Things Change

Pretty obvious really! The weather is an example. But no, we’re concerned with marine aquariums of course.

In a fish only aquarium the changes are usually, strangely enough, to do with fish. New additions, growth, the cave/hole they live in and the like. In a reef system more changes are often noticeable.

On the wild reef changes occur slowly for the most part, though things could happen quickly. If a storm comes along then coral formation could change as corals are broken. Unfortunately change can also happen quickly (in terms of the life of the reef) caused by man-made pollution and interference. Normal reef changes are when one coral slowly dominates another in a long drawn out battle for space, or coral colonies spread over new areas.

So change is quite natural. In the aquarium changes could be unnatural, that is caused by the aquarist. An example is the cutting of corals because of growth. When corals grow they could shadow or at least reduce the light available for others and in addition the seawater flow could be altered, meaning that some corals do not receive the flow they require. So the aquarist cuts the corals to maintain the balance of light and/or flow. This is a quite drastic change that doesn’t occur in the wild of course. Overshadowing will occur to some extent though. Hopefully the aquarist having cut corals will ‘frag’ them so that additional good comes from the exercise.

Other changes can occur and this unfortunately includes coral failure. Nowadays with the greater amount of knowledge available failure in this area should be much reduced. However, failure can occur in more than the usual way, the usual way being that a coral is just not happy, closes and shrinks away quite rapidly.

In my soft coral reef there is a colony of green star polyps, which are sometimes called star polyps or daisy polyps. The proper name is Pachyclavularia purpurea (some call it Clavularia viridis but this is incorrect)*. Anyway, the thing is that this colony arrived six years ago on a rock which was completely covered. The rock would be generally about 6 inches across at the base and about 4 inches high. After a while the coral spread onto a neighbouring rock and completely covered that as well. There wasn’t anywhere else for it to go so it stopped spreading.

For a long while it just came out at ‘dawn’ and went in at ‘dusk’. It was perfectly healthy and also completely at home, happy with the lighting and seawater currents. It was attractive and added to the many colours of the display.

Eventually I noted that it was beginning to climb onto itself that is it had nowhere to go except to cover itself. So the mat was spreading and new polyps were opening on top of the original.

I was quite concerned about this as I thought first of all that the lower layer could lose adhesion – but it didn’t. The spread across a lower layer continued for a long while, years in fact and eventually the colony was higher than it had been originally because of the layering. I was pleased in a way as the shape of the colony had altered; it no longer followed the shape of the rock but had formed mounds and spires plus some flatter surfaces, making it more interesting.

This situation continued until I noticed that some of the colony, a small area only, didn’t have any extended polyps. Sometimes the colony had not expanded for a whole day or so on previous occasions, therefore I wasn’t concerned.

However, the polyp areas that failed to expand extended in area. Eventually I noticed a bare area of rock down near the base. This area extended until very nearly all of the rock was bare. Some of the remaining un-layered matt containing polyps was removed and placed elsewhere in the aquarium and this is opening normally, appearing to be beginning to form a new colony.

Apart from one area on the adjacent rock that was colonized there wasn’t anything left. The reduction and loss happened over about a period of two months, which isn’t very long.

It isn’t all bad news though. I’ve recently noticed that a few odd polyps have appeared on the rock and hopefully these will lead to a re-colonization. If this occurs then I’ll recover the original colony and have an additional transplanted one.

So why did this occur? All other corals are fine, expanded with proper polyp extension. It follows that seawater quality and lighting are also as they should be.

I reckon my original fear that the original matt could lose adhesion was not the reason for the die-back. Adhesion loss could of course have occurred but the colony remained in place.

It seems to me that as the colony for the most part actually disappeared then it must have ‘dissolved’, or rotted away. This could have started with the covered lower layers rotting, which would have caused the top layer to become affected.

What I have to do now is wait and continue observing the polyps that remain, both the two small colonies and the separate polyps. Hopefully the original colony will grow back to full size.

If full size is achieved then perhaps the colony will eventually begin to overgrow itself. This would presumably mean the colony will eventually fail again. The possible way out of this is to put a bare rock alongside the re-generated colony which can be grown over. This can be placed elsewhere in the reef or given away.

As in the wild changes occur with the captive reef. It all makes the hobby so interesting, don’t you think?

