Are Corals Best Kept On Their Own?

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.

What Is An Invertebrate?

To avoid becoming a squishy heap on the ground humans have a skeleton. Quite a good invention really, not having a skeleton would cause quite a few difficult problems.

Humans aren’t alone with the possession of a skeleton of course; there are all sorts of life forms that have one too, how about the elephant or man’s best friend the dog as just two examples.

Skeletons are not essential to life however; there are creatures that don’t use one at all. As a non-scientist I can say that they use a different method to maintain their body shape, I’m not sure how a scientist would put it. For example a shrimp has a hard outer shell rather than an inner skeleton.

Vertebrates, those that have a skeleton, are vastly outnumbered in the world. It is estimated that vertebrates are around 3% of the life forms in the world. It follows that a massive 97% (I just had to demonstrate my mathematical abilities) are invertebrates.

There are land dwelling insects such as spiders and worms, examples of well known invertebrates. In the cold sea there are huge numbers of plankton, anemones, sponges etc. The warm seas contain many better known (to the marine aquarist) invertebrate species, including filter feeding worms, shrimps, corals and sometimes very large anemones. It is with some anemones of course that the representatives of the vertebrate/invertebrate world have combined forces to mutual advantage; these are the clown fish with their selected hosts. There are other examples of this life style.

Invertebrates are very adaptable as demonstrated by the discovery of volcanic activity deep in the sea well beyond the sun’s light. Scientists used to accept that life basically depends on the availability of light from the sun, an example of which is that plant life uses the sun’s light to photosynthesize and grow, and then the plant life is eaten by a herbivore from which energy is obtained. Herbivores are then the prey for carnivores. They all basically depend on the plants and the sun. This belief has been changed by the life found near this deep volcanic activity, including filter feeding worms, mollusks, bacteria and crabs which depend not on the sun’s light but on heat and chemicals.*

Anyway marine aquarists, or rather those who maintain a reef system, keep various types of invertebrate including shrimps, corals, sponges, anemones, filter feeding worms etc. These very interesting life forms only ask for a few things for success, including high quality seawater, for the majority of corals and some others sufficient light of the correct spectrum, space to grow and freedom from predation. It is usually important to place for example corals in a position where they receive sufficient seawater flow.

It is worthwhile noting that all marine aquariums, big or small, fish only or reef, depend on invertebrates for their health and life. The bio-filtration system, whether this is live rock or canister filters, contains bacteria that deal with the toxins ammonia and nitrite. Without these bacteria the life in the aquarium would die. With live rock, further bacteria should be able to deal with the sometimes troublesome nitrate.

Those aquarists who make use of natural live rock could discover that they have invertebrate life forms in their aquariums that they didn’t import themselves or at least not intentionally. Some such as filter feeding worms could be welcome. Others such as the Aiptasia anemone are not welcome. The Mantis shrimp is another, though in this case it is worth keeping but needs re-housing to an area where problems won’t arise.

Invertebrates provide the aquarist with a chance to create a living reef at home, be this large or small, though compared to Mother Nature’s creations all home reefs are miniscule. Nevertheless, a successful home reef is wonderful to see.

(* Reference: Marine Invertebrates. Martyn Haywood & Sue Wells)

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How About An Apple?

Most marine aquarists are only too happy to have something different in their aquariums, as long as that something fits in with the current population.

The apple being talked of here is the Sea Apple which is definitely different! As can be seen it’s colourful too. An aquarist who has one will usually be fascinated by ‘the thing in the corner’. The Sea Apple has been available to aquarists for many years. I feel that the beginner aquarist should let experience build before keeping one, as a pure guess say about a year, or at least until the common general husbandry mistakes are no longer made and seawater quality is consistently high. This is important as will be seen.

‘Sea Apple’ is the common name; the proper one is Pseudocolochirus axiologus. They need the usual correct introduction to the aquarium, that is, acclimatization, and should not be exposed to air. They need to be handled gently but this of course is the same for all livestock.

The Sea Apple does not require reef lighting as it is not a coral but a species of sea cucumber. This can of course be confusing, the common name talks of ‘apple’ yet the species is ‘cucumber’. (This seems to happen from time to time, such as the Foxface fish (Lo vulpinus) that belongs to the rabbitfish family.) The Sea Apple is usually able to grow to about 4″ (circa 10cm) though there are larger species that grow to about 6″ (circa 15.25cm) or more though these are not so readily available and are more expensive.

