Trimming A Branching Soft Coral
January 7, 2011
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.
The Feather Duster Worm
June 10, 2009
Reef aquariums could be home to many life forms. One of these is the obvious, fish, in many aquariums these are small and inoffensive, and in bigger systems larger varieties could find a place. The major consideration with fish is that they are reef friendly.
Quite apart from fish there are many varieties of life. As the systems in this case are reefs the next is corals, both hard and soft. The corals are really what make the display a reef, the rocks may be ‘live’ and there may be fish flitting about, but it is the corals that make the picture.
Seen less are sponges as these are considered difficult by many aquarists and therefore they are not always attempted. It is reported that many sponges are not as difficult to keep as imagined, but their demise is often because of poor collection when damage is caused or when the sponge is allowed to come into contact with air. Algae can be another sponge enemy.
A spectacular life form that could be kept in a reef aquarium is a worm. Not just a worm though, this one is a real show off. The worm lives in a tube and is considered very attractive because of the head of feathery tentacles that appear. They are expanded into the seawater in order to trap food. The expanded tentacles do look similar to the old fashioned dust mop or feather duster that tackled cobwebs etc in days of old.
The worm is understandably commonly called the feather duster worm, or sometimes the peacock worm. The proper name for arguably the best is Sabellastarte magnifica. Feather dusters are common in warm seas and are usually easily obtained from local fish shops.
The tube extends from the rubble or rocks but all of it is not usually in sight. The tube could be up to 6 inches in length and the extended tentacle crown could be between 2 and 3 inches in diameter. The worm slowly extends the tentacles often stopping during the process and if everything seems fine the tentacles are completely extended. As they fully emerge they open up into the distinctive head.
The worm doesn’t appreciate strong seawater currents because of the head. If the current is too strong the worm could withdraw back into the tube. It is best to locate the tube in an area where only slight to moderate currents exist.
If a worm is seen to be hanging listlessly out of the tube it is likely to be dying.
When the tube with the worm within is first introduced to the aquarium the proper acclimatization technique should be applied. During this period it is best to ensure the tube is not exposed to air at all. Once the worm is ready for transfer the tube can be placed securely between rocks being careful not to crush it, when the worm is active it should adjust any faulty anchorage. Place the worm as said in an area of light to moderate currents, and lower down on the reef particularly if the lighting is powerful. The worm hasn’t any need for lighting as corals have. A worm that is positioned in bright light could be slow to appear until it is accustomed to it. It is reported that the worms do not like high temperatures – a top temperature of 76 deg F is sometimes quoted, though I kept one at 77 deg F for a long time.
Sometimes an aquarist can be alarmed as the worm drops its crown of tentacles. This could have been caused by stress produced by too high a temperature, excessive and sudden seawater currents, too large a change in seawater specific gravity or harassment. The first three are easily avoided. Harassment is avoided by ensuring that only suitable tank mates are present. Many common reef fish, such as damsels, dwarf angels etc could nibble at the worm’s tentacles. There are more that could cause a problem. Fish such as the copper-band butterfly (Chelmon rostratus) should be avoided. The best fish to keep with the tubeworm are small dottybacks, fairy baslets, gobies, blennies and the like. The worm can disappear into its tube at a terrific speed thus avoiding trouble, but repeated occurrences of this lead to stress. Once any problem has been corrected leave the worm alone. It could take a longish period to re-appear, and they are capable of re-growing a crown.
The tube worm feeds on very small plankton in the wild. In the aquarium once the worm has been given time to settle and is displaying its full crown of tentacles it can be target fed. Using a small syringe-like device, a small amount of fine filter-feeder food can be ejected ‘upstream’ and allowed to drift over the tentacles. If necessary seawater movement pumps can be temporarily turned off though this should not be necessary. It is best not to squirt the food straight at the tentacles or it is likely the worm will withdraw them believing danger is present. In an aquarium where there are many other filter feeders the food shouldn’t go to waste and the seawater quality shouldn’t be affected.
Looking at the suggested fish companions for the worm it seems the ideal home would be a nano aquarium. In these small systems it is usual to keep smaller inoffensive fish. The worm can successfully be kept in a large system subject to the other inhabitants, which means a lot of discipline could need to be applied by the aquarist.
