The Regal Tang
July 9, 2009
This fish in addition to the regal tang is also known as the blue surgeonfish, but is properly called Paracanthurus hepatus.
The fish must be known to just about every marine aquarist. It is a beautiful blue with a yellow tail, with darker shading along the edge of the dorsal fin and along the back. It is often seen in retailer’s shops at a small size and the blue is wonderful – a small shoal of them is something else. I read somewhere once that the fish is the ‘bluest thing on earth’. How true this is could be questionable but it gives the correct impression. The wondrous blue does fade however as the fish gets larger.
The link shows a photo:
http://www.flickr.com/photos/9184647@N02/2206772757/sizes/l/
Talking of size it is possible for the fish to grow to around 11¾ inches (circa 30cm) though it is not so likely to reach this size in a home aquarium.
Seawater quality needs to be high which is normal for all systems.
As with all surgeons it is necessary that the fish has plenty of space to swim, therefore it is not suited to a small aquarium. They could be purchased at a small size but as can be seen they grow. They are usually acceptable for a reef system but the reef must not be so large as to over-reduce the available swimming space.
The fish when swimming seems rather inefficient compared to most others, and sometimes seems to be trying not to float to the surface. This is normal and it can move if the necessity arises!
Unfortunately, the fish is reported as being very susceptible to ‘white spot’ and ‘velvet’. I don’t dispute this at all though when I kept one for a good many years I didn’t encounter any such problems. However, Peter had a problem with ‘white spot’ a good while ago and sadly lost some fish before he cured it. One of the survivors was the regal tang!
As said I used to have a regal tang. When I cleaned the aquarium viewing glass with an algae magnet the tang would slowly approach the moving magnet and follow it up and down. Slowly the colour of the fish changed the blue getting more and more pale until it suggested white. It would continue to follow the magnet up and down with fins erect in a very obvious threat posture. The fish was truly pale with rage! The plastic of the magnet was blue so it was presumably seen as an interloper. Among its tank mates, including other blue fish, the regal tang was peaceable though. Maybe it took exception to a square fish!
In the aquarium they are generally peaceful and good eaters. The will take flake and the usual frozen foods such as brine and mysis shrimp. It is essential though that a supply of algae is provided to keep them in good health and colour. If there is insufficient in the aquarium, which is likely, then the aquarist must provide a regular amount of Nori or similar which can be obtained from pet shops and also health food shops (humans eat it with toast apparently!). The fish will also eat blanched lettuce with gusto, though this is not as good as algae.
If the fish is selected carefully in the first place, the home aquarium is big enough and a suitable diet is provided, the regal tang is a good addition to the display.
The Powder Blue Surgeon
July 4, 2009
This surgeonfish is commonly called the powder blue though the proper name is Acanthurus leucosternon.
The fish is very attractive but should not be found in just any aquarium. For example, it would be wrong and cruel to have one in my reef as the aquarium is too small, and in addition the reef takes up too much of the free seawater space available for swimming making that too small. Many would say the fish should not be kept in an aquarium of less than 5ft (circa 152.5cm) by 2ft (circa 61cm) by 2ft. Subject to the fish load and the available swimming space it could be reasonable to bring the length of the aquarium down to 4ft (circa 122cm). Again the rockwork should leave plenty of swimming space for the fish. There is a further point and that is that in all aquariums the growth potential must be considered. When purchased the fish is likely to be fairly small but, in the wild at least, it has the potential to grow to about 12 inches (circa 30.5cm). It can be seen why larger aquariums are best for this fish.
To keep the fish healthy and happy it is important that seawater is kept at high quality, which is a requirement for any system anyway. Also as in any system, it is important to ensure the seawater is as oxygen rich as possible. This is done by ensuring that seawater movement is optimum so that air/water interfaces are fully efficient.
Only one powder blue should be kept in an aquarium as they could be, and usually are, aggressive and territorial. Further, the fish could take exception to any other surgeon fish present in the aquarium particularly another blue one (of any shade). The fish may even take exception to any other largish blue fish, surgeon or not. It has also been advised that butterflies could be attacked.
So it sounds as if the powder blue is a fish to be avoided. Not really, there are many aquarists who have found keeping one has not caused unfortunate problems. Environment and selection of suitable tank mates is very important, and it could be a good idea to introduce the powder blue to the tank as one of the final additions.
Initial selection of the fish is very important, as it is with all livestock. Time should be taken to ensure the fish is in good health with nothing present that could cause any questions to arise.