The photos (taken by me so not of professional standard!) show the area where the original colony existed alongside the rock that was colonized, where some of the coral remains. The other photo, taken closer in, shows the polyps that have appeared that give me hope that a new colony will re-generate.

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

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Conversions

Here are a few conversions which could be useful to someone, you never know. The ones shown are those that could be applicable to aquarists, maybe!

To find volume.

Multiply length by breadth by height. (If finding the water space volume of an aquarium it is more accurate to measure from the water level. It must also be remembered that volume will be taken up by rocks and sand.)
Cubic inches to cubic centimeters – multiply by 16.3871
Cubic feet to cubic meters – multiply by 0.0283
Cubic centimeters to cubic inches – multiply by 0.061
Cubic meters to cubic feet  multiply by 35.315

Converting Centigrade to Fahrenheit.

C                         F
24                        75.2
25                        77 (the temperature many aquarists use)
26                        78.8
27                        80.6

Length.

(10 millimeters = 1 centimeter)
(1 inch = 2.5 centimeters)
Inches to millimeters – multiply by 25.4
Feet to meters – multiply by 0.3048
Millimeters to inches – multiply by 0.0394
Meters to feet – multiply by 3.2808

Area.

To find area multiply length by width.
Square inches to square centimeters – multiply by 6.4516
Square feet to square meters – multiply by 0.0929
Square centimeters to square inches – multiply by 0.155
Square meters to square feet – multiply by 10.764

Capacity.

UK fluid ounces to liters – multiply by 0.0284
US fluid ounces to liters – multiply by 0.0296
UK pints to liters – multiply by 0.5682
US pints to liters – multiply by 0.4732
UK gallons to liters – multiply by 4.546
US gallons to liters – multiply by 3.7854
Liters to UK fluid ounces – multiply by 35.1961
Liters to US fluid ounces – multiply by 33.8150
Liters to UK pints – multiply by 1.7598
Liters to US pints – multiply by 2.1134
Liters to UK gallons – multiply by 0.2199
Liters to US gallons – multiply by 0.2642

Weight.

Ounces to grams – multiply by 28.3495
Pounds to kilograms – multiply by 0.4536
Grams to ounces – multiply by 0.0353
Kilograms to pounds – multiply by 2.2046

(Reference: The Chambers Dictionary)

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Public Aquariums

Most aquarists like to visit a public aquarium from time to time and once there are drawn to the marine areas. Usually the displays are excellent but not always, even the professionals can make mistakes or have mishaps.

My local public aquarium made a very basic mistake which was pointed out to them. In a large reef display they put a large number of damsel fish which looked very impressive at first. I say ‘at first’ because the numbers diminished quite rapidly. This was because they also introduced two rather large lionfish. Now, we all know what lionfish are likely to have for lunch don’t we. They did! Before all the small fish disappeared the lionfish were removed and now have their own smaller display aquarium.

Anyway, public aquariums are the place to see some excellent display aquariums in which creatures too large for a home system are kept. In addition there are often some reef systems on display which usually draw quite a few ‘oohs’.

The London public aquarium has various displays and the attached short video is one of them. At the beginning of the video is a water motion section, the movement presumably generated by some hefty timed pumps. Don’t worry about the colour, the video changes quickly.

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The Bubble Coral

This coral adds to all the differing shapes and colours of corals that could be added to the reef aquarium. It belongs to the stony or hard coral type.

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

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The Clown Trigger Fish

Though it is regularly seen in public aquariums, this fish is not commonly kept by aquarists. It is successfully kept by a good many nonetheless.

Seeing this fish in a local fish shop or anywhere else is an experience, the shape, the colours, it is really something. Anytime I see one anywhere I spend quite some time looking.

The fish is commonly known as the clown trigger and properly called Balistoides conspicilum. Why is it called ‘trigger’? This is because of the dorsal fin, for security the fish can go into a rock crevice and raise the dorsal fin, the second spine locks it in place. To release itself the fish exerts pressure on this second spine – the trigger – freeing the locking mechanism.

These fish are not suited to a reef aquarium as they could make a meal of mobile invertebrates and maybe some sessile invertebrates as well. As a snack, if the clown trigger can catch smaller fish it could eat them too. This would really please the aquarist! In addition, the fish could decide that the carefully placed reef rocks need re-arranging, again not an action that will endear it to the aquarist. Another reason is that the fish needs a lot of swimming space and in most reef systems the reef takes up a great deal of seawater volume.

