, short and club like or longer, dividing and slender. Others grow to a flat top shape thus the name ‘table coral’. The pink and blue of some types are, to me anyway, particularly lovely, though the colours vary with many others.

These corals are more demanding than most, but not all, of the soft corals and the aquarist has to be sure that he/she is willing to provide the ‘extras’ required – seawater should be top notch anyway, with very low nitrate and phosphate. The extras are controlled levels of calcium and alkalinity, high seawater movement and sufficiently powerful lighting. A stable environment is required as generally the corals tolerate changes poorly.

The link gives many pictures of the corals. Click on a picture to enlarge.

http://www.poppe-images.com/images/search_results.php?keyword_mh=Acropora&x=40&y=9

If the aquarist can provide the environment for the corals, the reward is a colourful and very ‘reefy’ display. A successful hard coral reef display is regarded by some as the pinnacle of achievement.

Zoanthids belong in the reef aquarium and must be known to just about every marine aquarist. They are commonly known as button polyps.

These polyps could appear in ones or twos but more likely are displayed as what could be termed polyp boulders. These are of varying sizes but the ones often sold in local fish shops could be in the region of 4 to 8 inches in diameter. The whole surface apart from the underneath is usually densely packed with polyps.

‘Zoanthid’ covers a wide variety of proper names, the most common one found in local fish shops being, arguably, zoanthus. This name in itself covers numbers of individual proper names.

The polyps come in a variety of colours such as light and dark brown, light medium and dark green, bright green, with lesser numbers pale blue, bright blue, and red. It is possible for a group of polyps to be of different colours, this is usually because different types are intermixed. Some individual polyps themselves could be one colour, or have the disc one colour and the tentacles another. Some types have a stripe from the centre of the polyp to the outer edge.

Button polyps are known as a good starter for beginners. In marine terms generally they are hardy and should survive some mistakes a beginner could make. Use of the word ‘hardy’ does not mean that high quality seawater is not required, it is.

It has already been mentioned that their home should be a reef aquarium; this is because they require the correct lighting. Button polyps have a lot of zooxanthellae (single celled algae within the flesh) upon which they are highly dependent. It is possible that when a colony has been in an aquarium for a while the polyp colour changes to a degree; this is because of zooxanthellae adjustment to the available light. In an aquarium with powerful lighting the button polyp colony is often perfectly happy very low down, which is very helpful to the aquarist. After they have been placed, wherever that is in the aquarium, as with other corals they need to be observed as time passes to ensure they are thriving.

In addition to correct lighting, the colony could require medium or fast seawater flow. They are usually tolerant of medium or even slow flow whatever the type, though an indicator of likely flow requirement can perhaps be determined by the length of the polyp stalk and also the length of the tentacles.

Button polyps do not normally require special feeding as, as said, they have dense populations of zooxanthellae. In fact some types ignore the usual floating feeds intended for corals or fish anyway. Others will capture for example brine shrimp which have been put into the aquarium for the benefit of fish and also smaller foods, if used, intended for corals.

The link shows some general pictures of button polyps. Click on them to enlarge. The photograph shows a colony of polyps in my reef, these were grown from four polyps which were transplanted into suitable holes (for some reason they came loose from the mother colony, is this a way of spreading perhaps?).

http://www.poppe-images.com/images/search_results.php?keyword_mh=zoanthidae&x=53&y=10

A general caution should be given here. The Zoanthus type above does not, as far as I am aware, fall into this caution category but as the type is so similar to the types that do, Palythoa and Protopalythoa, the caution is relevant.

Palythoa and Protopalythoa types contain a neuromuscular toxin which is called palytoxin. The toxin is contained in the mucus. The toxin is potent and could be fatal to humans. Tribesmen in the relevant areas used to put the toxin on their spearheads in order to paralyze animals and enemies.*

Though it is very unusual to hear of any problems encountered by aquarists, it is clearly wise to be aware of the potential of the toxin and, particularly if there are cuts and/or abrasions on the hands, to take reasonable precautions such as wearing rubber protective gloves.

(* Reference: Eric H. Borneman. Aquarium Corals)

Probably the most used common name is the one quoted but they are also regularly called colt corals. As said in other texts, common names are notoriously poor for identification and the proper name is Cladiella sp. There could be around 40 types under this heading. Here is one of them:

http://www.biopix.com/Photo.asp?PhotoId=40720&Photo=Colt-Coral,-Finger-Leather-Coral-(Cladiella-sp.)