Feeding does not present any problems at all. The fish will readily accept the general fare that is offered most other fishes, such as de-frozen food and flake. However, in the wild they feed nearly entirely on algae and so it follows that in captivity algae should be available. In most aquariums the natural algae growth will be insufficient and therefore commercial produce is required. This could be in the form of dried Nori algae, for example, which comes in sheets. The sheet can be reduced in size if necessary and hung in the aquarium on a lettuce clip for the fish to eat. Any uneaten or loose Nori should not be left too long but removed and replaced with fresh. It is likely that if the sheet remains fixed in place it will be eaten, especially if there are other algae eaters present. The aquarist can soon judge the correct amount needed.
There are some marine fish that clearly let the aquarist know how they are feeling by their colouration and the powder blue is one of them. If the fish is a fairly deep blue and the head black then the fish is fine and happy. If the blue has turned pale and the usually black head grayish then the fish is off-colour (sorry, pun not intended! I should have said not well). Check for correct diet and enough of it, seawater quality and any sign of disease. In a high quality environment the fish is reasonably trouble free.
Assuming that the powder blue is not exposed to disease problems and is homed in a suitable situation it adds movement, shape and colour to the aquarist’s collection. Longevity should be good too.
The link provides some pictures of the powder blue, placing the mouse pointer on a picture enlarges it:
http://www.whatsthatfish.com/fish/396
The Dusky Dwarf
June 30, 2009
There are so many fish that could tempt an aquarist but many of them have an attribute or two that means they cannot be chosen.
One of the most beautiful fish types are the angels, for example the emperor angel (Pomacanthus imperator) and the queen angel (Holacanthus ciliaris). These are certainly beautiful but cannot be kept by many aquarists because they grow too large.
So the aquarist with a smaller aquarium has to ignore angelfish? Well, no fortunately not. There are some angelfish that are suited to smaller systems and are also beautiful. These angels are generally termed ‘dwarf’ and there are some really stunning ones. Surely the flame angelfish (Centropyge loriculus) is well known. There are a good few others.
The angel referred to in the title is commonly called the dusky angelfish or coral beauty, the proper name is Centropyge bispinosus.
As with other dwarf angels there isn’t a problem with eventual size as fully grown the fish could be around 4 inches (circa 10cm). On purchase the fish are likely to be in the region of 2 inches (circa 5cm). The fish should not be kept with others of its own kind as usually aggression will occur. It has been known for two dwarf angels to be kept in a smallish aquarium together without mishap but this is unusual and best avoided. If an attempt is to be made to keep two Centropyge types the two fish should differ in size and colouration. In particular, the aquarium should be large with plenty of rockwork which affords the fish many retreats and possibilities of territory. The dusky angel will usually settle down with other suitable fish without problem, though larger more aggressive fish could cause difficulty. Overall the fish is mainly peaceful but aggression could appear from time to time, though nothing usually comes of it.
http://animal-world.com/encyclo/marine/angels/CoralBeauty.php
As can be seen from the link picture the fish is lovely, though photographs don’t really do it justice. The colouration is not so much ‘in the face’ as, say, a flame angel’s, though lovely nevertheless. The colouration can vary a little, some fish are subdued and dusky, others brighter and more striking.
Keeping the fish is reasonably straightforward without any particular requirements except one. This is that though the fish is a general omnivore it should have access to algae. The fish likes to take algae from the aquarium viewing glass and rock surfaces but cannot be considered as a good algae controller. The overall diet should be varied even with algae present, consisting of marine flake, de-frozen brine and mysis shrimp and similar. Food enriched with spirulina algae is a good idea. As always seawater quality should be high. There should be rockwork installed that permits the fish to find a cave or similar for security. The fish is suitable for a reef system though like many fish it could nip at fan worms and possibly even some corals. Usually it is well behaved but there could be exceptions!
The fish when kept in a good environment is considered to be reasonably hardy. However, some aquarists consider it not to be an ideal beginner’s fish as some experience is needed first. This is because of the early mistakes, usually to do with seawater quality that a beginner could make.
Adding one of these fish to a suitable display will not disappoint the aquarist. As stated elsewhere by an unknown source, the dwarf angels are God’s gift to aquarists. It is easy to see why.
The Yellow Tang
June 16, 2009
This fish is one recognized by all marine aquarists; it is very popular and commonly kept. If a splash of colour is required then this is one of the fish to consider, it attracts the eye like a magnet does metal.
The fish is properly called Zebrasoma flavescens. It is yellow all over apart from a small white area in front of the tail; this is the ‘scalpel’.
The yellow tang could grow to 7½ inches (circa 19cm). As with all fish of this type it is not for every aquarist as swimming space is required. A small aquarium is not a home for it; a suggested minimum size is 3ft (circa 91.5cm) by 1.5ft (circa 45.75cm) by 1.5ft though larger is better. If the reef structure is large this will reduce the swimming space, so even if the aquarium itself seems large enough the actual free seawater space needs to be checked.