The Sea Apple is able to move slowly around the aquarium and will do so until it is happy with its position, and this depends a lot on seawater flow. The flow doesn’t need to be very strong but moderate to brisk. This is because from the top centre a crown of feathery tentacles will appear and too strong a flow could cause problems. As said, the Sea Apple will make its choice and the final place could be a viewing glass, a corner, a rock or even the tube from a tubeworm. The aquarist has his or her preference for position, so keep those fingers crossed. The final position is likely to be between half way and the top of the aquarium. Once the Sea Apple has come to rest it should be left in peace unless the position is causing trouble to other livestock or presents a danger to the Sea Apple itself. It should not be irritated by the aquarist; this could be a real problem as will be seen.

The tentacles are used for feeding and are extended into the seawater column for this purpose. Fine particulate matter is captured and, one by one, the tentacles are passed into the mouth for removal of any food and then withdrawn, it’s a bit like a human sucking food off the fingers. This is a fairly slow process and is fascinating to observe.

The Sea Apple is quite hardy in a high quality environment and can live a long time. Many do fail though and this is to do with feeding, or rather the lack of it. In most aquariums there is insufficient suitable fine particulate matter in the seawater and therefore the Sea Apple doesn’t get enough to eat. This causes it to slowly shrink until it dies. Target feeding is needed, the frequency of which is best twice a day or more if the need is observed. There are plenty of commercial fine foods available that are suitable. All that is needed is for this food to be squirted into the seawater with a suitable instrument a little upstream from the Sea Apple when it has the tentacles extended, the food will then drift over them. If the seawater current is too high causing the food to pass too quickly, turning off the pumps for a short period will not do any harm. Any of the fine food that is not taken will drift off and could well be captured by corals.

Overall I would suggest that a reef system is the best aquarium for the Sea Apple to be introduced into. The reason is that there is a greater likelihood that there will not be any fish present that could nip at the tentacles, though this is not always the case. If the Sea Apple is excessively harassed then serious trouble could occur.

The problem that a Sea Apple could cause is very serious. If it is excessively harassed and stressed a toxin could be released that could, and likely will, kill the other livestock. Not a pleasant thought. That is why the Sea Apple should not be harassed excessively by the aquarist and its tank mates should be suitable. In addition it would be a good cautionary measure to protect the intakes of circulation pumps etc so that the Sea Apple cannot be accidentally damaged, this should be done before introduction.

Having said that, the Sea Apple should be a good introduction to a suitable high quality environment provided the aquarist has reasonable experience and feeding is given suitable attention.

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The Marine Betta

There are so many fish that are attractive and tempt the aquarist, from small to moderate to large in size. Some are aggressive, some sensitive but are they suitable for the aquarium? The answer of course is mainly ‘yes’, with the addition that they all need to have their preferred environment provided.

One fish that is not as brightly coloured as some others, but is colourful and very attractive nevertheless, is the marine betta, as can be seen at the following link. Another common name for the fish is marine comet. The proper name is Calloplesiops altivelis.

http://www.ozanimals.com/Fish/Comet/Calloplesiops/altivelis.html

The beta is covered in dots and has large finnage which is where the common names probably come from. When the fins are extended they look spectacular. These fish are capable of growing to around 6¼” (circa 16cm) so they are not for the small aquarium, if they are to be comfortably housed a 36″ (circa 91.5cm) aquarium or thereabouts is recommended. Normally only one beta should be kept. Their tank mates should be selected carefully as they are fairly shy and not at their best when housed with bold, high action and/or aggressive fish, the companions should be of a similar size or smaller. It is also best not to overcrowd the fish, which is good practice in any aquarium anyway – a lower fish population is advantageous.

Having said companions should be smaller, care is again needed as the beta could predate on much smaller fish. It tends to ambush them from whatever area it has decided to hide in. Care also needs to be taken with smaller crustaceans as these will sometimes be eaten.