The feather duster worm is a different and very interesting addition to a captive reef. Below is a short video.
Zoanthids
May 15, 2009
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)
Nudibranchs
April 18, 2009
The wild reefs are home to some pretty weird creatures and some of these creatures can be really attractive. The nudibranchs fall into this category, to me anyway.
On the wild reef many creatures have a niche for the supply of food. Some fish will just cruise along devouring their type of food, the usual example given are surgeons which often move in shoals eating algae. There’s a fish that farms algae and will aggressively defend the area from interlopers such as surgeons, though faced with a large shoal it has little chance. Some life forms are predators, others omnivorous. Whatever food is available, there’s something there to eat it, which is Nature’s balance.
Nudibranchs are the same; they have a food niche too. The food supply for all nudibranchs is not the same, most will predate on a particular type. Unfortunately for the reef aquarist, this food is often a type of coral.
Many aquarists check corals and coral rocks when they are purchased to try to ensure, as far as possible, that there aren’t any unwanted organisms. What are usually in mind are those weeds of the reef aquarium, aiptasia, and similar growths. It is possible that a nudibranch could be found.
I recall that many years ago I obtained a soft coral from my LFS, complete with rock. A general check was made of the coral and rock but nothing was seen to make me suspicious. A while later, maybe a couple of days to a week, I noticed the coral seemed to be unhappy and reducing in size. What made me examine it again along with its rock I don’t know but this is what I did. Underneath the rock in a crevice were two yellow nudibranchs. I removed them from the aquarium and placed them into a bowl which was floated in the aquarium. Attempts to identify the type of nudibranch failed. I took them to the LFS but they died.
The two nudibranchs I found will have been predators of that particular coral, which is why they were imported with it. If they had been left the coral would quite probably have been completely eaten, or been so badly mauled that it would have died. At that point it would have been death for the nudibranchs as there wasn’t any other coral of the type is the aquarium. That is why they died at the LFS, there wasn’t any food for them.
It is understandable therefore why nudibranchs are not a common feature of reef aquariums. There are very few aquarists who would be prepared to feed corals to them, no matter how beautiful the creature might be.
Many of these creatures have colouration which reasonably matches their prey, a defence against being predated upon themselves and making them more difficult to spot. Others have bright colours to warn that they are distasteful or dangerous to eat.
It isn’t just corals that could be the prey item for nudibranchs; some eat worms, fish eggs, mollusks etc. It is clear that all of them present a very difficult maintenance problem for the aquarist.
Nudibranchs (pronounced ‘nude – i – branks’ by the way) are really fascinating and strange creatures possessing different beautiful colouration. It is a great pity that they are not suitable for the captive reef. If they were, I for one would keep a couple.
The link provides just a few pictures of these creatures, there are many more types. Click on individual pictures to enlarge them.
http://www.poppe-images.com/images/search_results.php?keyword_mh=nudibranch&x=67&y=9
The Blue Coral
March 11, 2009
This coral falls into the ‘soft coral’ group, an octocoral, but it is a little strange for that grouping. This is because it is a reef building coral.
The coral is also a little misleading to the eye with its common name. It would be very understandable if an aquarist with a particular desire for a blue coral was looking for a coral that was actually blue! It isn’t. The external colour is a green tinged grey or brown and the polyps off-white. If the underside of the attached coral could be seen, then the blue would be also. If the skeleton is broken then again the blue would be seen. In other words the blue is internal. Another way of identifying this apparently hard coral is to note that there aren’t any corallites on the coral surface. Corallites are those circular areas that usually occur on a hard coral’s surface that contain the polyp.
Break an octocoral, surely they’re soft? This one isn’t, it could be mistaken for a hard coral. The link gives some pictures.
http://www.poppe-images.com/images/search_results.php?keyword_mh=Heliopora+coerulea&x=73&y=8
The common name as shown is blue coral, and they are also sometimes called the ridge coral. The proper name is Heliopora coerulea.
The coral is best placed in strong seawater movement and also under strong lighting, though it should be happy with medium movement and light as it is reasonably tolerant. The coral is also reasonably hardy, a word that pleases aquarists. It also has quite a fast growth rate, and could be ‘fragged’ should the aquarist wish.
The coral is common in the wild and there isn’t any current threat to it from collection.