The yellow tang is reputedly one of the hardiest of the surgeon fishes. Of course high quality seawater needs to be provided at all times. Tank mates should be compatible though even so aggression could appear, but usually with needs properly met they are peaceable enough.
Feeding these fish is not difficult, they will usually take marine flake and de-frozen foods. However, it is essential that they receive adequate amounts of algae. In the aquarium some of this could be provided by natural growth and in this way the fish is useful in keeping algae down – it should eat filamentous algae. Aquarium algae are not normally present in sufficient quantity so the aquarist needs to provide the food in other ways. One of the best methods is to purchase sheets of dried algae such as Nori. One sheet or a part of it can be held in place by an aquarium clip and left. The fish should eat it enthusiastically. It is suggested that algae is fed at least every other day, though many aquarists place the food in the aquarium everyday to ensure the fish can take it at will – any sheet algae that breaks free should be re-fixed or removed and any uneaten after a full day removed.
Brightness and colour are usually present in a marine aquarium and this fish has them plus another, movement. Properly cared for they should ‘live long and prosper’.
The video gives information on care of the yellow tang. For those who want to see a photo of the fish click on the link.
http://commons.wikimedia.org/wiki/File:Zebrasoma_flavescens_Luc_Viatour.jpg
The Banggai Cardinal At Risk?
June 2, 2009
The Banggai Cardinal, properly called Pterapogon kauderni, is a fairly new fish for the salt water aquarium. The fish in the aquarium is fairly sedentary, but has lovely colouring, with black vertical striping on a silver body and a long forked tail, again silver/black. It has become popular for obvious reasons.
A while ago it seemed likely that supplies of this fish from the wild would dry up because it appeared that the wild fish was under threat. Not a happy situation if correct.
The ‘under threat’ problem arose because it is believed that around 700,000 of these fish are collected for the aquarium trade each year. When the total estimated population in the wild is considered the cause for concern becomes obvious, this number is 2,000,000, so most would agree that the collection ratio is high. The fish only come from one small part of the Pacific Ocean so there is considerable collection concentration. The fish are mouth brooders (like freshwater cichlids) so perhaps the ratio of successful births to adulthood is high. However, whether that is the case or not, the fish only raise a few fish at a time so the ‘threat’ isn’t reduced. Open spawning fish produce huge amounts of eggs, and others such as clownfish produce far more fry. So the danger of insufficient natural replacement seemed real.
CITES became involved and the situation was under discussion. It very much looked as though a CITES ban on the importation of the fish would occur, if this ban appeared all imports into the US and EU would be prohibited.
Supply would be reduced to aquarists breeding the fish (a not impossible task) and commercial breeding which is being done, though limited.
However, as CITES ban did not occur. A considerable amount of discussion and agreed cooperation has avoided this. The government of the area has undertaken to strictly manage the situation, which includes training of local collectors and control of the numbers of fish collected relative to the estimated wild population. Aquarium trade groups and monitoring authorities have also undertaken to be involved. CITES had declared the fish as ‘at risk’ without further current action.
It seems likely that the number of these fish being exported from the collection area will or has reduced. This could have an effect on price, but who is going to complain in a circumstance such as this? Home bred fish but mainly commercially bred ones should counteract any fish scarcity to an extent.
Combined discussion and action seems to have produced a sensible outcome, the fish are being protected and at the same time interested parties such as aquarists and collectors have not been locked out.
The link shows a picture of the fish and some breeding information:
http://www.geocities.com/capecanaveral/hangar/6279/RaiseBanggaiCardinal.html
Is Frozen Fish Food Beneficial To Fish Or Just Handy To Aquarists?
April 11, 2009
Unless the aquarium is a reef with corals only, then there are going to be fish present. Whatever species these fish are there will not be sufficient food in the aquarium to meet their needs.
One of the most pleasurable parts of keeping a marine aquarium is feeding the fish. Maybe this is because there is direct interaction between the fish and the aquarist. There are a few fish that have real characters and become pets individually, but most fish only respond to movement outside the aquarium as, after time has passed since their introduction, it triggers their food response. They come to the front of the aquarium – ‘Where is it then?’
Marine fish need more than just ‘some food’. They have evolved to eat a particular type of food on the wild reef, or they are omnivores. Having said that, most fish will respond to any food once they recognize it as food. This recognition may initially come from their tank mates’ reaction.