Once the fish has settled in feeding is not normally a problem, good quality frozen food is usually accepted and often so is freeze dried food. There will no doubt always be exceptions, but flake food is not particularly attractive to them. The aquarist needs to observe the fish in the aquarium at feeding time, as is the practice anyway, as the beta could lose out to faster and greedier fish it is necessary to ensure it has fed sufficiently.

For the fish to settle well the aquarium must be furnished with rockwork, be this live rock or otherwise. The rockwork needs to be arranged so that there are one or two caves, preferably several, that are large enough for the fish to hide in and watch the outside world from.

A very bright halide lit reef aquarium is not ideal for the beta as it prefers moderate light – a reef that houses soft corals and is lit by fluorescents would be better, as would the lesser lit fish only system. The fish could become accustomed more or less to brighter light but in this circumstance is likely to hide away for longer periods. The natural habit of the fish is to hide away during the day, but in the lower lit aquarium the fish should be seen more often for longer periods.

When the fish is first introduced to the aquarium it is likely to hideaway for quite a period, most fish hideaway at first but the beta’s period could be longer. The fish should start to appear when ‘dusk’ occurs (that is, main lights off and actinics only on before lights out) or maybe it could be ‘dawn’. Whatever, it should settle provided it feels secure and the environment is of high quality and then be seen more.

The only defence the fish has (to my knowledge) is that when it feels threatened it will put its head into the rocks and leave only the tail and rear body showing. The markings on the rear end seem to be similar to a moray eel, and any potential aggressor will consider twice before mixing with those.

This lovely and interesting fish will be excellent for the aquarium provided its tank mates are suitable, the lighting isn’t too bright, there are suitable hiding places and the seawater is of high quality. The aquarist could need to search a little before a fish is located.

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Ouch! Know Your Enemy

Last week I was helping my neighbour move a broken up concrete garage base to make way for a new one. Because the lumps of concrete were pretty rough I wore protective gloves.

Without warning a pain similar I suppose to having a red hot needle stuck into me occurred on the inner wrist. The pain didn’t last long, about a second, so it wasn’t severe. The only word I uttered was ‘Ouch!’ I saw the wasp leave, somehow or other it had got caught between my wrist and the glove. Over a couple of days my wrist did swell to an extent, but there wasn’t a problem though the itching was an annoyance.

When it happened I tried to recall the standard remedy. I knew that a wasp and bee had opposite sting make-up, one being alkaline and the other acid. Should I dose the sting spot with milk or vinegar? I wasn’t sure so I did both.

Later I found that a bee sting is acid, so milk would be appropriate, and a wasp sting is alkaline, so vinegar would be appropriate. Pretty straightforward really and seldom a real problem unless the person involved is likely to severely adversely react and/or is stung many times.

Australians often take a bottle of vinegar to the beach in case of stings. There are some nasty life forms that could make their presence felt. Another way if vinegar isn’t present is to use urine so I’m told (so perhaps those few beers on the beach could help in more ways than one!).

Vinegar, milk and urine are not the correct medications for all venomous stings and bites etc.

Marine aquariums are to be found in many places around the world. In the US and EU they are very numerous. Considering livestock, there’s a few that could cause problems.

In the sea there are some dangerous creatures and some of these find their way into aquariums. For example the blue ringed octopus is kept by a few aquarists. This little octopus, properly called Hapalochlaena maculosa, is around the size of a golf ball and is attractive, though the rings only turn blue when it is about to attack or as a warning to another life form considered too close. The size makes it a possibility for inclusion in a suitable aquarium. However, it has a deadly bite because it injects toxin.

Another dangerous creature is the stonefish (one type is Synaneichthyes verrucosus). I have seen a stonefish for sale, though only once, but why anyone would want to keep one I don’t know. The fish is sedentary, sitting still waiting for prey. They look very like a rock. On the back of the fish are 13 grooved spines which inject toxin if they penetrate the skin, somewhat like hypodermic needles. The intensity of pain and subsequent problems is subject to an extent on the number of spines that penetrated the skin. The pain is stated to be excruciating.
 
A problem caused by a blue ringed octopus or a stonefish needs immediate medical attention or death could occur. There are other dangerous creatures in addition to the two mentioned.