This coral is a good addition to a well maintained reef aquarium and shouldn’t pose any particular problems. The coral is reported* to prefer warmer temperatures, between 80 and 84 deg F, so the aquarist who has obtained one could need to increase the seawater temperature slowly.
(*Reference: Aquarium Corals. Eric H. Borneman)
Coral Calcification
February 17, 2009
There are many marine aquarists successfully keeping corals nowadays and a good thing it is for protection of the reefs because of commercial interest, a pool of home grown or ‘fragged’ corals and enjoyment.
Those aquarists, particularly with hard corals, will be adding calcium probably along with other supplements. This will often be done in a smaller aquarium by using a commercially prepared additive and with a larger aquarium by employing a calcium reactor.
So it is clear that aquarists know that calcium is an essential and also know that it must be available in sufficient quantity at all times. This is for the benefit of shrimps and snails and the like but also mainly for corals. The aquarist faithfully does a calcium test and uses the additive or replenishes the calcium reactor with media from time to time. Some aquarists could answer the question ‘What is calcium added for?’ with ‘It allows corals to grow’. That’s correct.
A hard coral when dead is usually white. The colour that is seen on a living coral is caused by zooxanthellae, the single celled algae that dwell in the flesh of the coral. It is for these algae that lighting of the correct spectrum and power is provided. The algae provide a high percentage of food to the coral but are also involved in calcification.
As with most other things, looked at in depth it is all quite complicated. It could well be interesting to those with a bent for science but for most of us the basics are fine. There isn’t a need for complications on aquaristsonline.com; the point is to keep it straightforward. Therefore, a link is provided below that gives a basic run-through of corals in the aquarium including calcification:
http://fishinsects.suite101.com/article.cfm/keeping_coral_alive
For those who would like to delve deeper the link below should be of interest:
http://www.advancedaquarist.com/issues/apr2002/chem.htm
Brain Corals
February 13, 2009
Brain corals are often available in local fish shops and are common in home reef aquariums. Other common names, though not as popular as the title, that they are known by are pineapple coral, star coral and moon coral. The proper overall name is Favia. It is not endangered in the wild.
Favia are very common in the wild and look like a boulder which could be small are in older ones very large. The upper surface of the boulder is covered in round flower-like stone patterns. When the polyps expand they cover the surface of the boulder completely. The link below shows some, clicking on a picture enlarges it:
http://www.poppe-images.com/images/search_results.php?keyword_mh=Favia&x=70&y=7
The polyps swell in the daylight period and cover the boulder completely, and at night the feeding tentacles appear. The colour of the coral could be yellow, brown, or green but it is likely that green ones are the most available. They are attractive in a similar way to button polyps. Green ones under actinic blue lighting look terrific.
The corals are fairly tolerant of lighting conditions and seawater conditions too and so find favour with many aquarists. Hardy is the word normally used. Though they are tolerant they of course do best in high quality seawater. Lighting could be a metal halide system, though it is possible that if the coral were to be placed too close it could burn. The problem is easily avoided because of the coral’s lighting tolerance – it can be carefully placed on the substrata, provided light reaches it directly. Fluorescent lighting such as T5’s should also be sufficient, provided the aquarium is not too deep. Seawater movement is also well tolerated; though very strong currents should be avoided the usual circulation in a reef aquarium shouldn’t be a problem.
Some Favia types can use long sweeper tentacles during the night which could damage nearby corals. When first placed in the aquarium and after a period of settling in, the aquarist should observe if this is happening and move the coral if interference with other corals occurs.
Though this coral is hardy, it is reported* that Favia can sometimes suffer from jelly infections and coral recession. High seawater quality and movement should help prevent this, along with careful handling when the coral is first introduced.
It is a good idea to occasionally feed the coral, which is easily accomplished. At night permit a small amount of de-frozen brine shrimp to drift across the coral. Using a pipette type instrument is good for this; one possibility is a normal kitchen baster.
The Favia coral should do well in an SPS (small polyp stony) reef though within reason it could be tried elsewhere as they are hardy. The SPS are normally higher on the reef than the Favia which as said could be on the substrata. Having a coral of this type in such a reef adds variety of shape and assists with the population of the lower areas.
(*Reference: Aquarium Corals. Eric H. Borneman)
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