Marine fish need to eat generally what Mother Nature intended. This could be algae which is a good example as some fish, for example surgeons, need it to remain healthy. So the aquarist cannot simply decide that a particular food is good and sufficient simply because the fish eat it.
One of the best base or foundation foods is flake. Flake is formulated by nutritionists to generally supply all the protein etc that marine fish need. This doesn’t mean to say that this is all the fish get; the diet needs to be varied.
Most aquarists use frozen foods as a variation as it comes in all sorts of guises, either mixtures or particular types. Two types that are very popular are brine shrimp, preferably ‘enriched’, and mysis. I use them myself in addition to other types including flake.
Flake as said is produced to generally meet the needs of marine fish and can be said to be nutritious. What of frozen foods though?
Using frozen food is straightforward as it usually comes in blister packs that the aquarist can store in the freezer. Getting it ready to feed the fish is also easy, all that needs to be done is to release one blister, if necessary reduce the amount by cutting it when still frozen, and then place it in an egg cup or similar. After a little RO (reverse osmosis) water or seawater from the aquarium has been added the food thaws quickly. Frozen food should not be thawed in a microwave as it has been anecdotally reported that this reduces the nutrition value.
So the question about the food being handy for aquarists has been answered – it certainly is. But is it nutritionally good for the fish?
I am not qualified to talk about nutrition. However, I can sensibly speculate and turn to human frozen food to do so. I used to wonder if frozen food for our consumption would be as good as the fresh variety. I used to assume that it wasn’t, as surely fresh food must be best! However, nutritionists state that the answer depends on the age of the food when it was frozen, if it was lying around or in transit for a good period the nutritional value would decrease. If the food was frozen immediately or nearly immediately then the nutritional value would be equal to fresh or even better if the fresh type had been harvested a while ago.
So perhaps this could be applied to frozen fish food. When were, for example the brine shrimps, frozen? I would imagine that there will not have been much delay in applying the freezing process as shrimps of that size are not suitable for keeping out of water and when in water they would have been living. The same would apply for other types of ‘live’ frozen food. If the food was frozen immediately the nutritional value shouldn’t have deteriorated. The question of what food value existed pre-freezing, that is when in its live state, is another matter. Brine shrimp and similar are not said to be particularly nutritious though there is obviously nutrition present. They are also said to give valuable roughage. Sometimes they are sold as ‘enriched’ which means the shrimp were fed a rich diet, which should be reflected in the frozen state if the freezing process was not delayed.
There are other frozen foods besides shrimp varieties and I would guess that the same applies, when were they frozen?
I feel fairly certain that a nutritionist knowledgeable in this area would have a lot more to say. However, the consideration of ‘when was it frozen’ would seem to cover the basics at least.
‘Big’ To The Marine Aquarist
March 31, 2009
Most marine aquarists keep mixed reef aquariums, some of them are very small ‘nano’ systems and others could be six footers, large in the hobby world. There are a few who own aquariums even larger. Other aquarists have fish only systems that could be the same in size range to the captive reefs.
Mention ‘big’ and the reef aquarist thinks of a system larger than the one he/she already has, a huge affair maybe that looks like part of the Pacific Ocean has been transported for the aquarist’s personal use. Or perhaps thoughts turn to a more usually dimensioned system but still larger than the one already owned. I suppose its human nature to think this way.
There’s another meaning to ‘big’ though and this time it doesn’t refer to the aquarium size but to the livestock in the aquarium, specifically big fish. There are those who find keeping large fish fascinating and it is a side of the hobby that is often overlooked, as said most aquarists think of mixed reefs and small fish only systems.
Keeping big fish is a discipline in itself. Considering the diversity of size on the wild reef there is a fair choice, though it could be the larger fish are not so plentiful in local fish shops as demand is not so high. We’re not talking of the very large reef fish but those that are considerably larger than those usually kept in a reef or even a fish only aquarium.
Keeping large fish requires careful thought – there will not be as many for a start. There could be one or perhaps two or three. The stocking guidelines apply, it should be particularly remembered that the net seawater gallonage dictates the fish size/numbers that can be accommodated. So any rockwork that supplies a home for fish will reduce the gallonage. A sump will increase seawater gallonage (and quality) but should not be included in the stocking calculations as to do so could lead to too high stocking and subsequent aggression. The size of aquarium is obviously very important and a very large one, or the largest practically useful, should be obtained so that accommodation will not be excessively restricted. The guideline for the aquarium size is that its length should be four times that of the biggest fully grown fish and the depth and width at least twice the length of the biggest fish. The guidelines on aquarium placement also apply.