Most of us marine aquarists don’t keep such life forms. There are a similar few that are kept but are not as dangerous perhaps, but dangerous nonetheless.

One such fish, and well known, is the common lionfish, properly called Pterois volitans. There are other types but the common lionfish is the most readily available. The body markings are quite striking and the finnage beautiful. In the aquarium they need careful selection of companions or the companions could be eaten! The fins are the problem to the aquarist; they are able to inject venom that causes great pain.

Another well known and commonly kept fish is the foxface, properly called Lo vulpinus. These fish are also colourful and are a ‘different’ addition to the aquarium because of their head shape, though why they should be called foxface I don’t know. The danger with these fish again lies with the venomous fin spines which are capable of injecting venom which could take a long time to heal.

Another commonly kept life form is not a fish this time, but a coral. It’s very innocuous looking and kept in very many aquariums from beginner to advanced. It is quite tolerant and is usually able to resist some errors made by beginning aquarists. They are the zoanthids or button polyps which come in various polyp sizes and colours, normally covering the upper surfaces of a rock. Who would think there could be any danger from these? The danger comes from the species Palythoa, Protopalythoa and related species. Many aquarists handle zoanthids without any problem – in fact, problems from handling are rare. The fact is that the mucus of these zoanthids contains a neurotoxin which could be very dangerous or deadly to the aquarist. It is known that some tribes used to dip their spears in the mucus for use in battle and hunting*. So when one of these polyp groups is to be handled at the very least the aquarist should be sure there aren’t any cuts and abrasions on the skin. Wearing suitable gloves would be better.

The aquarium inhabitants mentioned above aren’t the only potential dangers that could appear. What is necessary is that the aquarist knows the potential problem(s) that could be introduced with newly purchased livestock to ensure he or she is happy with the situation. More important the knowledge should ensure the aquarist takes precautions and exercises caution when carrying out maintenance etc. The knowledge about livestock comes from some simple pre-purchase research.

In addition it is necessary, like a good scout, to be prepared. So as the potential problem is known the aquarist can find out from the internet or other sources what course of action should be taken should a mishap occur. Obviously medical assistance could be required, but it is important to be able to take initial action, if any, to help control the problem before medical help is available. It is also important to be able to advise the medics what it is that has happened, for example a puncture from X fish that is known to carry venom. At the extreme it could save your life.

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Firefish

These little fish are really worthwhile owning for both interest and beauty. They are usually easy to obtain and don’t cost a king’s ransom.

Firefish are also commonly called fire gobies. The proper name for them is Nemateleotris xxxx. The reason I have shown the second part as x’s is because there is more than one type (this method is not common practice!). Probably the best known is Nemateleotris magnifica. The link shows photos of this fish:

http://fins.actwin.com/species/index.php?t=9&i=119

As said there is more than one type in this group, two more lovely types are Nemateleotris decora and Nemateleotris helfrichi.

The fish could grow to around 3 1/8 inches (circa 8cm). They stand out not only because of beauty but because they have a very long dorsal fin, or the front part of it anyway. They are a peaceful fish which should not cause difficulties with others or with reef livestock such as corals.

The downside with these fish is that they shouldn’t be kept with larger more boisterous and/or belligerent types. This means that a fish only system is usually unsuitable. If they are kept in such a way they are likely to be always nervous and not show their true colours properly. A nervous and stressed fish is more likely to succumb to disease or just fade away.

The best place for firefish to be housed is in a reef system. The fish need a cave that is deep inside the reef for security, which they can dive into if danger seems near. This is the problem with incorrect tank mates; the firefish could be mostly afraid to leave their cave and even if they do it will not be for any distance. In the reef system they should be kept with small quiet non-aggressive fish. As said there isn’t any danger to corals.

Stocking is straightforward with simple guidelines. The firefish should be one of the first fish into the aquarium so that it can settle before other fish arrive. They will select a cave deep in the reef and gain confidence. One firefish could be introduced, but in the wild they tend to live in pairs* so two could be introduced at the same time. More than two pairs could be introduced provided the aquarium is large (the minimum suggested size for a pair is 30 inches (circa 76cm). This way the flicking of the dorsal fin will probably be seen, this is thought to be a signaling device. It might be thought that the higher seawater circulation in a reef system would be a problem for the fish, but usually it isn’t, the recommended flow is medium to strong. Though it doesn’t usually cause a serious problem, strong lighting is not particularly liked; the preference of the firefish is for moderate intensity. However, if the firefish is unhappy it could select an area where the lighting is not so strong, these usually are present in most reef systems.