So it is clear the fish is suited to the larger fish only system. Those with small and medium aquariums should not attempt to keep the fish as it could grow to 20 inches (circa 50.75cm). Many clown trigger fish being sold in stores are small, often only 3 or 4 inches, so growth must be allowed for.  An aquarium of 100 gallons (circa 400 litres) net or larger is the size needed. This is a large system as the fish requires rocks that form caves so that it can find security, these rocks of course reduce net seawater gallonage. The rocks should be firmly positioned so that they will resist any attempted design changes. On the same theme, heaters that are in the display aquarium should have guards fitted; these are generally available and not expensive. In a fish only aquarium a sump is a definite advantage as first it provides an area where heaters can be placed out of harm’s way and secondly it increases the net gallonage of the system. It should be remembered though that when stocking is considered the seawater in the sump is ignored.

Stocking the aquarium needs care. The clown trigger is very territorial and will take exception to another trigger in their area (the aquarium!) and could do the same with other large fish. Designed for dealing with crabs and other prey with shells, the teeth of the fish give the impression that it is not for messing with. So the fish should only be kept with other large or larger very robust ones that are well able to take care of themselves. These other fish should be of a different colour and shape.

Clearly if the aquarist wishes to keep a fish only aquarium with a high number of varied fish types, the clown trigger is not a fish to choose.

When introducing fish to the aquarium for the first time the clown trigger should be the last one in, this creates the chance for all the fish to ‘accept’ each other. It is also very helpful if, on introduction, the clown trigger is smaller than all other fish present. On no account should the aquarium be overstocked.

An aquarist could introduce the fish and find that it is impeccably behaved and wonder what on earth all the cautions were about. Another aquarist could find the fish a total berserker! So it’s best to be prepared.

Feeding is easy as the fish will take just about anything on offer, though for a fish such as this brine shrimp and flake are a bit of an insult! Pieces of de-frozen fish, mussel meat, shrimp and the like are foods usually taken without problem. The fish is confident and can be fed from the fingers, but beware of those teeth, an aquarist can be forgiven for being nervous! It has been reported that hard shelled food should be given on occasion as this wears the teeth. The fish becomes quite tame and if movement is detected near the aquarium it will usually beg for food.

Over time the fish will be seen nearly all of the daytime hours in open water and becomes a real pet and a favourite. They are very hardy and long lived if attention is given to maintaining a high quality environment.

The aquarist who can provide a suitable environment for the clown trigger is lucky indeed. 

The link is to some pictures and text:

http://www.aquaticcommunity.com/marinefish/clowntriggerfish.php

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Large Aquarium!

Marine aquarists who have a successful system, no matter what the type, fish only or mixed reef, are mainly satisfied. A successful marine system can be stunning to see and this applies not only to aquarists who know ‘what goes on’ but to the uninitiated as well.

Big aquariums are not unusual nowadays. By big I mean really big. Most people have seen them, you know, the ones with the odd black tipped reef shark cruising about! They’re in public aquariums of course.

Home aquariums, though not on the scale as in the last paragraph, can also be big. Myself, I see ‘big’ as 6ft x 2ft x 2ft, but this size is not uncommon. Nowadays it goes considerably beyond that.

The link is to a video featuring an aquarium more than twice the length of the above. The measurements of the display aquarium are 13ft x 3ft x 2.5ft. Linked to the main aquarium are two others, a sump and a refugium. The sump measures 6ft x 5ft x 2ft, and the refugium 5ft x 1.5ft x 1.5ft. Some size system!

I’m too lazy to work out the seawater gallonage, but routine seawater change time must be quite something, somewhat more than a 5 gallon bucket!

There’s a lot of fish to be seen and some of them are quite big, however with an attached sump and refugium of those sizes the seawater quality should be high.

Many aquarists idly dream about a larger system, but the owner of this one didn’t mess about.

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Maintain And Watch

What kind of an aquarist are you? Are you a ‘hands-in’ tinkerer or a watcher, or perhaps a mixture of the two?

There’s nothing wrong with tinkering as long as it’s within reason. Constantly changing the reef for example is not going to do a lot for the security of the fish. There’s often an improvement that can be made, usually small. The early months in the life of an aquarium is when most tinkering is likely to occur.