When considering the size of aquarium it is best to research the fish that are desired first. Fish grow and need more space, so knowing their eventual likely size will either cause a search for more suitable fish because the needed aquarium is too large, or confirm the intended size is adequate. The fish in the shop could be small, but to what size will it grow? Some grow quickly!
Lighting is not the consideration it is with a reef system. What is required is sufficient light for the fish to see and be seen. This is easily met by two aquarium length fluorescent tubes. They can be selected to enhance the fish colours; two that are usually good for this are ‘marine white’ and ‘actinic blue’. In addition, it is good to have a ‘dawn’ and ‘dusk’ sequence which is achieved with electric timers. One timer turns the blue tube on and off say one half hour before the white tube comes on and the same period after the white tube goes off. Flooding an aquarium with sudden light or plunging it into sudden darkness is not good management.
During the research of the fish temperament should be carefully considered. The fish could well be an interesting and beautiful one, but also very aggressive and/or a predator. Suitable tank mates have obviously to be found for such a fish or trouble will not be long in coming. Fish that grow large could be purchased at a considerably lesser size, but it is still incorrect to house the fish with fish that have a full grown smaller size. Fish in good conditions could and hopefully will have a long life – but not if there is a growing aggressive fish or predator in the aquarium.
Research should also cover the suggested captive diet of the fish, so the aquarist knows that he/she can cope with the demand – is it available locally and is it able to be stored in the home ready for use?
Big fish eat big and the filtration system has to cope with it. The filtration is that operated by the bacteria of course (the bio-filtration) which must be able to handle and convert the generated waste. In addition big fish are generally messy and mechanical filtration is usually required, the canister filter is probably the best choice. The canister filter should be large enough to cope with the amount of seawater present and one a little oversized will not go amiss. Some aquarists use two canister filters of appropriate size, one for purely mechanical filtration and one for bio-filtration. The bio-filtration unit will also have mechanical filtration to protect the bio area. With both filters, particularly the bio one, it is important to regularly clean the mechanical media and replace it if it is suspect.
Regular maintenance applies to the big fish aquarium as it does to any other. There is a need for regular seawater changes. The commencing guideline is 10% of the net system volume per week but the aquarist should adjust this if seawater quality is below that required. Cleanliness of the aquarium needs watching and seawater siphoned out on a routine change gives the opportunity to remove detritus – big fish as mentioned could be ‘messy’.
The words ‘seawater quality’ bring up an important piece of equipment that most certainly should not be missing on a big fish aquarium, and that is the protein skimmer. A model should be selected that is fully capable of dealing with the net system seawater volume, including any sump. An old guideline suggested that when purchasing a protein skimmer it should be capable of dealing with twice the seawater volume present, and if there is any doubt it is a good guideline to follow.
Again dealing with seawater quality there are five test kits that are required, ammonia (there should never be any reading present*), nitrite (there should never be any reading present*), and nitrate (which is best kept as low as possible but as a guideline should not rise above 30ppm, better 20ppm. Nitrate levels are usually kept in check by routine seawater changes). *Ammonia and nitrite will make an appearance in any maturation period required with a bio-filter.
Nitrate and the fact that big fish are big eaters have already been mentioned. If the aquarist finds that nitrate is rising despite reasonably sized routine seawater changes, then another piece of equipment could be considered and this is the denitrator. Basically the denitrator is a home for bacteria. The environment is maintained at a very low oxygen level and the bacteria require oxygen, therefore to obtain it they extract it from the nitrate which breaks this down. There are mainly two types, both commercially available. One is based on sulphur and requires no attention except to ensure that the slow flow of seawater through it is maintained. The other type requires feeding with supplied nutrients. Personally I prefer the sulphur type but it is a matter of personal choice. It could well be that a denitrator is not required.
It was stated in a previous paragraph that five test kits are needed and three have been mentioned. The other two are first a pH test. This is to check the alkalinity of the seawater. The guideline range is 8.1 to 8.4. Whichever it is, it should be stable. Routine seawater changes should assist with this. The final test is not really a kit as such, it is an instrument named a hydrometer. This checks the specific gravity (SG) of the seawater; the guideline suggests a range of 1.022 to 1.026. With a fish only aquarium it would be unusual for the top end of the SG range to be used. Using an SG of 1.022 is reported to be beneficial to fish as it is more detrimental to the well being of certain parasites. The SG chosen should be stable.
All the tests should be completed once a week; they are straightforward and not particularly time consuming.
Keeping big fish means the aquarist will not have so many to look at. However, it follows that there is more of each fish to see! In addition, it could be argued that the visual impact of the fish is greater. Many have beautiful colours. It is known that some of these bigger fish become real pets with individuality and personality and aquarists and their families become very attached to them.
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