Feeding is not a problem normally. In nature the fish take food from the seawater column, mainly plankton. Of course this is not possible in an aquarium situation. However, if suitably sized food is floating in the current the fish will normally go for it. Marine flake, brine and mysis shrimp are suitable, plus any other foods that are similar. If live foods are available such as brine shrimp these will usually also be taken.

When the aquarist first introduces the firefish to the aquarium they are likely to dive into the rocks and disappear. However, after a time, maybe a day or so, they should re-appear and start to hover in the seawater column. At this early stage they will probably dive back into the rocks when the aquarist approaches. However, as time continues this should reduce and the fish could even commence to ‘beg’ for food as do many other species. The normal daytime practice is for the firefish to hang in the seawater column above the home cave location waiting for food to pass by.

The firefish is reported to be a ’jumper’, that is, it has been known to jump out of the aquarium. Why this should be is not certain, maybe more boisterous fish spooked them. When I kept firefish they never jumped at all – their companions were peaceable and small so perhaps that was the reason.

In a suitable environment firefish should not present any problems. They are usually easy to feed and provide, in addition to their beauty, a slightly different looking fish.

(*Reference: Marine Atlas. Helmut Debelius & Hans A. Baensch)

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The Foxface

The title ‘Foxface’ does belong to a marine fish, one that is fairly commonly kept though I suspect not a top favourite. Why it should be called a foxface I don’t really understand, or maybe it’s just me! I think at best it could be called ‘badgerface’, though the flow of the name isn’t so good.

Anyway it’s a rabbitfish (hey, there we go again!) and the proper name is Siganus vulpinus. Actually it’s the overall family of these fishes that are termed ‘rabbitfish’, why I have no idea. I can’t see the basis for that name either. (A surgeonfish has blades – ‘scalpels’ – near the tail so that makes sense.) I’ll stop nattering.

The fish is usually purchased from the retailers at quite a modest size, say 3 or 4 inches, and is suitable at this point for a fairly small aquarium of 3 feet +. The fish is capable of growing to about 9½ inches (circa 24.25cm) though usually less in captivity, so an initial aquarium size of 4 feet + would be better.

It needs to be noted that the foxface has venomous spines on the dorsal and anal fins. It’s necessary to ensure that the hand or arm does not come into contact with them during maintenance operations. The one I kept seemed to be particularly inquisitive when I needed to put a hand in the aquarium trying to come really close, so my wife kindly used a clean stick to gently keep it at a distance, which did the trick. No mishaps (that is me jumping about holding an arm!) ever occurred. Better safe than sorry.

The foxface is likely to be aggressive towards one of its own kind so it is best kept singularly. They are suitable for a fish only or reef system. As with most fish it needs a secure hole to hide in – having said that the one that I had would jam itself behind the same filter every night, keeping itself in position by curling its body. At first I was very concerned as the colours faded very markedly at night, however I learned that this is a normal situation and the fish was always out in the morning back to normal colouration.

The foxface is easy to feed as they will accept just about anything that is on offer, which usually includes flake, de-frozen brine and mysis shrimp etc. This is fine but it is important to offer food containing algae as well, such as ‘spirulina enriched’ types. In addition, blanched lettuce fixed to a clip is usually accepted. However, it’s always best to offer algae – the fish is likely to take algae available in the aquarium but this is more than likely going to be insufficient. Sheets of algae such as Nori can be purchased and these can be fixed to a lettuce clip and left for the fish to browse on. If there are surgeonfish in the aquarium as well they will also take it. The aquarist will soon learn from experience how much to put in.

In the aquarium the foxface offers colour and a different shape, to an extent anyway, behind the head it is a lovely yellow colour in total, with a long black-topped snout, underneath is a length of white, then black again. Here’s the fish:

http://commons.wikimedia.org/wiki/Image:Siganus_vulpinus_2.jpg

Now, why is it called a foxface in a family of rabbitfish…?

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