Me, I’m a watcher. That’s not to say that I don’t tinker on occasion, but it isn’t very often. It is necessary to deal with the overgrowth of corals and the like or the display quality would begin to deteriorate because of changed and reduced seawater currents, and also the loss of light to lower corals. Normal routine maintenance often requires ‘hands-in’ for various reasons, usually powerhead intakes that have debris present.

What the living captive reef needs is stability of seawater parameters, lighting quality and time to develop. Seawater parameters are easy, routine checks confirm the situation. Lighting just needs a little maintenance and changes of bulb and/or tubes from time to time.

On the wild reef, barring storms and disasters, sometimes man-made, there isn’t any over-interference, there is stability of habitat.

My soft coral aquarium has been running for 6½ years. I do regular maintenance once weekly, so hands go in the seawater then if necessary. Apart from that the reef is left alone though it is of course monitored.

Closely looking at the visible reef rocks it can be seen that they are covered with various marine growths. On the surface is much coralline, though to be truthful there isn’t much rock surface to be seen. In addition are many, many short hard growths that look like sticks, about 1 inch long and 1/8 inch thick. At first I thought they might be small tube worms or anyway some kind of worm, but despite close observation I have not seen any evidence of any type of worm. I’ve tried reference books to no avail, also the internet. Being honest I’m not too bothered about identification as they are clearly not malignant and interesting enough.

On the underside of rocks when viewed at night (it seems easier to see them then) are lots of tiny tubeworms. This time they are clearly tubeworms as the tiny feathery heads can be seen, not the same shape as the big showy ones but a small fan about ½ inch or so in diameter, usually considerably smaller. I find these tube worms in my canister filter as well, during maintenance I do my best to protect them but a good few meet their doom.

When cleaning the canister filter I always have to rescue tiny shrimps, about ½ an inch long. They usually float on the seawater surface apparently trapped by the meniscus. I return them unharmed to the display aquarium, avoiding the attention of the fish. If the shrimps in the canister filter sink they are lost, I can’t retrieve them. There are growths that appear in the canister filter that are repeatedly destroyed during maintenance, though they re-appear. I have been unable to identify them.

I have one worm that lives at the top of the reef. It was not there when the aquarium started but appeared a year or so later, or that’s when I noticed the small tube anyway. The tube is now around 2 inches long maybe a little more, and around 3/8 of an inch in diameter. It is definitely a worm as it can be seen at the mouth of the tube, though it doesn’t come out. It is not a feather duster. What it does to feed itself is trail a sticky thin thread in the seawater current, when food becomes attached to the thread it winds it in and consumes it. At feeding time when brine or mysis shrimp are on the menu the thread looks like one of those commercial fisherman’s long hooked lines with a good catch. I’ve again been unable to determine what the worm properly is, so it’s called ‘Fisherworm’. Very technical!

Things appear in areas of the aquarium where they are not expected. Button polyps appeared well down the reef, not put there by me. I have ‘transplanted’ the odd few button polyps and they have developed into healthy groups. A coral or two appears out of the rocks, sometimes they thrive but often they disappear again. Strange creatures wander about mainly noticed at night; one in particular looks like a leading candidate for an alien movie. I’ve no idea what it properly is. There isn’t any damage on the reef in any part so it isn’t one of those unwanted pests.

One of the most beautiful appearances is a calcareous type alga that’s growing on the glass quite high up. Fortunately it’s not one of the viewing glasses that I clean. It is a whitish growth that is very similar to snowflakes joined together. The first time I noticed it the size was about ½ inch or so across, which increased to around 2 inches. Then it fell off and disintegrated. However, I note that it is back and growing, this time it is a little lower down and, hopefully, will remain attached.

There are many life forms that use my captive reef as home. I introduced the fish and major corals. Others have just appeared. Well, ‘just appeared’ cannot be correct can it!

When I set up the aquarium I didn’t use any live rock at all, but inert porous rock. Over a lengthy period this rock has become live, permitting me to close down the canister filter used for bio-filtration (I still run it but there isn’t any bio-media inside, it’s purely for surface agitation and additional seawater). The inert rock was interspaced with rocks attached to purchased corals. It is these coral rocks that must have been the entrance avenue for the life that has appeared. Coral rock is live rock after all.

So, I’m a watcher. Things appear and disappear, grow slowly or quickly. Little life forms scurry about, fish cruise quietly always ready for more food, corals sway in the currents, ‘dawn’ and ‘dusk’ come and go. I try and leave it alone.

Diminutive as it is, it’s a real living reef.

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