Cladiella species are generally more similar to the usual mental image of a coral in that they are branched. The branches are usually fairly thick and quite short protruding from a short stalk which itself is thick. If the coral is touched it will usually be slimy as they have a heavy mucus coating.

The coral is, as corals go, undemanding. There isn’t a requirement for high powered lighting, an array of T5 tubes should suffice. Seawater flow is not particularly critical either, as fairly strong to moderate should be fine.

Coral cutting or ‘fragging’ is becoming more and more popular and quite rightly so. Cladiella sp. corals are good for cutting and should not present any problems. A clean cut to remove an appropriate ‘branch’ should be made and the branch gently fastened to a rock. It should attach and become a new coral to give to another aquarist or exchange at the LFS.

Just because the coral is hardy does not mean that seawater quality should not be at its highest as any coral, hardy or more difficult, will respond best in a quality environment. If kept by an experienced aquarist there should never be a problem, if kept by an inexperienced aquarist this type coral should survive most of the problems that beginners could generate.

To properly identify the coral it should be called Alcyonium species. There are perhaps around 30 types under the Alcyonium banner. They are soft corals.

When they are extended they can be feathery or with more clearly individual polyps. They are branched and the branches could be thick or fairly slim. Again, some of the species are encrusting and are not so clearly branched.  The branches extend from a main stalk which is usually thick and fairly squat. If the coral is touched it will feel slimy because of its heavy mucus coat. Some soft corals could grow to large proportions in the aquarium, but this species is sometimes smaller. It is possible to obtain the coral in brown, green, red, orange and yellow, though if the aquarist is after a particular colour a search and wait could be needed.

Here’s a link, but remember there are different shapes and types, this is one of them:

http://www.biopix.dk/Species.asp?Language=la&Searchtext=Alcyonium%20digitatum&Catagory=LavereDyr

As with other corals under the ‘leather’ heading, this coral is hardy and suited to all aquarists. They can be showy and make a great display along with other types that have been described in other texts.

The coral should adapt to aquarium lighting well, and doesn’t demand powerful lighting such as metal halides. An array of T5 fluorescent tubes should suffice. Seawater flow is not critical either; a moderate to fairly strong one is acceptable. As with any soft coral, the flow should not be strong enough to obviously cause the coral ‘discomfort’, or the coral will not extend properly – resistance to flow rate depends to an extent on coral shape.

Alcyonium corals are easy to propagate or ‘frag’ to use the aquarist’s phraseology. When the removed part is fastened carefully to a rock it should soon attach and begin to grow.

This coral is hardy and suited to the beginner as it will resist most common beginner’s mistakes. At the same time it is an attractive addition to the aquarium.

My current soft coral reef has been running for well over six years now and there are corals that have been present from the start. One type is the toadstool coral (Sarcophyton sp.) which has and is spreading with new babies popping up quite regularly and the major corals needing regular cutting.

Another coral is the cabbage, sometimes called the flat leather or flexible leather coral, though obtaining the desired coral by using one of these common names is very hit and miss. The proper name is Sinularia dura.

http://www.biopix.com/Photo.asp?PhotoId=40732&Photo=Cabbage-Leather-Coral-(Sinularia-dura)

The coral is made up of flexible ‘leaves’, and when these leaves are expanded they display attractive markings and deeply serrated edges. The form of the ‘leaves’ depends on the seawater flow, I had to cut the original colony in my reef and the ones in a strong flow are generally flat and undulating as described, but the ones in a low flow are more fluted and upright.

The coral is very forgiving as far as light intensity and seawater flow are concerned. The lights do not have to be powerful metal halide bulbs; they could be fluorescent T5’s. Seawater flow can be moderate to fairly strong; if the flow is very weak the expansion of the coral is much reduced. The coral is therefore a reasonable candidate for placing lower down on the reef with moderate flow.

If the coral is happy the aquarist can expect the colony to increase in size though this is not always rapid. A group of expanded and overlapping ‘leaves’ is really attractive and also different from branched or domed corals.

Attractive as they are there is one more immensely important attribute as far as beginners are concerned – they are very hardy. I think (without substantiating facts but going on my own experiences) that Sinularia dura must be one of the hardiest corals available. The often made mistakes of a beginner affecting seawater quality should not of course occur, but they should be tolerated.